cssi/SciSciGPT-SciSciNet huggingface dataset:
STELLAR: A Generic EM Side-Channel Attack Protection through Ground-Up Root-cause Analysis

The threat of side-channels is becoming increasingly prominent for resource-constrained internet-connected devices. While numerous power side-channel countermeasures have been proposed, a promising approach to protect the non-invasive electromagnetic side-channel attacks has been relatively scarce. Today’s availability of high-resolution electromagnetic (EM) probes mandates the need for a low-overhead solution to protect EM side-channel analysis (SCA) attacks. This work, for the first time, performs a white-box analysis to root-cause the origin of the EM leakage from an integrated circuit. System-level EM simulations with Intel 32 nm CMOS technology interconnect stack, as an example, reveals that the EM leakage from metals above layer 8 can be detected by an external non-invasive attacker with the commercially available state-of-the-art EM probes. Equipped with this ‘white-box’ understanding, this work proposes STELLAR: Signature aTtenuation Embedded CRYPTO with Low-Level metAl Routing, which is a two-stage solution to eliminate the critical signal radiation from the higher-level metal layers. Firstly, we propose routing the entire cryptographic core within the local lower-level metal layers, whose leakage cannot be picked up by an external attacker. Then, the entire crypto IP is embedded within a Signature Attenuation Hardware (SAH) which in turn suppresses the critical encryption signature before it routes the current signature to the highly radiating top-level metal layers. System-level implementation of the STELLAR hardware with local lower-level metal routing in TSMC 65 nm CMOS technology, with an AES-128 encryption engine (as an example cryptographic block) operating at 40 MHz, shows that the system remains secure against EM SCA attack even after 1M encryptions, with 67% energy efficiency and 1.23× area overhead compared to the unprotected AES.
Coifman–Meyer multipliers: Leibniz-type rules and applications to scattering of solutions to PDEs

Leibniz-type rules for Coifman-Meyer multiplier operators are studied in the settings of Triebel-Lizorkin and Besov spaces associated to weights in the Muckenhoupt classes. Even in the unweighted case, improvements on the currently known estimates are obtained. The flexibility of the methods of proofs allows to prove Leibniz-type rules in a variety of function spaces that include Triebel-Lizorkin and Besov spaces based on weighted Lebesgue, Lorentz and Morrey spaces as well as variable-exponent Lebesgue spaces. Applications to scattering properties of solutions to certain systems of partial differential equations involving fractional powers of the Laplacian are presented.
Semi-supervised Acoustic Event Detection Based on Tri-training

This paper presents our work of training acoustic event detection (AED) models using unlabeled dataset. Recent acoustic event detectors are based on large-scale neural networks, which are typically trained with huge amounts of labeled data. Labels for acoustic events are expensive to obtain, and relevant acoustic event audios can be limited, especially for rare events. In this paper we leverage an Internet-scale un-labeled dataset with potential domain shift to improve the detection of acoustic events. Based on the classic tri-training approach, our proposed method shows accuracy improvement over both the supervised training baseline, and semi-supervised self-training set-up, in all pre-defined acoustic event detection tasks. As our approach relies on ensemble models, we further show the improvements can be distilled to a single model via knowledge distillation, with the resulting single student model maintaining high accuracy of teacher ensemble models.
Mesolimbic dopamine projections mediate cue-motivated reward seeking but not reward retrieval in rats

Efficient foraging requires an ability to coordinate discrete reward-seeking and reward-retrieval behaviors. We used pathway-specific chemogenetic inhibition to investigate how rats' mesolimbic and mesocortical dopamine circuits contribute to the expression and modulation of reward seeking and retrieval. Inhibiting ventral tegmental area dopamine neurons disrupted the tendency for reward-paired cues to motivate reward seeking, but spared their ability to increase attempts to retrieve reward. Similar effects were produced by inhibiting dopamine inputs to nucleus accumbens, but not medial prefrontal cortex. Inhibiting dopamine neurons spared the suppressive effect of reward devaluation on reward seeking, an assay of goal-directed behavior. Attempts to retrieve reward persisted after devaluation, indicating they were habitually performed as part of a fixed action sequence. Our findings show that complete bouts of reward seeking and retrieval are behaviorally and neurally dissociable from bouts of reward seeking without retrieval. This dichotomy may prove useful for uncovering mechanisms of maladaptive behavior.
Inhibition of sodium–glucose cotransporter-2 preserves cardiac function during regional myocardial ischemia independent of alterations in myocardial substrate utilization

The goal of the present study was to evaluate the effects of SGLT2i on cardiac contractile function, substrate utilization, and efficiency before and during regional myocardial ischemia/reperfusion injury in normal, metabolically healthy swine. Lean swine received placebo or canagliflozin (300 mg PO) 24 h prior to and the morning of an invasive physiologic study protocol. Hemodynamic and cardiac function measurements were obtained at baseline, during a 30-min complete occlusion of the circumflex coronary artery, and during a 2-h reperfusion period. Blood pressure, heart rate, coronary flow, and myocardial oxygen consumption were unaffected by canagliflozin treatment. Ventricular volumes remained unchanged in controls throughout the protocol. At the onset of ischemia, canagliflozin produced acute large increases in left ventricular end-diastolic and systolic volumes which returned to baseline with reperfusion. Canagliflozin-mediated increases in end-diastolic volume were directly associated with increases in stroke volume and stroke work relative to controls during ischemia. Canagliflozin also increased cardiac work efficiency during ischemia relative to control swine. No differences in myocardial uptake of glucose, lactate, free fatty acids or ketones, were noted between treatment groups at any time. In separate experiments using a longer 60 min coronary occlusion followed by 2 h of reperfusion, canagliflozin increased end-diastolic volume and stroke volume and significantly diminished myocardial infarct size relative to control swine. These data demonstrate that SGLT2i with canagliflozin preserves cardiac contractile function and efficiency during regional myocardial ischemia and provides ischemia protection independent of alterations in myocardial substrate utilization.
Resident Perspectives on Teaching During Awake Surgical Procedures.

Introduction Residents learn technical and communication skills during training and practice both concurrently during awake surgical procedures. Patients have expressed mixed views on resident involvement in their surgical care, making this context challenging for residents to navigate. We sought to qualitatively explore resident perspectives on teaching during awake surgical procedures. Methods Residents in Urology, Obstetrics and Gynecology, and General Surgery who had been exposed to 10 or more awake surgical procedures were recruited for recorded focus groups at the University of Chicago. Recordings were transcribed, coded, and reviewed by 3 researchers using the constant comparative method until thematic saturation was reached. Results Twenty-five residents participated in 5 focus groups. Residents identified positive educational techniques during awake surgery including preprocedural communication, explaining teaching and the resident role, whispering/nonverbal communication, involving the patient in education, and confident educator. Residents described challenges and failures in education, including hesitating to ask questions, hesitating to correct a learner, whispering/nonverbal communication, and taking over. In discussing informed consent during awake procedures, some residents described that the consent process should or did change during awake procedures, for example, to include more information about the resident role. Conclusions Residents participating in awake surgical procedures offer new insights on successful techniques for teaching during awake surgery, emphasizing that good communication in the procedure room starts beforehand. They also identify challenges with teaching in this context, often related to a lack of open and clear communication.
A Control of Localized Surface Phonon Polariton Resonance Using Metal/Dielectric Multilayer Boundary

We fabricated subwavelength grating of a metal/dielectric multilayer on silicon carbide. We experimentally demonstrated a control of localized surface phonon polariton resonance showing near perfect infrared absorption at the optical phonon band of silicon carbide.
Fission yeast TRP channel Pkd2p localizes to the cleavage furrow and regulates cell separation during cytokinesis.

Fission yeast TRP channel Pkd2p is the homologue of human polycystins. The pkd2 mutant exhibits defects in the contractile ring closure and cell separation during cytokinesis. This essential protei...
IMPROVED SYNTHESIS OF 2-CHLORO- AND 2, 9-DICHLORO-1, 10-PHENANTHROLINES

(2007). IMPROVED SYNTHESIS OF 2-CHLORO- AND 2, 9-DICHLORO-1, 10-PHENANTHROLINES. Organic Preparations and Procedures International: Vol. 39, No. 6, pp. 603-608.
A NOVEL SYNTHESIS OF 3'-DEOXY-3'-NITROTHYMIDINE VIA NUCLEOPHILIC SUBSTITUTION WITH NITRITE ANION

Nucleophilic substitution at C3′ of 1-(2-deoxy-5-O-trityl-β-D-erythr-pentofuranosyl)-2-methoxy-5-methyl-4(1H)-pyrimidinone (5) with methyl iodide/triphenylphosphine/diethyl azodicarboxylate gave the expected inverted iodide 6 and minor epimer 7. Treatment of 6 with lithium nitrite/phloroglucinol yielded the desired nitro derivative 8 and subsequent acidic deprotection afforded the title compound 1. This represents a novel method for the introduction of a nitro group into the furanosyl moiety of a nucleoside. The nmr spectroscopic techniques (COSY, NOESY, nOe, HMQC and HMBC) were used to determine the stereochemistry at C3′ of the nucleosides. Spectral analysis of H-D exchange at the 3′-position of 1 did not indicate the formation of its epimer 10.
A new asymmetric 1,4-addition method: application to the synthesis of the HIV non-nucleoside reverse transcriptase inhibitor DPC 961

Abstract The asymmetric synthesis of the HIV non-nucleoside reverse transcriptase inhibitor (NNRTI) DPC 961 is achieved in three steps with an overall yield of >55%. The asymmetry is induced by the chiral auxiliary (R)-(+)-α-methylbenzylamine, utilizing a new asymmetric 1,4-addition protocol.
Chiral catalysts for enantioselective carbenoid cyclopropanation reactions

Chiral copper(I) and rhodium(II) catalysts designed to achieve enantioselection in cyclopropanation reactions have recently been reported. These catalysts react with diazo compounds to form intermediate metal carbenes that subsequently react with alkenes, in both intermolecular and intramolecular transformations, to form cyclopropane derivatives. They are constructed with chiral ligands whose function is to orient carbene substituents and control olefin approach to the carbenoid center. Enantioselectivities that are greater than 95% have been achieved. In this review, the major advances in chiral catalyst design and development are described, and a uniform mechanistic interpretation is advanced to explain the results accumulated in reported investigations. Focus is placed on chiral salicylaldimine and semicorrin/bis-oxazoline copper catalysts and on the newest class of chiral catalysts for enantioselective carbenoid reactions, rhodium(II) carboxamides. Although early in their development, sufficient advances have been made to justify placement of this catalytic methodology among the most promising for enantioselective cyclopropanation reactions.
Synthesis of 1,2,5,6-Tetrahydro-3-pyridinylalanine: A Key Intermediate in the Preparation of Thrombin Inhibitor UK-239,326

Abstract A short synthesis of N-protected 1,2,5,6-tetrahydro-3-pyridinylalanine derivatives (8–10) was accomplished using a simple procedure of quaternization of (3-pyridyl)alanine 6 with benzyl bromide followed by reduction with NaBH4. Amino acid 10 was then converted to thrombin inhibitor UK-239,326 (2), which required the sequential functionalization of four amines to give four different functional groups (viz., sulfonamide, carboxamide, guanidine, and methylamine).
A divergent approach to the myriaporones and tedanolide: Enantioselective preparation of the common intermediate

Abstract The tedanolide and myriaporone classes of natural products represent interesting targets for synthesis because of their structural similarity and biological activity. The asymmetric preparation of a potential common intermediate in the total synthesis of each of these targets is presented. The key step, a Zr-mediated allylation, allows for the efficient preparation of the hydroxypropionate structural unit.
Preparation of β-phenylnitroethanes having electron-donating aryl substitution

Abstract β-Phenyl-β-hydroxynitroethanes having activating aryl substituents are treated with triethylsilane/trifluoroacetic acid under solventless conditions to give the corresponding phenylnitroethanes. Substrates having no aryl substituents or substituents that are only mildly activating or deactivating do not result in appreciable conversion to the title compounds.
Unusual polyoxygenated sterols from a Philippines sponge Xestospongia sp.

Abstract Two novel sulfated sterols, ibisterol sulfates B ( 3 ) and C ( 4 ), and an unprecedented non-sulfated sterol, 4β,5β-epoxy-2β,3α,12β,22 S -tetrahydroxy-14α-methylcholest-7,9(11)-dien-6,24-dione ( 5 ) have been isolated from a Xestospongia sp. collected in the Philippines. The structures were elucidated using spectroscopic data. These sterols were found to be inhibitors of HIV-1 integrase.
Hip circumduction is not a compensation for reduced knee flexion angle during gait.

Abstract It has long been held that hip abduction compensates for reduced swing-phase knee flexion angle, especially in those after stroke. However, there are other compensatory motions such as pelvic obliquity (hip hiking) that could also be used to facilitate foot clearance with greater energy efficiency. Our previous work suggested that hip abduction may not be a compensation for reduced knee flexion after stroke. Previous study applied robotic knee flexion assistance in people with post-stroke Stiff-Knee Gait (SKG) during pre-swing, finding increased abduction despite improved knee flexion and toe clearance. Thus, our hypothesis was that hip abduction is not a compensation for reduced knee flexion. We simulated the kinematics of post-stroke SKG on unimpaired individuals with three factors: a knee orthosis to reduce knee flexion, an ankle-foot orthosis commonly worn by those post-stroke, and matching gait speeds. We compared spatiotemporal measures and kinematics between experimental factors within healthy controls and with a previously recorded cohort of people with post-stroke SKG. We focused on frontal plane motions of hip and pelvis as possible compensatory mechanisms. We observed that regardless of gait speed, knee flexion restriction increased pelvic obliquity (2.8°, p
A convenient synthesis of 8-substituted indolizines as precursors to 5-substituted cycl{3.2.2}azine derivatives

The synthesis of 8-substituted indolizines is described via a two step process in which a 1,4-diketone, containing a rerf-butyl group, is cyclocondensed with a trialkylsilyl protected pyrrole to provide 5,8-disubstituted indolizines in higher yields than the identical reaction with unprotected pyrrole. Cleavage of the tert-butyl group from the indolizine 5-position, by treatment with 85% phosphoric acid, provides 8-substituted indolizines in good yields. Treatment of 8-substituted indolizines with dimethyl acetylenedicarboxylate, in the presence of palladium-on-carbon, provides novel 5-substituted cycl{3.2.2) derivatives.
Feasibility of topological data analysis for event-related fMRI

Recent fMRI research shows that perceptual and cognitive representations are instantiated in high-dimensional multivoxel patterns in the brain. However, the methods for detecting these representati...
Dynamics of microbial community composition and soil organic carbon mineralization in soil following addition of pyrogenic and fresh organic matter.

Pyrogenic organic matter (PyOM) additions to soils can have large impacts on soil organic carbon (SOC) cycling. As the soil microbial community drives SOC fluxes, understanding how PyOM additions affect soil microbes is essential to understanding how PyOM affects SOC. We studied SOC dynamics and surveyed soil bacterial communities after OM additions in a field experiment. We produced and mixed in either 350 °C corn stover PyOM or an equivalent initial amount of dried corn stover to a Typic Fragiudept soil. Stover increased SOC-derived and total CO2 fluxes (up to 6x), and caused rapid and persistent changes in bacterial community composition over 82 days. In contrast, PyOM only temporarily increased total soil CO2 fluxes (up to 2x) and caused fewer changes in bacterial community composition. Of the operational taxonomic units (OTUs) that increased in response to PyOM additions, 70% also responded to stover additions. These OTUs likely thrive on easily mineralizable carbon (C) that is found both in stover and, to a lesser extent, in PyOM. In contrast, we also identified unique PyOM responders, which may respond to substrates such as polyaromatic C. In particular, members of Gemmatimonadetes tended to increase in relative abundance in response to PyOM but not to fresh organic matter. We identify taxa to target for future investigations of the mechanistic underpinnings of ecological phenomena associated with PyOM additions to soil.
FIBERNET 2.0: An automatic neural network based tool for clustering white matter fibers in the brain

The brain's white matter fiber tracts are impaired in a range of common and devastating conditions, from Alzheimer's disease to brain trauma, and in developmental disorders such as autism and neurogenetic syndromes. Many studies now examine the connectivity and microstructure of the brain's neural pathways, spurring the development of algorithms to extract and measure tracts and fiber bundles. Clustering white matter (WM) fibers, from whole-brain tractography, into anatomically meaningful bundles is still a challenging problem. Existing tract segmentation methods use atlases or regions of interest (ROI) or unsupervised spectral clustering. Even so, atlas-based segmentation does not always partition the brain into a set of recognizable fiber bundles. Deep learning techniques can be applied to automatically segment and cluster white matter fibers. Here we propose a robust approach using convolutional neural networks (CNNs) to learn shape features of the fiber bundles, which we then exploit to cluster WM fibers into bundles. In a range of tests across diverse fiber bundles, we illustrate the accuracy of our method, and its ability to suppress false positive fibers.
Black hole remnants and dark matter

Abstract We argue that, when the gravity effect is included, the generalized uncertainty principle (CUP) may prevent black holes from total evaporation in a similar way that the standard uncertainty principle prevents the hydrogen atom from total collapse. Specifically we invoke the GUP to obtain a modified Hawking temperature, which indicates that there should exist non-radiating remnants (BHR) of about Planck mass. BHRs are an attractive candidate for cold dark matter. We investigate an alternative cosmology in which primordial BHRs are the primary source of dark matter.
Linear relationship between peak and season-long abundances in insects

An accurate quantitative relationship between key characteristics of an insect population, such as season-long and peak abundances, can be very useful in pest management programs. To the best of our knowledge, no such relationship has yet been established. Here we establish a predictive linear relationship between insect catch Mpw during the week of peak abundance, the length of seasonal flight period, F (number of weeks) and season-long cumulative catch (abundance) A = 0.41MpwF. The derivation of the equation is based on several general assumptions and does not involve fitting to experimental data, which implies generality of the result. A quantitative criterion for the validity of the model is presented. The equation was tested using extensive data collected on captures of male gypsy moths Lymantria dispar (L.) (Lepidoptera: Erebidae) in pheromone-baited traps during 15 years. The model was also tested using trap catch data for two species of mosquitoes, Culex pipiens (L.) (Diptera: Culicidae) and Aedes albopictus (Skuse) (Diptera: Culicidae), in Gravid and BG-sentinel mosquito traps, respectively. The simple, parameter-free equation approximates experimental data points with relative error of 13% and R2 = 0.997, across all of the species tested. For gypsy moth, we also related season-long and weekly trap catches to the daily trap catches during peak flight. We describe several usage scenarios, in which the derived relationships are employed to help link results of small-scale field studies to the operational pest management programs.
Microwave synthesis of α-cyano chalcones

Abstract A novel methodology for facile production of α-cyano chalcones under microwave irradiation is described. Utilizing a Knoevenagel condensation between benzoylacetonitriles and aromatic aldehydes, substituted chalcones are generated via a 15-min, one-pot synthesis. Diversification of aromatic groups, including electron-withdrawing, electron-donating, and heterocyclic substitutions, has led to the isolation of over twenty colored, solid chalcone products. Furthermore the methodology can be extended to the synthesis of benzylidenemalononitriles as well as methyl and ethyl α-cyano cinnamates.
A Type I Restriction-Modification System Associated with Enterococcus faecium Subspecies Separation.

Enterococcus faecium is a leading cause of hospital-acquired infections around the world. Rising antibiotic resistance in certain E. faecium lineages leaves fewer treatment options. The overarching aim of this work was to determine whether restriction-modification (R-M) systems contribute to the structure of the E. faecium species, wherein hospital-epidemic and non-hospital-epidemic isolates have distinct evolutionary histories and highly resolved clade structures. R-M provides bacteria with a type of innate immunity to horizontal gene transfer (HGT). We identified a type I R-M system that is enriched in the hospital-epidemic clade and determined that it is active for DNA modification activity and significantly impacts HGT. Overall, this work is important because it provides a mechanism for the observed clade structure of E. faecium as well as a mechanism for facilitated gene exchange among hospital-epidemic E. faecium isolates.
Structural elucidation of an oxazolo[5,4-b]pyridine : an alternative cyclization product related to nevirapine

An unexpected cyclization product was isolated in the final step of the synthesis of nevirapine, a non-nucleoside inhibitor of HIV-1 reverse transcriptase. Based on infrared spectrometry, mass spectrometry, and a number of two-dimensional nmr experiments, the structure of this product was assigned to be 2-((2′-cyclopropylamino)-3′-pyridyl)-7-methyloxazolo[5,4-b]pyridine, 9. Results of a single crystal X-ray analysis confirmed this structural assignment. This product arises from cyclization of N-(2-chloro-4-methyl-3-pyridyl)-2-(cyclopropylamine)-3-pyridinecarboxamide, 8, by displacement of the chlorine with the amide carbonyl oxygen. A competitive reaction occurs when 8 is deprotonated prior to cyclization to form nevirapine, 11-cyclopropyl-5,11-dihydro-4-methyl-6H-dipyrido[3,2-b:2′,3′-e][1,4]diazepin-6-one, 2.
The use of vinyl imidazoles as Diels-Alder dienes

Abstract The first use of a vinylimidazole as a Diels-Alder diene is reported. Semiempirical calculations are used to characterize 1-methyl-5-vinylimidazole as an electron-rich diene.
Shortened Lifespan and Other Age-Related Defects in Bang Sensitive Mutants of Drosophila melanogaster.

Mitochondrial diseases are complex disorders that exhibit their primary effects in energetically active tissues. Damage generated by mitochondria is also thought to be a key component of aging and age-related disease. An important model for mitochondrial dysfunction is the bang sensitive (bs) mutants in Drosophila melanogaster Although these mutants all show a striking seizure phenotype, several bs mutants have gene products that are involved with mitochondrial function, while others affect excitability another way. All of the bs mutants (parabss , eas, jus, ses B, tko are examined here) paralyze and seize upon challenge with a sensory stimulus, most notably mechanical stimulation. These and other excitability mutants have been linked to neurodegeneration with age. In addition to these phenotypes, we have found age-related defects for several of the bs strains. The mutants eas, ses B, and tko display shortened lifespan, an increased mean recovery time from seizure with age, and decreased climbing ability over lifespan as compared to isogenic CS or w1118 lines. Other mutants show a subset of these defects. The age-related phenotypes can be rescued by feeding melatonin, an antioxidant, in all the mutants except ses B The age-related defects do not appear to be correlated with the seizure phenotype. Inducing seizures on a daily basis did not exacerbate the phenotypes and treatment with antiepileptic drugs did not increase lifespan. The results suggest that the excitability phenotypes and the age-related phenotypes may be somewhat independent and that these phenotypes mutants may arise from impacts on different pathways.
Regio- and Stereoselective Synthesis of β-d-Gluco-, α-l-Ido-, and α-l-Altropyranosiduronic Acids from Δ4-Uronates

The stereoselective synthesis of β-d-glucopyranosiduronic, α-l-idopyranosiduronic, and α-l-altropyranosiduronic acids has been performed from different Δ4-uronate monosaccharides. Bromination of the C-4,5 double bond provided the trans-diaxial bromohydrin derivatives, which were converted to the corresponding epoxides in high yields. Direct reduction of the epoxides using borane−tetrahydrofuran complex led to the corresponding glucuronic acids in low to good yields. Glucuronic acids were also obtained in satisfactory yields through a two-steps procedure involving bromination of the epoxide with titanium(IV) bromide followed by reduction using tributyltin hydride. Lewis acid-catalyzed rearrangement of these epoxides led to the corresponding α-l C-4 ketopyranosides adopting the 1C4 chair conformation. Hydride reduction afforded the α-l-idopyranosiduronic or the α-l-altropyranosiduronic acids, the stereoselectivity of the reduction being controlled by the appropriate substitution pattern.
Optical Anion Sensors Based on Alkyne-Linked, Functionalized Calix[4]pyrroles

Linking a calix[4]pyrrole anion recognition subunit to chromophores or fluorophores via an alkynyl spacer attached to a β-pyrrolic position of a calix[4]pyrrole core produces a new class of anion sensor that permits the detection of halide and phosphate anions in organic media via direct, so-called "naked-eye" visualization or fluorescence quenching-based spectroscopic means.
Synthesis and Chemistry of Quinone Methide Models for the Anthracycline Antitumor Antibiotics

In an effort to further understand the chemistry of anthracycline-type quinone methides, two tetracyclic o-quinone methides, 4,5,12-trimethoxy-11-[(trimethylacetyl)oxy]-9,10-dihydro-6(2H)-naphthacenone (19) and (±)-9-carbomethoxy-4,5,12-trimethoxy-11-[(trimethylacetyl)oxy]-9,10-dihydro-6(2H)-naphthacenone (20), were synthesized, and their reaction with several nucleophiles was investigated. Carbon- and sulfur-based nucleophiles afforded stable adducts while oxygen- and nitrogen-based nucleophiles afforded unstable adducts due to the reversibility of the addition. Adducts of 19 with ethanol and O-silylated adenosine (27) were acetylated to afford stable phenol acetates 21 and 29, respectively.
BaCe1-xPdxO3-δ (0 ≤ x ≤ 0.1): Redox Controlled Ingress and Egress of Palladium in a Perovskite

We demonstrate using a combination of X-ray and neutron diffraction and X-ray photoelectron spectroscopy that Pd2+ ions can be substituted for Ce in perovskite BaCeO3 and that, under oxidizing conditions, BaCe1-xPdxO3-δ (0 ≤ x ≤ 0.1) compositions can be prepared. Neutron diffraction has helped verify that δ ≈ x, implying that Ce4+ ions are substituted by Pd2+ and that a vacancy is concurrently created on the oxygen sublattice. The structure of the host compound and models for Pd substitution have also been studied using density functional theory, which has provided a detailed local description of the structure. The Pd2+-containing perovskite phases extrude elemental face-centered cubic palladium when heated in a reducing atmosphere. This elemental palladium is re-absorbed as ions into the perovskite lattice upon heating in flowing oxygen. Evidence for such cyclable ingress and egress of palladium under redox conditions is presented. A curious morphological change that results from the redox cycling of BaC...
Palladium-Catalyzed Intermolecular α-Arylation of Zinc Amide Enolates under Mild Conditions

The intermolecular α-arylation and vinylation of amides by palladium-catalyzed coupling of aryl bromides and vinyl bromides with zinc enolates of amides is reported. Reactions of three different types of zinc enolates have been developed. The reactions of aryl halides occur in high yields with isolated Reformatsky reagents generated from α-bromo amides, with Reformatsky reagents generated in situ from α-bromo amides, and with zinc enolates generated by quenching lithium enolates of amides with zinc chloride. This use of zinc enolates, instead of alkali metal enolates, greatly expands the scope of amide arylation. The reactions occur at room temperature or 70 °C with bromoarenes containing cyano, nitro, ester, keto, fluoro, hydroxyl, or amino functionality and with bromopyridines. Moreover, the reaction has been developed with morpholine amides, the products of which are precursors to ketones and aldehydes. The arylation of zinc enolates of amides was conducted with catalysts bearing the hindered pentaphen...
A novel enantioselective synthetic route to omuralide analogues with the potential for species selectivity in proteasome inhibition.

The building blocks shown can be combined for an enantioselective construction of the simplified omuralide analogue 4 in nine steps, with the use of (R)-atrolactic acid as a recoverable chiral controller.
Preferential cholinergic excitation of corticopontine neurons.

KEY POINTS Phasic activation of M1 muscarinic receptors generates transient inhibition followed by longer lasting excitation in neocortical pyramidal neurons. Corticopontine neurons in the mouse prefrontal cortex exhibit weaker cholinergic inhibition, but more robust and longer lasting excitation, than neighbouring callosal projection neurons. Optogenetic release of endogenous ACh in response to single flashes of light (5 ms) preferentially enhances the excitability of corticopontine neurons for many tens of seconds. Cholinergic excitation of corticopontine neurons involves at least three ionic mechanisms: suppression of KV 7 currents, activation of the calcium-dependent non-specific cation conductance underlying afterdepolarizations, and activation of what appears to be a calcium-sensitive but calcium-permeable non-specific cation conductance. Preferential cholinergic excitation of prefrontal corticopontine neurons may facilitate top-down attentional processes and behaviours. ABSTRACT Pyramidal neurons in layer 5 of the neocortex comprise two broad classes of projection neurons: corticofugal neurons, including corticopontine (CPn) neurons, and intratelencephalic neurons, including commissural/callosal (COM) neurons. These non-overlapping neuron subpopulations represent discrete cortical output channels contributing to perception, decision making and behaviour. CPn and COM neurons have distinct morphological and physiological characteristics, and divergent responses to modulatory transmitters such as serotonin and acetylcholine (ACh). To better understand how ACh regulates cortical output, in slices of mouse prefrontal cortex (PFC) we compared the responsivity of CPn and COM neurons to transient exposure to exogenous or endogenous ACh. In both neuron subtypes, exogenous ACh generated qualitatively similar biphasic responses in which brief hyperpolarization was followed by longer lasting enhancement of excitability. However, cholinergic inhibition was more pronounced in COM neurons, while excitatory responses were larger and longer lasting in CPn neurons. Similarly, optically triggered release of endogenous ACh from cholinergic terminals preferentially and persistently (for ∼40 s) enhanced the excitability of CPn neurons, but had little impact on COM neurons. Cholinergic excitation of CPn neurons involved at least three distinct ionic mechanisms: suppression of KV 7 channels (the 'M-current'), activation of the calcium-dependent non-specific cation conductance underlying afterdepolarizations, and activation of what appears to be a calcium-sensitive but calcium-permeable non-specific cation conductance. Our findings demonstrate projection-specific selectivity in cholinergic signalling in the PFC, and suggest that transient release of ACh during behaviour will preferentially promote corticofugal output.
Stereoselective synthesis of N-protected pyrrolidines via Pd-catalyzed reactions of γ-(N-acylamino) alkenes and γ-(N-Boc-amino) alkenes with aryl bromides

Abstract The stereoselective synthesis of N-acyl- and N-Boc-protected pyrrolidines via Pd-catalyzed reactions of γ-(N-acylamino) alkenes and γ-(N-Boc-amino) alkenes with aryl bromides is described. These reactions effect formation of two bonds in a single operation and proceed with generally high levels of diastereoselectivity. In contrast to previously described reactions of γ-(N-arylamino) alkenes, these transformations proceed in high yield and high regioselectivity with both electron-rich and electron-deficient aryl bromides as well as vinyl bromide substrates.
Redox Chemistry of Cu/ZSM-5

Motivated by the unique catalytic activity of Cu/ZSM-5 in the decomposition of NO to N2 + O2, the redox chemistry of Cu in zeolite ZSM-5 has been studied using FTIR, TPR, EPR, and EXAFS. Isolated ions, Cu2+, oxocations, [Cu−O−Cu]2+, and oxide particles have been identified. Their relative abundances depend on the overall Cu loading, the pH during ion exchange, and the gas atmosphere. Oxocations are only detected at Cu exchange levels exceeding 40%; their concentration is higher in high-pH preparations favoring hydrolysis. Oxocations are reduced by CO and NO at room temperature; they act as catalytic sites for the disproportionation of NO into N2O + NO2. CuO particles are detected in all samples; at elevated temperature they decompose in He to Cu2O. In FTIR Cu+ is detected using CO or NO as a probe. Flowing H2 reduces Cu2+ ions; the first detectable product is Cu+ because Cu0 is thermodynamically unstable in the presence of Cu2+. After all Cu2+ is used up Cu0 is detected. In CO only oxide particles and oxo...
Total synthesis of the marine cytotoxic caulibugulones A–D

Abstract We report the first total synthesis of the cytotoxic marine alkaloids caulibugulone A–D. This synthesis confirmed the assigned structures and provided sufficient material for further biological testing.
Enhancement of N2O4 on Porous Glass at Room Temperature: A Key Intermediate in the Heterogeneous Hydrolysis of NO2?

The heterogeneous hydrolysis of NO{sub 2} at surfaces in the atmosphere is believed to be a significant source of HONO, a key OH precursor in urban areas. However, the mechanism of this reaction is not known. The uptake of 2.9 Torr of NO{sub 2} in N{sub 2} at a total pressure of 508 Torr on a porous glass surface with varying amounts of surface-adsorbed water was studied using FTIR at 294 K. The ratio of N{sub 2}O{sub 4} to NO{sub 2} was enhanced on the glass surface relative to the gas phase. On a relatively dry surface, the formation of surface-adsorbed HNO{sub 3} was observed over a period of {approximately}20 h, likely due to the reaction with small amounts of water on the surface. Gas-phase NO and N{sub 2}O were also generated. When larger amounts of water were initially present on the surface, surface-adsorbed HNO{sub 3} was formed immediately, as well as gas-phase NO, N{sub 2}O, and HONO. Although the NO{sub 2} concentrations used in the present studies are much larger than those found in the atmosphere, this work suggests that N{sub 2}O{sub 4} should be considered as a key intermediate in the heterogeneous hydrolysis of NO{sub 2} to formmore » HONO.« less
Synthesis of diazeniumdiolates from the reactions of nitric oxide with enolates.

Reactions of nitric oxide with enolates derived from aliphatic methyl ketones containing α-methylene or α-methine groups and with enolates derived from α,α‘-dimethylene or α,α‘-dimethine ketones yi...
Scandium triflate as an efficient and useful catalyst for the synthesis of β-amino alcohols by regioselective ring opening of epoxides with amines under solvent-free conditions

Abstract A simple and efficient method has been developed for the synthesis of β-amino alcohols by ring opening of epoxides in the presence of a catalytic amount of Sc(OTf)3 at room temperature under solvent-free conditions. The reaction works well with both aromatic and aliphatic amines. High regio-, and diastereoselectivity can be considered as a noteworthy advantage of this method.
E-selective isomerization of stilbenes and stilbenoids through reversible hydroboration

Abstract Hydroboration of a mixture of E and Z stilbenes and stilbenoids is followed by an elimination reaction to yield the E isomer with high stereoselectivity. The reaction tolerates aromatic substituents with varying stereoelectronic properties, occurs in one pot, and requires only commercially available reagents. An illustration of the isomerization reaction in a synthesis of resveratrol, a biologically active antioxidant, is presented.
Diastereoselective Rh-Mediated Construction of 2,3,5-Trisubstituted Tetrahydrofurans

Dirhodium(II) carboxylate catalyzed cyclization of a series of γ-alkoxy-α-diazo esters 1 has been shown to proceed with substantial diastereoselectivity, producing the 2,3,5-trisubstituted tetrahydrofurans 2 and 3. The diastereoselectivity of the cyclization improved as the electron-withdrawing ability of the substituent R increased. A mechanistic hypothesis is presented.
A classification of primitive permutation groups with finite stabilizers

Abstract We classify all infinite primitive permutation groups possessing a finite point stabilizer, thus extending the seminal Aschbacher–O'Nan–Scott Theorem to all primitive permutation groups with finite point stabilizers.
End-to-end training approaches for discriminative segmental models

Recent work on discriminative segmental models has shown that they can achieve competitive speech recognition performance, using features based on deep neural frame classifiers. However, segmental models can be more challenging to train than standard frame-based approaches. While some segmental models have been successfully trained end to end, there is a lack of understanding of their training under different settings and with different losses.
A case study in text mining: Textual analysis of the Territorial Papers

The Territorial Papers of the United States are a valuable and underused resource containing almost 10,000 documents written between 1789 and 1848 about the formation of new sovereign states from US territory. These communications between the federal government and frontier settlers comprise the actual discourse of the nation’s expansion over six decades. Digitizing the Territorial Papers permits the possibility of analyzing the entire corpus globally. Text mining and topic modeling methods give us a lens on the language patterns through which new state governments and the expanding nation were formed. An initial statistical analysis of the textual information provides a visualization of content, helps discern how ideals about governance emerged, and lays the foundation for developing more sophisticated hypotheses and theoretical constructs.
Variable Rate Image Compression with Recurrent Neural Networks

Abstract: A large fraction of Internet traffic is now driven by requests from mobile devices with relatively small screens and often stringent bandwidth requirements. Due to these factors, it has become the norm for modern graphics-heavy websites to transmit low-resolution, low-bytecount image previews (thumbnails) as part of the initial page load process to improve apparent page responsiveness. Increasing thumbnail compression beyond the capabilities of existing codecs is therefore a current research focus, as any byte savings will significantly enhance the experience of mobile device users. Toward this end, we propose a general framework for variable-rate image compression and a novel architecture based on convolutional and deconvolutional LSTM recurrent networks. Our models address the main issues that have prevented autoencoder neural networks from competing with existing image compression algorithms: (1) our networks only need to be trained once (not per-image), regardless of input image dimensions and the desired compression rate; (2) our networks are progressive, meaning that the more bits are sent, the more accurate the image reconstruction; and (3) the proposed architecture is at least as efficient as a standard purpose-trained autoencoder for a given number of bits. On a large-scale benchmark of 32$\times$32 thumbnails, our LSTM-based approaches provide better visual quality than (headerless) JPEG, JPEG2000 and WebP, with a storage size that is reduced by 10% or more.
Crystal Structure and Magnetic Properties of the Trilayered Perovskite Sr4Rh3O10: A New Member of the Strontium Rhodate Family

The trilayered perovskite Sr4Rh3O10 is reported for the first time. High-pressure and high-temperature heating (6 GPa and 1500 °C) brought about successful preparation of a polycrystalline sample o...
Assortment and the evolution of cooperation in a Moran process with exponential fitness

Abstract We study the evolution of cooperation in a finite population interacting according to a simple model of like-with-like assortment. Evolution proceeds as a Moran process, and payoffs from the underlying cooperator–defector game are translated to positive fitnesses by an exponential transformation. These evolutionary dynamics can arise, for example, in a nest-structured population with rare migration. The use of the exponential transformation, rather than the usual linear one, is appropriate when interactions have multiplicative fitness effects, and allows for a tractable characterisation of the effect of assortment on the evolution of cooperation. We define two senses in which a greater degree of assortment can favour the evolution of cooperation, the first stronger than the second: (i) greater assortment increases, at all population states, the probability that the number of cooperators increases, relative to the probability that the number of defectors increases; and (ii) greater assortment increases the fixation probability of cooperation, relative to that of defection. We show that, by the stronger definition, greater assortment favours the evolution of cooperation for a subset of cooperative dilemmas: prisoners' dilemmas, snowdrift games, stag-hunt games, and some prisoners' delight games. For other cooperative dilemmas, greater assortment favours cooperation by the weak definition, but not by the strong definition. We also show that increasing assortment expands the set of games in which cooperation dominates the evolutionary dynamics. Our results hold for any strength of selection.
A spectral projection preconditioner for solving ill conditioned linear systems

Abstract We present a preconditioner based on spectral projection that is combined with a deflated Krylov subspace method for solving ill conditioned linear systems of equations. Our results show that the proposed algorithm requires many fewer iterations to achieve the convergence criterion for solving an ill conditioned problem than a Krylov subspace solver. In our numerical experiments, the solution obtained by the proposed algorithm is more accurate in terms of the norm of the distance to the exact solution of the linear system of equations.
Nearly Optimal Change-Point Detection with an Application to Cybersecurity

Abstract We address the sequential change-point detection problem for the Gaussian model where baseline distribution is Gaussian with variance σ2 and mean μ such that σ2 = aμ, where a > 0 is a known constant; the change is in μ from one known value to another. First, we carry out a comparative performance analysis of four detection procedures: the Cumulative Sum (CUSUM) procedure, the Shiryaev–Roberts (SR) procedure, and two its modifications—the Shiryaev–Roberts–Pollak and Shiryaev–Roberts–r procedures. The performance is benchmarked via Pollak's maximal average delay to detection and Shiryaev's stationary average delay to detection, each subject to a fixed average run length to false alarm. The analysis shows that in practically interesting cases the accuracy of asymptotic approximations is “reasonable” to “excellent”. We also consider an application of change-point detection to cybersecurity for rapid anomaly detection in computer networks. Using real network data we show that statistically traffic's i...
Multi-Reward Reinforced Summarization with Saliency and Entailment

Abstractive text summarization is the task of compressing and rewriting a long document into a short summary while maintaining saliency, directed logical entailment, and non-redundancy. In this work, we address these three important aspects of a good summary via a reinforcement learning approach with two novel reward functions: ROUGESal and Entail, on top of a coverage-based baseline. The ROUGESal reward modifies the ROUGE metric by up-weighting the salient phrases/words detected via a keyphrase classifier. The Entail reward gives high (length-normalized) scores to logically-entailed summaries using an entailment classifier. Further, we show superior performance improvement when these rewards are combined with traditional metric (ROUGE) based rewards, via our novel and effective multi-reward approach of optimizing multiple rewards simultaneously in alternate mini-batches. Our method achieves the new state-of-the-art results on CNN/Daily Mail dataset as well as strong improvements in a test-only transfer setup on DUC-2002.
Shaping van der Waals nanoribbons via torsional constraints: Scrolls, folds and supercoils

Interplay between structure and function in atomically thin crystalline nanoribbons is sensitive to their conformations yet the ability to prescribe them is a formidable challenge. Here, we report a novel paradigm for controlled nucleation and growth of scrolled and folded shapes in finite-length nanoribbons. All-atom computations on graphene nanoribbons (GNRs) and experiments on macroscale magnetic thin films reveal that decreasing the end distance of torsionally constrained ribbons below their contour length leads to formation of these shapes. The energy partitioning between twisted and bent shapes is modified in favor of these densely packed soft conformations due to the non-local van der Waals interactions in these 2D crystals; they subvert the formation of supercoils that are seen in their natural counterparts such as DNA and filamentous proteins. The conformational phase diagram is in excellent agreement with theoretical predictions. The facile route can be readily extended for tailoring the soft conformations of crystalline nanoscale ribbons and more general self-interacting filaments.