cssi/SciSciGPT-SciSciNet huggingface dataset:
Context-aware Monitoring in Robotic Surgery

Robotic-assisted minimally invasive surgery (MIS) has enabled procedures with increased precision and dexterity, but surgical robots are still open loop and require surgeons to work with a tele-operation console providing only limited visual feedback. In this setting, mechanical failures, software faults, or human errors might lead to adverse events resulting in patient complications or fatalities. We argue that impending adverse events could be detected and mitigated by applying context-specific safety constraints on the motions of the robot. We present a context-aware safety monitoring system which segments a surgical task into subtasks using kinematics data and monitors safety constraints specific to each subtask. To test our hypothesis about context specificity of safety constraints, we analyze recorded demonstrations of dry-lab surgical tasks collected from the JIGSAWS database as well as from experiments we conducted on a Raven II surgical robot. Analysis of the trajectory data shows that each subtask of a given surgical procedure has consistent safety constraints across multiple demonstrations by different subjects. Our preliminary results show that violations of these safety constraints lead to unsafe events, and there is often sufficient time between the constraint violation and the safety-critical event to allow for a corrective action.
B-Script: Transcript-based B-roll Video Editing with Recommendations

In video production, inserting B-roll is a widely used technique to enrich the story and make a video more engaging. However, determining the right content and positions of B-roll and actually inserting it within the main footage can be challenging, and novice producers often struggle to get both timing and content right. We present B-Script, a system that supports B-roll video editing via interactive transcripts. B-Script has a built-in recommendation system trained on expert-annotated data, recommending users B-roll position and content. To evaluate the system, we conducted a within-subject user study with 110 participants, and compared three interface variations: a timeline-based editor, a transcript-based editor, and a transcript-based editor with recommendations. Users found it easier and were faster to insert B-roll using the transcript-based interface, and they created more engaging videos when recommendations were provided.
Trade Shocks and the Shifting Landscape of U.S. Manufacturing

Abstract Using data over more than a century, we show that shifts in the location of manufacturing industries are a domestic reflection of what the international trade literature refers to as the product cycle in a cross-country context, with industries spawning in high-wage areas with larger pools of educated workers and moving to lower-wage areas with less education as they age or become “standardized.” We exploit the China shock industries as a set of industries that were in the late-stage product cycle by 1990 and show how the activity in those industries shifted from high-innovation areas to low-education areas over the 20th century. The analysis also suggests that the resilience of local labor markets to manufacturing shocks depends on local industries’ phase in the product cycle, on local education levels, and on local manufacturing wages. The risk of unemployment and detachment from the labor force rises most when a shock hits in areas where an industry already has begun phasing out, wages are high, or education levels are low. The results are consistent with the belief that there are long-term, secular trends in U.S. industrial structure driving the movement of industries, which shocks may mitigate or accelerate.
Insider Trading: What Really Protects U.S. Investors?

I examine the ability of the U.S. investor protection regime to limit insider trading returns, absent Section 16(b) of the Securities Exchange Act of 1934 (the short-swing rule). I find that in this setting, U.S. insiders execute short-swing trades that i) beat the market by approximately 15 basis points per day and ii) systematically divest ahead of disappointing earnings announcements. These results indicate that the bright-line rule restricting short-horizon round-trip insider trading plays a substantial role in protecting outside investors from privately informed insiders in the United States.
Occupational Social Value and Returns to Long Hours

This paper examines the phenomenon of uncompensated long hours in jobs with pro‐social characteristics and presents evidence that long‐hour wage premiums and occupational social value are substitutes in compensating salaried workers who supply hours exceeding the standard working week. I show that the social value of an occupation—in particular the degree to which jobs involve helping or providing service to others—is inversely related to long‐hour pay. Allowing for heterogeneity in the degree to which workers value their job's helping orientation lets me explore how gender differences in employees’ attitudes toward pro‐social behaviour can explain some of the observed occupational sorting trends and gender differences in long‐hour compensation. Women tend to be more strongly drawn to ‘helping’ occupations and at the same time receive lower long‐hour premiums in these jobs relative to men. I offer a theoretical framework to rationalize the empirical trends.
Reducing Crime Through Environmental Design: Evidence from a Randomized Experiment of Street Lighting in New York City

This paper offers novel experimental evidence that violent crimes can be successfully reduced by changing the situational environment that potential victims and offenders face. We focus on a ubiquitous but understudied feature of the urban landscape—street lighting—and report the first experimental evidence on the effect of street lighting on crime. Through a unique public partnership in New York City, temporary street lights were randomly allocated to 40 of the city’s public housing developments. We find evidence that communities that were assigned more lighting experienced sizable reductions in nighttime outdoor index crimes. We also observe a large decline in arrests indicating that deterrence is the most likely mechanism through which the intervention reduced crime. Results suggests that street lighting, when deployed tactically, may be a means through which policymakers can control crime without widening the net of the criminal justice system.
Keeping the Joneses from getting ahead in the first place: Envy’s influence on gift giving behavior

Abstract Past research in gift giving has largely treated asymmetries between the types of gifts givers give and the ones recipients prefer to receive as unintentional errors on the part of givers. In contrast, we show that givers sometimes intentionally bypass gifts that they know will bring the most joy and happiness to their recipients. Specifically, we demonstrate that givers dislike giving gifts that compare favorably to their own possessions, because they feel that doing so would lead them to experience envy and thus become less satisfied with their own possessions. Consequently, they instead opt for other gifts that are not superior to their own possessions and thus do not negatively impact their liking of their own possessions. Critically, givers sometimes opt for these alternative gifts even in cases where they know they are less preferred by recipients. Theoretical contributions and practical implications are discussed. (144/150 words).
Does customary international tax law exist

Customary international law is law that “results from a general and consistent practice of states followed by them from a sense of legal obligation.” “International agreements create law for states parties thereto and may lead to the creation of customary international law when such agreements are intended for adherence by states generally and are in fact widely accepted.” Does customary international law (CIL) exist in tax? There are over 3,000 bilateral tax treaties, and they are about 80% identical to each other, but do they create CIL that binds in the absence of a binding treaty, like for example the Vienna Convention on the Law of Treaties binds the US, which has not ratified it? This chapter will argue that the answer is yes, using four examples: jurisdiction to tax, the permanent establishment (PE) threshold, the arm’s length standard, and non-discrimination.
Adding duration-based quality labels to learning events for improved description of students’ online learning behavior

Many existing studies analyzing log data from online learning platforms model events such as accessing a webpage or problem solving as simple binary states. In this study, we combine quality information inferred from the duration of each event with the conventional binary states, distinguishing abnormally brief events from normal or extra-long events. The new event records, obtained from students’ interaction with 10 online learning modules, can be seen as a special form of language, with each “word” describing a student’s state of interaction with one learning module, and each “sentence” capturing the interaction with the entire sequence. We used second order Markov chains to learn the patterns of this new “language,” with each chain using the interaction states on two given modules to indicate the interaction states on the following two modules. By visualizing the Markov chains that lead to interaction states associated with either disengagement or high levels of engagement, we observed that: 1) disengagement occurs more frequently towards the end of the 10 module sequence; 2) interaction states associated with the highest level of learning effort rarely leads to disengaged states; and 3) states containing brief learning events frequently lead to disengaged states. One advantage of our approach is that it can be applied to log data with relatively small numbers of events, which is common for many online learning systems in college level STEM disciplines. Combining quality information with event logs is a simple attempt at incorporating students’ internal condition into learning analytics.
Total synthesis of (+)-ambruticin S

A convergent total synthesis of the novel antifungal agent ambruticin S (1) has been completed from the assembly of intermediates 18, 33 and 52 that served as the respective A-, B-, and C-ring precursors. The first generation approach to a potential A-ring intermediate eventuated in the synthesis of 9a via a route that featured oxidation of the dihydroxy furan 2 and elaboration of the dihydropyranone 3 derived therefrom. Although 9a served as a precursor of 31E to complete a formal synthesis of 1, there were several inefficiencies associated with the preparation of 9a. A more expedient and efficient route to an A-ring subunit was devised that commenced with the carbohydrate-derived bisacetonide aldehyde 10 and produced 18 in five steps and 46% overall yield. The synthesis of the cyclopropyl sulfone 33 was initiated with the enantioselective cyclopropanation of 19 catalyzed by Rh2[5(S)-MEPY]4. Ring opening of the resultant lactone 20 followed by a series of refunctionalizations gave 33 in a total of seven steps and 46% yield from 19. Coupling of the A- and B-ring precursors 18 and 33 was then achieved via a modified Julia coupling followed by deprotection and oxidation to furnish the key intermediate 35. The dihydropyran core of the C-ring subunit precursor 49 was formed from the ring closing metathesis of the diene 48, which was prepared in three steps from the known epoxide 45, followed by oxidation. A chelation-controlled addition to the methyl ketone 49 set the stage for a stereoselective [2,3]-Wittig rearrangement that delivered the alcohol 51 that was then transformed in two steps to the sulfone 52. A traditional Julia coupling of 52 and 35 proceeded with excellent stereoselectivity, and subsequent removal of the various protecting groups gave ambruticin S (1). The longest linear sequence was 13 steps and proceeded in 4.3% overall yield.
Oncogene mRNA imaging with 99mTc-chelator-PNA-peptides

[99mTc]PNA-peptide conjugates capable of binding to IGF1 receptors will be synthesized. Specificity of their uptake and hybridization to mRNA in normal epithelial human cells compared to human breast cancer cells will be studied.
Synthesis of chiral N-aryl pyrrolidinones via a palladium-catalyzed cross-coupling reaction

The direct synthesis of non-racemic N-aryl pyrrolidinones through the application of the Buchwald/Hartwig aryl amination reaction is reported. These reactions proceed in generally good yield, with a variety of electron deficient aryl bromides and with retention of stereochemical purity.
Precision inhibitory stimulation of individual-specific cortical hubs disrupts information processing in humans

Noninvasive brain stimulation (NIBS) is a promising treatment for psychiatric and neurologic conditions, but outcomes are variable across treated individuals. In principle, precise targeting of individual-specific features of functional brain networks could improve the efficacy of NIBS interventions. Network theory predicts that the role of a node in a network can be inferred from its connections; as such, we hypothesized that targeting individual-specific "hub" brain areas with NIBS should impact cognition more than nonhub brain areas. Here, we first demonstrate that the spatial positioning of hubs is variable across individuals but reproducible within individuals upon repeated imaging. We then tested our hypothesis in healthy individuals using a prospective, within-subject, double-blind design. Inhibition of a hub with continuous theta burst stimulation disrupted information processing during working-memory more than inhibition of a nonhub area, despite targets being separated by only a few centimeters on the right middle frontal gyrus of each subject. Based upon these findings, we conclude that individual-specific brain network features are functionally relevant and could leveraged as stimulation sites in future NIBS interventions.
Biphenyl- and fluorenyl-based potential molecular electronic devices

Abstract New potential molecular electronics devices have been synthesized based on our knowledge of systems that we previously studied. Research has shown that simple molecular systems demonstrate negative differential resistance (NDR) and memory characteristics. The new molecules rely primarily on the redox properties of the compounds to improve upon the solid-state characteristics already observed. Electrochemical tests have been performed in order to evaluate the redox properties with the hope that the electrochemical results can be used as a predictive tool to evaluate the usefulness of those compounds in device configurations.
Electron paramagnetic resonance studies of low-spin d5 transition metal complexes

Abstract A discussion of the connection between EPR parameters and the electronic structures of mono-nuclear low-spin d 5 complexes, including systems with orbitally degenerate ground states which undergo Jahn-Teller distortions. EPR experimental results are critically surveyed for complexes of Ti(—I), V(0), Cr(I), Mn(II), Fe(III), Co(IV), and their heavier congeners. A review with 426 references.
Thermodynamic equilibration of dihydropyridone enolates: application to the total synthesis of (+/-)-epiuleine

Abstract Following 1,4-reduction of 2-substituted dihydropyridones ( 1 ), the requisite ‘kinetic’ enolate can be isomerized upon warming to allow the isolation of the thermodynamic enolate as its vinyl triflate ( 3 ). This enolate interconversion is dependent on the dihydropyridone C-2 substituent and can be interpreted in terms of conformational analysis. This novel scaffold ( 3 ) opens another avenue for the strategic deployment of dihydropyridones into both natural product synthesis and drug discovery. To this end, this method is highlighted by its use as a key step in a total synthesis of (+/−) epiuleine ( 14 ).
Small Silver Clusters in Smectite Clay Interlayers

Electron spin resonance (ESR) and electron spin echo modulation (ESEM) spectroscopies have been used to characterize small paramagnetic Ag clusters and their precursors, generated in the interlayer regions of montmorillonite, hectorite, and saponite smectite clays. Samples of clays, ion exchanged with Ag+ and solvated with water or methanol, were γ-irradiated at 77 K and monitored as the temperature was increased. No evidence for cluster formation was found in hydrated clays. However, when solvated with methanol, all three clays are able to stabilize Ag32+ and Ag43+ in interlayer sites. Differences in the behavior of the three clays were observed, particularly in their abilities to stabilize Ag0 centers formed at 77 K. Montmorillonite is able to stabilize weakly coordinated Ag0 even at room temperature, whereas Ag0 is unstable above 200 K in the other two clays. Differences are explained in terms of the structures of the clays.
Petromyzonin, a hexahydrophenanthrene sulfate isolated from the larval sea lamprey (Petromyzon marinus L.).

A new hexahydrophenanthrene sulfate was identified from water conditioned with sea lamprey larvae (Petromyzon marinus) and named petromyzonin. Its structure was unequivocally elucidated on the basi...
Efficient formation of 4,6-disubstituted pyrrolo[2,3-d]pyrimidines: a novel route to TWS119, a glycogen synthase kinase-3β inhibitor

Abstract A concise synthesis of 4,6-disubstituted pyrrolo[2,3- d ]pyrimidines is described. The key step involves the formation of an ether or thioether linkage along with concurrent ring closure in one-pot to yield the desired product in only two steps from a common intermediate. The reaction is chemoselective to incorporate phenol, thiophenol, and thiol. This method enabled efficient production of TWS119, a glycogen synthase kinase-3β inhibitor.
Lobocyclamide B from Lyngbya confervoides. Configuration and Asymmetric Synthesis of β-Hydroxy-α-amino Acids by (−)-Sparteine-Mediated Aldol Addition

[reaction: see text] Lobocyclamide B, a cyclododecapeptide containing five beta-hydroxy-alpha-amino acid residues, was isolated from Lyngbya confervoides. This is the first reported occurrence of gamma-hydroxythreonine in a natural peptide. Optically active beta-hydroxy-alpha-amino acids required for configurational analysis of the title compound were prepared using a novel (-)-sparteine-mediated asymmetric aldol addition of N-(diphenylmethylene)glycine tert-butyl ester to aldehydes. The method is general for aliphatic and aryl aldehydes and notable for operational simplicity.
A NEW SPIROCYCLIC SYSTEM : SYNTHESIS OF A SILASPIROTROPYLIDENE

A silaspirotropylidene, 5, has been obtained from the reaction of the lithium salt of tetramethylsilole dianion (3) with 2 equiv of diphenylcyclopropenone, followed by quenching with Me3SiCl. The X-ray crystal structure of 5 indicates that the five-membered ring is planar and the silepine ring adopts a boat conformation.
How much do investors trade because of name/ticker confusion?

Abstract We conduct a search for pairs of companies with similar names/ticker symbols. Between 12% and 25% of such pairs exhibit co-movements in trading turnover, which we attribute to investor confusion. We estimate that trades made by mistake contributed to 5% of the trading turnover. The three-hour CARs for the company chosen by mistake around the time intervals with extreme returns for the paired company are 0.5%. The confusion is highest for large companies and around time intervals with high turnover. We show that when the cause of confusion disappears, the co-movement in turnover also disappears.
MELD: Mixed effects for large datasets

Mixed effects models provide significant advantages in sensitivity and flexibility over typical statistical approaches to neural data analysis, but mass univariate application of mixed effects models to large neural datasets is computationally intensive. Threshold free cluster enhancement also provides a significant increase in sensitivity, but requires computationally-intensive permutation-based significance testing. Not surprisingly, the combination of mixed effects models with threshold free cluster enhancement and nonparametric permutation-based significance testing is currently completely impractical. With mixed effects for large datasets (MELD) we circumvent this impasse by means of a singular value decomposition to reduce the dimensionality of neural data while maximizing signal. Singular value decompositions become unstable when there are large numbers of noise features, so we precede it with a bootstrap-based feature selection step employing threshold free cluster enhancement to identify stable features across subjects. By projecting the dependent data into the reduced space of the singular value decomposition we gain the power of a multivariate approach and we can greatly reduce the number of mixed effects models that need to be run, making it feasible to use permutation testing to determine feature level significance. Due to these innovations, MELD is much faster than an element-wise mixed effects analysis, and on simulated data MELD was more sensitive than standard techniques, such as element-wise t-tests combined with threshold-free cluster enhancement. When evaluated on an EEG dataset, MELD identified more significant features than the t-tests with threshold free cluster enhancement in a comparable amount of time.
Enantioselective synthesis of protected forms of (3R,5R)-5-hydroxypiperazic acid useful for synthesis

Abstract Protected versions of (3R,5R)-5-hydroxypiperazic acid were synthesized enantioselectively in two novel ways. The first derives its chirality from D-glutamic acid while the second uses an Evans amination and a diastereoselective bromolactonization to establish the two chiral centers. Given that this amino acid is a component of several depsipeptides, these two routes enable the synthesis of multigram quantities of protected versions of 2.
Reconstructing the History of Polygenic Scores Using Coalescent Trees

Genome-wide association studies (GWAS) have revealed that many traits are highly polygenic, in that their within-population variance is governed, in part, by small-effect variants at many genetic loci. Standard population-genetic methods for inferring evolutionary history are ill-suited for polygenic traits: when there are many variants of small effect, signatures of natural selection are spread across the genome and are subtle at any one locus. In the last several years, various methods have emerged for detecting the action of natural selection on polygenic scores, sums of genotypes weighted by GWAS effect sizes. However, most existing methods do not reveal the timing or strength of selection. Here, we present a set of methods for estimating the historical time course of a population-mean polygenic score using local coalescent trees at GWAS loci. These time courses are estimated by using coalescent theory to relate the branch lengths of trees to allele-frequency change. The resulting time course can be tested for evidence of natural selection. We present theory and simulations supporting our procedures, as well as estimated time courses of polygenic scores for human height. Because of its grounding in coalescent theory, the framework presented here can be extended to a variety of demographic scenarios, and its usefulness will increase as both GWAS and ancestral-recombination-graph inference continue to progress.
SMRT genome assembly corrects reference errors, resolving the genetic basis of virulence in Mycobacterium tuberculosis

The genetic basis of virulence in Mycobacterium tuberculosis has been investigated through genome comparisons of virulent (H37Rv) and attenuated (H37Ra) sister strains. Such analysis, however, relies heavily on the accuracy of the sequences. While the H37Rv reference genome has had several corrections to date, that of H37Ra is unmodified since its original publication. Here, we report the assembly and finishing of the H37Ra genome from single-molecule, real-time (SMRT) sequencing. Our assembly reveals that the number of H37Ra-specific variants is less than half of what the Sanger-based H37Ra reference sequence indicates, undermining and, in some cases, invalidating the conclusions of several studies. PE_PPE family genes, which are intractable to commonly-used sequencing platforms because of their repetitive and GC-rich nature, are overrepresented in the set of genes in which all reported H37Ra-specific variants are contradicted. Further, one of the sequencing errors in H37Ra masks a true variant in common with the clinical strain CDC1551 which, when considered in the context of previous work, corresponds to a sequencing error in the H37Rv reference genome. Our results constrain the set of genomic differences possibly affecting virulence by more than half, which focuses laboratory investigation on pertinent targets and demonstrates the power of SMRT sequencing for producing high-quality reference genomes.
Synthesis of furan-bridged 10-membered rings through [8 + 2]-cycloaddition of dienylfurans and acetylenic esters.

The coupling of various dienylfurans with dimethyl acetylenedicarboxylate (DMAD) has been examined. In most cases this reaction proceeds via [8 + 2]-cycloaddition to afford furan-bridged 10-membered ring systems as a single diastereomer. Dienylfuran intermediates were generated using either a chromium carbene-based method or aldol-based methods. Reaction of [8 + 2]-cycloadducts with electrophilic reagents occurred selectively at the enol ether alkene.
Enantioselective reduction of aliphatic ketones using NaBH4 and TarB–NO2, a chiral boronic ester

Abstract High enantioselectivities are obtained using a tartaric acid-derived boronic ester (TarB–NO2) in combination with NaBH4 for the asymmetric reduction of aliphatic ketones. The resulting alcohols are obtained in enantiomeric excesses ranging from 56% to 94%.
Geobacter sulfurreducens Extracellular Multiheme Cytochrome PgcA Facilitates Respiration to Fe(III) Oxides But Not Electrodes.

Extracellular cytochromes are hypothesized to facilitate the final steps of electron transfer between the outer membrane of the metal-reducing bacterium Geobacter sulfurreducens and solid-phase electron acceptors such as metal oxides and electrode surfaces during the course of respiration. The triheme c-type cytochrome PgcA exists in the extracellular space of G. sulfurreducens, and is one of many multiheme c-type cytochromes known to be loosely bound to the bacterial outer surface. Deletion of pgcA using a markerless method resulted in mutants unable to transfer electrons to Fe(III) and Mn(IV) oxides; yet the same mutants maintained the ability to respire to electrode surfaces and soluble Fe(III) citrate. When expressed and purified from Shewanella oneidensis, PgcA demonstrated a primarily alpha helical structure, three bound hemes, and was processed into a shorter 41 kDa form lacking the lipodomain. Purified PgcA bound Fe(III) oxides, but not magnetite, and when PgcA was added to cell suspensions of G. sulfurreducens, PgcA accelerated Fe(III) reduction similar to addition of FMN. Addition of soluble PgcA to ∆pgcA mutants also restored Fe(III) reduction. This report highlights a distinction between proteins involved in extracellular electron transfer to metal oxides and poised electrodes, and suggests a specific role for PgcA in facilitating electron transfer at mineral surfaces.
Canvas SPW: calling de novo copy number variants in pedigrees

Motivation Whole genome sequencing is becoming a diagnostics of choice for the identification of rare inherited and de novo copy number variants in families with various pediatric and late-onset genetic diseases. However, joint variant calling in pedigrees is hampered by the complexity of consensus breakpoint alignment across samples within an arbitrary pedigree structure. Results We have developed a new tool, Canvas SPW, for the identification of inherited and de novo copy number variants from pedigree sequencing data. Canvas SPW supports a number of family structures and provides a wide range of scoring and filtering options to automate and streamline identification of de novo variants. Availability and implementation Canvas SPW is available for download from https://github.com/Illumina/canvas. Contact sivakhno@illumina.com. Supplementary information Supplementary data are available at Bioinformatics online.
Probing the Acyl Carrier Protein-Enzyme Interactions within Terminal Alkyne Biosynthetic Machinery

The alkyne functionality has attracted much interest due to its diverse chemical and biological applications. We recently elucidated an acyl carrier protein (ACP)-dependent alkyne biosynthetic pathway, however, little is known about ACP interactions with the alkyne biosynthetic enzymes, an acyl-ACP ligase (JamA) and a membrane-bound bi-functional desaturase/acetylenase (JamB). Here, we showed that JamB has a more stringent interaction with ACP than JamA. In addition, site directed mutagenesis of a non-cognate ACP significantly improved its compatibility with JamB, suggesting a possible electrostatic interaction at the ACP-JamB interface. Finally, error-prone PCR and screening of a second non-cognate ACP identified hot spots on the ACP that are important for interacting with JamB and yielded mutants which were better recognized by JamB. Our data thus not only provide insights into the ACP interactions in alkyne biosynthesis, but it also potentially aids in future combinatorial biosynthesis of alkyne-tagged metabolites for chemical and biological applications.
A caged hydrophobic inhibitor of carbonic anhydrase II.

A tight-binding, hydrophobic inhibitor of carbonic anhydrase II has been masked with a water-solubilizing, photolabile group derived from o-nitrophenylglycine. This caged inhibitor represents our first effort at the site-specific delivery of prodrugs that can be activated by light. Via this approach, we have begun to address the problems of water insolubility and systemic side effects on administration of tight-binding inhibitors of carbonic anhydrase.
Recent advances in the chemistry of carboranes and metallacarboranes

An overview of the syntheses, structures, and reactivity of the compounds formed by the incorporation of a number of d- and f-block metals into C 2 B 4 - and C 2 B 9 -carborane cages have been presented. In addition, the development of a safe, bench-scale preparation of the toxic and commercially unavailable polyhedral borane synthon, namely pentaborane(9), has also been described. Thus, this report discusses the latest developments leading to a sys- tematic synthetic approach to a number of carborane precursors and the subsequent reaction chemistry in the formation of a number of "carbons-apart" metallacarboranes.
Rapid synthesis of crystalline gallium nitride from solid precursors at atmospheric pressure

Highly crystalline hexagonal gallium nitride (GaN) can be formed in a rapid ambient pressure metathesis reaction between GaI3, Li3N, and NH4Cl. An ideal ratio of GaI3:Li3N:NH4Cl produces highly cry...
Transcriptional Burst Initiation and Polymerase Pause Release Are Key Control Points of Transcriptional Regulation.

Summary Transcriptional regulation occurs via changes to rates of different biochemical steps of transcription, but it remains unclear which rates are subject to change upon biological perturbation. Biochemical studies have suggested that stimuli predominantly affect the rates of RNA polymerase II (Pol II) recruitment and polymerase release from promoter-proximal pausing. Single-cell studies revealed that transcription occurs in discontinuous bursts, suggesting that features of such bursts like frequency and intensity could also be regulated. We combined Pol II chromatin immunoprecipitation sequencing (ChIP-seq) and single-cell transcriptional measurements to show that an independently regulated burst initiation step is required before polymerase recruitment can occur. Using a number of global and targeted transcriptional regulatory perturbations, we showed that biological perturbations regulated both burst initiation and polymerase pause release rates but seemed not to regulate polymerase recruitment rate. Our results suggest that transcriptional regulation primarily acts by changing the rates of burst initiation and polymerase pause release.
Significant shared heritability underlies suicide attempt and clinically predicted probability of attempting suicide

Suicide accounts for nearly 800,000 deaths per year worldwide with rates of both deaths and attempts rising. Family studies have estimated substantial heritability of suicidal behavior; however, collecting the sample sizes necessary for successful genetic studies has remained a challenge. We utilized two different approaches in independent datasets to characterize the contribution of common genetic variation to suicide attempt. The first is a patient reported suicide attempt phenotype asked as part of an online mental health survey taken by a subset of participants (n = 157,366) in the UK Biobank. After quality control, we leveraged a genotyped set of unrelated, white British ancestry participants including 2433 cases and 334,766 controls that included those that did not participate in the survey or were not explicitly asked about attempting suicide. The second leveraged electronic health record (EHR) data from the Vanderbilt University Medical Center (VUMC, 2.8 million patients, 3250 cases) and machine learning to derive probabilities of attempting suicide in 24,546 genotyped patients. We identified significant and comparable heritability estimates of suicide attempt from both the patient reported phenotype in the UK Biobank (h2SNP = 0.035, p = 7.12 × 10−4) and the clinically predicted phenotype from VUMC (h2SNP = 0.046, p = 1.51 × 10−2). A significant genetic overlap was demonstrated between the two measures of suicide attempt in these independent samples through polygenic risk score analysis (t = 4.02, p = 5.75 × 10−5) and genetic correlation (rg = 1.073, SE = 0.36, p = 0.003). Finally, we show significant but incomplete genetic correlation of suicide attempt with insomnia (rg = 0.34–0.81) as well as several psychiatric disorders (rg = 0.26–0.79). This work demonstrates the contribution of common genetic variation to suicide attempt. It points to a genetic underpinning to clinically predicted risk of attempting suicide that is similar to the genetic profile from a patient reported outcome. Lastly, it presents an approach for using EHR data and clinical prediction to generate quantitative measures from binary phenotypes that can improve power for genetic studies.
Palladium-Catalyzed Cross-Coupling Syntheses of Benzotriazolyl Enynes and a General Route to Enynyl Ketones and Alkynyl Ketones

A new general route to conjugated enynyl ketones was developed based on a two-step procedure. First, palladium-catalyzed cross-coupling reactions of 1-(benzotriazol-1-yl)propargyl ethyl ether (3) and vinyl triflates or vinyl bromides afforded the key intermediates [1-(benzotriazol-1-yl)-1-enynyl]methyl ethyl ethers 5a-d in good yields. Then reactions of compounds 5 with primary halides gave intermediates 8, which were hydrolyzed by dilute acid to enynyl ketones 9a-g. Similar palladium-catalyzed coupling reactions of 3 with various aryl iodides followed by an analogous sequence afforded aryl-substituted propargyl ethers 12a-d and thence alkynyl ketones 13a,b.
Asymmetric dihydroxylation catalyzed by ionic polymer-supported osmium tetroxide

Abstract Osmium tetroxide was immobilized onto a short-length PEGylated ionic polymer, which exhibited excellent catalytic performance in OsO4-catalyzed asymmetric dihydroxylation. The resulting polymer was recycled five times without any loss of yield or enantioselectivity. In addition to the immobilization of osmium, the polymer also exhibited an ability to immobilize a significant amount of chiral ligand.
Spirodiepoxide reaction with cuprates.

The first example of transition-metal-mediated transformations of spirodiepoxides and the first general method for carbon−carbon bond formation using the spirodiepoxide functional group are reporte...
The cosmic ray—X-ray connection: Effects of nonlinear shock acceleration on photon production in SNRs

Cosmic-ray production in young supernova remnant (SNR) shocks is expected to be efficient and strongly nonlinear. In nonlinear, diffusive shock acceleration, compression ratios will be higher and the shocked temperature lower than test-particle, Rankine-Hugoniot relations predict. Furthermore, the heating of the gas to X-ray emitting temperatures is strongly coupled to the acceleration of cosmic-ray electrons and ions, thus nonlinear processes which modify the shock, influence the emission over the entire band from radio to gamma-rays and may have a strong impact on X-ray line models. Here we apply an algebraic model of nonlinear acceleration, combined with SNR evolution, to model the radio and X-ray continuum of Kepler’s SNR.
Synthesis and Catalytic Activity of Cryptomelane-Type Manganese Dioxide Nanomaterials Produced by a Novel Solvent-Free Method

Cryptomelane-type K-OMS-2 nanomaterials with high surface area (156 m2/g) have been synthesized via a low-temperature solvent-free method in a very short time (1 h). Field emission scanning electron microscopy and high-resolution transmission electron microscopy images reveal that these materials have nanorod morphologies with average diameters of about 10 nm and lengths of about 50 nm. These are different from the long fiberous morphologies of OMS-2 materials made by conventional reflux or hydrothermal methods. X-ray diffraction and Brunauer−Emmett−Teller studies indicate that these materials have small crystallite sizes (∼9.8 nm) and that they are mesoporous with a uniform pore size distribution centered at 12 nm. These K-OMS-2 materials show improved catalytic activity for the oxidation of alcohols compared with the conventional K-OMS-2 materials, which may be due to their higher surface areas and novel surface properties. This fast, inexpensive, and environmentally friendly solvent-free method has the...
Heritability of the Structures and 13C Fractionation in Tomato Leaf Wax Alkanes: A Genetic Model System to Inform Paleoenvironmental Reconstructions

Leaf wax n-alkanes are broadly used to reconstruct paleoenvironmental information. However, the utility of n-alkanes as a paleoenvironmental proxy may be modulated by the extent to which biological as well as environmental factors influence the structural and isotopic variability of leaf waxes. In paleoclimate applications, there is usually an implicit assumption that most variation of leaf wax traits through a time series can be attributed to environmental change and that biological sources of variability within plant communities are small. For example, changes in hydrology affect the δ2H of waxes via rainwater and the δ13C of leaf waxes by changing plant communities. We measured the degree of genetic control over δ13C variation in leaf waxes within closely related species with an experimental greenhouse growth study. We measured the proportion of variability in structural and isotopic leaf wax traits that is attributable to genetic variation using a set of 76 introgression lines (ILs) between two interfertile Solanum (tomato) species: S. lycopersicum cv M82 (hereafter cv M82) and S. pennellii. Leaves of S. pennellii, a wild desert tomato relative, produced significantly more iso-alkanes than cv M82, a domesticated tomato cultivar adapted to water-replete conditions. We report a methylation index to summarize the ratio of branched (iso- and anteiso-) to total alkanes. Between S. pennellii and cv M82, the iso-alkanes were found to be enriched in 13C by 1.2–1.4‰ over n-alkanes. The broad-sense heritability values (H2) of leaf wax traits describe the degree to which genetic variation contributes to variation of these traits. Variation of individual carbon isotopic compositions of alkanes were of low heritability (H2 = 0.13–0.19), suggesting that most variation in δ13C of leaf waxes in this study can be attributed to environmental variance. This supports the interpretation that variation in the δ13C of wax compounds recorded in sediments reflects paleoenvironmental and vegetation changes. Average chain length (ACL) values of n-alkanes were of intermediate heritability (H2 = 0.30), suggesting that ACL values are more strongly influenced by genetic cues.
Synthesis of novel heterocyclic structures via reaction of isocyanides with S-trans-enones.

The reaction of enone 1, bearing an internal nucleophilic moiety, i.e., furan or pyrrole (X = O, NR‘), with isocyanides is presented. The formation of products resulting from the reaction of the zwitterionic intermediate 2 with a second equivalent of isocyanide prior to cyclization to give 3, as well as the direct formation of 4 from 2, is described.
Markets for Corporate Debt Securities

This paper surveys markets for corporate debt securities in the major industrial countries and the international markets. The discussion includes a comparison of the sizes of the markets for various products, as well as the key operational, institutional, and legal features of primary and secondary markets. Although there are some signs that debt markets may be emphasized in the future by some countries, it remains true that North American debt markets are the most active and liquid in the world. The international debt markets are, however, growing in importance. The paper also investigates some of the reasons for the underdevelopment of domestic bond markets and the consequences of firms shifting their debt financing needs from banks to securities markets.
Strangeness in the nucleon from a mixed action calculation

The contributions of strange quarks to the nucleon mass and the nucleon spin are investigated in a mixed action scheme employing domain wall valence quarks and quark loops on MILC asqtad dynamical fermion ensembles. Results are presented for pion masses 495 MeV and 356 MeV.
Decoding the tradeoff between encoding and retrieval to predict memory for overlapping events.

Abstract When new events overlap with past events, there is a natural tradeoff between encoding the new event and retrieving the past event. Given the ubiquity of overlap among memories, this tradeoff between memory encoding and retrieval is of central importance to computational models of episodic memory (O’Reilly & McClelland 1994; Hasselmo 2005). However, prior studies have not directly linked neural markers of encoding/retrieval tradeoffs to behavioral measures of how overlapping events are remembered. Here, by decoding patterns of scalp electroencephalography (EEG) from male and female human subjects, we show that tradeoffs between encoding and retrieval states are reflected in distributed patterns of neural activity and, critically, these neural tradeoffs predict how overlapping events will later be remembered. Namely, new events that overlapped with past events were more likely to be subsequently remembered if neural patterns were biased toward a memory encoding state–or, conversely, away from a retrieval state. Additionally, we show that neural markers of encoding vs. retrieval states are surprisingly independent from previously-described EEG predictors of subsequent memory. Instead, we demonstrate that previously-described EEG predictors of subsequent memory are better explained by task engagement than by memory encoding, per se. Collectively, our findings provide important insight into how the memory system balances memory encoding and retrieval states and, more generally, into the neural mechanisms that support successful memory formation.
A Single Dose of Dietary Nitrate Increases Maximal Knee Extensor Angular Velocity and Power in Healthy Older Men and Women.

BACKGROUND Aging results in reductions in maximal muscular strength, speed, and power, which often lead to functional limitations highly predictive of disability, institutionalization, and mortality in elderly adults. This may be partially due to reduced nitric oxide (NO) bioavailability. We, therefore, hypothesized that dietary nitrate (NO3-), a source of NO via the NO3- → nitrite (NO2-) → NO enterosalivary pathway, could increase muscle contractile function in older subjects. METHODS Twelve healthy older (age 71 ± 5 years) men and women were studied using a randomized, double-blind, placebo-controlled, crossover design. After fasting overnight, subjects were tested 2 hours after ingesting beetroot juice containing or devoid of 13.4 ± 1.6 mmol NO3-. Plasma NO3- and NO2- and breath NO were measured periodically, and muscle function was determined using isokinetic dynamometry. RESULTS N O 3 - ingestion increased (p < .001) plasma NO3-, plasma NO2-, and breath NO by 1,051% ± 433%, 138% ± 149%, and 111% ± 115%, respectively. Maximal velocity of knee extension increased (p < .01) by 10.9% ± 12.1%. Maximal knee extensor power increased (p < .05) by 4.4% ± 7.8%. CONCLUSIONS Acute dietary NO3- intake improves maximal knee extensor angular velocity and power in older individuals. These findings may have important implications for this population, in whom diminished muscle function can lead to functional limitations, dependence, and even premature death.
DeClassifier: Class-Inheritance Inference Engine for Optimized C++ Binaries

Recovering class inheritance from C++ binaries has several security benefits including in solving problems such as decompilation and program hardening. Thanks to the optimization guidelines prescribed by the C++ standard, commercial C++ binaries tend to be optimized. While state-of-the-art class inheritance inference solutions are effective in dealing with unoptimized code, their efficacy is impeded by optimization. Particularly, constructor inlining---or worse exclusion---due to optimization render class inheritance recovery challenging. Further, while modern solutions such as MARX can successfully group classes within an inheritance sub-tree, they fail to establish directionality of inheritance, which is crucial for security-related applications (e.g. decompilation). We implemented a prototype of DeClassifier using Binary Analysis Platform (BAP) and evaluated DeClassifier against 16 binaries compiled using gcc under multiple optimization settings. We show that (1) DeClassifier can recover 94.5% and 71.4% true positive directed edges in the class hierarchy tree (CHT) under O0 and O2 optimizations respectively, (2) a combination of constructor-destructor (ctor-dtor) analysis provides a substantial improvement in inheritance inference than constructor-only (ctor-only) analysis.
An upper bound for the restricted online Ramsey number

Abstract The restricted ( m , n ; N ) -online Ramsey game is a game played between two players, Builder and Painter. The game starts with N isolated vertices. Each turn Builder picks an edge to build and Painter chooses whether that edge is red or blue, and Builder aims to create a red K m or blue K n in as few turns as possible. The restricted online Ramsey number r ( m , n ; N ) is the minimum number of turns that Builder needs to guarantee her win in the restricted ( m , n ; N ) -online Ramsey game. We show that if N = r ( n , n ) , r ( n , n ; N ) ≤ N 2 − Ω ( N log N ) , motivated by a question posed by Conlon, Fox, Grinshpun and He. The equivalent game played on infinitely many vertices is called the online Ramsey game. As almost all known Builder strategies in the online Ramsey game end up reducing to the restricted setting, we expect further progress on the restricted online Ramsey game to have applications in the general case.