cssi/SciSciGPT-SciSciNet huggingface dataset:
The mediodorsal pulvinar coordinates the macaque fronto-parietal network during rhythmic spatial attention.

Spatial attention is discontinuous, sampling behaviorally relevant locations in theta-rhythmic cycles (3–6 Hz). Underlying this rhythmic sampling are intrinsic theta oscillations in frontal and parietal cortices that provide a clocking mechanism for two alternating attentional states that are associated with either engagement at the presently attended location (and enhanced perceptual sensitivity) or disengagement (and diminished perceptual sensitivity). It has remained unclear, however, how these theta-dependent states are coordinated across the large-scale network that directs spatial attention. The pulvinar is a candidate for such coordination, having been previously shown to regulate cortical activity. Here, we examined pulvino-cortical interactions during theta-rhythmic sampling by simultaneously recording from macaque frontal eye fields (FEF), lateral intraparietal area (LIP), and pulvinar. Neural activity propagated from pulvinar to cortex during periods of engagement, and from cortex to pulvinar during periods of disengagement. A rhythmic reweighting of pulvino-cortical interactions thus defines functional dissociations in the attention network. Recent evidence shows that spatial attention is discontinuous over time, sampling locations in rhythmic cycles (3–6 Hz). Here, the authors show that the pulvinar has a role in coordinating this rhythmic sampling, with neural activity propagating from pulvinar to cortex during periods of engagement.
Chapter 17 – Alternative Exit and Restructuring Strategies: Bankruptcy Reorganization and Liquidation

The focus of this chapter is on bankruptcy and liquidation as alternative restructuring or exit strategies for failing firms. Bankruptcy enables a failing firm to reorganize, while protected from its creditors, or to cease operation by selling its assets to satisfy all or a portion of the firm’s outstanding debt. How reorganization and liquidation take place both inside and outside the protection of the bankruptcy court are examined in detail. This chapter also discusses common strategic options for failing firms and how to value such firms, the current state of bankruptcy prediction models, and empirical studies of the performance of firms experiencing financial distress.
Forecasting the Impact of Connected and Automated Vehicles on Energy Use: A Microeconomic Study of Induced Travel and Energy Rebound

Abstract Connected and automated vehicles (CAVs) are expected to yield significant improvements in safety, energy efficiency, and time utilization. However, their net effect on energy and environmental outcomes is unclear. Higher fuel economy reduces the energy required per mile of travel, but it also reduces the fuel cost of travel, incentivizing more travel and causing an energy “rebound effect.” Moreover, CAVs are predicted to vastly reduce the time cost of travel, inducing further increases in travel and energy use. In this paper, we forecast the induced travel and rebound from CAVs using data on existing travel behavior. We develop a microeconomic model of vehicle miles traveled (VMT) choice under income and time constraints; then we use it to estimate elasticities of VMT demand with respect to fuel and time costs, with fuel cost data from the 2017 United States National Household Travel Survey (NHTS) and wage-derived predictions of travel time cost. Our central estimate of the combined price elasticity of VMT demand is −0.4, which differs substantially from previous estimates. We also find evidence that wealthier households have more elastic demand, and that households at all income levels are more sensitive to time costs than to fuel costs. We use our estimated elasticities to simulate VMT and energy use impacts of full, private CAV adoption under a range of possible changes to the fuel and time costs of travel. We forecast a 2–47% increase in travel demand for an average household. Our results indicate that backfire – i.e., a net rise in energy use – is a possibility, especially in higher income groups. This presents a stiff challenge to policy goals for reductions in not only energy use but also traffic congestion and local and global air pollution, as CAV use increases.
Stable Pom1 clusters form a glucose-modulated concentration gradient that regulates mitotic entry

Control of cell size requires molecular size sensors that are coupled to the cell cycle. Rod-shaped fission yeast cells divide at a threshold size partly due to Cdr2 kinase, which forms nodes at the medial cell cortex where it inhibits the Cdk1-inhibitor Wee1. Pom1 kinase phosphorylates and inhibits Cdr2, and forms cortical concentration gradients from cell poles. Pom1 inhibits Cdr2 signaling to Wee1 specifically in small cells, but the time and place of their regulatory interactions were unclear. We show that Pom1 forms stable oligomeric clusters that dynamically sample the cell cortex. Binding frequency is patterned into a concentration gradient by the polarity landmarks Tea1 and Tea4. Pom1 clusters colocalize with Cdr2 nodes, forming a glucose-modulated inhibitory threshold against node activation. Our work reveals how Pom1-Cdr2-Wee1 operates in multiprotein clusters at the cortex to promote mitotic entry at a cell size that can be modified by nutrient availability.
Learning long-range spatial dependencies with horizontal gated-recurrent units

Progress in deep learning has spawned great successes in many engineering applications. As a prime example, convolutional neural networks, a type of feedforward neural networks, are now approaching -- and sometimes even surpassing -- human accuracy on a variety of visual recognition tasks. Here, however, we show that these neural networks and their recent extensions struggle in recognition tasks where co-dependent visual features must be detected over long spatial ranges. We introduce the horizontal gated-recurrent unit (hGRU) to learn intrinsic horizontal connections -- both within and across feature columns. We demonstrate that a single hGRU layer matches or outperforms all tested feedforward hierarchical baselines including state-of-the-art architectures which have orders of magnitude more free parameters. We further discuss the biological plausibility of the hGRU in comparison to anatomical data from the visual cortex as well as human behavioral data on a classic contour detection task.
Media Composition, Microbial, Laboratory Scale

Introduction Essential Nutritional Requirements Water Energy Major Chemical Elements (C, H, N, O) Minor and Microelements (Fe, Mg, K, P, S, and others) Growth Factors Physical Parameters pH Incubation Temperature Oxidation–Reduction Potential Detoxifiers Media Design and Composition Protein Hydrolysates (Peptones) Carbon and Energy Sources Extracts Buffers Gelling Agents Media Sterilization Steam Sterilization (Autoclaving) Filter Sterilization Dry Heat Sterilization Media Storage References Keywords: agar; buffers; carbon and energy sources; detoxifiers; energy; growth factors; oxidation–reduction potential; pH; protein hydrolysates (peptones); sterilization; water
Firm Development and Bribery: An Empirical Study from Latin America

This empirical research investigated how bribery by firms influences their development. The most recent firm-level data were acquired from four Latin American countries (Argentina, Bolivia, Paraguay, and Peru) and looked into the firms’ innovation capability. A translog function was used to estimate the firms’ productivity. Bribery was defined as informal payments by firms to public officials to “get things done”. In order to mitigate the endogeneity in the estimation, an instrumental variable was used for firms’ bribery payments. Bribery was found to have a significantly negative impact on both innovation capability and productivity of the observed firms. Other firm-level characteristics, such as government relationships, industry experience, participation in the global market, and number of employees, were also closely related to firm development.
Social Media Sensing Framework for Population Health

Conducting large health population studies is expensive. For instance, collecting field information about the efficacy of health campaigns or the impact of a disease may require the involvement of many health providers over an extended period of time and sometimes may not reach the target population. In fact, due to the aforementioned difficulties, health-related population statistics may be unavailable or lag by several years. Recently, social media networks have emerged as a source of sensory data for various aspects of social behavior. This source of information is used to drive marketing campaigns, conduct threat analysis and profile groups of individuals among numerous other applications. However, these applications are usually limited to specific case studies and do not provide a systematic approach to translating social media data into knowledge. In this paper, we propose a framework that can extract knowledge from social media networks in support of large scale health studies. The framework consists of an automated workflow designed to collect data from social media platforms, filter the data based on geographical criteria, and extract information relevant to a target hypothesis. The framework is demonstrated in the case of mortality and incidence of three chronic diseases, namely asthma, cancer, and diabetes. Twitter data is extracted over the period 2010 to 2015 for each target geographical region and classified based on its relevance to each of the aforementioned diseases. Due to the large number of extracted records, a simple random sampling approach is used to support the supervised training and testing of the classifier in the framework. Despite the limited number of records used for the training of the classifiers as a result of this approach, high classification accuracies are achieved for all three diseases. While the focus of the case studies in this paper is on the three chronic diseases asthma, diabetes and cancer, the utility of the proposed framework extends to other areas in the health sector. The proposed framework can help automate data-driven hypothesis validation for social media health-related studies. This paper describes the underlying methodology as well as the limitations associated with using social media data as a sensor for trends in population health.
Growth Plate Borderline Chondrocytes Behave as Transient Mesenchymal Precursor Cells.

The growth plate provides a substantial source of mesenchymal cells in the endosteal marrow space during endochondral ossification. The current model postulates that a group of chondrocytes in the hypertrophic zone can escape from apoptosis and transform into cells that eventually become osteoblasts in an area beneath the growth plate. The growth plate is composed of cells with various morphologies; particularly at the periphery of the growth plate immediately adjacent to the perichondrium are "borderline" chondrocytes, which align perpendicularly to other chondrocytes. However, in vivo cell fates of these special chondrocytes have not been revealed. Here we show that borderline chondrocytes in growth plates behave as transient mesenchymal precursor cells for osteoblasts and marrow stromal cells. A single-cell RNA-seq analysis revealed subpopulations of Col2a1-creER-marked neonatal chondrocytes and their cell type-specific markers. A tamoxifen pulse to Pthrp-creER mice in the neonatal stage (before the resting zone was formed) preferentially marked borderline chondrocytes. Following the chase, these cells marched into the nascent marrow space, expanded in the metaphyseal marrow, and became Col(2.3 kb)-GFP+ osteoblasts and Cxcl12-GFPhigh reticular stromal "CAR" cells. Interestingly, these borderline chondrocyte-derived marrow cells were short-lived, as they were significantly reduced during adulthood. These findings demonstrate based on in vivo lineage-tracing experiments that borderline chondrocytes in the peripheral growth plate are a particularly important route for producing osteoblasts and marrow stromal cells in growing murine endochondral bones. A special microenvironment neighboring the osteogenic perichondrium might endow these chondrocytes with an enhanced potential to differentiate into marrow mesenchymal cells. © 2019 American Society for Bone and Mineral Research.
Environmental Attitudes Across Race and Ethnicity

Objectives: This article examines the degree to which environmental concerns are influenced by race and ethnicity, and particularly whether significant differences exist among people of color and whites. Our objective is to clarify this uncertainty since previous studies have been limited by the timeframe and geographic scope of their data. Methods: We analyze 15 years of nationally representative data from Gallup's General Poll Social Survey. Using a multitude of dependent variables that capture a range of environmental issues, we employ ordinal logistic regression models to understand environmental attitudes across race and ethnicity. Results: We find that people of color are more concerned than whites about matters pertaining to environmental justice, and just as concerned about problems related to traditional environmentalism. Conclusions: The results of this study contribute to our understanding of the individual‐level determinants of environmental attitudes, and provide insights into the attitudinal foundations of the modern‐day environmental justice movement.
Less “Sponsorship As Advertising” and More Sponsorship-Linked Marketing As Authentic Engagement

Sponsorship is an established marketing communications platform that takes many forms. In terms of objectives and measurement, sponsorship has functioned like advertising for decades. The current w...
Cdkn2a (Arf) loss drives NF1-associated atypical neurofibroma and malignant transformation

Plexiform neurofibroma (PN) tumors are a hallmark manifestation of neurofibromatosis type 1 (NF1) that arise in the Schwann cell (SC) lineage. NF1 is a common heritable cancer predisposition syndrome caused by germline mutations in the NF1 tumor suppressor, which encodes a GTPase-activating protein called neurofibromin that negatively regulates Ras proteins. Whereas most PN are clinically indolent, a subset progress to atypical neurofibromatous neoplasms of uncertain biologic potential (ANNUBP) and/or to malignant peripheral nerve sheath tumors (MPNSTs). In small clinical series, loss of 9p21.3, which includes the CDKN2A locus, has been associated with the genesis of ANNUBP. Here we show that the Cdkn2a alternate reading frame (Arf) serves as a gatekeeper tumor suppressor in mice that prevents PN progression by inducing senescence-mediated growth arrest in aberrantly proliferating Nf1-/- SC. Conditional ablation of Nf1 and Arf in the neural crest-derived SC lineage allows escape from senescence, resulting in tumors that accurately phenocopy human ANNUBP and progress to MPNST with high penetrance. This animal model will serve as a platform to study the clonal development of ANNUBP and MPNST and to identify new therapies to treat existing tumors and to prevent disease progression.
Gerstmann-Sträussler-Scheinker disease revisited: accumulation of covalently-linked multimers of internal prion protein fragments

Despite their phenotypic heterogeneity, most human prion diseases belong to two broadly defined groups: Creutzfeldt-Jakob disease (CJD) and Gerstmann-Straussler-Scheinker disease (GSS). While the structural characteristics of the disease-related proteinase K-resistant prion protein (resPrPD) associated with the CJD group are fairly well established, many features of GSS-associated resPrPD are unclear. Electrophoretic profiles of resPrPD associated with GSS variants typically show 6–8 kDa bands corresponding to the internal PrP fragments as well as a variable number of higher molecular weight bands, the molecular nature of which has not been investigated. Here we have performed systematic studies of purified resPrPD species extracted from GSS cases with the A117V (GSSA117V) and F198S (GSSF198S) PrP gene mutations. The combined analysis based on epitope mapping, deglycosylation treatment and direct amino acid sequencing by mass spectrometry provided a conclusive evidence that high molecular weight resPrPD species seen in electrophoretic profiles represent covalently-linked multimers of the internal ~ 7 and ~ 8 kDa fragments. This finding reveals a mechanism of resPrPD aggregate formation that has not been previously established in prion diseases.
Azabicyclo[3.3.0]octanes and 6-hydroxytetrahydroquinolines from intramolecular reactions of alkenyl(amino)carbene complexes with alkynes.

Abstract The Intramolecular reactions of alkenyl substituted amino carbene complexes with alkyne functional groups tethered through the nitrogen substituent of the carbene carbon are examined. These cyclizations were expected to occur with incorporation of CO to bicyclic nitrogen hetrocyclic compounds containing a phenol function. This was found to be the case with complexes with three-carbon spacers between the nitrogen and alkyne where 6-hydroxytetrahydroquinolines were produced. In contrast, complexes with two-carbon spacers gave 1-azabicyclo[3.3.0]octanes that resulted from cyclization without CO insertion.
Regulation of Eag by Ca2+/calmodulin controls presynaptic excitability in Drosophila

Regulation of excitability is critical to tuning the nervous system for complex behaviors. We demonstrate in this article that the EAG family of voltage-gated K+ channels exhibit conserved gating b...
How to get the most bang for your buck: the evolution and physiology of nutrition-dependent resource allocation strategies

All organisms use resources to grow, survive and reproduce. The supply of these resources varies widely across landscapes and time, imposing ultimate constraints on the maximal trait values for all...
Disentangling locus of perceptual learning in the visual hierarchy of motion processing

Visual perceptual learning (VPL) can lead to long-lasting perceptual improvements. One of the central topics in VPL studies is the locus of plasticity in the visual processing hierarchy. Here, we tackled this question in the context of motion processing. We took advantage of an established transition from component-dependent representations at the earliest level to pattern-dependent representations at the middle-level of cortical motion processing. Two groups of participants were trained on the same motion direction identification task using either grating or plaid stimuli. A set of pre- and post-training tests was used to determine the degree of learning specificity and generalizability. This approach allowed us to disentangle contributions from different levels of processing stages to behavioral improvements. We observed a complete bi-directional transfer of learning between component and pattern stimuli that moved to the same directions, indicating learning-induced plasticity associated with intermediate levels of motion processing. Moreover, we found that motion VPL is specific to the trained stimulus direction, speed, size, and contrast, diminishing the possibility of non-sensory decision-level enhancements. Taken together, these results indicate that, at least for the type of stimuli and the task used here, motion VPL most likely alters visual computation associated with signals at the middle stage of motion processing.
Enantioselective aldol reaction with bromofluoroketene silyl acetals

Abstract The aldol reaction of aldehydes with bromofluoroketene ethyl trimethylsilyl acetal in the presence of a catalytic amount of a chiral Lewis acid at −78°C provides a mixture of the corresponding syn - and anti -α-bromo-α-fluoro-β-hydroxy esters with high enantioselectivities (up to 99% ee). Reaction temperature has a great influence on the stereoselectivity. The aldol reaction at −20°C proceeds with high enantio- and diastereoselectivities to preferentially afford the anti -aldols having opposite signs of optical rotation to those at −78°C.
8-Carboxamidocyclazocine analogues: redefining the structure-activity relationships of 2,6-methano-3-benzazocines.

Abstract Unexpectedly high affinity for opioid receptors has been observed for a novel series of cyclazocine analogues where the prototypic 8-OH was replaced by a carboxamido group. For μ and κ opioid receptors, the primary carboxamido derivative of cyclazocine ((±)-15) displayed high affinity (Ki=0.41 and 0.53 nM, respectively) nearly comparable to cyclazocine. A high enantiopreference ((2R,6R,11R)-) for binding was also observed. Compound (±)-15 also displayed potent antinociception activity in mice when administered icv.
Destin: toolkit for single-cell analysis of chromatin accessibility

Summary Single-cell assay of transposase-accessible chromatin followed by sequencing (scATAC-seq) is an emerging new technology for the study of gene regulation with single-cell resolution. The data from scATAC-seq are unique-sparse, binary and highly variable even within the same cell type. As such, neither methods developed for bulk ATAC-seq nor single-cell RNA-seq data are appropriate. Here, we present Destin, a bioinformatic and statistical framework for comprehensive scATAC-seq data analysis. Destin performs cell-type clustering via weighted principle component analysis, weighting accessible chromatin regions by existing genomic annotations and publicly available regulomic datasets. The weights and additional tuning parameters are determined via model-based likelihood. We evaluated the performance of Destin using downsampled bulk ATAC-seq data of purified samples and scATAC-seq data from seven diverse experiments. Compared to existing methods, Destin was shown to outperform across all datasets and platforms. For demonstration, we further applied Destin to 2088 adult mouse forebrain cells and identified cell-type-specific association of previously reported schizophrenia GWAS loci. Availability and implementation Destin toolkit is freely available as an R package at https://github.com/urrutiag/destin. Supplementary information Supplementary data are available at Bioinformatics online.
The queen’s gut refines with age: longevity phenotypes in a social insect model

In social insects, identical genotypes can show extreme lifespan variation providing a unique perspective on age-associated microbial succession. In honey bees, short- and long-lived host phenotypes are polarized by a suite of age-associated factors including hormones, nutrition, immune senescence, and oxidative stress. Similar to other model organisms, the aging gut microbiota of short-lived (worker) honey bees accrue Proteobacteria and are depleted of Lactobacillus and Bifidobacterium, consistent with a suite of host senescence markers. In contrast, long-lived (queen) honey bees maintain youthful cellular function with much lower expression of oxidative stress genes, suggesting a very different host environment for age-associated microbial succession. We sequenced the microbiota of 63 honey bee queens exploring two chronological ages and four alimentary tract niches. To control for genetic and environmental variation, we quantified carbonyl accumulation in queen fat body tissue as a proxy for biological aging. We compared our results to the age-specific microbial succession of worker guts. Accounting for queen source variation, two or more bacterial species per niche differed significantly by queen age. Biological aging in queens was correlated with microbiota composition highlighting the relationship of microbiota with oxidative stress. Queens and workers shared many major gut bacterial species, but differ markedly in community structure and age succession. In stark contrast to aging workers, carbonyl accumulation in queens was significantly associated with increased Lactobacillus and Bifidobacterium and depletion of various Proteobacteria. We present a model system linking changes in gut microbiota to diet and longevity, two of the most confounding variables in human microbiota research. The pattern of age-associated succession in the queen microbiota is largely the reverse of that demonstrated for workers. The guts of short-lived worker phenotypes are progressively dominated by three major Proteobacteria, but these same species were sparse or significantly depleted in long-lived queen phenotypes. More broadly, age-related changes in the honey bee microbiota reflect the regulatory anatomy of reproductive host metabolism. Our synthesis suggests that the evolution of colony-level reproductive physiology formed the context for host-microbial interactions and age-related succession of honey bee microbiota.
Quantum cryptography for secure free-space communications

Quantum cryptography is an emerging technology in which two parties may simultaneously generate shared, secret cryptographic key material using the transmission of quantum states of light. The security of these transmissions is based on the inviolability of the laws of quantum mechanics and information-theoretically secure post-processing methods. An adversary can neither successfully tap the quantum transmissions, nor evade detection, owing to Heisenberg's uncertainty principle. In this paper we describe the theory of quantum cryptography, and the most recent results from our experimental free-space system with which we have demonstrated for the first time the feasibility of quantum key generation over a point-to-point outdoor atmospheric path in daylight. We achieved a transmission distance of 0.5 km, which was limited only by the length of the test range. Our results provide strong evidence that cryptographic key material could be generated on demand between a ground station and a satellite (or between two satellites), allowing a satellite to be securely re-keyed on orbit. We present a feasibility analysis of surface-to-satellite quantum key generation.
Beyond BLEU: Training Neural Machine Translation with Semantic Similarity.

While most neural machine translation (NMT)systems are still trained using maximum likelihood estimation, recent work has demonstrated that optimizing systems to directly improve evaluation metrics such as BLEU can significantly improve final translation accuracy. However, training with BLEU has some limitations: it doesn’t assign partial credit, it has a limited range of output values, and it can penalize semantically correct hypotheses if they differ lexically from the reference. In this paper, we introduce an alternative reward function for optimizing NMT systems that is based on recent work in semantic similarity. We evaluate on four disparate languages trans-lated to English, and find that training with our proposed metric results in better translations as evaluated by BLEU, semantic similarity, and human evaluation, and also that the optimization procedure converges faster. Analysis suggests that this is because the proposed metric is more conducive to optimization, assigning partial credit and providing more diversity in scores than BLEU
Highly efficient asymmetric organocatalytic Michael addition of α,α-disubstituted aldehydes to nitroolefins under solvent-free conditions

Abstract A chiral pyrrolide-based diamine in combination with benzoic acid has been found to be an effective organocatalyst for Michael addition of α,α-disubstituted aldehydes with nitroolefins. The reaction provided the desired Michael products possessing all-carbon quaternary center with high yields (76–98%) and high levels of enantioselectivities (up to 97% ee) under solvent-free reaction conditions. The procedure presented is simple and makes this method suitable for practical use.
Stochastic Variance-Reduced Cubic Regularization for Nonconvex Optimization

Cubic regularization (CR) is an optimization method with emerging popularity due to its capability to escape saddle points and converge to second-order stationary solutions for nonconvex optimization. However, CR encounters a high sample complexity issue for finite-sum problems with a large data size. Various inexact variants of CR have been proposed to improve the sample complexity. In this paper, we propose a stochastic variance-reduced cubic-regularization (SVRC) method under random sampling, and study its convergence guarantee as well as sample complexity. We show that the iteration complexity of SVRC for achieving a second-order stationary solution within \epsilon accuracy is O(\epsilon^{-3/2}), which matches the state-of-art result on CR types methods. Moreover, our proposed variance reduction scheme significantly reduces the per-iteration sample complexity. The resulting total Hessian sample complexity of our SVRC is O(N^{2/3} \epsilon^{-3/2}), which outperforms the state-of-art result by a factor of O(N^{2/15}). We also study our SVRC under random sampling without replacement scheme, which yields a lower per-iteration sample complexity, and hence justifies its practical applicability.
Corresponding states for mesostructure and dynamics of supercooled water

Water famously expands upon freezing, foreshadowed by a negative coefficient of expansion of the liquid at temperatures close to its freezing temperature. These behaviors, and many others, reflect the energetic preference for local tetrahedral arrangements of water molecules and entropic effects that oppose it. Here, we provide theoretical analysis of mesoscopic implications of this competition, both equilibrium and non-equilibrium, including mediation by interfaces. With general scaling arguments bolstered by simulation results, and with reduced units that elucidate corresponding states, we derive a phase diagram for bulk and confined water and water-like materials. For water itself, the corresponding states cover the temperature range of 150 K to 300 K and the pressure range of 1 bar to 2 kbar. In this regime, there are two reversible condensed phases – ice and liquid. Out of equilibrium, there is irreversible polyamorphism, i.e., more than one glass phase, reflecting dynamical arrest of coarsening ice. Temperature–time plots are derived to characterize time scales of the different phases and explain contrasting dynamical behaviors of different water-like systems.
1-Oxaspiro[4.4]nonan-6-ones. Synthetic Access via Oxonium Ion Technology, Optical Resolution, and Conversion into Enantiopure Spirocyclic α,β-Butenolides

A general approach to the synthesis of enantiomerically pure spirocyclic α,β-butenolides is presented where the fundamental framework is rapidly elaborated by acid- or bromonium ion-induced rearrangement of the carbinol derived by addition of 2-lithio-4,5-dihydrofuran to cyclobutanone. Subsequent resolution of the resulting ketones by either sulfoximine or mandelate acetal technology has been applied effectively. The availability of these building blocks makes possible in turn the acquisition of the enantiomers of dihydrofurans typified by 17, 35, and 38 and lactones such as 25 and 31, as well as the targeted title compounds. Complementary reductions of the early intermediates provide the added advantage that the α- and β-stereoisomeric carbinol series can be obtained on demand. These capabilities have been coordinated to allow the crafting of any member of the series in relatively few steps.
REACTIONS OF GAS PHASE TRANSITION METAL ATOMS WITH SMALL HYDROCARBONS

We compare the chemistry of gas phase transition metal atoms with alkanes and alkenes, surveying the different charge states M, M + , and M 2+ . The monopositive cations are highly reactive, often dehydrogenating or demethanating linear alkanes in exothermic reactions at room temperature. A unified mechanism for such reactions is suggested. The dipositive cations abstract electrons or hydride anions from alkanes if the radii of long-range curve crossings permit. If not, M 2+ can approach the hydrocarbon to close range, and the same kinds of H 2 and CH 4 elimination reactions occur as observed in M + . The neutral atoms are inert to alkanes, but Sc, Ti, V, Ni, Zr, and Mo react with alkenes. The available evidence suggests that for M, M + , and M 2+ , the 4d and 5d metals are more reactive with hydrocarbons than the 3d metals. In all cases, the complicated interplay of the energetics of low-lying metal states of different electron spin and electron configuration; the size of valence d and s orbitals; and the character of long-range forces determines chemical reactivity in ways we are beginning to understand.
Effects of substituent and catalyst on the intramolecular Povarov reaction—synthesis of chromenonaphthyridines

Abstract 2-( N -Alkenyl- N -aryl)aminochromone-3-carbaldehyde undergoes intramolecular Povarov reaction with aromatic amines in the presence of Ph 3 P·HClO 4 to produce chromenonaphthyridine. The effects of substituent and catalyst have been studied. The substituent on the alkenyl part of aminochromone controls the mode of reaction as well as the stereochemistry of the product.
A Practical Synthesis of Cycloheptane-1,3-dione

A three-step synthesis of cycloheptane-1,3-dione has been developed which avoids the use of heavy metal or explosive reagents and provides access to multigram quantities of this material.
Mapping eQTL by leveraging multiple tissues and DNA methylation

DNA methylation is an important tissue-specific epigenetic event that influences transcriptional regulation of gene expression. Differentially methylated CpG sites may act as mediators between genetic variation and gene expression, and this relationship can be exploited while mapping multi-tissue expression quantitative trait loci (eQTL). Current multi-tissue eQTL mapping techniques are limited to only exploiting gene expression patterns across multiple tissues either in a joint tissue or tissue-by-tissue frameworks. We present a new statistical approach that enables us to model the effect of germ-line variation on tissue-specific gene expression in the presence of effects due to DNA methylation. Our method efficiently models genetic and epigenetic variation to identify genomic regions of interest containing combinations of mRNA transcripts, CpG sites, and SNPs by jointly testing for genotypic effect and higher order interaction effects between genotype, methylation and tissues. We demonstrate using Monte Carlo simulations that our approach, in the presence of both genetic and DNA methylation effects, gives an improved performance (in terms of statistical power) to detect eQTLs over the current eQTL mapping approaches. When applied to an array-based dataset from 150 neuropathologically normal adult human brains, our method identifies eQTLs that were undetected using standard tissue-by-tissue or joint tissue eQTL mapping techniques. As an example, our method identifies eQTLs by leveraging methylated CpG sites in a LIM homeobox member gene (LHX9), which may have a role in the neural development. Our score test-based approach does not need parameter estimation under the alternative hypothesis. As a result, our model parameters are estimated only once for each mRNA - CpG pair. Our model specifically studies the effects of non-coding regions of DNA (in this case, CpG sites) on mapping eQTLs. However, we can easily model micro-RNAs instead of CpG sites to study the effects of post-transcriptional events in mapping eQTL. Our model’s flexible framework also allows us to investigate other genomic events such as alternative gene splicing by extending our model to include gene isoform-specific data.
Anionic ring expansion reactions of oxabicyclo[4.2.1]heptenones. An efficient entry into the carbon framework of oxygenated cembranoids

Abstract Oxabicyclo[2.2.1]heptenones undergo 2-carbon ring expansion reactions when subjected to anionic condensations and Michael acceptors. They also undergo condensation, fragmentation, and elimination reactions in their anionic couplings with aldehydes. As an outgrowth of this interesting chemistry, we have been able to access the carbon skeleton of oxygenated cembranoids by subjecting bis-activated ene-yne 39 to the enolate from oxabicyclo[2.2.1]heptenone 1 .
SUSY dark matter with non-universal gaugino masses

In this talk the authors investigate the dark matter prospects for supersymmetric models with non-universal gaugino masses. They motivate the use of non-universal gaugino masses from several directions, including problems, with the current favorite scenario, the cMSSM. They then display new corridors of parameter space that allow an acceptable dark matter relic density once gaugino mass universality is relaxed. They finish with a specific string-derived model that allows this universality relaxation and then use the dark matter constraint to make specific statements about the hidden sector of the model.
Thorium(IV)–Selenate Clusters Containing an Octanuclear Th(IV) Hydroxide/Oxide Core

Four Th(IV) hydroxide/oxide clusters have been synthesized from aqueous solution. The structures of [Th8(μ3-O)4(μ2-OH)8(H2O)15(SeO4)8·7.5H2O] (1), [Th8(μ3-O)4(μ2-OH)8(H2O)17(SeO4)8·nH2O] (2), [Th9(μ3-O)4(μ2-OH)8(H2O)21(SeO4)10] (3), and Th9(μ3-O)4(μ2-OH)8(H2O)21(SeO4)10·nH2O (4) were determined using single crystal X-ray diffraction. Each structure consists of an octanuclear core, [Th8O4(OH)8]16+, that is built from eight Th(IV) atoms (four Th in a plane and two up and two down) linked by four “inner” μ3-O and eight “outer” μ2-OH groups. Compounds 3 and 4 additionally contain mononuclear [Th(H2O)5(SeO4)4]4– units that link the octamers into an extended structure. The octanuclear units are invariably complexed by two selenate anions that sit in two cavities formed by four planar Th(IV) and four extra-planar Th(IV) atoms, thus making [Th8O4(OH)8(SeO4)2]12+ a common building block in 1–4. However, changes in hydration as well selenate coordination give rise to structural differences that are observed in the ...
ProbAnnoWeb and ProbAnnoPy: probabilistic annotation and gap-filling of metabolic reconstructions.

Summary Gap-filling is a necessary step to produce quality genome-scale metabolic reconstructions capable of flux-balance simulation. Most available gap-filling tools use an organism-agnostic approach, where reactions are selected from a database to fill gaps without consideration of the target organism. Conversely, our likelihood based gap-filling with probabilistic annotations selects candidate reactions based on a likelihood score derived specifically from the target organism's genome. Here, we present two new implementations of probabilistic annotation and likelihood based gap-filling: a web service called ProbAnnoWeb, and a standalone python package called ProbAnnoPy. Availability and implementation Our tools are available as a web service with no installation needed (ProbAnnoWeb) at probannoweb.systemsbiology.net, and as a local python package implementation (ProbAnnoPy) at github.com/PriceLab/probannopy. Contact evangelos.simeonidis@systemsbiology.org or nathan.price@systemsbiology.org. Supplementary information Supplementary data are available at Bioinformatics online.
Synthesis of tetracyclic and pentacyclic phenothiazines via benzotriazole methodology

Treatment of 10-(benzotriazol-1-yl)alkylphenothiazine with electron-rich alkenes in the presence of zinc bromide gave tetracyclic phenothiazines 4 and 9 as well as pentacyclic phenothiazines 5, which have potential use in the pharmaceutical industry.
The Human Visual Cortex Response To Melanopsin-Directed Stimulation Is Accompanied By A Distinct Perceptual Experience

The photopigment melanopsin supports reflexive visual functions in people, such as pupil constriction and circadian photoentrainment. What contribution melanopsin makes to conscious visual perception is less studied. We devised a stimulus that targeted melanopsin separately from the cones using pulsed (3-s) spectral modulations around a photopic background. Pupillometry confirmed that the melanopsin stimulus evokes a response different from that produced by cone stimulation. In each of four subjects, a functional MRI response in area V1 was found. This response scaled with melanopic contrast and was not easily explained by imprecision in the silencing of the cones. Twenty additional subjects then observed melanopsin pulses and provided a structured rating of the perceptual experience. Melanopsin stimulation was described as an unpleasant, blurry, minimal brightening that quickly faded. We conclude that isolated stimulation of melanopsin is likely associated with a response within the cortical visual pathway and with an evoked conscious percept.
The value of the equation of state of dark energy

From recent CMB and Large Scale Structure observations the value of the equation of state of dark energy, assuming it to be constant in time, is constrained to be −1.3<w<−0.7 at the 95% confidence level: consistent with dark energy being a classical vacuum term. Here, we describe two novel and independent methods, sensitive to different systematics, that give the same value for w and similar confidence regions. This suggests that systematics are not an issue in current determinations of w. The first method yields a measurement of w that relies on the minimum number of model-dependent parameters; the second method is a non-parametric measurement of the time dependence of w(z). We also present a method to statistically determine the edge of a distribution.
Microbial Metabolism of the Diterpene Sclareol: Oxidation of the A Ring by Septomyxa affinis

Microbial metabolism of the diterpene sclareol (1) was studied. Screening studies have shown a number of microorganisms capable of metabolizing 1. Preparative-scale fermentation with Septomyxa affinis ATCC 6737 has resulted in the production of three fungal metabolites that have been characterized by 2D-NMR techniques and chemical reactions. These metabolites have been identified as 8α,13β-dihydroxylabd-14-en-3-one (2), labd-14-ene-3β.8α,13β-triol (4), and labd-14-ene-2α,8α,13β-triol (6).
Rearrangement of Indolinesulfonamides to Sulfones Using Polyphosphoric Acid (PPA)

Unlike other N-alkylsulfonanilides, indolinesulfonamides hydrolyze in 98% sulfuric acid. Recent work in this laboratory has shown that rearrangement can be achieved by using polyphosphoric acid. A series of substituted indolinesulfonamides has been prepared and rearranged to their corresponding indoline arylsulfones.
Total Synthesis of Nothapodytine B and (−)-Mappicine

Concise total syntheses of naturally occurring nothapodytine B (1, mappicine ketone) and (−)-mappicine (3) are detailed. The approach is based on the implementation of a room-temperature, inverse e...
A practical new chiral controller for asymmetric Diels-Alder and alkylation reactions.

The enantiomerically pure hydroxy sulfones (+)- and (−)-2 have been prepared from 1,2-epoxycyclohexane by a simple and practical procedure. The acrylate esters of these alcohols undergo BCl3-cataly...
A Laser Flash Photolysis Study of 11-Cis-Locked Retinal Analogues

The photophysics and photochemistry of cis-locked retinal analogues have been investigated by steady-state and by picosecond and nanosecond time-resolved techniques. We have found that retinal anal...
A Ligand-Free Palladium-Catalyzed Cross-Coupling of Aryl Sulfinates with Aryl Bromides

A ligand-free Pd-catalyzed cross-coupling of aryl sulfinates with aryl bromides has been developed. A variety of aryl bromides and aryl sulfinates undergo this transformation to yield the desired biaryl in a practical and economical manner.
Synthesis and serendipity in boron chemistry: A 50 year perspective

Abstract Chance discovery is ubiquitous in the history of science, especially in areas where theory has tended to lag behind experimental findings. In fields such as organometallic and boron cluster chemistry, serendipity has been particularly important in opening new directions and shaping the evolution of these fields. In this article selected examples from the author's half century of research in borane, carborane, and metallaborane chemistry are used to illustrate the often intricate interplay between unexpected findings and targeted synthesis.
Growth of Highly Oriented Chalcocite Thin Films on Glass by Aerosol-Assisted Spray Pyrolysis Using a New Single-Source Copper Thiolate Precursor

(CuStBu)4(PMe3)2 is synthesized as the first single-source precursor for monoclinic chalcocite (α-Cu2S). Phase-pure films of copper-rich chalcocite were grown by aerosol-assisted spray pyrolysis. The chemically pure films exhibit a very strong out-of-plane orientation on glass as a result of their composition of large micrometer-sized plates.
A Novel Synthetic Route to Chiral γ-Lactams from α-Amino Acids via Rh-Catalyzed Intramolecular C−H Insertion

Highly functionalized γ-lactams are key intermediates for the synthesis of numerous biologically significant natural products. We herein described the synthesis of various chiral γ-lactams via intramolecular C−H insertion of α-diazo-α-(phenylsulfonyl)acetamides derived from α-amino acids, which possess various functional groups. The cyclizations were highly regio- and stereoselective to afford chiral γ-lactam motifs in high yields.
Covalent Guest−Framework Interactions in Heavy Metal Sodalites: Structure and Properties of Thallium and Silver Sodalite

Covalent bonds between the heavy metal cations and the aluminosilicate framework have been discovered to be the cause of distinct structural characteristics in anhydrous sodalites Ag6[AlSiO4]6 and ...
A synthesis of (−)-tashiromine and formal synthesis of (+)-tashiromine utilizing a highly enantioselective pyrrole/cobaloxime π-cation cyclization

Abstract Cyclization of (5-N-pyrrolyl-2-hydroxypentyl)cobaloxime (13) proceeds by intramolecular electrophilic aromatic substitution of a cobaloxime π-cation onto the pyrrole ring to provide 6-exo cyclization product (14) in 95% yield. This cyclization is highly enantioselective. It is applied to a synthesis of highly enantioenriched (−)-tashiromine, (−)-21, and a formal synthesis of (+)-tashiromine.
Stereoselectivity of electrophile-promoted oxacyclizations of 1,4-dihydroxy-5-alkenes to 3-hydroxytetrahydropyrans

Abstract Stereoinduction from the allylic hydroxyl group of 1,4-dihydroxy-5-alkenes has been systematically explored with various alkene substitution patterns and electrophilic reagents. For formation of erythro-diastereomers of 2-substituted 3-hydroxytetrahydropyrans, mercuric trifluoroacetate-promoted cyclizations of cis- and (Z)-alkenyldiols generally give the highest diastereoselectivities. For the corresponding 1,4-dihydroxy-5-alkyne, mercuric triflate-catalyzed cyclization followed by triethylsilane reduction affords an alternative route to the erythro-diastereomer.