cssi/SciSciGPT-SciSciNet huggingface dataset:
Semidefinite relaxations for certifying robustness to adversarial examples

Despite their impressive performance on diverse tasks, neural networks fail catastrophically in the presence of adversarial inputs—imperceptibly but adversarially perturbed versions of natural inputs. We have witnessed an arms race between defenders who attempt to train robust networks and attackers who try to construct adversarial examples. One promise of ending the arms race is developing certified defenses, ones which are provably robust against all attackers in some family. These certified defenses are based on convex relaxations which construct an upper bound on the worst case loss over all attackers in the family. Previous relaxations are loose on networks that are not trained against the respective relaxation. In this paper, we propose a new semidefinite relaxation for certifying robustness that applies to arbitrary ReLU networks. We show that our proposed relaxation is tighter than previous relaxations and produces meaningful robustness guarantees on three different foreign networks whose training objectives are agnostic to our proposed relaxation.
Functional architecture of low-frequency variants highlights strength of negative selection across coding and non-coding annotations

Common variant heritability has been widely reported to be concentrated in variants within cell-type-specific non-coding functional annotations, but little is known about low-frequency variant functional architectures. We partitioned the heritability of both low-frequency (0.5%≤ minor allele frequency <5%) and common (minor allele frequency ≥5%) variants in 40 UK Biobank traits across a broad set of functional annotations. We determined that non-synonymous coding variants explain 17 ± 1% of low-frequency variant heritability ( $$h_{{\mathrm{lf}}}^2$$ ) versus 2.1 ± 0.2% of common variant heritability ( $$h_{\mathrm{c}}^2$$ ). Cell-type-specific non-coding annotations that were significantly enriched for $$h_{\mathrm{c}}^2$$ of corresponding traits were similarly enriched for $$h_{{\mathrm{lf}}}^2$$ for most traits, but more enriched for brain-related annotations and traits. For example, H3K4me3 marks in brain dorsolateral prefrontal cortex explain 57 ± 12% of $$h_{{\mathrm{lf}}}^2$$ versus 12 ± 2% of $$h_{\mathrm{c}}^2$$ for neuroticism. Forward simulations confirmed that low-frequency variant enrichment depends on the mean selection coefficient of causal variants in the annotation, and can be used to predict effect size variance of causal rare variants (minor allele frequency <0.5%). The authors extend stratified linkage disequilibrium score regression to partition the heritability of both low-frequency and common variants in 40 heritable traits from the UK Biobank, providing insights into low-frequency and rare variant functional architectures.
Multi-view 3D face reconstruction with deep recurrent neural networks

Abstract Image-based 3D face reconstruction has great potential in different areas, such as facial recognition, facial analysis, and facial animation. Due to the variations in image quality, single-image-based 3D face reconstruction might not be sufficient to accurately reconstruct a 3D face. To overcome this limitation, multi-view 3D face reconstruction uses multiple images of the same subject and aggregates complementary information for better accuracy. Though appealing, there are multiple challenges in practice. Among these challenges, the most significant is the difficulty to establish coherent and accurate correspondence among a set of images, especially when these images are captured under unconstrained in-the-wild condition. This work proposes a method, Deep Recurrent 3D FAce Reconstruction (DRFAR), to solve the task of multi-view 3D face reconstruction using a subspace representation of the 3D facial shape and a deep recurrent neural network that consists of both a deep convolutional neural network (DCNN) and a recurrent neural network (RNN). The DCNN disentangles the facial identity and the facial expression components for each single image independently, while the RNN fuses identity-related features from the DCNN and aggregates the identity specific contextual information, or the identity signal, from the whole set of images to estimate the facial identity parameter, which is robust to variations in image quality and is consistent over the whole set of images. Experimental results indicate significant improvement over state-of-the-art in both the accuracy and the consistency of 3D face reconstruction. Moreover, face recognition results on IJB-A with the UR2D face recognition pipeline indicate that, compared to single-view 3D face reconstruction, the proposed multi-view 3D face reconstruction algorithm can improve the face identification accuracy of UR2D by two percentage points in Rank-1 identification rate.
A Variational Characterization of Rényi Divergences

Atar, Chowdhary, and Dupuis have recently exhibited a variational formula for exponential integrals of bounded measurable functions in terms of Renyi divergences. We show that a variational characterization of the Renyi divergences between two probability distributions on a measurable space in terms of relative entropies, when combined with the elementary variational formula for exponential integrals of bounded measurable functions in terms of relative entropy, yields the variational formula of Atar, Chowdhary, and Dupuis as a corollary. We then develop an analogous variational characterization of the Renyi divergence rates between two stationary finite state Markov chains in terms of relative entropy rates. When combined with Varadhan’s variational characterization of the spectral radius of square matrices with nonnegative entries in terms of relative entropy, this yields an analog of the variational formula of Atar, Chowdary, and Dupuis in the framework of stationary finite state Markov chains.
Open Strings On The Rindler Horizon

It has been proposed that a certain ℤN orbifold, analytically continued in N, can be used to describe the thermodynamics of Rindler space in string theory. In this paper, we attempt to implement this idea for the open-string sector. The most interesting result is that, although the orbifold is tachyonic for positive integer N, the tachyon seems to disappear after analytic continuation to the region that is appropriate for computing Tr $$ {\rho}^{\mathcal{N}} $$ , where ρ is the density matrix of Rindler space and Re $$ \mathcal{N} $$ > 1. Analytic continuation of the full orbifold conformal field theory remains a challenge, but we find some evidence that if such analytic continuation is possible, the resulting theory is a logarithmic conformal field theory, necessarily nonunitary.
Alone Together: Compositional Reasoning and Inference for Weak Isolation

Serializability is a well-understood correctness criterion that simplifies reasoning about the behavior of concurrent transactions by ensuring they are isolated from each other while they execute. However, enforcing serializable isolation comes at a steep cost in performance because it necessarily restricts opportunities to exploit concurrency even when such opportunities would not violate application-specific invariants. As a result, database systems in practice support, and often encourage, developers to implement transactions using weaker alternatives. These alternatives break the strong isolation guarantees offered by serializable transactions to permit greater concurrency. Unfortunately, the semantics of weak isolation is poorly understood, and usually explained only informally in terms of low-level implementation artifacts. Consequently, verifying high-level correctness properties in such environments remains a challenging problem. To address this issue, we present a novel program logic that enables compositional reasoning about the behavior of concurrently executing weakly-isolated transactions. Recognizing that the proof burden necessary to use this logic may dissuade application developers, we also describe an inference procedure based on this foundation that ascertains the weakest isolation level that still guarantees the safety of high-level consistency assertions associated with such transactions. The key to effective inference is the observation that weakly-isolated transactions can be viewed as functional (monadic) computations over an abstract database state, allowing us to treat their operations as state transformers over the database. This interpretation enables automated verification using off-the-shelf SMT solvers. Notably, our development is parametric over a transaction’s specific isolation semantics, allowing it to be applicable over a range of concurrency control mechanisms. Case studies and experiments on real-world applications (written in an embedded DSL in OCaml) demonstrate the utility of our approach, and provide strong evidence that automated verification of weakly-isolated transactions can be placed on the same formal footing as their strongly-isolated serializable counterparts.
Effect of dietary phosphorus intake and age on intestinal phosphorus absorption efficiency and phosphorus balance in male rats

Intestinal phosphorus absorption is an important component of whole-body phosphorus metabolism, and limiting dietary phosphorus absorption is particularly of interest as a therapeutic target in patients with chronic kidney disease to manage mineral bone disorders. Yet, mechanisms and regulation of intestinal phosphorus absorption have not been adequately studied and discrepancies in findings exist based on the absorption assessment technique used. In vitro techniques show rather consistent effects of dietary phosphorus intake level and age on intestinal sodium-dependent phosphate transport. But, the few studies that have used in vivo techniques conflict with these in vitro studies. Therefore, we aimed to investigate the effects of dietary phosphorus intake level on phosphorus absorption using the in situ ligated loop technique in three different aged rats. Male Sprague-Dawley rats (n = 72), were studied at 10-, 20-, and 30-weeks-of-age on a low (0.1%), normal (0.6%), or high (1.2%) phosphorus diet in a 3x3 factorial design (n = 8/group). Rats were fed their assigned diet for 2-weeks prior to absorption testing by jejunal ligated loop as a non-survival procedure, utilizing 33P radioisotope. Metabolic cages were used for determination of calcium and phosphorus balance over the final four days prior to sacrifice, and blood was collected at the time of sacrifice for biochemistries. Our results show that phosphorus absorption was higher in 10-week-old rats compared with 20- and 30-week-olds and this corresponded to higher gene expression of the major phosphate transporter, NaPi-2b, as well as higher whole-body phosphorus balance and net phosphorus absorption. Dietary phosphorus intake level did not affect jejunal phosphorus absorption or NaPi-2b gene expression. Our results contrast with studies utilizing in vitro techniques, but corroborate results of other rodent studies utilizing in situ or in vivo methods. Thus, there is need for additional studies that employ more physiological methods of phosphorus absorption assessment.
Origin, Composition, and Structure of the Supernumerary B Chromosome of Drosophila Melanogaster

The number of chromosomes carried by an individual species is one of its defining characteristics. Some species, however, can also carry supernumerary chromosomes referred to as B chromosomes. B chromosomes were recently identified in a laboratory stock of Drosophila melanogaster-an established model organism with a wealth of genetic and genomic resources-enabling us to subject them to extensive molecular analysis. We isolated the B chromosomes by pulsed-field gel electrophoresis and determined their composition through next-generation sequencing. Although these B chromosomes carry no known euchromatic sequence, they are rich in transposable elements and long arrays of short nucleotide repeats, the most abundant being the uncharacterized AAGAT satellite repeat. Fluorescent in situ hybridization on metaphase chromosome spreads revealed this repeat is located on chromosome 4, strongly suggesting the origin of the B chromosomes is chromosome 4 Cytological and quantitative comparisons of signal intensity between chromosome 4 and the B chromosomes supports the hypothesis that the structure of the B chromosome is an isochromosome. We also report the identification of a new B chromosome variant in a related laboratory stock. This B chromosome has a similar repeat signature as the original but is smaller and much less prevalent. We examined additional stocks with similar genotypes and did not find B chromosomes, but did find these stocks lacked the AAGAT satellite repeat. Our molecular characterization of D. melanogaster B chromosomes is the first step toward understanding how supernumerary chromosomes arise from essential chromosomes and what may be necessary for their stable inheritance.
Interference Mitigation for 5G Millimeter-Wave Communications

We present a novel ultra-wideband low-cost transmit/receive architecture with reduced power and hardware requirements, which includes interference mitigation capabilities and accommodates multiple users. Specifically, a novel encoding approach is introduced to multiplex signals across large bandwidths and achieve secure communication and interference mitigation through spread signals. In this paper, a detailed description of the proposed high data rate system architecture is presented. Simulations are also provided in the presence of high-power interferers with eight concurrent users. To assess the performance and impact of the encoding/decoding process, a noise analysis was conducted for the transmitter and receiver chains. Specifically, bit error rate curves are generated at different stages of the system. The measurements show interference margin ratios improvement by at least 16 dB.
The Practical Impossibility of Testing UBI

This chapter discusses one big difficulty with conducting experiments in Universal Basic Income (UBI): the practical impossibility of testing it under most practical circumstances and the problems created by using the Negative Income Tax as an approximation of UBI.
Control of lamellar eutectic orientation via template-directed solidification

Abstract Template-directed solidification of eutectics has shown promise in the synthesis of functional mesostructured materials. While eutectic systems form microstructures with a high degree of order, the structure can be further dictated by the template that introduces additional interfaces and modulates mass and heat transfer. In this study, AgCl-KCl lamellar eutectic was solidified within lithographically fabricated pillar templates and the results were compared with phase-field simulations. It was observed that the boundary effects from the template drive changes in the orientation of lamellae within the template. The system's selection of lamellar orientation was dictated by the minimum undercooling condition. We studied a range of ratios between the eutectic lamellar spacing and the pillar geometry, and determined the parameter space in which the template drives the eutectic to change its orientation. The ability to understand and deterministically control the orientation of a eutectic through use of a template is crucial to realization of specific eutectic mesostructures for photonic, heat-transfer, interfacial engineering, sensing, and energy storage applications.
Learning what and where to attend

Most recent gains in visual recognition have originated from the inclusion of attention mechanisms in deep convolutional networks (DCNs). Because these networks are optimized for object recognition, they learn where to attend using only a weak form of supervision derived from image class labels. Here, we demonstrate the benefit of using stronger supervisory signals by teaching DCNs to attend to image regions that humans deem important for object recognition. We first describe a large-scale online experiment (ClickMe) used to supplement ImageNet with nearly half a million human-derived "top-down" attention maps. Using human psychophysics, we confirm that the identified top-down features from ClickMe are more diagnostic than "bottom-up" saliency features for rapid image categorization. As a proof of concept, we extend a state-of-the-art attention network and demonstrate that adding ClickMe supervision significantly improves its accuracy and yields visual features that are more interpretable and more similar to those used by human observers.
Enhanced land–sea warming contrast elevates aerosol pollution in a warmer world

Many climate models simulate an increase in anthropogenic aerosol species in response to warming1, particularly over the Northern Hemisphere mid-latitudes during June, July and August. Recently, it has been argued that this increase in anthropogenic aerosols can be linked to a decrease in wet removal associated with reduced precipitation2, but the mechanisms remain uncertain. Here, using a state-of-the-art climate model (the Community Atmosphere Model version 5), we expand on this notion to demonstrate that the enhanced aerosol burden and hydrological changes are related to a robust climate change phenomenon—the land–sea warming contrast3,4. Enhanced land warming is associated with continental reductions in lower-tropospheric humidity that drive decreases in low clouds—particularly large scale (stratus) clouds—which, in turn, lead to reduced large-scale precipitation and aerosol wet removal. Idealized model simulations further show that muting the land–sea warming contrast weakens these hydrological changes, thereby suppressing the aerosol increase. Moreover, idealized simulations that only feature land warming yield enhanced continental aridity and an increase in aerosol burden. Thus, unless anthropogenic emission reductions occur, our results add confidence that a warmer world will be associated with enhanced aerosol pollution. Greater land–sea temperature contrast under anthropogenic warming will enhance aerosol concentrations, reveal model simulations, linked to reductions in large-scale cloud cover and corresponding decreases in precipitation and aerosol wet removal.
Optimal investment to enable evolutionary rescue

“Evolutionary rescue” is the potential for evolution to enable population persistence in a changing environment. Even with eventual rescue, evolutionary time lags can cause the population size to temporarily fall below a threshold susceptible to extinction. To reduce extinction risk given human-driven global change, conservation management can enhance populations through actions such as captive breeding. To quantify the optimal timing of, and indicators for engaging in, investment in temporary enhancement to enable evolutionary rescue, we construct a model of coupled demographic-genetic dynamics given a moving optimum. We assume “decelerating change”, as might be relevant to climate change, where the rate of environmental change initially exceeds a rate where evolutionary rescue is possible, but eventually slows. We analyze the optimal control path of an intervention to avoid the population size falling below a threshold susceptible to extinction, minimizing costs. We find that the optimal path of intervention initially increases as the population declines, then declines and ceases when the population growth rate becomes positive, which lags the stabilization in environmental change. In other words, the optimal strategy involves increasing investment even in the face of a declining population, and positive population growth could serve as a signal to end the intervention. In addition, a greater carrying capacity relative to the initial population size decreases the optimal intervention. Therefore, a one-time action to increase carrying capacity, such as habitat restoration, can reduce the amount and duration of longer term investment in population enhancement, even if the population is initially lower than and declining away from the new carrying capacity.
Managing the discontent of the losers

During the 1990s, social structure of accumulation (SSA) theorists identified the solidification of a neoliberal SSA that included a capital-citizen accord based on ‘managing the discontent of the ...
Artificial intelligence for pediatric ophthalmology.

Purpose of reviewDespite the impressive results of recent artificial intelligence applications to general ophthalmology, comparatively less progress has been made toward solving problems in pediatric ophthalmology using similar techniques. This article discusses the unique needs of pediatric patient
Equity Risk Premiums (ERP): Determinants, Estimation and Implications – A Post‐Crisis Update

Equity risk premiums are a central component of every risk and return model in finance and are a key input into estimating costs of equity and capital in both corporate finance and valuation. Given their importance, it is surprising how haphazard the estimation of equity risk premiums remains in practice. We begin this paper by looking at the economic determinants of equity risk premiums, including investor risk aversion, information uncertainty and perceptions of macroeconomic risk. In the standard approach to estimating equity risk premiums, historical returns are used, with the difference in annual returns on stocks versus bonds over a long time period comprising the expected risk premium. We note the limitations of this approach, even in markets like the United States, which have long periods of historical data available, and its complete failure in emerging markets, where the historical data tends to be limited and volatile. We look at two other approaches to estimating equity risk premiums - the survey approach, where investors and managers ar asked to assess the risk premium and the implied approach, where a forward-looking estimate of the premium is estimated using either current equity prices or risk premiums in non-equity markets. We also look at the relationship between the equity risk premium and risk premiums in the bond market (default spreads) and in real estate (cap rates) and how that relationship can be mined to generated expected equity risk premiums. We close the paper by examining why different approaches yield different values for the equity risk premium, and how to choose the “right” number to use in analysis. (In an addendum, we also look at equity risk premiums during the market crisis, starting on September 12, 2008 through December 31, 2008, and then track the shift the changes through September 30, 2009.)
The Persistence of Broadband User Behavior: Implications for Universal Service and Competition Policy

Abstract In several markets, firms compete not for consumer expenditure but consumer attention. We examine user priorities over the allocation of their time, and interpret that behavior in light of policy discussions over universal service, data caps, and related policy topics, such as merger analysis. Specifically, we use extensive microdata on user online choice to characterize the demand for the services offered online, which drives a household's supply of attention. Our data cover a period of time that saw the introduction of many new and notable sites and new devices on which to access them. In our analysis, we assess “how” households supply their attention along various dimensions, such as their concentration of attention across the universe of sites and the amount of attention expenditure per domain visit. Remarkably, we find no change in “how” households allocated their attention despite drastically changing where they allocated it. Moreover, conditional on total attention expenditure, demographics entirely fail to predict our key measures of attention allocation decisions. We highlight several important implications, for policy and beyond, stemming from the persistence and demographic orthogonality of our novel attention measures.
Wind-Generated Current and Phase Speed of Wind Waves

Measurements of drift were made in a wind and wave facility at different elevations below the mean water level. The drift profiles were obtained for reference wind speeds, Ur = 3.1, 5.7 and 9.6 m/sec. The measurement technique involved tracing the movement of small paper discs which were soaked in water to become neutrally buoyant at the elevation of release. A logarithmic drift profile is proposed. The water shear velocity, U*w, predicts a surface stress, TS = pw U*S, in agreement with that obtained from the wind shear velocity, Ts = Pa U*li where pa and pw refer to air and water densities, respectively. The influence of wind on phase speeds of waves was investigated by solving the first order perturbation problem of the coupled shear flows in air and water. The air velocity profile was described by a logarithmic distribution and the drift profile was described by the proposed drift profile. Adequate agreement is found between the calculated and measured phase speed using Doppler radar in the wave number range 1.9 - 10 cm-1. In the wave number range 0.05 - 0.5 cm-1, measurements of phase speeds were obtained by using two wave gages. The waves were mechanically generated without wind and the wave gages were spaced to obtain coherent signals. The wind was then allowed to blow over the waves and the distance between wave gages was increased to maintain coherence. The wave length and frequency were obtained from the distance between the gages and from the generator frequency, respectively. The measured phase speeds were found to increase with wind speed consistent with theoretical computations.
Window Based BFT Blockchain Consensus

There is surge of interest to the blockchain technology not only in the scientific community but in the business community as well. Proof of Work (PoW) and Byzantine Fault Tolerant (BFT) are the two main classes of consensus protocols that are used in the blockchain consensus layer. PoW is highly scalable but very slow with about 7 (transactions/second) performance. BFT based protocols are highly efficient but their scalability are limited to only tens of nodes. One of the main reasons for the BFT limitation is the quadratic $O(n^{2})$ communication complexity of BFT based protocols for $n$ nodes that requires $n \times n$ broadcasting. In this paper, we present the Musch protocol which is BFT based and provides communication complexity $O(fn+n)$ for $f$ failures and $n$ nodes, where $f , without compromising the latency. Hence, the performance adjusts to $f$ such that for constant $f$ the communication complexity is linear. Musch achieves this by introducing the notion of exponentially increasing windows of nodes to which complains are reported, instead of broadcasting to all the nodes. To our knowledge, this is the first BFT-based blockchain protocol which efficiently addresses simultaneously the issues of communication complexity and latency under the presence of failures.
The association between sleep duration and lipid profiles: the NHANES 2013-2014.

In the current literature, the association between sleep and different lipids is inconsistent. We aimed to assess the association of sleep with HDL cholesterol, triglyceride, and LDL cholesterol in the National Health and Nutrition Examination Survey (NHANES), 2013/2014. We included 2705 participants from NHANES, 2013/2014. Cross-sectional information was measured on sleep duration and HDL cholesterol/triglyceride/LDL cholesterol. Generalized additive models (GAM) were constructed to assess the smooth relationship between the HDL cholesterol/triglyceride/LDL cholesterol, and the sleep duration. Models were adjusted for age, sex, race, marital status, household size, sitting time and physical activity. Effective degree of freedom (EDF) value in GAM indicated the amount of non-linearity of the smooth. EDF = 1 was indicative of a linear pattern of association. A value greater than 1 denoted a more complex association between outcome and sleep duration. The highest mean HDL cholesterol level was observed in participants sleeping 8 h/day. There was a significant non-linear association between sleep duration and HDL cholesterol in unadjusted GAM (EDF = 2.58, P = 0.002) and adjusted GAM (EDF = 1.85, P = 0.003). The lowest mean triglyceride level was observed in people sleeping 6 h/day. There was a significant non-linear association between sleep duration and triglyceride in unadjusted GAM (EDF = 3.05, P = 0.02) and adjusted GAM (EDF = 1.78, P = 0.02). There was no significant non-linear association between sleep duration and LDL cholesterol in either unadjusted GAM (EDF = 1.01, P = 0.2) or adjusted GAM (EDF = 1.01, P = 0.8). Short sleep duration was associated with low HDL cholesterol/high triglyceride. Further longitudinal studies are warranted to shed extra light on this relationship.
Mannich Reaction as a Key Strategy for the Synthesis of Benzoazacrown Ethers and Benzocryptands.

A convenient method for the synthesis of mono- and polycyclic azacrown macrocycles containing aromatic fragments using the Mannich condensation of phenols and secondary diamines has been studied. This new approach allowed the synthesis of bisphenols connected by oligoazaoxaalkane units in good yields without the need to protect the phenolic OH groups. These bisphenols (13-16) were alkylated with ditosylates of polyethylene glycols to give benzoazacrown ethers 25-30. Intermediate bisphenols 13-15 were also treated with three bis(methoxymethyl)-substituted diamines to form benzoazacrowns 10-12 containing internal phenolic functions. Phenol-containing mono (11) and bicyclic (3, n = 1) compounds, which were synthesized via the Mannich aminomethylation process, were used as building blocks for construction of bi- (32) and tricyclic (33) ligands. 11 refs.
The first examples of ester enolate addition across a chiral (alkoxybenzene)–chromium complex π-bond with a remarkable degree of 1,5-asymmetric induction

Abstract The first examples are described wherein addition of an ester enolate to an alkoxy-substituted arene–chromium tricarbonyl complex, to afford a substituted cyclohexenone in high enantiomeric excess.
Synthesis of chiral cyclic β-amino ketones by Ru-catalyzed asymmetric hydrogenation

Abstract Synthesis of chiral cyclic β-amino ketones has been first reported via Ru-catalyzed asymmetric hydrogenation. High enantioselectivities were achieved by using ( S )-C 3 -TunePhos chiral ligand (up to 94% ee).
Terrestriality and bacterial transfer: a comparative study of gut microbiomes in sympatric Malagasy mammals.

The gut microbiomes of mammals appear to mirror their hosts’ phylogeny, suggesting host-driven microbial community assembly. Yet, much of this evidence stems from comparative studies of distinct wild or captive populations that lack data for disentangling the relative influences of shared phylogeny and environment. Here, we present phylogenetic and multivariate analyses of gut microbiomes from six sympatric (i.e., co-occurring) mammal species inhabiting a 1-km2 area in western Madagascar—three lemur and three non-primate species—that consider genetic, dietary, and ecological predictors of microbiome functionality and composition. Host evolutionary history, indeed, appears to shape gut microbial patterns among both closely and distantly related species. However, we also find that diet—reliance on leaves versus fruit—is the best predictor of microbiome similarity among closely related lemur species, and that host substrate use—ground versus tree—constrains horizontal transmission via incidental contact with feces, with arboreal species harboring far more distinct communities than those of their terrestrial and semi-terrestrial counterparts.
Intramolecular [3 + 2] Annulation of Olefin-Tethered Cyclopropylamines

Starting from readily available olefin-tethered tertiary aminocyclopropanes, we have developed a convenient [3 + 2] annulation reaction by means of one-electron oxidation which can be induced photochemically or chemically, followed by two sequential 5-exo radical cyclizations. The rate constants for the competing 1,5-hydrogen transfer in the β-immonium carbon radical intermediate have been estimated to fall between 1000 (6-exo) and 100 (7-exo and/or 8-endo) s-1 at room temperature.
Cs7In4Bi6: A Zintl Phase Tailored from the PbO-Type Layers of the Parent InBi Compound

The title compound was made by fusion of stoichiometric mixture of the pure elements. The structure (triclinic, P1, Z = 4, a = 10.1851(4) A, b = 10.2318(7) A, c = 27.617(2) A, α = 94.457(7)°, β = 91.462(6)°, γ = 90.214(6)°) is based on In-centered tetrahedra of bismuth sharing edges to form folded chains. The latter are linked via In−In bonds in a rather complicated three-dimensional network. The structure can be explained as being carved out from the layered PbO-type structure of the parent group III−V compound of InBi. Cs7In4Bi6is a wide band-gap semiconductor according to EHMO calculations and magnetic measurements.
Vapor Deposition of Metal Oxides and Silicates: Possible Gate Insulators for Future Microelectronics

doubling every year or two forthe past 40 years. This remarkable increase in perfor-mance has required shrinking the integrated circuitsto smaller and smaller sizes. The smallest of thedimensions in modern circuits is the thickness of thegate insulator, which electrically separates the control-ling electrode (the gate) from the controlled current inthe silicon. This gate insulator has always been madefrom silicon dioxide, which in the most advanced deviceshas been reduced to a thickness of only about 1.5 nm orabout 4 atomic layers of silicon and oxygen. Furtherreduction of this thickness would allow current to leakthrough the silicon dioxide insulator in unacceptablylarge amounts, by quantum-mechanical tunneling.
Frequency‐specific neuromodulation of local and distant connectivity in aging and episodic memory function

A growing literature has focused on the brain's ability to augment processing in local regions by recruiting distant communities of neurons in response to neural decline or insult. In particular, both younger and older adult populations recruit bilateral prefrontal cortex (PFC) as a means of compensating for increasing neural effort to maintain successful cognitive function. However, it remains unclear how local changes in neural activity affect the recruitment of this adaptive mechanism. To address this problem, we combined graph theoretical measures from functional MRI with diffusion weighted imaging and repetitive transcranial magnetic stimulation (rTMS) to resolve a central hypothesis: how do aged brains flexibly adapt to local changes in cortical activity? Specifically, we applied neuromodulation to increase or decrease local activity in a cortical region supporting successful memory encoding (left dorsolateral PFC or DLPFC) using 5 or 1 Hz rTMS, respectively. We then assessed a region's local within-module degree, or the distributed between-module degree (BMD) between distant cortical communities. We predicted that (1) local stimulation-related deficits may be counteracted by boosting BMD between bilateral PFC, and that this effect should be (2) positively correlated with structural connectivity. Both predictions were confirmed; 5 Hz rTMS increased local success-related activity and local increases in PFC connectivity, while 1 Hz rTMS decreases local activity and triggered a more distributed pattern of bilateral PFC connectivity to compensate for this local inhibitory effect. These results provide an integrated, causal explanation for the network interactions associated with successful memory encoding in older adults. Hum Brain Mapp, 2017. © 2017 Wiley Periodicals, Inc.
Free energies of hydration for organic molecules from Monte Carlo simulations

Methods for the computation of free energies of solvation are reviewed, with emphasis on aqueous systems and discrete representation of the solvent molecules in Monte Carlo (MC) or molecular dynamics simulations. Precise results for small organic solutes can now be obtained routinely by MC/free energy perturbation calculations. The average error for computed free energies of hydration is 1.0 kcal/mol with the use of partial charges for the solutes from either OPLS unitedatom potential functions or from fitting to the electrostatic potential surface from 6-31G* ab initio calculations. A less rigorous, computationally more rapid method based on linear response theory is also found to be valuable and reduces the average error for the test set of 16 solutes to 0.6 kcal/mol.
A FACILE, HIGH YIELD SYNTHESIS OF γ- AND δ-HYDROXYAMIDES

γ- and δ-Hydroxyamides can be prepared in high yields by heating a lactone with ammonia in a pressure tube. The ammonia can be removed by controlled evaporation with ice/acetone cooling.
Ba21Ge2O5H24 and Related Phases. A Corrected Structure Type and Composition for a Zintl Phase Stabilized by Hydrogen

Syntheses of the so-called “suboxide” phases Ba21T2O5 (T = Ge, Si, Ga, In, Tl) are achieved only in the presence of hydrogen. The heavy-atom structure of Ba21Ge2O5H24 at room temperature was redetermined by single-crystal X-ray diffraction and found to be primitive trigonal symmetry (P3121 (No. 152), Z = 6, a = 14.4227(5) A, c = 35.332(3) A) instead of the previously refined cubic (Fd3m) result. The change greatly improves the heavy-atom parameters. Twenty-four independent deuterium atoms have also been located by time-of-flight neutron diffraction. The structure contains Ba2+ cations, and three different types of monatomic anions, corresponding to the oxidation states (Ba+2)21(Ge-4)2(O-2)5(H-)24. The deuterium atoms occupy tetrahedral, square-pyramidal, and octahedral barium interstices while the oxide anions lie in nearly regular octahedral barium polyhedra. The germanide anions are surrounded by 12 barium atoms in a distorted icosahedral configuration. Property measurements show that Ba21Ge2O5H24 is d...
A natural language processing framework to analyse the opinions on HPV vaccination reflected in twitter over 10 years (2008 - 2017).

In this research, we developed a natural language processing (NLP) framework to investigate the opinions on HPV vaccination reflected on Twitter over a 10-year period – 2008–2017. The NLP framework...
Synthesis of novel aminothiopyran dicarboxylates

A one step synthesis of previously unknown aminothiopyran dicarboxylates from readily available starting materials is described. The yields range from 33–74%.
Solubilities of Uranium(IV) Dioxide in Magnesium Chloride, Calcium Chloride, and Aluminum Chloride Melts: A Comparative Study

High-temperature near-IR absorption spectroscopy was used to study the dissolution of UO2 in molten MgCl2, CaCl2, and AlCl3 melts. The study reveals that UO2 is most soluble in molten AlCl3, followed by the melt of MgCl2. The solubility of UO2 in molten CaCl2 is too small to be measured with optical spectroscopy. This strong dependence of the solubility on the cations of the melts was rationalized by the use of the Flood−Forland−Grjotheim thermodynamic cycle.
Asymmetric Synthesis of Serricornin via Boronic Esters

Highly stereoselective boronic ester chemistry has been used for the synthesis of (4S,6S,7S)-7-hydroxy-4,6-dimethylnonanone (1), the pheromone of the cigarette beetle. 2-Bromo-1-butene (8) was made from 1-butyne via bromoboration and protodeboronation, and was converted to 1-ethylethenylmagnesium bromide. (R,R)-1,2-Dicyclohexyl-1,2-ethanediol [“(R)-DICHED”] methylboronate was treated with (dichloromethyl)lithium to yield (R)-DICHED (S)-1-chloroethylboronate (9), which with 1-ethylethenylmagnesium bromide yielded (R)-DICHED (R)−(2-ethyl-1-methyl-2-propenyl)boronate (10). Further chain extensions with (chloromethyl)lithium, (dichloromethyl)lithium followed by methylmagnesium bromide, and (dichloromethyl)lithium followed by ethylmagnesium bromide completed assembly of the carbon skeleton. Deboronation with hydrogen peroxide yielded (3S,5S,6S)-2-ethyl-3,5-dimethylocten-6-ol (14), which with osmium tetraoxide and sodium periodate yielded 1.
A convenient route to fused 5-7-6 tricyclic ring systems

Abstract An efficient and operationally simple route to fused tricyclic 5-7-6 ring systems was achieved through a consecutive 5-exo-dig cyclization/Claisen rearrangement process. The entire sequence can be conducted in one pot without isolation of intermediates.
Development of Metallacrown Ethers: A New Class of Metal Clusters

Abstract Crown ethers have been used for over twenty years as selective binding agents for alkali metal and alkaline earth ions. Although there have been many modifications to the crown ether core, none is so dramatic as to substitute heteroatoms into the positions normally occupied by carbon atoms. In this article we describe a new class of metal clusters which incorporate trivalent metal ions and nitrogen atoms into molecules that structurally and functionally mimic the behavior of crown ethers. These metallacrown ethers can be prepared in high yield in only a couple of steps and lead to molecules that may have utility in analytical chemistry, catalysis and new polymeric materials.
Uranyl dinitrate trihydrate, UO2(NO3)2(H2O)3.

The structure of the title compound, which has been synthesized by evaporation at 294 K, consists of centrosymmetric uranyl hexagonal bipyramids that share opposite equatorial edges with two nitrate triangles, resulting in two distinct finite clusters of composition [(UO2)(H2O)2(NO3)2]. There are two unique symmetrically independent UVI positions and two unique nitrate groups.
Synthesis and applications of optically active nitroxides

Abstract This article reviews the synthesis of optically active nitroxides and their applications in enantioselective oxidations, in stereoselective carbon-oxygen bond-forming reactions, as anticancer compounds, and as spin labels.
Synthesis and antifolate activity of 2,4-diamino-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine analogues of trimetrexate and piritrexim

2,4-Diamino-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidines with di- and trimethoxyaralkyl substitution at the 6-position were synthesized from the N6-unsubstituted compound and appropriate aralkyl bromides in N,N-dimethylformamide solution containing a catalytic amount of sodium iodide. An improved method of preparation of 2,4-diamino-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine from 2-amino-6-benzyl-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4(3H)-one was also developed, in which N2 was protected by reaction with pivalic anhydride and the resulting product was subjected consecutively to reaction with 4-chlorophenylphosphorodichloridate and 1,2,4-triazole, ammonolysis to replace the 4-imidazolido group and remove the N2-pivaloyl group, and catalytic hydrogenolysis to remove the 6-benzyl group. In assays of the ability of the products to inhibit dihydrofolate reductase from Pneumocystis carinii, and Toxoplasma gondii, and rat liver the most active of the compounds tested was 2,4-diamino-6-(2′-bromo-3′,4′,5′-trimethoxybenzyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine. The concentration of this compound needed to inhibit enzyme activity by 50% was 0.51 μM against the P. carinii enzyme, 0.09 μM against the T. gondii enzyme, and 0.35 μM against the rat enzyme. Thus, there was selectivity of binding to T. gondii enzyme, but not P. carinii enzyme, relative to rat enzyme. 2′,5′-Dimethoxybenzyl analogues were less active than the corresponding 3′,4′,5′-trimethoxybenzyl analogues, and compounds with a CH2CH2 or CH2CH2CH2 bridge were less active than those with a CH2 bridge. 2,4-Diamino-6-(2′-bromo-3′,4′,5′-trimethoxybenzyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine showed greater selectivity than trimetrexate or piritrexim for the P. carinii and T. gondii enzyme, but was less selective than trimethoprim or pyrimethamine. However its molar potency against both enzymes was greater than that of trimethoprim, the antifolate most commonly used, in combination with sulfamethoxazole, for initial treatment of opportunistic P. carinii and T. gondii infections in patients with AIDS and other disorders of the immune system.
hts-nim: scripting high-performance genomic analyses.

Motivation Extracting biological insight from genomic data inevitably requires custom software. In many cases, this is accomplished with scripting languages, owing to their accessibility and brevity. Unfortunately, the ease of scripting languages typically comes at a substantial performance cost that is especially acute with the scale of modern genomics datasets. Results We present hts-nim, a high-performance library written in the Nim programming language that provides a simple, scripting-like syntax without sacrificing performance. Availability and implementation hts-nim is available at https://github.com/brentp/hts-nim and the example tools are at https://github.com/brentp/hts-nim-tools both under the MIT license.
Interstitially-stabilized cluster-based halides of the early transition metals

Abstract A large number of reduced halides of the first two groups of transition metals are obtained that are built from edge-bridged octahedral cluster units (M 6 X 12 ) but only when these contain a centered (interstitial) heteroatom Z. The third component provides not only central bonding to the M 6 X 12 cluster but also valence electrons that aid in fulfilling certain minimal electron counts necessary in clusters of these electron-poor metals. Recent results are surveyed for zirconium and the rare-earth metals (group 3 plus the lanthanides). Much of the versatility and beauty of zirconium cluster phases originate with the diverse ways for intercluster bridging by additional halide plus a choice of 15 examples of Z. Some new tunnel, perovskite derivative, and network structures, as well as bonding and electronic regularities are described for these. Rare-earth metal examples afford substantial contrasts with only a few ternary examples that contain isolated clusters, these also being hypostoichiometric with fewer than 12X per 6M. Other phases formed contain either tetrameric oligomers or infinite chains constructed from classical clusters that have been condensed through sharing of metal edges. The rare-earth element examples are noteworthy in their ability to bind 18 different Z, which include 13 of the 3d, 4d or 5d metals as the interstitial component. Some relevant properties are also described.