cssi/SciSciGPT-SciSciNet huggingface dataset:
Optimal (and benchmark-optimal) competition complexity for additive buyers over independent items

The Competition Complexity of an auction setting refers to the number of additional bidders necessary in order for the (deterministic, prior-independent, dominant strategy truthful) Vickrey-Clarke-Groves mechanism to achieve greater revenue than the (randomized, prior-dependent, Bayesian-truthful) optimal mechanism without the additional bidders. We prove that the competition complexity of n bidders with additive valuations over m independent items is at most n(ln(1+m/n)+2), and also at most 9√nm. When n ≤ m, the first bound is optimal up to constant factors, even when the items are i.i.d. and regular. When n ≥ m, the second bound is optimal for the benchmark introduced by Eden et al. up to constant factors, even when the items are i.i.d. and regular. We further show that, while the Eden et al. benchmark is not necessarily tight in the n ≥ m regime, the competition complexity of n bidders with additive valuations over even 2 i.i.d. regular items is indeed ω(1). Our main technical contribution is a reduction from analyzing the Eden et al. benchmark to proving stochastic dominance of certain random variables.
Epistemic Trajectories: Mentoring in a Game Design Practicum.

Innovative professionals rely on a specific ways of thinking to solve the nonstandard problems that come up in practice (Goodwin, Am Anthropol 96(3):606–633, 1994; Schon, The reflective practitioner: how professionals think in action, 1983; Educating the reflective practitioner: toward a new design for teaching and learning in the professions, 1987; Sullivan, Work and integrity: the crisis and promise of professionalism in America, 1995). The professions have reproductive practices for transmitting these ways of thinking, such as practica (Schon, Educating the reflective practitioner: toward a new design for teaching and learning in the professions, 1987). In this paper, we examine the learning relationship between a mentor and team of college students through an ethnographic study of a game design practicum at a European arts school. To examine the role that the mentor played in this practicum, we use two theoretical constructs. Epistemic frames—the configurations of the skills, knowledge, identities, values, and epistemologies that professionals use to think in innovative ways—provide a model for examining professional expertise (Shaffer, Comput Educ, 46(3):223–234, 2006a). Epistemic network analysis (ENA) (Shaffer et al., Int J Learn Media, 1(2):33–53, 2009) is a method for quantifying changes in epistemic frames (Shaffer, The bicycle helmets of “Amsterdam”: computer games and the problem of transfer, 2010). Our results here suggest that the mentor leads the team on a path that illuminates the nature of learning to think professionally, as well the function of a mentor in that process. We argue that the mentor, rather than providing a direct map to a professional vantage point, scaffolds aspects of the epistemic frame of game design that, in turn, aid in the development of a more professional frame. Using ENA to understand the way that mentors help coach learners to develop epistemic frames should be useful for further studies of professional education, as well as for studies of apprenticeship-based programs for youth.
Pathogen at the Gates: Human Cytomegalovirus Entry and Cell Tropism

The past few years have brought substantial progress toward understanding how human cytomegalovirus (HCMV) enters the remarkably wide spectrum of cell types and tissues that it infects. Neuropilin-2 and platelet-derived growth factor receptor alpha (PDGFRα) were identified as receptors, respectively, for the trimeric and pentameric glycoprotein H/glycoprotein L (gH/gL) complexes that in large part govern HCMV cell tropism, while CD90 and CD147 were also found to play roles during entry. X-ray crystal structures for the proximal viral fusogen, glycoprotein B (gB), and for the pentameric gH/gL complex (pentamer) have been solved. A novel virion gH complex consisting of gH bound to UL116 instead of gL was described, and findings supporting the existence of a stable complex between gH/gL and gB were reported. Additional work indicates that the pentamer promotes a mode of cell-associated spread that resists antibody neutralization, as opposed to the trimeric gH/gL complex (trimer), which appears to be broadly required for the infectivity of cell-free virions. Finally, viral factors such as UL148 and US16 were identified that can influence the incorporation of the alternative gH/gL complexes into virions. We will review these advances and their implications for understanding HCMV entry and cell tropism.
A T(b) Theorem on Product Spaces

The main result of this paper is a bi-parameter T(b) theorem for the case that b is a tensor product of two pseudo-accretive functions. In the proof, we also discuss the L^2 boundedness of different types of the b-adapted bi-parameter paraproducts.
Characterization of Mutations in the Mitochondrial Encoded Electron Transport Chain Complexes in Acute Myeloid Leukemia

Acute Myeloid Leukemia is a devastating and heterogeneous, hematological malignancy characterized by the uncontrolled proliferation of undifferentiated myeloid progenitor cells—blasts. Mutations in certain mitochondrial proteins, such as IDH2 have been shown to contribute to leukemogenesis. However, the role of mutations in mitochondrial-encoded Electron Transport Chain (ETC) genes have thus far not been well elucidated in AML. Here, we use TCGA data to characterize mutations in the ETC genes and their association with clinical outcomes in AML. We found that mitochondrial ETC mutations—in Complex I, III, IV and/or V (ATP Synthase)—were present in 8% of patients with AML and were significantly more frequent in older patients. Patients with ETC mutations had worse overall survival than ETC wild type patients (OS: 9.3 vs 20.1 months; p-value: 0.007). Additionally, mutations in either or both Complex I and IV were associated with TP53 mutations (p-value: 0.009), and among TP53 mutated patients, mutations in either or both Complex I and IV were significantly associated with worse overall survival (OS: 0.85 vs 9.4 months; p-value: 0.008). Elucidation of the mechanisms by which ETC mutations contribute to AML pathogenesis and progression would facilitate the development of novel therapeutic targets.
Blood Clotting: General Pathway

Haemostasis is the process that maintains blood in a fluid state while retaining the capacity to respond to injury by forming a clot to stem blood loss. This process comprises a complex interplay between circulating and cellular proteins which regulate the formation of fibrin and the fibrin/platelet haemostatic plug at the site of injury, and defects in the individual proteins can lead to bleeding disorders (haemophilia). Several of the proteins that participate in haemostasis require vitamin K for function, and inhibition of vitamin K action is commonly used in anticoagulant therapy. Keywords: haemostasis; coagulation; vitamin K; haemophilia; clotting factors
Special moments

In this article, we show that a linear combination X@? of n independent, unbiased Bernoulli random variables {X"k} can match the first 2n moments of a random variable Y which is uniform on an interval. More generally, for each p>=2, each X"k can be uniform on an arithmetic progression of length p. All values of X@? lie in the range of Y, and their ordering as real numbers coincides with dictionary order on the vector (X"1,...,X"n). The construction involves the roots of truncated q-exponential series. It applies to a construction in numerical cubature using error-correcting codes [G. Kuperberg, Numerical cubature using error-correcting codes, arXiv:math.NA/0402047]. For example, when n=2 and p=2, the values of X@? are the 4-point Chebyshev quadrature formula.
The Impact of Partisan Gerrymandering on Political Parties

The relationship between votes and seats in the legislature lies at the heart of democratic governance. However, there has been little previous work on the downstream effects of partisan gerrymandering on the health of political parties. In this study, we conduct a comprehensive examination of the impact of partisan advantage in the districting process on an array of downstream outcomes. We find that districting bias impedes numerous party functions at both the congressional and state house levels. Candidates are less likely to contest districts when their party is disadvantaged by a districting plan. Candidates that do choose to run are more likely to have weak resumes. Donors are less willing to contribute money. And ordinary voters are less apt to support the targeted party. These results suggest that gerrymandering has long-term effects on the health of the democratic process beyond simply costing or gaining parties seats in the legislature.
Paleozoic diversification of terrestrial chitin-degrading bacterial lineages

Establishing the divergence times of groups of organisms is a major goal of evolutionary biology. This is especially challenging for microbial lineages due to the near-absence of preserved physical evidence (diagnostic body fossils or geochemical biomarkers). Horizontal gene transfer (HGT) can serve as a temporal scaffold between microbial groups and other fossil-calibrated clades, potentially improving these estimates. Specifically, HGT to or from organisms with fossil-calibrated age estimates can propagate these constraints to additional groups that lack fossils. While HGT is common between lineages, only a small subset of HGT events are potentially informative for dating microbial groups. Constrained by published fossil-calibrated studies of fungal evolution, molecular clock analyses show that multiple clades of Bacteria likely acquired chitinase homologs via HGT during the very late Neoproterozoic into the early Paleozoic. These results also show that, following these HGT events, recipient terrestrial bacterial clades likely diversified ~ 300–500 million years ago, consistent with established timescales of arthropod and plant terrestrialization. We conclude that these age estimates are broadly consistent with the dispersal of chitinase genes throughout the microbial world in direct response to the evolution and ecological expansion of detrital-chitin producing groups. The convergence of multiple lines of evidence demonstrates the utility of HGT-based dating methods in microbial evolution. The pattern of inheritance of chitinase genes in multiple terrestrial bacterial lineages via HGT processes suggests that these genes, and possibly other genes encoding substrate-specific enzymes, can serve as a “standard candle” for dating microbial lineages across the Tree of Life.
Estimating the Economic Impacts of Climate Change Using Weather Observations

AbstractThis article reviews methods that use historical data on weather, climate, economic activity, and other variables to statistically measure the effect of climate on economic outcomes. This h...
The CDK7 inhibitor THZ1 alters RNA polymerase dynamics at the 5' and 3' ends of genes.

The t(8;21) is one of the most frequent chromosomal translocations associated with acute myeloid leukemia (AML). We found that t(8;21) AML were extremely sensitive to THZ1, which triggered apoptosis after only 4 h. We used precision nuclear run-on transcription sequencing (PROseq) to define the global effects of THZ1 and other CDK inhibitors on RNA polymerase II dynamics. Inhibition of CDK7 using THZ1 caused wide-spread loss of promoter-proximal paused RNA polymerase. This loss of 5' pausing was associated with accumulation of polymerases in the body of a large number of genes. However, there were modest effects on genes regulated by 'super-enhancers'. At the 3' ends of genes, treatment with THZ1 suppressed RNA polymerase 'read through' at the end of the last exon, which resembled a phenotype associated with a mutant RNA polymerase with slower elongation rates. Consistent with this hypothesis, polyA site-sequencing (PolyA-seq) did not detect differences in poly A sites after THZ1 treatment. PROseq analysis after short treatments with THZ1 suggested that these 3' effects were due to altered CDK7 activity at the 5' end of long genes, and were likely to be due to slower rates of elongation.
No Substitute for the Real Thing: The Importance of In-Context Field Experiments in Fundraising

This paper is an empirical case study of fundraising decisions that examines the adequacy of various sources of guidance and demonstrates the unique importance of in-context field experiments.
Electronic impact of concentrated interstitial carbon on physical properties of AISI-316 austenitic stainless steel

Abstract Applying low-temperature carburization to foils of AISI-316 austenitic stainless steel, we obtained precipitate-free solid solutions of interstitial carbon in austenite with uniform, constant carbon levels ≈ 0.1 , orders of magnitude above the equilibrium solubility limit. In this study, we report the impact of such concentrated interstitial carbon on the mass density, electrical conductivity, thermal conductivity, conduction electron concentration, and electron mobility. Compared to the as-received state, the carburized material only has 0.9 of the mass density, 0.8 of the electrical conductivity, and 0.7 of the thermal conductivity. Hall-effect data indicate that the reduced conductivity is not caused by reduced electron mobility, but exclusively by reduced conduction electron concentration. These observations suggest that the interstitial carbon atoms form covalent bonds with the transition metal atoms. With their unique combination of properties, free-standing uniform concentrated solid solutions of interstitial carbon in austenite, realized here in the form of fully low-temperature-carburized foils, can be regarded as a new material that warrants further studies.
How Does Organic Structure Determine Organic Reactivity? Nucleophilic Substitution and Alkene-Forming Elimination Reactions of α-Carbonyl and α-Thiocarbonyl Substituted Benzyl Derivatives

The effect of α-(N,N-dimethylcarbamoyl) and α-(N,N-dimethylthiocarbamoyl) substituents on the rate constants for partitioning of α-substituted 1-(4-methoxyphenyl)ethyl carbocations between nucleophilic addition of 50:50 (v:v) MeOH/H2O (ks, s-1) and deprotonation by this solvent (ke, s-1) have been investigated. The data show that these α-amide and α-thioamide substituents result in 80-fold and ≥30 000-fold decreases, respectively, in ks for capture of the 4-methoxybenzyl carbocation by solvent, but that they lead to much smaller changes in ke for deprotonation of the corresponding α-substituted 1-(4-methoxyphenyl)ethyl carbocations by solvent. The large effect of the α-thioamide substituent on the partitioning of α-substituted 1-phenylethyl carbocations between formation of the products of solvolysis and elimination is therefore due primarily to the effect of this α-substituent on ks for capture of the carbocation by solvent. The results of experimental and computational studies are consistent with the co...
A synthesis of (+)-9a-desmethoxymitomycin A via aziridinyl radical cyclization

Abstract A synthesis of (+)-desmethoxymitomycin A is described. The critical step is a highly stereoselective cyclization of an aziridinyl radical to afford a tetracycle having the same relative and absolute stereochemistry as mitomycin A and C.
Physics Opportunities at a Photon{Photon Collider

The advent of back-scattered laser beams for e{sup +}e{sup -} colliders will allow detailed studies of a large array of high energy {gamma}{gamma} and {gamma}e collision processes with polarized beams. These include tests of electroweak theory in photon-photon annihilation such as {gamma}{gamma} {yields} W{sup +}W{sup -}, {gamma}{gamma} {yields} Higgs bosons, and higher-order loop processes, such as {gamma}{gamma} {yields} {gamma}{gamma}, H{sup 0}Z{sup 0} and ZZ: Methods for measuring the anomalous magnetic and quadrupole moments of the W and Z gauge bosons to high precision in polarized electron-photon and photon-photon collisions are discussed. Since each photon can be resolved into a W{sup +}W{sup -} pair, high energy photon-photon collisions can also provide a remarkably background-free laboratory for studying WW collisions and annihilation. I also review high energy {gamma}{gamma} and e{gamma} tests of quantum chromodynamics, including the production of two gluon jets in photon-photon collisions, deeply virtual Compton scattering on a photon target, and leading-twist single-spin asymmetries for a photon polarized normal to a production plane. Exclusive hadron production processes in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes which are also important for the analysis of exclusive semi-leptonic and two-body hadronic B-decays.
A superior procedure for the conversion of 3-oxoesters to 3H-1,2-dithiole-3-thiones

Abstract The combination of P4S10, sulfur, and hexamethyldisiloxane converts 3-oxoesters to 3H-1,2-dithiole-3-thiones in yields generally superior to those obtained with Lawesson's reagent and without the need for chromatography to remove large amounts of phosphorous-containing byproducts.
Contribution of Sensory Encoding to Measured Bias.

Signal detection theory (SDT) is a widely used theoretical framework that describes how variable sensory signals are integrated with a decision criterion to support perceptual decision-making. SDT provides two key measurements: sensitivity (d′) and bias (c), which reflect the separability of decision variable distributions (signal and noise) and the position of the decision criterion relative to optimal, respectively. Although changes in the subject9s decision criterion can be reflected in changes in bias, decision criterion placement is not the sole contributor to measured bias. Indeed, neuronal representations of bias have been observed in sensory areas, suggesting that some changes in bias are because of effects on sensory encoding. To directly test whether the sensory encoding process can influence bias, we optogenetically manipulated neuronal excitability in primary visual cortex (V1) in mice of both sexes during either an orientation discrimination or a contrast detection task. Increasing excitability in V1 significantly decreased behavioral bias, whereas decreasing excitability had the opposite effect. To determine whether this change in bias is consistent with effects on sensory encoding, we made extracellular recordings from V1 neurons in passively viewing mice. Indeed, we found that optogenetic manipulation of excitability shifted the neuronal bias in the same direction as the behavioral bias. Moreover, manipulating the quality of V1 encoding by changing stimulus contrast or interstimulus interval also resulted in consistent changes in both behavioral and neuronal bias. Thus, changes in sensory encoding are sufficient to drive changes in bias measured using SDT. SIGNIFICANCE STATEMENT Perceptual decision-making involves sensory integration followed by application of a cognitive criterion. Using signal detection theory, one can extract features of the underlying decision variables and rule: sensitivity (d′) and bias (c). Because bias is measured as the difference between the optimal and actual criterion, it is sensitive to both the sensory encoding processes and the placement of the decision criterion. Here, we use behavioral and electrophysiological approaches to demonstrate that measures of bias depend on sensory processes. Optogenetic manipulations of V1 in mice bidirectionally affect both behavioral and neuronal measures of bias with little effect on sensitivity. Thus, changes in sensory encoding influence bias, and the absence of changes in sensitivity do not preclude changes in sensory encoding.
ARCHITECTURE OF PLANETARY SYSTEMS BASED ON KEPLER DATA: NUMBER OF PLANETS AND COPLANARITY

We investigated the underlying architecture of planetary s ystems by deriving the distribution of planet multiplicity (number of planets) and the distribution of orbital inclinations based on the sample of planet candidates discovered by the Kepler mission. The scope of our study included solar-like stars an d planets with orbital periods less than 200 days and with radii between 1.5 and 30 Earth radii, and was based on Kepler planet candidates detected during Quarters 1 through 6. We created models of planetary systems with different distributions of planet multiplicity and inclinations, simulated observat ions of these systems by Kepler, and compared the properties of the transits of detectable objects to actual Kepler planet detections. Specifically, we compared with both the Kepler sample’s transit numbers and normalized transit duration r atios in order to determine each model’s goodness-of-fit. We did not include any constra ints from radial velocity surveys. Based on our best-fit models, 75-80% of planetary systems have 1 or 2 plane ts with orbital periods less than 200 days. In addition, over 85% of planets have orbital inclinations les s than 3 degrees (relative to a common reference plane). This high degree of coplanarity is comparable to tha t seen in our Solar System. These results have implications for planet formation and evolution theories. Low inclinations are consistent with planets forming in a protoplanetary disk, without significant and lasting pe rturbations from other bodies capable of increasing inclinations. Subject headings:methods: statistical ‐ planetary systems ‐ planets and sate llites: general ‐ planets and satellites: detection
Planarization of B7- and B12- clusters by isoelectronic substitution: AlB6- and AlB11-.

Small boron clusters have been shown to be planar from a series of combined photoelectron spectroscopy and theoretical studies. However, a number of boron clusters are quasiplanar, such as B7− and B12−. To elucidate the nature of the nonplanarity in these clusters, we have investigated the electronic structure and chemical bonding of two isoelectronic Al-doped boron clusters, AlB6− and AlB11−. Vibrationally resolved photoelectron spectra were obtained for AlB6−, resulting in an accurate electron affinity (EA) for AlB6 of 2.49 ± 0.03 eV. The photoelectron spectra of AlB11− revealed the presence of two isomers with EAs of 2.16 ± 0.03 and 2.33 ± 0.03 eV, respectively. Global minimum structures of both AlB6− and AlB11− were established from unbiased searches and comparison with the experimental data. The global minimum of AlB6− is nearly planar with a central B atom and an AlB5 six membered ring, in contrast to that of B7−, which possesses a C2v structure with a large distortion from planarity. Two nearly deg...
Chemical Syntheses of Nanocrystalline Nickel Aluminides

Nanocrystalline nickel aluminides (nano-NiAl and nano-Ni3Al) are synthesized by reactions of NiCl2 and LiAlH4 in Et2O or 1,3,5-trimethylbenzene, followed by annealing of the reaction products at 55...
Towards oleananes: Geminal dimethylation at C-4

Abstract A model of the ABC rings of the oleananes, prepared by biomimetic polyene cyclization, shows that the system is sufficiently rigid to prevent epimerization of the C-5 hydrogen with a ketone functionality in place at C-4. Such a sterically hindered ketone has been successfully transformed to a geminal dimethyl group by a three-step procedure.
Convenient Approach to 3,4‐Diarylisoxazoles Based on the Suzuki Cross‐Coupling Reaction

The Suzuki cross-coupling reaction was found effective for rapid access to a series of 3,4-diarylisoxazoles of pharmacological interest. The efficiency of this approach was demonstrated by the synthesis of the highly potent COX-2-selective inhibitor, 4-(5-methyl-3-phenyl-4-isoxazolyl)benzenesulfonamide (valdecoxib), and its analogues. Thus, the coupling reaction between (3-aryl-5-methyl-4-isoxazolyl)boronic acids, prepared in situ from the corresponding bromides using triisopropyl borate, and aryl bromides containing a 4-sulfonamide or 4-methylsulfonyl group under the standard conditions [Pd(PPh3)4, Na2CO3, EtOH-H2O, reflux] yielded the target 3,4-diarylisoxazoles in good yields.
Crystal structures of the high temperature forms of V8O15 and V9O17 and structural trends in the VnO2n−1 Magnéli series

Abstract We report the structure of the metallic high-temperature (ht) form of V9O17, determined from single crystal X-ray diffraction: space group=P-1 a=5.4219(7) A, b=7.0142(9) A, c=14.5252(19) A, α=97.0310(10)°, β=90.9900(10)°, γ=108.9630(10)°, V=517.53(12) A3, and Z=2. We also report refinement of the structure of metallic ht-V8O15, space group=P-1, a=5.4315(17) A, b=7.015(2) A, c=13.147(5) A, α=100.144(4)°, β=95.776(4)°, γ=108.965(3)°, V=459.6(3) A3, and Z=2. The structure of metallic V9O17 is interpreted and discussed in the context of the VnO2n−1 Magneli phases, yielding trends about how the underlying forces contribute to the metal to insulator transition (MIT). The manner in which structural features of the metallic phases change as a function of n supports previous arguments that there is a turnover in the forces leading to the MIT between n=6 and n=8.
FISIK: Framework for the Inference of In Situ Interaction Kinetics from Single-Molecule Imaging Data

Recent experimental and computational developments have been pushing the limits of live-cell single-molecule imaging, enabling the monitoring of intermolecular interactions in their native environment with high spatiotemporal resolution. However, interactions are captured only for the labeled subset of molecules, which tends to be a small fraction. As a result, it has remained a challenge to calculate molecular interaction kinetics, in particular association rates, from live-cell single-molecule tracking data. To overcome this challenge, we developed a mathematical modeling-based Framework for the Inference of in Situ Interaction Kinetics (FISIK) from single-molecule imaging data with substoichiometric labeling. FISIK consists of (I) devising a mathematical model of molecular movement and interactions, mimicking the biological system and data-acquisition setup, and (II) estimating the unknown model parameters, including molecular association and dissociation rates, by fitting the model to experimental single-molecule data. Due to the stochastic nature of the model and data, we adapted the method of indirect inference for model calibration. We validated FISIK using a series of tests in which we simulated trajectories of diffusing molecules that interact with each other, considering a wide range of model parameters, and including resolution limitations, tracking errors, and mismatches between the model and the biological system it mimics. We found that FISIK has the sensitivity to determine association and dissociation rates, with accuracy and precision depending on the labeled fraction of molecules and the extent of molecule tracking errors. For cases where the labeled fraction is too low (e.g., to afford accurate tracking), combining dynamic but sparse single-molecule imaging data with almost-whole population oligomer distribution data improves FISIK's performance. All in all, FISIK is a promising approach for the derivation of molecular interaction kinetics in their native environment from single-molecule imaging data with substoichiometric labeling.
New Advances in Selected Transition Metal-Catalyzed Annulations

This account describes the recent advances on the Pd- catalyzed (4+2)-benzannulation reaction, development of chemo- and regiospecific formal (2+2+2)-cyclotrimerization of alkynes, as well as discovery and evolution of the transition metal-catalyzed cy- cloisomerization of alkynyl ketones and imines into five-membered heteroaromatics.
PQS: a new platform for micellar catalysis. RCM reactions in water, with catalyst recycling.

The first “designer” surfactant containing a covalently bound ruthenium catalyst is reported. This species dissolves freely in water, forming nanomicelles in which ring-closing metathesis reactions on water-insoluble dienic substrates can occur in pure water at room temperature. It can also be recycled continuously without reaction workup.
New low-dimensional quaternary sulfides NaCuMS2 (M = Mn, Fe, Co, and Zn) with the CaAl2Si2-type structure : Synthesis and properties

The synthesis, structure, and electronic properties of a series of new quaternary layered sulfides, NaCuMS2 (M = Mn, Fe, Co, Zn) are reported. The synthesis was accomplished by sulfurization of a mixture of oxide or sulfide and carbonate precursors of the corresponding metals by nitrogen gas charged with CS2. All of the phases crystallize in the trigonal CaAl2Si2-type structure in space group P3m1. The electrical resistivity measurements show that all of the new phases are semiconducting, with room-temperature resistivities ρRT varying from 6.2 × 10-1 to 5 × 10-2 Ω·cm, depending upon the transition metal M. The magnetic susceptibility measurements indicate the presence of localized Mn2+ ions in NaCuMnS2. The NaCuMS2 (M = Fe, Co) phases display temperature-independent paramagnetism, whereas the NaCuZnS2 phase is diamagnetic as expected. In addition, detailed low-temperature magnetic studies of the NaCuFeS2 phase revealed spin-glass-type behavior with the freezing temperature Tf ∼ 50 K.
PRIMA: a gene-centered, RNA-to-protein method for mapping RNA-protein interactions.

ABSTRACTInteractions between RNA binding proteins (RBPs) and mRNAs are critical to post-transcriptional gene regulation. Eukaryotic genomes encode thousands of mRNAs and hundreds of RBPs. However, in contrast to interactions between transcription factors (TFs) and DNA, the interactome between RBPs and RNA has been explored for only a small number of proteins and RNAs. This is largely because the focus has been on using ‘protein-centered’ (RBP-to-RNA) interaction mapping methods that identify the RNAs with which an individual RBP interacts. While powerful, these methods cannot as of yet be applied to the entire RBPome. Moreover, it may be desirable for a researcher to identify the repertoire of RBPs that can interact with an mRNA of interest—in a ‘gene-centered’ manner—yet few such techniques are available. Here, we present Protein-RNA Interaction Mapping Assay (PRIMA) with which an RNA ‘bait’ can be tested versus multiple RBP ‘preys’ in a single experiment. PRIMA is a translation-based assay that examines...
Intramolecular Hydroamination of Difluoropropargyl Amides: Regioselective Synthesis of Fluorinated β- and γ-Lactams‖

Functionalized gem-difluoro β- and γ-lactams were synthesized through a novel intramolecular hydroamination reaction of difluoropropargyl amides. β-Lactams were obtained via a Baldwin disfavored 4-exo-digonal cyclization using palladium acetate as the catalyst, whereas γ-lactams were produced under basic conditions. Acid hydration of γ-lactams produced ketoamides or hemiaminals selectively.
Synthesis of 1,3-dienes of (E,Z) configuration by a three-component coupling strategy

Abstract Three-component coupling of an anionic nucleophile, butadienyltriphenylphosphonium bromide, and an aldehyde gave conjugated dienes of predominantly (E,Z) configuration. Dianions of β-dicarbonyl systems and dicarboxylic acids, and monoanions of sulfones were employed as nucleophiles. Stereoselectivity in favor of an (E,Z)-1,3-diene was highest when a β-dicarbonyl dianion was used in conjunction with an α-branched aldehyde.
Mapping-free variant calling using haplotype reconstruction from k-mer frequencies.

Motivation The standard protocol for detecting variation in DNA is to map millions of short sequence reads to a known reference and find loci that differ. While this approach works well, it cannot be applied where the sample contains dense variants or is too distant from known references. De novo assembly or hybrid methods can recover genomic variation, but the cost of computation is often much higher. We developed a novel k-mer algorithm and software implementation, Kestrel, capable of characterizing densely packed SNPs and large indels without mapping, assembly or de Bruijn graphs. Results When applied to mosaic penicillin binding protein (PBP) genes in Streptococcus pneumoniae, we found near perfect concordance with assembled contigs at a fraction of the CPU time. Multilocus sequence typing (MLST) with this approach was able to bypass de novo assemblies. Kestrel has a very low false-positive rate when applied to the whole genome, and while Kestrel identified many variants missed by other methods, limitations of a purely k-mer based approach affect overall sensitivity. Availability and implementation Source code and documentation for a Java implementation of Kestrel can be found at https://github.com/paudano/kestrel. All test code for this publication is located at https://github.com/paudano/kescases. Contact paudano@gatech.edu or fredrik.vannberg@biology.gatech.edu. Supplementary information Supplementary data are available at Bioinformatics online.
Measurements of High-Temperature Silane Pyrolysis Using SiH4 IR Emission and SiH2 Laser Absorption

The thermal decomposition of silane highly diluted in argon was observed behind reflected shock waves over the temperature range from 1060 to 1730 K and pressures between 0.6 and 5.0 atm, making this the first SiH4 decomposition study to thoroughly investigate pressures above 1 atm. Silane and silylene time histories were monitored using the infrared emission of SiH4 near 4.7 μm and laser absorption of a SiH2 A−X transition near 579 nm. Reaction rate coefficients for the first- and second-order forms of the decomposition reaction SiH4 + M = SiH2 + H2 + M were determined from the species measurements for M = Ar. The effects of competing reactions were considered using a detailed reaction mechanism. The bimolecular rate constant over the pressure range considered herein was determined to be k1a = 7.2 × 1015 exp(−E/RT), with k1a in cm3/mol s and E = 45.1 ± 1.2 kcal/mol. This second-order rate coefficient describes the silane decomposition reaction over the entire range of temperatures and pressures herein a...
Fast and Slow Folding in Cytochrome c

Summary. Following early suggestions, 25,26 a role fornucleation has more recently been proposed on the basisof simulated model folding 15,16 and experiment. 1,17,18,27 Cyt c results 1,27 demonstrate the uphill nature of thenucleated transition state, its massively collapsed condi-tion, and the significant time requirement for its formationand imply a long-range search for a nativelike transitionstate topology. The nucleation barrier occurs at the verybeginning of the cyt c folding process. When subsequentlarger barriers (misfold-reorganization barriers) are notencountered, the initial nucleation becomes the rate-limiting step for native state acquisition, subsequentintermediates are kinetically invisible, and folding appearsto be a two-state process. Misfold - Reorganization Barriers Many proteins including cyt c at neutral pH fold on a ˘1s time scale in a multistate way. Until recently this ratewas considered to be extraordinarily fast and was thoughtto be limited by a late intrinsic on-pathway barrier,perhaps the final molten globule to native state transition.A study of cyt
High- and low-temperature La2RuO5 by powder neutron diffraction.

The structure of dilanthanum ruthenium pentoxide was solved by powder neutron diffraction at room temperature and 1.5 K. High-temperature La2RuO5 crystallizes in the monoclinic space group P21/c. Upon cooling, the sample undergoes a phase transition to the triclinic low-temperature form (space group P\overline{1}). This transition leads to pronounced changes in the Ru—O—Ru bond distances, resulting in a dimerization of the ruthenium ions.
Sometimes-Recurse Shuffle - Almost-Random Permutations in Logarithmic Expected Time.

We describe a security-preserving construction of a random permutation of domain size N from a random function, the construction tolerating adversaries asking all N plaintexts, yet employing just Θ(lgN) calls, on average, to the one-bit-output random function. The approach is based on card shuffling. The basic idea is to use the sometimes-recurse transformation: lightly shuffle the deck (with some other shuffle), cut the deck, and then recursively shuffle one of the two halves. Our work builds on a recent paper of Ristenpart and Yilek.
Selective electrochemical deprotection of cinnamyl ethers, esters, and carbamates

Electrochemical deprotection of the cinnamyl moiety from ethers, esters, and carbamates was studied with the focus on O- versus N- selectivity as well as selectivity over allyl or benzyl systems.
Humans incorporate attention-dependent uncertainty into perceptual decisions and confidence

Perceptual decisions are better when they take uncertainty into account. Uncertainty arises not only from the properties of sensory input but also from cognitive sources, such as different levels of attention. However, it is unknown whether humans appropriately adjust for such cognitive sources of uncertainty during perceptual decision-making. Here we show that, in a task in which uncertainty is relevant for performance, human categorization and confidence decisions take into account uncertainty related to attention. We manipulated uncertainty in an orientation categorization task from trial to trial using only an attentional cue. The categorization task was designed to disambiguate decision rules that did or did not depend on attention. Using formal model comparison to evaluate decision behavior, we found that category and confidence decision boundaries shifted as a function of attention in an approximately Bayesian fashion. This means that the observer’s attentional state on each trial contributed probabilistically to the decision computation. This responsiveness of an observer’s decisions to attention-dependent uncertainty should improve perceptual decisions in natural vision, in which attention is unevenly distributed across a scene.
Convenient synthesis of α,β-unsaturated sulfones via a Mizoroki–Heck reaction of arylboronic acids with phenyl vinyl sulfones

Abstract Palladium acetate catalyzed Mizoroki–Heck reaction of arylboronic acids with phenyl vinyl sulfones afford α,β-unsaturated sulfones in good yields.
Phase Image Texture Analysis for Motion Detection in Diffusion MRI (PITA-MDD).

Abstract Purpose Pronounced spin phase artifacts appear in diffusion-weighted imaging (DWI) with only minor subject motion. While DWI data corruption is often identified as signal drop out in diffusion-weighted (DW) magnitude images, DW phase images may have higher sensitivity for detecting subtle subject motion. Methods This article describes a novel method to return a metric of subject motion, computed using an image texture analysis of the DW phase image. This Phase Image Texture Analysis for Motion Detection in dMRI (PITA-MDD) method is computationally fast and reliably detects subject motion from diffusion-weighted images. A threshold of the motion metric was identified to remove motion-corrupted slices, and the effect of removing corrupted slices was assessed on the reconstructed FA maps and fiber tracts. Results Using a motion-metric threshold to remove the motion-corrupted slices results in superior fiber tracts and fractional anisotropy maps. When further compared to a state-of-the-art magnitude-based motion correction method, PITA-MDD was able to detect comparable corrupted slices in a more computationally efficient manner. Conclusion In this study, we evaluated the use of DW phase images to detect motion corruption. The proposed method can be a robust and fast alternative for automatic motion detection in the brain with multiple applications to inform prospective motion correction or as real-time feedback for data quality control during scanning, as well as after data is already acquired.
Byzantine-resilient distributed observers for LTI systems

Consider a linear time-invariant (LTI) dynamical system monitored by a network of sensors, modeled as nodes of an underlying directed communication graph. We study the problem of collaboratively estimating the state of the system when certain nodes are compromised by adversaries. Specifically, we consider a Byzantine adversary model, where a compromised node possesses complete knowledge of the system dynamics and the network, and can deviate arbitrarily from the rules of any prescribed algorithm. We first characterize certain fundamental limitations of any distributed state estimation algorithm in terms of the measurement and communication structure of the nodes. We then develop an attack-resilient, provably correct state estimation algorithm that admits a fully distributed implementation. To characterize feasible network topologies that guarantee success of our proposed technique, we introduce a notion of ‘strong-robustness’ that captures both measurement and communication redundancy. Finally, by drawing connections to bootstrap percolation theory, we argue that given an LTI system and an associated sensor network, the ‘strong-robustness’ property can be checked in polynomial time.
The proof of the l 2 Decoupling Conjecture

We prove the l 2 Decoupling Conjecture for compact hypersurfaces with positive denite second fundamental form and also for the cone. This has a wide range of important consequences. One of them is the validity of the Discrete Restriction Conjecture, which implies the full range of expected L p Strichartz estimates for both the rational and (up to N " losses) the irrational torus. Another one is an improvement in the range for the discrete restriction theorem for lattice points on the sphere. Various applications to Additive Combinatorics, Incidence Geometry and Number Theory are also discussed. Our argument relies on the interplay between linear and multilinear restriction theory.
Holomorphic isometries between products of complex unit balls

We first give an exposition on holomorphic isometries from the Poincare disk to polydisks and from the Poincare disk to the product of the Poincare disk with a complex unit ball. As an application, we provide an example of proper holomorphic map from the unit disk to the complex unit ball that is irrational, algebraic and holomorphic on a neighborhood of the closed unit disk. We also include some new results on holomorphic isometries.
Affine schemes and topological closures in the Zariski-Riemann space of valuation rings

Abstract Let F be a field, let D be a subring of F, and let X be the Zariski–Riemann space of valuation rings containing D and having quotient field F. We consider the Zariski, inverse and patch topologies on X when viewed as a projective limit of projective integral schemes having function field contained in F, and we characterize the locally ringed subspaces of X that are affine schemes.
AdaComp: Adaptive residual gradient compression for data-parallel distributed training

Highly distributed training of Deep Neural Networks (DNNs) on future compute platforms (offering 100 of TeraOps/s of computational capacity) is expected to be severely communication constrained. To overcome this limitation, new gradient compression techniques are needed that are computationally friendly, applicable to a wide variety of layers seen in Deep Neural Networks and adaptable to variations in network architectures as well as their hyper-parameters. In this paper we introduce a novel technique - the Adaptive Residual Gradient Compression ( AdaComp ) scheme. AdaComp is based on localized selection of gradient residues and automatically tunes the compression rate depending on local activity. We show excellent results on a wide spectrum of state of the art Deep Learning models in multiple domains (vision, speech, language), datasets (MNIST, CIFAR10, ImageNet, BN50, Shakespeare), optimizers (SGD with momentum, Adam) and network parameters (number of learners, minibatch-size etc.). Exploiting both sparsity and quantization, we demonstrate end-to-end compression rates of ∼ 200 × for fully-connected and recurrent layers, and ∼ 40 × for convolutional layers, without any noticeable degradation in model accuracies.
Cut-disks for level spheres in link and tangle complements

Wu has shown that if a link or a knot L in S3 in thin position has thin spheres, then the thin sphere of lowest width is an essential meridional surface in the link complement. In this paper we show that if we further assume that L⊂S3 is prime, then the thin sphere of lowest width also does not have any vertical cut-disks. We also prove the result for a specific kind of tangles in S2×[−1,1].
Distributed team formation in multi-agent systems: Stability and approximation

We consider a scenario in which leaders are required to recruit teams of followers. Each leader cannot recruit all followers, but interaction is constrained according to a bipartite network. The objective for each leader is to reach a state of local stability in which it controls a team whose size is equal to a given constraint. We focus on distributed strategies, in which agents have only local information of the network topology and propose a distributed algorithm in which leaders and followers act according to simple local rules. The performance of the algorithm is analyzed with respect to the convergence to a stable solution. Our results are as follows. For any network, the proposed algorithm is shown to converge to an approximate stable solution in polynomial time, namely the leaders quickly form teams in which the total number of additional followers required to satisfy all team size constraints is an arbitrarily small fraction of the entire population. In contrast, for general graphs there can be an exponential time gap between convergence to an approximate solution and to a stable solution.
An exponential random graph modeling approach to creating group-based representative whole-brain connectivity networks

Group-based brain connectivity networks have great appeal for researchers interested in gaining further insight into complex brain function and how it changes across different mental states and disease conditions. Accurately constructing these networks presents a daunting challenge given the difficulties associated with accounting for inter-subject topological variability. Viable approaches to this task must engender networks that capture the constitutive topological properties of the group of subjects' networks that it is aiming to represent. The conventional approach has been to use a mean or median correlation network (Achard et al., 2006; Song et al., 2009; Zuo et al., 2011) to embody a group of networks. However, the degree to which their topological properties conform with those of the groups that they are purported to represent has yet to be explored. Here we investigate the performance of these mean and median correlation networks. We also propose an alternative approach based on an exponential random graph modeling framework and compare its performance to that of the aforementioned conventional approach. Simpson et al. (2011) illustrated the utility of exponential random graph models (ERGMs) for creating brain networks that capture the topological characteristics of a single subject's brain network. However, their advantageousness in the context of producing a brain network that "represents" a group of brain networks has yet to be examined. Here we show that our proposed ERGM approach outperforms the conventional mean and median correlation based approaches and provides an accurate and flexible method for constructing group-based representative brain networks.
Removable Singularities of the cscK Metric

In this paper, we consider a CscK metric defined away from divisor and with metric upper bound and lower bound going to zero in certain rate. And we'll prove that this "nicely" behaved metric is a smooth CscK metric across the divisor.