cssi/SciSciGPT-SciSciNet huggingface dataset:
C–F→Ln/An interactions in synthetic f-element chemistry

The coordination of C-F moieties to electrophilic metal cations has been increasingly recognized in f-element chemistry over the last two decades. These C-F→Ln/An interactions are readily identified in the solid state and can persist in solution. The binding energies of C-F→Ln/An interactions lead to their ready displacement to expose metal centers to substrates, which is implicated in cationic polymerization catalysts. C-F→Ln/An coordination is also an elementary step in C-F bond activation, proceeding through either homolytic or heterolytic cleavage of chemically inert C-F bonds. The influence of C-F→Ln/An interactions on the geometries of coordination compounds and their electronic impact on metal cations are also examined in this Perspective article.
Quantum Proteolysis by Neutrophils: Implications for Pulmonary Emphysema in α1-Antitrypsin Deficiency

Traditional enzyme kinetics provide a poor explanation for the increased risk of lung injury in alpha 1-antitrypsin (AAT) deficiency. Millimolar concentrations of leukocyte elastase, when released from single azurophil granules of activated neutrophils, lead to evanescent quantum bursts of proteolytic activity before catalysis is quenched by pericellular inhibitors. Herein, we tested the possibility that quantum proteolytic events are abnormal in AAT deficiency. We incubated neutrophils on opsonized fluoresceinated fibronectin in serum from individuals with various AAT phenotypes, and then measured and modeled quantum proteolytic events. The mean areas of the events in serum from heterozygous individuals (Pi MZ and Pi SZ) were slightly, but significantly, larger than those in serum from normal patients (Pi M). In marked contrast, mean areas of events in serum from AAT-deficient individuals were 10-fold larger than those in serum from normal patients. Diffusion modeling predicted that local elastase concentrations exceed AAT concentrations for less than 20 milliseconds and for more than 80 milliseconds in Pi M and Pi Z individuals, respectively. Thus, quantum proteolytic events are abnormally large and prolonged in AAT deficiency, leading directly to an increased risk of tissue injury in the immediate vicinity of activated neutrophils. These results have potentially important implications for the pathogenesis and prevention of lung disease in AAT deficiency.
Quark Orbital Angular Momentum

Generalized parton distributions provide information on the distribution of quarks in impact parameter space. For transversely polarized nucleons, these impact parameter distributions are transversely distorted and this deviation from axial symmetry leads on average to a net transverse force from the spectators on the active quark in a DIS experiment. This force when acting along the whole trajectory of the active quark leads to transverse single-spin asymmetries. For a longitudinally polarized nucleon target, the transverse force implies a torque acting on the quark orbital angular momentum (OAM). The resulting change in OAM as the quark leaves the target equals the difference between the Jaffe–Manohar and Ji OAMs.
Reliability Analysis with Dynamic Reliability Block Diagrams in the Möbius Modeling Tool

Reliability block diagram (RBD) models are a commonly used reliability analysis method. For static RBD models, combinatorial solution techniques are easy and efficient. However, static RBDs are limited in their ability to express varying system state, dependent events, and non-series-parallel topologies. A recent extension to RBDs, called Dynamic Reliability Block Diagrams (DRBD), has eliminated those limitations. This tool paper details the RBD implementation in the Mobius modeling framework and provides technical details for using RBDs independently or in composition with other Mobius modeling formalisms. The paper explains how the graphical front-end provides a user-friendly interface for specifying RBD models. The back-end implementation that interfaces with the Mobius AFI to dene and generate executable models that the Mobius tool uses to evaluate system metrics is also detailed.
Connected Vehicle-Based Adaptive Signal Control and Applications

Basic signal operation strategies allocate green time to different traffic movements to control the flow at an intersection. Signal control applications consider different objectives, such as coordination with multiple intersections, multimodal priority, and safety. Real-time signal control applications rely mainly on infrastructure-based detection data. With the emergence of connected vehicle technology, high-resolution data from connected vehicles will become available for signal control. This paper presents a framework that uses connected vehicle data for adaptive signal control and considers dilemma zone protection, multimodal signal priority, and coordination. Initially, the market penetration rate of connected vehicles will be low, so infrastructure-based detector actuation logic is integrated into the framework to improve performance. Simulation analysis demonstrated good results when the penetration rate was medium to high and that the actuation logic was necessary when the penetration rate was low.
Provable non-convex phase retrieval with outliers: median truncated wirtinger flow

Solving systems of quadratic equations is a central problem in machine learning and signal processing. One important example is phase retrieval, which aims to recover a signal from only magnitudes of its linear measurements. This paper focuses on the situation when the measurements are corrupted by arbitrary outliers, for which the recently developed non-convex gradient descent Wirtinger flow (WF) and truncated Wirtinger flow (TWF) algorithms likely fail. We develop a novel median-TWF algorithm that exploits robustness of sample median to resist arbitrary outliers in the initialization and the gradient update in each iteration. We show that such a non-convex algorithm provably recovers the signal from a near-optimal number of measurements composed of i.i.d. Gaussian entries, up to a logarithmic factor, even when a constant portion of the measurements are corrupted by arbitrary outliers. We further show that median-TWF is also robust when measurements are corrupted by both arbitrary outliers and bounded noise. Our analysis of performance guarantee is accomplished by development of non-trivial concentration measures of median-related quantities, which may be of independent interest. We further provide numerical experiments to demonstrate the effectiveness of the approach.
Milagro - A Low Energy Threshold Extensive Air Shower Array

Observations of high-energy gamma rays from astronomical sources have revolutionized our view of the cosmos. Gamma rays with energies up to ∼ 10 GeV can be observed directly with space-based instruments. Above 100 GeV the low flux of gamma rays requires one to utilize ground-based instruments. Milagro is a new type of gamma-ray detector based on water Cerenkov technology. This new design will enable Milagro to continuously observe the entire overhead sky, and be sensitive to cosmic rays with energies above ∼ 250 GeV. These attributes make Milagro an ideal detector for the study of high-energy transient phenomenon.
Patient-Reported Outcomes and Early Discontinuation in Aromatase Inhibitor-Treated Postmenopausal Women With Early Stage Breast Cancer.

BACKGROUND Early discontinuation of aromatase inhibitors (AIs) is common and leads to poor outcomes but is challenging to predict. In the Exemestane and Letrozole Pharmacogenetics trial, a high rate of early discontinuation due to intolerance was observed. We hypothesized that early changes in patient-reported outcomes (PROs) predict AI discontinuation and that biochemical factors are associated with changes in PROs. PATIENTS AND METHODS Postmenopausal women with early-stage breast cancer enrolled in a prospective randomized trial of exemestane versus letrozole completed questionnaires at baseline and serially over 24 months to assess overall quality of life (EuroQOL Visual Analog Scale [VAS]); mood; and multiple symptoms, including a musculoskeletal symptom cluster. A joint mixed-effects/survival model was used to estimate the effect of the change in PROs on AI discontinuation. Associations between biochemical factors and change in PROs were examined. RESULTS A total of 490 patients were analyzed. Worsening of EuroQOL VAS and the musculoskeletal cluster were associated with the highest risk for early discontinuation (hazard ratio [HR], 2.77 [95% confidence interval (CI), 2.72-2.81; p = .015]; HR, 4.39 [95% CI, 2.40-8.02; p < .0001], respectively). Pharmacokinetics and estrogen metabolism were not consistently associated with change in PRO measures. No clinically significant differences in any PRO between AIs were observed. CONCLUSION Changes in PROs early during AI therapy were associated with treatment discontinuation. Identification of these changes could be used to target interventions in patients at high risk for early discontinuation. IMPLICATIONS FOR PRACTICE Early changes in patient-reported outcomes (PROs) can predict nonpersistence to aromatase inhibitor therapy. If used in clinical practice, PROs might identify women at highest risk for early discontinuation and allow for interventions to improve tolerance before significant toxicities develop. Further research is needed to improve capturing PROs in routine clinical practice.
On a quantum entropy power inequality of Audenaert, Datta, and Ozols

We give a short proof of a recent inequality of Audenaert, Datta, and Ozols, and determine cases of equality.
Copper-Catalyzed Aerobic Oxidation of Hydroxamic Acids Leads to a Mild and Versatile Acylnitroso Ene Reaction

A mild formation of transient acylnitroso intermediates using a copper chloride catalyst and 1 atm of air as the terminal oxidant is described. The mild reaction conditions enable the inter- and intramolecular acylnitroso ene reaction with a wide range of functionalized alkene partners, as well as the first asymmetric variant. Notably, this transformation provides a practical and operationally simple method for effecting allylic amidation using an environmentally benign oxidant and a readily abundant transition metal.
Robust subspace recovery by Tyler's M-estimator

This paper considers the problem of robust subspace recovery: given a set of N points in RD, if many lie in a d-dimensional subspace, then can we recover the underlying subspace? We show that Tyler’s M-estimator can be used to recover the underlying subspace, if the percentage of the inliers is larger than d/D and the data points lie in general position. Empirically, Tyler’s M-estimator compares favorably with other convex subspace recovery algorithms in both simulations and experiments on real data sets.
Nickel-catalyzed site-selective alkylation of unactivated C(sp3)-H bonds.

The direct alkylation of unactivated sp3 C–H bonds of aliphatic amides was achieved via nickel catalysis with the assist of a bidentate directing group. The reaction favors the C–H bonds of methyl groups over the methylene C–H bonds and tolerates various functional groups. Moreover, this reaction shows a predominant preference for sp3 C–H bonds of methyl groups via a five-membered ring intermediate over the sp2 C–H bonds of arenes in the cyclometalation step.
Depositional ice nucleation on monocarboxylic acids: effect of the O:C ratio.

The heterogeneous ice nucleation efficiency of a series of thin C3–C6 monocarboxylic acid films between 180 and 200 K has been investigated using a Knudsen cell flow reactor. At each temperature, the critical ice saturation ratio for depositional nucleation as well as the effective contact angle was found to be strongly dependent on the chemical nature of the film. For the organic acids used in this study, increasing the O:C ratio lowered the supersaturation required for the onset of heterogeneous ice nucleation and decreased the effective angle of contact. This could be the result of an increase in surface hydrophilicity, which allows the film to better adsorb a metastable, icelike layer of water that serves as a template for the new phase of ice. These ice nucleation results are in excellent agreement with ice nucleation on laboratory generated α-pinene secondary organic aerosol as well as on predominantly organic particles collected in Mexico City.
One-pot synthesis of chromeno[2,3-b]isoindolo[1,2-e]pyrrole-12,13-dione derivatives by sequential reaction of ninhydrin, 2-aminochromen-4-ones and arylamines

ABSTRACTStirring an equimolar mixture of ninhydrin 1 and 2-aminochromen-4-ones 2 in CH3COOH at room temperature produced 6a,11a-dihydroxy-6H-chromeno[2,3-b]indeno[2,1-d]pyrrole-11,12(6aH,11aH)-diones 3, which on heating with aromatic amines 6 in acetic acid produced 11b-hydroxy-7-N-arylimino-6H-chromeno[2,3-b]isoindolo[1,2-e]pyrrole-12,13(11bH)-diones 7.
Iron(II)-Catalyzed Intramolecular Aminohydroxylation of Olefins with Functionalized Hydroxylamines

A diastereoselective aminohydroxylation of olefins with a functionalized hydroxylamine is catalyzed by new iron(II) complexes. This efficient intramolecular process readily affords synthetically useful amino alcohols with excellent selectivity (dr up to > 20:1). Asymmetric catalysis with chiral iron(II) complexes and preliminary mechanistic studies reveal an iron nitrenoid is a possible intermediate that can undergo either aminohydroxylation or aziridination, and the selectivity can be controlled by careful selection of counteranion/ligand combinations.
Multicomponent Polymerization. II. The Effect of Mixing on Copolymerization in Continuous Stirred Tank Reactors

Abstract Calculations have been carried out to describe the course of three vinyl copolymerizations which typify free radical copolymerizations. Conversion of monomer to polymer and copolymer average composition, as well as copolymer composition distribution (CCD), have been calculated for these three systems in batch reactors (BR) and in continuous stirred tank reactors which have perfect, homogeneous micromixing (HCSTR) or imperfect mixing which leads to segregation on the microscopic scale (SCSTR). The results of the calculations indicate that conversion and average composition behavior are not necessarily strongly dependent on mixing in a CSTR, although they are in some systems. However, the CCD is strongly affected by mixing in all systems where the composition drifts with conversion. The magnitude of the effect of mixing on CCD increases with conversion. In the limit, a SCSTR gives at high conversion the same CCD as a BR. A HCSTR always gives a monodisperse CCD. Limitations and applications of the c...
Behavioral change in preventive medicine. An efficacy assessment of a physician education module.

We designed and evaluated a program to teach internal medicine residents behavioral counseling skills for multiple risk factor modification. Integrating physician-patient communication, negotiation skills, and the transtheoretical model of behavior change, we used small group discussion and standardized patients. The 18 participating residents increased their ability to modify patient behavior during videotaped interviews, mean pretest/posttest score: 33.1/40.1 (Student’s pairedt test, p<.0001). Physician self-efficacy in screening for risk factors and effecting behavioral change in patients was increased (p<.0001), as were positive attitudes toward psychosocial factors (p<.003). Our teaching effectively increased the residents’ self-efficacy and performance of behavioral counseling.
Theoretical Studies in Isoelectric Focusing

Our overall objective is the development of a process for large scale purification of biologicals by isoelectric focusing (IEF). Thus, it was important to gain a better understanding of the underlying physical phenomena through mathematical modeling and computer simulation of the process. A mathematical model of the steady state in IEF was developed for an L-component system of ampholytes or monovalent buffers. It is based on the fundamental equations describing the components’ dissociation equilibria, mass transport due to diffusion and electromigration, electroneutrality, and the conservation of charge. The model consists of ordinary differential equations coupled to a system of algebraic equations. The validity and usefulness of these simulations has been confirmed in the formulation of actual buffer mixtures for experimental IEF. This model was recently extended to include the transient evolution to a steady state. Furthermore the new formulation applies to other electrophoretic processes, notably isotachophoresis and zone electrophoresis. As a result, we now have the first general model which predicts the behavior of a given chemical system in a variety of electrophoretic processes.
Total synthesis of the akuammiline alkaloid picrinine.

We report the first total synthesis of the complex akuammiline alkaloid picrinine, which was first isolated nearly five decades ago. Our synthetic approach features a concise assembly of the [3.3.1]-azabicyclic core, a key Fischer indolization reaction to forge the natural product’s carbon framework, and a series of delicate late-stage transformations to complete the synthesis. Our synthesis of picrinine also constitutes a formal synthesis of the related polycyclic alkaloid strictamine.
Rhodium-Catalyzed Decarboxylative Cycloaddition Route to Substituted Anilines

A convenient method for preparing substituted anilines via a Rh-catalyzed [2 + 2 + 2] cycloaddition reaction of diynes and 2-oxazolone was discovered. The initial cycloaddition adducts undergo facile decarboxylation of carbon dioxide to afford aniline products. Reaction conditions are mild, and only 3 mol % Rh catalyst is required. High regioselectivity was observed when an unsymmetrical diyne was used as a starting material.
Acoustic Impedance Inversion For Static And Dynamic Characterization of a CO2 EOR Project, Postle Field, Oklahoma

Seismic inversion was applied statically and dynamically to characterize the Morrow A sandstone, a thin fluvial channel sand with a low impedance contrast, located in Postle Field, Texas County, Oklahoma. A CO2 flood enhanced oil recovery project was initiated in Postle Field in 2008. Two seismic surveys over a 6.25 square mile study area were acquired, the first in March 2008 (prior to most injection) and the second in December 2008. Colored Inversion was chosen over model based inversion due to limited well control producing a sub-optimal low frequency model. Inversion enabled multi-attribute static reservoir characterization for important properties such as gross sand thickness. Four potential drilling locations were identified in areas of increased sand thickness, with one set to spud February 1, 2010. In addition, time-lapse changes related to the CO2 injection can be detected in the acoustic impedance inversion difference volumes. Integration of these data with production and surveillance data enables the identification of CO2 flow pathways and bypassed zones, thereby optimizing the CO2 flood management and improving recovery.
Thresholds for the onset of fluid and magnetofluid turbulence

Linear stability calculations conducted in plasma physics are based on the theory of hydrodynamic stability of neutral fluids. The present investigation is concerned with the validity of procedures based on linear stability analysis in six much-studied situations. All have the property that the fluid goes from laminar to turbulent at critical values of some dimensionless number, such as the Reynolds number or the Rayleigh number. The question is, at what threshold values of the dimensionless number do the unstable motions set in, and can these thresholds be predicted by a linear analysis of the stability of the laminar state as the threshold is approached from the stable side. In three cases linear stability analysis clearly seems to fail. These cases include Plane Poiseuille Flow, Plane Couette Flow, and Cylindrical Pipe Flow (Hagen-Poiseuille Flow). Situations in which predictions provided by linear stability analysis are correct are related to Rotating Couette Flow, Thermally-Driven Convection, and Instability of Laminar Boundary Layers.
Methylenation of Perfluoroalkyl Ketones using a Peterson Olefination Approach

An operationally simple, inexpensive, and rapid route for the olefination of a wide array of trifluoromethyl ketones to yield 3,3,3-trifluoromethylpropenes is reported. Using a Peterson olefination approach, the reaction gives good to excellent yields of the alkene products and can be performed without purification of the β-hydroxysilyl intermediate. The reaction can be extended to other perfluoroalkyl substituents and is easily scaled up. The alkenes prepared can be readily transformed into a variety of other perfluoroalkyl-containing compounds.
EMBERS at 4 years: Experiences operating an Open Source Indicators Forecasting System

EMBERS is an anticipatory intelligence system forecasting population-level events in multiple countries of Latin America. A deployed system from 2012, EMBERS has been generating alerts 24x7 by ingesting a broad range of data sources including news, blogs, tweets, machine coded events,currency rates, and food prices. In this paper, we describe our experiences operating EMBERS continuously for nearly 4 years, with specific attention to the discoveries it has enabled, correct as well as missed forecasts, lessons learnt from participating in a forecasting tournament, and our perspectives on the limits of forecasting including ethical considerations.
Selective Hearing: Physician-Ownership and Physicians' Response to New Evidence

Physicians, acting in their role as experts, are often faced with situations where they must trade off personal and patient welfare. Physicians’ incentives vary based on the organizational environment in which they practice. We use the publication of a major clinical trial, which found that a common knee operation does not improve outcomes for patients with osteoarthritis, as an “informational shock” to gauge the impact of physicians’ agency relationships on treatment decisions. Using a 100% sample of procedures in Florida from 1998 to 2010, we find that publication of the trial reduced procedure volume, but the magnitude of the decline was smaller in physician-owned surgery centers. Incentives affected physicians’ reactions to evidence.
Exploiting Reflection to Add Persistence and Query Optimization to a Statically Typed Object-Oriented Language

It is popular and appealing to design and construct a persistent programming language by extending the semantics of a non-persistent language appropriately and then modifying its compiler and run-time system to implement the extended semantics. We describe here how to achieve this, and furthermore, how to support query optimization, which is typically neglected in persistent programming language implementations, through judicious exploitation of reflection. Significantly, we avoid modifying the structure of the source language or its compiler in any way, and minimize and localize the modifications to the run-time system. We work in the context of the Java programming language, and conclude that the key features required in our approach are: a typed intermediate representation (as provided by Java class files), reflection supporting code inspection (an extension to the standard Java virtual machine), and dynamic loading of code generated at run-time. We also require virtual machine extensions to support read and write barriers and to trigger our reflective optimization and code generation. Further, we argue that optimization at the reflective level can remove much of the overhead of the read and write barriers.
Do different attention capture paradigms measure different types of capture

When something captures our attention, why does it do so? This topic has been hotly debated, with some arguing that attention is captured only by salient stimuli (bottom-up view) and others arguing capture is always due to a match between a stimulus and our goals (top-down view). Many different paradigms have provided evidence for 1 view or the other. If either of these strong views are correct, then capture represents a unitary phenomenon, and there should be a high correlation between capture in these paradigms. But if there are different types of capture (top-down, bottom-up), then some attention capture effects should be correlated and some should not. In 2 studies, we collected data from several paradigms used in support of claims of top-down and bottom-up capture in relatively large samples of participants. Contrary to either prediction, measures of capture were not strongly correlated. Results suggest that capture may in fact be strongly determined by idiosyncratic task demands and strategies. Relevant to this lack of relations among tasks, we observed that classic measures of attention capture demonstrated low reliability, especially among measures used to support bottom-up capture. Implications for the low reliability of capture measures are discussed. We also observed that the proportion of participants demonstrating a pattern of responses consistent with capture varied widely among classic measures of capture. Overall, results demonstrate that, even for relatively simple laboratory measures of attention, there are still important gaps in knowledge regarding what these paradigms measure and how they are related.
Fluids with competing interactions. I. Decoding the structure factor to detect and characterize self-limited clustering

We use liquid state theory and computer simulations to gain insights into the shape of the structure factor for fluids of particles interacting via a combination of short-range attractions and long-range repulsions. Such systems can reversibly morph between homogeneous phases and states comprising compact self-limiting clusters. We first highlight trends with respect to the presence and location of the intermediate-range order (IRO) pre-peak in the structure factor, which is commonly associated with clustering, for wide ranges of the tunable parameters that control interparticle interactions (e.g., Debye screening length). Next, for approximately 100 different cluster phases at various conditions (where aggregates range in size from six to sixty monomers), we quantitatively relate the shape of the structure factor to physical characteristics including intercluster distance and cluster size. We also test two previously postulated criteria for identifying the emergence of clustered phases that are based on IRO peak-height and -width, respectively. We find that the criterion based on peak-width, which encodes the IRO thermal correlation length, is more robust across a wide range of conditions and interaction strengths but nonetheless approximate. Ultimately, we recommend a hybrid heuristic drawing on both pre-peak height and width for positively identifying the emergence of clustered states.
Tracking Strains in the Microbiome: Insights from Metagenomics and Models

Transmission usually refers to the movement of pathogenic organisms. Yet, commensal microbes that inhabit the human body also move between individuals and environments. Surprisingly little is known about the transmission of these endogenous microbes, despite increasing realizations of their importance for human health. The health impacts arising from the transmission of commensal bacteria ranges widely, from the prevention of autoimmune disorders to the spread of antibiotic resistance genes. Despite this importance, there are outstanding basic questions: what is the fraction of the microbiome that is transmissible? What are the primary mechanisms of transmission? Which organisms are the most highly transmissible? Higher resolution genomic data is required to accurately link microbial sources (such as environmental reservoirs or other individuals) with sinks (such as a single person’s microbiome). New computational advances enable strain-level resolution of organisms from shotgun metagenomic data, allowing the transmission of strains to be followed over time and after discrete exposure events. Here, we highlight the latest techniques that reveal strain-level resolution from raw metagenomic reads and new studies that are tracking strains across people and environments. We also propose how models of pathogenic transmission may be applied to study the movement of commensals between microbial communities.
Adaptively Secure Garbled Circuits from One-Way Functions

A garbling scheme is used to garble a circuit C and an input x in a way that reveals the output Cx but hides everything else. In many settings, the circuit can be garbled off-line without strict efficiency constraints, but the input must be garbled very efficiently on-line, with much lower complexity than evaluating the circuit. Yao's garbling schemei?ź[31] has essentially optimal on-line complexity, but only achieves selective security, where the adversary must choose the input x prior to seeing the garbled circuit. It has remained an open problem to achieve adaptive security, where the adversary can choose x after seeing the garbled circuit, while preserving on-line efficiency. In this work, we modify Yao's scheme in a way that allows us to prove adaptive security under one-way functions. In our main instantiation we achieve on-line complexity only proportional to the width w of the circuit. Alternatively we can also get an instantiation with on-line complexity only proportional to the depth d and the output size of the circuit, albeit incurring in a $$2^{Od}$$ security loss in our reduction. More broadly, we relate the on-line complexity of adaptively secure garbling schemes in our framework to a certain type of pebble complexity of the circuit. As our maini?źtool, of independent interest, we develop a new notion of somewhere equivocal encryption, which allows us to efficiently equivocate on a small subset of the message bits.
Rhodium‐Catalyzed [5+2] Cycloaddition of 3‐Acyloxy‐1,4‐enyne with Alkene or Allene

We recently developed a completely new type of Rh-catalyzed [5+2] cycloaddition by using 3-acyloxy-1,4-enyne (ACE) as the 5-carbon building block. In this update, we show that ACE can undergo intramolecular [5+2] cycloaddition with either an alkene or an allene in the presence of an appropriate rhodium catalyst and ligands to afford bicyclic compounds with multiple stereogenic centers. In most cases, cis-fused bicyclo[5.3.0]decadienes are prepared highly diastereoselectively.
Superalgebraically convergent smoothly windowed lattice sums for doubly periodic Green functions in three-dimensional space

This work, part I in a two-part series, presents: (i) a simple and highly efficient algorithm for evaluation of quasi-periodic Green functions, as well as (ii) an associated boundary-integral equation method for the numerical solution of problems of scattering of waves by doubly periodic arrays of scatterers in three-dimensional space. Except for certain ‘Wood frequencies’ at which the quasi-periodic Green function ceases to exist, the proposed approach, which is based on smooth windowing functions, gives rise to tapered lattice sums which converge superalgebraically fast to the Green function—that is, faster than any power of the number of terms used. This is in sharp contrast to the extremely slow convergence exhibited by the lattice sums in the absence of smooth windowing. (The Wood-frequency problem is treated in part II.) This paper establishes rigorously the superalgebraic convergence of the windowed lattice sums. A variety of numerical results demonstrate the practical efficiency of the proposed approach.
Cas9-assisted recombineering in C. elegans: Genome editing using in vivo assembly of linear DNAs

Recombineering, the use of endogenous homologous recombination systems to recombine DNA in vivo, is a commonly used technique for genome editing in microbes. Recombineering has not yet been developed for animals, where non-homology-based mechanisms have been thought to dominate DNA repair. Here, we demonstrate, using Caenorhabditis elegans, that linear DNAs with short homologies (∼35 bases) engage in a highly efficient gene conversion mechanism. Linear DNA repair templates with homology to only one side of a double-strand break (DSB) initiate repair efficiently, and short overlaps between templates support template switching. We demonstrate the use of single-stranded, bridging oligonucleotides (ssODNs) to target PCR fragments for repair of DSBs induced by CRISPR/Cas9 on chromosomes. Based on these findings, we develop recombineering strategies for precise genome editing that expand the utility of ssODNs and eliminate in vitro cloning steps for template construction. We apply these methods to the generation of GFP knock-in alleles and gene replacements without co-integrated markers. We conclude that, like microbes, metazoans possess robust homology-dependent repair mechanisms that can be harnessed for recombineering and genome editing.
Fuel prices, restructuring, and natural gas plant operations

Abstract Switching from coal-fired to natural gas-fired generation and increasing the thermal efficiency (energy generated per unit of energy burned) of fossil fuel fired electricity generation plants have been identified as ways of achieving meaningful emission reductions. In this study, we examine the fuel-price responsiveness across gas plant technologies and across the market structures in which the plants operate. We find that there are significant differences in the generation and efficiency responses of gas plants to fuel prices across generation technologies and market structures. Specifically, our results indicate that, regardless of market structure, generation from natural gas combined cycle (NGCC) plants is responsive to both coal and gas prices, but that generation from simple cycle (NGSC) plants only respond to gas prices. On the other hand, with respect to efficiency, we generally find that only NGCC plants operating in deregulated regions show statistically significant efficiency improvements in response to coal price increases and that, generally, neither NGCC or NGSC plants, regardless of market structure, respond in any significant way to gas prices. Finally, using these parameter estimates, we calculate emissions savings from efficiency improvements and fuel-switching possibilities.
Engaging electronic effects for atropselective [5+2]-photocycloaddition of maleimides

Atropisomeric maleimides were synthesized and subjected to atropselective [5+2]-photocycloaddition under direct irradiation to yield azepinone products with high enantio- (ee >98%) and diastereoselectivity (dr >98%). While the ee was dictated by the axial chirality, the dr was influenced by the substituent on the maleimide ring. Interestingly, by tuning the electronics of the substituent, the dr of the product can be reversed.
Topology control for wireless networks with highly-directional antennas

In order to steer antenna beams towards one another for communication, wireless nodes with highly-directional antennas must track the channel state of their neighbors. To keep this overhead manageable, each node must limit the number of neighbors that it tracks. The subset of neighbors that each node chooses to track constitutes a network topology over which traffic can be routed. We consider this topology design problem, taking into account channel modeling, transmission scheduling, and traffic demand. We formulate the optimal topology design problem, with the objective of maximizing the scaling of traffic demand, and propose a distributed method, where each node rapidly builds a segment of the topology around itself by forming connections with its nearest neighbors in discretized angular regions. The method has low complexity and message passing overhead. The resulting topologies are shown to have desirable structural properties and approach the optimal solution in high path loss environments.
Limited-information goodness-of-fit testing of diagnostic classification item response models

Despite the growing popularity of diagnostic classification models (e.g., Rupp et al., 2010, Diagnostic measurement: theory, methods, and applications, Guilford Press, New York, NY) in educational and psychological measurement, methods for testing their absolute goodness of fit to real data remain relatively underdeveloped. For tests of reasonable length and for realistic sample size, full-information test statistics such as Pearson's X2 and the likelihood ratio statistic G2 suffer from sparseness in the underlying contingency table from which they are computed. Recently, limited-information fit statistics such as Maydeu-Olivares and Joe's (2006, Psychometrika, 71, 713) M2 have been found to be quite useful in testing the overall goodness of fit of item response theory models. In this study, we applied Maydeu-Olivares and Joe's (2006, Psychometrika, 71, 713) M2 statistic to diagnostic classification models. Through a series of simulation studies, we found that M2 is well calibrated across a wide range of diagnostic model structures and was sensitive to certain misspecifications of the item model (e.g., fitting disjunctive models to data generated according to a conjunctive model), errors in the Q-matrix (adding or omitting paths, omitting a latent variable), and violations of local item independence due to unmodelled testlet effects. On the other hand, M2 was largely insensitive to misspecifications in the distribution of higher-order latent dimensions and to the specification of an extraneous attribute. To complement the analyses of the overall model goodness of fit using M2 , we investigated the utility of the Chen and Thissen (1997, J. Educ. Behav. Stat., 22, 265) local dependence statistic XLD2 for characterizing sources of misfit, an important aspect of model appraisal often overlooked in favour of overall statements. The XLD2 statistic was found to be slightly conservative (with Type I error rates consistently below the nominal level) but still useful in pinpointing the sources of misfit. Patterns of local dependence arising due to specific model misspecifications are illustrated. Finally, we used the M2 and XLD2 statistics to evaluate a diagnostic model fit to data from the Trends in Mathematics and Science Study, drawing upon analyses previously conducted by Lee et al., (2011, IJT, 11, 144).
QGIS geoprocessing model to simplify first level seismic microzonation analysis

The seismic microzonation evaluate the seismic hazard at the local scale proposing to identify areas of territory characterized by homogeneous seismic behaviors. The first level of seismic microzoning has the purpose of defining the lithological properties and geometry of geological units that characterize these portions of territory (microzones). The scope of this work is to contribute to the creation of a geoprocessing methodology for topographical, geological, geophysical and geo-technical data aimed at level 1 seismic microzonation map drafting. A QGIS geoprocessing tool was designed to automate one of the analysis commonly performed for the creation of level 1 seismic microzonation maps, in particular to identify unstable zones as polygon features. The result is a polygon layer with areas prone to instability due to a slope value greater than 15 degrees.
Combining Varenicline (Chantix) with Naltrexone Decreases Alcohol Drinking More Effectively Than Does Either Drug Alone in a Rodent Model of Alcoholism

Background This study examined whether varenicline (VAR), or naltrexone (NTX), alone or in combination, reduces alcohol drinking in alcohol-preferring (P) rats with a genetic predisposition toward high voluntary alcohol intake. Methods Alcohol-experienced P rats that had been drinking alcohol (15% v/v) for 2 h/d for 4 weeks were fed either vehicle (VEH), VAR alone (0.5, 1.0, or 2.0 mg/kg body weight [BW]), NTX alone (10.0, 15.0, or 20.0 mg/kg BW), or VAR + NTX in 1 of 4 dose combinations (0.5 VAR + 10.0 NTX, 0.5 VAR + 15.0 NTX, 1.0 VAR + 10.0 NTX, or 1.0 VAR + 15.0 NTX) at 1 hour prior to alcohol access for 10 consecutive days, and the effects on alcohol intake were assessed. Results When administered alone, VAR in doses of 0.5 or 1.0 mg/kg BW did not alter alcohol intake but a dose of 2.0 mg/kg BW decreased alcohol intake. This effect disappeared when drug treatment was terminated. NTX in doses of 10.0 and 15.0 mg/kg BW did not alter alcohol intake but a dose of 20.0 mg/kg BW decreased alcohol intake. Combining low doses of VAR and NTX into a single medication reduced alcohol intake as well as did high doses of each drug alone. Reduced alcohol intake occurred immediately after onset of treatment with the combined medication and continued throughout prolonged treatment. Conclusions Low doses of VAR and NTX, when combined in a single medication, reduce alcohol intake in a rodent model of alcoholism. This approach has the advantage of reducing potential side effects associated with each drug. Lowering the dose of NTX and VAR in a combined treatment approach that maintains efficacy while reducing the incidence of negative side effects may increase patient compliance and improve clinical outcomes for alcoholics and heavy drinkers who want to reduce their alcohol intake.
Realtime online adaptive gesture recognition

We introduce an online adaptive algorithm for learning gesture models. By learning gesture models in an online fashion, the gesture recognition process is made more robust, and the need to train on a large training ensemble is obviated. Hidden Markov models are used to represent the spatial and temporal structure of the gesture. The usual output probability distributions-typically representing appearance-are trained at runtime exploiting the temporal structure (Markov model) that is either trained off-line or is explicitly hand-coded. In the early stages of runtime adaptation, contextural information derived from the application is used to bias the expectation as to which Markov state the system is in at any given time. We describe the Watch and Learn system, a computer vision system which is able to learn simple gestures online for interactive control.
Zernike annular polynomials for imaging systems with annular pupils

Based on our earlier work on Zernike annular polynomials,1 expressions for some higher-order radial polynomials are given, thus providing a complete set up to the sixth order.
Finding the event structure of neuronal spike trains

Neurons in sensory systems convey information about physical stimuli in their spike trains. In vitro, single neurons respond precisely and reliably to the repeated injection of the same fluctuating current, producing regions of elevated firing rate, termed events. Analysis of these spike trains reveals that multiple distinct spike patterns can be identified as trial-to-trial correlations between spike times (Fellous, Tiesinga, Thomas, & Sejnowski, 2004). Finding events in data with realistic spiking statistics is challenging because events belonging to different spike patterns may overlap. We propose a method for finding spiking events that uses contextual information to disambiguate which pattern a trial belongs to. The procedure can be applied to spike trains of the same neuron across multiple trials to detect and separate responses obtained during different brain states. The procedure can also be applied to spike trains from multiple simultaneously recorded neurons in order to identify volleys of near-synchronous activity or to distinguish between excitatory and inhibitory neurons. The procedure was tested using artificial data as well as recordings in vitro in response to fluctuating current waveforms.
Deepening without broadening ? jobs in Ghana's private sector

Creating productive jobs is one of the greatest challenges in Ghana. This paper looks at job creation and its relationship with firm productivity and the quality of jobs among registered firms in the Ghanaian private sector, based on the 2013 World Bank Enterprise Survey. The study looks at the typology of firms in the industry and service sectors, identifying those that have created the most jobs, and the relative quality of these jobs in terms of productivity and firms' average wage bill. Although the formal private sector employs only a tiny share of total employment, the results show that larger and older firms account for the majority of workers, and formal jobs density is highest in Accra (Accra Metropolitan Area and Tema). Large firms also pay higher wages on average, are more productive, and account for most of the aggregate net formal job creation between 2010 and 2012. However, the relationship between size and productivity is positive and statistically significant, mostly driven by the upper part of the firm size distribution, pointing to potential market segmentations as micro, small, and medium firms create fewer jobs and are less productive. Removing barriers to the growth of micro, small, and medium size enterprises, and to the allocation of resources toward more efficient firms should be a key priority for policy makers.
Secure sensor network SUM aggregation with detection of malicious nodes

In-network aggregation is an essential operation which reduces communication overhead and power consumption of resource-constrained sensor network nodes. Sensor nodes are typically organized into an aggregation tree, whereby aggregator nodes collect data from multiple data source nodes, and perform a reduction operation such as sum, average, minimum, etc. The result is then forwarded to other aggregators higher in the hierarchy toward a base station (or sink node) that receives the final outcome of the in-network computation. However, despite its performance benefits, aggregation introduces several difficult security challenges with respect to data confidentiality, integrity and authenticity. In today's outsource-centric computing environments, the aggregation task may be delegated to a third party that is not fully trusted. In addition, even in the absence of outsourcing, nodes may be compromised by a malicious adversary with the purpose of altering aggregation results. To defend against such threats, several mechanisms have been proposed, most of which devise aggregation schemes that rely on cryptography to detect that an attack has occurred. Although they prevent the sink from accepting an incorrect result, such techniques are vulnerable to denial-of-service if a compromised node alters the aggregation result in each round. Several more recent approaches also identify the malicious nodes and exclude them from future computation rounds. However, these incur high communication overhead as they require flooding or other expensive communication models to connect individual nodes with the base station. We propose a flexible aggregation structure (FAS) and an advanced ring structure (ARS) topology that allow secure aggregation and efficient identification of malicious aggregator nodes for the SUM operation. Our scheme uses only symmetric key cryptography, outperforms existing solutions in terms of performance, and guarantees that the aggregate result is correct and that malicious nodes are identified.