cssi/SciSciGPT-SciSciNet huggingface dataset:
Discovery, synthesis, and investigation of the antitumor activity of novel piperazinylpyrimidine derivatives

Protein kinases play several pertinent roles in cell proliferation, and targeting these proteins has been shown to be a successful strategy toward controlling different malignancies. Despite the great discovery stories during the last two decades, there is still a demand for anticancer small molecules with the potential of being selective on both the protein kinase and/or the cellular level. A series of novel piperazinylpyrimidine compounds were synthesized and tested for their potential to selectively inhibit the growth of certain tumor cell lines included within the NCI-60 cell line panel. MDA-MB-468, a triple-negative/basal-like breast carcinoma, cell line was among the most sensitive cell lines towards compounds 4 and 15. The three most interesting compounds identified in cellular screens (4, 15, and 16) were subjected to kinase profiling and found to have an interesting selective tendency to target certain kinase subfamily members; PDGFR, CK1, RAF and others. Compound 4 showed a selective tendency to bind to and/or inhibit the function of certain KIT and PDGFRA mutants compared to their wild-type isoforms. Piperazinylpyrimidine based derivatives represent a new class of selective kinase inhibitors. Significantly 4 is more potent at inhibiting oncogenic mutant forms of PDGFR family kinases, which is relevant in terms of its potential use in treating tumors that have become resistant to treatment or driven by such mutations. The clinical demand for agents useful in the control of triple-negative/basal-like breast cancer justifies our interest in compound 15 which is a potent growth inhibitor of MDA-MB-468 cell line.
Playback: a method for evaluating the usability of software and its documentation

Human factors evaluations of software products and accompanying user publications must be conducted so that developers can be certain that the target user population can learn to use the product with a minimum of difficulty and be able to perform the intended tasks efficiently. A methodology is described for obtaining objective measures of product usability by collecting performance data on the user interface without affecting the user or the system being evaluated. The log of stored activity is later played back through the host system for analysis.
New frequency conversion materials for high power lasers

We discuss material properties relevant for high power harmonic conversion and present information about the linear and nonlinear optical characteristics of some new classes of materials. We give an assessment of the possible usefulness of 1-arginine phosphate monohydrate (LAP) as a harmonic generator for high power lasers.
A More Responsible Two-Party System? Accountability for Majority and Minority Party Performance in a Polarized Congress

Existing research suggests that to the extent that accountability for congressional performance occurs, it does so primarily through a referendum on the performance of the majority party. If true, this means that the minority party has no incentive to act responsibly, and may even have an incentive to polarize and obstruct. I argue that Americans do not simply hold one summary evaluation of congressional performance. Instead, partisan polarization in Congress has allowed Americans to form distinct evaluations of each congressional party. When casting ballots in House elections, Americans take into account their evaluations of both congressional parties. As a result, American politics is now closer to the “responsible two-party system” ideal set by the American Political Science Association more than six decades ago.
Thermal rho`s in the quark-gluon plasma

I discuss different models which predict changes in the mass of the thermal {rho} field. I emphasize that while the predictions are strongly model dependent, nevertheless substantial shifts in the thermal {rho} mass are expected to occur at the point of phase transition. As long as the thermal {rho} peak does not become too broad, this should provide a striking signature of the existence of a phase transition.
Moving research into practice: lessons from the US Agency for Healthcare Research and Quality's IDSRN program.

The U.S. Agency for Healthcare Research and Quality's (AHRQ) Integrated Delivery Systems Research Network (IDSRN) program was established to foster public-private collaboration between health services researchers and health care delivery systems. Its broad goal was to link researchers and delivery systems to encourage implementation of research into practice. We evaluated the program to address two primary questions: 1) How successful was IDSRN in generating research findings that could be applied in practice? and 2) What factors facilitate or impede such success? We conducted in-person and telephone interviews with AHRQ staff and nine IDSRN partner organizations and their collaborators, reviewed program documents, analyzed projects funded through the program, and developed case studies of four IDSRN projects judged promising in supporting research implementation. Participants reported that the IDSRN structure was valuable in creating closer ties between researchers and participating health systems. Of the 50 completed projects studied, 30 had an operational effect or use. Some kinds of projects were more successful than others in influencing operations. If certain conditions were met, a variety of partnership models successfully supported implementation. An internal champion was necessary for partnerships involving researchers based outside the delivery system. Case studies identified several factors important to success: responsiveness of project work to delivery system needs, ongoing funding to support multiple project phases, and development of applied products or tools that helped users see their operational relevance. Factors limiting success included limited project funding, competing demands on potential research users, and failure to reach the appropriate audience. Forging stronger partnerships between researchers and delivery systems has the potential to make research more relevant to users, but these benefits require clear goals and appropriate targeting of resources. Trade-offs are inevitable. The health services research community can best consider such trade-offs and set priorities if there is more dialogue to identify areas and approaches where such partnerships may have the most promise. Though it has unique features, the IDSRN experience is relevant to research implementation in diverse settings.
Adsorption of polar molecules on alkali-fluorides

Abstract The isotherms and calorimetric heats of adsorption of the vapors of H 2 O, CH 3 OH, CH 3 NH 2 , and CH 3 CN on micro single crystals of NaF and LiF have been measured. For H 2 O on LiF, a type III isotherm and a low heat of adsorption (5–7 kcal/mole) for a major portion of the monolayer were found. The isotherm of H 2 O on NaF, however, showed a vertical step typical of a phase transition with a concomitant high heat of adsorption of 13–15 kcal/mole. The adsorption of CH 3 OH and that of CH 3 NH 2 were similar on both surfaces with heats of adsorption in the range of 13–14 kcal/mole. The adsorption of CH 3 CN was weaker on both surfaces and gave type III isothrems. The role of lattice dimensions and of hydrogen bonding with the surface F − ions in the determination of the adsorption behaviors is discussed. The non-(100) surface sites which were observed on the carbon replicas of the LiF surface are postulated as the active sites responsible for the initial higher heat of adsorption for all four adsorbates.
Diboson-jets and the search for resonant Zh production

New particles at the TeV-scale may have sizeable decay rates into boosted Higgs bosons or other heavy scalars. Here, we investigate the possibility of identifying such processes when the Higgs/scalar subsequently decays into a pair of W bosons, constituting a highly distinctive “diboson-jet.” These can appear as a simple dilepton (plus ) configuration, as a two-prong jet with an embedded lepton, or as a four-prong jet. We study jet substructure methods to discriminate these objects from their dominant backgrounds. We then demonstrate the use of these techniques in the search for a heavy spin-one Z ′ boson, such as may arise from strong dynamics or an extended gauge sector, utilizing the decay chain Z ′ → Zh → Z(W W (∗)). We find that modes with multiple boosted hadronic Zs and Wstendtoofferthebestprospectsforthehighestaccessiblemasses. For100fb−1 luminosity at the 14 TeV LHC, Z ′ decays into a standard 125 GeV Higgs can be observed with 5σ significance for masses of 1.5-2.5 TeV for a range of models. For a 200 GeV Higgs (requiring nonstandard couplings, such as fermiophobic), the reach may improve to up to 2.5-3.0 TeV.
Prediction of thermal stress and deformations due to phase change in solidifying objects via flux/stress based finite element representations

The paper presents numerical simulations for the prediction of thermal-stress and deformation fields resulting from phase change in solidifying bodies employing new finite element representations. The formulations developed in this paper provide different perspectives and physical interpretation for the modelling/analysis of thermo-mechanical problems and possess several inherent advantages. In comparison to traditional approaches for solving similar problems, the paper employs new computational architectures in conjunction with flux/stress based representations to enhance the overall effectiveness. Comparative numerical applications validate applicability of the formulations for predicting the temperature induced deformations and stresses resulting from effects due to phase change.
Technical Writing: Weaving the Silk Purse

It's no secret that customers frequently complain about programming manuals. In annual meetings, around the office coffee machine, in comp centers neath the abend's red glare — one can hear the people who depend on software documentation raising agonized cries. The problems that can be found in manuals are many, and familiar: minor irritants like Ted Mack spelling, blunders like lost table headings or illegible printing, yellow-brown fogs of vagueness, absent examples, missing information, even the deadly sin of downright factual mistakes — all these flaws are not uncommon.
Insulin resistance and hypertension

Diminished insulin (Ins) sensitivity is a characteristic feature of various pathological conditions such as the cardiometabolic syndrome, Type 2 diabetes, and hypertension. Persons with essential hypertension are more prone than normotensive persons to develop diabetes, and this propensity may reflect decreased ability of Ins to promote relaxation and glucose transport in vascular and skeletal muscle tissue, respectively. There are increasing data suggesting that ANG II acting through its ANG type 1 receptor inhibits the actions of Ins in vascular and skeletal muscle tissue, in part, by interfering with Ins signally through phosphatidylinositol 3-kinase (PI3K) and its downstream protein kinase B (Akt) signaling pathways. This inhibitory action of ANG II is mediated, in part, through stimulation of RhoA activity and oxidative stress. Activated RhoA and increased reactive oxygen species inhibition of PI3K/Akt signaling results in decreased endothelial cell production of nitric oxide, increased myosin light chain activation with vasoconstriction, and reduced skeletal muscle glucose transport.
On Lyman-limit Systems and the Evolution of the Intergalactic Ionizing Background

We study the properties of self-shielding intergalactic absorption systems and their implications for the ionizing background. We find that cosmological simulations post-processed with detailed radiative transfer calculations generally are able to reproduce the observed abundance of Lyman-limit systems, and we highlight possible discrepancies between the observations and simulations. This comparison tests cosmological simulations at overdensities of ~100. Furthermore, we show that the properties of Lyman-limit systems in these simulations, in simple semianalytic arguments, and as suggested by recent observations indicate that a small change in the ionizing emissivity of the sources would have resulted in a much larger change in the amplitude of the intergalactic H I-ionizing background (with this scaling strengthening with increasing redshift). This strong scaling could explain the rapid evolution in the Lyα forest transmission observed at z ≈ 6. Our calculations agree with the suggestion of simpler models that the comoving ionizing emissivity was constant or even increasing from z = 3 to 6. Our calculations also provide a more rigorous estimate than in previous studies for the clumping factor of intergalactic gas after reionization, which we estimate was ≈2-3 at z = 6.
DDoS Attack Detection and Wavelets

This paper presents a systematic method for DDoS attack detection. DDoS attack can be considered a system anomaly or misuse from which abnormal behavior is imposed on network traffic. Attack detection can be performed via abnormal behavior identification. Network traffic characterization with behavior modeling could be a good indication of attack detection. Aggregated traffic has been found to be strong bursty across a wide range of time scales. Wavelet analysis is able to capture complex temporal correlation across multiple time scales with very low computational complexity. We utilize energy distribution based on wavelet analysis to detect DDoS attack traffic. Energy distribution over time will have limited variation if the traffic keeps its behavior over time (i.e. attack-free situation) while an introduction of attack traffic in the network will elicit significant energy distribution deviation in a short time period. Our experimental results with typical Internet traffic trace show that energy distribution variance markedly changes, causing a "spike" when traffic behaviors are affected by DDoS attack. In contrast, normal traffic exhibits a remarkably stationary energy distribution. In addition, this spike in energy distribution variance can be captured in the early stages of an attack, far ahead of congestion build-up, making it an effective detection of the attack.
A new positive/negative selectable marker, puΔtk, for use in embryonic stem cells

A novel positive/negative selection cassette, puDeltatk, was generated. pu(Delta)tk is a bifunctional fusion protein between puromycin N-acetyltransferase (Puro) and a truncated version of herpes simplex virus type 1 thymidine kinase (DeltaTk). Murine embryonic stem (ES) cells transfected with pu(Delta)tk become resistant to puromycin and sensitive to 1-(-2-deoxy-2-fluoro-1-beta-D-arabino-furanosyl)-5-iodouracil (FIAU). Unlike other HSV1 tk transgenes, puDeltatk is readily transmitted through the male germ line. Thus pu(Delta)tk is a convenient positive/negative selectable marker that can be widely used in many ES cell applications.
Visual Perception and the Statistical Properties of Natural Scenes

The environments in which we live and the tasks we must perform to survive and reproduce have shaped the design of our perceptual systems through evolution and experience. Therefore, direct measurement of the statistical regularities in natural environments (scenes) has great potential value for advancing our understanding of visual perception. This review begins with a general discussion of the natural scene statistics approach, of the different kinds of statistics that can be measured, and of some existing measurement techniques. This is followed by a summary of the natural scene statistics measured over the past 20 years. Finally, there is a summary of the hypotheses, models, and experiments that have emerged from the analysis of natural scene statistics.
Solutions of the Quantum Dynamical Yang–Baxter Equation and Dynamical Quantum Groups

The quantum dynamical Yang–Baxter (QDYB) equation is a useful generalization of the quantum Yang–Baxter (QYB) equation. This generalization was introduced by Gervais, Neveu, and Felder. Unlike the QYB equation, the QDYB equation is not an algebraic but a difference equation, with respect to a matrix function rather than a matrix. The QDYB equation and its quasiclassical analogue (the classical dynamical Yang–Baxter equation) arise in several areas of mathematics and mathematical physics (conformal field theory, integrable systems, representation theory). The most interesting solution of the QDYB equation is the elliptic solution, discovered by Felder. In this paper, we prove the first classification results for solutions of the QDYB equation. These results are parallel to the classification of solutions of the classical dynamical Yang–Baxter equation, obtained in our previous paper. All solutions we found can be obtained from Felder's elliptic solution by a limiting process and gauge transformations. Fifteen years ago the quantum Yang–Baxter equation gave rise to the theory of quantum groups. Namely, it turned out that the language of quantum groups (Hopf algebras) is the adequate algebraic language to talk about solutions of the quantum Yang–Baxter equation. In this paper we propose a similar language, originating from Felder's ideas, which we found to be adequate for the dynamical Yang–Baxter equation. This is the language of dynamical quantum groups (or ?-Hopf algebroids), which is the quantum counterpart of the language of dynamical Poisson groupoids, introduced in our previous paper.
Velocity measurements in the wake of an automotive cooling fan

Abstract Axial, radial and tangential velocity component measurements in the wake of an automotive cooling fan have been acquired. The volume flow rate through the system was measured using a unique moment-of-momentum flux device. Time averaged velocity vector directions were approximated by suspending and photographing a tuft in the fan wake. Digital images of the tuft and reference angles were acquired to locate the mean flow angles at 40 positions for four flow rate conditions. Hot-wires in an X configuration were aligned with these mean flow angles at the ( r , θ , x ) locations reported in the paper. The time series data acquired at these locations were phase averaged with respect to a fixed reference point on the rotating fan. An ensemble of 900 realizations provides the sample population for the statistical quantities. These data were acquired such that 370 samples per revolution could be averaged.
A Unique Chemoenzymatic Synthesis of α-Galactosyl Epitope Derivatives Containing Free Amino Groups: Efficient Separation and Further Manipulation

A novel chemoenzymatic approach for the synthesis of oligosacchrides containing free amino groups has been developed in which thermophilic glycosidases and a fusion enzyme containing catalytic domains of uridine-5‘-diphospho-galactose 4-epimerase and α(1→3) galactosyltransferase were used. This methodology, in conjunction with a convenient purification procedure employing ion exchange chromatography, facilitates the lengthy and high-cost process of carbohydrate synthesis. The prepared oligosaccharides range from disaccharide lactosamine (1a), trisaccharide α-Gal-(1→3)-β-Gal-(1→4)-GlcNH2 (2), tetrasaccharide β-Gal-(1→4)-β-GlcNH2-(1→3)-β-Gal-(1→4)-β-Glc-N3 (7), to pentasaccharide α-Gal-(1→3)-β-Gal-(1→4)-β-GlcNH2-(1→3)-β-Gal-(1→4)-β-Glc-N3 (15). Compounds 2 and 15 are derivatives of natural α-Gal epitopes. Both of them have shown comparable activities with their natural parent compounds toward human anti-Gal IgG. This method provides a practical approach for the preparation and purification of oligosaccharid...
DYNAMICAL SUPERSYMMETRY BREAKING ON QUANTUM MODULI SPACES

Abstract Supersymmetry breaking by the quantum deformation of a classical moduli space is considered. A simple, non-chiral, renormalizable model is presented to illustrate this mechanism. The well-known, chiral, SU (3) × SU (2) model and its generalizations are shown to break supersymmetry by this mechanism in the limit Λ 2 ⪢ Λ 3 . Other supersymmetry breaking models, with classical flat directions that are only lifted quantum mechanically, are presented. Finally, by integrating in vector matter, the strongly coupled region of chiral models with a dynamically generated superpotential is shown to be continuously connected to a weakly coupled description in terms of confined degrees of freedom, with supersymmetry broken at tree level.
A multilinear operator for almost product evaluation of Hankel determinants

In a recent paper we have presented a method to evaluate certain Hankel determinants as almost products; i.e. as a sum of a small number of products. The technique to find the explicit form of the almost product relies on differential-convolution equations and trace calculations. In the trace calculations a number of intermediate nonlinear terms involving determinants occur, but only to cancel out in the end. In this paper, we introduce a class of multilinear operators @c acting on tuples of matrices as an alternative to the trace method. These operators do not produce extraneous nonlinear terms, and can be combined easily with differentiation. The paper is self contained. An example of an almost product evaluation using @c-operators is worked out in detail and tables of the @c-operator values on various forms of matrices are provided. We also present an explicit evaluation of a new class of Hankel determinants and conjectures.
Low Surface Brightness Radio Structure in the Field of Gravitational Lens 0957+561

We have produced deep radio maps of the double quasar 0957+561 from multiple-epoch VLA observations. To achieve high sensitivity to extended structure we have rereduced the best available 1.6 GHz observations and have combined 5 GHz data from multiple array configurations. Regions of faint emission approximately 15'' north and south of the radio source G are probably lobes associated with the lensing galaxy. An arc 5'' to the east of G may be a stretched image of emission in the background quasar's environment. At 14 southwest of G we detect a source that we interpret as an image of emission from the quasar's western lobe, which could provide a constraint on the slope of the gravitational potential in the central region of the lens. We explore the consequences of these new constraints with simple lens models of the system.
Interface phonons in semiconductor double heterostructures

Abstract Within the framework of the continuum model, the equation of motion for the polarization vector in a semiconductor double heterostructure is solved exactly for the interface phonon modes. Both the eigenvectors and dispersion relations are obtained analytically. It is shown that the slab modes observed in right-angle Raman scattering in a GaAs quantum can be understood in terms of the interface modes found in this paper.
Orbit Fitting and Uncertainties for Kuiper Belt Objects

We present a procedure for determination of positions and orbital elements, and associated uncertainties, of outer solar system planets. The orbit-fitting procedure is greatly streamlined compared with traditional methods because acceleration can be treated as a perturbation to the inertial motion of the body. These techniques are immediately applicable to Kuiper belt objects, for which recovery observations are costly. Our methods produce positional estimates and uncertainty ellipses even in the face of the substantial degeneracies of short-arc orbit fits; the sole a priori assumption is that the orbit should be bound or nearly so. We use these orbit-fitting techniques to derive a strategy for determining Kuiper belt orbits with a minimal number of observations.
Suppression of two-photon absorption by quantum interference

Electromagnetically induced transparency may lead to suppression of two-photon absorption in a four-level atomic system. This phenomenon is manifested by destructive quantum interference among multiple excitation paths created by a coherent coupling field. We report an experimental observation of such suppression of two-photon absorption in cold ${}^{87}\mathrm{Rb}$ atoms.
On the gain scheduling for networked PI controller over IP network

The potential use of networks for real-time high-performance control and automation is enormous and appealing. Replacing a widely used proportional-integral (PI) controller by a new networked controller for networked control capability can be costly and time-consuming. This paper proposes a methodology based on gain scheduling with respect to real-time IP traffic conditions to enhance the existing PI controller so it can be used over IP networks with a general network protocol like Ethernet. This paper first describes the gain scheduling approach based on constant network delays using a rational function approach. The formulation is extended to random IP network round-trip time (RTT) delays by using the generalized exponential distribution model. Simulation results show that the PI controller with gain scheduling provides significantly better networked control system performance.
Applications of α-alkoxyorganocuprate reagents in the regiospecific synthesis of cyclic homoaldol products

Abstract Cyclic homoaldol products have been prepared via conjugate addition of α-alkoxyorganocuprate reagents to enones. The reactions are regiospecific, providing the homoaldol products in good to excellent yields. The preparation of the cuprates from the α-alkoxyorganostannane precursor is described in detail. Best results were obtained with the higher order cyano cuprate reagent using in-situ trimethylsilyl chloride.
Synthesis of bisindolylmaleimides using a palladium catalyzed cross-coupling reaction

Bisindolylmaleimides are known to be potent and selective PKC inhibitors. A new synthesis of this class of compound is reported. The key step is a Suzuki cross-coupling reaction using a readily available indolylmaleimide triflate intermediate.
Mixed ligand octahedral Co3+ β-diketonates, with acetylacetone, benzoylacetone and dibenzoylmethane. Synthesis, separation of isomers and characterization

Three series of complexes were studied: Co(acetylacetonate)n(dibenzoylmethanato)3-n, Co(acetylacetonate)n(benzoylacetonate)3-n and Co(dibenzoylmethanato)n(benzoylacetonate)3-n. The product mixtures were separated by thin-layer chromatography. Complete separation of all compounds and stereoisomers was obtained. No attempt was made to separate optical isomers which exist for each single stereoisomer. Characterization was by elemental analyses, NMR spectroscopy and the separation characteristics. Electronic absorption spectra were measured in acetonitrile in the 200–800 nm region. Interpretation of the spectral data is provided in terms of ∏ → ∏*, d → ∏*, d → d* transitions. The influence of geometrical isomerism is discussed.
Embeddings with multiple regularity

We introduce (k,l)-regular maps, which generalize two previously studied classes of maps: affinely k-regular maps and totally skew embeddings. We exhibit some explicit examples and obtain bounds on the least dimension of a Euclidean space into which a manifold can be embedded by a (k,l)-regular map. The problem can be regarded as an extension of embedding theory to embeddings with certain non-degeneracy conditions imposed, and is related to approximation theory.
E-Book Platform Competition in the Presence of Two-Sided Network Externalities

The success of the Kindle e-book platform and the increased popularity of e-books among members of the reading community have attracted extensive interest in the high-tech industry. New platform providers are jumping in the market to compete for device and e-book sales. In this paper, we model the direct competition in the e-book platform market through a two-sided network externality model. We show that publishers can influence consumers' e-book platform adoption decisions and the total e-book sales by strategically deciding the size of contents available on each platform.
Tau decays beyond the standard model

In a recent paper, 8 semileptonic parameters were defined to specify the most general Lorentz-invariant spin correlation functions for 2-body τ decays. These parameters can be used to search for anomalous Γ L , Γ T polarized-partial widths, for non-CKM-type leptonic CP violation, and for leptonic T FS violation. They can also be used to bound the effective-mass scales A for “new physics” arising from additional Lorentz structures, e.g. from lepton compositeness, tau weak magnetism, weak electricity, or second-class currents. It is emphasized that (i) for these tests “different modes have different merits” and that (ii) the parameters can be measured either by using spin-correlation techniques without polarized beams, or with longitudinally polarized beams.
Generalized measures in gauge theory

LetP →M be a principalG-bundle. We construct well-defined analogs of Lebesgue measure on the spaceA of connections onP and Haar measure on the groupG of gauge transformations. More precisely, we define algebras of ‘cylinder functions’ on the spacesA,G, andA/G, and define generalized measures on these spaces as continuous linear functionals on the corresponding algebras. Borrowing some ideas from lattice gauge theory, we characterize generalized measures onA,G, andA/G in terms of graphs embedded inM. We use this characterization to construct generalized measures onA andG whenG is compact. The ‘uniform’ generalized measure onA is invariant under the group of automorphisms ofP. It projects down to the generalized measure onA/G considered by Ashtekar and Lewandowski in the caseG = SU(n). The ‘generalized Haar measure’ onG is right- and left-invariant as well as Aut(P)-invariant. We show that averaging any generalized measure onA against generalized Haar measure gives aG-invariant generalized measure onA.
Two-Dimensional Electronic Conjugation: Statics and Dynamics at Structural Domains Beyond Molecular Wires

Chemical architectures supporting a high degree of electronic conjugation serve as important functional components in devices and materials for advanced electronic and photonic applications. Increasing the spatial dimensionality of such constructs can fundamentally modify their optoelectronic properties and significantly alter intra- and intermolecular interactions that are crucial for understanding and controlling charge/energy-transfer processes. In this article, emerging design principles in the construction of well-defined conjugated platforms beyond molecular wires are highlighted. Both covalent and noncovalent approaches can be strategically employed to position one-dimensional (1D) substructures in a spatially well-defined manner in order to enhance both structural and functional complexity in a two-dimensional (2D) setting. A predictable and controllable switching mechanism can be designed and implemented with mobile 2D electronic conjugation that operates by correlated motions of inherently rigid 1D subunits. This emerging "dynamic" approach complements and challenges the prevailing "static" paradigm of conjugated chemical architectures.
Iterative abel inversion of optically thick, cylindrically symmetric radiation sources

Abstract An inversion algorithm for obtaining the radial emission and absorption coefficients of a cylindrically symmetric radiation source from transverse profiles of monochromatic radiance and absorptance is described and compared with the algorithm of Elder et al. It is shown that the present method converges to the correct solution, whereas that of Elder et al. does not.
Radial distribution of charged particles in a magnetic field.

The radial spread of charged particles emitted from a point source in a magnetic field is a potential source of systematic error for any experiment where magnetic fields guide charged particles to detectors with finite size. Assuming uniform probability as a function of the phase along the particle’s helical trajectory, an analytic solution for the radial probability distribution function follows which applies to experiments in which particles are generated throughout a volume that spans a sufficient length along the axis of a homogeneous magnetic field. This approach leads to the same result as a different derivation given by Dubbers et al., Nucl. Instrum. Methods Phys. Res., Sect. A 763, 112–119 (2014). But the constant phase approximation does not strictly apply to finite source volumes or fixed positions, which lead to local maxima in the radial distribution of emitted particles at the plane of the detector. A simple method is given to calculate such distributions, then the effect is demonstrated with data from a 207Bi electron-conversion source in the superconducting solenoid magnet spectrometer of the Ultracold Neutron facility at the Los Alamos Neutron Science Center. Implications for neutron beta decay spectroscopy are discussed.
Dynamic Distribution of Displacement and Stress Considerations in the Ultrasonic Immersion Nondestructive Evaluation of Multilayered Plates

In the first part of the analysis displacements and stresses are determined as functions of position within the plate while all layer interfaces are assumed to be rigidly bonded. A smooth interface is subsequently introduced to simulate debonding of two material layers. The composite plate is assumed to be bounded at the bottom by either a free surface, a fluid half-space or an elastic solid half-space. A byproduct of the analysis is the derivation of the reflection and transmission coefficients for the systems
A synthetic and mechanistic investigation into the cobalt(I) catalyzed amination of aryl halides

Employing first-row transition metals in catalytic two-electron transformations remains a synthetic challenge. In order to overcome the common and often deleterious single-electron reactivity, an electron rich ligand was targeted on cobalt. Herein, we report the Co(I) catalyzed amination of aryl halides with lithium hexamethyldisilazide. This transformation features (PPh3)3CoCl (1) as the catalyst and affords structurally diverse and electronically varied primary arylamines in good chemical yields, with the scope of the reaction featuring arylamines that cannot be synthesized via traditional metal-catalyzed amination routes, including 4-aminophenylboronic acid pinacol ester. Stoichiometric reactivity revealed that (PPh3)2CoN(SiMe3)2 (2) is likely generated within the catalytic cycle and could be independently synthesized from the reaction of (PPh3)3CoCl with LiN(SiMe3)2. Catalytic reactivity featuring the Co–amide complex, (PPh3)2CoN(SiMe3)2, showed that it is a competent catalyst, implying that the (PPh3)3CoCl may be serving as a pre-catalyst in the reaction. Both stoichiometric and kinetic studies support the catalytic cycle involving a Co(I) complex. Catalytic reactions featuring Co(II) complexes resulted in undesired biaryl formation, a product that is not observed under standard catalytic conditions and any productive catalytic reactivity likely arises from an in situ reduction of Co(II) to Co(I). A Hammett study was carried out to differentiate between a closed-shell or radical mechanism, the results of which are consistent with the proposed closed-shell mechanism. Initial studies indicate that this reactivity may be expanded to other bulky nucleophiles.
Enantioselective, organocatalytic reduction of ketones using bifunctional thiourea-amine catalysts.

Prochiral ketones are reduced to enantioenriched, secondary alcohols using catecholborane and a family of air-stable, bifunctional thiourea−amine organocatalysts. Asymmetric induction is proposed to arise from the in situ complexation between the borane and chiral thiourea−amine organocatalyst resulting in a stereochemically biased boronate−amine complex. The hydride in the complex is endowed with enhanced nucleophilicity while the thiourea concomitantly embraces and activates the carbonyl.
Target tracking in maneuver-centered coordinates

Aircraft targets normally maneuver on circular paths, which has led to tracking filters based on circular turns. A coordinate system to track circular maneuvers with a simple Kalman filter is introduced. This system is a polar coordinate system located at the center of the maneuver. It leads to a tracking filter with range, angle, and angular velocity in the state vector. Simulation results are presented, showing that the algorithm displays improved performance over methods based on constant x-y acceleration when tracking circular turns. >
The linear trace Harnack quadratic on a steady gradient Ricci soliton satisfies the heat equation

We show that the linear trace Harnack quadratic on a steady gradient Ricci soliton satisfies the heat equation. Similar result holds for shrinkers. We also present an interpolation between Perelman's and Cao--Hamilton's Harnacks on a steady soliton.
Internal migration and the earnings of married couples in the United States

Economic models of migration recognize that potential changes in income are an important factor in the decision to change geographic location within a country's borders. For married couples, gains need not occur for both spouses, and ‘tied movers’ may on average see their relative earnings fall as a result of internal migration. Previous research suggesting that wives appear on average to be tied movers primarily dates back to the 1970s. Examining data from the 1990s, I find a result similar to this earlier research, with wives losing on average about 20% of their pre-migration earnings. Much of this decline is associated with a decline in work hours for wives. The effect seems to be short-lived, not clearly persisting into the second year following migration.
Investigations of the low-frequency spectral density of cytochrome c upon equilibrium unfolding.

The equilibrium unfolding process of ferric horse heart cytochrome c (cyt c), induced by guanidinium hydrochloride (GdHCl), was studied using UV–vis absorption spectroscopy, resonance Raman spectroscopy, and vibrational coherence spectroscopy (VCS). The unfolding process was successfully fit using a three-state model which included the fully folded (N) and unfolded (U) states, along with an intermediate (I) assigned to a Lys bound heme. The VCS spectra revealed for the first time several low-frequency heme modes that are sensitive to cyt c unfolding: γa (∼50 cm–1), γb (∼80 cm–1), γc (∼100 cm–1), and νs(His-Fe-His) at 205 cm–1. These out-of-plane modes have potential functional relevance and are activated by protein-induced heme distortions. The free energies for the N–I and the I–U transitions at pH 7.0 and 20 °C were found to be 4.6 kcal/M and 11.6 kcal/M, respectively. Imidazole was also introduced to replace the methionine ligand so the unfolding can be modeled as a two-state system. The intensity of t...
Stagnation-point convective heat transfer in frozen boundary layers.

Stagnation point convective heat transfer in frozen boundary layers to surfaces having widely differing catalytic activity in ionized flows
Aggregate Effects of Reducing the Motor Fuels Excise Tax in the United States

The analysis in this article examines the impact of reducing the excise tax on gasoline and diesel fuel on the U.S. economy. The analytical approach used consists of a computable general equilibrium model composed of 14 producing sectors, 14 consuming sectors, 6 household categories classified by income, and a government. The effects are examined of a 4.3 cents per gallon reduction in the excise tax on gasoline and diesel fuel on prices and quantities. The results suggest, for example, a decrease in the tax would result in higher output by the producing sectors (by about $2.86 billion), an expansion in the consumption of goods and services (by about $3.48 billion), and an increase in welfare (by about $3.59 billion). The government would realize a decrease in revenue of about $2.37 billion. When subjected to a sensitivity analysis, the results are reasonably robust with regard to the assumption of the values of the substitution elasticities.
Directed Electrophilic Cyclizations - Efficient Methodology for the Synthesis of Fused Polycyclic Aromatics

A versatile method for the synthesis of complex, fused polycyclic aromatic systems in high chemical yield is described. Construction is achieved using a general two-step synthetic sequence. Pd-catalyzed Suzuki and Negishi type cross-coupling chemistries allow for the preparation of nonfused skeletal ring systems in yields consistently >80%. The critical ring-forming step, which generally proceeds in very high to quantitative yield, utilizes 4-alkoxyphenylethynyl groups and is induced by strong electrophiles such as trifluoroacetic acid and iodonium tetrafluoroborate. The reaction in essence produces phenanthrene moieties which are integrated into extended polycyclic aromatic structures. Fused polycyclic benzenoids as well as benzenoid/thiophene systems may be prepared utilizing this methodology. The scope of the described cross-coupling/cyclization chemistry including mechanistic insights and problematic side reactions are described.
Finite element analysis of heat flow in dual-beam laser welded tailored blanks

A two-dimensional moving adaptive finite element analysis is presented for dual-beam laser welded tailored blanks. The phase change effect, temperature dependence of material properties, and convection and radiation heat transfer are considered. The simulation results show that welding with a dual-beam system to induce preheating reduces cooling rates effectively. The cooling rate in the thin blank is observed to be slightly higher than that in the thick blank at a given temperature. For example, at 650°C, 2 mm away from the weld centerline, the cooling rates are calculated to be 362°C/sec and 373°C/sec in the thick (2 mm) and thin (0.8 mm) blanks, respectively, for a welding speed of 1.5 cm/sec and beam power of 900 W on mild steel. For the same welding conditions, but with a preheating power of 400 W and interbeam spacing of I cm, the cooling rates reduce to 212°C/sec and 228°C/sec in the thick and thin blanks, respectively. Experiments undertaken for verification show close correlation between the simulation and experimental results.
Single-source fault-tolerant broadcasting for two-dimensional meshes without virtual channels☆

Abstract In this paper, the authors propose a fault-tolerant single-source broadcast algorithm for wormhole routed two-dimensional meshes that utilizes neighbor status information to dynamically construct a broadcast spanning tree when up to N − 1 faults are present in an N × N two-dimensional mesh. Correctness proofs for the proposed broadcasting algorithm are presented and the algorithm is also proven to be livelock-and deadlock-free. The proposed virtual source broadcast (VSB) algorithm can be implemented alone without requiring any virtual channels. However, supporting simultaneous unicast and broadcast messages will require two additional virtual channels per physical link in addition to the virtual channels required for the unicast algorithm. The paper also compares the proposed VSB algorithm with broadcasting techniques that have been proposed by other authors.
Gender differences in repeated competition: Evidence from school math contests

Abstract The literature shows that males react more favorably than females to competitive incentives. This well-known result, however, is based on experiments in which participants engage in only a one-shot contest. We conduct a series of math contests in elementary schools which are similar to past experiments except for one notable exception: subjects compete in five sequential contests, rather than a one-shot contest typically used. Although males outperform females in the first period contest, we find no evidence of a male advantage in subsequent periods. Females even outperform males in later periods. The data suggests that the relative overperformance of low-ability males and the underperformance of high-ability females are primarily responsible for the first period results. Additionally, even the first period male advantage disappears when we reduce the time pressure or change the task at hand.
Recent Advances in Silyl Protection of Alcohols

Abstract Silyl protection/deprotection of alcohols continues to play an important role in organic synthesis. New silyl groups and methods for their introduction and removal are constantly being developed and offer chemists a wider range of options in their use. In recent years, though, silyl protecting groups have been given expanded roles beyond their traditional use of temporarily rendering alcohols inactive. Merging the silyl protection/deprotection of alcohols with such modern methodologies as asymmetric techniques, fluorous chemistry, and nanoscience has added additional value to these temporary components of synthetic intermediates. This review covers developments in the use of silyl protecting groups of alcohols reported in the period 2007 to the end of 2011.
The one loop effective action of QED for a general class of electric fields

Abstract We compute the effective action of QED at one loop order for an electric field which points in the ẑ direction and depends arbitrarily upon the light cone time coordinate, x + =(x 0 +x 3 )/ 2 . This calculation generalizes Schwinger's formula for the vacuum persistence probability in the presence of a constant electric field.
Development of a room temperature Hirao reaction

Arylphosphonates were prepared at 25 °C through the palladium-catalyzed coupling of aryl iodides with a silver phosphonate. A wide range of aryl iodides were successfully employed including phenolic substrates as well as those containing an ortho substituent.
List Decoding Tensor Products and Interleaved Codes

We design the first efficient algorithms and prove new combinatorial bounds for list decoding tensor products of codes and interleaved codes. We show that for every code, the ratio of its list decoding radius (LDR) to its minimum distance stays unchanged under the tensor product operation (rather than squaring, as one might expect). This gives the first efficient list decoders and new combinatorial bounds for some natural codes including multivariate polynomials where the degree in each variable is bounded. We show that for every code, its LDR remains unchanged under $m$-wise interleaving for an integer $m$. This generalizes a recent result of Dinur et al. [in Proceedings of the 40th ACM Symposium on Theory of Computing (STOC '08), 2008, pp. 275-284], who proved such a result for interleaved Hadamard codes (equivalently, linear transformations). Using the notion of generalized Hamming weights, we give better list size bounds for both the tensoring and interleaving of binary linear codes. By analyzing the weight distribution of these codes, we reduce the task of bounding the list size to one of bounding the number of close-by low-rank codewords. For decoding linear transformations, using rank reduction together with other ideas, we obtain list size bounds that are tight over small fields. Our results give better bounds on the LDR than what is obtained from the Johnson bound, and yield rather general families of codes decodable beyond the Johnson radius.
Buckled-layered Structure of Zinc Dicyanamide, ZnII[N(CN)2]2

The reaction of dicyanamide and Zn(II) leads to Zn[N(CN)2]2, which has a new structure type, namely, a buckled-layer, noninterpenetrating motif.