cssi/SciSciGPT-SciSciNet huggingface dataset:
Enhancing the quality of learning and understanding of first-year mathematics for computer science related majors

Most courses on discrete mathematics are designed to emphasize knowledge acquisition, and are given to large first year classes, in general. When the goal is to cover the content, the understanding takes a second place. This practice leads to non-enjoyment of the course, a great deal of anxiety, poor performance and a large percentage of failures. In fact, given the choice, most first year students would not do the discrete mathematics course. The opposing beliefs and expectations of the instructors and the students make it a difficult course to teach. However, irrespective of the geographical locations, as instructors, we all share a common goal: we would like our students to acquire the skills to perform complex mental operations so that they will be successful in the classroom as well as their future careers. This paper presents a way to enhance the learning and understanding of discrete mathematics.
An Accurate Numerical Solution to the Kinetics of Breakable Filament Assembly

Proteinaceous aggregation occurs through self-assembly—a process not entirely understood. In a recent article, Knowles and colleagues (2009) presented an analytical theory for amyloid fibril growth via secondary rather than primary nucleation. Remarkably, with only a single kinetic parameter, the authors were able to unify growth characteristics for a variety of experimental data. In essence, they seem to have uncovered the underlying allometric law governing the evolution of filament elongation simply from two coupled nonlinear ordinary differential equations originally obtained from a master equation. While this work adds significantly to our understanding of filament self-assembly, it required an “approximate” analytical solution representation for the moments of the chain length distribution. If this were always true, the discovery of such scaling laws would be infrequent. Here, we show that the same results are found by purely numerical means. In addition, the numerical method used features a highly ...
Toward the synthesis of novel fluorinated building blocks: 3,4-difluorothiophene-1,1-dioxide

Abstract Addition of elemental fluorine to 2,5-dihydrothiophene-1,1-dioxide ( 4 ) provided a mixture of isomeric 3,4-difluoro-2,3,4,5-tetrahydrothiophene-1,1-dioxides ( 5 ) in moderate yield. Photochemical chlorination of each of these isomers gave the same product mixture consisting mainly of trans -3-chloro-3,4-difluoro-2,3,4,5-tetrahydrothiophene-1,1-dioxide ( 9a ) and trans -3,4-dichloro-3,4-difluoro-2,3,4,5-tetrahydrothiophene-1,1-dioxide ( 11b ). Dehydrohalogenation of the former gave 3,4-difluoro-4,5-dihydrothiophene-1,1-dioxide ( 12 ) as the main product, whereas dehydrohalogenation of the latter gave 3,4-difluorothiophene-1,1-dioxide ( 3 ) as the main product.
Convenient synthesis of bis(3-indolyl)-acetylene via sonogashira coupling

Abstract We describe the synthesis of bis(3‐indolyl)acetylene 6 via a Pd‐catalyzed cross‐coupling reaction of iodoindole 8 and 3‐indolylacetylene 9, followed by deprotection of 14 to furnish 6.
Optical absorption in graphene integrated on silicon waveguides

To fully utilize graphene's remarkable optical properties for optoelectronic applications, it needs to be integrated in planar photonic systems. Here, we demonstrate integration of graphene on silicon photonic circuits and precise measurement of the optical absorption coefficient in a graphene/waveguide hybrid structure. A method based on Mach-Zehnder interferometry is employed to achieve high measurement precision and consistency, yielding a maximal value of absorption coefficient of 0.2 dB/μm when graphene is located directly on top of the waveguide. The averaged results obtained from a large number of samples agree with theoretical model utilizing the universal ac conductivity in graphene. Our work provides an important guide for the design and optimization of integrated graphene optoelectronic devices.
Use of displays with packaged statistical programs

During the past few years there has been a great increase in the use of packaged statistical programs. These programs are prepared in a general form. For example, a regression program will allow the user to specify:the number of variables being introduced as a data setthe number of casesthe choice from this data set of the dependent variable the choice of some subset of the input variables to be the independent variablesthe type of input (cards vs. tapes, etc.)the transformation of any variable in the data setthe construction of new variables for some stated function of the input variablesthe stepwise computation of regression functionthe priority with which variables may be considered for introduction into the regression equationthe plotting of residuals vs. various input variables.
Brittle to ductile transition in cleavage fracture

Abstract In many cleavable solids, cleavage cracks can propagate at steady state by laying down a trail of dislocations emanating from the crack tip and lying on planes inclined to the crack front. These crack-tip initiated dislocations produce shielding at the crack tip that reduces both the crack tip tensile stresses and the shear stresses on the inclined planes. They also blunt the crack. Cleavage cracks, can nevertheless, still propagate under appropriately increased stress intensity conditions to keep the crack tip tensile stress constant. A condition is reached in the propagation of such slightly blunted cracks where a small increment in temperature or a decrement in the crack velocity permits the nucleation of a new set of dislocations that produce additional shielding and blunting which tip the balance against the crack-tip tensile stresses. This results in a transition from brittle cleavage to ductile behavior. The steady state specific plastic work that can just be tolerated by a propagating cleavage crack before it catastrophically blunts is calculated to be only of the order of 10% of the specific surface energy. Although most geometrical details of the dislocation emission process are adequately modeled, the calculated brittle to ductile transition temperatures are found to be more than an order of magnitude higher than those that have been experimentally measured. This discrepancy is a result of the present inadequate methods of modeling activation configurations by considering the dislocation loop radius as the only activation parameter, while proper modeling of such configurations must consider also the Burgers shear displacement of the loop as an activation parameter. Such two parameter analyses, however, require accurate information on interlayer atomic shear resistance profiles for specific crystals which are presently not available. The analysis furnishes ready explanations of the toughening effects of so-called “ductilization” treatments and embrittling effect of aging and dislocation locking, as well as the relatively large difference between the lowest levels of toughness between fracture in polycrystals and in single crystals.
Support Structures for Women in Information Technology Careers

This paper examines issues of support for women with Information Technology (IT) careers. Interviews of 38 women with careers in information technology sectors of different industries lasted about 90 minutes and consisted of open-ended questions regarding aspects of their careers and career paths. Research on the lack of women in STEM disciplines focuses mainly on undergraduate education and attracting women to STEM disciplines, focusing on ‘filling the pipeline.’ This research seeks to understand what it takes to have a successful, satisfying career, especially areas of support for women that may influence their success in IT careers. Knowing this may give women help in planning their careers and navigating a male dominated industry.
Keck near-infrared observations of the Orion proplyds: initial results

The Hubble Space Telescope (HST) has produced dramatic images of proto-planetary disks (“proplyds”) surrounding your ( 6 year old) stars embedded in the Orion Nebula. The intense UV radiation field of the high-mass Trapezium stars heats the disk surfaces, drives mass-loss, and produces bright ionization fronts. Many disks are seen in silhouette against the nebular background of the Orion Nebula, or against the proplyd’s own ionization front. The sub-arcsecond resolution and light gathering power of the Keck telescopes in the near-IR provide a unique opportunity to study the earliest phases of planetary disk evolution and disk destruction under intense UV radiation fields. We present initial results from observations of a handful of proplyds using KCAM and NIRSPEC, with and without the adaptive optics (AO) system, on Keck II. These data clearly resolve, both spatially and spectrally, ionization fronts, disks, and a microjet. The data are used to constrain mass-loss rates due to photoevaporation, disk surface wind velocity, and grain size distribution.
Module categories over representations of $SL_q(2)$ and graphs

We classify module categories over the category of representations of quantum $SL(2)$ in a case when $q$ is not a root of unity. In a case when $q$ is a root of unity we classify module categories over the semisimple subquotient of the same category.
Ordering electricity via Internet and Its potentials for smart grid systems

Summary form only given. Leveraging the ubiquitous Internet platform, we propose a novel demand side management system called On-line Purchase Electricity Now (or OPEN system). The new system enables the electricity consumers to send advance demand information to the utility provider through the Internet. This is equivalent to purchasing a book via the online bookstore. The utility company, after consolidating the consumers' advance orders, can decide an optimal generation and distribution scheme to satisfy consumers' future needs. The lead time between the order placement and the later-on consumption allows the service provider to optimize the generation and distribution plan. Such a virtual energy provisioning system can improve the reliability and stability of the electric grid which is increasingly integrated with variable distributed energy sources. Bayesian theory, hypothesis testing, and dynamic pricing are employed to justify the feasibility and applicability of the OPEN system.
Tricks to implement the overlap Dirac operator

Abstract I present several tricks to help implement the overlap Dirac operator numerically.
Instability conditions for some periodic BGK waves in the Vlasov-Poisson system

A one-dimensional, collisionless plasma given by the Vlasov-Poisson system is considered and the stability properties of periodic steady state solutions known as Bernstein-Greene-Kruskal (BGK) waves are investigated. Sufficient conditions are determined under which BGK waves are linearly unstable under perturbations that share the same period as the equilibria. It is also shown that such solutions cannot support a monotonically decreasing particle distribution function.
Are interlocked directors effective monitors

This paper examines whether the presence of interlocked directors on a board is associated with weak governance. For a sample of 3,566 firm-years spanning 2001 to 2003, we find that firms with lower industry-adjusted firm performance are more likely to have interlocked directors. We document that shareholders react negatively to the formation of director interlocks and find that the presence of interlocked directors is associated with lower than optimal pay-performance sensitivity of CEO incentive compensation and reduced sensitivity of CEO turnover to firm performance. Collectively, our results suggest that the presence of interlocked directors is indicative of weak governance.
Ehrhart polynomials of lattice-face polytopes

There is a simple formula for the Ehrhart polynomial of a cyclic polytope. The purpose of this paper is to show that the same formula holds for a more general class of polytopes, lattice-face polytopes. We develop a way of decomposing any d-dimensional simplex in general position into d! signed sets, each of which corresponds to a permutation in the symmetric group G d , and reduce the problem of counting lattice points in a polytope in general position to that of counting lattice points in these special signed sets. Applying this decomposition to a lattice-face simplex, we obtain signed sets with special properties that allow us to count the number of lattice points inside them. We are thus able to conclude the desired formula for the Ehrhart polynomials of lattice-face polytopes.
Partial supersymmetry breaking from five dimensions

Abstract Theories of partial supersymmetry breaking N =2→ N =1 in four dimensions are derived by coupling the N =2 massless gravitino multiplet to N =2 supergravity in five dimensions and performing a generalized dimensional reduction on S 1 / Z 2 with the Scherk–Schwarz mechanism. These theories agree with results that were previously derived from four dimensions.
Ab initio study of low energy electron collisions with ethylene

We present the results of an investigation of elastic electron scattering by ethylene ${\mathrm{C}}_{2}{\mathrm{H}}_{4}$ with incident electron energies ranging from 0.5 to 20 eV, using the complex Kohn variational method. These fully ab initio calculations accurately reproduce experimental angular differential cross sections at energies below 3 eV. Low-energy electron scattering by ethylene is sensitive to the inclusion of electronic correlation and target-distortion effects. We therefore report results that describe the dynamic polarization of the target by the incident electron and involve calculations over a range of different geometries, including the effects of nuclear motion in the resonant ${}^{2}{B}_{2g}$ symmetry with an adiabatic nuclei treatment of the C-C stretch mode. The inclusion of dynamic polarization and the effect of nuclear motion are equally critical in obtaining accurate results. The calculated cross sections are compared with recent experimental measurements.
The g−2 of the muon in localized gravity models☆

Abstract The ( g −2) of the muon is well known to be an important model building constraint on theories beyond the Standard Model. In this Letter, we examine the contributions to ( g −2) μ arising in the Randall–Sundrum model of localized gravity for the case where the Standard Model gauge fields and fermions are both in the bulk. Using the current experimental world average measurement for ( g −2) μ , we find that strong constraints can be placed on the mass of the lightest gauge Kaluza–Klein excitation for a narrow part of the allowed range of the assumed universal 5-dimensional fermion mass parameter, ν . However, employing both perturbativity and fine-tuning constraints we find that we can further restrict the allowed range of the parameter ν to only one fourth of its previous size. The scenario with the SM in the RS bulk is thus tightly constrained, being viable for only a small region of the parameter space.
An extension of Birkhoff's theorem to a class of 2-d gravity theories containing black holes

Abstract A class of 2-dimensional models including 2-d dilaton gravity, spherically symmetric reduction of d-dimensional Einstein gravity and other related theories are classically analyzed. The general analytic solutions in the absence of matter fields other than a U (1) gauge field are obtained under a new gauge choice and recast in the conventional conformal gauge. These solutions imply that Birkhoff's theorem, originally applied to spherically symmetric 4-d Einstein gravity, can be applied to all models we consider. Some issues related to the coupling of massless scalar fields and the quantization are briefly discussed.
I Have the Proof: Providing Proofs of Past Data Possession in Cloud Forensics

Cloud computing has emerged as a popular computing paradigm in recent years. However, today's cloud computing architectures often lack support for computer forensic investigations. A key task of digital forensics is to prove the presence of a particular file in a given storage system. Unfortunately, it is very hard to do so in a cloud given the black-box nature of clouds and the multi-tenant cloud models. In clouds, analyzing the data from a virtual machine instance or data stored in a cloud storage only allows us to investigate the current content of the cloud storage, but not the previous contents. In this paper, we introduce the idea of building proofs of past data possession in the context of a cloud storage service. We present a scheme for creating such proofs and evaluate its performance in a real cloud provider. We also discuss how this proof of past data possession can be used effectively in cloud forensics.
Oxygen sensitive Mn(depe)2X2 complexes

Etude de la reaction reversible avec O 2 : la fixation d'O 2 est maximum vers 18,3°C et nulle a 74°C. Etude RX
α-Hydroxy Esters via Enantioselective Hydrogen-Mediated C−C Coupling: Regiocontrolled Reactions of Silyl-Substituted 1,3-Diynes

Catalytic hydrogenation of ethyl glyoxalate in the presence of 1,3-diynes 4a−9a using chirally modified rhodium catalysts enables formation of α-hydroxy esters 4c−9c in highly optically enriched form. Notably, for such trialkylsilyl-substituted 1,3-diynes, C−C coupling occurs exclusively at the carbon atom bearing silicon. π-Back-bonding from low valent rhodium as described by the Dewar−Chatt−Duncanson model appears to direct the regiochemistry of C−C coupling, as corroborated by calculations of the diyne LUMO coefficients.
A LABORATORY TEST OF THE EQUIVALENCE PRINCIPLE AS PROLOG TO A SPACEBORNE EXPERIMENT

To test the equivalence principle (EP) to an accuracy of at least σ(Δ g)/g = 5 × 10-14, we are developing a modern Galilean experiment. In our principle-of-equivalence measurement (POEM), we directly examine the relative motion of two test mass assemblies (TMA) that are freely falling. Such an experiment tests both for a possible violation of the weak equivalence principle (WEP) and for new forces that might mimic a WEP violation. For the terrestrial version of the experiment, there are three key technologies. A laser gauge measures the separation of the TMA to picometer accuracy in a second as they fall freely in a comoving vacuum chamber. The motion system launches the TMA from their kinematic mounts inside the chamber and keeps the chamber on a trajectory that mimics free fall until the chamber nears the bottom of its motion. It then "bounces" the chamber back to upward motion in preparation for a new launch of the TMA. A capacitance gauge system measures an additional four degrees of freedom of the motion of each TMA. The resulting estimate of the rotation around and translation along the horizontal axes is used to correct systematic errors. We describe the status of POEM and discuss recent progress.
On asymptotically symmetric Banach spaces

A Banach space X is asymptotically symmetric (a.s.) if for some C <∞, for all m ∈ N, for all bounded sequences (xj)j=1 ⊆ X, 1 ≤ i ≤ m, for all permutations σ of {1, . . . ,m} and all ultrafilters U1, . . . ,Um on N, lim n1,U1 . . . lim nm,Um ∥∥∥∥ m ∑ i=1 xini ∥∥∥∥ ≤ C lim nσ(1),Uσ(1) . . . lim nσ(m),Uσ(m) ∥∥∥∥ m ∑
Two-Dimensional Idealized Simulations of the Impact of Multiple Windward Ridges on Orographic Precipitation

Abstract This paper presents two-dimensional (2D) idealized simulations at 1-km grid spacing using the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) in order to illustrate how a series of ridges along a broad windward slope can impact the precipitation distribution and simulated microphysics. The number of windward ridges for a 2000-m mountain of 50-km half-width is varied from 0 to 16 over a 150-km distance using different stratifications, freezing levels, uniform ambient flows, and ridge amplitudes. A few (200–400 m) windward ridges can enhance the precipitation locally over each ridge crest by a factor of 2–3. Meanwhile, a series of 8–16 ridges that are 200–400 m in height can increase the net precipitation averaged over the windward slope by 10%–35%. This average precipitation enhancement is maximized when the ridge spacing is relatively small (<20 km), since there is less time for subsidence drying within the valleys and the m...
Differentiated Citizenship and Contextualized Morality

Political theorists, increasingly, are realizing the virtues of contextuality to conceptual analysis. Just as theory may provide useful standards for the assessment of political practices, so may application of theoretical constructs within particular contexts provide a critical corrective to theory. This essay relates work undertaken within sociolegal studies applying a constitutive methodology to such efforts to contextualize political theorizing. The essay describes how the emphasis placed by constitutive theory on locality and meaning entails a contextual analysis. The essay then demonstrates how a constitutive and contextual approach can enhance our understanding of the moral issues surrounding differentiated citizenship policy. While the most obvious cost associated with differentiated citizenship policy is a loss in formal equality, a contextual assessment demonstrates the prospect of an even deeper, though ultimately contingent, moral loss in self-invention.
The matter of style: Manifestations of personality in cognition, learning, and teaching

The historical roots of cognitive styles are traced in differential psychology, psychoanalytic ego psychology, Gestalt, and cognitive-developmental psychology to illuminate the varied theoretical issues that energize (and fragment) style research. Optimal measurement of cognitive styles as information-processing regularities and as intraindividual contrasts of abilities or other attributes is discussed in terms of both typical performance and contrasted performance on measures of opposing ends of bipolar style dimensions, with special emphasis on the contrasted measurement of field independence versus field dependence. The role of styles as both performance variables and competence variables in learning and teaching is examined, as are various critiques of style research that appear to be excessively polarized in either supporting or undercutting styles as meaningful constructs. This polarization appears to reflect different stances not just with respect to scientific evidence but also with respect to ide...
Superconductivity from a pseudogapped normal state: A mode-coupling approach to precursor superconductivity

We derive a phase diagram for the pseudogap onset temperature ${T}^{*}$ (associated with the breakdown of the Fermi-liquid state, due to strong pairing correlations) and the superconducting instability ${T}_{c}$ as a function of variable pairing strength g. Our diagrammatic approach represents a systematic application of the pairing decoupling scheme of Kadanoff and Martin to arbitrary g and temperatures $Tg{T}_{c}.$ This self-consistent, conserving scheme reveals a delicate competition between the growth (with increasing g) of the pseudogap magnitude and that of ${T}_{c}.$
Complex Modal Analysis of the Swimming Motion of a Whiting

The kinematics of the transverse motion of a swimming fish are analyzed using a complex modal decomposition. Cinematographic images of a swimming whiting (Gadus merlangus) were obtained from the work of Sir James Gray (1933, “Studies in Animal Locomotion III. The Propulsive Mechanism of the Whiting (Gadus merlangus),” J. Exp. Biol., 10, pp. 391–402). The position of the midline for each image was determined and used to produce planar positions of virtual markers distributed along the midline of the fish. Transverse deflections of each virtual marker were then used for the complex orthogonal decomposition of modes. This method was applied to images of a whiting before and after amputation in a Newtonian frame of reference and an “anterior-body-fixed” frame as well. The fish motions were well represented by a single complex mode, which was then used as a modal filter. The extracted mode and modal coordinate were used to estimate the frequency, wavelength, and wave speed. The amputated fish was compared to the nonamputated fish, and the amount of traveling in the respective waveforms was quantified. The dominant complex mode shape and the estimated modal frequency were employed to reanimate the fish motion.
Local properties of Richardson varieties in the Grassmannian via a bounded Robinson-Schensted-Knuth correspondence

The Richardson variety X ? ? in the Grassmannian is defined to be the intersection of the Schubert variety X ? and opposite Schubert variety X ? . We give an explicit Grobner basis for the ideal of the tangent cone at any T-fixed point of X ? ? , thus generalizing a result of Kodiyalam-Raghavan (J. Algebra 270(1):28---54, 2003) and Kreiman-Lakshmibai (Algebra, Arithmetic and Geometry with Applications, 2004). Our proof is based on a generalization of the Robinson-Schensted-Knuth (RSK) correspondence, which we call the bounded RSK (BRSK). We use the Grobner basis result to deduce a formula which computes the multiplicity of X ? ? at any T-fixed point by counting families of nonintersecting lattice paths, thus generalizing a result first proved by Krattenthaler (Sem. Lothar. Comb. 45:B45c, 2000/2001; J. Algebr. Comb. 22:273---288, 2005).
A Method for Reducing the Order of Nonlinear Dynamic Systems

On propose une methode approchee pour reduire l'ordre de systemes dynamiques discrets a n degres de liberte possedant des caracteristiques non lineaires arbitraires. Application a un modele d'elements finis tridimensionnel redondant dont la moitie des elements incorporent des proprietes d'hysteresis
Implied Mortgage Refinancing Thresholds

The optimal prepayment model asserts that rational homeowners will refinance if they can reduce the current value of their liabilities by an amount greater than the refinancing threshold, defined as the cost of carrying the transaction plus the time value of the embedded call option. To compute the notional value of the refinancing threshold, researchers have traditionally relied on discrete- or continuous-time option-pricing models. Using a unique loan level database that links homeowner attributes with property and loan characteristics, this study proposes an alternative approach for estimating the implied value of the refinancing threshold. This empirical method enables us to measure the minimum interest-rate differential needed to justify refinancing conditional on the borrower's creditworthiness, loan-to-value ratio and other observable characteristics.
Status of the Los Alamos free electron laser

Since the initial oscillator experiments were completed last year, the Los Alamos FEL has undergone some major modifications and additions in preparation for the next set of experiments. The laser performance is projected to be substantially enhanced, the rf energy-recovery technique will be demonstrated, and FEL physics measurements will be expanded. The accelerator is now being tuned with very promising performance. The above experiments will be completed during the next year.
k—Very Ample Line Bundles on Del Pezzo Surfaces

A k-very ample line bundle L on a Del Pezzo Surface is numerically characterized, improving the results of Biancofiore— Ceresa in [7].
TESTING THE UNITARITY OF THE CKM MATRIX WITH A SPACE-BASED NEUTRON DECAY EXPERIMENT

If the Standard Model is correct, and fundamental fermions exist only in the three generations, then the CKM matrix should be unitary. However, there remains a question over a deviation from unitarity from the value of the neutron lifetime. We discuss a simple space-based experiment that, at an orbit height of 500 km above Earth, would measure the kinetic-energy, solid-angle, flux spectrum of gravitationally bound neutrons (kinetic energy K< 0.606 eV at this altitude). The difference between the energy spectrum of neutrons that come up from the Earth's atmosphere and that of the undecayed neutrons that return back down to the Earth would yield a measurement of the neutron lifetime. This measurement would be free of the systematics of laboratory experiments. A package of mass < 25 kg could provide a 10-3 precision in two years.
Interferometric measurement of small refraction angles.

Complementary interferograms are suggested as a diagnostic tool in the study of a laser-produced plasma. (AIP)
Ignition of Combustion Modified Polyurethane Foam

Results are presented from an experimental study on the ignition of the combustion modified (fire retarded) polyurethane foam Pyrell® (35.3 kg/m3 and 64.0 kg/m3) in elevated oxygen concentrations, ranging from 30 % to 60 %. The samples are exposed to an external flow and variable radiant heat flux on one face, and insulated on the other faces. The experiments show that Pyrell® undergoes a weak smoldering reaction that requires significant assistance in the form of external heat input in order to propagate. The results also show that given sufficient oxygen and radiant heat flux, the smoldering reaction can produce enough volatile fuel and heat to trigger a gas-phase ignition, i.e. a transition from smoldering to flaming, in pores in the char region. The experiments also indicate that high-density Pyrell® is more ignitable than low-density Pyrell®, which could be explained by the greater solid surface area for smoldering reactions to take place.
Regiospecifically α-13C-Labeled Porphyrins for Studies of Ground-State Hole Transfer in Multiporphyrin Arrays

Insight into the electronic communication between the individual constituents of multicomponent molecular architectures is essential for the rational design of molecular electronic and/or photonic devices. To clock the ground-state hole/electron-transfer process in oxidized multiporphyrin architectures, a p-diphenylethyne-linked zinc porphyrin dyad was prepared wherein one porphyrin bears two 13C atoms and the other porphyrin is unlabeled. The 13C atoms are located at the 1- and 9-positions (α-carbons symmetrically disposed to the position of linker attachment), which are sites of electron/spin density in the a1u HOMO of the porphyrin. The 13C labels were introduced by reaction of KS13CN with allyl bromide to give the allyl isothiocyanate, which upon Trofimov pyrrole synthesis followed by methylation gave 2-(methylthio)pyrrole-2-13C. Reaction of the latter with paraformaldehyde followed by hydrodesulfurization gave dipyrromethane-1,9-13C, which upon condensation with a dipyrromethane-1,9-dicarbinol bearin...
Overexpression, purification and characterization of two pyrimidine kinases involved in the biosynthesis of thiamin: 4-amino-5-hydroxymethyl-2-methylpyrimidine kinase and 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate kinase

Abstract The overexpression, purification and characterization of 4-amino-5-hydroxymethyl-2-methylpyrimidine kinase (HMP kinase) and 4-amino-5-hydroxymethyl-2-methylpyrimidine monophosphate kinase (HMP-P kinase) are described. Surprisingly HMP-P kinase also shows HMP kinase activity. These enzymes are useful reagents for the preparation of intermediates on the thiamin biosynthetic pathway.
Real and Hypothetical Intermediate-Valence AgII/AgIII and AgII/AgI Fluoride Systems as Potential Superconductors

With the aim of gauging their potential as conducting or superconducting materials, we examine the crystal structures and magnetic properties of the roughly one hundred binary, ternary, and quaternary Ag(II) and Ag(III) fluorides in the solid state reported up to date. The Ag(II) cation appears in these species usually in a distorted octahedral environment, either in an [AgF](+) infinite chain or as [AgF(2)] sheets. Sometimes one finds discrete square-planar [AgF(4)](2-) ions. The Ag(III) cation occurs usually in the form of isolated square-planar [AgF(4)](-) ions. Systems containing Ag(III) (d(8)) centers are typically diamagnetic. On the other hand, the rich spectrum of Ag(II) (d(9)) environments in binary and ternary fluorides leads to most diverse magnetic properties, ranging from paramagnetism, through temperature-independent paramagnetism (characteristic for half-filled band and metallic behavior) and antiferromagnetism, to weak ferromagnetism. Ag(II) and Ag(III) have the same d-electron count as Cu(II) (d(9)) and Cu(III) (d(8)), respectively. F(-) and O(2-) ions are isoelectronic, closed-shell (s(2)p(6)) species; both are weak-field ligands. Led by these similarities, and by some experimental evidence, we examine analogies between the superconducting cuprates (Cu(II)/Cu(III)-O(2-) and Cu(II)/Cu(I)-O(2-) systems) and the formally mixed-valence Ag(II)/Ag(III)-F(-) and Ag(II)/Ag(I)-F(-) phases. For this purpose we perform electronic-structure computations for a number of structurally characterized binary and ternary Ag(I), Ag(II), and Ag(III) fluorides and compare the results with similar calculations for oxocuprate superconductors. Electronic levels in the vicinity of the Fermi level (x(2)-y(2) or z(2)) have usually strongly mixed Ag(d)/F(p) character and are Ag-F antibonding, thus providing the potential of efficient vibronic coupling (typical for d(9) systems with substantially covalent bonds). According to our computations this is the result not only of a coincidence in orbital energies; surprisingly the Ag-F bonding is substantially covalent in Ag(II) and Ag(III) fluorides. The electron density of state at the Fermi level (DOS(F)) for silver fluoride materials and frequencies of the metal-ligand stretching modes have values close to those for copper oxides. The above features suggest that properly hole- or electron-doped Ag(II) fluorides might be good BCS-type superconductors. We analyze a comproportionation/disproportionation equilibrium in the hole-doped Ag(II) fluorides, and the possible appearance of holes in the F(p) band. It seems that there is a chance of generating an Ag(III)-F(-)/Ag(II)-F(0) "ionic/covalent" curve crossing in the hole-doped Ag(II)-F(-) fluorides, significantly increasing vibronic coupling.
Do childhood externalizing disorders predict adult depression? A meta-analysis

Childhood externalizing disorders have been linked to adult affective disorders, although some studies fail to substantiate this finding. Multiple longitudinal cohort studies identifying childhood psychopathology and their association with adult psychiatric illness have been published. To examine the association between childhood externalizing symptoms or disorders and the development of adult depression across cohorts, a meta-analysis was performed. Potential studies were identified using a PubMed search through November 2013. All published, prospective, longitudinal, community-sampled cohort studies of children (≤ 13 years) with externalizing symptoms or disorders (aggression, conduct problems, oppositional defiant disorder, conduct disorder), reassessed in adulthood (≥ 18 years) for depressive disorders (major depressive disorder, depressive disorder NOS, or dysthymic disorder) were included. A random effects model was used to summarize the pooled effect sizes. Ancillary analyses considered covariates that could account for variance among studies. Ten studies representing eight cohorts of children initially assessed at age 13 or younger (N = 17,712) were included in the meta-analysis. Childhood externalizing behavior was associated with adult depressive disorders (OR = 1.52, 95 % confidence interval = 1.27–1.80, p < 0.0001). Utilizing Orwin’s Fail-safe N approach, 263 studies with a mean odds ratio of 1.0 would have to be added to the analysis before the cumulative effect would become trivial. Externalizing psychopathology in childhood is associated with the development of unipolar depressive disorders in adulthood.
Overview of the Clouds and the Earth’s Radiant Energy System (CERES) Experiment

This paper presents an overview of the CERES project. It demonstrates how algorithm improvements have lead to improved top-of-atmosphere (TOA) radiative flux accuracy. CERES shortwave flux anomalies are compared with those from Earthshine and ISCCP-FD.
The Shape of Culture: A Study of Contemporary Cultural Patterns in the United States

1. Culture as structure and meaning 2. The American cultural landscape 3. Reproduction and decline 4. Co-ocurrence, tipping in, and bridging 5. Organizational assembly and disassembly 6. Increasing returns on diminishing artists 7. A little more on the hobby horse 8. Masses and classes 9. The transformation of American culture.
Sequential parameter nonstationarity in stock market returns

This paper provides a Bayesian test of parameter nonstationarity and an estimation procedure for the detection of change points in the time series of stock returns. The empirical results indicate that this procedure can identify the change points in the data without prior knowledge and provide substantially more descriptive validity for the distribution of stock returns than competing models.
Dynamic deformability of Plasmodium falciparum- infected erythrocytes exposed to artesunate in vitro

Artesunate (ART) is widely used for the treatment of malaria, but the mechanisms of its effects on parasitized red blood cells (RBCs) are not fully understood. We investigated ART's influence on the dynamic deformability of ring-stage Plasmodium falciparum infected red blood cells (iRBCs) in order to elucidate its role in cellular mechanobiology. The dynamic deformability of RBCs was measured by passing them through a microfluidic device with repeated bottleneck structures. The quasi-static deformability measurement was performed using micropipette aspiration. After ART treatment, microfluidic experiments showed 50% decrease in iRBC transit velocity whereas only small (∼10%) velocity reduction was observed among uninfected RBCs (uRBCs). Micropipette aspiration also revealed ART-induced stiffening in RBC membranes. These results demonstrate, for the first time, that ART reduces the dynamic and quasi-static RBC deformability, which may subsequently influence blood circulation through the microvasculature and spleen cordal meshwork, thus adding a new aspect to artesunate's mechanism of action.
Highly Enantioselective Intramolecular Cyclopropanation Reactions of N-Allylic-N-methyldiazoacetamides Catalyzed by Chiral Dirhodium(II) Carboxamidates

Catalytic diazo decomposition of representative N-allylic-N-methyldiazoacetamides produced the corresponding intramolecular cyclopropanation products in good to excellent yields and with exceptional enantiocontrol. In the simplest case, with N-allyl-N-methyldiazoacetamide, catalysis by dirhodium(II) tetrakis[methyl 2-oxapyrrolidine-5(S)-carboxylate], Rh2(5(S)-MEPY)4, achieved the highest yield and enantioselectivity (93% ee). Dirhodium(II) tetrakis[methyl 2-oxo-1-(3-phenylpropanoyl)imidazolidin-4(S)-carboxylate], Rh2(4S)-MPPIM)4, was preferred for substituted N-allylic-N-methyldiazoacetamides from which 92−95% ee's were obtained in intramolecular cyclopropanation reactions (88−95% yields), even when the catalyst was employed in only 0.1 mol %. Competition with intramolecular dipolar cycloaddition was minimized with the use of N-methyldiazoacetamides relative to N-tert-butyldiazoacetamides.
Numerical Modeling of Submarine Mass-Movement Generated Waves Using Rans Model

In this paper a numerical model for predicting waves generated by nearshore submarine mass-movements is described. The model is based on the Reynolds Averaged Navier Stokes (RANS) equations with the k - e turbulence model. The volume of fluid (VOF) method is employed to track the free surface. The submarine mass movement is prescribed. Numerical results obtained from the present model are validated with laboratory experiments and analytical solutions. Very good agreements are observed.
The next financial crisis

Since the global financial crisis of 2008–2009, much energy has been devoted to efforts to strengthen national and international financial systems. One way of gauging the adequacy and success of those efforts is to “stress test” them against scenarios of major shocks to national economies and international financial markets. I undertake this exercise in the present paper and conclude that recent efforts to strengthen the financial architecture have been only partially successful. The next crisis will not resemble the last crisis, but a next crisis there will inevitably be.
New C–N and C–C bond forming reactions catalyzed by titanium complexes

Titanium(IV) complexes with two basic dimethylamido ligands can be efficient catalysts for alkyne hydroamination by primary amines. Readily prepared pyrrolyl ligands have proven to be especially useful in generating active catalysts for hydroamination and hydrohydrazination. From these reactions, new methodologies for the synthesis of imines, hydrazones, α,β-unsaturated imines, pyridines, indoles, and pyrroles have developed. In addition, a new reaction that is mechanistically related to hydroamination, alkyne iminoamination, has been discovered. Iminoamination, which is a multicomponent coupling between an amine, alkyne, and isonitrile, provides unsymmetrical α,β-unsaturated β-iminoamines in a single, titanium-catalyzed step.
The role of fiscal policy in Japan: a quantitative study

Abstract This paper analyzes the role of fiscal policy in the recent slowdown in Japan. A dynamic general equilibrium model is developed in which fiscal policy can have both expansionary effects (through increasing returns) and contractionary effects (through the increase of public debt and tax burden). A version of the model is calibrated to the Japanese economy and is used to measure the importance of both these effects. We find that, under a wide range of parameters, net expansionary effects are quantitatively small, thus suggesting a limited role for fiscal stabilization
Diphenyloxazaborolidine a new catalyst for enantioselective reduction of ketones

Abstract A variety of ketones can be reduced in high enantioselectivity with the oxazaborolidines derived from commercially available erythro aminodiphenylethanol.
Regioselective asymmetric α,α-bisalkylation of ketones via complex-induced syn-deprotonation of chiral N-amino cyclic carbamate hydrazones.

The first general method for the asymmetric α,α-bisalkylation of ketones having both α- and α′-protons is described. Both excellent regio- and stereoselectivity result. The transformation is enabled by complex-induced syn-deprotonation (CIS-D), which completely reverses the inherent preference of lithium diisopropylamide (LDA) to remove the less sterically hindered of two similarly acidic protons. CIS-D also overrides the normal tendency of LDA to remove the more strongly acidic proton in a substrate having protons differing significantly in their acidity. The regiochemical outcome is, thus, the opposite of that normally obtained for kinetic LDA-mediated deprotonation of ketones and (S)-1-amino-2-methoxymethylpyrrolidine/(R)-1-amino-2-methoxymethylpyrrolidine (SAMP/RAMP)hydrazones. Conveniently, this strategy allows access to either ketone enantiomer using a single enantiomer of the auxiliary. The utility of this method is demonstrated by a concise and highly efficient formal synthesis of both (R)- and (S...
Lagging Behavior in Biological Systems

The lagging behavior is first exemplified by a rapidly stretched spring and a one-dimensional fin to illustrate the phase-lag concept via the thermal and mechanical properties that most engineers are familiar with. The second-order lagging model is then introduced to correlate with drug delivery in tumors and bioheat transfer that involve multiple carriers in heat/mass transport. Analytical expressions for the phase lags are derived, aiming toward revealing different physical origins for delays in different systems. For drug delivery in tumors involving nonequilibrium mass transport, the lagging behavior results from the finite time required for the rupture of liposome in releasing the antitumor drug and the finite time required for tumor cells to absorb drugs. For bioheat transfer involving nonequilibrium heat transport, on the other hand, the lagging behavior results from the finite time required for exchanging heat between tissue and blood. Pharmacodynamical and biological properties affecting the phase lags, as well as the dominating parameters over the lagging response are identified through the nondimensional analysis. Involvement of the thermal Mach number, which measures the speed of blood flow relative to the conventional thermal wave speed, is a new feature in this extension of the lagging model. The second-order effects in lagging are well correlated with the number of carriers involved in nonequilibrium heat and mass transport.
Multivariate analysis with linearizable regressions

We study the class of multivariate distributions in which all bivariate regressions can be linearized by separate transformation of each of the variables. This class seems more realistic than the multivariate normal or the elliptical distributions, and at the same time its study allows us to combine the results from multivariate analysis with optimal scaling and classical multivariate analysis. In particular a two-stage procedure which first scales the variables optimally, and then fits a simultaneous equations model, is studied in detail and is shown to have some desirable properties.
Interferometry And High Speed Photography Of Laser-Driven Flyer Plates

Laser-driven thin (2-10-1 thick) plates of aluminum and copper are accelerated to velocities ≥5 km/s by a 1.06 -11 wavelength Nd:YAG 8 -10 ns FWHM laser pulse at power densities 0.7-4.0 GW/cm2. Accelerations ≥10 9 km/s2 have been achieved. The acceleration and velocity of these 0.4-1.0-mm-diameter plates are experimentally recorded by velocity interferometry (VISAR)1 and the planarity of impact by streak photography.2
Trimethylsilyl chloride/tetramethylethylenediamine facilitated additions of organocopper reagents (RCu) to enones

Abstract Alkylcoppers (RCu) add readily in a conjugate fashion to enones in the presence of TMSCl and TMEDA to give high yields of trimethylsilyl enol ethers.
On-line recognition of hand-generated symbols

With the growth of information processing systems incorporating large data bases, many situations arise in which the data to be entered is a human's analysis of a problem. Often it will be undesirable to require the user to learn to type, and this mode can be cumbersome for random two-dimensional entry on a form or drawing. Using an electronic tablet coupled to a display tube would make it convenient for the user to point to a correct answer or print it in a very natural way. This paper describes a new technique for converting these hand written symbols to code words which can subsequently be processed by a computer.
Stackelberg contention games in multiuser networks

Interactions among selfish users sharing a common transmission channel can be modeled as a noncooperative game using the game theory framework. When selfish users choose their transmission probabilities independently without any coordination mechanism, Nash equilibria usually result in a network collapse. We propose a methodology that transforms the noncooperative game into a Stackelberg game. Stackelberg equilibria of the Stackelberg game can overcome the deficiency of the Nash equilibria of the original game. A particular type of Stackelberg intervention is constructed to show that any positive payoff profile feasible with independent transmission probabilities can be achieved as a Stackelberg equilibrium payoff profile.We discuss criteria to select an operating point of the network and informational requirements for the Stackelberg game. We relax the requirements and examine the effects of relaxation on performance.
Suppression of racemization during the diastereoselective C-3 functionalization of 5-hydroxymethyl-2-phenylthio-2-(5H)-furanones

Abstract The methodology described herein examines the enantio- and stereoselective C-3 functionalization of 5-hydroxymethyl-2-( 5H )-furanones via 1, 4-organocuprate addition as well as the involvement of temperature and TMSCl in the selectivity. The results imply that reaction carried out at −78°C and those carried out at 0°C to R.T. in the presence of TMSCl exhibit both high diastereoselection and enantioselection.