cssi/SciSciGPT-SciSciNet huggingface dataset:
Metal-enhanced fluorescence of carbon nanotubes.

The photoluminescence (PL) quantum yield of single-walled carbon nanotubes (SWNTs) is relatively low, with various quenching effects by metallic species reported in the literature. Here, we report the first case of metal enhanced fluorescence (MEF) of surfactant-coated carbon nanotubes on nanostructured gold substrates. The photoluminescence quantum yield of SWNTs is observed to be enhanced more than 10-fold. The dependence of fluorescence enhancement on metal−nanotube distance and on the surface plasmon resonance (SPR) of the gold substrate for various SWNT chiralities is measured to reveal the mechanism of enhancement. Surfactant-coated SWNTs in direct contact with metal exhibit strong MEF without quenching, suggesting a small quenching distance for SWNTs on the order of the van der Waals distance, beyond which the intrinsically fast nonradiative decay rate in nanotubes is little enhanced by metal. The metal enhanced fluorescence of SWNTs is attributed to radiative lifetime shortening through resonance ...
Examining unconditional preference revelation in choice experiments: a voting game approach

If respondents are strategic, voting in choice experiments may violate the common modelling assumption that everyone votes for his unconditionally most-preferred alternative. This presents a challenge to accurately estimating welfare measures. We conduct a homegrown-value laboratory experiment designed to mimic a three-alternative choice experiment. Two key pieces of information not previously collected from participants are their (1) unconditionally most-preferred alternative and (2) their perception of the likely vote distribution. We are able to identify whether participants adopt a strategy of voting for their second-most-preferred alternative when their most-preferred alternative is believed likely to garner the fewest votes. We find that many more participants do not vote for their most-preferred alternative than theory predicts. We also test whether prompting participants to think about the likely vote distribution before voting affects their own vote. We find that prompting participants does not a...
A simple proof of Andrews's 5F4 evaluation

We give a simple proof of George Andrews’s balanced 5F4 evaluation using two fundamental principles: the nth difference of a polynomial of degree less than n is zero, and a polynomial of degree n that vanishes at n+1 points is identically zero.
Magnetic Field Structure and Stochastic Reconnection in a Partially Ionized Gas

We consider stochastic reconnection in a magnetized, partially ionized medium. Stochastic reconnection is a generic effect that results from field line wandering, in which the speed of reconnection is determined by the ability of ejected plasma to diffuse away from the current sheet along magnetic field lines, rather than by the details of current sheet structure. As in earlier work, in which we dealt with a fully ionized plasma, we consider the limit of weak stochasticity, so that the mean magnetic field energy density is greater than either the turbulent kinetic energy density or the energy density associated with the fluctuating component of the field. For specificity, we consider field line stochasticity generated through a turbulent cascade, which leads us to consider the effect of neutral drag on the turbulent cascade of energy. In a collisionless plasma, neutral particle viscosity and ion-neutral drag will damp midscale turbulent motions, but the power spectrum of the magnetic perturbations extends below the viscous cutoff scale. We give a simple physical picture of the magnetic field structure below this cutoff, consistent with numerical experiments. We provide arguments for the reemergence of the turbulent cascade well below the viscous cutoff scale and derive estimates for field line diffusion on all scales. We note that this explains the persistence of a single power-law form for the turbulent power spectrum of the interstellar medium (ISM), from scales of tens of parsecs down to thousands of kilometers. We find that under typical conditions in the ISM stochastic reconnection speeds are reduced by the presence of neutrals, but by no more than an order of magnitude. However, neutral drag implies a steep dependence on the Mach number of the turbulence. In the dense cores of H2 regions the reconnection speed is probably determined by tearing-mode instabilities.
Arterial calcification: a review of mechanisms, animal models, and the prospects for therapy.

The causes of arterial calcification are beginning to be elucidated. Macrophages, mast cells, and smooth muscle cells are the primary cells implicated in this process. The roles of a variety of bone-related proteins including bone morphogenetic protein-2 (BMP-2), matrix Gla protein (MGP), osteoprotegerin (OPG), osteopontin, and osteonectin in regulating arterial calcification are reviewed. Animals lacking MGP, OPG, smad6, carbonic anhydrase isoenzyme II, fibrillin-1, and klotho gene product develop varying extents of arterial calcification. Hyperlipidemia, vitamin D, nicotine, and warfarin, alone or in various combinations, produce arterial calcification in animal models. MGP has recently been discovered to be an inhibitor of bone morphogenetic protein-2, the principal osteogenic growth factor. Many of the forces that induce arterial calcification may act by disrupting the essential post-translational modification of MGP, allowing BMP-2 to induce mineralization. MGP requires gamma-carboxylation before it is functional, and this process uses vitamin K as an essential cofactor. Vitamin K deficiency, drugs that act as vitamin K antagonists, and oxidant stress are forces that could prevent the formation of GLA residues on MGP. The potential role of arterial apoptosis in calcification is discussed. Potential therapeutic options to limit the rate of arterial calcification are summarized.
Stereoselective synthesis of acetoacetate-derived enol triflates.

A highly stereoselective method for preparing (Z)- and (E)-enol triflates derived from substituted acetoacetate derivatives is described. The salient feature of this methodology is the use of Schotten−Baumann-type conditions to control enolate geometry using either aqueous LiOH (Z-selective) or aqueous (Me)4NOH (E-selective) in combination with triflic anhydride to provide a practical and predictable approach to these valuable substrates.
Enantioselective friedel-crafts alkylations with benzoylhydrazones promoted by a simple strained silacycle reagent.

The enantioselective Friedel−Crafts reaction of electron-rich arenes and heteroarenes with the benzoylhydrazone of isopropyl glyoxylate mediated by a simple chiral silane Lewis acid is described. The reactions are highly practical, as demonstrated by a larger scale (5 g of the hydrazone) reaction in which the recovery of the pseudoephedrine in 99% yield was achieved. A simple model is advanced to explain the observed enantioselectivity.
Functional transformations in AI discovery systems

Abstract The power of scientific discovery systems derives from two main sources: a set of heuristics that determines when to apply a creative operator (an operator for forming new operators and concepts) in a space that is being explored; and a set of creative operators that determines what new operators and concepts will be created for that exploration. This paper is mainly concerned with the second issue. A mechanism called functional transformation (FT) shows promising power in creating new and useful creative operators during exploration. This paper discusses the definition, creation, and application of functional transformations, and describes, as a demonstration of the power of FT, how the system ARE, starting with a small set of creative operations and a small set of heuristics, uses FTs to create all the concepts attained by Lenat's AM system [4], and others as well. Besides showing an alternative way, of Lenat's eurisko [5], to meet the criticisms of too much pre-programmed knowledge [6] that have been leveled against AM, ARE provides a route to discovery systems that are capable of “refreshing” themselves indefinitely by continually creating new operators.
Finite element buckling and postbuckling solutions for multilayered composite panels

Abstract A study is made of the buckling and postbuckling responses of flat, unstiffened composite panels subjected to various combinations of mechanical and thermal loads. The analysis is based on a first-order shear deformation von Karman-type plate theory. A mixed formulation is used with the fundamental unknowns consisting of the strain components, stress resultants and the generalized displacements of the plate. The stability boundary, postbuckling response and the sensitivity coefficients are evaluated. The sensitivity coefficients measure the sensitivity of the buckling and postbuckling responses to variations in the different lamination and material parameters of the panel. Numerical results are presented for both solid panels and panels with central circular cutouts. The results show the effects of the variations in the fiber orientation angles, aspect ratio of the panel, and the hole diameter (for panels with cutouts) on the stability boundary, postbuckling response and sensitivity coefficients.
Nanostructured materials for thermoelectric applications

Recent studies indicate that nanostructuring can be an effective method for increasing the dimensionless thermoelectric figure of merit (ZT) in materials. Most of the enhancement in ZT can be attributed to large reductions in the lattice thermal conductivity due to increased phonon scattering at interfaces. Although significant gains have been reported, much higher ZTs in practical, cost-effective and environmentally benign materials are needed in order for thermoelectrics to become effective for large-scale, wide-spread power and thermal management applications. This review discusses the various synthetic techniques that can be used in the production of bulk scale nanostructured materials. The advantages and disadvantages of each synthetic method are evaluated along with guidelines and goals presented for an ideal thermoelectric material. With proper optimization, some of these techniques hold promise for producing high efficiency devices.
The magnetic field of Neptune

A model is given of the planetary magnetic field of Neptune based on a spherical harmonic analysis of the observations obtained by the Voyager 2. Generalized inverse techniques are used to partially solve a severely underdetermined inverse problem, and the resulting model is nonunique since the observations are limited in spatial distribution. Dipole, quadrupole, and octupole coefficients are estimated independently of other terms, and the parameters are shown to be well constrained by the measurement data. The large-scale features of the magnetic field including dipole tilt, offset, and harmonic content are found to characterize a magnetic field that is similar to that of Uranus. The traits of Neptune's magnetic field are theorized to relate to the 'ice' interior of the planet, and the dynamo-field generation reflects this poorly conducting planet.
Photolytic generation of carbon radicals from barton esters: Recent developments

Abstract O -Acyl derivatives of N -hydroxy-2-thiopyridone can be photolysed with suitable commercial visible-light lamps to give reactions with very short half-lives (down to 20 s) at 0° C or room temperature.
Surface Permanent-Magnet Machine Self-Sensing at Zero and Low Speeds Using Improved Observer for Position, Velocity, and Disturbance Torque Estimation

This paper proposes an improved method for the estimation of position, velocity, and disturbance torque in a surface permanent-magnet (SPM) machine self-sensing (position sensorless) drive that uses high-frequency (HF) voltage injection. SPM machines traditionally do not have enough position-dependent signals because their symmetric rotors result in near-zero spatial saliency. A separate disturbance observer and a saliency-tracking observer with speed-varying bandwidth (BW) tuning are used together to improve the disturbance rejection performance while maintaining the accuracy of self-sensing position and velocity estimation. According to the experimental evaluation, the proposed estimation method can achieve higher BW for the disturbance estimation and decoupling which can increase the stiffness of SPM machine closed-loop self-sensing control. This paper includes experimental comparative evaluation of closed-loop encoder-based versus closed-loop self-sensing-based operation of a SPM machine drive.
Multi-grid calculation of three-dimensional transonic potential flows

A multi-grid algorithm has been developed to speed the iterative convergence of calculations for the transonic potential flow past swept wings and wing-fuselage combinations. The method is based upon a fully-conservative, finite-volume approximation to the steady potential equation which is second-order accurate everywhere in the flow field except near shock waves. The multi-grid scheme is incorporated within the framework of an alternating successive-line-overrelaxation (SLOR) solver of the difference equations. Computed results confirm the second-order accuracy of the scheme, and demonstrate the effectiveness of the multi-grid procedure.
Is there a future for the continued development of the chemistry of small cage C2B4-carborane? A historical perspective

Abstract The organometallic chemistry of the small-cage nido -C 2 B 4 -carborane ligands is unique and offers potential advantages over both the larger-cage C 2 B 9 and cyclopentadienide systems. However, the study of the chemistry of this ligand system has been limited by the difficulties inherent in their large scale preparation. Initially, the carboranes were produced in limited quantities from the high temperature pyrolysis of gas phase alkyne–pentaborane(9) mixtures, usually in the presence of an amine catalyst. Synthetic methods have evolved so that it is now possible to produce multi-gram quantities of the trimethylsilyl-substituted carbons adjacent, nido -2-(SiMe 3 )3-(R)-2,3-C 2 B 4 H 6 (R=SiMe 3 , H, or an alkyl group). Efficient methods have also been developed for the conversion of these compounds into the corresponding carbons apart, nido -2,4-C 2 B 4 -carborane isomers and for changing the cage carbon substituents. One of the greatest assets in fostering the study of these systems was the almost limitless supply of the pentaborane(9) precursor, supplied free-of-charge from an extensive government surplus. That source is no longer available nor is there a commercial source to take its place. These considerations have led us to review the history of the development of the methods used in the preparation of the small cage carboranes and to speculate on the future of the study of these most interesting ligands.
Fermionic topological charge of families of lattice gauge fields

Abstract Topological charge of families of lattice gauge fields is defined fermionically via families index theory for the overlap Dirac operator. Certain obstructions to gauge invariance of the overlap chiral fermion determinant, as well as the lattice analogues of certain obstructions to gauge fixings without the Gribov problem have natural descriptions in this context.
Synthesis and in vitro characterization of a dendrimer-MORF conjugate for amplification pretargeting.

Amplification pretargeting can play an important role in molecular imaging by significantly increasing the accumulation of signal in target tissues. Multiple-step amplification pretargeting offers the potential to greatly improve target localization of effector molecules through the intermediate use of polymers conjugated with multiple copies of complementary oligomers. In this study, PAMAM dendrimer generation 3 (G3) was conjugated with multiple copies of a phosphorodiamidate morpholino (MORF) oligomer. Characterization of the conjugate by native-PAGE and SE-HPLC demonstrated that the conjugation was successful. The average numbers of MORF groups in the G3-MORF conjugate, both attached and accessible to the 99mTc labeled complementary MORF (cMORF), were determined. The antitumor antibody CC49 was conjugated with both MORF and cMORF (collectively (c)MORF) at an average of about one group per molecule. Nine of the 32 carboxyl groups of the dendrimer were modified with MORF, of which 90% were accessible in ...
Reactivity of platinum and palladium α-ketoacyl complexes toward olefins and acetylenes

Abstract The α-ketoacyl complexes trans-M(PPh3)2(Cl)(COCO2R) (M = Pd, R = (CH2)nCHCH2, n = 2, 3, 4, R = (CH2)2CCMe; M = Pt, R = (CH2)nCHCH2, n = 2, 3, 4, R = (CH2)2CCMe) were prepared by treating M(PPh3)4 with ROCOCOCl. Attempts to insert the pendant olefin or acetylene into the α-ketoacyl-to-metal bond through heating failed, since CO deinsertion to form corresponding acyl complexes was predominant. Reaction of [trans-Pt(PPh3)2(NCMe)(COCOR)]BF4 (R = Me, Ph) with norbornylene resulted in the deinsertion of CO from the α-ketoacyl ligand and the formation of [cis-Pt(PPh3)2(C7H10COR)]BF4, an insertion of norbornylene into the corresponding acyl ligand.
Multigrid calculation of subvortices

Multigrid resolution of fine vertex structure in corners and near separation points is obtained by means of a scheme employing local grid refinement. Parallel, vector, and local Reynolds number aspects of the computation are discussed.
Privacy-preserving techniques for location-based services

Recent advances in positioning techniques, small devices, GIS-based services, and ubiquitous connectivity, have enabled a large variety of location-based services able to tailor services according to the location of the individual requiring the service. Location information, however, if on one side is critical for providing customized services, on the other hand, if misused, can lead to privacy breaches. By cross-referencing location information about an individual with other information and by exploiting domain knowledge, an attacker may infer sensitive information about the individual, such as healthcare or financial information. To address such problems, different techniques have been proposed that are based on two main approaches: location cloaking, under which a suitable large region is returned to the service provider instead of the precise user location [1]; location k-anonymization, under which the location of an individual is returned to the service provider only if it is indistinguishable with respect to the location of other k-1 individuals [5, 6]. These techniques have, however, a major drawback in that they do not take into account domain knowledge, and are thus prone to location inference attacks [2]. Given a generalized location of an individual, obtained for example through location cloaking, such an attack exploits the knowledge about the semantics of spatial entities to infer bounds about the location of an individual that are more precise with respect to the generalized location. Another major drawback is that those approaches do not support personalized privacy preferences. We believe that supporting such preferences is crucial in that different individuals have different preferences with respect to which location are considered privacy-sensitive.
Synthesis and binding properties of 2H-1-benzopyran-2 one fluorophore-linked calcium channel antagonist nifedipine (1,4-dihydropyridine) analogs

Nifedipine analogs I, II and III with the 2H-1-benzopyran-2-one (coumarin) fluorophore linked at the 2, 2 and 6 and 4 positions of the dihydropyridine ring were synthesized by the modified Hantzch condensation procedures. Attempts to synthesize dihydropyridine with the fluorophore at position 3 (IV) were unsuccessful.
Sustainable transportation planning on college campuses

In the last decade, campus planners in the US have been struggling to provide access and mobility without destroying campus qualities as distinct communities. The purpose of this paper is to reflect on how college campuses have encouraged a modal shift from cars to other modes, and in particular to bicycling and walking. I report the results of a survey of eight pre-selected bicycle and pedestrian friendly campuses. My argument is that due to their pro-active educational milieu, college campuses are privileged places to communicate sustainability and to help reshape society's transportation patterns.
Decarboxylative Acylation of Arenes with α-Oxocarboxylic Acids via Palladium-Catalyzed C−H Activation

An efficient palladium-catalyzed decarboxylative acylation of unactivated arenes with α-oxocarboxylic acids is reported. This method provides a novel access to aryl ketones.
Thin-sheet-metal bending by laser peen forming with femtosecond laser☆

Abstract A femtosecond laser is a type of ultrashort-pulse laser. Femtosecond laser irradiation induces high-pressure plasma and shock waves at the surface of a target. Under some irradiation conditions, such shock waves are enough to deform the target plastically. Laser peen forming is a type of sheet metal forming using this deformation by shock waves. The author adopted laser peen forming using femtosecond laser for thin-sheet-metal bending. Generally, shock waves induced in air are much smaller than those induced in water, and thus; are unfavorable for plastic deformation. However, the shock waves induced by a femtosecond laser were enough to bend a thin sheet metal even in air. Elastic pre-bending was adopted during the process. Bending angle was increased by applying pre-bending. The effects of laser irradiation conditions on bending efficiency were investigated. The large spot diameter and high fluence improved bending efficiency.
Automorphism groups and derivation algebras of finitely generated vertex operator algebras

We investigate the general structure of the automorphism group and the Lie algebra of derivations of a finitely generated vertex operator algebra. The automorphism group is isomorphic to an algebraic group. Under natural assumptions, the derivation algebra has an invariant bilinear form and the ideal of inner derivations is nonsingular.
Symbolic mathematical computation in a Ph.D. computer science program

This paper describes a graduate course curriculum, currently being taught, in the area of symbolic mathematical computation. The subject area is described and is then followed by a description of the courses. A bibliography for each course is also given. The relationship of the symbolic mathematical computation curriculum to an overall Computer Science curriculum is discussed. Ph.D. theses which have been written are listed and some topics for future research are outlined. The paper ends with a summary of the strengths and weakensses of the curriculum.
Electron-to-tau lepton flavor violation at the Electron-Ion Collider

We analyze the potential sensitivity of a search for e → τ conversion at a proposed electron-ion collider (EIC) facility. To that end, we calculate the cross sections for e → τ events in a leptoquark framework assuming that the leptoquark masses are on the order of several hundred GeV or more. Given present limits on leptoquarks from direct searches at HERA and rare decay processes, an EIC sensitive to 0.1 fb e → τ cross sections could probe previously unexplored regions of parameter space for these lepton flavor violating events (assuming 90 GeV center-of-mass energy and 10 fb^(−1) integrated luminosity). Depending on the species of leptoquark and flavor structure of the couplings, an EIC search could surpass the HERA and rare process sensitivity to e → τ conversion amplitudes by as much as an order of magnitude or more. We also derive updated limits on quark flavor-diagonal LFV leptoquark interactions using the most recent BaBar τ → eγ search. We find that limits from an EIC e → τ search could be competitive with the most recent τ → eγ limit for a subset of the quark flavor-diagonal leptoquark couplings. Using an SU(5) GUT model in which leptoquark couplings are constrained by theneutrino masses and mixing, we illustrate how observable leptoquark-induced e → τ conversion can be consistent with stringent LFV limits imposed by → eγ and e conversion searches.
Effects of the Presence of Organic Listing in Search Advertising

This paper analyzes how the presence of organic listing as a competing information source affects advertisers' sponsored bidding and the equilibrium outcomes in search advertising. We consider a game-theoretic model in which two firms bid for sponsored advertising slots provided by a monopolistic search engine and then compete for consumers in price in the product market. Firms are asymmetrically differentiated in market preference and are given different exposure in organic listing aligned with their market appeal. We identify two aspects of a firm's sponsored bidding incentive, namely, the promotive and the preventive incentives. The presence of organic listing alters firms' sponsored bidding incentives such that the stronger firm has primarily preventive incentive, whereas the weaker has mainly promotive incentive. We show that the preventive incentive decreases and the promotive incentive increases as the difference in firms' market appeal decreases, and as a result, even the weaker firm may outbid the stronger competitor under such a co-listing setting. We further examine how the presence of organic listing affects the equilibrium outcomes by comparing it with a benchmark case in which there is only a sponsored list. We show that the differentiated exposure in the organic list gives the weaker advertiser chances to win a better sponsored position, which improves the overall information structure the search engine provides. As a result, the equilibrium social welfare, sales diversity, and consumer surplus increase. Although the presence of the free exposure from the organic list may reduce advertisers' sponsored bidding incentive per se, the overall effect benefits the search engine's growth in the long run.
A shorter, simpler, stronger proof of the Meshalkin-Hochberg-Hirsch bounds on componentwise antichains

Meshalkin's theorem states that a class of ordered p-partitions of an n-set has at most max(n a1.......ap) members if for each k the kth parts form an antichain. We give a new proof of this and the corresponding LYM inequality due to Hochberg and Hirsch, which is simpler and more general than previous proofs. It extends to a common generalization of Meshalkin's theorem and Erdos's theorem about r-chain-free set families.
Microlens Parallaxes with SIRTF

The Space Infrared Telescope Facility (SIRTF) will drift away from the Earth at ~0.1 AU yr-1. Microlensing events will therefore have different characteristics as seen from the satellite and the Earth. From the difference it is possible in principle to measure , the transverse velocity of the lens projected onto the observer plane. Since has very different values for different populations (disk, halo, Large Magellanic Cloud), such measurements could help identify the location, and hence the nature, of the lenses. I show that the method previously developed by Gould for measuring such satellite parallaxes fails completely in the case of SIRTF: it is overwhelmed by degeneracies that arise from fact that the Earth and satellite observations are in different bandpasses. I develop a new method that allows for observations in different bandpasses and yet removes all degeneracies. The method combines a purely ground-based measurement of the "parallax asymmetry" with a measurement of the delay between the time the event peaks at the Earth and satellite. In effect, the parallax asymmetry determines the component of in the Earth-Sun direction, while the delay time measures the component of in the direction of the Earth's orbit.
A search for acoustic amplitude deficit at the antipodes of sunspots

We present a search for the acoustic oscillation deficit which may exist at the antipodes of sunspots. Dopplergrams from Big Bear Solar Observatory 1988 helioseismology data were selected for five days on which large sunspots were known to be on the unseen hemisphere of the Sun. Acoustic oscillation amplitudes in the antipodal regions of these sunspots were compared with amplitudes in surrounding quiet-Sun regions. We did not detect a statistically significant acoustic amplitude deficit in our data. Our results indicate that the amplitude deficit at the sunspot antipodal points is limited to no more than 3% of the acoustic amplitude in the region, for solar oscillation modes of spherical harmonic degree l ≲ 200. We conclude that no strong acoustic deficit exists at the antipodes of sunspots. A more sensitive search, requiring more elaborate observations than we have performed, would be desirable in order to determine if a weak acoustic amplitude deficit exists at some level at the antipodes of sunspots, perhaps at higher spatial frequencies of oscillation. The noise level in any signals detected by such observations would probably limit their usefulness as seismic probes. However, information on the lifetimes of solar oscillation modes can be deduced even if no acoustic amplitude deficit is detected.
A latitudinal survey of mesospheric and upper stratospheric water vapor

As part of the LAtitudinal DIstribution of Middle Atmosphere Structure (LADIMAS) campaign, measurements of mesospheric and upper stratospheric water vapor concentration were made over a latitudinal range from 53 N to 63 S. The 22-GHz emission line of water vapor was observed by a new, portable, cryogenically cooled microwave radiometer that was carried on board the German research vessel Polarstern as it sailed from Bremerhaven, Germany, to the Antarctic during November and December, 1991. Water vapor profiles were obtained at approximately 5 deg latitude intervals for an altitude range of 40 to 80 km.
Intelligent cruise control systems and traffic flow stability

Abstract There are two kinds of stability associated with traffic flow problems – string stability (or car-following stability) and traffic flow stability. We provide a clear distinction between traffic flow stability and string stability, and such a distinction has not been recognized in the literature, thus far. String stability is stability with respect to intervehicular spacing; intuitively, it ensures the knowledge of the position and velocity of every vehicle in the traffic, within reasonable bounds of error, from the knowledge of the position and velocity of a vehicle in the traffic. String stability is analyzed without adding vehicles to or removing vehicles from the traffic. On the other hand, traffic flow stability deals with the evolution of traffic velocity and density in response to the addition and/or removal of vehicles from the flow. Traffic flow stability can be guaranteed only if the velocity and density solutions of the coupled set of equations is stable, i.e., only if stability with respect to automatic vehicle following and stability with respect to density evolution is guaranteed. Therefore, the flow stability and critical capacity of any section of a highway is dependent not only on the vehicle following control laws and the information used in their synthesis, but also on the spacing policy employed by the control system. Such a dependence has practical consequences in the choice of a spacing policy for adaptive cruise control laws and on the stability of the traffic flow consisting of vehicles equipped with adaptive cruise control features on the existing and future highways. This critical dependence is the subject of investigation here.
Progressive Supranuclear Palsy

Progressive supranuclear palsy is a disorder of tau protein aggregation. Its clinical spectrum is now known to be wider than originally described, with a phenotype resembling Parkinson disease accounting for a third of cases. However, at least half of the patients with PSP exhibit the classic bradykinesia with disproportionate postural instability, erect posture with nuchal rigidity, frontal behavioral and cognitive changes, vertical gaze palsy, and other disabling brainstem deficits. Nonmendelian genetic risk factors exist, but PSP is almost entirely sporadic, with a prevalence of five to six persons per 100,000, mean onset age of 63, and median survival of 7 years. Clinical diagnostic criteria with excellent specificity and a clinical rating scale sensitive to progression are available. Diagnosis remains clinical, although magnetic resonance imaging and cerebrospinal fluid measures are showing promise as early-stage screening tools. Multiple candidate neuroprotective medications have proven ineffective to date. Treatment remains supportive, although coenzyme Q-10 has shown preliminary symptomatic efficacy and levodopa may provide transient, modest benefit.
Vitamin D C-22 aldehydes. New key intermediates for the synthesis of side chain modified vitamin D analogues

Abstract Vitamin D C-22 aldehyde and 1α-hydroxyvitamin D C-22 aldehyde were efficiently synthesized starting from the readily available 22,23-bisnorcholenic acid. The usefulness of the compounds as common intermediates for the synthesis of side chain modified analogues of vitamins D2 and D3 has been demonstrated.
19-electron intermediates in the ligand substitution of CpW(CO)3* with a Lewis base.

Odd electron species are important intermediates in organometallic chemistry, participating in a variety of catalytic and electron-transfer reactions which produce stable even-electron products. While electron deficient 17-electron (17e) radicals have been well characterized, the possible existence of short-lived 19-electron (19e) radicals has been a subject of continuing investigation. 19e radicals have been postulated as intermediates in the photochemical ligand substitution and disproportionation reactions of organometallic dimers containing a single metal-metal bond, yet the reactions of these intermediates on diffusion-limited time scales (ns-{micro}s) have never been directly observed. This study resolves the 19e dynamics in the ligand substitution of 17e radicals CpW(CO){sub 3}{sup {sm_bullet}} (Cp = C{sub 5}H{sub 5}) with the Lewis base P(OMe){sub 3}, providing the first complete description 19e reactivity.
SPONTANEOUS BREAKDOWN OF CONFORMAL AND CHIRAL INVARIANCE.

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included by .pdf document. We discuss the implications of a theory in which scale and chiral invariance are spontaneously broken, and the dilaton [...] appears as a mixture of the two isoscalar members of the scalar nonet. From standard assumptions for the conformal properties of the axial-vector current, we predict the ratio of the [...] and [...] coupling constants, and test the hypothesis of f-dominance. At first, we neglect the effects of scale violation. Then, the calculated width of the dilaton, [...], appears to exceed the limit given by the Adler-Weisberger sum rule for [...] scattering, while f-dominance seems to work. Using the method of collinear dispersion relations, we estimate scalebreaking effects, which are found to be large. In the real world, our result for [...] agrees with other expectations, both experimental and theoretical. However, the spin-2 gravitational radius of the pion is found to be double the prediction of f-dominance. This is consistent with experimental indications that f-dominance fails. We discuss meson-baryon scattering and its relation to parameters measuring the breaking of chiral symmetry in the energy density. Our interpretation of a recent result of Cheng and Dashen is that scale invariance is spontaneously broken, and chiral SU(2) x SU(2) is a much better summetry than SU(3). By requiring consistency, with a sum rule of von Hippel and Kim, we find that data for [...] scattering are not consistent with the dimension of the chiral-violating scalar being -1.
Chemical, Enzymatic and Structural Studies in Molecular Glycobiology

Carbohydrates are increasingly appreciated for their critical roles in biological functions. Driving these studies addressing the molecular basis of carbohydrate-mediated events is the availability of natural and unnatural carbohydrates. Recently, new methods of enzymatic synthesis have been developed that now afford rapid access to complex, structurally diverse oligosaccharides on large scales. This methodology has been essential to gaining insight into the molecular details of important carbohydrate recognition phenomena that are associated with many signaling processes. This review summarizes recent chemical studies examining selectin/sialyl Lewisx binding, a key event in inflammation and metastasis, and describes the development of carbohydrate mimetics that may offer leads to new therapeutic agents. In addition, combinatorial synthesis has been used to prepare carbohydrate mimetics to neomycin B, an aminoglycoside that binds RNA involved in HIV infection, and chemoenzymatic methodology has been applied to the design and synthesis of mechanism-based inhibitors of glycoprocessing enzymes.
Kinetics of the reaction of phenylchlorocarbene with an azabicyclobutane

Abstract The reaction of phenylchlorocarbene with 3-ethyl-1-azabicyclo[1.1.0]-butane (3) in pentane at 25 °C occurs with a rate constant of 3.2 × 108M−1s−1, most likely via ylide 4.
Explosive welding of aluminum to aluminum: analysis, computations and experiments

Abstract 6061 T0 aluminum alloy was joined to 6061 T0 aluminum alloy by explosive welding. This is a process in which the controlled energy of a detonating explosive is used to create a metallic bond between two similar or dissimilar materials. The welding conditions were tailored to produce both wavy and straight interfaces. A three-pronged study was used to establish the conditions for straight weld formation: (a) analytical calculation of the domain of weldability, in which the Szecket–Mayseless (Mater. Sci. Eng. 57 (1983) 149) criterion was successfully used; (b) characterization of the explosive welding experiments carried out under different conditions, and (c) 2D finite differences simulation of these tests using the explicit Eulerian hydrocode Raven with a Johnson–Cook constitutive equation for the Al alloy. The numerical simulation and the analytical calculations confirm the experimental results and explain the difficulties met for obtaining a continuous straight interface along the entire weld.
A cognitive compensation mechanism for deformable antennas

This work presents the design, theory, and measurement of a linearly polarized microstrip patch antenna with a substrate-integrated compensation mechanism to mitigate the detuning effects from a physical deformation (e.g., bending and twisting). In particular, we investigate the ability of an antenna to maintain its impedance bandwidth as it bends sharply through the center (from flat up to 90° pivoted about the ground plane). Compensation for this bending occurs through the displacement of electromagnetically functionalized colloidal dispersions (EFCDs) in a substrate-embedded capillary. By replacing a high permittivity EFCD with a low permittivity EFCD during bending this provides a net length reduction to oppose the length extension (stretching) from the bending action. Stability of the 2:1 VSWR (matched impedance) bandwidth has been examined numerically across the entire range of bending, and examined experimentally using fixed-bend patch antennas on 4 mm thick isiocane foam substrates (one flat patch and one patch bent to 90°) to demonstrate this concept. A deformable patch antenna fabricated on a silicone substrate with conductive elastomers has also been examined and trends between simulated and measured results are in good agreement.
ON ASYMPTOTICALLY OPTIMAL TESTS UNDER LOSS OF IDENTIFIABILITY IN SEMIPARAMETRIC MODELS

We consider tests of hypotheses when the parameters are not identifiable under the null in semiparametric models, where regularity conditions for profile likelihood theory fail. Exponential average tests based on integrated profile likelihood are constructed and shown to be asymptotically optimal under a weighted average power criterion with respect to a prior on the nonidentifiable aspect of the model. These results extend existing results for parametric models, which involve more restrictive assumptions on the form of the alternative than do our results. Moreover, the proposed tests accommodate models with infinite dimensional nuisance parameters which either may not be identifiable or may not be estimable at the usual parametric rate. Examples include tests of the presence of a change-point in the Cox model with current status data and tests of regression parameters in odds-rate models with right censored data. Optimal tests have not previously been studied for these scenarios. We study the asymptotic distribution of the proposed tests under the null, fixed contiguous alternatives and random contiguous alternatives. We also propose a weighted bootstrap procedure for computing the critical values of the test statistics. The optimal tests perform well in simulation studies, where they may exhibit improved power over alternative tests.
The Interstellar N/O Abundance Ratio: Evidence for Local Infall?

Sensitive measurements of the interstellar gas-phase oxygen abundance have revealed a slight oxygen deficiency (~15%) toward stars within 500 pc of the Sun as compared to more distant sight lines. Recent FUSE observations of the interstellar gas-phase nitrogen abundance indicate larger variations, but no trends with distance were reported due to the significant measurement uncertainties for many sight lines. By considering only the highest quality (≥5 σ) N/O abundance measurements, we find an intriguing trend in the interstellar N/O ratio with distance. Toward the seven stars within ~500 pc of the Sun, the weighted mean N/O ratio is 0.217 ± 0.011, while for the six stars farther away the weighted mean value (N/O = 0.142 ± 0.008) is curiously consistent with the current solar value (N/O = 0.138). It is difficult to imagine a scenario invoking environmental (e.g., dust depletion or ionization) variations alone that explains this abundance anomaly. Is the enhanced nitrogen abundance localized to the solar neighborhood or evidence of a more widespread phenomenon? If it is localized, then recent infall of low-metallicity gas in the solar neighborhood may be the best explanation. Otherwise, the N/O variations may be best explained by large-scale differences in the interstellar mixing processes for AGB stars and Type II supernovae.
Building new markets: a comparison of the Russian and American credit card markets

Based, in part, on original fieldwork in Moscow, Russia, in 1998, 1999 and 2004, this paper focuses on two markets at their conception points-the American credit card market of the late 1950s and 1960s and the Russian credit card market of the 1990s. Emerging credit card markets need to solve two problems: the problem of uncertainty inherent in lending and the complementarity problem of simultaneously attracting merchants and cardholders. American banks jump-started the market by mailing unsolicited cards to thousands of unsuspecting and unscreened individuals. This resulted in staggering losses, but helped to attract merchants. American banks eventually solved the uncertainty problem through formal institutional means: they shared account information with third parties (credit bureaus) and based pre-screening on the calculation of risk, which made bank-customer relationships completely impersonal. The dominant way to disseminate cards in Russia is through payroll agreements with enterprises, whereby the employees are issued cards secured by their salaries directly deposited to the bank. Not only does the rapid increase of cardholders attract merchants, but payroll projects also solve the uncertainty problem through two-stage embeddedness: banks rely on employing organizations to mediate their relations with cardholders. As a result of dissimilar solutions to the uncertainty and complementarity problems, the structures of Russian and American credit card markets differ as well.
Neuroimages as evidence in a mens rea defense: No impact.

Recent developments in the neuropsychology of criminal behavior have given rise to concerns that neuroimaging evidence (such as MRI and functional MRI [fMRI] images) could unduly influence jurors. Across four experiments, a nationally representative sample of 1,476 jury-eligible participants evaluated written summaries of criminal cases in which expert testimony was presented in support of a mental disorder as exculpatory. The evidence varied in the extent to which it presented neuroscientific explanations and neuroimages in support of the expert’s conclusion. Despite suggestive findings from previous research, we found no evidence that neuroimagery affected jurors’ judgments (verdicts, sentence recom-mendations, judgments of the defendant’s culpability) over and above verbal neuroscience - based testimony. A meta-analysis of our four experiments confirmed these findings. In addition, we found that neuroscientific evidence was more effective than clinical psycho- logical evidence in persuading jurors that the defendant’s disorder reduced his capacity to control his actions, although this effect did not translate into differences in verdicts.
Morse homology, tropical geometry, and homological mirror symmetry for toric varieties

Given a smooth projective toric variety X, we construct an A∞ category of Lagrangians with boundary on a level set of the Landau–Ginzburg mirror of X. We prove that this category is quasi-equivalent to the DG category of line bundles on X.
Reliable dissolve detection

Automatic shot boundary detection has been an active research area for nearly a decade and has led to high performance detection algorithms for hard cuts, fades and wipes. Reliable dissolve detection, however, is still an unsolved problem. In this paper, we present the first robust and reliable dissolve detection system. A detection rate of 69 percent was achieved while reducing the false alarm rate to an acceptable level of 68 percent on a test video set for which so far the best reported detection and false alarm rate had been 57 percent and 185 percent, respectively. In addition, the temporal extent of the dissolves are estimated by a multi-resolution detection approach. The three core ideas of our novel approach are firstly the creation of a dissolve synthesizer capable of creating in principle an infinite number of dissolve examples of any duration form a video database of raw video footage, secondly tow new features for capturing the characteristics of dissolves, and thirdly, the exploitation of machine learning ideas for reliable object detection such as the boostrap-method to improve the set of non-dissolve examples and the search at multiple resolutions as well as the usage of machine learning algorithms such as neural networks, support-vector machines and linear vector quantizer.
Two-color two-photon excitation of fluorescence

We report the observation of two-photon excitation of an organic fluorophore with two different wavelengths, a phenomenon we refer to as two-color two-photon (2C2P) excitation. Ultraviolet emission of p-terphenyl at 340 nm was observed when the sample was illuminated with both 375 and 750 nm pulses from a picosecond dye laser. The emission of p-terphenyl was about 100-fold and more than 1000-fold less for illumination at only 375 or 750 nm, respectively. Observation of the 2C2P signal required temporal and spatial overlap of the 375 and 750 nm pulses. The amplitude of the signal depended on the polarization of each beam. 2C2P excitation can have applications in fluorescence microscopy and elsewhere when spatially localized excitation is desirable.
Gravity Dual for Cyclic Renormalization Group Flow Without Conformal Invariance

We construct a gravity dual for scale invariant but non-conformal field theories with a cyclic renormalization group flow. A slight modification of our construction gives a gravity dual of discretely scale invariant field theories. The underlying gravitational theory breaks the null energy condition.
Virtual knots and links

This paper is an introduction to the subject of virtual knot theory and presents a discussion of some new specific theorems about virtual knots. The new results are as follows: Using a 3-dimensional topology approach, we prove that if a connected sum of two virtual knots K 1 and K 2 is trivial, then so are both K 1 and K 2. We establish an algorithm for recognizing virtual links that is based on the Haken-Matveev technique.