cssi/SciSciGPT-SciSciNet huggingface dataset:
High-Altitude Particle Acceleration and Radiation in Pulsar Slot Gaps

We explore the pulsar slot gap (SG) electrodynamics up to very high altitudes, where for most relatively rapidly rotating pulsars both the standard small-angle approximation and the assumption that the magnetic field lines are ideal stream lines break down. We address the importance of the electrodynamic conditions at the SG boundaries and the occurrence of a steady-state drift of charged particles across the SG field lines at very high altitudes. These boundary conditions and the cross-field particle motion determine the asymptotic behavior of the scalar potential at all radii from the polar cap (PC) to near the light cylinder. As a result, we demonstrate that the steady-state accelerating electric field, E(sub ll), must approach a small and constant value at high altitude above the PC. This E(sub ll) is capable of maintaining electrons moving with high Lorentz factors (approx. a few x 10(exp 7)) and emitting curvature gamma-ray photons up to nearly the light cylinder. By numerical simulations, we show that primary electrons accelerating from the PC surface to high altitude in the SG along the outer edge of the open field region will form caustic emission patterns on the trailing dipole field lines. Acceleration and emission in such an extended SG may form the physical basis of a model that can successfully reproduce some pulsar high-energy light curves.
On the local structure of doubly laced crystals

Let g be a Lie algebra all of whose regular subalgebras of rank 2 are type A"1xA"1, A"2, or C"2, and let B be a crystal graph corresponding to a representation of g. We explicitly describe the local structure of B, confirming a conjecture of Stembridge.
On simple and creative sets in NP

Abstract Two structurally defined types of NP-sets are studied. k-Simple sets are defined and shown to exist in NP. Other properties of these sets are investigated. k-Creative sets, as previously defined by Joseph and Young (1985), are next considered. A new condition is given which implies that a set is k-creative. Several previously considered NP-complete sets are proved to be k-creative.
Ncore: architecture and implementation of a flexible, collaborative digital library

NCore is an open source architecture and software platform for creating flexible, collaborative digital libraries. NCore was developed by the National Science Digital Library (NSDL) project, and it serves as the central technical infrastructure for NSDL. NCore consists of a central Fedora-based digital repository, a specific data model, an API, and a set of backend services and frontend tools that create a new model for collaborative, contributory digital libraries. This paper describes NCore, presents and analyzes its architecture, tools and services; and reports on the experience of NSDL in building and operating a major digital library on it over the past year and the experience of the Digital Library for Earth Systems Education in porting their existing digital library and tools to the NCore platform.
Vortices in spatially inhomogeneous superfluids

We study vortices in a radially inhomogeneous superfluid, as realized by a trapped degenerate Bose gas in a uniaxially symmetric potential. We show that, in contrast to a homogeneous superfluid, an off-axis vortex corresponds to an anisotropic superflow whose profile strongly depends on the distance to the trap axis. One consequence of this superflow anisotropy is vortex precession about the trap axis in the absence of an imposed rotation. In the complementary regime of a finite prescribed rotation, we compute the minimum-energy vortex density, showing that in the rapid-rotation limit it is extremely uniform, despite a strongly inhomogeneous (nearly) Thomas-Fermi condensate density ${\ensuremath{\rho}}_{s}(r)$. The weak radially dependent contribution $[\ensuremath{\propto}{\ensuremath{\nabla}}^{2}\phantom{\rule{0.2em}{0ex}}\mathrm{ln}\phantom{\rule{0.2em}{0ex}}{\ensuremath{\rho}}_{s}(r)]$ to the vortex distribution, that vanishes with the number of vortices ${N}_{v}$ as $1∕{N}_{v}$, arises from the interplay between vortex quantum discreteness (namely their inability to faithfully support the imposed rigid-body rotation) and the inhomogeneous superfluid density. This leads to an enhancement of the vortex density at the center of a typical concave trap, a prediction that is in quantitative agreement with recent experiments. One striking consequence of the inhomogeneous vortex distribution is an azimuthally directed, radially shearing superflow.
One-electron and two-electron transfers in electrochemistry and homogeneous solution reactions.

Certainly one of the first topics to come to mind on seeing the term “molecular electrochemistry” is the subject of electron-transfer reactions. In most cases, a multistep electrode reaction will be initiated by an electron-transfer step, either gain or loss of an electron. The product of that reaction will subsequently participate in chemical and electrochemical reactions leading finally to the end product of the reaction. Thus, an understanding of electron transfer is basic to the entire field of molecular electrochemistry. For a majority of electrode reactions of organic and organometallic species, only a single oxidation or reduction is encountered within the accessible potential range of the solvent/electrolyte medium that is chosen. This is often because that single electron transfer is situated fairly close to the solvent breakdown potential so that second or subsequent electron transfers are masked. However, in many instances two separate electron-transfer reactions can be detected with the normal pattern being that addition or removal of the second electron occurs with greater difficulty than the first. In many of these cases, but not all, the molecule contains two identical electroactive groups, an example being the reduction of dinitroaromatics such as 1,4-dinitrobenzene.
Correlation between the charged kaon ratio and the baryon phase-space density in heavy-ion collisions

Abstract It is found that the average baryon phase-space density obtained from the ratio of deuteron to proton yields is nearly constant over centrality in Au+Au collisions at the AGS. The finding offers an explanation for the puzzling centrality independence of the ratio of charged kaon total yields. The correlation between the charged kaon ratio and the average baryon phase-space density is studied for central heavy-ion collisions of various systems over a wide range of beam energy. It is found that the charged kaon ratio and the average baryon phase-space density both increase with decreasing beam energy, and are strongly correlated. Such study may provide a new approach to search for medium effects on the kaon mass.
A Numerical Study on the Effect of CO Addition on Flame Temperature and NO Formation in Counterflow CH4/Air Diffusion Flames

A numerical study was carried out to understand the effect of carbon monoxide enrichment on flame temperature and NO formation in counterflow methane/air diffusion flames. Detailed chemistry and complex thermal and transport properties were employed. The results indicate that when carbon monoxide is added to th e fuel, both flame temperature and NO formation rate are changed due to the variations in adiabatic flame temperature, fuel Lewis number and chemical reaction. The combination effects of three factors result in the different characteristics of fl ame temperature and NO formation at various strain rates, when carbon monoxide is added. At a low strain rate, the addition of carbon monoxide causes a monotonic decrease in flame temperature and peak NO concentration. However, NO emission index first slightly increases, and then decreases. When the value of strain rate is moderate, the addition of carbon monoxide has negligible effect on flame temperature and leads to a slight increase in both peak NO concentration and NO emission index, until the fraction of carbon monoxide reaches about 0.7. Then with a further increase in the fraction of added carbon monoxide, all three quantities quickly decrease. When strain rate is increased to a value close to the strain extinction limit of pure methane/air diffusion flame, the additio n of carbon monoxide causes increase in flame temperature and NO formation rate, until a critical carbon monoxide fraction is reached. After the critical fraction, the further addition of carbon monoxide leads to decrease in both flame temperature and NO formation rate. The paper also analyzed the variation in the mechanism of NO formation, when carbon monoxide is added.
The relationship between Saturn kilometric radiation and the solar wind

Voyager spacecraft radio, interplanetary plasma, and interplanetary magnetic field data are used to show that large amplitude fluctuations in the power generated by the Saturn kilometric radio emission are best correlated with solar wind ram pressure variation. In all, thirteen solar wind quantities previously found important in driving terrestrial magnetospheric substorms and other auroral processes were examined for evidence of correlations with the Saturn radio emission. The results are consistent with hydromagnetic wave or eddy diffusion processes driven by large scale solar wind pressure changes at Saturn's dayside magnetopause.
Adventitial expression of recombinant endothelial nitric oxide synthase gene reverses vasoconstrictor effect of endothelin-1.

The present study was designed to determine the effect of recombinant endothelial nitric oxide synthase (eNOS) gene expression on reactivity of canine basilar arteries to endothelin-1 (ET-1). Experiments were performed ex vivo. The arteries were exposed (30 minutes at 37°C) to adenoviral vectors encoding eNOS gene (AdCMVeNOS) or β-galactosidase reporter gene (AdCMVβ-Gal). Twenty-four hours after transduction, transgene expression was evident mainly in the vascular adventitia. Rings of control (nontransduced), AdCMVβ-Gal- and AdCMVeNOS-transduced arteries with and without endothelium were suspended for isometric tension recording. Levels of guanosine 3′,5′-cyclic monophosphate (cGMP) were measured by radioimmunoassay. During contractions to uridine 5′-triphosphate, ET-1 (10−10 to 3×10−9 mol/L) caused further increase in tension in control and AdCMVβ-Gal-transduced arteries. In contrast, ET-1 caused concentration-dependent relaxations of AdCMVeNOS-transduced arteries. The relaxations to ET-1 in AdCMVeNOS-transduced arteries were endothelium-independent. They were abolished by NG-nitro-L-arginine methyl ester or by chemical treatment of adventitia with paraformaldehyde before gene transfer. ET-1 (10−9 mol/L) significantly increased intracellular cGMP levels in AdCMVeNOS-transduced arteries without endothelium. In arteries transduced with AdCMVeNOS, higher concentrations (10−9 to 3×10−8 mol/L) of ET-2 also caused relaxations, whereas ET-3 and sarafotoxin, a selective ETB receptor agonist, did not produce any relaxations. The relaxations to ET-1 in AdCMVeNOS-transduced arteries were strongly reduced by BQ-123 (10−7 mol/L), an ETA receptor antagonist, but were not affected by BQ-788 (3×10−7 mol/L), an ETB receptor antagonist. These results suggest that genetically modified adventitia can produce nitric oxide and cause relaxations in response to ET-1 via activation of ETA receptors. Our findings support a novel concept that successful transfer and expression of recombinant eNOS gene can lead to a qualitative change in responsiveness to vasoconstrictor substances.
Swimming with ShARCS: comparison of on-sky sensitivity with model predictions for ShaneAO on the Lick Observatory 3-meter telescope

The Lick Observatory's Shane 3-meter telescope has been upgraded with a new infrared instrument (ShARCS - Shane Adaptive optics infraRed Camera and Spectrograph) and dual-deformable mirror adaptive optics (AO) system (ShaneAO). We present first-light measurements of imaging sensitivity in the Ks band. We compare mea- sured results to predicted signal-to-noise ratio and magnitude limits from modeling the emissivity and throughput of ShaneAO and ShARCS. The model was validated by comparing its results to the Keck telescope adaptive optics system model and then by estimating the sky background and limiting magnitudes for IRCAL, the pre- vious infra-red detector on the Shane telescope, and comparing to measured, published results. We predict that the ShaneAO system will measure lower sky backgrounds and achieve 20% higher throughput across the JHK bands despite having more optical surfaces than the current system. It will enable imaging of fainter objects (by 1-2 magnitudes) and will be faster to reach a fiducial signal-to-noise ratio by a factor of 10-13. We highlight the improvements in performance over the previous AO system and its camera, IRCAL.
Macroeconomic Fragility and Exchange Rate Vulnerability: A Cautionary Record of Transition Economies

The interaction between the exchange rate regime and macroeconomic stabilization in several transition economies during 1990–1996 was influenced by the persistence of high inflation rates and the initial disequilibrium between the highly undervalued nominal exchange rates in relation to their purchasing power parity estimates. Policymakers generally adopted the flexible (nominal) exchange rate regimes for manipulating real exchange rates with a view to correcting the exchange rate disequilibrium and conveying inflation control signals. The rates of real appreciation were higher in the earlier years of high inflation rates. By 1996, lower inflation rates required less currency appreciations thereby reducing the negative impact of the latter on trade competitiveness. However, the persistence of unwarranted interest rate differentials, a consequence of the domination of monetary control over prudent fiscal management, and the associated inflows of foreign funds put an upward pressure on exchange rates exacerbating trade competitiveness. The transition record suggests that innovative exchange rate arrangements can provide only a brief interval during which sound fiscal discipline needs to be put in place for controlling inflation.J. Comp. Econom.,December 1998, 26(4), pp. 621–641. Columbia University, New York, New York 10027.
Laser-Induced Fluorescence-Line-Narrowing Spectroscopy of Glass: Nd

Laser-induced fluorescence line narrowing has been studied in a series of samples of glass: Nd. The features of the nonresonant-excitation technique are described, and the results are discussed in terms of the known spectroscopic properties of the glass: Nd system. The concentration and temperature dependence of the line narrowing have been studied, and the spectral diffusion that is observed is analyzed in terms of resonant ion-ion energy transfer.
Broad spectrum catalytic system for the deep oxidation of toxic organics in aqueous medium using dioxygen as the oxidant

In water, metallic palladium was found to catalyze the deep oxidation of a wide variety of functional organics by dioxygen at 80−90 °C in the presence of carbon monoxide or dihydrogen. Several classes of organic compounds were examined: benzene, phenol and substituted phenols, nitro and halo organics, organophosphorus, and organosulfur compounds. In every case, deep oxidation to carbon monoxide, carbon dioxide, and water occurred in high yields, resulting in up to several hundred turnovers over a 24 h period. For substrates susceptible to hydrogenation, the conversions were generally higher with dihydrogen than with carbon monoxide. For organophosphorus compounds, the system presents the first examples of catalytic cleavage of phosphorus−alkyl bonds.
Pentadienyl Complexes of the Group 4 Transition Metals

Publisher Summary This chapter focuses on the advances made in the pentadienyl chemistry of three elements—namely, titanium, zirconium, and hafnium. As group 4 transition metals, these elements generate a rich coupling chemistry, and as their metallocenes also they have proven to be remarkably unique. The chapter describes some of the most commonly used pentadienyl ligands as illustrated in a chart. In general, a numbering scheme is utilized in which the dienyl termini are defined as C1 and C5, with C2–C4 appearing between C1 and C5. Formally, any charge delocalized over the dienyl fragment can be shared by C1, C3, and C5, leaving C2 and C4 uncharged. The metals themselves play a further role by promoting coupling reactions between unsaturated organic molecules and pentadienyl ligands, much as had already been observed for early metal diene complexes. A number of open and half-open titanocenes, zirconocenes, and hafnocenes have been reported to yield catalysts for the hydrogenation of unsaturated polymers such as polybutadiene. The hydrogenations are carried out in solution phase, and generally are very efficient (84–89%). In addition, the chapter discusses reactions in which pentadienyl ligands are altered, as may occur via a coupling reaction, and applications of metal pentadienyl compounds in materials and catalytic processes.
Electrical Breakdown in Thin Gate and Tunneling Oxides

The breakdown of thin oxides (7.9-32 nm) subjected to high-field current injection is investigated in this study. The physical mechanism of breakdown is found to be localized field enhancement at the cathode interface due to hole trapping. The source of this hole trapping is believed to be impact ionization in the SiO/sub 2/. A quantitative model for oxide breakdown based on impact ionization and hole trapping at the cathode is presented and shown to agree well with the experimental J - t and time-to-breakdown, (t/sub BD/) results. We observe that log t/sub BD/ varies linearly with 1/E rather than with E as commonly assumed. The field acceleration factor, i.e., the slope of the log t/sub BD/ versus 1/E plot, is approximately 140 decades per centimeter per megavolt for the 7.9 nm oxide, with approximately 25 percent of this coming from the field dependence of the impact ionization coefficient and the remainder from the Fowler-Nordheim current dependence on 1/E. Based on this model, oxide wearout performance might be improved by process changes that reduce interface hole trapping, such as radiation-hard processing, in addition to the reduction of particulate contamination and crystal defects.
Getting Around When You’re Just Getting By: Transportation Survival Strategies of the Poor

Researchers argue that transportation expenditures impose a heavy burden on low-income households, many of whom experience difficulty managing their travel costs. However, relatively little research explores how low-income households manage their mobility needs. To address this issue, this study uses qualitative data from interviews with 73 low-income people living in and around San Jose, California. The interviews reveal the resiliency of low-income families in creatively managing their transportation costs. However, the transportation survival strategies of the poor can come at a high price—fewer miles traveled and, therefore, reduced access to opportunities that may lift them out of poverty.
Use of polarization to separate on-axis scattered and unscattered light in red blood cells

The separation of on-axis scattered and unscattered transmission through turbid media has been a difficult experimental task in recent years. This study suggests the use of a polarimeter to filter out the contribution of scattered light to the net on-axis transmission. Red blood cells (RBC) were used to produce the scattering effect. The scattering level was varied by: (1) altering the distance of the detector from the sample, (2) using erythrocytes from three different species, e.g., the dog, goat, and human, which are know to have different RBC sizes, and (3) allowing the RBCs from each species to shrink and swell osmotically. An He-Ne laser was used as the source of the radiation so that data were obtained at a wavelength in the spectral region used in oximetry and hemoglobinometry. In each case, the difference in the scattering cross sections obtained for each sample, with and without polarization filtering, gave us a measure of the filtered scattered light. The results obtained were in close agreement with the expected contribution of scattered radiation to the net axial transmission. This method may be used effectively for all studies involving measurements of on-axis transmission through turbid media, such as biological tissue.
Continuing Education for Media, Library, and Information Specialists

Considerable thought is being given today to the continuing education of media, library, and information specialists for an integrated and communicative profession. The traditional patterns of inte...
Fock Space Representations of the Algebra of Diffeomorphisms of the n-TORUS

As a first step in the construction of quantum field theories invariant under the group of diffeomorphisms, we obtain Fock space representations of the algebra of vector fields of the n-torus. These representations have the novel feature of being carried by bilinear forms rather than operators. Nevertheless all the usual manipulations can be defined via a suitable regularization procedure. Our approach is a generalization of Kac-Peterson’s method for Diff(S1) which allows us to explicitly construct “quantum fields” transforming as “classical” tensors.
The effect of strength training on control of force in older men and women.

Background and aims: Age-related structural alterations in motor units and consequential functional manifestations are asserted to underlie the decline in the ability to finely grade, or control, muscular force in upper extremity musculature of older adults. Functional activities requiring appropriately graded muscular action, such as control of balance, may therefore be negatively affected by these changes. Recent investigations of smaller intrinsic hand muscles have suggested that strength training may attenuate the normal age-related decrease in strength and control of force resulting in increased strength and control. The effects of strength training on the larger, more powerful, anti-gravity muscle of the quadriceps, where age-related changes are noted earlier, are unknown. Thus, the purpose of this study was to assess the effects of 12 weeks of high intensity strength training on strength and the ability to control muscular force in untrained older adults. Methods: Twenty-two subjects aged 59–83 years (11 males, 11 females) were compared to 5 untrained, age-matched controls 58–76 years of age (3 females, 2 males). Maximal isometric knee extensor strength and control of force at 30, 60, and 90% of maximum were measured at 0, 6, and 12 weeks. Results: Significant increases in quadriceps strength were noted in the exercise group but neither group showed a change in the ability to control sub-maximal forces. Conclusions: These findings suggest that high intensity strength training may be efficacious for improving strength but does not improve the ability to control sub-maximal isometric forces.
Single-wall carbon nanotube coating on a pyroelectric detector.

Carbon single-wall nanotubes (SWNTs) are studied as the thermal-absorption coating on a large area pyroelectric detector. The SWNTs were produced by a laser vaporization method and dispersed onto the detector surface by use of a simple airbrush technique. The detector was based on a 1-cm-diameter, 60-μm-thick lithium tantalate disk having nickel electrodes. We report the spectral responsivity of the detector ranging from 600 to 1800 nm, as well as the spatial and directional uniformity at 850 nm. Using Drude and Lorentzian dielectric functions and an effective medium approximation to obtain the indices of refraction of semiconductor and metallic SWNTs, we compared the expected theoretical relative responsivity for the two types of tube with the measured relative responsivity of the detector. Values of thermal conductivity, specific heat, and damage threshold obtained from the literature are compared with properties of alternatives for thermal coatings such as gold-black and carbon-based paint.
ELEMENT DISTRIBUTIONS IN THE CRAB NEBULA

Images of the Crab Nebula have been obtained through custom interference filters that transmit emission from the expanding supernova remnant in He II λ4686, Hβ, He I λ5876, [O I] λλ6300, 6364, [N II] λλ6548, 6583, [S II] λλ6716, 6731, [S III] λ9069, and [C I] λλ9823, 9850. We present both raw and flux-calibrated emission-line images. Arrays of 19,440 photoionization models, with extensive input abundance ranges, were matched pixel by pixel to the calibrated data in order to derive corresponding element abundance or mass-fraction distributions for helium, carbon, nitrogen, oxygen, and sulfur. These maps show distinctive structure, and they illustrate regions of gas in which various stages of nucleosynthesis have apparently occurred, including the CNO cycle, helium burning, carbon burning, and oxygen burning. It is hoped that the calibrated observations and chemical abundance distribution maps will be useful for developing a better understanding of the precursor star evolution and the supernova explosive process.
The Quark and the Jaguar: Adventures in the Simple and the Complex

This book is about how the wonderful diversity of the universe can arise out of a set of fairly simple basic laws. It is written by an expert in both the fundamental laws and the complex structures that they can produce.' Stephen Hawking's acclaim of Murray Gell-Mann's literary debut is typical of the reception the book received on first publication in 1994. From one of the twentieth century's greatest scientists comes this unique, highly personal vision of the connections between the basic laws of physics and the complexity and diversity of the natural world. THE QUARK AND THE JAGUAR - the simple and the complex - is an irresistibly engaging and rewarding introduction to the life's work of physicist, polymath and Nobel Laureate Murray Gell-Mann.
On the Fukaya categories of higher genus surfaces

Abstract We construct the Fukaya category of a closed surface equipped with an area form using only elementary (essentially combinatorial) methods. We also compute the Grothendieck group of its derived category.
Measuring Galaxy Environments with Deep Redshift Surveys

We study the applicability of several galaxy environment measures (nth-nearest neighbor distance, counts in an aperture, and Voronoi volume) within deep redshift surveys. Mock galaxy catalogs are employed to mimic representative photometric and spectroscopic surveys at high redshift (z ~ 1). We investigate the effects of survey edges, redshift precision, redshift-space distortions, and target selection on each environment measure. We find that even optimistic photometric redshift errors (σz = 0.02) smear out the line-of-sight galaxy distribution irretrievably on small scales; this significantly limits the application of photometric redshift surveys to environment studies. Edges and holes in a survey field dramatically affect the estimation of environment, with the impact of edge effects depending on the adopted environment measure. These edge effects considerably limit the usefulness of smaller survey fields (e.g., the GOODS fields) for studies of galaxy environment. In even the poorest groups and clusters, redshift-space distortions limit the effectiveness of each environment statistic; measuring density in projection (e.g., using counts in a cylindrical aperture or a projected nth-nearest neighbor distance measure) significantly improves the accuracy of measures in such overdense environments. For the DEEP2 Galaxy Redshift Survey, we conclude that among the environment estimators tested the projected nth-nearest neighbor distance measure provides the most accurate estimate of local galaxy density over a continuous and broad range of scales.
The Internet as Mass Medium

could not have missed the news stories about the Internet, many of which speculate about its effects on the ever-increasing number of people who are on line. Why, then, have communications researchers, historically concerned with exploring the effects of mass media, nearly ignored the Internet? With 25 million people estimated to be communicating on the Internet, should communication researchers now consider this network of networks’ a mass medium? Until recently, mass communications researchers have overlooked not only the Internet but the entire field of computer-mediated communication, staying instead with the traditional forms of broadcast and print media that fit much more conveniently into models for appropriate research topics and theories of mass communication. However, this paper argues that if mass communications researchers continue to largely disregard the research potential of the Internet, their theories about communication will become less useful. Not only will the discipline be left behind, it will also miss an opportunity to explore and rethink answers to some of the central questions of mass communications research, questions that go to the heart of the model of source-message-receiver with which the field has struggled. This paper proposes a conceptualization of the Internet as a mass medium, based on revised ideas of what constitutes a mass audience and a mediating technology. The computer as a new communication technology opens a space for scholars to rethink assumptions and categories, and perhaps even to find new insights into traditional communication technologies. tion as a whole, in order to place the new medium within the context of other mass media. Mass media researchers have traditionally organized themselves around a specific communications medium. The newspaper, for instance, is a more precisely defined area of interest than printing-pressmediated communiThis paper looks at the Internet, rather than computer-mediated communica
Lewis Acid-Mediated Selective Chlorinations of Silyl Enolate

A new method involving efficient, widely applicable, and highly selective α-chlorination of simple silyl enolate with Lewis acid and an α,α-dichloro-1,3-dicarbonyl controller unit was reported. Diastereoselectivity and enantioselectivity of the reaction were investigated. High reactivity and selectivity were achieved by using α,α-dichlorinated malonic ester.
Fractional order Shapiro steps in superconducting nanowires

We expose superconducting nanowires to microwave radiation in order to study phase lock-in effects in quasi-one-dimensional superconductors. For sufficiently high microwave powers a resistive branch with Shapiro steps appears in the voltage-current characteristics. At frequencies in the range of 0.9–4 GHz these steps are of integer order only. At higher frequencies steps of 1/2, 1/3, 1/4, and even 1/6 order appear. We numerically model this behavior using a multivalued current-phase relationship for nanowires.
Rhodium(II) mediated cyclizations of diazo alkynyl ketones

Abstract The rhodium(II)-catalyzed reaction of α-diazo ketones bearing tethered alkyne units represents a new and useful method for the construction of a variety of substituted cyclopentenones. The process proceeds by addition of the rhodium-stabilized carbenoid onto the acetylenic π-bond to give a vinyl carbenoid intermediate. The resulting rhodium complex undergoes a wide assortment of reactions including cyclopropanation, 1,2-hydrogen migration, CH-insertion, addition to tethered alkynes and ylide formation. The exact pathway followed is dependent on the specific metal/ligand employed and is also influenced by the nature of the solvent. Sulfonium ylide formation occurred both intra and intermolecularly when the reaction was carried out in the presence of a sulfide. In the case where an ether oxygen was present on the backbone of the vinyl carbenoid, cyclization afforded an oxonium ylide which underwent a [1,2] or [2,3]-sigmatropic shift to give a rearranged product. These cyclic metallocarbenoids were also found to interact with a neighboring carbonyl π-bond to produce carbonyl ylide dipoles that could be trapped with added dipolarophiles. The domino transformation was also performed intramolecularly by attaching an alkene directly to the carbonyl group. When 2-alkynyl-2-diazo-3-oxobutanoates were treated with a Rh(II)-catalyst, furo[3,4-c]furans were formed in excellent yield. The 1,5-electrocyclization process involved in furan formation has also been utilized to produce indeno[1,2-c]furans. Rotamer population was found to play a significant role in the cyclization of α-diazo amide systems containing tethered alkynes. In this account, an overview of our work in this area is presented.
Molecular cell biology for the refractive corneal surgeon: programmed cell death and wound healing.

BACKGROUND Variability of outcome following refractive surgical procedures is affected by corneal wound healing. Interactions between the corneal epithelium and stromal keratocytes affect both stromal remodeling and healing of the epithelium. These processes contribute to regression of initial effect, surface irregularity, and stromal scarring that occur following excimer laser photorefractive keratectomy (PRK). I review recent discoveries related to stromal-epithelial molecular interactions that provide insights into the cellular responses to refractive surgical procedures. RESULTS Injury to the corneal epithelium stimulates programmed cell death (apoptosis) of the underlying anterior stromal keratocytes. I hypothesize that apoptosis of the keratocytes occurring immediately after epithelial injury associated with refractive surgical procedures initiates the subsequent wound healing response. Activated keratocytes subsequently repopulate the anterior corneal stroma where they produce collagen and other components associated with stromal remodeling. In addition, secretion of hepatocyte growth factor and keratinocyte growth factor by keratocytes increases after corneal epithelial wounding and these growth factors stimulate proliferation and inhibit differentiation of epithelial cells, effects which could promote epithelial hyperplasia associated with regression after photorefractive keratectomy. CONCLUSION Corneal stromal-epithelial interactions help explain the different results that occur following excimer laser photorefractive keratectomy and laser in situ keratomileusis.
Dislocation Pattern Formation–Simulations of Annealing in Two Dimensions

A two-dimensional discrete dislocation dynamics code was developed and used to simulate dislocation patterning. For the present study of annealing, both glide and some climb were allowed in the simulations. In these circumstances patterning takes place even in the absence of external stresses and of dislocation sources. A triangular underlying lattice was assumed, with the three slip systems equally populated initially. Well-defined dislocation walls and cells are observed to form from random initial conditions. The structure coarsens with time, i.e. the typical size of the cells increases as annealing takes place (the smaller cells shrink and disappear from the structure). In the spirit of a bottom-up multiscale approach, it is suggested that a new simulation methodology should be developed, in which the discrete moving objects will be dislocation wall segments rather than individual dislocations.
Spatial Small Worlds: New Geographic Patterns for an Information Economy

Networks are structures that pervade many natural and manmade phenomena. Recent findings have characterized many networks as not random chaotic structures but as efficient complex formations. Current research has examined complex networks as largely a nonspatial phenomenon. Location, distance, and geography, though, are all vital aspects of a wide variety of networks. The authors examine the US portion of Internet infrastructure as a complex network and the role distance and geography play in its formation. From these findings implications are drawn on the economic, political, national security, and technological impacts of network formation and evolution in an information economy.
Ammonia Triborane: A Promising New Candidate for Amineborane-Based Chemical Hydrogen Storage

A convenient and safe method for the synthesis of ammonia triborane is reported along with studies of its hydrolytic reactions that demonstrate ammonia triborane is both soluble and stable in water but that upon the addition of acid or an appropriate transition metal catalyst it rapidly releases hydrogen. These studies indicate that ammonia triborane is a promising material for chemical hydrogen storage applications.
Neuropathologic findings after bone marrow transplantation: An autopsy study

Clinicopathologic records and neuropathologic tissues of 109 patients who underwent necropsy after treatment with bone marrow transplantation (BMT) were examined. Underlying disorders included leukemia (70), aplastic anemia (25), solid tumors (7), lymphoma (5), Hodgkin's disease (1) and Wiskott-Aldrich syndrome (1). There were 34 females and 75 males, ranging in age from 2 to 56 years. Survival after transplantation averaged 3.6 months. The most common findings were cerebrovascular lesions (29), including hematomas, hemorrhagic necrosis, and infarcts. Central nervous system infections comprised the next most common finding, including 10 fungal and four bacterial infections. A recurrence of underlying malignancy for which transplant had been performed occurred in five patients. Leukoencephalopathy of varying severity was found in eight patients, half of whom had received intrathecal chemotherapy and/or cranial radiation. Patients with systemic graft-versus-host disease had a variety of nonspecific neuropathologic findings in the nervous system; however, nearly half (44%) showed no detectable changes. Other nonspecific alterations included hypoxic/ischemic changes, vascular siderocalcinosis, and neuroaxonal spheroids (associated with hemorrhage or necrosis). These findings provide a guide as to likely causes of a neurologic syndrome in a patient who has undergone BMT, and can be compared with neuropathologic findings in other forms of immunosuppression.
Epitaxial YBa2Cu3O7 films on rolled-textured metals for high-temperature superconducting applications

Abstract The epitaxial growth of high temperature superconducting (HTS) films on rolled-textured metal represents a viable approach for long-length superconducting tapes. Epitaxial, 0.5 μm thick YBa 2 Cu 3 O 7 (YBCO) films with critical current densities, J c , greater than 1 MA cm −2 have been realized on rolled-textured (001) Ni tapes with yttria-stabilized zirconia (YSZ)/CeO 2 oxide buffer layers. This paper describes the synthesis using pulsed-laser deposition (PLD) of epitaxial oxide buffer layers on biaxially-textured metal that comprise the so-called rolling-assisted biaxially-textured substrates (RABiTS™). The properties of the buffer and YBa 2 Cu 3 O 7 films on rolled-textured Ni are discussed, with emphasis given to the crystallographic and microstructural properties that determine the superconducting properties of these multilayer structures.
Ginzburg-Landau Vortices, Coulomb Gases, and Renormalized Energies

This is a review about a series of results on vortices in the Ginzburg-Landau model of superconductivity on the one hand, and point patterns in Coulomb gases on the other hand, as well as the connections between the two topics.
Curtains and the soft architecture of the American postwar domestic environment

ABSTRACTThis article investigates the role of “soft architecture” and interior effects—including window treatments, textiles, and electric lighting—in the physcial and social construction of the postwar domestic environment in the USA. In this period the American home became an increasingly visual and visible space, defined more by the view out and the view in than by traditional conditions of domestic enclosure. Popular how-to columns and home decoration articles offered homemakers a variety of mechanisms for sustaining the appearance and psychological comfort of the modern domestic setting. Examining a range of popular decorative strategies used to mediate residential picture windows and window walls, this study challenges the deep-seated cultural and disciplinary biases associated with both the design and study of domestic architecture and interiors. Drawing upon historical documents and contemporary theorizations of the interior, this paper argues for the agency of “soft architecture” in the domestica...
Magnetoconductance of parabolically confined quasi-one-dimensional channels

Electrical conduction is studied along parabolically confined quasi-one-dimensional channels, in the framework of linear-response theory, for elastic scattering. For zero magnetic field an explicit multichannel expression for the conductance is obtained that agrees with those in the literature. A similar but new multichannel expression is obtained in the presence of a magnetic field ∥ perpendicular to the channel along the x-axis. An explicit connection is made between the characteristic time for the tunnel-scattering process and the transmission and reflection coefficients that appear in either expression. For uncoupled channels a Landauer-type expression is obtained that tends to a conductance of N parallel channels. In addition, this expression accounts explicitly for the Hall field and the confining potential, and is valid, with slight modifications, for tilted magnetic fields in the (x,z) plane.
Radion Couplings to Bulk Fields in the Randall-Sundrum Model

The radion may be the lightest new state present in the Randall-Sundrum (RS) model. We examine the couplings of the radion to the Standard Model (SM) fields in the scenario where they propagate in the bulk and expand into Kaluza-Klein towers. These couplings are then contrasted with those of the more familiar case where the SM fields are confined to the TeV-brane. We find that the couplings of the radion to both gg and γγ can be significantly different in these two cases. Implications for radion collider phenomenology are discussed.
Characteristic temperature of a tunneling-injection quantum dot laser: Effect of out-tunneling from quantum dots

Abstract A laser structure is studied, which exploits tunneling-injection of electrons and holes into quantum dots (QDs) from two separate quantum wells (QWs). An extended theoretical model is developed allowing for out-tunneling leakage of carriers from QDs into the opposite-to-injection-side QWs (electrons into the p-side QW and holes into the n-side QW). Due to out-tunneling leakage, parasitic recombination of electron-hole pairs occurs outside QDs – in the QWs and optical confinement layer. The threshold current density j th and the characteristic temperature T 0 are shown to be mainly controlled by the recombination in the QWs. Even in the presence of out-tunneling from QDs and recombination outside QDs, a tunneling-injection laser shows potential for significant improvement of temperature stability of j th – the characteristic temperature T 0 remains very high (above 300 K at room temperature) and not significantly affected by the QD size fluctuations.
Synthesis of Spiro-fused Pyrazolidoylisoxazolines

Routes to structurally unique spiro-fused pyrazolidoylisoxazolines are reported. These methods start with monosubstituted hydrazines or hydrazides and utilize the nitrile oxide 1,3-dipolar cycloaddition reaction to generate the targeted spiro-fused bis-heterocycles. Molecular shape space diversity analyses were performed on these pyrazolidoylisoxazolines showing that manipulation of the appended R groups significantly changes the molecular shape.
The total synthesis of bisucaberin

Abstract The first total synthesis of 6,17-dihydroxy-1,6,12,17-tetraazacyclodocosane-2,5,13,16-tetrone (bisucaberin) is presented. The synthetic scheme employed in this study illustrates the utility of O-benzyl-N-( tert -butoxycarbonyl)-N-(4-cyanobutyl)hydroxylamine 3 , as an intermediate in the synthesis of both bisucaberin and desferrioxamine B. The bisucaberin macrocyclic lactam precursor, a linear ω-amino acid 10 , is constructed from the intermediates 3 and O-benzyl-N-(4-cyanobutyl)hydroxylamine 4 , utilizing a series of sequential acylations and nitrile reductions. Cyclization of 10 generates the 22 membered ring, 6,17-dibenzylbisucaberin 11 . Deprotection of the hydroxamates in the last step affords the natural product, bisucaberin 1 .
Surface Magnetism Effects in Time-Distance Helioseismology

Recent observations of helioseismic holography revealed that magnetic fields that are inclined relative to the line-of-sight direction could cause systematic variations in measured acoustic phase shifts (hereafter, inclined magnetic field effect) and that the presence of surface magnetic field may shift the phases and impair the coherence of acoustic waves (known as the showerglass effect), thus complicating the interpretation of acoustic wave propagation time through the solar interior. In this paper we examine how these two observational effects affect time-distance helioseismology measurements in magnetic regions. It is confirmed that the inclined magnetic field could cause variations in time-distance measured acoustic travel times inside sunspot penumbra as well; however, inversions of the measured times for the wave propagation show that this effect only slightly shifts the location of negative sound-speed variations near the solar surface but basically does not change the inverted deeper interior structures. Further measurements using continuum intensitygrams and line-depth data from the MDI on board SOHO illustrate that the inclined magnetic field does not cause any obvious systematic travel-time variations in these observations. Regarding to the showerglass effect, we find that outgoing and ingoing travel-time perturbations through sunspots from our typical time-distance measurements are significantly smaller than those reported from helioseismic holography and also strongly depend on the propagation depth indicating deep changes. In addition, our second-skip cross-correlation experiments demonstrate that inside sunspots, the half of the double-skip travel times are very similar to the mean single-skip travel times, indicating that acoustic signals observed inside sunspots do not introduce detectable phase shifts after applying proper phase-speed filtering.
The allenic Pauson-Khand cycloaddition. Dependence in π-bond selectivity on substrate structure

Abstract Alkynyl allenes undergo intramolecular Pauson-Khand (P-K) cycloadditions to provide functionalized α-methylene and 4-alkylidene cyclopentenones in good yields. These studies have demonstrated a dependence of the π-bond selectivity of this cycloaddition on the substitution pattern of the allene.
Homotopy theory of modules over operads in symmetric spectra

We establish model category structures on algebras and modules over operads in symmetric spectra and study when a morphism of operads induces a Quillen equivalence between corresponding categories of algebras (resp. modules) over operads.
OPERATOR ALGEBRAS OF FUNCTIONS

Abstract We present some general theorems about operator algebras that are algebras of functions on sets, including theories of local algebras, residually finite-dimensional operator algebras and algebras that can be represented as the scalar multipliers of a vector-valued reproducing kernel Hilbert space. We use these to further develop a quantized function theory for various domains that extends and unifies Agler's theory of commuting contractions and the Arveson–Drury–Popescu theory of commuting row contractions. We obtain analogous factorization theorems, prove that the algebras that we obtain are dual operator algebras and show that for many domains, supremums over all commuting tuples of operators satisfying certain inequalities are obtained over all commuting tuples of matrices.
Silicon: An Essential Element For The Chick

Silicon is required for normal growth and development in the chick when a low silicon diet is fed in a trace element controlled environment. Day-old deutectomized cockerels fed a purified amino acid diet showed significantly retarded growth and development within 2 to 3 weeks. Chicks fed the same diet plus a silicon supplement showed 50 percent higher growth and normal development. Silicon meets the criteria for an essential trace element.