bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonequilibrium transitions in thermotropic phases of eicosenoic acid methyl esters
Authors: Chang S. P. , Rothfus J. A.
Published: March 2007

Methyl esters ofcis‐5‐eicosenoic (5‐EAME) andcis‐11‐eicosenoic (11‐EAME) acids from the seed oil ofLimnanthes alba (Meadowfoam) exhibit a degree of thermotropic polymorphism unobserved with shorter and longer chainlength monoenic methyl esters. 5‐EAME freezes at 264 K and melts at 266 K if cooled no lower than 215 K. 11‐EAME freezes at 239 K and melts at 255 K if cooled at no lower than 240 K. Solids cooled to lower temperatures undergo phase transformation to highermelting polymorphs (274 K, 5‐EAME; 262 K, 11‐EAME), and samples often exhibit double melting endotherms. Quantities of each high‐melting phase vary with time at temperatures below characteristic initiation temperatures. Highly temperature‐sensitive phase conversions suggest low temperature nucleation, followed by crystal growth and conversion, as reheating allows molecular motion. Once formed, both high‐melting phases melt with essentially the same melting entropy. Thermodynamic and kinetic analyses imply that differences exhibited by the isomeric esters derive from aliphatic configuration distal to the double bond.
Antioxidant activity of lipid‐soluble phenolic diterpenes from rosemary
Authors: Richheimer Steven L. , Bernart Matthew W. , King Greg A. , Kent Michael C. , Beiley David T.
Published: March 2007

A high‐performance liquid chromatography method for analyzing the phenolic diterpenes present in rosemary (Rosmarinus officinalis L.) and commercial rosemary extracts is reported. Carnosic acid was the major phenolic diterpene present in rosemary leaves, with lesser amounts of 12‐methoxycarnosic acid and carnosol. Several commercial rosemary extracts also were analyzed by this method, and in addition to these three compounds other phenolic diterpenes, such as 7‐methoxyrosmanol, 7‐methoxy‐epirosmanol, and rosmanol, were found in some samples. These latter three compounds seem to be artifacts, produced from carnosic acid by oxidation and cyclization. The major phenolic diterpenes were isolated, and their relative antioxidatn activities in soybean oil were measured by the Rancimat. The potency of carnosic acid was more than twice that of any other compound. The antioxidant activity of pure carnosic acid was compared to butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and tertiary butylhydroquinone (TBHQ) and was several times greater than BHT and BHA but less than TBHQ. Nuclear magnetic resonance data for several of the compounds that were incompletely characterized in previous literature are reported.
In vivo visualization of actin dynamics and actin interactions by BiFC
Authors: Anderie Ines , Schmid Andreas
Published: March 2007

The method of bimolecular fluorescence complementation (BiFC) enables selective visualization of protein interactions. While BiFC complex formation under in vitro conditions is considered to be essentially irreversible, there are hints that under in vivo conditions BiFC complex formation can be reversible. In the present study we used the BiFC method to visualize in vivo actin cytoskeleton dynamics. We demonstrate that in living cells formation of actin/actin BiFC complexes is reversible. Furthermore, we show heterologous binding between actin and protein kinase C delta (PKCδ). Treatment with phorbol esters caused translocation of actin/PKCδ complexes from the cytosol to the plasma membrane independent of an intact actin cytoskeleton. Our experiments demonstrate that the BiFC method might be a useful tool to investigate participation of the actin cytoskeleton in regulation of cell function.
Phyto-oestrogens and risk of prostate cancer in Scottish men
Authors: Heald C. L. , Ritchie M. R. , Bolton-Smith C. , Morton M. S. , Alexander F. E.
Published: April 2007

A population-based case–control study of diet, inherited susceptibility and prostate cancer was undertaken in the lowlands and central belt of Scotland to investigate the effect of phyto-oestrogen intake and serum concentrations on prostate cancer risk. A total of 433 cases and 483 controls aged 50–74 years were asked to complete a validated FFQ and provide a non-fasting blood sample. Multivariate logistic regression analysis found significant inverse associations with increased serum concentrations of enterolactone (adjusted OR 0·40, 95 % CI 0·22, 0·71] and with the consumption of soy foods (adjusted OR 0·52, 95 % CI 0·30, 0·91). However, no significant associations were observed for isoflavone intake or serum genistein, daidzein and equol. This study supports the hypotheses that soy foods and enterolactone metabolised from dietary lignans protect against prostate cancer in older Scottish men.
Dietary patterns, food groups and myocardial infarction: a case–control study
Authors: Lockheart Michael S. K. , Steffen Lyn M. , Rebnord Hege Møklebust , Fimreite Ragnhild Lekven , Ringstad Jetmund , Thelle Dag S. , Pedersen Jan I. , Jacobs David R.
Published: March 2007

Certain dietary patterns may be related to the risk of CVD. We hypothesised that a plant-centred dietary pattern would be associated with a reduced risk of first myocardial infarction (MI). A case–control study of Norwegian men and postmenopausal women (age 45–75 years) was performed. A FFQ was administered, generally within 3 d after incident MI (n106 cases). Controls (n105) were frequency matched on sex, age and geographic location. On the FFQ, 190 items were categorised into thirty-five food groups and ana priorihealthy diet pattern score was created. We estimated OR using logistic regression with adjustment for energy intake, family history of heart disease, marital status, current smoking, education and age. Among food groups, the risk of MI was significantly higher persdof butter and margarine (OR 1·66 (95 % CI 1·12, 2·46)), and lower persdof tomatoes (OR 0·53 (95 % CI 0·35, 0·79)), high-fat fish (OR 0·57 (95 % CI 0·38, 0·86)), wine (OR 0·58 (95 % CI 0·41, 0·83)), salad (OR 0·59 (95 % CI 0·40, 0·87)), wholegrain breakfast cereals (OR 0·64 (95 % CI 0·45, 0·90)), cruciferous vegetables (OR 0·66 (95 % CI 0·47, 0·93)) and non-hydrogenated vegetable oil (OR 0·68 (95 % CI 0·49, 0·95)). An abundance of cases were found to have a lowa priorihealthy diet pattern score. A dietary pattern emphasising nutrient-rich plant foods and high-fat fish and low intransfatty acids was associated with decreased risk of MI among Norwegians.
Insight into the functional versatility of RNA through model-making with applications to data fitting
Authors: Bevilacqua Philip C. , Cerrone-Szakal Andrea L. , Siegfried Nathan A.
Published: March 2007

The RNA World hypothesis posits that life emerged from self-replicating RNA molecules. For any single biopolymer to be the basis for life, it must both store information and perform diverse functions. It is well known that RNA can store information. Advances in recent years have revealed that RNA can exhibit remarkable functional versatility as well. In an effort to judge the functional versatility of RNA and thereby the plausibility that RNA was at one point the basis for life, a statistical chemical approach is adopted. Essential biological functions are reduced to simple molecular models in a minimalist, biopolymer-independent fashion. The models dictate requisite states, populations of states, and physical and chemical changes occurring between the states. Next, equations are derived from the models, which lead to complex phenomenological constants such as observed and functional constants that are defined in terms of familiar elementary chemical descriptors: intrinsic rate constants, microscopic ligand equilibrium constants, secondary structure stability, and ligand concentration. Using these equations, simulations of functional behavior are performed. These functional models provide practical frameworks for fitting and organizing real data on functional RNAs such as ribozymes and riboswitches. At the same time, the models allow the suitability of RNA as a basis for life to be judged. We conclude that RNA, while inferior to extant proteins in most, but not all, functional respects, may be more versatile than proteins, performing a wider range of elementary biological functions at a tolerable level. Inspection of the functional models and various RNA structures uncovers several surprising ways in which the nucleobases can conspire to afford chemical catalysis and evolvability. These models support the plausibility that RNA, or a closely related informational biopolymer, could serve as the basis for a fairly simple form of life.
Cloud fraction parameterization as a function of mean cloud water content and its variance using in‐situ observations
Authors: Gultepe I. , Isaac G. A.
Published: April 2007

The main objective of the present work is to use in‐situ data to parameterize cloud fraction (Cs) as a function of both cloud condensed water content and its variability over scales of 10 km and 100 km. In‐situ data were obtained during the Alliance Icing Research Study (AIRS) field project and represent mid‐latitude winter stratiform clouds. The main observations used in the analysis were condensed total water content (qc) and liquid water content. It is shown that Cs, defined as the length of cloudy segments divided by the clear and cloudy segments along a flight leg, can change up to 5%–25% if the averaging scale is changed from 10 km to 100 km. A new parameterization of Cs versus the ratio of qc to its variance is suggested. The sub‐grid scale variability is usually not known directly from the models and it needs to be obtained by prognostic or diagnostic equations. It is found that cloud sub‐grid variability, represented by the standard deviation (σ) of qc, increases with increasing qc for both 10 and 100 km scales, and σqc for 10 km scales is larger by about 50% as compared to 100 km scales for a given qc value. These conclusions suggest that both averaging scales and sub‐grid scale variability should be considered for cloud cover parameterizations.
A subsurface warm‐eddy off northern Baja California in July 2004
Authors: Jerónimo Gilberto , Gómez‐Valdés José
Published: March 2007

Upper‐ocean eddies are commonly observed from remote sensing, but submerged eddies are more difficult to detect. During July 2004, a 21‐day hydrographic survey in the southern region of the California Current was carried out to investigate the mesoscale variability. We observed for the first time a subsurface anticyclonic eddy off northern Baja California with the same water mass characteristics as the California Undercurrent. The core of the eddy was quasi‐circular with radii of 35 km and thickness of 250 m. The maximum swirl velocity was ∼3 cms−1. The water mass of the core of the eddy was characterized by potential temperature of 11°C, salinity of 34.5, and dissolved oxygen of 1.4 mll−1. The eddy propagated westward. The subsurface warm‐eddy could transport relatively saline water into the North Pacific subtropical gyre.
Impact‐induced convection as the main mechanism for formation of lunar mare basalts
Authors: Ghods Abdolreza , Arkani‐Hamed Jafar
Published: March 2007

Using a suite of numerical models, we show that impact‐induced convection in the Moon can explain the formation of lunar mare basalts, the depth range of their source region, the observed delay between impact basin formation and starting time of mare flows, and the long duration of the basaltic flows. The effects of an impact on the thermal evolution of the Moon and melt production in the mantle are investigated using convection calculations in an axisymmetric cylindrical coordinate system. An ascending mantle plume is allowed to melt as it crosses the depth of the solidus temperature. We consider two different models: permeable and impermeable. Five different viscosity models and three different impact basin sizes are examined. The total amount of melt produced by the permeable model with 1000 times viscosity contrast across the computation domain is comparable to the observed mare flows in Imbrium and Orientale basins. Moreover, the starting time of major melting in the mantle and its duration are also compatible with the observations. The model also allows a rigid lithosphere to develop beneath the basins that is capable of supporting the mascons largely created during the peak mare flow period. The model for South Pole Aitken basin results in a substantial amount of melting in the mantle, which does not seem to be compatible with the observations. A potassium, rare earth elements, and phosphorus (KREEP) layer with high concentration of radioactive elements incorporated directly beneath the crust has minor effects on the melt production in the mantle.
Estimating global distribution of boreal, temperate, and tropical tree plant functional types using clustering techniques
Authors: Wang Audrey , Price David T.
Published: March 2007

A simple integrated algorithm was developed to relate global climatology to distributions of tree plant functional types (PFT). Multivariate cluster analysis was performed to analyze the statistical homogeneity of the climate space occupied by individual tree PFTs. Forested regions identified from the satellite‐based GLC2000 classification were separated into tropical, temperate, and boreal sub‐PFTs for use in the Canadian Terrestrial Ecosystem Model (CTEM). Global data sets of monthly minimum temperature, growing degree days, an index of climatic moisture, and estimated PFT cover fractions were then used as variables in the cluster analysis. The statistical results for individual PFT clusters were found consistent with other global‐scale classifications of dominant vegetation. As an improvement of the quantification of the climatic limitations on PFT distributions, the results also demonstrated overlapping of PFT cluster boundaries that reflected vegetation transitions, for example, between tropical and temperate biomes. The resulting global database should provide a better basis for simulating the interaction of climate change and terrestrial ecosystem dynamics using global vegetation models.
Kazhdan-Lusztig-dual quantum group for logarithimic extensions of Virasoro minimal models
Authors: Feigin B. L. , Gainutdinov A. M. , Semikhatov A. M. , Tipunin I. Yu.
Published: March 2007

We derive and study a quantum group gp,q that is Kazhdan-Lusztig dual to the W-algebra Wp,q of the logarithmic (p,q) conformal field theory model. The algebra Wp,q is generated by two currents W+(z) and W−(z) of dimension (2p−1)(2q−1) and the energy-momentum tensor T(z). The two currents generate a vertex-operator ideal R with the property that the quotient Wp,q∕R is the vertex-operator algebra of the (p,q) Virasoro minimal model. The number (2pq) of irreducible gp,q representations is the same as the number of irreducible Wp,q representations on which R acts nontrivially. We find the center of gp,q and show that the modular group representation on it is equivalent to the modular group representation on the Wp,q characters and “pseudocharacters.” The factorization of the gp,q ribbon element leads to a factorization of the modular group representation on the center. We also find the gp,q Grothendieck ring, which is presumably the “logarithmic” fusion of the (p,q) model.
Cluster-enhanced X–O2 photochemistry (X=CH3I, C3H6, C6H12, and Xe)
Authors: Baklanov Alexey V. , Bogdanchikov Georgii A. , Vidma Konstantin V. , Chestakov Dmitri A. , Parker David H.
Published: March 2007

The effect of a local environment on the photodissociation of molecular oxygen is investigated in the van der Waals complex X–O2 (X=CH3I, C3H6, C6H12, and Xe). A single laser operating at wavelengths around 226nm is used for both photodissociation of the van der Waals complex and simultaneous detection of the O(PJ3,J=2,1,0) atom photoproduct via (2+1) resonance enhanced multiphoton ionization. The kinetic energy distribution (KED) and angular anisotropy of the product O atom recoil in this dissociation are measured using the velocity map imaging technique configured for either full (“crush”) or partial (“slice”) detection of the three-dimensional O(PJ3) atom product Newton sphere. The measured KED and angular anisotropy reveal a distinct difference in the mechanism of O atom generation from an X–O2 complex compared to a free O2 molecule. The authors identify two one-photon excitation pathways, the relative importance of which depends on IPx, the ionization potential of the X partner. One pathway, observed for all complexes independent of IPx, involves a direct transition to the perturbed covalent state X–O2(A′3Δu) with excitation localized on the O2 subunit. The predominantly perpendicular character of this channel relative to the laser polarization detection, together with data on the structure of the complex, allows us to confirm that X partner induced admixing of an X+–O2− charge transfer (CT) state is the perturbing factor resulting in the well-known enhancement of photoabsorption within the Herzberg continuum of molecular oxygen. The second excitation pathway, observed for X–O2 complexes with X=CH3I and C3H6, involves direct excitation into the (X+–O2−)3 CT state of the complex. The subsequent photodissociation of this CT state by the same laser pulse gives rise to the superoxide anion O2−, which then photodissociates, providing fast (0.69eV) O atoms with a parallel image pattern. Products from the photodissociation of singlet oxygen O2(bΣg+1) are also observed when the CH3I–O2 complex was irradiated. Potential energy surfaces (PES) for the ground and relevant excited states of the X–O2 complex have been constructed for CH3I–O2 using the results of CASSCF calculations for the ground and CT states of the complex as well as literature data on PES of the subunits. These model potential energy surfaces allowed us to interpret all of the observed O(PJ3) atom production channels.
Micromagnetic modal analysis of spin-transfer-driven ferromagnetic resonance of individual nanomagnets
Authors: Torres L. , Finocchio G. , Lopez-Diaz L. , Martinez E. , Carpentieri M. , Consolo G. , Azzerboni B.
Published: April 2007

In a recent investigation Sankey et al. [Phys. Rev. Lett. 96, 227601 (2006)] demonstrated a technique for measuring spin-transfer-driven ferromagnetic resonance in individual ellipsoidal PyCu nanomagnets as small as 30×90×5.5nm3. In the present work, these experiments are analyzed by means of full micromagnetic modeling finding quantitative agreement and enlightening the spatial distribution of the normal modes found in the experiment. The magnetic parameter set used in the computations is obtained by fitting static magnetoresistance measurements. The temperature effect is also included together with all the nonuniform contributions to the effective field as the magnetostatic coupling and the Ampere field. The polarization function of Slonczewski [J. Magn. Magn. Mater. 159, L1 (1996)] is used including its spatial and angular dependences. Experimental spin-transfer-driven ferromagnetic resonance spectra are reproduced using the same currents as in the experiment. The use of full micromagnetic modeling allows us to further investigate the spatial dependence of the modes. The dependence of the normal mode frequency on the dc and the external field together with a comparison to the normal modes induced by a microwave current is also addressed.
Hydrogen bonds in liquid water studied by photoelectron spectroscopy
Authors: Winter Bernd , Aziz Emad F. , Hergenhahn Uwe , Faubel Manfred , Hertel Ingolf V.
Published: March 2007

The authors report on photoelectron emission spectroscopy measurements of the oxygen 1s orbital of liquid water, using a liquid microjet in ultrahigh vacuum. By suitably changing the soft x-ray photon energy, within 600–1200eV, the electron probing depth can be considerably altered as to either predominantly access the surface or predominantly bulk water molecules. The absolute probing depth in liquid water was inferred from the evolution of the O1s signal and from comparison with aqueous salt solution. The presence of two distinctive components in the core-level photoelectron spectrum, with significantly different binding energies, is revealed. The dominant contribution, at a vertical binding energy of 538.1eV, was found in bulk and surface sensitive spectra. A weaker component at 536.6eV binding energy appears to be present only in bulk water. Hartree-Fock calculations of O1s binding energies in different geometric arrangements of the water network are presented to rationalize the experimental distribution of O1s electron binding energies.
Local integrals and their globally connected invariant structure in phase space giving rise to a promoting mode of chemical reaction
Authors: Teramoto Hiroshi , Takatsuka Kazuo
Published: March 2007

We develop a method to extract local integrals, that is, integrals defined locally in the linear regime of an arbitrary point in phase space. The individual integral represents a vibrational mode. We also propose an index that quantifies the extent of connection between neighboring local integrals. Those pieces that are smoothly connected over a wide range represent a global structure of phase space. With a six-atomic Lennard-Jones cluster, we show that it is possible to identify which vibrational mode in the potential basin correlates smoothly to that in the area of transition state, which is nothing but a reactive mode. As an application of the method, we attempt to enhance the structural transition by exciting the reactive mode thus found. This method works successfully as shown in numerical calculations.
Quasiclassical trajectory study of reactive and dissociative processes in H2+H2: Comparison with quantum-mechanical calculations
Authors: Carmona-Novillo Estela , Bartolomei Massimiliano , Hernández Marta I. , Campos-Martínez José
Published: March 2007

Quasiclassical trajectory calculations have been carried out for H2(v1=high)+H2(v2=low) collisions within a three degrees of freedom model where five different geometries of the colliding complex were considered. Within this approach, probabilities for different competitive processes are studied: four center reaction, collision induced dissociation, reactive dissociation, and three-body complex formation. The purpose is to compare in detail with equivalent quantum-mechanical wave packet calculations [Bartolomei et al., J. Chem. Phys 122, 064305 (2005)], especially the behavior of the probabilities near reaction thresholds. Quasiclassical calculations compare quite well with the quantum-mechanical ones for collision induced dissociation as well as for the four center reaction, although quantum effects become very important near thresholds, particularly for lower v1’s and for the four center process. Less quantitative agreement is found for reactive dissociation and three-body complex formation. It is found that most quantum effects are due to differences between quantum and classical vibrational distributions of H2(v1=high). Zero point energy violation has been found in the classical reactive-dissociative probabilities. Extension of these findings to full-dimensional treatments is examined.
Tomographic interferometry of a filtered high-current vacuum arc plasma
Authors: Warr George B. , Tarrant Richard N. , Bilek Marcela M. M. , McKenzie David R. , Harris Jeffrey H. , Howard John , Blackwell Boyd D.
Published: April 2007

Tomography of a plasma enables the distribution of electron density to be visualized. We report on the design of two tomographic interferometer systems used to measure plasma electron density distributions in a high-current pulsed cathodic vacuum arc. The method is shown to be capable of microsecond time resolution. The spatial resolution of the quasioptical interferometer operating at 2 mm wavelength is 20 mm and the spatial resolution of the waveguide-based interferometer operating at 8 mm wavelength is 50 mm. In both cases the resolution achieved depends on the launching and receiving geometries. We developed criteria for assessing the tomogram for artifacts arising from limited sampling. First results of the spatial and temporal history of plasma in a high-current vacuum arc guided by a curved magnetic filter are presented and indicate poloidal field fluctuations reminiscent of magnetohydrodynamic instabilities in pinches. The applicability of the tomographic interferometry method to optimize plasma transport through the filter is also demonstrated.
Studies on the room temperature growth of nanoanatase phase TiO2 thin films by pulsed dc magnetron with oxygen as sputter gas
Authors: Karuppasamy A. , Subrahmanyam A.
Published: March 2007

The anatase phase titanium dioxide (TiO2) thin films were deposited at room temperature by pulsed dc magnetron sputtering using pure oxygen as sputter gas. The structural, optical, electrical, and electrochromic properties of the films have been studied as a function of oxygen pressure in the chamber. The x-ray diffraction results indicate that the films grown above 4.5×10−2mbar are nanocrystalline (grain size of 28–43nm) with anatase phase. The films deposited at the chamber pressure of 7.2×10−2mbar are found to be highly crystalline with a direct optical band gap of 3.40eV, refractive index of 2.54 (at λ=400nm), and work function of 4.77eV (determined by the Kelvin probe measurements). From the optical emission spectra of the plasma and transport of ions in matter calculations, we find that the crystallization of TiO2 at room temperature is due to the impingement of electrons and ions on the growing films. Particularly, the negative oxygen ions reflected from the target by “negative ion effects” and the enhanced density of TiO, TiO+, TiO2+, and O2+ particles in the plasma are found to improve the crystallization even at a relatively low temperature. From an application point of view, the film grown at 7.2×10−2mbar was studied for its electrochromic properties by protonic intercalation. It showed good electrochromic behavior with an optical modulation of ∼45%, coloration efficiency of 14.7cm2C−1, and switching time (tc) of 50s for a 2×2cm2 device at λ=633nm.
Measurements of the effects of the intensity pickets on laser imprinting for direct-drive, adiabat-shaping designs on OMEGA
Authors: Smalyuk V. A. , Goncharov V. N. , Anderson K. S. , Betti R. , Craxton R. S. , Delettrez J. A. , Meyerhofer D. D. , Regan S. P. , Sangster T. C.
Published: March 2007

Effects of the intensity pickets on laser imprinting were investigated using laser-driven, planar plastic and foam targets on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. Intensity pickets are used in adiabat-shaping techniques designed to improve stability of inertial confinement fusion targets. The measurements were performed in planar foam targets using the decaying shock method of adiabat shaping and in planar plastic targets using the relaxation (RX) method. In foam targets, the picket reduced the target areal-density modulations by ∼6 times at shorter spatial wavelengths of 30 and 60μm, while at a longer wavelength of 120μm there was no reduction. The “imprint efficiency,” the equivalent surface amplitude produced by imprinting, was reduced by the intensity picket by a factor of ∼3 at a spatial wavelength of 60μm, while it was increased by a factor of ∼2 at a 120-μm spatial wavelength. In plastic targets, used to test the RX method, the imprint efficiency was reduced by the intensity picket by a factor of ∼2 at spatial wavelengths of 30 and 60μm, while it was about the same at a 120-μm spatial wavelength.
Optical investigations of InN nanodots capped by GaN at different temperatures
Authors: Ku C. S. , Chou W. C. , Lee M. C.
Published: March 2007

InN nanodots capped with GaN for temperatures from 600to730°C were investigated. While the dot emission intensity at 0.77eV decreased with increasing capping temperature, two extra visible emission bands appeared around 2.37eV (green band) and 2.96eV (violet band). Furthermore, x ray diffraction shows that the 71.7° and 70.2° peaks were tentatively attributed to InGaN alloy with In fractions of 14.8% and 34.2%, respectively. Moreover, the near-field measurements helped reveal the regions of different emissions. The violet-band mapping showed a spatial distribution in contrast to nanodot distribution but the green band showed a uniform distribution that apparently reflects the capping induced InGaN alloy.
Study of Al∕Nb interface by spectroscopy of reflected electrons
Authors: Afanas’ev Victor P. , Lubenchenko Alexander V. , Lukashevsky Mikhail V. , Norell Mats , Pavolotsky Alexey B.
Published: March 2007

We have studied Al∕Nb interface with help of spectroscopy of reflected electrons. Ion sputtering combined with monitoring of Auger peaks has been used to approach the interface. The developed method of quantitative interpretation of spectra allowed us to characterize the distribution of Al and Nb in the interface region with a nanometer depth resolution. The Al∕Nb interface was found to have an intermediate layer of about 10nm thickness, which is more likely due to the interface roughness, rather than diffusion smearing. We discuss the possibility to distinguish by means of spectroscopy of reflected electrons either material under analysis is a single phase or a mixture of two phases.
A new application of the Korteweg–de Vries Benjamin-Ono equation in interfacial electrohydrodynamics
Authors: Gleeson H. , Hammerton P. , Papageorgiou D. T. , Vanden-Broeck J.-M.
Published: March 2007

We consider waves on a layer of finite depth governed by the Euler equations in the presence of gravity, surface tension, and vertical electric fields. We use perturbation theory to identify canonical scalings and to derive a Korteweg–de Vries Benjamin-Ono equation arising in interfacial electrohydrodynamics. When the Bond number is equal to 1∕3, dispersion disappears and the equation reduces to the Benjamin-Ono equation. In the additional limit of vanishing electric fields, we show how to obtain a new evolution equation that contains third- and fifth-order dispersion as well as a nonlocal electric field term.
Relaxorlike dielectric dynamics in the lead-free K0.5Na0.5NbO3-SrZrO3 ceramic system
Authors: Bobnar Vid , Holc Janez , Hrovat Marko , Kosec Marija
Published: April 2007

We have detected a typical relaxor/glasslike dielectric response in the derived lead-free (1−x)K0.5Na0.5NbO3-(x)SrZrO3 ceramic system. In the compositional range 0.10≤x≤0.33, where solid solubility was observed, the system exhibits a broad dispersive dielectric maximum, a Vogel–Fulcher temperature dependence of the characteristic relaxation frequency, and a paraelectric-to-glass crossover in the temperature dependence of the dielectric nonlinearity. As the relatively high values of the dielectric constant, exceeding 5000 in the x=0.15 compound, are only weakly dependent on the frequency in the range of 20 Hz–1 MHz, and, furthermore, the history-dependent effects play only a minor role in comparison to some widely used lead-based relaxors, this environmentally friendly system seems to be very promising for a variety of applications.
Controlling line-edge roughness and reactive ion etch lag in sub-150 nm features in borophosphosilicate glass
Authors: Bhatnagar Parijat , Panda Siddhartha , Edleman Nikki L. , Allen Scott D. , Wise Richard , Mahorowala Arpan
Published: April 2007

We have developed a reactive ion etch (RIE) process in borophosphosilicate glass (BPSG) for 150 nm line-and-space features, where line-edge roughness (LER) complemented with RIE lag becomes a major issue. Effect of flow rates and carbon-to-fluorine atomic ratio of fluorohydrocarbon gases was utilized to achieve acceptable process window allowing lower radio frequency powers therefore obtaining acceptable LER and RIE lag in the high-resolution features etched into BPSG.
Isotopic labeling study of the oxygen diffusion in HfO2∕SiO2∕Si
Authors: Zhao Ming , Nakajima Kaoru , Suzuki Motofumi , Kimura Kenji , Uematsu Masashi , Torii Kazuyoshi , Kamiyama Satoshi , Nara Yasuo , Watanabe Heiji , Shiraishi Kenji , Chikyow Toyohiro , Yamada Keisaku
Published: March 2007

The characteristic oxygen diffusion in HfO2∕SiO2∕Si structure during the annealing in oxygen has been investigated by high-resolution Rutherford backscattering spectroscopy in combination with oxygen isotope substitution at 900°C in 0.1Torr O218. The observed O18 profile suggests that oxygen molecules are decomposed into atomic oxygen in the HfO2 layer and diffuse through the oxide layer via exchange mechanism. This is also supported by the observed activation energy of ∼0.6eV for the growth of the interfacial SiO2 layer.
Real-time observation of oxidation and photo-oxidation of rubrene thin films by spectroscopic ellipsometry
Authors: Kytka M. , Gerlach A. , Schreiber F. , Kováč J.
Published: March 2007

The authors follow in real time and under controlled conditions the oxidation of the organic semiconductor rubrene grown on SiO2 using spectroscopic ellipsometry. They derive the complex dielectric function ε1+iε2 for pristine and oxidized rubrene showing that the oxidation is accompanied by a significant change of the optical properties, namely, the absorption. The authors observe that photo-oxidation of rubrene is orders of magnitude faster than oxidation without illumination. By following different absorption bands (around 2.5 and 4.0eV for pristine rubrene and around 4.9eV for oxidized rubrene) they infer that the observed photo-oxidation of these films involves non-Fickian diffusion mechanisms.
Dispersion of magnetic metals on expanded graphite for the shielding of electromagnetic radiations
Authors: Huang Yuan , Xu Zheng , Shen Jianyi , Tang Tao , Huang Runsheng
Published: March 2007

The composites of nanoparticles of magnetic metals Co, Ni, and Ni–Fe dispersed on the nanolayers of expanded graphite (EG) were prepared by the impregnation of EG with ethanol solutions of metal acetates, followed by drying and reduction in H2. Such composites combined the properties of high electric conductivity of EG and magnetic conductivities of dispersed metals, and thus exhibited the high shielding effectiveness in a wide range of frequencies. Specifically, the composite containing 30%Ni and 70%EG reached the shielding effectiveness of 70–105dB at frequencies from 300kHzto1.5GHz.
Development of a precision indentation and scratching system with a tool force and displacement control module
Authors: Park Jae-jun , Kwon Kihwan , Bang Jinhyeok , Cho Nahmgyoo , Han Chang-soo , Choi Nak-sam
Published: April 2007

This article presents a tip-based micropatterning system with a precision device for measuring the machine force and the tool path. The machine force is obtained by a tool control module with a leaf spring and a capacitive displacement sensor. It is controlled to provide a force that ranges from 80 μN to 8 N. The force sensing unit, which is part of the module, is mounted on a PZT (PbZrTi) driven in-feed motion stage with a resolution of 1 nm. The work piece is set on an X-Y motion stage, and the position can be controlled with a tool path accuracy of 5 nm. Micropatterning and precision indentation experiments were performed, while the machined surfaces were examined by atomic force microscopy. From these results, the feasibility of the system for precise force-displacement control was verified for application in tip-based precision machining.
Estrogen receptor α is a putative substrate for the BRCA1 ubiquitin ligase
Authors: Eakin Catherine M. , MacCoss Michael J. , Finney Gregory L. , Klevit Rachel E.
Published: March 2007

The breast cancer suppressor protein, BRCA1, is a ubiquitin ligase expressed in a wide range of tissues. However, inheritance of a single BRCA1 mutation significantly increases a woman's lifetime chance of developing tissue-specific cancers in the breast and ovaries. Recently, studies have suggested this tissue specificity may be linked to inhibition of estrogen receptor α (ERα) transcriptional activation by BRCA1. Here, we show that ERα is a putative substrate for the BRCA1/BARD1 ubiquitin ligase, suggesting a possible mechanism for regulation of ERα activity by BRCA1. Our results show ERα is predominantly monoubiquitinated in a reaction that involves interactions with both BRCA1 and BARD1. The regions of BRCA1/BARD1 necessary for ERα ubiquitination include the RING domains and at least 241 and 170 residues of BRCA1 and BARD1, respectively. Cancer-predisposing mutations in BRCA1 are observed to abrogate ERα ubiquitination. The identification of ERα as a putative BRCA1/BARD1 ubiquitination substrate reveals a potential link between the loss of BRCA1/BARD1 ligase activity and tissue-specific carcinoma.
Evolution and genetic differentiation among relatives ofArabidopsis thaliana
Authors: Koch Marcus A. , Matschinger Michaela
Published: April 2007

Arabidopsis thalianais one of the most intensively studied plant species. More recently, information is accumulating about its closest relatives, the former genusCardaminopsis. A. thalianadiverged from these relatives, actually treated within three major lineages (Arabidopsis lyrata,Arabidopsis halleri, andArabidopsis arenosa), ≈5 mya. Significant karyotype evolution inA. thalianawith base chromosome number reduction fromx=8 tox=5 might indicate and favor effective genetic isolation from these other species, although hybrids are occurring naturally and have been also constituted under controlled conditions. We tested the evolutionary significance to separate thex=5 from thex=8 lineage using DNA sequence data from the plastome and the nuclear ribosomal DNA based on an extensive, representative worldwide sampling of nearly all taxonomic entities. We conclude that (i)A. thalianais clearly separated phylogenetically from thex=8 lineage, (ii) five major lineages outsideA. thalianacan be identified (A. lyrata,A. arenosa,A. halleri,Arabidopsis croatica, andArabidopsis pedemontana) together withArabidopsis cebennensis, and (iii) centers of genetic and morphological diversity are mostly in congruence and are located close to the Balkans in Austria and Slovakia outside glaciated and permafrost regions with few notable exceptions.
Divine Wisdom‐Urania
Authors: Byard Margaret M.
Published: April 2007

In February of 1639, Milton was invited by Lukas Holste, Pope Urban VIII's librarian, to attend a performance at the Barberini Palace in Rome of Chi soffre, speri, a pastoral comedy. The pope's nephews. Cardinals Francesco and Antonio Barberini, were hosts for the “3,500”1 who attended the event. It was an honor to be invited and an unusual opportunity for the young English scholar to hear one of the new “musical dramas” that were being given in Rome, Florence, and Venice. It was an extraordinary evening not only for the performance and its auspices but for the palace in which it was given.2
A Reading of John Milton's Horoscope
Authors: Rusche Harry
Published: April 2007

Sometime around 1650, the astrologer John Gad‐bury cast a horoscope for John Milton, but we now have only the chart without any interpretation that Gadbury might have rendered.1 With the help of the same kind of astrological texts available to Gadbury, I propose to interpret Milton's natal chart in the way that a Renaissance astrologer might.2 Fortunately, I have the great advantage of hindsight, which shall play no small part in my “prediction” of what the future holds for John Milton.
The Sestet of Milton's Sonnet VIII
Authors: Vance John A.
Published: April 2007

Editor's note: At a time when American Miltonists are helping their fellow scholars from England preserve national monuments to the memory of Milton such as the cottage at Chalfont St. Giles, perhaps it is fitting to notice a Victorian memorial, which was the occasion of Matthew Arnold's last public address: the Milton Window at St. Margaret's, Westminster, next to Westminster Abbey.
REVIEWS
Authors: Flannagan Roy , Hamilton Kim
Published: April 2007

Milton's Comus: Family Piece

The Emergence of the Seventeenth‐Century Protestant Aesthetic
Paradise Lost and the Rhetoric of Literary Forms
Authors: Flannagan Roy , Gottlieb Sidney , Flannagan Roy
Published: April 2007

The Experience of Defeat: Milton and Some Contemporaries

Milton and Scriptural Tradition
The Weather in Autumn 1634
Authors: Campbell Gordon , Flannagan Roy , DiCesare Mario A.
Published: April 2007

Ubi sunt?

Parker Update

Call For Papers

Third International Milton Symposium: Florence, 1988

1986 Summer Institute in the Early Printed Book

A Checklist of Recent Work on Milton
Seismic Rays and Ray Intensities in Inhomogeneous Anisotropic Media
Authors: Červený V.
Published: April 2007

A ray series expansion for seismic body waves propagating in inhomogeneous anisotropic media is studied. Methods for calculation of rays and amplitude coefficients of the ray series are suggested. A seismic ray is described by a system of ordinary differential equations of first order which can be solved by standard numerical techniques. Another system of ordinary differential equations can be used to compute amplitude coefficients. The method may be applied to general anisotropic media in which the elastic parameters are arbitrary continuous functions of all three co-ordinates.
Linear and non-linear appraisal using extremal models of bounded variation
Authors: Dosso S. E. , Oldenburg D. W.
Published: April 2007

Model features may be appraised by computing upper and lower bounds for the average value of the model over a specified region. The bounds are computed by constructing extremal models which maximize and minimize this average. In order to compute the most meaningful bounds, it is important that the allowed models are geophysically realistic. In this paper, the appraisal analysis of Oldenburg (1983) is extended to incorporate a bound on the total variation of the extremal models. Restricting the variation discriminates against highly oscillatory models and, as a consequence, the difference between upper and lower bounds is often considerably reduced. The original presentation of the funnel function bound curves is extended to include the variation of the model as another dimension. The interpreter may make use of any knowledge or insight regarding the variation of the model to generate realistic extremal models and meaningful bounds.

The appraisal analysis is extended to non-linear problems by altering the usual linearized equations so that a global norm of the model can be used in the objective function. The method is general, but is applied here specifically to compute bounds for localized conductivity averages of the Earth by inverting magnetotelluric measurements. The variation bound may be formulated in terms of conductivity or log conductivity. The appraisal is illustrated using synthetic data and field measurements from southeastern British Columbia, Canada.

Bounding the total variation may be viewed as constraining the flatness of the model. This suggests a new method of calculating (piecewise-constant) l  1 flattest models by minimizing the norm of the total variation. Unlike l  2 flattest models which vary in a smooth, continuous manner, the l  1 minimum-variation model is a least-structure model that resembles a layered earth with structural variations occurring at distinct depths.
Localization of glomerular ‘deposits’ in Henoch‐Schönlein nephritis
Authors: HEATON JULIET M. , TURNER D. R. , CAMERON J. S.
Published: April 2007

Twenty‐five renal biopsies from patients with Henoch‐Schönlein nephritis were examined using light microscopy, immunofluorescence, I μm plastic‐embedded sections and electron microscopy. The I μm plastic‐embedded sections and electron microscopy showed deposits in mesangial, subendothelial and subepithelial sites. Some of the latter were very large and similar to those which have been described as ‘humps’ in acute proliferative glomerulonephritis. Immunofluorescence showed the mesangial deposition of IgG, IgA and C3 with extension into a peripheral position in some cases. Fibrin was frequently found associated with crescents. The case for Henoch‐Schönlein disease being mediated, in part at least, by immune complex deposition, is presented.
Morphological aspects of the endocrine pancreas in a prednisolone‐treated infant
Authors: BARRESI G. , INFERRERA C. , GEMELLI M. , DE LUCA F.
Published: April 2007

The endocrine pancreas of a corticosteroid‐treated infant during the course of nephrotic syndrome was morphologically studied. Islet cell hyperpasia and dispersed endocrine cell aggregates betwen acinar tissue were observed. A marked numerical increase of B cells was identified by using cytochemical and immunofluorescent methods. Morphometric data support the morphological observations. The findings suggest that corticosteroid treatment induces endocrine cell replication and neogenesis.
Morpho‐functional differentiation in lobular carcinoma of the breast
Authors: EUSEBI V. , PICH A. , MACCHIORLATTI E. , BUSSOLATI G.
Published: April 2007

Lobular carcinoma of the breast has been studied using histochemical methods for mucosubstances; immunocytochemical methods for casein and actin; the ruthenium red electroncytochemical method for acid glycoproteins and an immunoelectroncytochemical method for casein. Mucosubstances and casein showed a similar cytoplasmic localization, but casein production was much more intense and also showed a more diffuse cytoplasmic localization. Occasionally casein assumed the form of target‐like ‘inclusions’ as seen characteristically with the mucosubstances. The neoplastic cells were not stained by antisera against actin. Ultrastructurally, some cells showed an intracytoplasmic lumen with microvilli and/or an irregular outline at one extremity which was covered by microvilli. An electron‐dense ‘fuzz’ and casein coated the microvilli of cells exposed respectively to ruthenium red and an anticasein serum followed by peroxidase‐anti‐peroxidase complexes. It is concluded that lobular carcinoma shows evidence of epithelial rather than myoepithelial differentiation with the emphasis on epithelial secretory cells engaged in intensive milk protein production. All 10 tumours tested for oestrogen receptors were positive in contradistinction to ductal carcinoma with a lower incidence of positivity. It appears that, in addition to distinctive histological and histochemical features, lobular carcinoma has an almost constant endocrine pattern in respect of its oestrogen receptor content.
Immunofluorescence on resin‐embedded material
Authors: SCOTTO J.
Published: April 2007

Some antigenic determinants can be preserved in tissues after plastic embedding. In the present study liver tissue was fixed with glutaraldehyde or paraformaldehyde, dehydrated with ethanol and toluene and embedded in araldite which was then polymerized at 37°C. Immunofluorescence was performed on semi‐thin sections etched with hydrogen peroxide. This procedure allows correlation with light microscopy (on the same stained semi‐thin section) and with electron microscopy (on adjacent ultra‐thin section). Good results were obtained with anti‐nuclear, anti‐mitochondrial, anti‐microsomal and anti‐α1‐antitrypsin sera.
Autofluorescent granular cells in oral mucosal hyperplasias
Authors: BROWNE R. M. , RIPPIN J. W.
Published: April 2007

Four hyperplastic lesions of the hard palate are described. They were characterized by the presence of an atrophic surface epithelium, an oedematous matrix and the presence of large numbers of autofluorescent granular cells. In addition there were numerous mast cells. Histochemical and electronmicroscopical studies suggest that the granules are composed of lipofuscin. The pathogenesis of these lesions is discussed.
Quality control in histopathology and diagnostic cytology
Authors: LANGLEY F. A.
Published: April 2007

The need for quality control in diagnostic histopathology and cytology is analysed together with a discussion of previously reported experience in this field. The philosophical and mathematical inferences of this type of exercise are debated also in relationship to personally observed experiences in respect of uterine cervical cytology and histology. The desirability of methods of monitoring of diagnostic quality and of obtaining quality improvement are emphasized and suggestions made regarding the techniques most suited to these objectives.