bluuebunny/crossref_metadata_2025 huggingface dataset:
What was the impact of the introduction of extracardiac completion for a single center performing total cavopulmonary connections?
Authors: Schreiber Christian , Kostolny Martin , Weipert Joachim , Holper Klaus , Vogt Manfred , Hager Alfred , Haas Felix , Hess John , Lange Rüdiger
Published: February 2005

Background:Creation of an extracardiac cavopulmonary connection has been proposed as a superior alternative to the lateral intracardiac tunnel for the completion of total cavopulmonary connection.Methods and results:We made a retrospective review of our experience with 125 patients undergoing a total cavopulmonary connection between June 1994 and January 2003. Our experience with the extracardiac connection for completion began in 1999. Since 1994, we have constructed an intracardiac tunnel in 50 patients, and an extracardiac connection in 75. Of the total number, 83 had undergone an earlier partial cavopulmonary connection. Additional intracardiac procedures were performed in 43 patients at time of completion, in 25 of those undergoing extracardiac completion, and in 18 of the patients having an intracardiac procedure. The mean size of the tube used for completion was 19 mm. The mean cross-clamp time for placement of the intracardiac tunnel was 77 min, with a median of 80.5 min, and a mean cardiopulmonary bypass time of 139 min, with a median of 131 min. For construction of the extracardiac connection, a mean cross-clamp time in 24 of the 75 patients was 54 min, with a median of 54 min. Mean cardiopulmonary bypass time for all the patients with an extracardiac connection was 100 min, with a median of 88 min. Reoperations were needed in 10 patients, 6 having intracardiac and 4 extracardiac procedures. Of these, 5 were early and 5 late, including one take down. None of the patients died after these interventions. Taken overall, 8 patients died, with 5 early deaths. In the multivariable analysis, cardiopulmonary bypass time of more than 120 min, atrioventricular valvar replacement, and banding of the pulmonary trunk prior to the total cavopulmonary connection, all reached statistical significance for early death, whereas only heterotaxy syndrome remained as the sole risk factor for late death. There was no significant difference in survival between the modifications used.Discussion:Whereas we could not identify any clinical superiority for the extracardiac approach in the short-term, the concept of extracardiac completion has helped to simplify the overall procedure. Longer follow-up will be required to elucidate any potential advantages.
Spontaneous closure of atrial septal defects within the oval fossa
Authors: Azhari Nawal , Shihata Mohammad S. , Al-Fatani Abdulelah
Published: February 2005

Objectives:To estimate the incidence and timing of spontaneous closure of atrial septal defects within the oval fossa, to study the modalities for diagnosis, and predict the need for therapeutic intervention.Methods:We reviewed retrospectively the medical records of patients with isolated atrial septal defects within the oval fossa, so-called “secundum defects”, diagnosed between January 1990 and February 2003. Based on the initial echocardiographic evaluation, we divided defects into small ones measuring from 3 to 5 mm, medium ones from 5 to 8 mm, and large ones greater than 8 mm.Results:We identified 121 patients, 50 (41.3%) of whom had failed to thrive, and 14 (11.6%) had congestive heart failure. At a mean of 44.9 ± 22.1 months following diagnosis, with a range from 12 to 102 months, the defects had closed spontaneously in 31 patients (25.6%). Of 22 patients having small defects, spontaneous closure occurred in 18 (82%) at a mean age of 18.9 ± 10.2 months. Of 27 patients with defects of medium size, 12 (44%) either experienced spontaneous closure, or else the defect effectively became a patent oval foramen, at a mean age of 51.2 ± 32.2 months. Only 1 (1.4%) of the 72 patients with a defect larger than 8 mm in size underwent spontaneous closure. The defects increased in size in 8 patients (6.6%). Intervention was necessary in 76 patients (63%) at a mean age of 75.5 ± 15.2 months.Conclusion:The initial size of a defect within the oval fossa at diagnosis is the best predictor of its natural history. Some defects increase in size with growth, irrespective of their initial size.
Regional and global right ventricular dysfunction in asymptomatic or minimally symptomatic patients with congenitally corrected transposition
Authors: Tulevski Igor I. , Zijta Frank M. , Smeijers Anika S. , Dodge-Khatami Ali , van der Wall Ernst E. , Mulder Barbara J. M.
Published: February 2005

Patients with congenitally corrected transposition are at risk of right ventricular dysfunction and failure. With this in mind, we examined 13 patients with congenitally corrected transposition, 7 not having undergone surgery, and 6 after physiological repair, comparing them with 6 healthy subjects matched for age and sex, using cardiac magnetic resonance imaging, at rest and during dobutamine stress, in order to determine regional and global right ventricular response to stress.

At rest, the patients had significantly decreased overall wall motion compared to their healthy peers (7.2 ± 0.5, versus 9.8 ± 0.4 mm). During infusion of dobutamine, overall wall motion increased to 12.8 ± 0.4 mm in the healthy subjects, versus 8.8 ± 1.0 mm in patients. At the regional level, significant differences in mural motion were found between patients and controls in the anterior (9.5 ± 1.1, versus 13.2 ± 0.6 mm), posterior (10.2 ± 1.6, versus 13.2 ± 0.8 mm), and septal segments (5.0 ± 0.8, versus 11.2 ± 0.6 mm).

At rest, overall mural thickening in patients was similar to that of controls, but significantly less in patients during stress. During dobutamine stress, patients showed significantly less regional wall thickening than controls, particularly in the septal (2.7 ± 0.6, versus 6.0 ± 0.4 mm, respectively) and in the anterior segments (4.2 ± 0.6, versus 7.8 ± 0.6 mm, respectively). Right ventricular ejection fraction strongly correlated with mural motion and thickening, both at rest and during stress.

Abnormal regional function in the systemic morphologically right ventricle may occur in patients with congenitally corrected transposition, which strongly correlates with right ventricular ejection fraction. Our findings support the hypothesis that, in patients with congenitally corrected transposition, ischemia of the right ventricular myocardium contributes to the development of right ventricular dysfunction.
Right ventricular function and ventricular perfusion defects in adults with congenitally corrected transposition: correlation of echocardiography and nuclear medicine
Authors: Espinola-Zavaleta Nilda , Alexanderson Erick , Attié Fause , Castellanos Luis Muñoz , Dueñas Roy , Rosas Martín , Keirns Candace
Published: February 2005

We undertook our study in order to evaluate right ventricular function and perfusion by conventional and contrast echocardiography in adults with congenitally corrected transposition who had not undergone cardiac surgery, comparing the echocardiographic findings with those obtained using equilibrium radionuclide ventriculography and gated single-photon emission computed tomography with Technetiumc-99 m sestamibi.

We discovered severe tricuspid regurgitation in 8 patients (61%). Right ventricular ejection fraction, as calculated by nuclear medicine, had a correlation of 0.67 (p = 0.059) with area fractional shortening and 0.84 (p = 0.01) with ejection fraction calculated by the method depending on descent of the tricuspid ring. All patients with severe tricuspid regurgitation also had right ventricular dysfunction. Of these 8 patients, 7 had persistent perfusion defects, while 6 also had ischemic perfusion defects.

Echo contrast had a high sensitivity, at 91%, and also specificity and positive predictive value, both at 100%, for persistent defects, and a negative predictive value of 66% compared to methods depending on nuclear medicine. The sensitivity of contrast echocardiography for detection of ischemic defects was 66%, the specificity 100%, the positive predictive value 100%, and the negative predictive value 77% compared to the methods involving nuclear medicine.

The method depending on descent of the tricuspid ring had the highest correlation with equilibrium radionuclide ventriculography in evaluation of right ventricular function in patients with congenitally corrected transposition.

We conclude that contrast echocardiography is extremely valuable when assessing right ventricular myocardial perfusion, having high sensitivity and specificity for detecting persistent defects, although sensitivity was less for detection of ischemic defects than that of gated single-photon emission computed tomography with Technetium-99 m Sestamibi.

Persistent and ischemic perfusion defects, together with chronic volume overload from tricuspid regurgitation, are the determining factors of right ventricular dysfunction.
An unusual case of aorto-left ventricular tunnel
Authors: Vida Vladimiro L. , Bottio Tomaso , Stellin Giovanni
Published: February 2005

An asymptomatic 4-year-old child was referred to our Institution with a provisional diagnosis of severe aortic valvar regurgitation in association with a ventricular septal defect. Intraoperatively, the aortic valve appeared bicuspid, and a tunnel of 7 mm diameter extending between the aorta and the left ventricle was found dividing the anterior commissure into two hemi-commissures. Repair was achieved by reconstructing the anterior commissure by direct reapproximation, and simultaneous obliteration of the aortic side of the tunnel. The aortic valvar leaflet was resuspended onto the arterial wall. This combined approach will hopefully reinforce the poorly supported aortic sinus, and may maintain aortic valvar competence over the long term. Our intraoperative diagnosis of aorto-left ventricular tunnel suggests consideration of this diagnosis when evaluating any patient with suspected aortic valvar incompetence.
Atrioventricular septal defect associated with type A postaxial polydactyly
Authors: Levin Solly E. , Vanderdonck Kathy
Published: February 2005

We report two more patients with the association of postaxial polydactyly and atrioventricular septal defects. Additional cardiac findings, not previously described, were tetralogy of Fallot in the first case, and double orifice right atrioventricular valve in the second child.
Late stage magmatic evolution of oceanic gabbros as a result of hydrous partial melting: Evidence from the Ocean Drilling Program (ODP) Leg 153 drilling at the Mid‐Atlantic Ridge
Authors: Koepke J. , Feig S. , Snow J.
Published: February 2005

Petrographic observations within oceanic gabbros drilled by Ocean Drilling Program (ODP) at Leg 153 from the Mid‐Atlantic Ridge, Kane Fracture Zone (MARK) area (23°N) in combination with experimental findings suggest that the late stage magmatic evolution of these gabbros is characterized by pervasive hydrous partial melting. Water‐saturated melting experiments on a variety of natural gabbros between 900 and 1000°C at 200 MPa produced newly formed minerals forming a characteristic paragenesis consisting of plagioclase, orthopyroxene, and pargasitic amphibole ± clinopyroxene. The An content of the new plagioclases is uniformly higher than that of the protolith. Olivine and clinopyroxene primocrysts react to form neoblastic orthopyroxene and pargasitic amphibole. These features can also be observed in the gabbros from the MARK area. Here we found zones at plagioclase grain boundaries showing a strong enrichment in An component, with An contents up to 20 to 25 mol % higher than those of the host plagioclase. Primary olivines and clinopyroxenes in contact with such zones react to orthopyroxene and pargasitic amphibole. These phases rim olivine and clinopyroxene and grow “interstitially,” typical petrographic characteristics of a late stage magmatic phase. The observed late stage microstructures in the gabbros thus appear to be the results of partial melting processes triggered by water‐rich fluids and are not crystallization products of a percolating differentiated late melt. Here we demonstrate that hydrothermal circulation within the gabbroic layer starts at much higher temperatures (900°–1000°C) than up to now believed. Water‐rich fluids propagate on grain boundaries in a ductile regime, causing hydrous partial melting on a large scale. A cracks system, a prerequisite in current models for enabling hydrothermal circulation, is not necessary. The observed process has the potential for transfer of heat and mass between the upper and lower oceanic crust. Provided that the water‐rich fluids triggering the partial melting process are seawater derived, this process may have a significant influence on the cooling of the deep oceanic crust which is in concordance with new thermal models implying that high‐temperature hydrothermal circulation is regarded to play an important role in transport of heat in the deep oceanic crust.
High‐precision Pb‐Sr‐Nd‐Hf isotopic characterization of USGS BHVO‐1 and BHVO‐2 reference materials
Authors: Weis Dominique , Kieffer Bruno , Maerschalk Claude , Pretorius Wilma , Barling Jane
Published: February 2005

The recent development of multiple‐collector inductively coupled plasma mass spectrometry (MC‐ICP‐MS) and increasing use of the technique have created the need for well‐characterized rock standards, especially for isotopic systems where no internal fractionation correction can be applied. This paper presents a careful leaching experiment on the U.S. Geological Survey (USGS) reference materials BHVO‐1 and BHVO‐2 (Hawaiian basalts) and documents the evidence for contamination of the rock powders during processing. This contamination accounts for the difference in Pb isotopic ratios of BHVO‐1 and BHVO‐2 as well as for their lack of homogeneity both in Pb isotopic compositions and in some trace element contents.
Forecast impact experiment with GPS radio occultation measurements
Authors: Healy S. B. , Jupp A. M. , Marquardt C.
Published: February 2005

Refractivity profiles from CHAMP GPS radio occultation measurements have been assimilated into the Met Office numerical weather prediction (NWP) system. A forecast impact experiment was run using 16 days of CHAMP data from May/June 2001, in addition to conventional and satellite observations which are used in operational forecasts. Although typically only 160 CHAMP profiles are assimilated daily, it is demonstrated that they reduce NWP temperature analysis and forecast mean and root mean square (RMS) differences against radiosondes in the upper troposphere and lower stratosphere. A significant impact is found in the Southern Hemisphere where 24 to 96 hour forecast 250 hPa temperature RMS differences are reduced by ∼0.1 K. No improvement in humidity forecasts is found because refractivity values below 4 km are not used in the experiment. These results are encouraging and would support the case for using CHAMP measurements in NWP if they were available in near real time.
A reanalysis of water abundances in the Martian atmosphere at high obliquity
Authors: Mischna Michael A. , Richardson Mark I.
Published: February 2005

We take a new look at expected atmospheric water vapor abundances on Mars during periods of high obliquity using the Geophysical Fluid Dynamics Laboratory Mars General Circulation Model. For the first time, the sublimation and burial of the present‐day residual polar caps beneath a sublimation lag is considered as the planet shifts from lower to high (45°) obliquity periods. Following the elimination of the polar deposits, the only sources for atmospheric water at high obliquity are the low latitude ice deposits emplaced prior to elimination of the polar source. Annual average water vapor abundances are predicted to be only ∼20–80 prμm during extended periods of high obliquity, one to two orders of magnitude less than previous estimates. This has implications for the climate history of the planet as it suggests that during extended periods of high obliquity, there is not a significant greenhouse warming effect from elevated atmospheric water vapor.
Passing through a giant molecular cloud: “Snowball” glaciations produced by interstellar dust
Authors: Pavlov Alexander A. , Toon Owen B. , Pavlov Anatoli K. , Bally John , Pollard David
Published: February 2005

In its motion through the Milky Way galaxy, the solar system encounters an average ‐density (≥330 H atoms cm−3) giant molecular cloud (GMC) approximately every 108 years, a dense (∼2 × 103 H atoms cm−3) GMC every ∼109 years and will inevitably encounter them in the future [Talbot and Newman, 1977]. However, there have been no studies linking such events with severe (snowball) glaciations in Earth history. Here we show that dramatic climate change can be caused by interstellar dust accumulating in Earth's atmosphere during the solar system's immersion into a dense (∼2 × 103 H atoms cm−3) GMC. The stratospheric dust layer from such interstellar particles could provide enough radiative forcing to trigger the runaway ice‐albedo feedback that results in global snowball glaciations. We also demonstrate that more frequent collisions with less dense GMCs could cause moderate ice ages.
Reconnection in a rotation‐dominated magnetosphere and its relation to Saturn's auroral dynamics
Authors: Cowley S. W. H. , Badman S. V. , Bunce E. J. , Clarke J. T. , Gérard J.‐C. , Grodent D. , Jackman C. M. , Milan S. E. , Yeoman T. K.
Published: February 2005

The first extended series of observations of Saturn's auroral emissions, undertaken by the Hubble Space Telescope in January 2004 in conjunction with measurements of the upstream solar wind and interplanetary magnetic field (IMF) by the Cassini spacecraft, have revealed a strong auroral response to the interplanetary medium. Following the arrival of the forward shock of a corotating interaction region compression, bright auroras were first observed to expand significantly poleward in the dawn sector such that the area of the polar cap was much reduced, following which the auroral morphology evolved into a spiral structure around the pole. We propose that these auroral effects are produced by compression‐induced reconnection of a significant fraction of the open flux present in Saturn's open tail lobes, as has also been observed to occur at Earth, followed by subcorotation of the newly closed flux tubes in the outer magnetosphere region due to the action of the ionospheric torque. We show that the combined action of reconnection and rotation naturally gives rise to spiral structures on newly opened and newly closed field lines, the latter being in the same sense as observed in the auroral images. The magnetospheric corollary of the dynamic scenario outlined here is that corotating interaction region‐induced magnetospheric compressions and tail collapses should be accompanied by hot plasma injection into the outer magnetosphere, first in the midnight and dawn sector, and second at increasing local times via noon and dusk. We discuss how this scenario leads to a strong correlation of auroral and related disturbances at Saturn with the dynamic pressure of the solar wind, rather than to a correlation with the north‐south component of the IMF as observed at Earth, even though the underlying physics is similar, related to the transport of magnetic flux to and from the tail in the Dungey cycle.
Speciation of size‐resolved individual ultrafine particles in Pittsburgh, Pennsylvania
Authors: Bein Keith J. , Zhao Yongjing , Wexler Anthony S. , Johnston Murray V.
Published: February 2005

Approximately 236,000 single particle mass spectra were collected throughout the duration of the Pittsburgh Supersite experiment using the third‐generation rapid single particle mass spectrometer (RSMS‐3). The instrument was operated semicontinuously for 306 days, sampling particles with aerodynamic diameters in the range of 30–1100 nm and collecting both positive and negative ion spectra, particle size, and time of detection for each particle measured. The entire data set has been fully processed and analyzed. Spectra have been clustered into 20 distinct particle classes on the basis of the distribution of their positive ion mass peaks. Negative ion spectra were classified independently within each positive ion class. Frequency of occurrence versus particle size, month of the year, and wind direction has also been calculated for the full data set, as well as within each class. Results indicate a rich array of multicomponent ultrafine particles composed primarily of carbon and ammonium nitrate. Approximately 54% of all the particles measured fell into the carbonaceous ammonium nitrate (CAN) class. These particles were observed in all size bins and from most wind directions for the entirety of this study. Ubiquitous sources throughout the area, including vehicular emissions and secondary organic aerosol formation, are considered to be responsible for a larger fraction of these particles. In terms of particle number, metal containing aerosol dominated the remainder of the particle classes identified. These particles were rich in K+, Na+, Fe+, and Pb+ and to a lesser extent, Ga+ and Zn+. They tended to be smaller in size and were highly correlated with specific wind directions, facilitating the isolation of specific sources.
Coupled patterns of spatiotemporal variability in Northern Hemisphere sea level pressure and conterminous U.S. drought
Authors: Zhang Zhihua , Mann Michael E.
Published: February 2005

We apply the multitaper frequency domain–singular value decomposition signal detection method to the investigation of coherent patterns of variation in seasonal Northern Hemisphere sea level pressure and conterminous U.S. summer drought during the period 1895–1995. The analysis identifies statistically significant patterns of spatiotemporal variability on interannual and bidecadal timescales indicative of both cold‐season and warm‐season atmospheric influences on North American drought patterns. The most robust signal found appears to be associated with the influences of the El Niño–Southern Oscillation (ENSO) on North American summer drought. Evidence is also found to support the existence of a roughly bidecadal drought signal tied to warm‐season atmospheric circulation changes. The “Dust Bowl” conditions of the 1930s appear to result from a combination of these bidecadal influences on drought conditions that coincide with a decrease in the amplitude of interannual ENSO‐related variability during the 1930s.
Dust and pollution: A recipe for enhanced ocean fertilization?
Authors: Meskhidze N. , Chameides W. L. , Nenes A.
Published: February 2005

For Fe contained in aeolian dust to act as a micronutrient for oceanic phytoplankton, some fraction of it must first be transformed (mobilized) into a form soluble in ocean water. Fe solubilization in deliquesced mineral dust aerosols emanating from East Asia during the springtime outflow conditions is investigated here with a Lagrangian box model of the gas and aqueous‐phase chemistry. The model simulates the scavenging of soluble and reactive gaseous species by mineral dust aerosols, chemical reactions of these species and mineral dust ions in deliquesced solution, and dissolution of Fe‐III oxides that occurs as a result of the acid mobilization. The calculations indicate that mineral calcite (CaCO3) strongly buffers deliquesced dust aerosols with a pH that remains close to 8 until the amount of acid added to the aerosol solution exceeds CaCO3 alkalinity. SO2 pollutant emissions are a potential source of acidity to advecting dust from East Asia. The model is used to simulate the chemical evolution of dust plumes formed from two contrasting documented Gobi‐desert storms that advected dust to Fe‐limited regions of the North Pacific Ocean (NPO). These calculations indicate that only plumes with relatively high initial SO2‐to‐dust ratios are capable of delivering significant amounts of bioavailable Fe to the NPO. The estimated change in phytoplankton population inferred from the model‐calculated inputs of bioavailable Fe for these two episodes is consistent with the satellite‐measured chlorophyll a concentrations in the NPO. Model simulations indicate that (1) large dust advection episodes, that can export vast amounts of mineral dust to the open ocean, should have insignificant dissolved iron fraction (DIF) as the amount of SO2 required to acidify such dust plumes is about an order of magnitude higher than what can typically be entrained in the plume during its advection; (2) smaller dust plumes will generally have higher DIFs because they require lower amounts of SO2 and, even if such small plumes may not cause algae blooms, they could still be important sources of dissolved Fe to the NPO. The calculations suggest that future changes in SO2‐pollutant emissions from East Asia, either up or down, may affect the productivity of the NPO.
CO2 dynamics in the Amargosa Desert: Fluxes and isotopic speciation in a deep unsaturated zone
Authors: Walvoord Michelle A. , Striegl Robert G. , Prudic David E. , Stonestrom David A.
Published: February 2005

Natural unsaturated‐zone gas profiles at the U.S. Geological Survey's Amargosa Desert Research Site, near Beatty, Nevada, reveal the presence of two physically and isotopically distinct CO2 sources, one shallow and one deep. The shallow source derives from seasonally variable autotrophic and heterotrophic respiration in the root zone. Scanning electron micrograph results indicate that at least part of the deep CO2 source is associated with calcite precipitation at the 110‐m‐deep water table. We use a geochemical gas‐diffusion model to explore processes of CO2 production and behavior in the unsaturated zone. The individual isotopic species 12CO2, 13CO2, and 14CO2 are treated as separate chemical components that diffuse and react independently. Steady state model solutions, constrained by the measured δ13C (in CO2), and δ14C (in CO2) profiles, indicate that the shallow CO2 source from root and microbial respiration composes ∼97% of the annual average total CO2 production at this arid site. Despite the small contribution from deep CO2 production amounting to ∼0.1 mol m−2 yr−1, upward diffusion from depth strongly influences the distribution of CO2 and carbon isotopes in the deep unsaturated zone. In addition to diffusion from deep CO2 production, 14C exchange with a sorbed CO2 phase is indicated by the modeled δ14C profiles, confirming previous work. The new model of carbon‐isotopic profiles provides a quantitative approach for evaluating fluxes of carbon under natural conditions in deep unsaturated zones.
Constructing and Reconstructing the Reorderable Matrix
Authors: Siirtola Harri , Mäkinen Erkki
Published: February 2005

We consider the backgrounds, applications, implementations, and user interfaces of the reorderable matrix originally introduced by Jacques Bertin. As a new tool for handling the matrix, we propose a new kind of interface for interactive cluster analysis. As the main tool to order the rows and columns, we use the well-known barycenter heuristic. Two user tests are performed to verify the usefulness of the automatic tools.
Theoretical Analysis on 3dnl J=1e–5e Autoionizing Levels in Ca
Authors: Ma Dongxia , Zheng Nengwu , Fan Jing
Published: February 2005

Previous studies on the even parity 3dnl J=1–5 autoionizing levels of calcium have been critically evaluated. These levels have been studied within the framework of the weakest bound electron potential model theory. 30 3dnl series are treated and the results are listed here. In these calculations, the jj coupling scheme is used. It is remarkable that the perturbation approach that has been emphasized in our calculations so as to adequately consider the correlation between the two excited electrons is more important than in the case of singly excited states. Compared with the experimental results and the values from other theoretical methods, the present results are in concurrence with the experimental data, and showed comparative accuracy with other methods. Some levels, which have not been reported previously, are predicted here.
Transition Probabilities for Hydrogen-Like Atoms
Authors: Jitrik Oliverio , Bunge Carlos F.
Published: February 2005

E1, M1, E2, M2, E3, and M3 transition probabilities for hydrogen-like atoms are calculated with point-nucleus Dirac eigenfunctions for Z=1–118 and up to large quantum numbers l=25 and n=26, increasing existing data more than a thousandfold. A critical evaluation of the accuracy shows a higher reliability with respect to previous works. Tables for hydrogen containing a subset of the results are given explicitly, listing the states involved in each transition, wavelength, term energies, statistical weights, transition probabilities, oscillator strengths, and line strengths. The complete results, including 1 863 574 distinct transition probabilities, lifetimes, and branching fractions are available at http://www.fisica.unam.mx/research/tables/spectra/1el
Wavelengths, Energy Level Classifications, and Energy Levels for the Spectrum of Neutral Neon
Authors: Saloman E. B. , Sansonetti Craig J.
Published: February 2005

We have prepared a comprehensive critically evaluated compilation of the most accurate wavelength measurements for classified lines of neutral neon (Ne I) in its natural isotopic abundance. Data from 19 sources spanning the region 256 Å to 54 931 Å are included. Based on this line list we have derived optimized values for the energy levels of neutral neon. Tabular data for 1595 classified lines and 374 energy levels are provided. In addition to the observed wavelengths, we present revised wavelengths calculated from the optimized energy levels for all lines that have been previously recommended for use as secondary wavelength standards.
Recursive calculation of effective potential and variational resummation
Authors: Brandt Sebastian F. , Kleinert Hagen , Pelster Axel
Published: February 2005

We set up a method for a recursive calculation of the effective potential which is applied to a cubic potential with imaginary coupling. The result is resummed using variational perturbation theory, yielding an exponentially fast convergence.
A classification of generalized quantum statistics associated with classical Lie algebras
Authors: Stoilova N. I. , Van der Jeugt J.
Published: February 2005

Generalized quantum statistics such as para-Fermi statistics is characterized by certain triple relations which, in the case of para-Fermi statistics, are related to the orthogonal Lie algebra Bn=so(2n+1). In this paper, we give a quite general mathematical definition of “a generalized quantum statistics associated to a classical Lie algebra G.” This definition is closely related to a certain Z-grading of G. The generalized quantum statistics is then determined by a set of root vectors (the creation and annihilation operators of the statistics) and the set of algebraic relations for these operators. Then we give a complete classification of all generalized quantum statistics associated to the classical Lie algebras An, Bn, Cn, and Dn. In the classification, several new classes of generalized quantum statistics are described.
Modeling wave propagation in realistic heart geometries using the phase-field method
Authors: Fenton Flavio H. , Cherry Elizabeth M. , Karma Alain , Rappel Wouter-Jan
Published: February 2005

We present a novel algorithm for modeling electrical wave propagation in anatomical models of the heart. The algorithm uses a phase-field approach that represents the boundaries between the heart muscle and the surrounding medium as a spatially diffuse interface of finite thickness. The chief advantage of this method is to automatically handle the boundary conditions of the voltage in complex geometries without the need to track the location of these boundaries explicitly. The algorithm is shown to converge accurately in nontrivial test geometries with no-flux (zero normal current) boundary conditions as the width of the diffuse interface becomes small compared to the width of the cardiac action potential wavefront. Moreover, the method is illustrated for anatomically realistic models of isolated rabbit and canine ventricles as well as human atria.
Axial and temporal gradients in Mo wire array Z pinches
Authors: LePell P. D. , Hansen S. B. , Shlyaptseva A. S. , Coverdale C. , Deeney C. , Apruzese J. P. , Fournier K. B. , Safronova U. I.
Published: February 2005

Three nested molybdenum wire arrays with initial outer diameters of 45, 50, and 55 mm were imploded by the ∼20MA, 90 ns rise-time current pulse of Sandia’s Z accelerator. The implosions generated Mo plasmas with ≈10% of the array’s initial mass reaching Ne-like and nearby ionization stages. These ions emitted 2–4 keV L-shell x rays with radiative powers approaching 10 TW. Mo L-shell spectra with axial and temporal resolution were captured and have been analyzed using a collisional-radiative model. The measured spectra indicate significant axial variation in the electron density, which increases from a few times 1020cm−3 at the cathode up to ∼3×1021cm−3 near the middle of the 20 mm plasma column (8 mm from the anode). Time-resolved spectra indicate that the peak electron density is reached before the peak of the L-shell emission and decreases with time, while the electron temperature remains within 10% of 1.7 keV over the 20–30 ns L-shell radiation pulse. Finally, while the total yield, peak total power, and peak L-shell power all tended to decrease with increasing initial wire array diameters, the L-shell yield and the average plasma conditions varied little with the initial wire array diameter.
The McCormack model for gas mixtures: Plane Couette flow
Authors: Garcia R. D. M. , Siewert C. E.
Published: February 2005

An analytical version of the discrete-ordinates method is used to establish a concise and particularly accurate solution to the problem of plane Couette flow for a binary gas mixture described by the McCormack kinetic model. The solution yields, for the general (specular-diffuse) case of Maxwell boundary conditions for each of the two species, the velocity, heat-flow, and shear-stress profiles for both types of particles, as well as the particle-flow and heat-flow rates associated with each of the two species of gas particles. Highly accurate numerical results are reported for the case of a helium–argon mixture confined between molybdenum and tantalum plates. The algorithm is considered especially easy to use, and the developed (FORTRAN) code requires typically less than a second on a 2.2GHz Pentium 4 machine to compute all quantities of interest with at least five figures of accuracy.
Brownian pants and Deligne cohomology
Authors: Léandre Rémi
Published: February 2005

We define stochastic pants, and the stochastic parallel transport over them for the Felder–Gawedzki–Kupiainen line bundle over the loop space. It is related to the construction of stochastic integrals, where we cannot use martingale theory in order to define them. We get a stochastic fusion of the two line bundles when the two loops meet.
Distributed forcing of flow over a circular cylinder
Authors: Kim Jinsung , Choi Haecheon
Published: February 2005

In the present study, we apply a distributed (i.e., spatially varying) forcing to flow over a circular cylinder for drag reduction. The distributed forcing is realized by a blowing and suction from the slots located at upper and lower surfaces of the cylinder. The forcing profile from each slot is sinusoidal in the spanwise direction but is steady in time. We consider two different phase differences between the upper and lower blowing/suction profiles: zero (in-phase forcing) and π (out-of-phase forcing). The Reynolds numbers considered are from 40 to 3900 covering various regimes of flow over a circular cylinder. For all the Reynolds numbers larger than 47, the present in-phase distributed forcing attenuates or annihilates the Kármán vortex shedding and thus significantly reduces the mean drag and the drag and lift fluctuations. The optimal wavelength and amplitude of the in-phase forcing for maximum drag reduction are also obtained for the Reynolds number of 100. It is shown that the in-phase forcing produces the phase mismatch along the spanwise direction in the vortex shedding, weakens the strength of vortical structures in the wake, and thus reduces the drag. Unlike the in-phase forcing, the out-of-phase distributed forcing does not reduce the drag at low Reynolds numbers, but it reduces the mean drag and the drag and lift fluctuations at a high Reynolds number of 3900 by affecting the evolution of the separating shear layer, although the amount of drag reduction is smaller than that by the in-phase forcing.
On the jets, kinks, and spheromaks formed by a planar magnetized coaxial gun
Authors: Hsu S. C. , Bellan P. M.
Published: February 2005

Measurements of the various plasma configurations produced by a planar magnetized coaxial gun provide insight into the magnetic topology evolution resulting from magnetic helicity injection. Important features of the experiments are a very simple coaxial gun design so that all observed geometrical complexity is due to the intrinsic physical dynamics rather than the source shape and use of a fast multiple-frame digital camera which provides direct imaging of topologically complex shapes and dynamics. Three key experimental findings were obtained: (1) formation of an axial collimated jet [Hsu and Bellan, Mon. Not. R. Astron. Soc. 334, 257 (2002)] that is consistent with a magnetohydrodynamic description of astrophysical jets, (2) identification of the kink instability when this jet satisfies the Kruskal–Shafranov limit, and (3) the nonlinear properties of the kink instability providing a conversion of toroidal to poloidal flux as required for spheromak formation by a coaxial magnetized source [Hsu and Bellan, Phys. Rev. Lett. 90, 215002 (2003)]. An interpretation is proposed for how the n=1 central column instability provides flux amplification during spheromak formation and sustainment, and it is shown that jet collimation can occur within one rotation of the background poloidal field.
Theoretical interpretation of frequency sweeping observations in the Mega-Amp Spherical Tokamak
Authors: Vann R. G. L. , Dendy R. O. , Gryaznevich M. P.
Published: February 2005

Frequency sweeping (chirping) of high frequency magnetohydrodynamic modes is widely observed in tokamak plasmas. In this paper observations of chirping in neutral-beam-heated plasmas in the Mega-Amp Spherical Tokamak (MAST) [A. Sykes, R. J. Akers, L. C. Appel et al., Nucl. Fusion 41, 1423 (2001)] are considered, and it is shown that these may be interpreted using the Berk–Breizman augmentation of the Vlasov–Maxwell equations. This model includes an energetic particle source: it leads not only to a single chirp but also to a series of bursting events. This repetitious behavior is characteristic of the chirping seen in experiments such as MAST. The similarity between features in velocity space and features in frequency space reinforces the theory that hole-clump pair formation is responsible for the observed frequency sweeping.
Long spin relaxation in self-assembled InAlAs quantum dots observed by heterodyne four-wave mixing
Authors: Watanuki T. , Adachi S. , Sasakura H. , Muto S.
Published: February 2005

Exciton spin relaxation in self-assembled InAlAs quantum dots was investigated by three-pulse four-wave mixing under resonant conditions. The concept of the spin grating holds well for quantum dots and the measurements combined with optical heterodyne detection at 10K demonstrates that the exciton spin relaxation lasts up to a few nanoseconds and the time constant is ∼5 times larger than the exciton recombination time on average.
Atomic dynamics in molecular dynamics simulations of glassy CuTi thin films
Authors: Vauth Sebastian , Mayr S. G.
Published: February 2005

We present results on atomic dynamics in metallic glass thin films below the glass transition temperature using molecular dynamics simulations. Thin CuTi films of different compositions are prepared by quenching the liquid to an amorphous state. The atomic dynamics on the amorphous surface and inside the bulk of the samples are quantitatively compared by calculating diffusion constants and jump length distributions. Here, we focus on the collective or single particle character of the diffusion mechanism in dependence of the atom type. In addition, single atom exemplifications are analyzed for the different kinds of atomic dynamics. We find that Cu surface atoms diffuse with a single atom jump dynamics, whereas inside the bulk collective behavior dominates for both species.
Perylene monolayer on the Ru(0001) surface
Authors: Lu B. , Zhang H. J. , Tao Y. S. , Huang H. , Li H. Y. , Bao S. N. , He P. , Chen Q.
Published: February 2005

The growth of epitaxial monolayer of perylene on Ru(0001) was investigated by means of scanning tunneling microscopy (STM). The STM images showed a coexistence of the ordered phase with a 12×12 superstructure and the disordered phase in a monolayer of perylene on Ru(0001). In the disordered region, the perylene molecules are randomly distributed, and orientated uniformly with their long axis in the [1000] direction. For the ordered phase, a model of the Ru(0001)-(12×12)-8 perylene superstructure was proposed. The results indicate that the growth behavior of perylene on Ru(0001) is mainly controlled by laterally repulsive molecule-molecule interaction.
The influence of coral reefs on atmospheric dimethylsulphide over the Great Barrier Reef, Coral Sea, Gulf of Papua and Solomon and Bismarck Seas
Authors: Jones Graham B. , Trevena Anne J.
Published: February 2005

Marked regional differences in dissolved dimethylsulphide (DMS), atmospheric DMS and DMS flux were recorded during July 1997 through the northern Great Barrier Reef, Coral Sea, Gulf of Papua, Solomon and Bismarck Seas. Highest concentrations of dissolved DMS occurred in the Coral Sea, Gulf of Papua and Bismarck Sea, with lower concentrations in the Great Barrier Reef and Solomon Sea. Elevated levels of atmospheric DMS often occurred in south-easterly to southerly trade winds sampled in the region 18°32′–8°12′S to 145°–151°E, where the highest biomass of coral reefs occurred. Atmospheric DMS often increased in the day after low tides and was positively correlated with tidal height in the northern Great Barrier Reef (r = 0.91, P < 0.05). For tides less than 1.6 m, atmospheric DMS increased on the rising tide for the northern GBR and NW Coral Sea (r = 0.66; P < 0.05) and for the whole voyage (r = 0.25; P < 0.05). As coral reefs have been identified as significant sources of DMS, it is suggested that the daytime increase in atmospheric DMS over much of the study area was mainly a result of high winds and extremely low tides in July, which exposed the reefs during the day.
Consolidating critical binding determinants by noncyclic rearrangement of protein secondary structure
Authors: Tabtiang Ramon K. , Cezairliyan Brent O. , Grant Robert A. , Cochrane Jesse C. , Sauer Robert T.
Published: February 2005

We designed a single-chain variant of the Arc repressor homodimer in which the β strands that contact operator DNA are connected by a hairpin turn and the α helices that form the tetrahelical scaffold of the dimer are attached by a short linker. The designed protein represents a noncyclic permutation of secondary structural elements in another single-chain Arc molecule (Arc-L1-Arc), in which the two subunits are fused by a single linker. The permuted protein binds operator DNA with nanomolar affinity, refolds on the sub-millisecond time scale, and is as stable as Arc-L1-Arc. The crystal structure of the permuted protein reveals an essentially wild-type fold, demonstrating that crucial folding information is not encoded in the wild-type order of secondary structure. Noncyclic rearrangement of secondary structure may allow grouping of critical active-site residues in other proteins and could be a useful tool for protein design and minimization.
Circadian sensitivity to the chemotherapeutic agent cyclophosphamide depends on the functional status of the CLOCK/BMAL1 transactivation complex
Authors: Gorbacheva Victoria Y. , Kondratov Roman V. , Zhang Renliang , Cherukuri Srujana , Gudkov Andrei V. , Takahashi Joseph S. , Antoch Marina P.
Published: February 2005

The circadian clock controls many aspects of mammalian physiology, including responses to cancer therapy. We find that wild-type and circadian mutant mice demonstrate striking differences in their response to the anticancer drug cyclophosphamide (CY). While the sensitivity of wild-type mice varies greatly, depending on the time of drug administration,Clockmutant andBmal1knockout mice are highly sensitive to treatment at all times tested. On the contrary, mice with loss-of-function mutations inCryptochrome(Cry1-/-Cry2-/-double knockouts) were more resistant to CY compared with their wild-type littermates. Thus, both time-of-day and allelic-dependent variations in response to chemotherapy correlate with the functional status of the circadian CLOCK/BMAL1 transactivation complex. Pharmacokinetic analysis of plasma concentration of different CY metabolites shows that, in contrast to the traditional view, circadian variations in drug sensitivity cannot be attributed to the changes in the rates of CY metabolic activation and/or detoxification. At the same time, mice of different circadian genotypes demonstrate significant differences in B cell responses to toxic CY metabolites: B cell survival/recovery rate was directly correlated with thein vivodrug sensitivity. Based on these results, we propose that the CLOCK/BMAL1 transcriptional complex affects the lethality of chemotherapeutic agents by modulating the survival of the target cells necessary for the viability of the organism.