bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solar Tides as Revealed by Measurements of Mesosphere Temperature by the MLS Experiment on UARS
Authors: Forbes Jeffrey M. , Wu Dong 
Published: July 2006

Abstract
Temperatures between 25 and 86 km measured by the Microwave Limb Sounder (MLS) experiment on the Upper Atmosphere Research Satellite (UARS) are analyzed to delineate diurnal, semidiurnal, and terdiurnal tidal structures and stationary planetary waves. These Fourier components are determined from temperatures averaged in bins covering 5° latitude, 30° longitude and 1 h in local time. This study confirms the presence of diurnal nonmigrating tides with zonal wavenumbers s = 0, 2, −3 [s &gt; 0 (s &lt; 0) implying westward (eastward) propagation] and semidiurnal tides with s = 1 and 3, and some components of lesser importance that were previously determined from UARS wind measurements near 95 km. The seasonal–latitudinal and height structures of these components are now revealed, and utilized to aid in interpreting their behaviors and ascertaining their origins. New discoveries include the terdiurnal s = 2 and s = 4 components, and trapped nonmigrating diurnal tides with s = 0 and s = 2. The former are likely to arise from nonlinear interaction between the migrating (s = 3) terdiurnal tide and the stationary planetary wave with s = 1. The latter may reflect the presence of a longitude-dependent in situ heat source, or in situ nonlinear interaction between the migrating diurnal tide and a stationary planetary wave with s = 1. The present results provide a rich mixture of observational results to challenge both mechanistic and general circulation models of the middle atmosphere. In addition, internal consistency is established between the MLS tidal temperatures at 86 km and previously derived tidal winds at 95 km within the context of tidal theory. This result represents one step in the validation of measurements required for successful application of data-model assimilation techniques to the mesosphere and lower thermosphere.
Circulation Sensitivity to Tropopause Height
Authors: Williams G. P. 
Published: July 2006

Abstract
The possibility that the tropopause could be lower during an ice-age cooling leads to an examination of the general sensitivity of global circulations to the tropopause height by altering a constant stratospheric temperature Ts in calculations with a dry, global, multilevel, spectral, primitive equation model subject to a simple Newtonian heating function. In general, lowering the tropopause by increasing the stratospheric temperature causes the jet stream to move to lower latitudes and the eddies to become smaller. Near the standard state with Ts = 200 K, the jets relocate themselves equatorward by 2° in latitude for every 5 K increase in the stratospheric temperature. A double-jet system, with centers at 30° and 60° latitude, occurs when the equatorial tropopause drops to 500 mb (for Ts = 250 K), with the high-latitude component extending throughout the stratosphere.
The eddy momentum flux mainly traverses poleward across the standard jet at 40°, in keeping with the predominantly equatorward propagation of the planetary waves. But when the jet lies at 30° (for Ts = 225 K) the flux converges on the jet in keeping with planetary waves that propagate both equatorward and poleward. Two sets of such wave propagation occur in the double-jet system. As the troposphere becomes even shallower, the flux reverts to being primarily poleward across the jet (for Ts = 260 K) but then becomes uniquely primarily equatorward across the jet (for Ts = 275 K) before the circulation approaches extinction. Thus the existence of a predominantly poleward flux in the standard state appears to be parametrically fortuitous.
Numerical and Analytical Estimates of M2 Tidal Conversion at Steep Oceanic Ridges
Authors: Di Lorenzo Emanuele , Young William R. , Smith Stefan Llewellyn 
Published: July 2006

Abstract
Numerical calculations of the rate at which energy is converted from the external to internal tides at steep oceanic ridges are compared with estimates from analytic theories. The numerical calculations are performed using a hydrostatic primitive equation ocean model that uses a generalized s-coordinate system as the vertical coordinate. The model [Regional Ocean Modeling System (ROMS)] estimates of conversion compare well with inviscid and nondiffusive theory in the sub- and supercritical regimes and are insensitive to the strength of viscosity and diffusivity. In the supercritical regime, the nondissipative analytic solution is singular all along the internal tide beams. Because of dissipation the ROMS solutions are nonsingular, although the density gradients are strongly enhanced along the beams. The agreement between model and theory indicates that the prominent singularities in the inviscid solution do not compromise the estimates of tidal conversion and that the linearization used in deriving the analytical estimates is valid. As the model beams radiate from the generation site the density gradients are further reduced and up to 20% of the energy is lost by model dissipation (vertical viscosity and diffusion) within 200 km of the ridge. As a result of the analysis of the numerical calculations the authors also report on the sensitivity of tidal conversion to topographic misrepresentation errors. These errors are associated with inadequate resolution of the topographic features and with the smoothing required to run the ocean model. In regions of steep topographic slope (i.e., the Hawaiian Ridge) these errors, if not properly accounted for, may lead to an underestimate of the true conversion rate up to 50%.
Structure of the Baroclinic Tide Generated at Kaena Ridge, Hawaii
Authors: Nash Jonathan D. , Kunze Eric , Lee Craig M. , Sanford Thomas B. 
Published: July 2006

Abstract
Repeat transects of full-depth density and velocity are used to quantify generation and radiation of the semidiurnal internal tide from Kaena Ridge, Hawaii. A 20-km-long transect was sampled every 3 h using expendable current profilers and the absolute velocity profiler. Phase and amplitude of the baroclinic velocity, pressure, and vertical displacement were computed, as was the energy flux. Large barotropically induced isopycnal heaving and strong baroclinic energy-flux divergence are observed on the steep flanks of the ridge where upward and downward beams radiate off ridge. Directly above Kaena Ridge, strong kinetic energy density and weak net energy flux are argued to be a horizontally standing wave. The phasing of velocity and vertical displacements is consistent with this interpretation. Results compare favorably with the Merrifield and Holloway model.
Internal Tides and Turbulence along the 3000-m Isobath of the Hawaiian Ridge
Authors: Lee Craig M. , Sanford Thomas B. , Kunze Eric , Nash Jonathan D. , Merrifield Mark A. , Holloway Peter E. 
Published: July 2006

Abstract
Full-depth velocity and density profiles taken along the 3000-m isobath characterize the semidiurnal internal tide and bottom-intensified turbulence along the Hawaiian Ridge. Observations reveal baroclinic energy fluxes of 21 ± 5 kW m−1 radiating from French Frigate Shoals, 17 ± 2.5 kW m−1 from Kauai Channel west of Oahu, and 13 ± 3.5 kW m−1 from west of Nihoa Island. Weaker fluxes of 1–4 ± 2 kW m−1 radiate from the region near Necker Island and east of Nihoa Island. Observed off-ridge energy fluxes generally agree to within a factor of 2 with those produced by a tidally forced numerical model. Average turbulent diapycnal diffusivity K is (0.5–1) × 10−4 m2 s–1 above 2000 m, increasing exponentially to 20 × 10−4 m2 s–1 near the bottom. Microstructure values agree well with those inferred from a finescale internal wave-based parameterization. A linear relationship between the vertically integrated energy flux and vertically integrated turbulent dissipation rate implies that dissipative length scales for the radiating internal tide exceed 1000 km.
Tidal Mixing Events on the Deep Flanks of Kaena Ridge, Hawaii
Authors: Aucan Jerome , Merrifield Mark A. , Luther Douglas S. , Flament Pierre 
Published: July 2006

AbstractA 3-month mooring deployment (August–November 2002) was made in 2425-m depth, on the south flank of Kaena Ridge, Hawaii, to examine tidal variations within 200 m of the steeply sloping bottom. Horizontal currents and vertical displacements, inferred from temperature fluctuations, are dominated by the semidiurnal internal tide with amplitudes of ≥ 0.1 m s−1 and ∼100 m, respectively. A series of temperature sensors detected tidally driven overturns with vertical scales of ∼100 m. A Thorpe scale analysis of the overturns yields a time-averaged dissipation near the bottom of 1.2 × 10−8 W kg−1, 10–100 times that at similar depths in the ocean interior 50 km from the ridge. Dissipation events much larger than the overall mean (up to 10−6 W kg−1) occur predominantly during two phases of the semidiurnal tide: 1) at peak downslope flows when the tidal stratification is minimum (N = 5 × 10−4 s−1) and 2) at the flow reversal from downslope to upslope flow when the tidal stratification is ordinarily increasing (N = 10−3 s−1). Dissipation associated with flow reversal mixing is 2 times that of downslope flow mixing. Although the overturn events occur at these tidal phases and they exhibit a general spring–neap modulation, they are not as regular as the tidal currents. Shear instabilities, particularly due to tidal strain enhancements, appear to trigger downslope flow mixing. Convective instabilities are proposed as the cause for flow reversal mixing, owing to the oblique propagation of the internal tide down the slope. The generation of similar tidally driven mixing features on continental slopes has been attributed to oblique wave propagation in previous studies. Because the mechanical energy source for mixing is primarily due to the internal tide rather than the surface tide, the observed intermittency of overturn events is attributed to the broadbanded nature of the internal tide.
Cluster analysis for DNA methylation profiles having a detection threshold
Authors: Marjoram Paul , Chang Jing , Laird Peter W , Siegmund Kimberly D 
Published: July 2006

Abstract

Background
DNA methylation, a molecular feature used to investigate tumor heterogeneity, can be measured on many genomic regions using the MethyLight technology. Due to the combination of the underlying biology of DNA methylation and the MethyLight technology, the measurements, while being generated on a continuous scale, have a large number of 0 values. This suggests that conventional clustering methodology may not perform well on this data.

Results
We compare performance of existing methodology (such as k-means) with two novel methods that explicitly allow for the preponderance of values at 0. We also consider how the ability to successfully cluster such data depends upon the number of informative genes for which methylation is measured and the correlation structure of the methylation values for those genes. We show that when data is collected for a sufficient number of genes, our models do improve clustering performance compared to methods, such as k-means, that do not explicitly respect the supposed biological realities of the situation.

Conclusion
The performance of analysis methods depends upon how well the assumptions of those methods reflect the properties of the data being analyzed. Differing technologies will lead to data with differing properties, and should therefore be analyzed differently. Consequently, it is prudent to give thought to what the properties of the data are likely to be, and which analysis method might therefore be likely to best capture those properties.
Molecular characterization of retinal stem cells and their niches in adult zebrafish
Authors: Raymond Pamela A , Barthel Linda K , Bernardos Rebecca L , Perkowski John J 
Published: July 2006

Abstract
Background
The persistence in adult teleost fish of retinal stem cells that exhibit all of the features of true 'adult stem cells' – self-renewal, multipotency, and the capacity to respond to injury by mitotic activation with the ability to regenerate differentiated tissues – has been known for several decades. However, the specialized cellular and molecular characteristics of these adult retinal stem cells and the microenvironmental niches that support their maintenance in the differentiated retina and regulate their activity during growth and regeneration have not yet been elucidated.

Results
Our data show that the zebrafish retina has two kinds of specialized niches that sustain retinal stem cells: 1) a neuroepithelial germinal zone at the interface between neural retina and ciliary epithelium, called the ciliary marginal zone (CMZ), a continuous annulus around the retinal circumference, and 2) the microenvironment around some Müller glia in the differentiated retina. In the uninjured retina, scattered Müller glia (more frequently those in peripheral retina) are associated with clusters of proliferating retinal progenitors that are restricted to the rod photoreceptor lineage, but following injury, the Müller-associated retinal progenitors can function as multipotent retinal stem cells to regenerate other types of retinal neurons. The CMZ has several features in common with the neurogenic niches in the adult mammalian brain, including access to the apical epithelial surface and a close association with blood vessels. Müller glia in the teleost retina have a complex response to local injury that includes some features of reactive gliosis (up-regulation of glial fibrillary acidic protein, GFAP, and re-entry into the cell cycle) together with dedifferentiation and re-acquisition of phenotypic and molecular characteristics of multipotent retinal progenitors in the CMZ (diffuse distribution of N-cadherin, activation of Notch-Delta signaling, and expression of rx1, vsx2/Chx10, and pax6a) along with characteristics associated with radial glia (expression of brain lipid binding protein, BLBP). We also describe a novel specific marker for Müller glia, apoE.

Conclusion
The stem cell niches that support multi-lineage retinal progenitors in the intact, growing and regenerating teleost retina have properties characteristic of neuroepithelia and neurogenic radial glia. The regenerative capacity of the adult zebrafish retina with its ability to replace lost retinal neurons provides an opportunity to discover the molecular regulators that lead to functional repair of damaged neural tissue.
Differential activation of nerve fibers with magnetic stimulation in humans
Authors: Tuday Eric C , Olree Kenneth S , Horch Kenneth W 
Published: July 2006

Abstract

Background
Earlier observations in our lab had indicated that large, time-varying magnetic fields could elicit action potentials that travel in only one direction in at least some of the myelinated axons in peripheral nerves. The objective of this study was to collect quantitative evidence for magnetically induced unidirectional action potentials in peripheral nerves of human subjects. A magnetic coil was maneuvered to a location on the upper arm where physical effects consistent with the creation of unidirectional action potentials were observed.
Electromyographic (EMG) and somatosensory evoked potential (SEP) recordings were then made from a total of 20 subjects during stimulation with the magnetic coil.

Results
The relative amplitudes of the EMG and SEP signals changed oppositely when the current direction in the magnetic coil was reversed. This effect was consistent with current direction in the coil relative to the arm for all subjects.

Conclusion
A differential evocation of motor and sensory fibers was demonstrated and indicates that it may be possible to induce unidirectional action potentials in myelinated peripheral nerve fibers with magnetic stimulation.
Predictors of infusion reactions during infliximab treatment in patients with arthritis
Authors: Kapetanovic Meliha C , Larsson Lotta , Truedsson Lennart , Sturfelt Gunnar , Saxne Tore , Geborek Pierre 
Published: July 2006

AbstractIn the present study we evaluated the impact of baseline antinuclear antibody (ANA) status and use of methotrexate on development of infliximab-related infusion reactions in patients with rheumatoid arthritis (RA) or spondylarthropathies (SpAs), including psoriatic arthritis. All patients with RA (n = 213) or SpA (n = 76) treated with infliximab during the period 1999–2005 at the Department of Rheumatology in Lund, Sweden were included. ANAs were present in 28% and 25% of RA and SpA patients, respectively. Because of differences in baseline characteristics, we used a binary logistic regression model to calculate odds ratios (ORs), adjusting for age, sex and prednisolone dosage. Altogether 21% of patients with RA and 13% of patients with SpA developed infusion reactions (P = 0.126). The OR for development of infusion reactions in RA patients with baseline ANA positivity alone was 2.1. Infliximab without methotrexate and infliximab as monotherapy were associated with ORs of 3.1 and 3.6, respectively. Combining infliximab without methotrexate and ANA positivity yielded an OR for infusion reaction of 4.6. Lower age at disease onset and longer disease duration were associated with infusion reactions (P = 0.012 and P = 0.036, respectively), but age, sex, C-reactive protein, erythrocyte sedimentation rate, Health Assessment Questionnaire and Disease Activity Score-28 at baseline were not. No predictors of infusions reactions were identified in SpA patients. RA patients treated with infliximab without methotrexate, and who are positive at baseline for ANAs are at increased risk for developing infliximab-related infusion reactions.
Twenty-Four Hour Growth Hormone and Leptin Secretion in Active Postpubertal Adolescent Girls: Impact of Fitness, Fatness, and Age at Menarche
Authors: Kasa-Vubu J. Z. , Ye W. , Borer K. T. , Rosenthal A. , Meckmongkol T. 
Published: July 2006

Abstract
Context: GH is strongly related to body composition, physical activity, and pubertal progression. Adolescent girls decrease physical activity during puberty, whereas their weight increases. Because leptin is a good index of energy balance in active young women, we hypothesized that leptin is related to GH secretion in this population while taking into account fitness, fatness, and age at menarche.
Methods: We measured body composition and maximal oxygen consumption (VO2max) in 37 postpubertal adolescent girls aged 16–21 yr. GH was sampled every 10 min and leptin hourly for 24 h. We first analyzed 6-h time blocks by repeated measures for GH and leptin, with body mass index (BMI), percent body fat, and VO2max as covariates for the entire group and a lean subgroup. The deconvolution method was used to characterize GH pulsatility from individual time points.
Results: GH varied through the day (P &lt; 0.0001), with the highest concentrations overnight. BMI, percent body fat, and VO2max were related to GH concentrations in the entire group, whereas leptin predicted GH in the entire group as well as the lean subgroup of girls. Higher leptin was related to lower GH concentrations (P = 0.011), regardless of time. A log leptin level increase by 1 unit decreased GH by 27%. Pulsatility characteristics showed a 1-yr increase of age at menarche increasing total GH input by 20% (P = 0.0035) independently from BMI.
Conclusion: In postpubertal adolescent girls, leptin is related to GH concentration across the lean to overweight BMI spectrum. GH pulsatile secretion was greater in girls with later age at menarche.
The Growth Response to Growth Hormone (GH) Treatment in Children with Isolated GH Deficiency Is Independent of the Presence of the Exon 3-Minus Isoform of the GH Receptor
Authors: Blum Werner F. , Machinis Kalotina , Shavrikova Elena P. , Keller Alexandra , Stobbe Heike , Pfaeffle Roland W. , Amselem Serge 
Published: July 2006

Abstract
Context: A variant of the human GH receptor (GHR) lacks a 22-amino-acid sequence derived from exon 3 (d3-GHR). It was reported that pediatric patients, born small for gestational age or with idiopathic short stature who were homozygous or heterozygous for this variant responded better to GH treatment than those homozygous for the full-length allele (fl-GHR).
Objective: The objective was to study the impact of the GHR genotype on the phenotype and growth response in patients with isolated GH deficiency (IGHD) treated with GH.
Design: This was a retrospective, multinational, multicenter observational study.
Patients: Patients with IGHD (n = 107) were recruited.
Interventions: All patients received GH treatment at replacement doses. The GHR genotype (fl-GHR/fl-GHR, fl-GHR/d3-GHR, or d3-GHR/d3-GHR) was determined by PCR amplification.
Main Outcome Measures: Measures included height sd score, height velocity, height velocity sd score at baseline and 1 yr of GH treatment, and their changes.
Results: There was no statistically significant difference of the main outcome measures between patients with the d3-GHR allele (n = 48) and patients who were homozygous for the fl-GHR allele (n = 59). Moreover, the genotype group did not contribute significantly to the growth prediction in multiple linear regression models.
Conclusions: Our results indicate that the d3-GHR allele does not affect response to GH treatment or contribute to growth predictions in patients with IGHD who received replacement doses of GH aiming to restore a normal GH status. We did not confirm the previously reported data obtained in patients small for gestational age or with idiopathic short stature who received supraphysiological GH doses.
The Reduction of Sulfuric Acid by Hydrogen on Activated Carbon Impregnated with Copper Sulfate
Authors: Katagiri Akira , Watanabe Kiyoshi , Yoshizawa Shiro 
Published: July 2006

Abstract
The reduction of sulfuric acid has been studied for the purpose of the regeneration of activated carbon, which is used as an acceptor of sulfur dioxide from exhaust gas. When activated carbon impregnated with sulfuric acid was heated in a hydrogen atmosphere, sulfuric acid was reduced to sulfur dioxide by carbon in the temperature range from 200 °C to 350 °C. When copper sulfate was added, the sulfuric acid was reduced to sulfur dioxide, mainly by hydrogen, in the temperature range from 190 °C to 270 °C. At 227 °C, for example, the rate of reduction by hydrogen was nine times greater than the rate of reduction by carbon. Copper sulfate was sufficiently effective in an amount of one-fifth of the sulfuric acid in moles, indicating that copper in some form participates in the catalytic reaction.
The Role Played by Water in Spin State Variations among Nickel(II) Halide Complexes Containing (7R,14S)-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetraazacyclotetradecane
Authors: Ito Tasuku , Toriumi Koshiro , Ito Haruko 
Published: July 2006

Abstract
A complex dihydrate formed with nickel(II) bromide and the title macrocyclic ligand (memo-Me6[14]aneN4) crystallizes in triclinic space group P\bar1 and in orthorhombic space group Pcab. The crystal and molecular structures of the two crystal modifications have been determined by single crystal X-ray diffraction. In each compound, the nickel(II) is surrounded by a square-planar array of nitrogen atoms, giving low-spin complexes. In both compounds, water of crystallization and bromide ions are located above the hydrogen atoms of N–H groups and form hydrogen-bonded chelate rings of the type Ni–N–H···Br−···H–O···H–N. The N–H groups adjacent to the single methyl carbon and the geminal dimethyl carbon interact with bromide ion and water, respectively, in the P\bar1 form, whereas vice versa in the Pcab form. Water molecules in the present crystals and those in the previously reported crystal structure of [Ni(meso-Me6[14]aneN4)]Cl2·2H2O are involved in the same type of specific hydrogen-bonds. Because of the specific hydrogen-bonding effects, the presence of water prevents coordination of not only water itself but also halide ions, yielding thereby low-spin four coordinate complexes.