bluuebunny/crossref_metadata_2025 huggingface dataset:
Transmission Electron Microscopy Study of Uranium Thorium Zirconium Hydride Fuels
Authors: Terrani KA
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Single Particle Electron Cryomicroscopy of Bacteriophage P22 Portal Protein Complexes
Authors: Zheng H , Wisedchaisri G , Gonen T
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Relative Contrast in Ion and Electron Induced Secondary Electron Images
Authors: Giannuzzi LA , Utlaut M , Scheinfein M
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
AFM and cryoEM studies of the giant mimivirus
Authors: Xiao C , Kuznetsov YG , Sun S , Hu B , Criswell MJ , Bator-Kelly CM , Hafenstein S , Chipman PR , Suzan-Monti M , Raoult D , McPherson A , Rossmann MG
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
ESEM, STEM-in-ESEM and 200 kV STEM Imaging of Soft Matter and Liquid-State Specimens
Authors: Jonge N De , Stokes DJ
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
A Tubular Scaffold that Modulates Differentiation of Rat Bone Marrow Stem Cells
Authors: Potts J , Yost M , Kaur G , Wang Q , Valarmathi T
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Problem Solving in Electron-probe Microanalysis: Application of Software Tools
Authors: Carpenter PK
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
EPMA Standards: The Good, the Bad, and the Ugly
Authors: Carpenter PK
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Trace-element Analyses in Lunar Meteorite Sayh al Uhaymir 169
Authors: Zeigler RA , Carpenter PK , Jolliff BL , Korotev RL
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Electron-Probe Microanalysis (EPMA): An Overview for Beginners and a Status Report for Experts
Authors: Carpenter PK
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Microfluidic Mixing System for Time Resolved Cryo-Electron Microscopy
Authors: Lu Z , McMahon J , Mohamed H , Barnard D , Shaikh TR , Wagenknecht T , Lu T-M
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Community Development in Bacterial Biofilms of the Oral Cavity
Authors: Jr RJ Palmer , Chalmers NI , Rickard AH , Kolenbrander PE
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
The Plant Extracellular Matrix
Authors: McCann MC , Penning B , Olek A , Carpita NC
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Laser Ablation ICP-MS in Geochemistry and Biogeochemistry: A Progress Report
Authors: Ridley WI , Koenig AE , Pribil MJ
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Microanalysis of Plutonium
Authors: Matthews M
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Off-Axis Electron Holography of Magnetic Fields in Biological Materials
Authors: Dunin-Borkowski RE , Kasama T , Pósfai M , Chong RKK , Simpson ET , Dobson J , Collingwood JF
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Electron Irradiation Effects in Carbon Nanostructures: Surface Reconstruction, Extreme Compression and Nanotube Growth
Authors: Terrones M
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Combined x(3) Microscopy of the Peripheral Nervous Tissue
Authors: Pfeffer CP , Vogel M , Olsen BR , Ganikhanov F
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Multivariate Analysis of XPS Data for Enhanced Chemical Information
Authors: Fulghum JE , Artyushkova K
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Statistical and Systematic Errors in EFTEM Spectral Imaging
Authors: Anderson IM , Herzing A
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
3D Imaging of Diatoms with Ion Abrasion Scanning Electron Microscopy
Authors: Hildebrand M , Kim S , Shi D , Subramaniam S
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Discovery of 250 Ma Cellulose Fibers in a Deep Permian Halite Layer Poses Unique Challenges in TEM Imaging and Analysis
Authors: Griffith J , Willcox S , Powers DW , Nelson R , Baxter BK
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Dynamic Experiments in Light Microscopy
Authors: Rothe DR , Samson R , Czerwinski E
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Growth of Inclusions in Uranium-Niobium Alloy
Authors: Brierley M
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
High-Throughput Multiphoton Tissue Cytometry
Authors: So PTC
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Recent Applications Development with the Helium Ion Microscope
Authors: Scipioni L
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Strain and its Contrast mechanisms in crystalline materials imaged with FE-SEM
Authors: Jaksch H
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Pushing back the frontiers of CRYO in 120 kV TEMs
Authors: Hiller SA , Dietl C , Seybold V , Thaler M , Benner G
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Stereological Characterization of the Geometry of Three Dimensional Microstructures
Authors: DeHoff RT
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Development of Monovalent Fluorescent Probes for Single Particle Tracking of ErbB Receptors
Authors: Low-Nam ST , Wilson BS , Lidke DS
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Production and Measurement of Sputtered Iridium
Authors: Savage P , Mansfield J
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Hyperspectral X-ray Analysis of Submicrometer-scale Heterogeneities in a Venerable Compositional Standard Provided by Nature: Kakanui Hornblende
Authors: Vicenzi EP , Rose T
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Electron Gun Design for Pulsed TEM Operation
Authors: Ziegler A
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Remote Microscopy for Training Groups of Student Users
Authors: Mansfield JF
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Same-Day Diagnostic Electron Microscopy of Infected Cell Cultures by a Modified Protocol for Conventional and Microwave Processing
Authors: Metcalfe MG , Rollin D , Humphrey CD
Published: August 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
New molecular targets in angiogenic vessels of glioblastoma tumours
Authors: Anderson Joshua C. , McFarland Braden C. , Gladson Candece L.
Published: August 2008

Antiangiogenesis approaches have the potential to be particularly effective in the treatment of glioblastoma tumours. These tumours exhibit extremely high levels of neovascularisation, which may contribute to their extremely aggressive behaviour, not only by providing oxygenation and nutrition, but also by establishing a leaky vasculature that lacks a blood–brain barrier. This leaky vasculature enables migration of tumour cells, as well as the build up of fluid, which exacerbates tissue damage due to increased intracranial pressure. Here, we discuss the considerable progress that has been made in the identification of the pro- and antiangiogenic factors produced by glioblastoma tumours and the effects of these molecules in animal models of the disease. The safety and efficacy of some of these approaches have now been demonstrated in clinical trials. However, the ability of tumours to overcome these therapies and to re-establish angiogenesis requires further clinical research regarding potential multimodality therapies, as well as basic research into the regulation of angiogenesis by as yet unidentified factors. Optimisation of noninvasive procedures for monitoring of angiogenesis would greatly facilitate such research.
H3+: the initiator of interstellar chemistry
Authors: Larsson Mats
Published: August 2008

Second only to H2, protonated molecular hydrogen, H3+, is the most abundantly produced interstellar molecule. Owing to its high reactivity and acidity, it plays the pivotal role in initiating interstellar chemical reactions, something which also reduces its steady-state concentration. Interstellar H3+ is not only destroyed in chemical reactions but also in dissociative recombination with electrons. The rate constant and mechanism of recombination have long been controversial, but great advances have been made during recent years, with the important consequence that the cosmic ray ionization rate in diffuse clouds is now believed to be higher by an order of magnitude than previously assumed.
Multistation observations of ELF/VLF whistler mode chorus
Authors: Gołkowski M. , Inan U. S.
Published: August 2008

An array of seven ELF/VLF receivers in Alaska is utilized for direction finding and determination of ionospheric exit point of whistler mode chorus waves from the Earth's magnetosphere. Each receiver records both orthogonal horizontal magnetic components of the chorus waves. All sites use GPS‐synchronized sampling, allowing for the localization of ionospheric exit points utilizing both arrival azimuth and time of arrival lag between sites. Results show two distinct groups of cases, emissions with singular ionospheric exit points and those with multiple exit points. Singular exit point cases exhibit migration and mode conversion as a function of propagation distance from the source point. The multiple exit point case shows chorus waves impinging on the ionosphere over a spread in magnetic latitude, suggesting nonducted propagation. Ray tracing for this case is unable to reproduce the observations unless a cold plasma density different than that predicted by geomagnetic conditions is used. It is proposed that chorus elements cross the transionospheric boundary after experiencing scattering from meter‐scale irregularities. Additionally, subionospheric VLF remote sensing is used to detect precipitation onto the ionosphere of energetic radiation belt electrons that have been pitch angle scattered by individual chorus emission packets. VLF perturbation signatures are consistent with precipitation fluxes being dominated by electrons with energies less than 1 MeV.
Impacts of tidal currents and Kuroshio intrusion on the generation of nonlinear internal waves in Luzon Strait
Authors: Du Tao , Tseng Yu‐Heng , Yan Xiao‐Hai
Published: August 2008

The analysis of remotely sensed images shows that two kinds of nonlinear internal solitary waves (ISWs) in the forms of single ISW and groups of ISWs are commonly seen in Luzon Strait (LS), with larger occurrence during spring tides. A 2‐D numerical model with idealized topography is then used to investigate the generation processes of ISWs in LS. The model results confirm that the ISWs are likely generated during spring tides with strong tidal currents. The results further suggest that the ISWs can be generated by two mechanisms: the evolution of depression and the internal mixing disturbance. Our simulations also show that the Kuroshio intrusion to LS or South China Sea through LS increases the occurrence of generating internal mixing and groups of ISWs. Both remotely sensed images and numerical simulations suggest the existence of a distance between the actual locations where ISWs are generated and where the strongest flow occurs.
Radiometric measurements of ocean surface thermal variability
Authors: Gentemann Chelle L. , Minnett Peter J.
Published: August 2008

Measurements of diurnal temperature variability at the ocean surface have been available primarily from satellite Sea Surface Temperature (SST) retrievals and a small number of ship‐based radiometers. Since most areas are sampled from polar orbiting satellites at most twice a day, surface diurnal variability studies relied on theoretical modeling or extrapolation of results from in situ measurements at depth. The ocean surface responds very rapidly to changes in fluxes of heat and momentum, therefore diurnal variability at the ocean surface may be quite different than heating at depth. Measurements from the Marine Atmospheric Emitted Radiance Interferometer (M‐AERI) provide one of the few skin SST data sets augmented by ancillary measurements necessary for investigations into surface diurnal heating and cooling. This unique data set spans all major ocean basins and contains many days with diurnal warming. The timing of the peak in diurnal warming is directly related to the minimum wind speed and varies from 8:00 to 18:00 local‐mean‐time. Fluctuations in wind speed can result in multiple peaks in diurnal heating during a single afternoon. As wind speed increases, diurnal warming decreases (negatively correlated) and as insolation increases, diurnal warming increases (positively correlated). Changes in wind speed affect diurnal warming amplitudes very rapidly, while changes in insolation have a more gradual effect. The maximum correlation of wind speed (insolation) with changes in diurnal warming is at a time lag of 0 (50) min.
Role of tidally periodic density stratification in the creation of estuarine subtidal circulation
Authors: Stacey Mark T. , Fram Jonathan P. , Chow Fotini K.
Published: August 2008

Tidally periodic stratification is explored as a mechanism for estuarine subtidal flow creation through the use of a numerical water column model. Using a two equation turbulence closure, a tidally periodic steady state is established and the subtidal circulation is calculated. The results demonstrate that the subtidal circulation caused by this forcing is of the same vertical structure as the expected estuarine exchange flow. Further, the subtidal exchange is of similar magnitude to that given by typical scalings of the baroclinic circulation driven by the longitudinal salinity gradient, but is strongly dependent upon the timing of the stratification event within the tidal cycle, even reversing sign for certain phases. The dependence of this subtidal flow mechanism on the local depth, the tidal forcing and the magnitude of the stratification is explored through the use of a bulk Richardson number, for which the subtidal circulation is maximal at intermediate values, and is reduced for both large and small bulk Richardson numbers. This dependence of the subtidal circulation on the bulk Richardson number is demonstrated to be consistent with an analysis of the energetics of mixing and buoyancy on the tidal timescale.
Validation of western and eastern Pacific rainfall estimates from the TRMM PR using a radiative transfer model
Authors: Shige S. , Watanabe T. , Sasaki H. , Kubota T. , Kida S. , Okamoto K.
Published: August 2008

Rainfall estimates from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) facility algorithm over the eastern Pacific are lower than those from the TRMM Microwave Imager (TMI) facility algorithm and a PR‐consistent advanced microwave radiometer algorithm, while they are in good agreement over the western Pacific. We investigate the consistency between TMI‐observed brightness temperatures (TBs) for the 19 GHz channel and those simulated from the PR rainfall estimates using a radiative transfer model. Discrepancies between observed TBs and simulated TBs from the PR are larger for the eastern Pacific than for the western Pacific, indicating that PR underestimates rainfall over the eastern Pacific. It is hypothesized that drop size distributions (DSDs) in the eastern Pacific have stronger maritimity (i.e., more small to medium sized raindrops) than the initial DSD model of the PR algorithm, representative of the “data‐rich” western Pacific, leading to underestimation of rain by the PR. Differences in the adjustable parameter of the PR algorithm, implying changes in the DSD, and the vertical structure of PR‐observed reflectivity over the western and eastern Pacific support the hypothesis.
Antarctic sea ice extent during the Holocene reconstructed from inland ice core evidence
Authors: Iizuka Yoshinori , Hondoh Takeo , Fujii Yoshiyuki
Published: August 2008

Interannual fluctuations in the Antarctic sea ice extent (SIE) affect the global albedo and heat balance, and they may affect global CO2 levels. We found that the annual trend of sodium ion fluxes in the snowpack in the Dome Fuji region of East Antarctica can serve as a proxy for the present‐day SIE in the southern Indian Ocean and Weddell Sea sectors. We then used sodium ion profiles obtained from the Dome Fuji ice core to reconstruct the SIE during the Holocene. We observed that (1) the beginnings of both the climatic optimum (12.0 ka BP) and neoglaciation (5.4 ka BP) in the Southern Ocean, indicated by siliceous microfossil records, are consistent with decreases (11.8 ka BP) and increases (5.4 ka BP) in the sodium ion fluxes in the Dome Fuji ice core, and (2) the interannual fluctuation in the SIE during some periods of the neoglaciation was greater than the interannual fluctuation during the climatic optimum.
Evaluation of ERA‐40, NCEP‐1, and NCEP‐2 reanalysis air temperatures with ground‐based measurements in China
Authors: Ma Lijuan , Zhang Tingjun , Li Qingxiang , Frauenfeld Oliver W. , Qin Dahe
Published: August 2008

We assess the correspondence of reanalysis air temperatures from ERA‐40, NCEP‐1, and NCEP‐2 with homogenized observational data from China for 1958–2001 and 1979–2001. Results indicate that climatologies for annual ERA‐40, NCEP‐1, and NCEP‐2 air temperatures are lower than observations by −0.93°C, −2.78°C, and −2.27°C, respectively. Large negative differences for most of western China primarily contribute to this cool bias. Error analysis indicates that the internal coherence of ERA‐40 data is better than NCEP‐1 or NCEP‐2. Although NCEP‐2 air temperatures represent an improvement over NCEP‐1, biases of NCEP‐1 and NCEP‐2 data relative to observations are still much larger than for ERA‐40. Areas with positive/negative air temperature differences (dT) between reanalysis and observational data correspond to negative/positive elevation differences (dH). The high correlation coefficients of −0.94, −0.88, and −0.85 between dT and dH for ERA‐40, NCEP‐1, NCEP‐2, and observations, respectively, illustrate that the air temperature differences between reanalysis data and observations are primarily related to elevation differences. Furthermore, a spatial and temporal comparison of trends also indicates that ERA‐40 temperature changes correspond most closely to observed trends in China. In general, our comprehensive analysis of the three global reanalysis products indicates that, both on a seasonal and annual basis, ERA‐40 temperatures correspond most closely to observations, and biases are due mainly to the elevation differences.
Sulfur‐induced greenhouse warming on early Mars
Authors: Johnson Sarah Stewart , Mischna Michael A. , Grove Timothy L. , Zuber Maria T.
Published: August 2008

Mineralogical, geological, geophysical, and isotopic data recently returned from Mars suggest that the delivery of sulfur gases to the atmosphere may have played a significant role in the planet's early evolution. Using the Gusev Crater basalt composition and a batch melting model, we obtain a high sulfur solubility, approximately 1400 ppm, in Martian mantle melts. We proceed to explore different scenarios for the pulsed degassing of sulfur volatiles associated with the emplacement of near‐surface dikes during the late Noachian or early Hesperian, when surface pressures are thought to be substantially higher than present. We investigate background Martian atmospheres of 50 and 500 mbar CO2 with varying abundances of H2O and sulfur volatiles (H2S and SO2 mixing ratios of 10−3 to 10−6). Results suggest that these sulfur volatile influxes, alone, could have been responsible for greenhouse warming up to 25 K above that caused by CO2. Including additional water vapor feedback, this process could have raised the early surface temperature above the freezing point for brines and possibly allowed transient liquid water on the Martian surface. Each temperature rise was likely to have been short‐lived, however, due to brief residence times for sulfur volatiles in an optically thin atmosphere.
Dhofar 378 Martian shergottite: Evidence of early shock melting
Authors: Park Jisun , Bogard Donald D. , Mikouchi Takashi , McKay Gordon A.
Published: August 2008

Shock heating of the Dhofar 378 (Dho 378) Martian shergottite produced melting, vesiculation, and flow of the plagioclase, which upon cooling recrystallized into complex textures. Heating experiments on the similar Zagami shergottite indicate that Dho 378 was shock heated to 1000–1100°C and was cooled at ∼2.5°C/h. An 39Ar‐40Ar analysis of Dho 378 plagioclase indicates different Ar diffusion domains and K/Ca ratios. The lower‐temperature phase defines an Ar‐Ar isochron age of 141 ± 32 Ma. The higher‐temperature phase released more 40Ar but does not define an age. The meteorite's thermal history was examined by constructing a generic model to compare cooling rates for objects of different sizes against fractional diffusion loss of Ar for different cooling times. Using gas diffusion parameter values measured for Dho 378, this model indicates that it is improbable that the major shock heating event occurred at the time that Dho 378 was ejected from Mars ∼3 Ma ago. Rather, we suggest that the time of shock heating is probably given by its Ar‐Ar age. For Dho 378 to cool sufficiently fast not to lose most of its 40Ar ∼3 Ma ago would require it to have been ejected into space as an impossibly small object. Larger and more reasonable Mars ejection sizes indicate that Dho 378 should have lost most of its 40Ar. On the basis of plagioclase texture and Ar data, we suggest that a major impact event ∼141 Ma ago melted Dho 378 plagioclase, degassed most of its 40Ar, and deposited it in crater ejecta to cool. A smaller and later impact ejected it into space ∼3 Ma ago.
Bottom water anoxia, inoceramid colonization, and benthopelagic coupling during black shale deposition on Demerara Rise (Late Cretaceous western tropical North Atlantic)
Authors: Jiménez Berrocoso Álvaro , MacLeod Kenneth G. , Calvert Stephen E. , Elorza Javier
Published: August 2008

The bulk rock geochemistry and inoceramid isotopic composition from Cenomanian to Santonian, finely laminated, organic‐rich black shales, recovered during Ocean Drilling Program Leg 207 on Demerara Rise (western tropical North Atlantic), suggest persistent anoxic (free H2S) conditions within the sediments and short‐term variations within a narrow range of anoxic to episodically dysoxic bottom waters over a ∼15 Ma time interval. In addition to being organic‐rich, the 50–90 m thick sections examined exhibit substantial bulk rock enrichments of Si, P, Ba, Cu, Mo, Ni, and Zn relative to World Average Shale. These observations point to high organic burial fluxes, likely driven by high primary production rates, which led to the establishment of intensely sulfidic pore waters and possibly bottom waters, as well as to the enrichments of Cr, Mo, U, and V in the sediments. At the same time, the irregular presence of benthic inoceramids and foraminifera in this facies demonstrates that the benthic environment could not have been continuously anoxic. The δ13C and δ15N values of the inoceramid shell organics provide no evidence of chemosymbiosis and are consistent with pelagic rain as being a significant food source. Demerara Rise inoceramids also exhibit well‐defined, regularly spaced growth lines that are tracked by δ13C and δ18O variations in shell carbonate that cannot be simply explained by diagenesis. Instead, productivity variations in surface waters may have paced the growth of the shells during brief oxygenation events suitable for benthic inoceramid settlement. These inferences imply tight benthopelagic coupling and more dynamic benthic conditions than generally portrayed during black shale deposition. By invoking different temporal scales for geochemical and paleontological data, this study resolves recent contradictory conclusions (e.g., sulfidic sedimentary conditions versus dysoxic to suboxic benthic waters) drawn from studies of either sediment geochemistry or fossil distributions alone on Demerara Rise. This variability may be relevant for discussions of black shales in general.
Dynamic runoff connectivity of overland flow on steep forested hillslopes: Scale effects and runoff transfer
Authors: Gomi Takashi , Sidle Roy C. , Miyata Shusuke , Kosugi Ken'ichirou , Onda Yuichi
Published: August 2008

Both scaling effect and connectivity of overland flow were examined in steep hillslopes covered by (1) Japanese cypress (hinoki, Chamecyparis obtusa) plantations with sparse understory vegetation, (2) hinoki plantations with fern understory vegetation, and (3) deciduous forests. Two sizes of plots were installed for monitoring overland flow: small (0.5 × 2 m) and large hillslope scale (8 × 24–27 m). For all hillslopes, measurable amounts of overland flow occurred during storms. Runoff coefficients of large plots (0.1–3%) were consistently smaller than those of small plots (20–40%). Estimated runoff flow lengths at the hillslope scale were based on runoff coefficients from small plots and were used to calculate runoff volume from large plots. Then we compared the differences between observed and estimated runoff volumes of large plots. Estimated runoff from large plots was smaller than observed runoff in hinoki slopes with sparse understory vegetation. Greater amounts of observed compared to estimated overland flow suggest that more runoff occurred from hillslopes with sparse understory. In contrast, estimated overland flow was larger than observed runoff from the deciduous forest, implying greater opportunities for infiltration compared to hinoki hillslopes. Comparison of estimated versus observed overland flow for successive 5 min intervals during storms indicates that runoff networks expand upslope during short and intense precipitation periods. Our examination and comparison of storm runoff from small and large plots facilitate better understanding of runoff mechanisms, scaling effects in hillslopes, and connectivity of the overland flow network.
Scale‐dependent desorption of uranium from contaminated subsurface sediments
Authors: Liu Chongxuan , Zachara John M. , Qafoku Nikolla P. , Wang Zheming
Published: August 2008

Column experiments were performed to investigate the scale‐dependent desorption of uranyl [U(VI)] from a contaminated sediment collected from the Hanford 300 Area at the U.S. Department of Energy (DOE) Hanford Site, Washington. The sediment was a coarse‐textured alluvial flood deposit containing significant mass percentage of river cobble. U(VI) was, however, only associated with its minor fine‐grained (<2 mm) mass fraction. U(VI) desorption was investigated both from the field‐textured sediment using a large column (80 cm length by 15 cm inner diameter) and from its <2 mm U(VI)‐associated mass fraction using a small column (10 cm length by 3.4 cm inner diameter). Dynamic advection conditions with intermittent flow and stop‐flow events of variable durations were employed to investigate U(VI) desorption kinetics and its scale dependence. A multicomponent kinetic model that integrated a distributed rate of mass transfer with surface complexation reactions successfully described U(VI) release from the fine‐grained U(VI)‐associated materials. The field‐textured sediment in the large column displayed dual‐domain tracer‐dependent mass transfer properties that affected the breakthrough curves of bromide, pentafluorobenzoic acid (PFBA), and tritium. The tritium breakthrough curve showed stronger nonequilibrium behavior than did PFBA and bromide and required a larger immobile porosity to describe. The dual‐domain mass transfer properties were then used to scale the kinetic model of U(VI) desorption developed for the fine‐grained materials to describe U(VI) release and reactive transport in the field‐textured sediment. Numerical simulations indicated that the kinetic model that was integrated with the dual‐domain properties determined from tracer PFBA and Br best described the experimental results. The kinetic model without consideration of the dual‐domain properties overpredicted effluent U(VI) concentrations, while the model based on tritium mass transfer underpredicted the rate of U(VI) release. Overall, our results indicated that the kinetics of U(VI) release from the field‐textured sediment were different from that of its fine‐grained U(VI)‐associated mass fraction. However, the desorption kinetics measured on the U(VI)‐containing mass fraction could be scaled to describe U(VI) reactive transport in the contaminated field‐textured sediment after proper consideration of the physical transport properties of the sediment. The research also demonstrated a modeling approach to integrate geochemical processes into field‐scale reactive transport models.
Statistical analysis of corotating interaction regions and their geoeffectiveness during solar cycle 23
Authors: Zhang Y. , Sun W. , Feng X. S. , Deehr C. S. , Fry C. D. , Dryer M.
Published: August 2008

This is an investigation of the effects of corotating interaction regions (CIRs) in the heliosphere (<1 AU) on geomagnetic disturbances during solar cycle 23 (1996–2005). Three kinds of interplanetary structures, “pure” CIR, interaction of CIR with ICME, and “pure” ICME by transient events, are identified by using the Hakamada‐Akasofu‐Fry (HAF) solar wind model. Yearly occurrence of 157 “pure” CIRs has a minimum value in 2001 and a peak value in 2003 at the declining phase during the 23rd solar cycle. The maximum correlation coefficient of the daily sum of Kp indices between consecutive Carrington Rotations indicates that recurrent geomagnetic disturbances are dominant during the declining phase near solar minimum. Eighty percent of storms that are related to “pure” CIRs belong to weak and moderate storms. The statistical analysis shows that about 50% of CIRs produce classical interplanetary shocks during the descending phase and 89% of the CIR‐related shocks are followed by geomagnetic storms. These results demonstrate that CIR‐related shock is not a necessary condition for generating a magnetic storm, but most CIR‐related shocks are related to a storm. The Dst index that corresponds to CIR‐related storms has a better linear relationship with IMF Bz, Ey, and the coupling function (ɛ) when the Dst indices are higher than −100 nT. Finally, the geoeffectiveness of CIRs appears clearly to have a seasonal variation.
Solar concept of flux transport by interchange reconnection applied to the magnetosphere
Authors: Merkin V. G. , Crooker N. U.
Published: August 2008

The traditional concept of steady state convection of magnetic field‐line foot points in Earth's ionosphere driven by reconnection between the interplanetary and geomagnetic fields implies that those foot points follow closed contours of circulation. Remote reconnection that occurs when the foot points cross the polar cap boundary controls whether the field lines are open or closed, but the foot points remain firmly rooted to their paths around the closed circulation cells. In steady state MHD models, however, this concept of convection breaks down owing to interchange reconnection between open and closed field lines. In the solar heliospheric community, interchange reconnection has long been understood as a means of flux transport. In the magnetosphere, flux transport by interchange reconnection causes field‐line foot points to jump, or saltate, from one side of the polar cap to the other as part of the steady state circulation. We develop a definitive method for identifying interchange reconnection in an MHD model and illustrate the resultant foot point saltation.
El Niño–Southern Oscillation signals in sea level, surface mass redistribution, and degree‐two geoid coefficients
Authors: Landerer Felix W. , Jungclaus Johann H. , Marotzke Jochem
Published: August 2008

We use a coupled Earth system model to simulate and quantify the impact of the El Niño–Southern Oscillation (ENSO) on monthly to interannual variations of steric and eustatic global mean sea level (GMSL), surface mass loading, and on the corresponding degree‐two geoid coefficients (C21, S21, and C20). GMSL is dominated by eustatic variations on monthly to interannual timescales, but less than 10% of the eustatic variance is related to ENSO. In contrast, steric GMSL correlates linearly in phase with ENSO with an explained variance of nearly 46%. Together these results imply that total GMSL variations are only weakly correlated with ENSO. Despite this small correlation, we find a distinct ENSO pattern of sizable surface mass load anomalies. Over the continents, this pattern is similar to typical ENSO‐related precipitation anomalies. Over the oceans, the pattern features a global, albeit weaker, response, with generally increased loading in the Arctic and Pacific oceans, and decreased loading in the Atlantic and Indian oceans. These surface loading anomalies lead to statistically significant ENSO‐related variations in the S21 and C20 geoid coefficients, but not in C21. In analyzing the individual subsystem contributions, we find that S21 is influenced by both ocean mass redistribution and soil moisture loading, whereas C20 is mainly influenced by soil moisture loading. Our results highlight the importance of high‐amplitude regional loading anomalies that integrate to low‐degree geoid anomalies.
Multisensor satellite observations of aerosol effects on warm clouds
Authors: Lebsock Matthew D. , Stephens Graeme L. , Kummerow Christian
Published: August 2008

A global multisensor satellite examination of aerosol indirect effects on warm oceanic clouds is presented. The study centers on the water path response of cloud to aerosol burden. A unique element of the study is a rigorous rain screening methodology that is utilized to separate the responses of nonraining and raining clouds. It is demonstrated that high aerosol environments are associated with reduced liquid water path in nonprecipitating clouds and that the reduction in liquid water path reduces the albedo enhancement expected from decreasing effective radius. Furthermore the reduction in liquid water path is greater in thermodynamically unstable environments than in stable environments suggesting a greater sensitivity of cumulus cloud than stratiform cloud liquid water path to aerosol. In sharp contrast with nonprecipitating clouds, the cloud liquid water path of transitional and precipitating clouds increases dramatically with aerosol, which may be indicative of an inhibited coalescence process. The evidence further indicates that increasing aerosol requires greater amounts of cloud condensate before the onset of precipitation. Additional support for this hypothesis is found in a reduction in the probability of precipitation by as much as 10% depending on the thermodynamical state of the environment. Independent estimates of the broadband cloudy‐sky albedo are used to confirm that the cloud albedo responds to the trends that are identified in the liquid water path. In particular, it is found that the water path effect dominates the cloud albedo response for precipitating and transitional clouds. Finally, regional analysis demonstrates that the magnitude of the relationship between aerosol and cloud albedo is greatest in the extratropics and subtropical stratus regions primarily in the winter hemisphere. These relationships are used to estimate the magnitude of the first indirect effect as −0.42 W/m2.
Carbon dioxide electron cooling rates in the atmospheres of Mars and Venus
Authors: Campbell L. , Brunger M. J. , Rescigno T. N.
Published: August 2008

The cooling of electrons in collisions with carbon dioxide in the atmospheres of Venus and Mars is investigated. Calculations are performed with both previously accepted electron energy transfer rates and with new ones determined using more recent theoretical and experimental cross sections for electron impact on CO2. Emulation of a previous model for Venus confirms the validity of the current model and shows that use of the updated cross sections leads to cooling rates that are lower by one third. Application of the same model to the atmosphere of Mars gives more than double the previous cooling rates at altitudes where the electron temperature is very low.
Towards a taxonomy of movement patterns
Authors: Dodge Somayeh , Weibel Robert , Lautenschütz Anna-Katharina
Published: August 2008

Areview of research that has been carried out on data mining and visual analysis of movement patterns suggests that there is little agreement on the relevant types of movement patterns and only few, isolated definitions of these exist. Since the research interest in this area has recently started to soar, we believe that this is a good time to approach the definition of movement patterns in a more systematic and comprehensive way. This paper intends to contribute to the development of a toolbox of data mining algorithms and visual analytic techniques for movement analysis by developing firstly a conceptual frame-work for movement behavior of different moving objects and secondly a comprehensive classification and review of movement patterns. We argue that this is indispensable as a basis for the development of pattern recognition and information visualization algorithms that are required to be efficient (i.e. usable on massive data sets), effective (i.e. capable of accurately detecting patterns not artifacts), and as generic as possible (i.e. potentially applicable to different types of movement data). We demonstrate the utilization of our classification by answering the question as to what extent eye tracking data can be seen as a proxy of other types of movement data. We have set up a moderated discussion platform in order to facilitate the further evolution of our proposed classification towards a consolidated taxonomy in a consensus process.
Cell viscoelastic characterization using photoacoustic measurement
Authors: Li Jianghua , Tang Zhilie , Xia Yunfei , Lou Yanfei , Li Guanghua
Published: August 2008

Photoacoustic (PA) measurement is noninvasive. We used the PA technique to measure the viscoelasticity of red blood cells (RBCs) to determine whether it could elucidate mechanical characteristics at a cellular level. A single-pulse laser beam was used as the light source to generate a PA signal. A “thin” glass was used as an acoustical impedance medium to form the attenuation signal. From the amplitude attenuation curves of the signals of a control RBC group and some glutaraldehyde-treated RBC groups, we obtained the decay times. As decay time is equal to the viscosity-elasticity ratio, we could obtain the viscoelasticity characteristics of the RBC. The PA technique is a simple, real-time, and noninvasive way to acquire the viscoelastic properties at a cellular level.
Why the long-term charge offset drift in Si single-electron tunneling transistors is much smaller (better) than in metal-based ones: Two-level fluctuator stability
Authors: Zimmerman Neil M. , Huber William H. , Simonds Brian , Hourdakis Emmanouel , Fujiwara Akira , Ono Yukinori , Takahashi Yasuo , Inokawa Hiroshi , Furlan Miha , Keller Mark W.
Published: August 2008

A common observation in metal-based (specifically, those with AlOx tunnel junctions) single-electron tunneling (SET) devices is a time-dependent instability known as the long-term charge offset drift. This drift is not seen in Si-based devices. Our aim is to understand the difference between these, and ultimately to overcome the drift in the metal-based devices. A comprehensive set of measurements shows that (1) brief measurements over short periods of time can mask the underlying drift, (2) we have not found any reproducible technique to eliminate the drift, and (3) two-level fluctuators (TLFs) in the metal-based devices are not stable. In contrast, in the Si-based devices the charge offset drifts by less than 0.01e over many days, and the TLFs are stable. We also show charge noise measurements in a SET device over four decades of temperature. We present a model for the charge offset drift based on the observation of nonequilibrium heat evolution in glassy materials, and obtain a numerical estimate in good agreement with our charge offset drift observations. We conclude that, while the Si devices are not perfect and defect-free, the defects are stable and noninteracting; in contrast, the interacting, unstable glasslike defects in the metal-based devices are what lead to the charge offset drift. We end by suggesting some particular directions for the improvement in fabrication, and in particular, fabrication with crystalline metal-oxide barriers, that may lead to charge offset drift-free behavior.
Effect of smectic A temperature width on the soft mode in ferroelectric liquid crystals
Authors: Choudhary A. , Kaur S. , Prakash J. , Sreenivas K. , Bawa S. S. , Biradar A. M.
Published: August 2008

The behavior of soft mode range with respect to the temperature width of smectic A (Sm A) phase has been studied in four different ferroelectric liquid crystal (FLC) materials in the frequency range 10Hz–10MHz. The studies have been carried out in a planarly well aligned cells at different temperatures and different bias fields in Sm C* and Sm A phases. Dielectric studies of these FLCs near Sm C*-Sm A phase transition show that the temperature range of soft mode relaxation frequency phenomenon varies with the temperature width of Sm A phase. The dependence of tilt angle on temperature shows the nature of the order of transition at Sm C*-Sm A phase. The coupling between order parameters of Sm C* and Sm A phase influences the soft mode and phase transition in Sm C* and Sm A phases.
Minimal length uncertainty relations and new shape invariant models
Authors: Spector Donald
Published: August 2008

This paper identifies a new class of shape invariant models. These models are based on extensions of conventional quantum mechanics that satisfy a string-motivated minimal length uncertainty relation. An important feature of our construction is the pairing of operators that are not adjoints of each other. The results in this paper thus show the broader applicability of shape invariance to exactly solvable systems.
An extended procedure for finding exact solutions of partial differential equations arising from potential symmetries. Applications to gas dynamics
Authors: Cheviakov Alexei F.
Published: August 2008

Lie point symmetries and nonlocal symmetries of partial differential equation (PDE) systems are widely used for construction of exact invariant solutions. In this paper we describe an extended algorithmic procedure that, for a given nonlocal (potential) symmetry, can yield additional exact solutions, which cannot be found using the usual algorithm. In particular, such additional solutions are exact solutions of the given PDE system, but are not invariant solutions of the corresponding potential system. As an example, we consider a tree of nonlocally related PDE systems for Lagrange planar gas dynamics equations and classify its nonlocal symmetries for an ideal polytropic gas. For two different nonlocal symmetries of the Lagrange system, we demonstrate that the extended method yields wider classes of exact solutions than the usual method.
Nonuniform liquid-crystalline phases of parallel hard rod-shaped particles: From ellipsoids to cylinders
Authors: Martínez-Ratón Y. , Velasco E.
Published: August 2008

In this article we consider systems of parallel hard superellipsoids, which can be viewed as a possible interpolation between ellipsoids of revolution and cylinders. Superellipsoids are characterized by an aspect ratio and an exponent α (shape parameter) which takes care of the geometry, with α=1 corresponding to ellipsoids of revolution, while α=∞ is the limit of cylinders. It is well known that, while hard parallel cylinders exhibit nematic, smectic, and solid phases, hard parallel ellipsoids do not stabilize the smectic phase, the nematic phase transforming directly into a solid as density is increased. We use computer simulation to find evidence that for α⩾αc, where αc is a critical value which the simulations estimate to be approximately 1.2–1.3, the smectic phase is stabilized. This is surprisingly close to the ellipsoidal case. In addition, we use a density-functional approach, based on the Parsons–Lee approximation, to describe smectic and columnar orderings. In combination with a free-volume theory for the crystalline phase, a theoretical phase diagram is predicted. While some qualitative features, such as the enhancement of smectic stability for increasing α and the probable absence of a stable columnar phase, are correct, the precise location of coexistence densities is quantitatively incorrect.