bluuebunny/crossref_metadata_2025 huggingface dataset:
Concentrations and origins of atmospheric lead and other trace species at a rural site in northern China
Authors: Li Can , Wen Tianxue , Li Zhanqing , Dickerson Russell R. , Yang Yongjie , Zhao Yanan , Wang Yuesi , Tsay Si‐Chee
Published: October 2010

In this study we analyze the ambient levels of lead and other trace species in the bulk aerosol samples from a rural site ∼70 km ESE of Beijing in spring 2005. Lead (0.28 ± 0.24 μg/m3, average ± standard deviation), along with several pollution‐related trace elements, was enriched by over 100 fold relative to the Earth’s crust. The ambient lead levels showing large synoptic variations were well‐correlated with other anthropogenic pollutants (e.g., CO and SO2). The Unmix receptor model resolved four factors in the aerosol composition data: a biomass burning source, an industrial and coal combustion source, a secondary aerosol source, and a dust source. The first three sources were strongest in weak southerly winds ahead of cold fronts, while the dust source peaked in strong northerly winds behind cold fronts. The second source, primarily representing emissions from industrial processes and relatively small‐scale coal burning such as in home and institutional heating, was identified as the main source of ambient lead in this study. Mobile sources might also contribute to this factor, but there was no distinct evidence of emissions due to combustion of leaded gasoline, despite a correlation between lead and CO. Potential source contribution function, calculated from backward trajectories and aerosol composition, further reveals that lead observed in this study was predominantly from the populated and industrialized areas to the south and SW of Xianghe, rather than Beijing to the west. Our results and several recent studies show that the lead levels in suburban areas near big cities in China, although generally lower than those in industrial districts and urban areas, are substantial (near or above 0.15 μg/m3). More extensive studies on airborne lead and its emission sources in China are called for.
Spatial relationships between soil moisture patterns and topographic variables at multiple scales in a humid temperate forested catchment
Authors: Ali Geneviève A. , Roy André G. , Legendre Pierre
Published: October 2010

New tools are needed in hydrology to improve our understanding of process heterogeneity and its relationship to catchment topography. We tested the distance‐based Moran's eigenvector maps (DBMEM) method, which models patterns using a combination of positively and negatively autocorrelated structures, searching for soil moisture characteristic scales in a temperate humid forested system. We focused on three questions: (1) What are the characteristic spatial scales of shallow soil moisture? (2) Is there a strong relationship between soil moisture patterns and topographic variables at these scales? and (3) Which hydro‐meteorological variables influence soil moisture scales and topographic controls in a significant way? Data consisted of 16 surveys of soil moisture at depths of 5, 15, 30, and 45 cm in the 5.1 ha Hermine catchment (Laurentians, Canada). The global DBMEM model explained 21 to 96% (adjusted R square) of the spatial variations in soil moisture apportioned into decreasing fractions over six spatially nested, additive submodels: very large (0.85–1.4 ha), large (0.54–0.85 ha), meso (0.50–0.54 ha), fine positive (0.22–0.50 ha), fine negative (0.10–0.22 ha), and very fine (0.02–0.10 ha). The effects of catchment topography (e.g., slope and contributing area) on soil moisture were significant at large and very large scales. Moisture patterns at these scales were dependent on previous storm properties and were good predictors of catchment response. The DBMEM approach provided insightful quantitative evidence regarding the temporal dependency of the relationships between dynamic soil moisture content and static topographic variables across scales.
Hillslope hydrologic connectivity controls riparian groundwater turnover: Implications of catchment structure for riparian buffering and stream water sources
Authors: Jencso Kelsey G. , McGlynn Brian L. , Gooseff Michael N. , Bencala Kenneth E. , Wondzell Steven M.
Published: October 2010

Hydrologic connectivity between catchment upland and near stream areas is essential for the transmission of water, solutes, and nutrients to streams. However, our current understanding of the role of riparian zones in mediating landscape hydrologic connectivity and the catchment scale export of water and solutes is limited. We tested the relationship between the duration of hillslope‐riparian‐stream (HRS) hydrologic connectivity and the rate and degree of riparian shallow groundwater turnover along four HRS well transects within a set of nested mountain catchments (Tenderfoot Creek Experimental Forest, MT). Transect HRS water table connectivity ranged from 9 to 123 days during the annual snowmelt hydrograph. Hillslope water was always characterized by low specific conductance (∼27 μS cm−1). In transects with transient hillslope water tables, riparian groundwater specific conductance was elevated during base flow conditions (∼127 μS cm−1) but shifted toward hillslope signatures once a HRS groundwater connection was established. The degree of riparian groundwater turnover was proportional to the duration of HRS connectivity and inversely related to the riparian: hillslope area ratios (buffer ratio; r2 = 0.95). We applied this relationship to the stream network in seven subcatchments within the Tenderfoot Creek Experimental Forest and compared their turnover distributions to source water contributions measured at each catchment outlet. The amount of riparian groundwater exiting each of the seven catchments was linearly related (r2 = 0.92) to their median riparian turnover time. Our observations suggest that the size and spatial arrangement of hillslope and riparian zones along a stream network and the timing and duration of groundwater connectivity between them is a first‐order control on the magnitude and timing of water and solutes observed at the catchment outlet.
Salt marsh–atmosphere exchange of energy, water vapor, and carbon dioxide: Effects of tidal flooding and biophysical controls
Authors: Moffett Kevan B. , Wolf Adam , Berry Joe A. , Gorelick Steven M.
Published: October 2010

The degree to which short‐duration, transient floods modify wetland‐atmosphere exchange of energy, water vapor, and carbon dioxide (CO2) is poorly documented despite the significance of flooding in many wetlands. This study explored the effects of transient floods on salt marsh–atmosphere linkages. Eddy flux, micrometeorological, and other field data collected during two tidal phases (daytime versus nighttime high tides) quantified the salt marsh radiation budget, surface energy balance, and CO2 flux. Analysis contrasted flooded and nonflooded and day and night effects. The salt marsh surface energy balance was similar to that of a heating‐dominated sparse crop during nonflooded periods but similar to that of an evaporative cooling‐dominated, well‐watered grassy lawn during flooding. Observed increases in latent heat flux and decreases in net ecosystem exchange during flooding were proportional to flood depth and duration, with complete CO2 flux suppression occurring above some flood height less than the canopy height. Flood‐induced changes in the salt marsh energy balance were dominated by changes in sensible heat flux, soil heat flux, and surface water heat storage. Parameters suitable for predicting the salt marsh surface energy balance were obtained by calibrating common models (e.g., Penman‐Monteith, Priestley‐Taylor, and pan coefficient). Biophysical controls on salt marsh–atmosphere exchange were identified following calibration of models describing the coupling of canopy photosynthesis and stomatal conductance in the salt marsh. The effects of flooding on salt marsh–atmosphere exchange are temporary but strongly affect the marsh water, carbon, and energy balance despite their short duration.
Origin of cross‐chain geochemical variation in Quaternary lavas from the northern Izu arc: Using a quantitative mass balance approach to identify mantle sources and mantle wedge processes
Authors: Kimura Jun‐Ichi , Kent Adam J. R. , Rowe Michael C. , Katakuse Maiko , Nakano Fumi , Hacker Bradley R. , van Keken Peter E. , Kawabata Hiroshi , Stern Robert J.
Published: October 2010

We present major, trace element, and Pb‐Sr‐Nd‐Hf isotope data for Quaternary basalt and basaltic andesite lavas from cross‐chain volcanoes in the northern Izu (N‐Izu) arc. Lavas from Izu‐Oshima, Toshima, Udonejima, and Niijima islands show consistent chemical changes with depth to the Wadati‐Benioff zone, from 120 km beneath Izu‐Oshima to 180 km beneath Niijima. Lavas from Izu‐Oshima at the volcanic front (VF) have elevated concentrations of large ion lithophile elements (LILEs), whereas rear‐arc (RA) lavas are rich in light rare earth elements (LREEs) and high field strength elements (HFSEs). VF lavas also have more radiogenic Pb, Nd, Sr, and Hf isotopic compositions. We have used the Arc Basalt Simulator version 3 (ABS3) to examine the mass balance of slab dehydration and melting and slab fluid/melt‐fluxed mantle melting and to quantitatively evaluate magma genesis beneath N‐Izu. The results suggest that the slab‐derived fluids/melts are derived from ∼20% sediment and ∼80% altered oceanic crust, the slab fluid is generated by slab dehydration for the VF magmas at 3.3–3.5 GPa/660°C–700°C, and slab melt for RA magmas is supplied at 3.4–4.4 GPa/830°C–890°C. The degree of fluxed melting of the mantle wedge varies between 17% and 28% (VF) and 6% and 22% (RA), with a slab flux fraction of 2%–4.5% (VF fluid) to 1%–1.5% (RA melt), and at melting depths 1–2.5 GPa (VF) and 2.4–2.8 GPa (RA). These conditions are consistent with a model whereby shallow, relatively low temperature slab fluids contribute to VF basalt genesis, whereas deeper and hotter slab melts control formation of RA basalts. The low‐temperature slab dehydration is the cause of elevated Ba/Th in VF basalt due mainly to breakdown of lawsonite, whereas deeper breakdown of phengite by slab melting is the cause of elevated K and Rb in RA basalts. Melting in the garnet stability field, and at lower degrees of partial melting, is required for the elevated LILEs, LREEs, and HFSEs observed in the RA basalts. Less radiogenic Sr, Nd, Hf, and Pb in RA basalts are all attributable to lesser slab flux additions. The low H2O predicted for RA basalt magmas (<1.5 wt %) relative to that in VF basalt magmas (5–8 wt %) is also due to melt addition rather than fluid. All these conclusions are broadly consistent with existing models; however, in this study they are quantitatively confirmed by the geochemical mass balance deduced from petrological ABS3 model. Overall, the P‐T‐X(H2O) structure of the slab and the mantle wedge exert the primary controls on arc basalt genesis.
Toward understanding the large‐scale land‐atmosphere coupling in the models: Roles of different processes
Authors: Wei Jiangfeng , Dirmeyer Paul A.
Published: October 2010

Two different Atmospheric General Circulation Models (AGCMs), each coupled to three different land surface schemes (LSSs) (six different model configurations in total), are used to study the roles of different model components and different action processes in land‐atmosphere coupling. Experiments show that, for the six model configurations, the choice of AGCMs is the main reason for the substantially different precipitation variability, predictability, and land‐atmosphere coupling strength among the configurations. The impact of different LSSs is secondary. Intraseasonal precipitation variability, which is mainly a property of the AGCM, can impact land‐atmosphere coupling both directly in the atmosphere and indirectly through soil moisture response to precipitation. These results lead to a common conceptual decomposition of the land‐atmosphere coupling strength and increases the understanding on large‐scale land‐atmosphere coupling.
CMI growth rates for Saturnian kilometric radiation
Authors: Mutel R. L. , Menietti J. D. , Gurnett D. A. , Kurth W. , Schippers P. , Lynch C. , Lamy L. , Arridge C. , Cecconi B.
Published: October 2010

We calculate growth rates for extraordinary mode Saturnian kilometric radiation generated by the electron cyclotron maser instability using a ring‐type (DGH) electron phase distribution model fitted to measured electron energy distributions in Saturn's auroral acceleration region. The observed distributions are unstable in spatially isolated regions of transverse linear size of order 103 km. Each unstable region has a growth rate consistent with amplification of background radiation to the peak observed intensity, approximately 14 electric field e‐foldings. The observed propagation direction and frequency decrement below the electron cyclotron frequency are also consistent with the CMI growth model.
On the resolution of shallow mantle viscosity structure using postearthquake relaxation data: Application to the 1999 Hector Mine, California, earthquake
Authors: Pollitz Fred F. , Thatcher Wayne
Published: October 2010

Most models of lower crust/mantle viscosity inferred from postearthquake relaxation assume one or two uniform‐viscosity layers. A few existing models possess apparently significant radially variable viscosity structure in the shallow mantle (e.g., the upper 200 km), but the resolution of such variations is not clear. We use a geophysical inverse procedure to address the resolving power of inferred shallow mantle viscosity structure using postearthquake relaxation data. We apply this methodology to 9 years of GPS‐constrained crustal motions after the 16 October 1999 M = 7.1 Hector Mine earthquake. After application of a differencing method to isolate the postearthquake signal from the “background” crustal velocity field, we find that surface velocities diminish from ∼20 mm/yr in the first few months to ≲2 mm/yr after 2 years. Viscoelastic relaxation of the mantle, with a time‐dependent effective viscosity prescribed by a Burgers body, provides a good explanation for the postseismic crustal deformation, capturing both the spatial and temporal pattern. In the context of the Burgers body model (which involves a transient viscosity and steady state viscosity), a resolution analysis based on the singular value decomposition reveals that at most, two constraints on depth‐dependent steady state mantle viscosity are provided by the present data set. Uppermost mantle viscosity (depth ≲ 60 km) is moderately resolved, but deeper viscosity structure is poorly resolved. The simplest model that explains the data better than that of uniform steady state mantle viscosity involves a linear gradient in logarithmic viscosity with depth, with a small increase from the Moho to 220 km depth. However, the viscosity increase is not statistically significant. This suggests that the depth‐dependent steady state viscosity is not resolvably different from uniformity in the uppermost mantle.
Influence of a future climate on the microphysical and optical properties of orographic cirrus clouds in ECHAM5
Authors: Joos H. , Spichtinger P. , Lohmann U.
Published: October 2010

The European Centre/Hamburg 5 (ECHAM5) general circulation model is used in order to investigate the influence of a warmer climate on the microphysical and optical properties of orographic cirrus clouds. The main goal of this study is to highlight the variety of processes influencing the formation of orographic cirrus and to emphasize the importance of coupling dynamics and cloud microphysics in order to provide realistic predictions of the influence of a future climate on cloud microphysical and radiative properties. Therefore, a coupling of gravity wave dynamics and cloud microphysics is implemented in the model. The influence of additional moisture on the propagation of gravity waves is investigated by using the dry and moist Brunt‐Väisäla frequency in the calculation of the gravity wave‐induced vertical velocity in two different simulations. In both simulations, the vertical velocities increase in the warmer climate. The additional moisture decreases the Brunt‐Väisäla frequencies leading to less flow blocking and thus higher effective mountain heights. As this effect dominates over the decrease of the gravity wave amplitude due to more moisture, higher vertical velocities occur in a future climate. The opposite effect of a decreased vertical velocity in a future climate can be seen over the dry regions. From the present to the future climate, the ice crystal number concentration decreases despite the increased vertical velocities. Higher temperatures lead to a faster growth of the ice crystals, and the supersaturation is depleted faster such that no new crystals can be formed. The ice water content increases as more water vapor is available in a warmer climate. The net effect of a decreased ice crystal number concentration and an increased ice water content is an increased optical depth in a future climate. This result is in good agreement with recent cloud resolving studies. The effect of orographic cirrus clouds on the radiation is given by an increased short‐ and long‐wave cloud forcing, whereas the latter dominates. However, from the present to the future climate, no changes in orographic cloud cover and cloud forcing over mountains can be seen.
Trends in tropospheric humidity from reanalysis systems
Authors: Dessler A. E. , Davis S. M.
Published: October 2010

A recent paper (Paltridge et al., 2009) found that specific humidity in the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis declined between 1973 and 2007, particularly in the tropical mid and upper troposphere, the region that plays the key role in the water vapor feedback. If borne out, this result suggests potential problems in the consensus view of a positive water vapor feedback. Here we consider whether this result holds in other reanalyses and what time scale of climate fluctuation is associated with the negative specific humidity trends. The five reanalyses analyzed here (the older NCEP/NCAR and ERA40 reanalyses and the more modern Japanese Reanalysis (JRA), Modern Era Retrospective‐Analysis for Research and Applications (MERRA), and European Centre for Medium‐Range Weather Forecasts (ECMWF)‐interim reanalyses) unanimously agree that specific humidity generally increases in response to short‐term climate variations (e.g., El Niño). In response to decadal climate fluctuations, the NCEP/NCAR reanalysis is unique in showing decreases in tropical mid and upper tropospheric specific humidity as the climate warms. All of the other reanalyses show that decadal warming is accompanied by increases in mid and upper tropospheric specific humidity. We conclude from this that it is doubtful that these negative long‐term specific humidity trends in the NCEP/NCAR reanalysis are realistic for several reasons. First, the newer reanalyses include improvements specifically designed to increase the fidelity of long‐term trends in their parameters, so the positive trends found there should be more reliable than in the older reanalyses. Second, all of the reanalyses except the NCEP/NCAR assimilate satellite radiances rather than being solely dependent on radiosonde humidity measurements to constrain upper tropospheric humidity. Third, the NCEP/NCAR reanalysis exhibits a large bias in tropical upper tropospheric specific humidity. And finally, we point out that there exists no theoretical support for having a positive short‐term water vapor feedback and a negative long‐term one.
A Meta-analysis of Studies on Plant Growth Rate and Allocation to Roots and Shoots
Authors: Taub Daniel
Published: October 2010

I performed a meta-analysis of studies examining the relationships among nutrient availability, plant growth rate and allocation to roots vs. shoots. Species characteristic of high fertility habits grew faster than species characteristic of less fertile habitats. While species were highly plastic in root/shoot ratio, there was a strong correlation in root/shoot across fertility levels when plants were grown across fertility gradients. This suggests that the proportional mass allocation to roots is a consistent characteristic of individual species relative to other species. There was no consistent relationship between allocation to roots and either growth rate or the fertility of habitats that species typically are found in.
Standards and infrastructure for managing experimental metadata
Authors: Evans Richard , Sansone Susanna-Assunta , Rocca-Serra Philippe , Brandizi Marco , Maguire Eamonn , Sklyar Nataliya , Taylor Chris , Delahaye Manon
Published: October 2010

*See also the "related presentation":http://precedings.nature.com/documents/3145/version/1*We present an infrastructure that leverages synergistic reporting standards and ontologies^1,2,3,4,5^ to create a common structured representation and storage mechanism for experimental metadata from biological and biomedical investigations ranging from simple single-assay studies to complex, methodologically diverse multi-assay studies.The infrastructure’s components include: a data capture and editing tool (ISAcreator); validator (ISAvalidator); database (BioInvestigation Index); and converter (ISAconverter); and a BioConductor analysis package (R-ISApackage). The components are designed for local installation, and can work independently, or as unified system.View the "public instance":http://www.ebi.ac.uk/bioinvindex running at EBI and/or "download the components":http://isatab.sf.net for your local use.*References*1. Taylor CF, Field D, Sansone SA,… Rocca-Serra P et al. (2008) The MIBBI Project. Nature Biotechnology Aug;26(8):889-896. "http://www.mibbi.org":http://www.mibbi.org2. Smith B, Ashburner M, Rosse C,… Rocca-Serra P, …Sansone SA et al. (2007) The OBO Foundry. Nature Biotechnology Nov;25(11):1251-5. "http://www.obofoundry.org":http://www.obofoundry.org3. Ontology for Biomedical Investigations (OBI) "http://obi-ontology.org":http://obi-ontology.org4. Sansone SA, Rocca-Serra P, Brandizi M,… Taylor CF et al. (2008) The First MGED RSBI (ISA-TAB) Workshop. OMICS. Jun;12(2):143-9. "http://isatab.sf.net":http://isatab.sf.net5. Jones AR, Miller M, Aebersold R,… Sansone SA et al. (2007) The Functional Genomics Experiment model (FuGE). Nature Biotechnology Oct;25(10):1127-1133. "http://fuge.sf.net":http://fuge.sf.net
Worm Annotation in the UniProt Knowledgebase (UniProtKB)
Authors: Legge Duncan , Consortium UniProt
Published: October 2010

The nematode worm, Caenorhabditis elegans, was the first multicellular organism to be sequenced. Its genome was published in 1998, providing an impetus for gene and protein annotation. Recently, the genome of C. briggsae has been sequenced. This has given bioinformaticans the opportunity to study comparative genomics between two highly similar organisms. Currently, there are 12 species of Caenorhabditis in UniProtKB and over 700 nematode species, including some of interest to parasitology. Functional and sequence annotation from literature and sequence analysis tools are included in each curated record. C. elegans has a relatively small genome size, short life span and a transparent body, making it ideal for knock-out/RNAi studies. Thus many C. elegans UniProtKB entries have characterization details in the newly introduced DISRUPTION PHENOTYPE comment. Many more worm genome sequencing projects are underway, three of which involve species from the Caenorhabditis genus (C. brenneri, C. japonica and C.remanei). We look forward to working with this influx of data and continuing our close collaboration with WormBase.
Normalization and Matching of Chemical Compound Names
Authors: Golebiewski Martin , Šarić Jasmin , Engelken Henriette , Bittkowski Meik , Wittig Ulrike , Müller Wolfgang , Rojas Isabel
Published: October 2010

The identification of a chemical compound solely based on its name requires comprehensive chemical knowledge and often extensive searches in chemical databases. However, it is crucial for the integration of biochemical data extracted from the literature, since many publications exclusively describe a compound by its name. We have developed an application which matches synonymic names of chemical compounds and thereby facilitates the bundling of corresponding data referring to the same compound.The tool that we have developed is based on natural language processing (NLP) methods and applies rules to systematically normalize chemical compound names. Matching of synonymous names is achieved by comparison of the normalized name forms. It is capable of normalizing a given name of a chemical compound and matching it against names in (bio-)chemical databases (e.g. SABIO-RK, ChEBI or PubChem), even when there is no exact name-to-name-match. The tool is also able to match a complete list of compound names against these databases which makes it useful for the automatic annotation of chemical data.This normalization and matching of various synonyms of a chemical compound constitutes a platform for the unambiguous identification of compounds described in the literature or in databases.
Towards an Ontological Representation of Resistance: The Case of MRSa
Authors: Goldfain Albert , Cowell Lindsay , Smith Barry
Published: October 2010

This paper addresses a family of issues surrounding the biological phenomenon of resistance and its representation in realist ontologies. Resistance terms from various existing ontologies are examined and found to be either overly narrow, inconsistent, orotherwise problematic. We propose a more coherent ontological representation using the antibiotic resistance in Methicillin-Resistant Staphylococcus aureus (MRSa) as a case study.
Sex Hormones in Postmenopausal Women Receiving Low‐Dose Hormone Therapy: The Effect of BMI
Authors: Lambrinoudaki Irene , Armeni Eleni , Rizos Demetrios , Deligeoroglou Eythimios , Kofinakos Panagiotis , Kaparos George , Alexandrou Andreas , Creatsa Maria , Logothetis Emmanuel , Kouskouni Evangelia
Published: October 2010

The aim of our study was to evaluate the effect of BMI on the change in circulating sex hormone in postmenopausal women during 6 months of oral continuous combined low‐dose hormone therapy (HT). Fifty postmenopausal women were allocated to receive daily one tablet containing combination of 17β‐estradiol (1 mg)/norethindrone acetate (0.5 mg) for 6 months. Serum levels of follicle‐stimulating hormone (FSH), estradiol, total testosterone, sex hormone‐binding globulin (SHBG), free androgen index (FAI), free estrogen index (FEI), Δ4‐androstendione (Δ4A), and dehydroepiandrosterone sulfate were assessed at baseline and at the end of 6 months. Mean absolute values and percent changes from baseline were compared between lean and overweight women. Mean FSH decreased and mean 17β‐estradiol increased significantly in both groups (FSH lean: 82.3 ± 26.7 decreased to 45.0 ± 17.0 mIU/ml, P = 0.0001; FSH overweight: 85.5 ± 22.1 decreased to 52.3 ± 23.8 mIU/ml, P = 0.003; P between groups = 0.661; E2 lean: 23.24 ± 12.55 increased to 53.62 ± 28.29 pg/ml, P = 0.006; E2 overweight: 24.17 ± 10.88 increased to 68.36 ± 53.99 pg/ml, P = 0.0001; P between groups = 0.619). Lean individuals had statistically significant higher increments of FAI and specifically FEI compared to overweight (FEI lean; 0.14 ± 0.09 increased to 0.29 ± 0.14, P = 0.009; overweight 0.23 ± 0.18 increased to 0.52 ± 0.40, P = 0.126; P between groups = 0.034). Although BMI does not affect total 17β‐estradiol changes, free sex steroid concentrations increase more steeply in lean compared to overweight women receiving oral low‐dose HT.
F2‐Isoprostanes and Adiposity in Older Adults
Authors: Kanaya Alka M. , Wassel Christina L. , Stoddard Pamela J. , Harris Tamara B. , Cummings Steven R. , Kritchevsky Stephen B. , Goodpaster Bret H. , Green Christie , Satterfield Suzanne , Gross Myron D. ,   For the Health ABC Study
Published: October 2010

We examined whether a systemic marker of oxidative stress, F2‐isoprostanes (F2‐IPs), was associated with total and regional adiposity, adipocytokines, and change in adiposity. Using data from 726 participants enrolled in the Health, Aging, and Body Composition (Health ABC) study, F2‐IPs and adipocytokines were measured from baseline plasma samples. Total adiposity was measured by whole‐body dual‐energy X‐ray absorptiometry and regional adiposity by abdominal and thigh computed tomography scans at baseline and 5‐year follow‐up. ANOVA models were estimated to examine associations between F2‐IP tertiles and baseline adiposity and changes in body composition. Median F2‐IPs was 54.3 pg/ml; women had significantly higher levels than men (61.5 vs. 48.9 pg/ml, P < 0.001). F2‐IPs were associated with higher levels of adiponectin, leptin, and tumor necrosis factor‐α (TNF‐α). Positive associations were found between F2‐IPs and all measures of total and regional adiposity among women. In linear regression models, adipocytokines mediated associations among women. Over 5 years of follow‐up, women in the highest vs. lowest F2‐IP tertile exhibited significant loss of weight (lowest tertile: −1.1 kg, highest tertile: −2.7 kg, P < 0.05). In conclusion, F2‐IPs were associated with measures of total and regional adiposity in women alone and these associations were partially explained by adipocytokines. F2‐IPs predicted loss of total adiposity over time among women.
Duodenum Electrical Stimulation Delays Gastric Emptying, Reduces Food Intake and Accelerates Small Bowel Transit in Pigs
Authors: Xu Xiaohong , Lei Yong , Chen Jiande D.Z.
Published: October 2010

Duodenum electrical stimulation (DES) has been shown to delay gastric emptying and reduce food intake in dogs. The aim of this study was to investigate the effects of DES on gastric emptying, small bowel transit and food intake in pigs, a large animal model of obesity. The study consisted of three experiments (gastric emptying, small bowel transit, and food intake) in pigs implanted with internal duodenal electrodes for DES and one or two duodenal cannulas for gastric emptying and small bowel transit. We found that (i) gastric emptying was dose‐dependently delayed by DES of different stimulation parameters; (ii) small bowel transit was significantly accelerated with continuous DES in proximal intestine but not with intermittent DES; (iii) DES significantly reduced body weight gain with 100% duty cycle (DC), but not with DES with 40% DC. A marginal difference was noted in food intake among 100% DC session, 40% DC session, and control session. DES with long pulses energy‐dependently inhibits gastric emptying in pigs. DES with appropriate parameters accelerates proximal small bowel transit in pigs. DES reduces body weight gain in obese pigs, and this therapeutic effect on obesity is mediated by inhibiting gastric emptying and food intake, and may also possibly by accelerating intestinal transit. DES may have a potential application to treat patients with obesity.
The Relationship of Waist Circumference and BMI to Visceral, Subcutaneous, and Total Body Fat: Sex and Race Differences
Authors: Camhi Sarah M. , Bray George A. , Bouchard Claude , Greenway Frank L. , Johnson William D. , Newton Robert L. , Ravussin Eric , Ryan Donna H. , Smith Steven R. , Katzmarzyk Peter T.
Published: October 2010

The purpose of this study was to examine sex and race differences in the relationship between anthropometric measurements and adiposity in white and African‐American (AA) adults. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas were measured with computed tomography (CT). Fat mass (FM) was measured with dual‐energy‐X‐ray absorptiometry (DXA). Correlation coefficients were used to assess the relationship of waist circumference (WC) and BMI to VAT, SAT, and FM within sex‐by‐race groups. General linear models were used to compare relationships between WC or BMI, and adiposity across sex and race, within age groups (18–39 and 40–64 years). The sample included 1,667 adults (men: 489 white; 120 AA; women: 666 white, 392 AA). WC and BMI correlations were highest for FM and SAT compared to VAT. Women had higher FM levels than men regardless of WC, but the sex difference in FM was attenuated in younger AA adults with a high BMI. For a given level of WC or BMI, women had higher levels of SAT than men; however, significant interactions indicated that the relationship was not consistent across all levels of BMI and WC. Sex and race differences in VAT varied significantly with WC and BMI. In general, white adults had higher levels of VAT than AA adults at higher levels of BMI and WC. Sex differences, and in some instances race differences, in the relationships between anthropometry and fat‐specific depots demonstrate that these characteristics need to be considered when predicting adiposity from WC or BMI.
Sugar Content of Popular Sweetened Beverages Based on Objective Laboratory Analysis: Focus on Fructose Content
Authors: Ventura Emily E. , Davis Jaimie N. , Goran Michael I.
Published: October 2010

The consumption of fructose, largely in the form of high fructose corn syrup (HFCS), has risen over the past several decades and is thought to contribute negatively to metabolic health. However, the fructose content of foods and beverages produced with HFCS is not disclosed and estimates of fructose content are based on the common assumption that the HFCS used contains 55% fructose. The objective of this study was to conduct an objective laboratory analysis of the sugar content and composition in popular sugar‐sweetened beverages with a particular focus on fructose content. Twenty‐three sugar‐sweetened beverages along with four standard solutions were analyzed for sugar profiles using high‐performance liquid chromatography (HPLC) in an independent, certified laboratory. Total sugar content was calculated as well as percent fructose in the beverages that use HFCS as the sole source of fructose. Results showed that the total sugar content of the beverages ranged from 85 to 128% of what was listed on the food label. The mean fructose content in the HFCS used was 59% (range 47–65%) and several major brands appear to be produced with HFCS that is 65% fructose. Finally, the sugar profile analyses detected forms of sugar that were inconsistent with what was listed on the food labels. This analysis revealed significant deviations in sugar amount and composition relative to disclosures from producers. In addition, the tendency for use of HFCS that is higher in fructose could be contributing to higher fructose consumption than would otherwise be assumed.
Comprehensive Human Adipose Tissue mRNA and MicroRNA Endogenous Control Selection for Quantitative Real‐Time‐PCR Normalization
Authors: Neville Matt J. , Collins Jenny M. , Gloyn Anna L. , McCarthy Mark I. , Karpe Fredrik
Published: October 2010

The accurate quantification of cellular and tissue mRNA and microRNA content is reliant upon the selection of stable endogenous control transcripts for normalizing quantitative real‐time‐PCR (qRT‐PCR) data. Using the combination of unbiased and informed approaches and a wide range of human adipose tissues and cells, we sought to identify invariant control transcripts for mRNA and microRNA. A total of 26 mRNA transcript candidates were selected from the literature. MicroRNA candidates were selected from a microRNA‐microarray (Agilent, n = 22 tissues), and together with candidates from the literature resulted in 14 different microRNAs. The variability of these mRNA and microRNA transcripts were then tested in a large (n = 180) collection of a variety of human adipose tissues and cell samples. Phosphoglycerate kinase‐1 (PGK1) and peptidylprolyl isomerase A (PPIA) were identified as the most stable mRNAs across all tissues and panels. MiR‐103 was overall the most stable microRNA transcript across all biological backgrounds. Several proposed and commonly used normalization transcripts were found to be highly variable. We then tested the effect on expression of two established adipocyte‐related transcripts (fatty acid binding protein 4 (FABP4) and microRNA‐145 (miR‐145)), either normalized to the optimal or a commonly used controls transcript. This test clearly indicated that spurious results could arise from using less stable control transcripts for mRNA and microRNA qRT‐PCR.
Phosphate toxicity: new insights into an old problem
Authors: Razzaque M. Shawkat
Published: October 2010

Phosphorus is an essential nutrient required for critical biological reactions that maintain the normal homoeostatic control of the cell. This element is an important component of different cellular structures, including nucleic acids and cell membranes. Adequate phosphorus balance is vital for maintaining basic cellular functions, ranging from energy metabolism to cell signalling. In addition, many intracellular pathways utilize phosphate ions for important cellular reactions; therefore, homoeostatic control of phosphate is one of the most delicate biological regulations. Impaired phosphorus balance can affect the functionality of almost every human system, including musculoskeletal and cardiovascular systems, ultimately leading to an increase in morbidity and mortality of the affected patients. Human and experimental studies have found that delicate balance among circulating factors, like vitamin D, PTH (parathyroid hormone) and FGF23 (fibroblast growth factor 23), are essential for regulation of physiological phosphate balance. Dysregulation of these factors, either alone or in combination, can induce phosphorus imbalance. Recent studies have shown that suppression of the FGF23–klotho system can lead to hyperphosphataemia with extensive tissue damage caused by phosphate toxicity. The cause and consequences of phosphate toxicity will be briefly summarized in the present review.
Development of neutron spectrometer toward deuterium plasma diagnostics in LHD
Authors: Tomita H. , Iwai H. , Iguchi T. , Isobe M. , Kawarabayashi J. , Konno C.
Published: October 2010

Neutron spectrometer based on coincident counting of associated particles has been developed for deuterium plasma diagnostics on Large Helical Device (LHD) at the National Institute for Fusion Science. Efficient detection of 2.5 MeV neutron with high energy resolution would be achievable by coincident detection of a scattered neutron and a recoiled proton associated with an elastic scattering of incident neutron in a plastic scintillator as a radiator. The calculated neutron spectra from deuterium plasma heated by neutral beam injection indicate that the energy resolution of better than 7% is required for the spectrometer to evaluate energetic deuterium confinement. By using a prototype of the proposed spectrometer, the energy resolution of 6.3% and the detection efficiency of 3.3×10−7 count/neutron were experimentally demonstrated for 2.5 MeV monoenergetic neutron, respectively.
Competition for popularity in bipartite networks
Authors: Beguerisse Díaz Mariano , Porter Mason A. , Onnela Jukka-Pekka
Published: October 2010

We present a dynamical model for rewiring and attachment in bipartite networks. Edges are placed between nodes that belong to catalogs that can either be fixed in size or growing in size. The model is motivated by an empirical study of data from the video rental service Netflix, which invites its users to give ratings to the videos available in its catalog. We find that the distribution of the number of ratings given by users and that of the number of ratings received by videos both follow a power law with an exponential cutoff. We also examine the activity patterns of Netflix users and find bursts of intense video-rating activity followed by long periods of inactivity. We derive ordinary differential equations to model the acquisition of edges by the nodes over time and obtain the corresponding time-dependent degree distributions. We then compare our results with the Netflix data and find good agreement. We conclude with a discussion of how catalog models can be used to study systems in which agents are forced to choose, rate, or prioritize their interactions from a large set of options.
Mechanisms leading to fast relaxation of liquid crystal cells aligned with conductive polymers
Authors: Nicastro Gaetano , Scaramuzza Nicola , Bartolino Roberto , Alexe-Ionescu Anca-Luiza , Ionescu Andrei Th.
Published: October 2010

Using nematic liquid crystal cells aligned by conductive polymers, like polyaniline or doped polypyrrole, a very fast electro-optic response is observed. We show that when a switch that interrupts the voltage across the cell is placed between the cell and the ground, the largest voltage drop is on the switch in its open position. The voltage distribution among the nematic cell and the switch is evaluated. The role played in this very fast electro-optic response of the ionic charges built on the interfaces together with the redox processes among the free charges in the polymer-liquid crystal interface is also described. For an asymmetric cell (only one side covered with a conductive polymer) a rectifying effect appears. In this case a circuital model is used to mimic the steplike behavior of the transmitted light during the relaxation of the system.
Poloidal beam emission spectroscopy system for the measurement of density fluctuations in Large Helical Device
Authors: Oishi T. , Kado S. , Ida K. , Yoshinuma M. , Nakano H. , Yamazaki K.
Published: October 2010

A system of beam emission spectroscopy (BES) for density fluctuation measurements having the sightlines passing through the plasma in the poloidal direction was developed in the Large Helical Device (LHD). Even though the angle between the beam and the sightline is slightly larger than a right angle, Doppler-shifted beam emission can be distinguished from background emission because of the high energy (120–170 keV) of the neutral beam for heating with negative ion sources. Spatial resolution is about 0.1–0.2 in the normalized radius. Compared with the prototype BES system with toroidal sightlines, the BES system with poloidal sightlines showed improved spatial resolution.
Grating spectrometer system for beam emission spectroscopy diagnostics using high-energy negative-ion-based neutral beam injection on LHD
Authors: Kado S. , Oishi T. , Yoshinuma M. , Ida K.
Published: October 2010

A beam emission spectroscopy (BES) system was developed for density gradient and fluctuation diagnostics in the Large Helical Device (LHD). In order to cover the large Doppler shift of the Hα beam emission because of the high-energy negative-ion-based neutral beam atom (acceleration voltage Vacc=90–170 kV) and the large motional Stark splitting due to the large v×B field (magnetic field B=3.0 T), a grating spectrometer was used instead of a conventional interference filter system. The reciprocal linear dispersion is about 2 nm/mm, which is sufficient to cover the motional Stark effect spectra using an optical fiber with a diameter of 1 mm.
Note: Fully integrated time-to-amplitude converter in Si–Ge technology
Authors: Crotti M. , Rech I. , Ghioni M.
Published: October 2010

Over the past years an always growing interest has arisen about the measurement technique of time-correlated single photon counting TCSPC), since it allows the analysis of extremely fast and weak light waveforms with a picoseconds resolution. Consequently, many applications exploiting TCSPC have been developed in several fields such as medicine and chemistry. Moreover, the development of multianode PMT and of single photon avalanche diode arrays led to the realization of acquisition systems with several parallel channels to employ the TCSPC technique in even more applications. Since TCSPC basically consists of the measurement of the arrival time of a photon, the most important part of an acquisition chain is the time measurement block, which must have high resolution and low differential nonlinearity, and in order to realize multidimensional systems, it has to be integrated to reduce both cost and area. In this paper we present a fully integrated time-to-amplitude converter, built in 0.35 μm Si–Ge technology, characterized by a good time resolution (60 ps), low differential nonlinearity (better than 3% peak to peak), high counting rate (16 MHz), low and constant power dissipation (40 mW), and low area occupation (1.38×1.28 mm2).
NMR probe for pressure-jump experiments up to 250 bars and 3 ms jump time
Authors: Heuert U. , Krumova M. , Hempel G. , Schiewek M. , Blume A.
Published: October 2010

We describe the design and performance of a pressure-jump instrument for time-resolved NMR experiments. Initial pressure of up to 250 bars can be produced by means of a HPLC pump and distilled water as a pressure-transmitting liquid. Fast pressure release at a time resolution of 3 ms is achieved using a fast acting valve driven by a piezostack close to the sample chamber. The pressure-jump cell is placed together with two valves in an especially designed NMR probe, which can be used in standard spectrometers with wide-bore magnets. All functions of the instrument are personal computer controlled. The equipment is designed for investigations on systems of biological interest, especially lipid-water dispersions. A theoretical consideration implies that probably the limited speed of valve opening determines the lower boundary of the jump time. The performance is illustrated by time-resolved NMR spectra across the phase transition of a phospholipid-water dispersion after a pressure jump from 100 bars to atmospheric pressure.
A two-temperature model of radiation damage in α-quartz
Authors: Phillips Carolyn L. , Magyar Rudolph J. , Crozier Paul S.
Published: October 2010

Two-temperature models are used to represent the physics of the interaction between atoms and electrons during thermal transients such as radiation damage, laser heating, and cascade simulations. We introduce a two-temperature model applied to an insulator, α-quartz, to model heat deposition in a SiO2 lattice. Our model of the SiO2 electronic subsystem is based on quantum simulations of the electronic response in a SiO2 repeat cell. We observe how the parametrization of the electronic subsystem impacts the degree of permanent amorphization of the lattice, especially compared to a metallic electronic subsystem. The parametrization of the insulator electronic subsystem has a significant effect on the amount of residual defects in the crystal after 10 ps. While recognizing that more development in the application of two-temperature models to insulators is needed, we argue that the inclusion of a simple electronic subsystem substantially improves the realism of such radiation damage simulations.
Aggregate fractal dimensions and thermal conduction in nanofluids
Authors: Gharagozloo Patricia E. , Goodson Kenneth E.
Published: October 2010

The mechanism producing enhanced thermal conductivities of nanofluids has been the subject of much debate. The formation of aggregates allowing for percolation paths within the fluid has shown the most promise. This work studies the aggregate formation of a nanofluid and compares the results to earlier thermal conductivity measurements and Monte Carlo simulation results. Static light scattering is employed to measure the fractal dimension of aggregates formed in the nanofluid over time at various temperatures and concentrations. As expected, aggregates form more quickly at higher concentrations and temperatures, which explains the increased enhancement with temperature reported by other research groups. The permanent aggregates in the nanofluid are found to have a fractal dimension of 2.4 and the aggregate formations that grow over time are found to have a fractal dimension of 1.8, which is consistent with diffusion limited aggregation. Predictions indicate that as aggregates grow the viscosity increases at a faster rate than thermal conductivity making the highly aggregated nanofluids unfavorable, especially at the low fractal dimension of 1.8.