bluuebunny/crossref_metadata_2025 huggingface dataset:
Hierarchical structure in polymer‐based drug delivery systems as probed by calorimetric measurements
Authors: Valot Pascale , Sintes‐Zydowicz Nathalie , Nedelec Jean‐Marie , Baba Mohamed
Published: August 2010

Thermoporosimetry (TPM), a differential scanning calorimetry technique that relies on the shift of transition temperatures caused by the confinement of liquids, was applied to elucidate the complex morphology of drug‐loaded polymeric microcapsules prepared by the emulsion solvent evaporation method. For the very first time, TPM has been applied simultaneously with two liquids as structural probes. It was found that Miglyol, which dissolves the selected drug (Ibuprofen), is confined inside vesicles having a mean radius of 26.3 nm, whereas water, which is the continuous phase, is trapped inside a swollen polymeric network of Eudragit with an average mesh radius of 1.7 nm. A proposed hierarchical structure is given, which predicts that Eudragit microcapsules are formed from a collection of inert oil vesicles partitioned by polymeric Eudragit membranes swollen by water. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1939–1945, 2010
Crystallization kinetics of polymer brushes with poly(ethylene oxide) side chains
Authors: Zheng Ying , Bruening Merlin L. , Baker Gregory L.
Published: August 2010

Isothermal crystallization rates of semicrystalline poly(methoxypoly(ethylene glycol) methacrylate) brushes on gold‐coated substrates were measured by polarized optical microscopy. Growth rates for crystal radii, which were essentially constant for each film, initially increased with film thickness and then leveled off for film thicknesses >300 nm. Avrami–Evans theory suggests that the spherulites exhibit one‐dimensional growth with heterogeneous nucleation. Compared with physisorbed analogs, polymer brushes crystallized slower due to the restriction of chain mobility. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1955–1959, 2010
Near‐infrared spectroscopy for the quantitative determination of mass transfer and water absorption kinetics by a polymer solution
Authors: Pochat‐Bohatier Céline , Werapun Warit , Bouyer Denis , Chinpa Watchanida , Deratani André
Published: August 2010

This article reports a new method to quantify the water absorption kinetics and the mass transfer in a polymer solution by using near‐infrared (NIR) spectroscopy and partial least‐squares (PLS) models, while it is exposed to a humid atmosphere. Polymer solutions used in this study were made with highly polar solvents exhibiting both a high affinity for water and a low volatility such as dimethylformamide, dimethylacetamide, and N‐methylpyrrolidone. Poly(ethersulfone) and poly(etherimide) were chosen as polymer models as the method could provide useful information for coating process and membrane fabrication monitoring. Whereas gravimetric kinetics yield data on the overall mass transfer, including both water absorption and solvent evaporation, in situ analyses using NIR can quantify separately the solvent and nonsolvent concentration change in the polymer solution. Quantitative models were developed using PLS regression to predict the local water, polymer, and solvent weight fractions in the polymer solution. The method was proved to be suitable for the different studied systems and allowed to infer mass transfers until the onset of the phase separation process. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1960–1969, 2010
Protein resistance of polyurethane with hydrophilic and hydrophobic soft segments
Authors: Ma Chunfeng , Zhou Guoying , Zhang Guangzhao
Published: August 2010

Polyurethane (PU) containing poly(propylene glycol) (PPG) or poly(tetramethylene oxide) (PTMG) soft segments have been prepared by two‐step condensation polymerization. The former (PPG‐PU) with a lower critical solution temperature (LCST) at ∼21 °C can change from hydrophilic to hydrophobic, whereas the latter (PTMG‐PU) is hydrophobic at a temperature above 0 °C. The adsorption of fibrinogen, bovine serum albumin, or lysozyme on such a PU surface in aqueous solution has been investigated by use of quartz crystal microbalance with dissipation (QCM‐D) and surface plasmon resonance (SPR) in real time. PPG‐PU surface exhibits protein resistance at a temperature below the LCST of PPG, but it significantly adsorbs proteins at a temperature above the LCST. On the other hand, the hydrophobic PTMG‐PU surface adsorb the proteins at any temperatures investigated, in contrast with the hydrated poly(ethylene glycol) exhibiting excellent protein resistance. The hydration and dehydration of the polymers at different temperatures were confirmed by Raman spectroscopy. Our study demonstrates that the protein resistance of polymers is determined by their hydration. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1987–1993, 2010
New simple method of measuring the surface glass transition temperature of polymers
Authors: Boiko Yuri M.
Published: August 2010

A lap‐shear joint mechanical testing method has been probed to measure the surface glass transition temperature (T) of the thick bulk films of high‐molecular‐weight polymers. As T, the temperature transition “occurrence of autoadhesion–nonoccurrence of autoadhesion” has been proposed. The influence of chain flexibility, of molecular architecture, of polymer morphology, and of chain ends concentration on the T has been investigated. The correlation between the reduction in T with respect to the glass transition temperature of the bulk (T) and the intensity of the intermolecular interaction in the polymer bulk in amorphous polymers has been found. The effect of surface roughness on T has been discussed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 2012–2021, 2010
Neutralization phenomena observed with secondary ions originating from inner‐shell excitation
Authors: Wittmaack Klaus
Published: August 2010

The observation of comparatively high yields of low‐energy secondary ions, ejected from clean ion‐bombarded solids, has been a long‐standing miracle. The measured velocity dependence of the ionization probability is at variance with the predicted exponential velocity dependence. It has been proposed that the recorded high yields are due to electronic excitations initiated by the collision cascade. Here, the issue is addressed by exploring energy spectra of ions generated by inner shell electron promotion during energetic collisions. Using new experimental results and literature data, ionization probabilities were determined using two different approaches. The evaluated data suggest that doubly charged ions of Mg, Al and Si (and possibly, Ca) can escape neutralization, presumably as a consequence of Auger deexcitation taking place at sufficiently large distances from the surface. The ion fractions for Sc, Ti, V and Cr are in accordance with an exponential velocity dependence at energies > 300 eV, but approach a constant level at low energies. Given the fact that the electronic‐excitation model does not apply in the case of ionization by electron promotion, it is suggested that the unusually high ionization probabilities observed at low energies are due to suppressed neutralization. The idea is that in a small fraction of impact events the collision cascade may generate a very high perturbation of the surface (‘dynamic randomization’) so that a well‐defined band structure may not exist, locally and for a short period of time. In these rare cases, the conduction electrons required for neutralization are not available. Copyright © 2010 John Wiley & Sons, Ltd.
Loss of Bright/ARID3a Function Promotes Developmental Plasticity
Authors: An Guangyu , Miner Cathrine A. , Nixon Jamee C. , Kincade Paul W. , Bryant James , Tucker Philip W. , Webb Carol F.
Published: August 2010

B-cell regulator of immunoglobulin heavy chain transcription (Bright)/ARID3a, an A+T-rich interaction domain protein, was originally discovered in B lymphocyte lineage cells. However, expression patterns and high lethality levels in knockout mice suggested that it had additional functions. Three independent lines of evidence show that functional inhibition of Bright results in increased developmental plasticity. Bright-deficient cells from two mouse models expressed a number of pluripotency-associated gene products, expanded indefinitely, and spontaneously differentiated into cells of multiple lineages. Furthermore, direct knockdown of human Bright resulted in colonies capable of expressing multiple lineage markers. These data suggest that repression of this single molecule confers adult somatic cells with new developmental options.
Simultaneous LC‐MS/MS determination of phenylbutyrate, phenylacetate benzoate and their corresponding metabolites phenylacetylglutamine and hippurate in blood and urine
Authors: Laryea Maurice D. , Herebian Diran , Meissner Thomas , Mayatepek Ertan
Published: August 2010

Inborn errors of urea metabolism result in hyperammonemia. Treatment of urea cycle disorders can effectively lower plasma ammonium levels and results in survival in the majority of patients. Available medications for treating urea cycle disorders include sodium benzoate (BA), sodium phenylacetate (PAA), and sodium phenylbutyrate (PBA) and are given to provide alternate routes for disposition of waste nitrogen excretion. In this study, we develop and validate a liquid chromatography tandem mass spectrometry (LC‐MS/MS) method for simultaneous determination of benzoic acid, phenylacetic acid, phenylbutyric acid, phenylacetylglutamine, and hippuric acid in plasma and urine from children with inborn errors of urea synthesis. Plasma extracts and diluted urine samples were injected on a reverse‐phase column and identified and quantified by selected reaction monitoring (SRM) in negative ion mode. Deuterated analogues served as internal standards. Analysis time was 7 min. Assay precision, accuracy, and linearity and sample stability were determined using enriched samples. Quantification limits of the method were 100 ng/ml (0.3–0.8 μmol/L) for all analytes, and recoveries were >90%. Inter‐ and intraday relative standard deviations were <10%. Our newly developed LC‐MS/MS represents a robust, sensitive, and rapid method that allows simultaneous determination of the five compounds in plasma and urine.
Isolation of a point‐mutated p47 lacking binding affinity to p97ATPase
Authors: Kaneko Yayoi , Tamura Kaori , Totsukawa Go , Kondo Hisao
Published: August 2010

MINT‐7987326: p97 (uniprotkb:P46462) binds (MI:0407) to p37 (uniprotkb:Q0KL01) by pull down (MI:0096)
Molecular characterization of β1,4‐galactosyltransferase 7 genetic mutations linked to the progeroid form of Ehlers–Danlos syndrome (EDS)
Authors: Bui Catherine , Talhaoui Ibtissam , Chabel Matthieu , Mulliert Guillermo , Coughtrie Michael W.H. , Ouzzine Mohamed , Fournel-Gigleux Sylvie
Published: August 2010

β1,4‐Galactosyltransferase 7 (β4GalT7) is a key enzyme initiating glycosaminoglycan (GAG) synthesis. Based on in vitro and ex vivo kinetics studies and structure‐based modelling, we molecularly characterized β4GalT7 mutants linked to the progeroid form of Ehlers–Danlos syndrome (EDS), a severe connective tissue disorder. Our results revealed that loss of activity upon L206P substitution due to altered protein folding is the primary cause for the GAG synthesis defect in patients carrying the compound A186D and L206P mutations. We showed that R270C substitution strongly reduced β4GalT7 affinity towards xyloside acceptor, thus affecting GAG chains formation. This study establishes the molecular basis for β4GalT7 defects associated with altered GAG synthesis in EDS.
The correlation coefficient of GC content of the genome‐wide genes is positively correlated with animal evolutionary relationships
Authors: Du Hongli , Hu Haofu , Meng Yuhuan , Zheng Weihao , Ling Fei , Wang Jufang , Zhang Xiquan , Nie Qinghua , Wang Xiaoning
Published: August 2010

In this study, we present a new method for evaluating animal evolutionary relationships. We used the GC% levels of genome‐wide genes to determine the correlation between the GC% content and evolutionary relationship. The correlation coefficients of the GC% content of the orthologous genes of the paired animal species were calculated for a total of 21 species, and the evolutionary branching dates of these 21 species were derived from fossil records. The correlation coefficient of the GC% content of the orthologous genes of the species pair under study served as an indicator of their evolutionary relationship. Moreover, there was a decreasing linear relationship between the correlation coefficient and evolutionary branching date (R
2
= 0.930).
Changes in gene expression after phencyclidine administration in developing rats: a potential animal model for schizophrenia
Authors: Liu F. , Zou X. , Sadovova N. , Zhang X. , Shi L. , Guo L. , Qian F. , Wen Z. , Patterson T.A. , Hanig J.P. , Paule M.G. , Slikker W. , Wang C.
Published: August 2010

Repeated administration of phencyclidine (PCP), anN‐methyl‐d‐aspartate (NMDA) receptor antagonist, during development, may result in neuronal damage that leads to behavioral deficits in adulthood. The present study examined the potential neurotoxic effects of PCP exposure (10 mg/kg) in rats on postnatal days (PNDs) 7, 9 and 11 and the possible underlying mechanism(s) for neurotoxicity. Brain tissue was harvested for RNA extraction and morphological assessments. RNA was collected from the frontal cortex for DNA microarray analysis and quantitative RT‐PCR. Gene expression profiling was determined using Illumina Rat Ref‐12 Expression BeadChips containing 22,226 probes. Based on criteria of a fold‐change greater than 1.4 and aP‐value less than 0.05, 19 genes including NMDAR1 (N‐methyl‐d‐aspartate receptor) and four pro‐apoptotic genes were up‐regulated, and 25 genes including four anti‐apoptotic genes were down‐regulated, in the PCP‐treated group. In addition, the schizophrenia‐relevant genes, Bdnf (Brain‐derived neurotrophic factor) and Bhlhb2 (basic helix‐loop‐helix domain containing, class B, 2), were significantly different between the PCP and the control groups. Quantitative RT‐PCR confirmed the microarray results. Elevated neuronal cell death was further confirmed using Fluoro‐Jade C staining. These findings support the hypothesis that neurodegeneration caused by PCP occurs, at least in part, through the up‐regulation of NMDA receptors, which makes neurons possessing these receptors more vulnerable to endogenous glutamate. The changes in schizophrenia‐relevant genes after repeated PCP exposure during development may provide important information concerning the validation of an animal model for this disorder.
Automation of Human IgG, Glucose, Lactate, and Oxygen Assays on Biomek NXP Span-8 Automation Workstation and PARADIGM Detection Platform
Authors: Liu Li , Zhang Ruth , Pajak Laura
Published: August 2010

When optimizing cell culture media for therapeutic antibody production cell lines, it is very important to monitor parameters such as IgG concentration, glucose and lactate levels, and oxygen consumption in culture medium in an automated high-throughput manner to ensure the desirable growth conditions. In this report, assays for measuring human IgG, glucose, and lactate concentrations, and oxygen consumption were automated using the Biomek NXP Span-8 workstation, and analyzed on the PARADIGM Detection Platform. The human-IgG homogeneous time-resolved fluorescence (HTRF) (All trademarks are the property of their respective owners.) assay from Cisbio Inc. (Cisbio US, Bedford, MA) was automated in a 384-well plate format and detected on the PARADIGM with a HTRF Detection Cartridge. Glucose and lactate assays were automated in a 96-well plate format and detected on the PARADIGM with a Fluorescence Intensity Cartridge. Oxygen consumption was determined by the 96-well calibration-free OxoPlate (All trademarks are the property of their respective owners.) (PreSens Inc., PreSens - Precision Sensing GmbH, Regensburg, Germany) and detected by the PARADIGM with a MultiMode Detection Cartridge.

The data for human IgG, glucose, lactate, and oxygen consumption assays automated on the Biomek NXP demonstrate the accuracy and precision obtained using the automated protocols on the PARADIGM Detection Platform, with the user-friendly and assay-specific cartridges for easy, quick, and accurate detection. Using this as a model, one would be able to adapt these approaches to high-throughput media optimization and cell monitoring.
Web‐based application to project the burden of Alzheimer's disease
Authors: Colantuoni Elizabeth , Surplus Greg , Hackman Andre , Arrighi H. Michael , Brookmeyer Ron
Published: August 2010

Background

Health care planning and research would benefit from tools that enable researchers to project the future burden of Alzheimer's disease (AD) and evaluate the effect of potential interventions.

Methods

We created a web‐based application of the AD prevalence model developed by Brookmeyer et al (Am J Public Health 1998;88:1337–42; Alzheimers Dement 2007;3:186–91). The user defines the disease parameters and any interventions that may either reduce risk or slow disease progression. We expanded the parameters to include the cost and weights for disability‐adjusted life years.

Application

The secure, web‐based application generates detailed AD projections for each calendar year to 2050, and allows users to create personal accounts for them to save, retrieve, and modify the input parameters. The flexibility of the application is illustrated with a forecast for the state of Maryland, USA.

Conclusions

The application generates AD burden projections, costs, and disability‐adjusted life years, along with changes associated with potential interventions.
Aristotle
Authors: Lear Jonathan
Published: August 2010

This is a 1988 philosophical introduction to Aristotle, and Professor Lear starts where Aristotle himself starts. The first sentence of the Metaphysics states that all human beings by their nature desire to know. But what is it for us to be animated by this desire in this world? What is it for a creature to have a nature; what is our human nature; what must the world be like to be intelligible; and what must we be like to understand it systematically? Through a consideration of these questions Professor Lear introduces us to the essence of Aristotle's philosophy and guides us through the central Aristotelian texts - selected from the Physics, Metaphysics, Ethics, Politics and from the biological and logical works. The book is written in a direct, lucid style which engages the reader with the themes in an active, participatory manner.
English Words
Authors: Stockwell Robert , Minkova Donka
Published: August 2010

English Words: History and Structure is concerned primarily with the learned vocabulary of English, the words borrowed from the classical languages. It surveys the historical events that define the layers of vocabulary in English, introduces some of the basic principles of linguistic analysis, and is a helpful manual for vocabulary discernment and enrichment. Exercises accompanying each chapter and further readings on recent loans and the legal and medical vocabulary of English will be available online in the near future.
• Introduces students to some basic linguistic terms needed for the discussion of phonological and morphological changes accompanying word formation
• Designed to lead students to a finer appreciation of their language and greater ability to recognize relationships between words and discriminate between meanings
• An informative appendix discusses the history and usefulness of the best known British and American dictionaries
• Online readings and exercises to deepen and strengthen knowledge acquired in the classroom
The inhibitory effect of genistein on hepatic steatosis is linked to visceral adipocyte metabolism in mice with diet-induced non-alcoholic fatty liver disease
Authors: Kim Mi-Hyun , Kang Kyung-Sun , Lee Yeon-Sook
Published: August 2010

Non-alcoholic fatty liver disease (NAFLD) has been deeply associated with visceral adiposity, adipose tissue inflammation and a variety of adipocytokines. We reported previously that genistein inhibited NAFLD by enhancing fatty acid catabolism. However, this molecular approach focused on hepatic metabolism. Thus, we have attempted to determine whether this anti-steatotic effect of genistein is linked to visceral adipocyte metabolism. C57BL/6J mice were fed on normal-fat (NF) diet, high-fat (HF) diet and HF diet supplemented with genistein (1, 2 and 4 g/kg diet) for 12 weeks. Mice fed on the HF diet gained body weight, exhibited increased visceral fat mass and elevated levels of serum and liver lipids, and developed NAFLD, unlike what was observed in mice fed on the NF diet. However, genistein supplementation (2 and 4 g/kg diet) normalised these alternations. In the linear regression analysis, visceral fat (R0·77) and TNFα (R0·62) were strongly correlated with NAFLD among other NAFLD-related parameters. Genistein supplementation suppressed the hypertrophy of adipocytes via the up-regulation of genes involved in fatty acid β-oxidation, including PPARα, 5′-AMP-activated protein kinase and very long-chain acyl CoA dehydrogenase, as well as through the down-regulation of genes associated with adipogenesis or lipogenesis, including liver X receptor-α, sterol-regulatory element-binding protein-1c, PPARγ, retinoid X receptor-α and acetyl CoA carboxylase 2. Moreover, genistein supplementation augmented an anti-steatohepatitic adiponectin TNF and reduced a steatohepatitic TNFα. Collectively, these findings show that genistein may prevent NAFLD via the regulation of visceral adipocyte metabolism and adipocytokines.
Effect of dietary fibre mixture on growth and intestinal iron absorption in rats recovering from iron-deficiency anaemia
Authors: Koester Weber Thabata , de Cássia Freitas Karine , Amancio Olga Maria Silvério , Morais Mauro Batista de
Published: August 2010

There is concern regarding the possible negative effects of ingestion of dietary fibre on growth and intestinal Fe absorption in infants. The aim of the present study was to compare the effect of a fibre mixture on the growth and the intestinal absorption of Fe in rats with Fe-deficiency anaemia with that of a diet without fibres. Faecal weight and caecal pH were also evaluated. According to the Hb depletion–repletion model, twenty-two male weaned Wistar rats were fed the AIN93-G diet without Fe until Fe-deficiency anaemia was induced with Hb < 70 g/l. The anaemic rats were divided into two groups: (1) fibre mixture group – fed 100 g of fibre mixture/kg of diet (soya polysaccharide, inulin, resistant starch, Arabic gum, fructo-oligossaccharide and cellulose) (n 11); (2) control group – fed without fibres (n 11). All diets had 157 mg of ferric citrate (30 mg of elemental Fe) added to lead to recovery from anaemia. Fe intestinal absorption was measured by Hb repletion efficiency (HRE) and apparent Fe intestinal absorption. The HRE was 44·8 (sd 9·5) % in the fibre mixture group and 43·0 (sd 9·5) % in the control group (P = 0·664). The apparent Fe absorption was 46·2 (sd 16·5) and 47·2 (sd 10·2) % (P = 0·861) in the fibre mixture and control groups, respectively. The faecal weight median was 6·17 g in the fibre mixture group and 2·11 g in the control group (P < 0·001). The caecal pH was in the same order: 6·11 (sd 0·59) and 7·07 (sd 0·34) (P < 0·001). Both the groups consumed similar quantities of diet, and growth was similar in both the groups. The fibre mixture had no influence either on growth or on Fe intestinal absorption in rats recovering from anaemia. This mixture favoured an increase in faecal weight and a decrease in caecal pH.
Life around … : Staff’s Perceptions of Residents’ Adjustment into Long-Term Care
Authors: Wiersma Elaine C.
Published: August 2010

Le déménagement à un établissement de service de soins à long terme peut être particulière-ment traumatique pour de nouveaux résidents. Le personnel peut faciliter cette transition dans un certain nombre de façons. Cependant, les perceptions du personnel du processus de transition et les expériences des résidents joueront un rôle significatif en déterminant le type d’appui qui est donné aux résidents pendant cette transition. Le but de cette recherche était d’examiner les perceptions du personnel d’une personne venant à vivre dans un environnement de soins à long terme. Trois thèmes principaux ont émergé après l’analyse d’entrevues détaillées avec le personnel d’un service de soin à long terme qui englobaient les descriptions de la vie des résidents. Essentiellement, le personnel a décrit comment les résidents ont appris à vivre une vie autour de divers facteurs en trois catégories principaux: une vie autour des pertes, une vie autour de l’établissement résidentiel, et une vie autour du corps.
Hydraulic and chemical pulse tests in a shut‐in chamber imbedded in an argillaceous formation: Numerical and experimental approaches
Authors: Rousseau‐Gueutin P. , Gonçalvès J. , Cruchaudet M. , de Marsily G. , Violette S.
Published: August 2010

Hydraulic and chemical pulse tests were performed in four shut‐in chambers to obtain hydraulic and chemical parameters of the Callovo‐Oxfordian shale. The osmotic tests, i.e., chemical pulses, were carried out by exchange of the formation water for a different solution either more or less concentrated. Two sets of two osmotic tests were done in March and October 2006. These osmotic tests are superimposed on a purely hydraulic response because of the drilling of the well causing a pressure drop. The pressure records (hydraulic and osmotic responses) were interpreted using a 2‐D model to obtain the hydraulic and chemical parameters. The osmotic efficiency inferred for the Callovo‐Oxfordian shale is on the order of 0.012 for a concentration of 0.43 mol L−1 and 0.12 for a concentration of 0.086 mol L−1. These results suggest that the Callovo‐Oxfordian shale behaves as a weakly semipermeable membrane and only 0.1–0.15 MPa of the 0.2–0.5 MPa can be explained by these osmotic efficiency values.
Slow slip events in Mexico revised from the processing of 11 year GPS observations
Authors: Vergnolle M. , Walpersdorf A. , Kostoglodov V. , Tregoning P. , Santiago J. A. , Cotte N. , Franco S. I.
Published: August 2010

The world's largest observed Slow Slip Events (SSE) occurred in 2001–2002 and 2006 in the Guerrero subduction zone, Mexico. Using an improved GPS processing that accounts for time‐varying atmospheric phenomena as well as oceanic, atmospheric and hydrologic loading corrections, the 11 year GPS position time series in Guerrero show a noise reduction of ∼50% with respect to previous studies. Thanks to the improved position time series and, in particular, the simultaneous analysis of the three‐dimensional GPS observations, we can provide new information about SSEs in the studied area. First, we detect seven nonperiodic anomalous displacements with subcentimeter amplitude, but no quasi‐annual anomalies as proposed previously. The displacements seem to occur simultaneously with the observed peaks of non‐volcanic tremor activity in the area. Second, we refine the characteristics of the two major SSEs in terms of timing, duration, and cumulative displacements, and highlight the complex surface spatiotemporal evolution of the displacements during these SSEs. In particular, we observe a clear initiation phase for the 2006 SSE as well as ending phases for both large SSEs. The ending phase shows a strong deceleration of the anomalous displacements with respect to the main displacement phase already observed, for the 2001–2002 and 2006 SSEs. The duration of the SSEs increases by 30–40% including the initiation and ending phases. For the 2006 SSE, the main displacement phase also shows spatiotemporal complexity. Our results demonstrate the need for improved three‐dimensional GPS processing technique in order to undertake detailed studies of SSEs.
The Caribbean–South American plate boundary at 65°W: Results from wide‐angle seismic data
Authors: Bezada M. J. , Magnani M. B. , Zelt C. A. , Schmitz M. , Levander A.
Published: August 2010

We present the results of the analysis of new wide‐angle seismic data across the Caribbean–South American plate boundary in eastern Venezuela at about 65°W. The ∼500 km long profile crosses the boundary in one of the few regions dominated by extensional structures, as most of the southeastern Caribbean margin is characterized by the presence of fold and thrust belts. A combination of first‐arrival traveltime inversion and simultaneous inversion of PmP and Pn arrivals was used to develop a P wave velocity model of the crust and the uppermost mantle. At the main strike‐slip fault system, we image the Cariaco Trough, a major pull‐apart basin along the plate boundary. The crust under the Southern Caribbean Deformed Belt exhibits a thickness of ∼15 km, suggesting that the Caribbean Large Igneous Province extends to this part of the Caribbean plate. The velocity structures of basement highs and offshore sedimentary basins imaged by the profile are comparable to those of features found in other parts of the margin, suggesting similarities in their tectonic history. We do not image an abrupt change in Moho depth or velocity structure across the main strike‐slip system, as has been observed elsewhere along the margin. It is possible that a terrane of Caribbean island arc origin was accreted to South America at this site and was subsequently bisected by the strike‐slip fault system. The crust under the continental portion of the profile is thinner than observed elsewhere along the margin, possibly as a result of thinning during Jurassic rifting.
Light absorption properties and absorption budget of Southeast Pacific waters
Authors: Bricaud Annick , Babin Marcel , Claustre Hervé , Ras Joséphine , Tièche Fanny
Published: August 2010

Absorption coefficients of phytoplankton, nonalgal particles (NAPs), and colored dissolved organic matter (CDOM), and their relative contributions to total light absorption, are essential variables for bio‐optical and biogeochemical models. However, their actual variations in the open ocean remain poorly documented, particularly for clear waters because of the difficulty in measuring very low absorption coefficients. The Biogeochemistry and Optics South Pacific Experiment (BIOSOPE) cruise investigated a large range of oceanic regimes, from mesotrophic waters around the Marquesas Islands to hyperoligotrophic waters in the subtropical gyre and eutrophic waters in the upwelling area off Chile. The spectral absorption coefficients of phytoplankton and NAPs were determined using the filter technique, while the CDOM absorption coefficients were measured using a 2 m capillary waveguide. Over the whole transect, the absorption coefficients of both dissolved and particulate components covered approximately two orders of magnitude; in the gyre, they were among the lowest ever reported for open ocean waters. In the oligotrophic and mesotrophic waters, absorption coefficients of phytoplankton and NAPs were notably lower than those measured in other oceanic areas with similar chlorophyll contents, indicating some deviation from the standard chlorophyll‐absorption relationships. The contribution of absorption by NAPs to total particulate absorption showed large vertical and horizontal variations. CDOM absorption coefficients covaried with algal biomass, albeit with a high scatter. The spectral slopes of both NAP and CDOM absorption revealed structured spatial variability in relation with the trophic conditions. The relative contributions of each component to total nonwater absorption were (at a given wavelength) weakly variable over the transect, at least within the euphotic layer.
Impact of the Arctic Ocean Atlantic water layer on Siberian shelf hydrography
Authors: Dmitrenko Igor A. , Kirillov Sergey A. , Tremblay L. Bruno , Bauch Dorothea , Hölemann Jens A. , Krumpen Thomas , Kassens Heidemarie , Wegner Carolyn , Heinemann Günther , Schröder David
Published: August 2010

This paper examines the role of the Arctic Ocean Atlantic water (AW) in modifying the Laptev Sea shelf bottom hydrography on the basis of historical records from 1932 to 2008, field observations carried out in April–May 2008, and 2002–2009 cross‐slope measurements. A climatology of bottom hydrography demonstrates warming that extends offshore from the 30–50 m depth contour. Bottom layer temperature‐time series constructed from historical records links the Laptev Sea outer shelf to the AW boundary current transporting warm and saline water from the North Atlantic. The AW warming of the mid‐1990s and the mid‐2000s is consistent with outer shelf bottom temperature variability. For April–May 2008 we observed on‐shelf near‐bottom warm and saline water intrusions up to the 20 m isobath. These intrusions are typically about 0.2°C warmer and 1–1.5 practical salinity units saltier than ambient water. The 2002–2009 cross‐slope observations are suggestive for the continental slope upward heat flux from the AW to the overlying low‐halocline water (LHW). The lateral on‐shelf wind‐driven transport of the LHW then results in the bottom layer thermohaline anomalies recorded over the Laptev Sea shelf. We also found that polynya‐induced vertical mixing may act as a drainage of the bottom layer, permitting a relatively small portion of the AW heat to be directly released to the atmosphere. Finally, we see no significant warming (up until now) over the Laptev Sea shelf deeper than 10–15 m in the historical record. Future climate change, however, may bring more intrusions of Atlantic‐modified waters with potentially warmer temperature onto the shelf, which could have a critical impact on the stability of offshore submarine permafrost.
Atmospheric distribution and removal of volcanic ash after the eruption of Kasatochi volcano: A regional model study
Authors: Langmann Baerbel , Zakšek Klemen , Hort Matthias
Published: August 2010

In August 2008, Kasatochi volcano on the Aleutian Islands erupted without much advance warning. Volcanic ash released during this eruption quickly settled out of the atmosphere, mainly into the NE Pacific Ocean. The amount of volcanic ash, as well as the ash fall area and volume into the NE Pacific Ocean, remains speculative, as only a limited number of measurements is available. We used a three‐dimensional atmosphere/chemistry‐aerosol model to determine the atmospheric distribution of SO2 and volcanic ash and its fallout after the eruption of Kasatochi volcano. In a first step, modeled atmospheric SO2 distributions are compared with satellite data, thereby evaluating the model capabilities to reasonably reproduce atmospheric transport patterns. For modeled volcanic ash mass a considerable reduction of the atmospheric content already occurred by 10 August, the second day after the eruption in accordance with satellite observations. Gravitational settling is the most efficient removal process for volcanic ash mass, exceeding dry and wet deposition by far. Assuming an ash volume of 0.3 km3 released during the eruption of Kasatochi volcano and a median ash particle diameter of 4 μm, the mass of volcanic ash removed at ground within the 0.1 mm isopach covers an area of 7.6 × 105 km2 over the NE Pacific Ocean and makes up 49% of the removed material out of the atmosphere. The amount of ash and that of iron attached to it is sufficient to explain measured seawater CO2 decrease at the ocean station Papa in August 2008 induced by iron fertilization and subsequent phytoplankton production.
Differentiation of Vesta and the parent bodies of other achondrites
Authors: Gupta G. , Sahijpal S.
Published: August 2010

Numerical simulations have been performed to understand the planetary differentiation of Vesta and other differentiated asteroids. The short‐lived nuclides 26Al and 60Fe were used as the heat sources for the differentiation of asteroids of sizes 20–270 km. The essential aim was to simulate the two proposed differentiation scenarios associated with the formation of the basaltic achondrites. One of these scenarios deals with their origin by partial melting of silicates. The other scenario involves the origin of basalts from the residual melt left subsequent to crystallization in a convective and cooling magma ocean. The core‐mantle differentiation in both the scenarios was commenced subsequent to 40% silicate melting. The partial melt scenario seems to contradict the general trend in the chronological sequence of core‐mantle and mantle‐crust differentiations observed in various differentiated meteorites unless the irons meteorite parent bodies differentiated rapidly compared to prolonged accretion and differentiation of distinct parent bodies of achondrites. Even though the geochemical records of siderophile elements in eucrites favor the residual melt scenario, based on our simulations it is difficult to rapidly and globally cool the magma oceans to produce residual basaltic melts subsequent to crystallization within initial ∼10 million years. This is in contradiction with the chronological records of the basalts that suggest their early origin. In order to make this scenario viable by invoking rapid and global cooling of the magma ocean it would be essential to substantially remove the insulating crust of the planetesimal by continuous bombardment of small planetesimals in the early solar system.
Monochromatic infrasonic tremor driven by persistent degassing and convection at Villarrica Volcano, Chile
Authors: Ripepe M. , Marchetti E. , Bonadonna C. , Harris A. J. L. , Pioli L. , Ulivieri G.
Published: August 2010

Infrasonic data collected at Villarrica volcano (Chile) in March 2009 show a sustained, continuous, infrasonic oscillation (tremor) with a monochromatic low frequency content at ∼0.75 Hz. This tremor is extremely stable in time both at the summit and at a distal (∼4 km) small aperture array. Infrasonic tremor is characterized by discrete high amplitude bursts with a cyclic recurrence time of ∼40 s and is well correlated (0.93) with seismic tremor. These new data are compared with previous datasets collected in 2002 and 2004 during different levels of activity. All data show the same persistent infrasonic tremor and have the same strong correlation with seismic tremor. The stability and correlation of infrasonic and seismic tremor indicate the existence of a sustained and continuous process, which we suggest is related to the gravity‐driven bubble column dynamics responsible for conduit convection.
Monitoring biosphere vegetation 1998–2009
Authors: Gobron N. , Belward A. , Pinty B. , Knorr W.
Published: August 2010

Earth Observation from space offers the opportunity to produce time‐series of geophysical products that can be used to assess the state and changes of land surfaces. The Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) is used to monitor the state and evolution of terrestrial vegetation, and also constitutes a state variable in advanced Earth system models that contain a detailed enough description of the terrestrial biosphere. This present study reports a 12‐year (1998–2009) time series of FAPAR derived from the combination of two satellite‐based sensors. We find that FAPAR exhibits large‐scale inter‐annual variations and multi‐year trends. The fraction of land grid cells showing positive anomalies, as computed by the deviation from the 12‐year climatology, shows a rapid decrease in the early part of the analysis period (until 2004). Large negative anomalies can be associated with previously reported large‐scale climate events, such as global land drying associated with El Niño Southern Oscillation 2000–2003, or the European drought of 2003 or recent Australian droughts The present analysis demonstrates that FAPAR is an important global variable suitable for large‐scale monitoring of climate impacts on the terrestrial biosphere.
Non‐volcanic seismic swarms triggered by circulating fluids and pressure fluctuations above a solidified diorite intrusion
Authors: Kato Aitaro , Sakai Shinichi , Iidaka Takashi , Iwasaki Takaya , Hirata Naoshi
Published: August 2010

A non‐volcanic seismic swarm is often assumed to be tied to fluid movements, based on earthquake migrations obeying a diffusion equation. However, seismological observations that relate to the presence and driving force of migrating fluids are not well documented. Here we present high‐resolution tomographic imaging of seismic velocities in the Wakayama district, Japan, characterized by intense seismic swarms and high heat flow. Earthquake clusters at depths of 4–6 km are distributed within a zone with low‐Vp and anomalously low‐Vp/Vs. The existence of this low‐Vp/Vs anomaly is supported by another estimate using waveform cross‐correlation data from similar event clusters. We suggest that these anomalies are caused by fluid‐filled pores with relatively high aspect ratios. Just beneath the clusters of earthquakes, a prominent high‐velocity zone is clearly imaged. It lacks earthquakes, and could represent a body of intruded diorite related to past volcanism. We propose that non‐volcanic seismic swarms are triggered by circulating fluids and fluid pressure fluctuations driven by the thermal anomaly of the solidified diorite magma.
Human INO80 chromatin-remodelling complex contributes to DNA double-strand break repair via the expression of Rad54B and XRCC3 genes
Authors: Park Eun-Jung , Hur Shin-Kyoung , Kwon Jongbum
Published: August 2010

Recent studies have shown that the SWI/SNF family of ATP-dependent chromatin-remodelling complexes play important roles in DNA repair as well as in transcription. The INO80 complex, the most recently described member of this family, has been shown in yeast to play direct role in DNA DSB (double-strand break) repair without affecting the expression of the genes involved in this process. However, whether this function of the INO80 complex is conserved in higher eukaryotes has not been investigated. In the present study, we found that knockdown of hINO80 (human INO80) confers DNA-damage hypersensitivity and inefficient DSB repair. Microarray analysis and other experiments have identified the Rad54B and XRCC3 (X-ray repair complementing defective repair in Chinese-hamster cells 3) genes, implicated in DSB repair, to be repressed by hINO80 deficiency. Chromatin immunoprecipitation studies have shown that hINO80 binds to the promoters of the Rad54B and XRCC3 genes. Re-expression of the Rad54B and XRCC3 genes rescues the DSB repair defect in hINO80-deficient cells. These results suggest that hINO80 assists DSB repair by positively regulating the expression of the Rad54B and XRCC3 genes. Therefore, unlike yeast INO80, hINO80 can contribute to DSB repair indirectly via gene expression, suggesting that the mechanistic role of this chromatin remodeller in DSB repair is evolutionarily diversified.
Assessing Multimodal Spoken Word-in-Sentence Recognition in Children With Normal Hearing and Children With Cochlear Implants
Authors: Holt Rachael Frush , Kirk Karen Iler , Hay-McCutcheon Marcia
Published: August 2010

Purpose

To examine multimodal spoken word-in-sentence recognition in children.

Method

Two experiments were undertaken. In Experiment 1, the youngest age with which the multimodal sentence recognition materials could be used was evaluated. In Experiment 2, lexical difficulty and presentation modality effects were examined, along with test–retest reliability and validity in normal-hearing children and those with cochlear implants.

Results

Normal-hearing children as young as 3.25 years and those with cochlear implants just under 4 years who have used their device for at least 1 year were able to complete the multimodal sentence testing. Both groups identified lexically easy words in sentences more accurately than lexically hard words across modalities, although the largest effects occurred in the auditory-only modality. Both groups displayed audiovisual integration with the highest scores achieved in the audiovisual modality, followed sequentially by auditory-only and visual-only modalities. Recognition of words in sentences was correlated with recognition of words in isolation. Preliminary results suggest fair-to-good test–retest reliability.

Conclusions

The results suggest that children’s audiovisual word-in-sentence recognition can be assessed using the materials developed for this investigation. With further development, the materials hold promise for becoming a test of multimodal sentence recognition for children with hearing loss.
Influence of Broad Auditory Tuning on Across-Frequency Integration of Speech Patterns
Authors: Healy Eric W. , Carson Kimberly A.
Published: August 2010

Purpose

The purpose of the present study was to assess whether diminished tolerance for disruptions to across-frequency timing in listeners with hearing impairment can be attributed to broad auditory tuning.

Method

In 2 experiments in which random assignment was used, sentences were represented as 3 noise bands centered at 530, 1500, and 4243 Hz, which were amplitude modulated by 3 corresponding narrow speech bands. To isolate broad tuning from other influences of hearing impairment, listeners with normal hearing (45 in Experiment 1 and 30 in Experiment 2) were presented with these vocoder stimuli, having carrier band filter slopes of 12, 24, and 192 dB/octave. These speech patterns were presented in synchrony and with between-band asynchronies up to 40 ms.

Results

Mean intelligibility scores were reduced in conditions of severe, but not moderate, simulated broadening. Although scores fell as asynchrony increased, the steeper drop in performance characteristic of listeners with hearing impairment tested previously was not observed in conditions of simulated broadening.

Conclusions

The intolerance for small across-frequency asynchronies observed previously does not appear attributable to broad tuning. Instead, the present data suggest that the across-frequency processing mechanism in at least some listeners with hearing impairment might be less robust to this type of degradation.
Measuring the Effects of Reverberation and Noise on Sentence Intelligibility for Hearing-Impaired Listeners
Authors: George Erwin L. J. , Goverts S. Theo , Festen Joost M. , Houtgast Tammo
Published: August 2010

Purpose

The Speech Transmission Index (STI; Houtgast, Steeneken, & Plomp, 1980; Steeneken & Houtgast, 1980) is commonly used to quantify the adverse effects of reverberation and stationary noise on speech intelligibility for normal-hearing listeners. Duquesnoy and Plomp (1980) showed that the STI can be applied for presbycusic listeners, relating speech reception thresholds (SRTs) in various reverberant conditions to a fixed, subject-dependent STI value. The current study aims at extending their results to a wider range of hearing-impaired listeners.

Method

A reverberant analogue of the SRT is presented—the speech reception reverberation threshold (SRRT)—which determines the amount of reverberation that a listener can sustain to understand 50% of the presented sentences. SRTs are performed and evaluated in terms of STI for 5 normal-hearing participants and 36 randomly selected hearing-impaired participants.

Results

Results show that differences in STI between reverberant and noisy conditions are only small, equivalent to a change in speech-to-noise ratio < 1.3 dB.

Conclusion

The STI appears to be a convenient, single number to quantify speech reception of hearing-impaired listeners in noise and/or reverberation, regardless of the nature of the hearing loss. In future research, the SRRT may be applied to further investigate the supposed importance of cognitive processing in reverberant listening conditions.