bluuebunny/crossref_metadata_2025_split huggingface dataset:
Air pollution and carotid arterial stiffness in children
Authors: Iannuzzi Arcangelo , Verga Maria Carmela , Renis Maurizio , Schiavo Alfonso , Salvatore Vittorio , Santoriello Carlo , Pazzano Dario , Licenziati Maria Rosaria , Polverino Mario 
Published: March 2010

AbstractBackground and purposeMany studies unequivocally indicate that air pollution is directly linked to the adverse cardiovascular outcomes in the general population. No data are currently available on cardiovascular effects of exposure to trafficked roads in healthy children. Distance of the residence to a major road has been shown to be a useful proxy for long-term traffic exposure and seem to be more consistently associated with atherosclerosis than particulate matter2.5. The aim of this study was to investigate a possible association between the distance to a major road and carotid arterial subclinical markers of atherosclerosis in a group of children in Italy.MethodsThe participants consisted of 52 healthy children living in a small town of the Amalphitan Coast with only one highly trafficked road. All children underwent an ultrasound carotid arterial examination.ResultsA statistically significant difference was found in carotid arterial stiffness between children living closer to the main street and other children, both those living between 330 and 730 metres from the main street and those living more than 750 metres from the main street. No significant differences were detectable in carotid arterial thickness and arterial blood pressure among the three groups of children.ConclusionThis study provides evidence in support of an association of exposure to air pollution with early atherosclerotic markers in healthy children. Impaired vascular health in childhood and adolescence gives further substance to the hypothesis that traffic exhausts are relevant to cardiovascular diseases even early in life.
Information Matters: Government's Strategy to Build Capability in Managing Its Knowledge and Information Assets
Authors: Woolf Katie 
Published: March 2010

AbstractThis article by Katie Woolf, formerly of the Government Knowledge and Information Network, looks at the new UK Government strategy for knowledge and information (KIM). Led by the Knowledge Council, the strategy sets out the principles and actions government must take to develop the capability it needs to manage corporate knowledge and information as the key business assets they are. It discusses how the strategy will be achieved through a departmental delivery model, the relationship of the strategy with the Information Assurance agenda post data loss scandals, and the need for senior leader engagement to be the driving force to building a culture that values KIM.
Indexing of Free, Web-based Electronic Resources
Authors: Browne Glenda 
Published: March 2010

AbstractThe internet provides access to a huge amount of information, and most people experience problems with information overload rather than scarcity. Glenda Browne explains how indexing provides a way of increasing retrieval of relevant information from the content available. Manual, book-style indexes can be created for websites and individual web documents such as online books. Keyword metadata is a crucial behind the scenes aid to improved search engine functioning, and categorisation, social bookmarking and automated indexing also play a part.
AlGaN/GaN epitaxy and technology
Authors: Waltereit Patrick , Bronner Wolfgang , Quay Rüdiger , Dammann Michael , Kiefer Rudolf , Pletschen Wilfried , Müller Stefan , Aidam Rolf , Menner Hanspeter , Kirste Lutz , Köhler Klaus , Mikulla Michael , Ambacher Oliver 
Published: March 2010

We present an overview on epitaxial growth, processing technology, device performance, and reliability of our GaN high electron mobility transistors (HEMTs) manufactured on 3- and 4-in. SiC substrates. Epitaxy and processing are optimized for both performance and reliability. We use three different gate lengths, namely 500 nm for 1–6 GHz applications, 250 nm for devices between 6 and 18 GHz, and 150 nm for higher frequencies. The developed HEMTs demonstrate excellent high-voltage stability, high power performance, and large DC to RF conversion efficiencies for all gate lengths. On large gate width devices for base station applications, an output power beyond 125 W is achieved with a power added efficiency around 60% and a linear gain around 16 dB. Reliability is tested both under DC and RF conditions with supply voltage of 50 and 30 V for 500 and 250 nm gates, respectively. DC tests on HEMT devices return a drain current change of just about 10% under IDQ conditions. Under RF stress the observed change in output power density is below 0.2 dB after more than 1000 h for both gate length technologies.
Evaluation of GaN technology in Doherty power amplifier architectures
Authors: Colantonio Paolo , Giannini Franco , Giofrè Rocco , Piazzon Luca 
Published: March 2010

The aim of the present paper is to highlight the possible benefits coming from the use of the GaN high electron-mobility transistor (HEMT) technology in the Doherty power amplifier (DPA) architecture. In particular, the attention is focused on the capabilities and the relevant drawbacks of a GaN HEMT technology when designing DPAs. A deep discussion of the DPA's design guidelines is also presented through the realization of three prototypes implementing different design solutions and working at 2.14 GHz. The first example is a tuned load DPA (TL-DPA), which show an average drain efficiency of 40.7% with 3 W of saturated output power in the obtained 6 dB of output back-off. The second DPA was designed implementing a class F harmonic termination for the main device, which allows an improvement of roughly 15% in output power and efficiency behavior with respect to the TL-DPA. The last DPA was realized implementing a single output matching network for both main and auxiliary devices, which allows a relevant reduction in the size of the resulting DPA, without downgrading the overall performances.
Nitrogen and phosphorus enrichment alter the composition of ammonia-oxidizing bacteria in salt marsh sediments
Authors: Lage Melissa D , Reed Heather E , Weihe Claudia , Crain Caitlin M , Martiny Jennifer B H 
Published: March 2010

Abstract
Ammonia oxidation is a central process in the nitrogen cycle. Particularly in marine and estuarine environments, few experiments have been conducted to tease apart the factors influencing their abundance and composition. To investigate the effect of nitrogen and phosphorus availability on ammonia-oxidizing bacteria (AOB), we conducted a nutrient enrichment experiment in a Maine salt marsh and sampled sediment communities in three seasons over 2 years. We assessed community composition using terminal restriction fragment length polymorphism analysis and sequencing of cloned fragments of the ammonia monooxygenase (amoA) gene. Almost all of the amoA sequences fell within the marine and estuarine-specific Nitrosospira-like clade. Applied separately, nitrogen and phosphorus significantly altered AOB composition; however, together the nutrients had an interactive effect, and composition did not change. In contrast, nutrient enrichment did not alter AOB abundance. Furthermore, the response of AOB composition to nutrient enrichment varied over time. We conclude that closely related taxa within the marine/estuarine-specific Nitrosospira-like clade vary in their preference for nutrient concentrations, and this preference may depend on other temporally variable abiotic factors. Finally, AOB composition was highly variable within and across years even in untreated plots. Further studies are needed to test how these different aspects of compositional variability in AOB communities influence nitrogen cycling.
Silica deposition and phenotypic changes to Thermus thermophilus cultivated in the presence of supersaturated silicia
Authors: Iwai Satoru , Doi Katsumi , Fujino Yasuhiro , Nakazono Takeo , Fukuda Kosai , Motomura Yoshinobu , Ogata Seiya 
Published: March 2010

Abstract
Thermus thermophilus cells formed siliceous deposits in the presence of supersaturated silicic acid (600 p.p.m SiO2). The supersaturated silicic acid promoted interaction between cells and the inside walls of glass culture bottles, leading to the development of cell aggregates or biofilms. Electron probe microanalysis showed that within the aggregates most of the cell surfaces were covered with silica. Under these conditions, there was remarkable production of silica-induced protein (Sip), a solute-binding component of the Fe3+-binding ABC transporter. Furthermore, supersaturated silica enhanced resistance to the peptide antibiotics bacitracin, colistin and polymyxin B, which all act on the cell envelope. By contrast, supersaturated silica did not induce resistance to ampicillin, chloramphenicol, kanamycin and tetracycline, which inhibit peptide synthesis. Although strong expression of Sip was detected in liquid cultures of T. thermophilus in the presence of supersaturated silica and colistin, upregulated transcription of putative efflux pump and multidrug resistance ABC transporter genes were not detected by quantitative real-time PCR analysis. These findings suggest Sip promotes silica deposition on the surfaces of cells, after which the silicified outer membrane may serve as a ‘suit-of-armor,’ conferring resistance to peptide antibiotics.
Development and quantitative analyses of a universal rRNA-subtraction protocol for microbial metatranscriptomics
Authors: Stewart Frank J , Ottesen Elizabeth A , DeLong Edward F 
Published: March 2010

AbstractMetatranscriptomes generated by pyrosequencing hold significant potential for describing functional processes in complex microbial communities. Meeting this potential requires protocols that maximize mRNA recovery by reducing the relative abundance of ribosomal RNA, as well as systematic comparisons to identify methodological artifacts and test for reproducibility across data sets. Here, we implement a protocol for subtractive hybridization of bacterial rRNA (16S and 23S) that uses sample-specific probes and is applicable across diverse environmental samples. To test this method, rRNA-subtracted and unsubtracted transcriptomes were sequenced (454 FLX technology) from bacterioplankton communities at two depths in the oligotrophic open ocean, yielding 10 data sets representing ∼350 Mbp. Subtractive hybridization reduced bacterial rRNA transcript abundance by 40–58%, increasing recovery of non-rRNA sequences up to fourfold (from 12% to 20% of total sequences to 40–49%). In testing this method, we established criteria for detecting sequences replicated artificially via pyrosequencing errors and identified such replicates as a significant component (6–39%) of total pyrosequencing reads. Following replicate removal, statistical comparisons of reference genes (identified via BLASTX to NCBI-nr) between technical replicates and between rRNA-subtracted and unsubtracted samples showed low levels of differential transcript abundance (&lt;0.2% of reference genes). However, gene overlap between data sets was remarkably low, with no two data sets (including duplicate runs from the same pyrosequencing library template) sharing greater than 17% of unique reference genes. These results indicate that pyrosequencing captures a small subset of total mRNA diversity and underscores the importance of reliable rRNA subtraction procedures to enhance sequencing coverage across the functional transcript pool.
Novel observations of Thiobacterium, a sulfur-storing Gammaproteobacterium producing gelatinous mats
Authors: Grünke Stefanie , Lichtschlag Anna , Beer Dirk , Kuypers Marcel , Lösekann-Behrens Tina , Ramette Alban , Boetius Antje 
Published: March 2010

Abstract
The genus Thiobacterium includes uncultivated rod-shaped microbes containing several spherical grains of elemental sulfur and forming conspicuous gelatinous mats. Owing to the fragility of mats and cells, their 16S ribosomal RNA genes have not been phylogenetically classified. This study examined the occurrence of Thiobacterium mats in three different sulfidic marine habitats: a submerged whale bone, deep-water seafloor and a submarine cave. All three mats contained massive amounts of Thiobacterium cells and were highly enriched in sulfur. Microsensor measurements and other biogeochemistry data suggest chemoautotrophic growth of Thiobacterium. Sulfide and oxygen microprofiles confirmed the dependence of Thiobacterium on hydrogen sulfide as energy source. Fluorescence in situ hybridization indicated that Thiobacterium spp. belong to the Gammaproteobacteria, a class that harbors many mat-forming sulfide-oxidizing bacteria. Further phylogenetic characterization of the mats led to the discovery of an unexpected microbial diversity associated with Thiobacterium.
An Experimental Investigation of the Effect of Altered Auditory Feedback on the Conversational Speech of Adults Who Stutter
Authors: Lincoln Michelle , Packman Ann , Onslow Mark , Jones Mark 
Published: March 2010

Purpose
To investigate the impact on percentage of syllables stuttered of various durations of delayed auditory feedback (DAF), levels of frequency-altered feedback (FAF), and masking auditory feedback (MAF) during conversational speech.

Method
Eleven adults who stuttered produced 10-min conversational speech samples during a control condition and under 4 different combinations of DAF, FAF, and MAF. Participants also read aloud in a control condition with DAF and FAF.

Results
A statistically significant difference was found between the NAF conversation condition and the 4 combined altered auditory feedback (AAF) conditions. No statistically significant differences in percentage of syllables stuttered were found in conversation or reading between the control conditions and the FAF/DAF or MAF conditions. The analysis of individual participants' data showed highly individual responsiveness to different conditions.

Conclusions
Participants' varying responses to differing AAF settings likely accounted for the failure to find group differences between conditions. These results suggest that studies that use standard DAF and FAF settings for all participants are likely to underestimate any AAF effect. It is not yet possible to predict who will benefit from AAF devices in everyday situations and the extent of those benefits.
An On-Line Imitative Test of Speech-Pattern Contrast Perception (OlimSpac): Developmental Effects in Normally Hearing Children
Authors: Boothroyd Arthur , Eisenberg Laurie S. , Martinez Amy S. 
Published: March 2010

Purpose
The goal was to assess the effects of maturation and phonological development on performance, by normally hearing children, on an imitative test of auditory capacity (On-Line Imitative Test of Speech-Pattern Contrast Perception [OlimSpac]; Boothroyd, Eisenberg, & Martinez, 2006; Eisenberg, Martinez, & Boothroyd, 2003, 2007).

Method
Thirty-four hearing children (aged between 1;8 [years;months] and 6;7) were asked to imitate nonword utterances. Responses were evaluated by a blinded listener in an 8-alternative forced-choice task, giving information on the children’s ability to convey, by imitation, information about 6 binary phonemic contrasts.

Results
Four children declined participation. Among 30 children aged 2;7 or older, performance improved significantly with age and varied with contrast. All children 3 years of age or older attained passing scores (7 or 8 correct responses in 8 binary trials) on at least 5 of the 6 contrasts. Post-alveolar consonant place was the contrast most often failed.

Conclusions
When evaluated on a pass/fail basis, normally hearing children 3 years of age or older are likely to demonstrate auditory perception of most phonemic contrasts using this imitative test. Phonological development and other task-related factors have only a modest effect on performance by normally hearing children after 3 years of age. The effects of hearing loss, hearing age, sensory assistance, and listening experience in children with hearing loss remain to be determined.
Evidence That a Motor Timing Deficit Is a Factor in the Development of Stuttering
Authors: Olander Lindsey , Smith Anne , Zelaznik Howard N. 
Published: March 2010

Purpose
To determine whether young children who stutter have a basic motor timing and/or a coordination deficit.

Method
Between-hands coordination and variability of rhythmic motor timing were assessed in 17 children who stutter (4–6 years of age) and 13 age-matched controls. Children clapped in rhythm with a metronome with a 600-ms interbeat interval and then attempted to continue to match this target rate for 32 unpaced claps.

Results
Children who stutter did not significantly differ from children who were typically developing on mean clapping rate or number of usable trials produced; however, they produced remarkably higher variability levels of interclap interval. Of particular interest was the bimodal distribution of the stuttering children on clapping variability. One subgroup of children who stutter clustered within the normal range, but 60% of the children who stutter exhibited timing variability that was greater than the poorest performing nonstuttering child. Children who stutter were not more variable in measures of coordination between the 2 hands (mean and median phase difference between hands).

Conclusion
We infer that there is a subgroup of young stuttering children who exhibit a nonspeech motor timing deficit, and we discuss this result as it pertains to recovery or persistence of stuttering.
Perception of Acoustically Degraded Sentences in Bilingual Listeners Who Differ in Age of English Acquisition
Authors: Shi Lu-Feng 
Published: March 2010

PurposeThe effects of acoustic degradation and context use on sentence perception were evaluated in listeners differing in age of English acquisition.MethodFive groups of 8 listeners, native monolingual (NM), native bilingual (NB), and early, late, and very late non-native bilingual (NN-E, NN-L, and NN-VL, respectively), identified target words in 400 Speech-Perception-in-Noise (SPIN) sentences presented in 8 combinations of noise (+6 vs. 0 dB signal-to-noise ratio), reverberation (1.2 vs. 3.6 s reverberation time), and context (high vs. low predictability).ResultsSeparate effects of noise, reverberation, and context were largely level dependent and more significant than their interaction with listeners' age of English acquisition. However, the effect of noise, as well as the combined effect of reverberation and context, was mediated by age of acquisition. NN-VL listeners' performance was significantly compromised in all test conditions. NB, NN-E, and NN-L listeners' use of context, by contrast, deviated substantially from the monolingual normative in difficult listening conditions.ConclusionsFindings suggest that linguistic background needs to be considered in the understanding of bilingual listeners' context use in acoustically degraded conditions. Direct comparison of early bilingual listeners' performance with monolingual norms may be inappropriate when speech is highly degraded.
Using Language Sampling to Measure Language Growth
Authors: Rojas Raúl , Iglesias Aquiles 
Published: March 2010

Abstract
This article illustrates how speech-language pathologists (SLPs) can use language sampling and growth curve modeling (GCM) to examine the language growth rates of English Language Learners. GCM data on language samples provides SLPs with powerful, new tools to evaluate actual progress over time instead of relying on single, static measurement endpoints to determine typical development.
A Survey of IUE Spectra of the Active Binary System UX Arietis
Authors: Ekmekçi Fehmi 
Published: March 2010

AbstractTo investigate the ultraviolet (UV) activity of the bright, non-eclipsing, double-lined spectroscopic binary system UX Ari, IUE spectra (194 images) were taken from the IUE archive. The spectra, obtained during the period 1978–1996, show emission lines originating in the chromosphere and transition region. The long-wavelength low dispersion spectra were examined for ultraviolet excess by comparing the UV continuum level of UX Ari with the levels of k Cet and η Cep in the spectral range 2100–3200 Å. The individual Mgiih and k emission-line fluxes of component stars show that the contributions to the activity of the system for G5 V and K0 IV are about 20% and 80%, respectively. Apart from the flare event observed on 1979 Jan 1, there are some flux enhancements in the years 1987, 1991 and 1994 which may suggest existence of a periodicity of about 7–9 years. Examination of the ultraviolet excess in the system showed that there is some UV excess in UX Ari, which varies from 1% up to 24% with the exception of two images which showed no UV excess. The results revealed that there was an agreement on the source of emission regions which could be attributed to magnetic activity. The contribution of G5 V and K0 IV components to the Mgii activity of the system suggests a need to take into consideration the spot distribution not only on the surface of the K0 IV but also on the surface of the G5 V component of UX Ari.
Stellar Over-Densities in the Outer Halo of the Milky Way
Authors: Keller Stefan C. 
Published: March 2010

AbstractThis study presents a tomographic survey of a subset of the outer halo (10–40 kpc) drawn from the Sloan Digital Sky Survey Data Release 6. Halo substructure on spatial scales of >3 degrees is revealed as an excess in the local density of sub-giant stars. With an appropriate assumption of a model stellar isochrone it is possible for us to then derive distances to the sub-giant population. We describe three new candidate halo substructures; the 160- and 180-degree over-densities (at distances of 17 and 19 kpc respectively and radii of 1.3 and 1.5 kpc respectively) and an extended feature at 28 kpc that covers at least 162 deg2, the Virgo Equatorial Stream. In addition, we recover the Sagittarius dwarf galaxy (Sgr) leading-arm material and the Virgo Over-Density.The derived distances, together with the number of sub-giant stars associated with each substructure, enables us to derive the integrated luminosity for the features. The tenuous, low surface brightness of the features strongly suggests an origin from the tidal disruption of an accreted galaxy or galaxies. Given the dominance of the tidal debris of Sgr in this region of the sky we investigate if our observations can be accommodated by tidal disruption models for Sgr. The clear discordance between observations and model predictions for known Sgr features means it is difficult to tell unambiguously if the new substructures are related to Sgr or not. Radial velocities in the stellar over-densities will be critical in establishing their origins.
The Adventures of the Rocketeer: Accelerated Motion Under the Influence of Expanding Space
Authors: Kwan Juliana , Lewis Geraint F. , James J. Berian 
Published: March 2010

AbstractIt is well known that interstellar travel is bounded by the finite speed of light, but on very large scales any rocketeer would also need to consider the influence of cosmological expansion on their journey. This paper examines accelerated journeys within the framework of Friedmann–Lemaître–Robertson–Walker universes, illustrating how the duration of a fixed acceleration sharply divides exploration over interstellar and intergalactic distances. Furthermore, we show how the universal expansion increases the difficulty of intergalactic navigation, with small uncertainties in cosmological parameters resulting in significantly large deviations. This paper also shows that, contrary to simplistic ideas, the motion of any rocketeer is indistinguishable from Newtonian gravity if the acceleration is kept small.