bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutritional status and dietary adequacy in rural communities of a protected area in Gabon
Authors: Blaney S , Beaudry M , Latham M , Thibault M
Published: April 2009

Objective

As part of a larger study designed to understand how to protect the food and nutrition security of individuals living in a protected area of Gabon, we assessed their nutritional status and its relationship to dietary adequacy and health status.

Design

A 7 d food consumption survey was conducted during each of the two major seasons using a weighing method. Data were also collected on weight, height and health of individuals as well as on sociodemographic characteristics and potential determinants of the nutrition situation.

Setting

Four rural communities were intentionally selected to represent both inland and coastal settings and access to food markets.

Subjects

Approximately 500 individuals representing over 90 % of the population of these communities participated in the survey during each season.

Results

Undernutrition was present in the area, particularly among children <5 years of age and the elderly. Health was generally good and under-fives were most frequently ill. Energy, Fe and vitamin A requirements of individuals were generally not satisfied; the opposite was true for protein. The estimated prevalence of inadequate intakes of energy and vitamin A was very high in most age groups. Global nutrient adequacy was associated with nutritional outcome.

Conclusions

Individuals do not eat enough and breast-feeding practices are poor. Many suffer from undernutrition, particularly young children and the elderly. The results confirm the need to investigate the determinants of this poor nutrition situation to ensure that protection of natural resources will not be associated with harm to the well-being of the population.
Die Hyponatriämie der Frau L.
Authors: Osinga  , Hess-Sigrist  , Wegener  , Wiens  , Hess
Published: April 2009

Wir berichten über eine 84-jährige Patientin, die im Rahmen eines lokalisierten Herpes Zoster ein Syndrom der inadäquaten ADH-Sekretion (SIADH) mit schwerer Hyponatriämie entwickelt hat. Dies ist eine seltene, aber bekannte Komplikation der lokalisierten Varizella-Zoster-Infektion. Unter Trinkmengenrestriktion und Zufuhr salzreicher Nahrung zeigte sich eine Normalisierung des Serumnatriums, und gut ein Monat nach Spitalentlassung zeigte sich ohne Diät ein normaler Natriumwert.
Ethische Führung – Gütekriterien einer deutschen Adaptation der Ethical Leadership Scale (ELS-D) von
Authors: Rowold Jens , Borgmann Lars , Heinitz Kathrin
Published: April 2009

Ziel des vorliegenden Beitrages ist, die Gütekriterien eines Instruments zur Erfassung von ethischer Führung zu überprüfen. Ausgangspunkt war die Übersetzung der Ethical Leadership Scale von Brown, Trevino und Harrison (2005) ins Deutsche (ELS-D). Anschließend wurde anhand dreier Stichproben (N1 = 100, N2 = 119, N3 = 507) die faktorielle Binnenstruktur des Instrumentes überprüft. Es ergaben sich zwei Faktoren (ethische Mitarbeiterführung und ethisches Rollenmodell). Es zeigten sich konvergente Validitäten zwischen den Skalen ethischer Führung und transformationaler, transaktionaler, mitarbeiter- und aufgabenorientierter Führung (positive Korrelationen) sowie Laissez-faire (negative Korrelation). Demgegenüber waren die Skalen ethischer Führung erwartungskonform überwiegend unabhängig vom Alter der geführten Mitarbeiter und vom Geschlecht der Führungskraft. Hohe Zusammenhänge zwischen ethischer Führung und der Arbeitszufriedenheit sowie dem Commitment der Mitarbeiter werden als Belege für die Konstruktvalidität gewertet. Die interne Konsistenz der ELS-D-Skalen war in allen drei empirischen Studien gut. Insgesamt steht mit der hier vorgestellten deutschen Adaptation der ELS ein ökonomisches Instrument mit ansprechenden Gütekriterien für den Einsatz bereit.
FACT-2 – The Frankfurt Adaptive Concentration Test
Authors: Goldhammer Frank , Moosbrugger Helfried , Krawietz Sabine A.
Published: April 2009

The Frankfurt Adaptive Concentration Test (FACT-2) requires discrimination between geometric target and nontarget items as quickly and accurately as possible. Three forms of the FACT-2 were constructed, namely FACT-I, FACT-S, and FACT-SR. The aim of the present study was to investigate the convergent validity of the FACT-SR with self-reported cognitive failures. The FACT-SR and the Cognitive Failures Questionnaire (CFQ) were completed by 191 participants. The measurement models confirmed the concentration performance, concentration accuracy, and concentration homogeneity dimensions of FACT-SR. The four dimensions of the CFQ (i.e., memory, distractibility, blunders, and names) were not confirmed. The results showed moderate convergent validity of concentration performance, concentration accuracy, and concentration homogeneity with two CFQ dimensions, namely memory and distractibility/blunders.
The Real Animal Size Test (RAST)
Authors: Catale Corinne , Meulemans Thierry
Published: April 2009

Inhibitory control disturbances are reported in numerous developmental and acquired neuropsychological disorders of young children. In this study, a new assessment tool, the Real Animal Size Test (RAST) was tested. It includes four conditions: The first two conditions assess speed of processing and require making quick decisions, by pressing a response key, on the real size of animals and the on-screen size of big or small rectangles; the third and fourth condition (combined into one) require the child to decide the real size of animals displayed in congruent or incongruent size on the screen. Participants in the study were 90 children aged 5–9 years old. The results confirmed that the RAST provides a good measure of inhibitory control in children. In a second experiment, 15 children 5–9 years old with attention deficit and hyperactivity disorder symptoms (ADHD) participated; the RAST was also administered. The clinical pertinence of the RAST for ADHD symptoms is discussed.
Working Memory, but Not IQ, Predicts Subsequent Learning in Children with Learning Difficulties
Authors: Alloway Tracy Packiam
Published: April 2009

The purpose of the present study was to compare the predictive power of working memory and IQ in children identified as having learning difficulties. The term “working memory” refers to the capacity to store and manipulate information in mind for brief periods of time. Working-memory capacity is strongly related to learning abilities and academic progress, predicting current and subsequent scholastic attainment of children across the school years in both literacy and numeracy. Children aged between 7 and 11 years were tested at Time 1 on measures of working memory, IQ, and learning. They were then retested 2 years later on the learning measures. The findings indicated that working-memory capacity and domain-specific knowledge at Time 1, but not IQ, were significant predictors of learning at Time 2. The implications for screening and intervention are discussed.
Assessing Cognitive Interference Using the Emotional Stroop Task in Students with and Without Attention Problems
Authors: Sideridis Georgios D.
Published: April 2009

The present study describes the Emotional Stroop Task as a means to assess cognitive interference triggered by emotional stimuli in elementary school students with and without attention problems. Using the Emotional Stroop Task in a computerized environment and employing samples of students with and without attention problems (111 without and 29 with attention problems), results indicated that prolonged latencies to stimuli with heavy emotional content related to their school experiences were predictive of students’ membership, after controlling for their gender and grade levels. These effects were independent of students’ processing ability as indicated by the lack of significant differences in reaction time to neutral stimuli. It is concluded that the Emotional Stroop Task can be used to assess cognitive interference in emotionally charged conditions across groups of students.
Jökulhlaup Observed at Greenland Ice Sheet
Authors: Mernild Sebastian H. , Hasholt Bent , Kane Douglas L. , Tidwell Amy C.
Published: April 2009

On 31 August 2007, about 35 kilometers upstream from the town of Kangerlussuaq, in western Greenland, a roughly 0.5‐square‐kilometer permanently ice‐dammed lake on the northern flank of the Russell Glacier—an outlet glacier of the Greenland Ice Sheet—suddenly broke free and drained into the Watson River (Figure 1). A 25‐meter drop in the lake water level resulted over an approximately 17‐hour period (Figure 3a). A glacial outburst such as this is known by the Icelandic term jökulhlaup, derived from the words jökull (glacier) and hlaup (meaning sprint or burst) [Robert, 2005].

Before 2007, the last known jökulhlaup from this glacier was in July 1987; jökulhlaups at this location occur once every 8–10 years on average. The 2007 jökulhlaup occurred after the most intensive melt season—with the biggest melting area and melt index (defined as the melting area times the number of melting days)— on the Greenland Ice Sheet since the first satellite observations in 1979 [Tedesco, 2007]. The ice dam broke after 4 days with a temperature range of 4.0°–17.0°C, averaging 9.5°C, resulting in glacier ablation, and with a rainfall total of 33 millimeters (Figure 2a).
Tackling Substorm Problems: New Observational and Modeling Capabilities: Ninth International Conference on Substorms; Graz, Austria, 5–9 May 2008
Authors: Nakamura R. , Baumjohann W.
Published: April 2009

Geomagnetic substorms, responsible for creating brightly lit aurorae that can disrupt satellite communications and electric power grids, comprise a wealth of dynamic plasma processes. These processes and their interplay were discussed by about 130 scientists at a conference at Austria's Seggau Castle, organized by the Space Research Institute of the Austrian Academy of Sciences.

Recent advances in observational and computational capabilities have allowed closer comparison between observation and theory on current sheet instabilities associated with reconnection, ballooning modes, and different wave properties. For example, presentations at the meeting showed how theory combined with observations from ESA's Cluster satellite helped scientists conclude that the formation of an embedded current sheet occurred before the growth of the instability rather than from thinning the entire plasma sheet. Additionally, the evolution of instabilities leading to magnetic reconnection was reported by several theoretical studies at the meeting, which were complemented by presentations of in situ observations seen from Cluster and NASA's Time History of Events and Macroscale Interactions During Substorms (THEMIS) mission that detailed the characteristics of the reconnecting current sheet. Observations at the inner magnetosphere where the magnetic field configuration changes from tail‐like to dipolar fields showed that instabilities such as ballooning modes are needed to explain the initial auroral arc formation near the equatorward edge of plasma sheet electron precipitation.
Dry Climate Disconnected the Laurentian Great Lakes
Authors: Lewis C. F. Michael , King John W. , Blasco Stefan M. , Brooks Gregory R. , Coakley John P. , Croley Thomas E. , Dettman David L. , Edwards Thomas W. D. , Heil Clifford W. , Hubeny J. Bradford , Laird Kathleen R. , McAndrews John H. , McCarthy Francine M. G. , Medioli Barbara E. , Moore Theodore C. , Rea David K. , Smith Alison J.
Published: April 2009

Recent studies have produced a new understanding of the hydrological history of North America's Great Lakes, showing that water levels fell several meters below lake basin outlets during an early postglacial dry climate in the Holocene (younger than 10,000 radiocarbon years, or about 11,500 calibrated or calendar years before present (B.P.)). Water levels in the Huron basin, for example, fell more than 20 meters below the basin overflow outlet between about 7900 and 7500 radiocarbon (about 8770–8290 calibrated) years B.P. Outlet rivers, including the Niagara River, presently falling 99 meters from Lake Erie to Lake Ontario (and hence Niagara Falls), ran dry. This newly recognized phase of low lake levels in a dry climate provides a case study for evaluating the sensitivity of the Great Lakes to current and future climate change.
Widespread Secondary Volcanism Near Northern Hawaiian Islands
Authors: Garcia Michael , Ito Garrett , Weis Dominique , Geist Dennis , Swinnard Lisa , Bianco Todd , Flinders Ashton , Taylor Brian , Appelgate Bruce , Blay Chuck , Hanano Diane , Silva Inês Nobre , Naumann Terry , Maerschalk Claude , Harpp Karen , Christensen Branden , Sciaroni Linda , Tagami Taka , Yamasaki Seiko
Published: April 2009

Hot spot theory provides a key framework for understanding the motion of the tectonic plates, mantle convection and composition, and magma genesis. The age‐progressive volcanism that constructs many chains of islands throughout the world's ocean basins is essential to hot spot theory. In contrast, secondary volcanism, which follows the main edifice building stage of volcanism in many chains including the Hawaii, Samoa, Canary, Mauritius, and Kerguelen islands, is not predicted by hot spot theory. Hawaiian secondary volcanism occurs hundreds of kilometers away from, and more than 1 million years after, the end of the main shield volcanism, which has generated more than 99% of the volume of the volcano's mass [Macdonald et al., 1983; Ozawa et al., 2005]. Diamond Head, in Honolulu, is the first and classic example of secondary volcanism.
U.S. Federal Water Quality Web Service Collaboration
Authors: Scott Jonathon , Gellenbeck Dorinda , Young Dwane , Booth Nathaniel
Published: April 2009

The U.S. Geological Survey (USGS) and the U.S. Environmental Protection Agency (USEPA) have developed collaborative capabilities for the retrieval of water quality data using the World Wide Web [Young, 2008]. Since September 2008, these new capabilities have facilitated searches of millions of analytical measurements from water quality samples collected during the past 100 years. The new system improves, in several ways, on the previous approach to obtaining data from these agencies, and it establishes a framework for future enhancements. As a result of creating these capabilities, an investigator will be able to explore the entire USGS and USEPA water quality data holdings without needing to know which agency manages the desired data.
What Do Lakes and Reservoirs Tell Us About Climate Change?: Chapman Conference on Lakes as Sentinels, Integrators, and Regulators of Climate Change; Incline Village, Nevada, 8–10 September 2008
Authors: Williamson Craig E. , Saros Jasmine E.
Published: April 2009

Where are scientists likely to find the clearest signals of climate change so that they can predict future impacts? The question of where we focus our sampling efforts is not a trivial one due to the complex nature of the landscape of the Earth and the wide and varied impacts of both humans and natural processes on the landscape. As the lowest point in the landscape and as hot spots of carbon cycling, lakes and reservoirs may provide an answer. These inland waters play a disproportionate role in informing us about climate change. They also play an important role in regulating climate change by their contributions to the global carbon cycle.
Judy C. Holoviak Receives Edward A. Flinn III Award
Authors: Hornberger George M. , Holoviak Judy C.
Published: April 2009

Judy C. Holoviak received the Flinn Award at the AGU Meeting of the Americas in 2008. The award honors ‘individuals who personify the Union's motto ‘unselfish cooperation in research’ through their facilitating, coordinating, and implementing activities.”
An Introduction to Ocean Turbulence
Authors: MacKinnon Jennifer
Published: April 2009

In an address to the British Association for the Advancement of Science in 1932, Sir Horace Lamb commented, “I am an old man now, and when I die and go to heaven there are two matters on which I hope for enlightenment. One is quantum electrodynamics, and the other is the turbulent motion of fluids. And about the former I am rather optimistic.” Over the past century, understanding turbulent mixing in the ocean has been one of the most interesting and challenging problems of physical oceanography.
Global ocean wind power sensitivity to surface layer stability
Authors: Capps Scott B. , Zender Charles S.
Published: April 2009

Global ocean wind power has recently been assessed (W. T. Liu et al., 2008) using scatterometry‐based 10 m winds. We characterize, for the first time, wind power at 80 m (typical wind turbine hub height) above the global ocean surface, and account for the effects of surface layer stability. Accounting for realistic turbine height and atmospheric stability increases mean global ocean wind power by +58% and −4%, respectively. Our best estimate of mean global ocean wind power is 731 W m−2, about 50% greater than the 487 W m−2 based on previous methods. 80 m wind power is 1.2–1.5 times 10 m power equatorward of 30° latitude, between 1.4 and 1.7 times 10 m power in wintertime storm track regions and >6 times 10 m power in stable regimes east of continents. These results are relatively insensitive to methodology as wind power calculated using a fitted Weibull probability density function is within 10% of power calculated from discrete wind speed measurements over most of the global oceans.
Physiological responses of red mangroves to the climate in the Florida Everglades
Authors: Barr Jordan G. , Fuentes Jose D. , Engel Vic , Zieman Joseph C.
Published: April 2009

This manuscript reports the findings of physiological studies of red mangrove (Rhizophora mangle L.) conducted from June to August 2001 and from May to June 2003 in the Florida Everglades. In situ physiological measurements were made using environmentally controlled gas exchange systems. The field investigations were carried out to define how regional climate constrains mangrove physiology and ecosystem carbon assimilation. In addition, maximum carboxylation and photosynthetic active radiation (PAR) limited carbon assimilation capacities were investigated during the summer season to evaluate whether ecophysiological models developed for mesophyte plant species can be applied to mangroves. Under summertime conditions in the Florida Everglades, maximum foliar carbon dioxide (CO2) assimilation rates reached 18μmol CO2m−2s−1. Peak molar stomatal conductance to water vapor (H2O) diffusion reached 300 mmol H2O m−2s−1. Maximum carboxylation and PAR‐limited carbon assimilation rates at the foliage temperature of 30°C attained 76.1 ± 23.4μmol CO2m−2s−1and 128.1 ± 32.9μmol (e−) m−2s−1, respectively. Environmental stressors such as the presence of hypersaline conditions and high solar irradiance loading (>500 W m−2or >1000μmoles of photons m−2s−1of PAR) imposed sharp reductions in carbon assimilation rates and suppressed stomatal conductance. On the basis of both field observations and model analyses, it is also concluded that existing ecophysiological models need to be modified to consider the influences of hypersaline and high radiational loadings on the physiological responses of red mangroves.
Variability of surface water characteristics and Heinrich‐like events in the Pleistocene midlatitude North Atlantic Ocean: Biomarker and XRD records from IODP Site U1313 (MIS 16–9)
Authors: Stein Ruediger , Hefter Jens , Grützner Jens , Voelker Antje , Naafs B. David A.
Published: April 2009

A reconstruction of Milankovitch to millennial‐scale variability of sea surface temperature (SST) and sea surface productivity in the Pleistocene midlatitude North Atlantic Ocean (marine isotope stage (MIS) 16–9) and its relationship to ice sheet instability was carried out on sediments from Integrated Ocean Drilling Program (IODP) Site U1313. This reconstruction is based on alkenone and n‐alkane concentrations, U37K′ index, total organic carbon (TOC) and carbonate contents, X‐ray diffraction data, magnetic susceptibility, and accumulation rates. Increased input of ice‐rafted debris occurred during MIS 16, 12, and 10, characterized by high concentrations of dolomite, quartz, and feldspars and elevated accumulation rates of terrigenous matter. Minimum input values of terrigenous matter, on the other hand, were determined for MIS 13 and 11. Peak values of dolomite, coinciding with quartz, plagioclase, and kalifeldspar peaks and maxima in long‐chain n‐alkanes indicative for land plants, are interpreted as Heinrich‐like events related to sudden instability of the Laurentide Ice Sheet during early and late (deglacial) phases of the glacials. The coincidence of increased TOC values with elevated absolute concentrations of alkenones suggests increased glacial productivity, probably due to a more southern position of the Polar Front. Alkenone‐based SST reached absolute maxima of about 19°C during MIS 11.3 and absolute minima of <10°C during MIS 12 and 10. Within MIS 11, prominent cooling events (MIS 11.22 and 11.24) occurred. The absolute SST minima recorded directly before and after the glacial maxima MIS 10.2 and 12.2 are related to Heinrich‐like event meltwater pulses, as supported by the coincidence of SST minima and maxima in C37:4 alkenones and dolomite. These sudden meltwater pulses, especially during terminations IV and V, probably caused a collapse of phytoplankton productivity as indicated by the distinct drop in alkenone concentrations. Ice sheet disintegration and subsequent surges and outbursts of icebergs and meltwater discharge may have been triggered by increased insolation in the northern high latitudes.
East Siberian Shelf Study Alleviates Scarcity of Observations
Authors: Stemiletov Igor , Gustafsson Örjan
Published: April 2009

The East Siberian Arctic Shelf (ESAS) is the world's largest continental shelf and also the most understudied part of the Arctic Ocean. Composed of the Laptev Sea, the East Siberian Sea, and the Russian section of the Chukchi Sea, the ESAS is characterized by tundra discharge through the Lena, Indigirka, and Kolyma rivers; coastal erosion; methane seeps from subsea permafrost reservoirs; and the formation of water masses that spread throughout the Arctic Ocean.
International Symposium on the Application of Climate Information: Climate Research Applications: Innovations With Society; Tokyo, Japan, 28 January 2009
Authors: Yamagata Toshio , Behera Swadhin
Published: April 2009

The world's attention has turned to the increasing threat of anthropogenic global warming. While long‐term planning is needed to develop resilience against this threat, there is an immediate need to develop mitigation measures against extreme climate events related to natural climate variations under the stress of global warming. For decades, climate scientists have associated weather disasters mostly with the El Niño—Southern Oscillation (ENSO). However, another such phenomenon, the Indian Ocean Dipole (IOD), was identified in 1999. During the 2006 positive IOD event, more than 1 million people in East Africa were affected by heavy rains and prolonged floods, while Australia suffered one of its worst droughts. Consecutive positive IOD events in 2006, 2007, and 2008 caused the serious “Big Dry” in southeastern Australia that prepared the background for the “Black Saturday” forest fires there in February 2009.
Separation of atmosphere‐ocean‐vegetation feedbacks and synergies for mid‐Holocene climate
Authors: Otto J. , Raddatz T. , Claussen M. , Brovkin V. , Gayler V.
Published: April 2009

We determine both the impact of atmosphere‐ocean and atmosphere‐vegetation feedback, and their synergy on northern latitude climate in response to the orbitally‐induced changes in mid‐Holocene insolation. For this purpose, we present results of eight simulations using the general circulation model ECHAM5‐MPIOM including the land surface scheme JSBACH with a dynamic vegetation module. The experimental set‐up allows us to apply a factor‐separation technique to isolate the contribution of dynamic Earth system components (atmosphere, atmosphere‐ocean, atmosphere‐vegetation, atmosphere‐ocean‐vegetation) to the total climate change signal. Moreover, in order to keep the definition of seasons consistent with insolation forcing, we define the seasons on an astronomical basis. Our results reveal that north of 40°N atmosphere‐vegetation feedback (maximum in spring of 0.08°C) and synergistic effects (maximum in winter of 0.25°C) are weaker than in previous studies. The most important modification of the orbital forcing is related to the atmosphere‐ocean component (maximum in autumn of 0.78°C).
The genome sequence of the psychrophilic archaeon,Methanococcoides burtonii: the role of genome evolution in cold adaptation
Authors: Allen Michelle A , Lauro Federico M , Williams Timothy J , Burg Dominic , Siddiqui Khawar S , De Francisci Davide , Chong Kevin WY , Pilak Oliver , Chew Hwee H , De Maere Matthew Z , Ting Lily , Katrib Marilyn , Ng Charmaine , Sowers Kevin R , Galperin Michael Y , Anderson Iain J , Ivanova Natalia , Dalin Eileen , Martinez Michele , Lapidus Alla , Hauser Loren , Land Miriam , Thomas Torsten , Cavicchioli Ricardo
Published: April 2009

Psychrophilic archaea are abundant and perform critical roles throughout the Earth's expansive cold biosphere. Here we report the first complete genome sequence for a psychrophilic methanogenic archaeon, Methanococcoides burtonii. The genome sequence was manually annotated including the use of a five-tiered evidence rating (ER) system that ranked annotations from ER1 (gene product experimentally characterized from the parent organism) to ER5 (hypothetical gene product) to provide a rapid means of assessing the certainty of gene function predictions. The genome is characterized by a higher level of aberrant sequence composition (51%) than any other archaeon. In comparison to hyper/thermophilic archaea, which are subject to selection of synonymous codon usage, M. burtonii has evolved cold adaptation through a genomic capacity to accommodate highly skewed amino-acid content, while retaining codon usage in common with its mesophilic Methanosarcina cousins. Polysaccharide biosynthesis genes comprise at least 3.3% of protein coding genes in the genome, and Cell wall, membrane, envelope biogenesis COG genes are overrepresented. Likewise, signal transduction (COG category T) genes are overrepresented and M. burtonii has a high ‘IQ’ (a measure of adaptive potential) compared to many methanogens. Numerous genes in these two overrepresented COG categories appear to have been acquired from ɛ- and δ-Proteobacteria, as do specific genes involved in central metabolism such as a novel B form of aconitase. Transposases also distinguish M. burtonii from other archaea, and their genomic characteristics indicate they have an important role in evolving the M. burtonii genome. Our study reveals a capacity for this model psychrophile to evolve through genome plasticity (including nucleotide skew, horizontal gene transfer and transposase activity) that enables adaptation to the cold, and to the biological and physical changes that have occurred over the last several thousand years as it adapted from a marine to an Antarctic lake environment.
Psychosocial Stress and 13‐year BMI Change Among Blacks: The Pitt County Study
Authors: Fowler‐Brown Angela G. , Bennett Gary G. , Goodman Melody S. , Wee Christina C. , Corbie‐Smith Giselle M. , James Sherman A.
Published: April 2009

Adverse psychosocial exposures may partially drive the high rates of obesity among blacks. The objective of this study was to prospectively examine the relationship between perceived psychosocial stress and percent change in BMI among adult black men and women. We used data from 756 women and 416 men who were participants in the Pitt County Study, a community‐based, prospective cohort study of blacks in eastern North Carolina. Participants were aged 25–50 years of age on entry into the study in 1988 and follow‐up was obtained in 2001. Using multivariable linear regression, we calculated the adjusted mean percentage change in BMI over the follow‐up period for each tertile of baseline measures of the Perceived Stress Scale (low, medium, and high), adjusted for potential confounders. For black women, higher levels of psychosocial stress at baseline predicted higher adjusted percentage increase in BMI over the 13‐year follow‐up: low stress 12.0% (95% CI 9.6–14.4), medium stress 16.3% (95% CI 13.7–18.9), and high stress 15.5% (95% CI 13.1–17.8). For black men, perceived stress was not associated with percent BMI change. These data suggest that interventions targeting obesity in black women should consider the potential impact of emotional stress on weight change.
Sustained Attention in Children With Specific Language Impairment (SLI)
Authors: Finneran Denise A. , Francis Alexander L. , Leonard Laurence B.
Published: April 2009

Purpose

Information-processing limitations have been associated with language problems in children with specific language impairment (SLI). These processing limitations may be associated with limitations in attentional capacity, even in the absence of clinically significant attention deficits. In this study, the authors examined the performance of 4- to 6-year-old children with SLI and their typically developing (TD) peers on a visual sustained attention task. It was predicted that the children with SLI would demonstrate lower levels of performance in the absence of clinically significant attention deficits.

Method

A visual continuous performance task (CPT) was used to assess sustained attention in 13 children with SLI (
M =
62.07 months) and 13 TD age-matched controls (
M
= 62.92 months). All children were screened for normal vision, hearing, and attention. Accuracy (
d'
) and response time were analyzed to see if this sustained attention task could differentiate between the 2 groups.

Results

The children with SLI were significantly less accurate but not significantly slower than the TD children on this test of visual sustained attention.

Conclusion

Children with SLI may have reduced capacity for sustained attention in the absence of clinically significant attention deficits that, over time, could contribute to language learning difficulties.
What Influences Literacy Outcome in Children With Speech Sound Disorder?
Authors: Peterson Robin L. , Pennington Bruce F. , Shriberg Lawrence D. , Boada Richard
Published: April 2009

Purpose

In this study, the authors evaluated literacy outcome in children with histories of speech sound disorder (SSD) who were characterized along 2 dimensions: broader language function and persistence of SSD. In previous studies, authors have demonstrated that each dimension relates to literacy but have not disentangled their effects.

Methods

Two groups of children (86 SSD and 37 controls) were recruited at ages 5–6 and were followed longitudinally. The authors report the literacy of children with SSD at ages 7–9, compared with controls and national norms, and relative to language skill and SSD persistence (both measured at age 5–6).

Results

The SSD group demonstrated elevated rates of reading disability. Language skill but not SSD persistence predicted later literacy. However, SSD persistence was associated with phonological awareness impairments. Phonological awareness alone predicted literacy outcome less well than a model that also included syntax and nonverbal IQ.

Conclusions

Results support previous literature findings that SSD history predicts literacy difficulties and that the association is strongest for SSD + language impairment (LI). Magnitude of phonological impairment alone did not determine literacy outcome, as predicted by the core phonological deficit hypothesis. Instead, consistent with a multiple deficit approach, phonological deficits appeared to interact with other cognitive factors in literacy development.
On the Sensitivity and Specificity of Nonword Repetition and Sentence Recall to Language and Memory Impairments in Children
Authors: Archibald Lisa M. D. , Joanisse Marc F.
Published: April 2009

Purpose

The present study examined the utility of 2 measures proposed as markers of specific language impairment (SLI) in identifying specific impairments in language or working memory in school-age children.

Method

A group of 400 school-age children completed a 5-min screening consisting of nonword repetition and sentence recall. A subset of low (
n
= 52) and average (
n
= 38) scorers completed standardized tests of language, short-term and working memory, and nonverbal intelligence.

Results

Approximately equal numbers of children were identified with specific impairments in either language or working memory. A group about twice as large had deficits in both language and working memory. Sensitivity of the screening measure for both SLI and specific working memory impairments was 84% or greater, although specificity was closer to 50%. Sentence recall performance below the 10th percentile was associated with sensitivity and specificity values above 80% for SLI.

Conclusions

Developmental deficits may be specific to language or working memory, or include impairments in both areas. Sentence recall is a useful clinical marker of SLI and combined language and working memory impairments.
A dynamic global-coefficient subgrid-scale model for large-eddy simulation of turbulent scalar transport in complex geometries
Authors: You Donghyun , Moin Parviz
Published: April 2009

The dynamic global-coefficient subgrid-scale eddy-viscosity model by You and Moin [Phys. Fluids 19, 065110 (2007)] is generalized for large-eddy simulation of turbulent flow with scalar transport. The model coefficient for subgrid-scale scalar flux which is constant in space but varies in time is dynamically determined based on the “global conservation” of the transport equation for scalar variance. Large-eddy simulations of turbulent flow with passive scalar transport through a channel and over a backward-facing step show that the present model has a similar predictive capability as the dynamic Smagorinsky model. The present dynamic model is especially suitable for large-eddy simulation of turbulent flow with scalar transport in complex geometries since it does not require any spatial and temporal averaging or clipping of the model coefficient for numerical stabilization and requires only a single-level test filter. The present model is not more complicated in implementation and not more expensive in terms of computational cost than the dynamic Smagorinsky model.
A novel method for preparing stoichiometric SnO2 thin films at low temperature
Authors: Ansari S. G. , Dar M. A. , Dhage M. S. , Kim Young Soon , Ansari Z. A. , Al-Hajry A. , Shin Hyung-Shik
Published: April 2009

Tin oxide is a well known nonstoichiometric material with dual valency. The invariance of stoichiometry is very intriguing. As of today no report is available for preparing perfect stoichiometric tin oxide. Here we report a novel method to prepare stoichiometric tin oxide by modifying the known plasma enhanced chemical vapor deposition technique using SnCl4-xH2O as precursor and O2 as reactant gas at various temperatures from 300 to 800 °C. Tetragonal rutile structure of SnO2 was found, grown along the [110] direction. X-ray photoelectron spectroscopic measurement showed constant Sn/O ratio. Sn 3d and O 1s were found composed of only Sn4+ (487.2 eV) and O–Sn4+ (531.2 eV) with equal peak widths. Raman band intensity (∼633 cm−1) was found increasing with temperature, indicating the morphological changes. Sheet resistance of ∼0.5 kΩ/◻ at 300 °C was measured that reduces to ∼0.1 kΩ/◻ at 600 °C. It is found that film stoichiometry remains unaltered, while the structural morphology changes significantly.
Surface plasmon resonances of optical antenna atomic force microscope tips
Authors: Zou Yanshu , Steinvurzel Paul , Yang Tian , Crozier Kenneth B.
Published: April 2009

A method for fabricating optical antennas on atomic force microscope probes using focused ion beam modification is described. We numerically demonstrate that these optical antenna probes provide a large near field intensity enhancement when illuminated at their resonant wavelengths. We experimentally measure the plasmon resonant wavelengths of probes with various lengths. Both simulation and experiment indicate that the resonant wavelength redshifts with increasing antenna length. We anticipate that the optical antenna tips could be used for mapping the field distributions of nanophotonic devices or for high spatial resolution spectroscopy.
Relativistic dynamics of quasistable states. I. Perturbation theory for the Poincaré group
Authors: Wickramasekara S.
Published: April 2009

We propose a theory of resonances by combining the S-matrix approach with the Bakamjian–Thomas (BT) construction. Characterization of resonances by the poles of the S-matrix has many advantages. Foremost among them is perhaps the gauge invariance of the definitions of resonance mass and width, a problem with which some definitions based on field theoretical approaches suffer. The BT construction provides a general framework for constructing Poincaré generators for an interacting quantum system. While much of what we develop here can be cast in the language of quantum field theory, in the spirit of BT construction, which does not assume the existence of local field mediating interactions, we will work at the fundamental level of an interacting Poincaré algebra. Our construction shows that a subset of this Poincaré algebra integrates to a representation of the semigroup of causal transformations of relativistic space-time. These representations are characterized by the spin and S-matrix complex pole position of the resonance. The state vectors that transform under these representations also show an exact exponential decay, the signature of a decaying state. In this sense, the semigroup representations developed here tie together resonances and decaying states into a single theoretical description.
Enhanced thermal transport in carbon aerogel nanocomposites containing double-walled carbon nanotubes
Authors: Worsley Marcus A. , Satcher Joe H. , Baumann Theodore F.
Published: April 2009

We report thermal conductivity measurements of a carbon aerogel nanocomposite containing double-walled carbon nanotubes. The nanocomposites were prepared by the sol-gel polymerization of resorcinol with formaldehyde in aqueous suspension containing a surfactant-stabilized dispersion of double-walled carbon nanotubes. Subsequent drying and pyrolysis resulted in free-standing monolithic carbon aerogel nanocomposites with uniform dispersions of carbon nanotubes. The monoliths were characterized by high-resolution scanning electron microscopy and thermal conductivity measurements via the transient hot-wire method. Enhanced thermal conductivities were observed for carbon aerogel nanocomposites relative to pristine carbon aerogels. The details of these results are discussed in comparison with theory and literature.
Bubble merging in breathing DNA as a vicious walker problem in opposite potentials
Authors: Pedersen Jonas Nyvold , Hansen Mikael Sonne , Novotný Tomáš , Ambjörnsson Tobias , Metzler Ralf
Published: April 2009

We investigate the coalescence of two DNA bubbles initially located at weak domains and separated by a more stable barrier region in a designed construct of double-stranded DNA. In a continuum Fokker–Planck approach, the characteristic time for bubble coalescence and the corresponding distribution are derived, as well as the distribution of coalescence positions along the barrier. Below the melting temperature, we find a Kramers-type barrier crossing behavior, while at high temperatures, the bubble corners perform drift diffusion toward coalescence. In the calculations, we map the bubble dynamics on the problem of two vicious walkers in opposite potentials. We also present a discrete master equation approach to the bubble coalescence problem. Numerical evaluation and stochastic simulation of the master equation show excellent agreement with the results from the continuum approach. Given that the coalesced state is thermodynamically stabilized against a state where only one or a few of the base pairs of the barrier region are re-established, it appears likely that this type of setup could be useful for the quantitative investigation of thermodynamic DNA stability data as well as the rate constants involved in the unzipping and zipping dynamics of DNA in single molecule fluorescence experiments.
Fast imaging of transients and coherent magnetohydrodynamic modes in DIII-D
Authors: Yu J. H. , Van Zeeland M. A. , Chu M. S. , Izzo V. A. , La Haye R. J.
Published: April 2009

A fast framing camera is used to image plasma waves and instabilities in the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] in unprecedented detail including tearing modes (TMs) and sawtooth crashes. To image core magnetohydrodynamic (MHD) activity, the fast camera detects visible bremsstrahlung emission εB in moderate to high density plasmas. For coherent MHD activity such as TMs, high-resolution two-dimensional images of mode amplitude and phase are obtained by Fourier filtering each pixel’s time series at the mode frequency. Images of m/n=2/1 TMs show that inside the q=2 surface, the camera measurements are in excellent agreement with an analytic model of a 2/1 island superimposed on the equilibrium εB profile. Direct comparison of the measurements to a NIMROD simulation shows significant discrepancies, most likely due to artificially high-density diffusion used in the code for numerical stability. The first visible-light images of transient sawtooth crashes show the structure and location of the perturbed emission from an m=1 precursor oscillation and show that during the nonlinear crash phase the instability extends to more than half of the plasma minor radius.
Moments of ratios of characteristic polynomials of a certain class of random matrices
Authors: Wei Yi
Published: April 2009

We derive a new method of calculating the mean negative moments and ratios of squared modulus of characteristic polynomials of a certain class of random matrices. New results obtained with this method are presented.
Structural evolution and graphitization of metallorganic-Pt suspended nanowires under high-current-density electrical test
Authors: Gazzadi Gian Carlo , Frabboni Stefano
Published: April 2009

We present a real-time investigation of the dramatic structural evolution occurring in metallorganic-Pt suspended nanowires (SNWs) (20 nm size) under high-current-density electrical test. SNWs are fabricated by electron beam-induced deposition and consist of Pt nanograins (2–3 nm) embedded in a carbonaceous matrix. As current increases, the Pt–C granular material transforms into Pt-depleted, graphitized C with a two-stage process. First, Pt coalescence into big grains (10–15 nm) is observed, then, for current density approaching 107 A/cm2, grains are depleted by Pt electro- and thermomigration, leaving a graphitized C matrix. The graphitic-C wire eventually breaks forming a nanosize gap.
Nonergodic activated kinetics in polar media
Authors: Matyushov Dmitry V.
Published: April 2009

A theoretical formulation is developed for the activated kinetics when some subset of nuclear modes of the thermal bath is slower than the reaction and ergodicity of the thermal bath is not maintained. Nonergodic free energy profiles along the reaction coordinate are constructed by using restricted canonical ensembles with the phase space available to the system found by solving a self-consistent kinetic equation. The resulting activation barrier incorporates not only thermodynamic parameters but also dynamical information from the time autocorrelation function of the solute-solvent interaction energy. The theory is applied to the reactions of solvolysis and charge transfer in polar media.
Stimulated terahertz emission due to electronic Raman scattering in silicon
Authors: Pavlov S. G. , Böttger U. , Hovenier J. N. , Abrosimov N. V. , Riemann H. , Zhukavin R. Kh. , Shastin V. N. , Redlich B. , van der Meer A. F. G. , Hübers H.-W.
Published: April 2009

Stimulated Raman emission in the terahertz frequency range (4.8–5.1 THz and 5.9–6.5 THz) has been realized by optical excitation of arsenic donor centers in silicon at low temperatures. The Stokes shift of the observed laser emission is 5.42 THz which is equal to the Raman-active donor electronic transition between the ground 1s(A1) and the excited 1s(E) arsenic states. Optical thresholds of the Raman laser are similar to those observed for other silicon donor lasers. In addition, intracenter donor lasing has been observed when pumping on the dipole-forbidden 1s(A1)→2s transition.
Nanoscale organization in piperidinium-based room temperature ionic liquids
Authors: Triolo Alessandro , Russina Olga , Fazio Barbara , Appetecchi Giovanni Battista , Carewska Maria , Passerini Stefano
Published: April 2009

Here we report on the complex nature of the phase diagram of N-alkyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide ionic liquids using several complementary techniques and on their structural order in the molten state using small-wide angle x-ray scattering. The latter study indicates that the piperidinium aliphatic alkyl chains tend to aggregate, forming alkyl domains embedded into polar regions, similar to what we recently highlighted in the case of other ionic liquids.
Analytical and numerical study on the nonequilibrium relaxation by the simplified Fokker–Planck equation
Authors: Yano Ryosuke , Suzuki Kojiro , Kuroda Hisayasu
Published: April 2009

Nonequilibrium relaxation by the simplified Fokker–Planck equation is studied by calculating the relaxation of Grad’s moments. From calculated relaxation of moments, we propose two simplified Fokker–Planck-type equations. For the quantitative validation of nonequilibrium relaxation by using the simplified Fokker–Planck-type equations, we solve a rarefied shock layer problem. To study the stronger diffusion of the distribution function than the simplified Fokker–Planck-type equation, we consider diffusion of the distribution function due to the gain term of the Boltzmann equation, because the Boltzmann equation can be described by a partial differential equation with higher-order terms than the simplified Fokker–Planck equation. The effect of the gain term of the Boltzmann equation is discussed based on comparisons with our proposed Bhatnagar–Gross–Krook equation with velocity-dependent collision frequency.
Adiabatic warm-fluid equilibrium theory of thermal charged-particle beams in alternating-gradient focusing fields
Authors: Samokhvalova Ksenia R. , Zhou Jing , Chen Chiping
Published: April 2009

An adiabatic warm-fluid equilibrium theory for a thermal charged-particle beam in an alternating-gradient focusing field is presented. Warm-fluid equilibrium equations are solved in the paraxial approximation. The theory predicts that the four-dimensional rms thermal emittance of the beam is conserved, but the two-dimensional rms thermal emittances are not constant. The rms beam envelope equations and the self-consistent Poisson equation, governing the beam density and potential distributions, are derived. Although the presented rms beam envelope equations have the same form as the previously known rms beam envelope equations, the evolution of the rms emittances in the present theory is given by analytical expressions. The density does not have the simplest elliptical symmetry, but the constant-density contours are ellipses, and the aspect ratio of the elliptical constant-density contours decreases as the density decreases along the transverse displacement from the beam axis. For high-intensity beams, the beam density profile is flat in the center of the beam and falls off rapidly within a few Debye lengths, and the rate at which the density falls is approximately isotropic in the transverse directions.