bluuebunny/crossref_metadata_2025 huggingface dataset:
Earthquake cycle deformation in the Tibetan plateau with a weak mid‐crustal layer
Authors: DeVries Phoebe M. R. , Meade Brendan J.
Published: May 2013

Geodetic observations of interseismic deformation across the Tibetan plateau contain information about both tectonic and earthquake cycle processes. Time‐variations in surface velocities between large earthquakes are sensitive to the rheological structure of the subseismogenic crust, and, in particular, the viscosity of the middle and lower crust. Here we develop a semianalytic solution for time‐dependent interseismic velocities resulting from viscoelastic stress relaxation in a localized midcrustal layer in response to forcing by a sequence of periodic earthquakes. Earthquake cycle models with a weak midcrustal layer exhibit substantially more near‐fault preseismic strain localization than do classic two‐layer models at short (<100 yr) Maxwell times. We apply both this three‐layer model and the classic two‐layer model to geodetic observations before and after the 1997 MW = 7.6 Manyi and 2001 MW = 7.8 Kokoxili strike‐slip earthquakes in Tibet to estimate the viscosity of the crust below a 20 km thick seismogenic layer. For these events, interseismic stress relaxation in a weak (viscosity ≤1018.5 Pa⋅s) and thin (height ≤20 km) midcrustal layer explains observations of both preseismic near‐fault strain localization and rapid (>50 mm/yr) postseismic velocities in the years following the coseismic ruptures. We suggest that earthquake cycle models with a localized midcrustal layer can simultaneously explain both preseismic and postseismic geodetic observations with a single Maxwell viscosity, while the classic two‐layer model requires a rheology with multiple relaxation time scales.
Using environmental tracers and numerical simulation to investigate regional hydrothermal basins—Norris Geyser Basin area, Yellowstone National Park, USA
Authors: Gardner W. Payton , Susong David D. , Solomon D. Kip , Heasler Henry P.
Published: May 2013

Heat and fluid flow fields are simulated for several conceptual permeability fields and compared to processes inferred from environmental tracers in springs around Norris Geyser Basin, Yellowstone National Park. Large hydrothermal basins require specific permeability distributions in the upper crust. High permeability connections must exist between the land surface and high‐temperature environments at depths of up to 5 km. The highest modeled temperatures are produced with a vertical conduit permeability of 10−15m2. Permeability at depths of 3–5 km must be within one order of magnitude of the near‐surface permeability and must be ≥10−16m2. Environmental tracers from springs are used to develop a plausible numerical model of the local to regional groundwater flow field for the Norris Geyser Basin area. The model simulations provide insight into the dynamics of heat and fluid flow in a large regional hydrothermal system.
Petro‐fabrics and seismic properties of blueschist and eclogite in the North Qilian suture zone, NW China: Implications for the low‐velocity upper layer in subducting slab, trench‐parallel seismic anisotropy, and eclogite detectability in the subduction zone
Authors: Cao Yi , Jung Haemyeong , Song Shuguang
Published: May 2013

The potential seismological contributions of metamorphosed and deformed oceanic crust in a subduction zone environment were studied in a detailed petro‐fabric analysis of blueschist and eclogite in the North Qilian suture zone, NW China. The calculated whole‐rock seismic properties based on the measured lattice preferred orientations of the constituting minerals show increasing P‐wave and S‐wave velocities and decreasing seismic anisotropies from blueschist to eclogite, mainly due to the decreasing volume proportion and deformation extent of glaucophane. The low velocity of the upper layer in the subducting oceanic crust can be explained by the existence of blueschist and foliated eclogite, which induces a 3–12% reduction in velocity compared to that induced by the surrounding mantle rocks. This low‐velocity layer may gradually disappear when blueschist and foliated eclogite are replaced by massive eclogite at a depth in excess of 60–75 km for the paleo North Qilian subduction zone. Trench‐parallel seismic anisotropy with a moderate delay time (0.1–0.3 s) can only effectively contribute to deformed blueschist and eclogite in a high‐angle (>45–60°) subducting slab, regardless of the direction of slab movement. The calculated reflection coefficients (Rc = 0.04–0.20) at the lithologic interfaces between eclogite and blueschist imply that it may be possible to detect eclogite bodies in shallow subduction channels using high‐resolution seismic reflection profiles. However, the imaging of eclogite bodies located in deep subduction zones could be challenging.
Sea‐level trends and interannual variability in the Caribbean Sea
Authors: Torres R. Ricardo , Tsimplis Michael N.
Published: May 2013

Sea‐level trends and their forcing have been investigated in the Caribbean Sea using altimetry and tide gauge time series from 19 stations. The basin average sea‐level rise is 1.7 ± 1.3 mm yr−1 for the period 1993–2010. Significant spatial variability of the trends is found. The steric variability above 800 m combined with the global isostatic adjustment explains the observed trends for the altimetry period in most of the basin. Wind forcing changes causes the trends in the southern part of the basin, modulating the sea level through changes in the ocean circulation. The longest time series (102 years) of Cristobal shows a trend of 1.9 ± 0.1 mm yr−1 insignificantly different from the global mean sea‐level rise for the twentieth century. By contrast Cartagena, a world heritage site, has a large trend (5.3 ± 0.3 mm yr−1) significantly affected by local vertical land movements. Stations dominated by the steric contribution have smaller trends (∼1.3 ± 0.2 mm yr−1). Sea‐level trends at tide gauges are not affected by atmospheric pressure changes or by the open ocean steric contribution at most stations. Decadal variability in the sea‐level trends can partly be explained by steric and wind variability. The decadal variability in the trends is not spatially coherent. Interannual sea‐level variability accounts for one third of the total sea‐level variability and can be partly explained by the influence of El Niño‐Southern Oscillation at different time and spatial scales. No correlation with the North Atlantic Oscillation is found.
The role of weekly high‐activated positive mood, context, and personality in innovative work behavior: A multilevel and interactional model
Authors: Madrid Hector P. , Patterson Malcolm G. , Birdi Kamal S. , Leiva Pedro I. , Kausel Edgar E.
Published: May 2013

This article proposed and tested a multilevel and interactional model of individual innovation in which weekly moods represent a core construct between context, personality, and innovative work behavior. Adopting the circumplex model of affect, innovative work behavior is proposed as resulting from weekly positive and high‐activated mood. Furthermore, drawing on the Big Five model of personality and cognitive appraisal theory, openness to experience and support for innovation are proposed as individual and contextual variables, respectively, which interplay in this process. Openness to experience interacts with support for innovation leading to high‐activated positive mood. Furthermore, openness interacts with these feelings leading to greater levels of innovative work behavior. Overall, the model entails a moderated mediation process where weekly high‐activated positive mood represents a crucial variable for transforming contextual and individual resources into innovative outcomes. These propositions were tested and supported using a diary methodology and multilevel structural equation modeling, on the basis of 893 observations of innovative work behavior and moods nested in 10 weekly waves of data. This information was collected from 92 individuals of diverse occupations employed in 73 distinct companies. Theoretical and practical implications are discussed. Copyright © 2013 John Wiley & Sons, Ltd.
Multiobjective Optimization for the Asset Allocation of European Nonlife Insurance Companies
Authors: Jarraya Bilel , Bouri Abdelfettah
Published: May 2013

An optimal asset allocation is crucial for nonlife insurance companies. The most previous studies focused on this topic use a mono‐objective technique optimization. This technique usually allows the maximization of shareholders' expected utility. As nonlife insurance company is a complex system, it has many stakeholders other than shareholders. So, the satisfaction of the shareholders' expected utility cannot lead usually to the satisfaction of other stakeholders' objectives. Therefore, the focus on utility maximization can be a destruction source of other objectives such as productivity, competitiveness and solvency. Our developed model integrates simulation approach with a multiobjective particle swarm optimization algorithm. This model insures an optimal asset allocation that maximizes, simultaneously, shareholders expected utility and technical efficiency of European nonlife insurance companies. The empirical application conducts a comparison between the attained results with multiobjective optimization technique and mono‐objective technique to search the optimal asset allocation for nonlife insurance companies. Our results show that the investment portfolio will be more diversified between most available investment assets. In addition, any decision maker should take account of different stakeholders' objectives. Accordingly, multiobjective optimization allows us to find the best asset allocation that maximizes simultaneously expected utility and technical efficiency of nonlife insurance companies. Copyright © 2013 John Wiley & Sons, Ltd.
Post‐optimal Analysis for Markowitz's Multicriteria Portfolio Optimization Problem
Authors: Emelichev Vladimir , Korotkov Vladimir , Nikulin Yury
Published: May 2013

We formulate a multicriteria discrete variant of well‐known Markowitz's portfolio optimization model with Savage's ordered minimax risk criteria. We constructed lower and upper bounds of the stability radius of a lexicographic optimum (portfolio) in the case of linear metric l1 in three‐dimension space of the problem parameters. Copyright © 2013 John Wiley & Sons, Ltd.
A review of the reliability and validity of OPCRIT in relation to its use for the routine clinical assessment of mental health patients
Authors: Brittain Philip J. , Stahl Daniel , Rucker James , Kawadler Jamie , Schumann Gunter
Published: May 2013

The OPCRIT program is a symptom checklist with accompanying algorithms producing operationally defined diagnoses. We undertook a review of studies which had used OPCRIT and had reported statistics concerning its reliability and validity, producing summary measures from 44 studies. The first main measure of interest was inter‐rater reliability where mean kappa values indicated that agreement between raters was “substantial” with a marginal improvement at the diagnostic (0.76) versus individual item (0.69) level. The second main measure of interest was convergent validity – the agreement between OPCRIT and clinical diagnoses. Most studies reported these figures as concordance rates suggesting mean agreement, unadjusted for chance, of 69%. Very few studies used the chance‐adjusted kappa statistic but where this was used agreement was “fair” (0.39). Agreement between OPCRIT and other research diagnoses was “moderate” (0.60). We also considered differences between the way OPCRIT has traditionally been used in research settings and the naturalistic manner in which it will be employed in the hospital ward. This review provides a summary of the reliability and validity of OPCRIT, which will be considered during the preparation for its use in the routine characterization of mental health patients in clinical settings. Copyright © 2013 John Wiley & Sons, Ltd.
3He pO2 mapping is limited by delayed‐ventilation and diffusion in chronic obstructive pulmonary disease
Authors: Marshall Helen , Parra‐Robles Juan , Deppe Martin H. , Lipson David A. , Lawson Rod , Wild Jim M.
Published: May 2013

Purpose

Lung pO2 mapping with 3He MRI assumes that the sources of signal decay with time during a breath‐hold are radiofrequency depolarization and oxygen‐dependent T1 relaxation, but the method is sensitive to other sources of spatio‐temporal signal change such as diffusion. The purpose of this work was to assess the use of 3He pO2 mapping in patients with chronic obstructive pulmonary disease.

Methods

Ten patients with moderate to severe chronic obstructive pulmonary disease were scanned with a 3D single breath‐hold pO2 mapping sequence.

Results

Images showed signal increasing over time in some lung regions due to delayed ventilation during breath‐hold. Regions of physically unrealistic negative pO2 values were seen in all patients, and regional mean pO2 values of −0.3 bar were measured in the two patients most affected by delayed ventilation (where mean time to signal onset was 3–4 s).

Conclusions

Movement of gas within the lungs during breath‐hold causes regional changes in signal over time that are not related to oxygen concentration, leading to erroneous pO2 measurements using the linear oxygen‐dependent signal decay model. These spatio‐temporal sources of signal change cannot be reliably separated at present, making pO2 mapping using this methodology unreliable in chronic obstructive pulmonary disease patients with significant bullous emphysema or delayed ventilation. Magn Reson Med 71:1172–1178, 2014. © 2013 Wiley Periodicals, Inc.
APT‐weighted and NOE‐weighted image contrasts in glioma with different RF saturation powers based on magnetization transfer ratio asymmetry analyses
Authors: Zhou Jinyuan , Hong Xiaohua , Zhao Xuna , Gao Jia‐Hong , Yuan Jing
Published: May 2013

Purpose

To investigate the saturation‐power dependence of amide proton transfer (APT)‐weighted and nuclear Overhauser enhancement‐weighted image contrasts in a rat glioma model at 4.7 T.

Methods

The 9L tumor‐bearing rats (n = 8) and fresh chicken eggs (n = 4) were scanned on a 4.7‐T animal magnetic resonance imaging scanner. Z‐spectra over an offset range of ±6 ppm were acquired with different saturation powers, followed by the magnetization transfer‐ratio asymmetry analyses around the water resonance.

Results

The nuclear Overhauser enhancement signal upfield from the water resonance (−2.5 to −5 ppm) was clearly visible at lower saturation powers (e.g., 0.6 µT) and was larger in the contralateral normal brain tissue than in the tumor. Conversely, the APT effect downfield from the water resonance was maximized at relatively higher saturation powers (e.g., 2.1 µT) and was larger in the tumor than in the contralateral normal brain tissue. The nuclear Overhauser enhancement decreased the APT‐weighted image signal, based on the magnetization transfer‐ratio asymmetry analysis, but increased the APT‐weighted image contrast between the tumor and contralateral normal brain tissue.

Conclusion

The APT and nuclear Overhauser enhancement image signals in tumor are maximized at different saturation powers. The saturation power of roughly 2 μT is ideal for APT‐weighted imaging at clinical B0 field strengths. Magn Reson Med 70:320–327, 2013. © 2013 Wiley Periodicals, Inc.
Simulation of drilling‐induced compaction bands using discrete element method
Authors: Rahmati H. , Nouri A. , Chan D. , Vaziri H.
Published: May 2013

Rock failure is observed around boreholes often with certain types of failure zones, which are called breakouts. Laboratory‐scale drilling tests in some high‐porosity quartz‐rich sandstone have shown breakouts in the form of narrow localized compacted zones in the minimum horizontal stress direction. They are called fracture‐like breakouts. Such compaction bands may affect hydrocarbon extraction by forming barriers that inhibit fluid flow and may also be a source of sand production.

This paper presents the results of numerical simulations of borehole breakouts using 3D discrete element method to investigate the mechanism of the fracture‐like breakouts and to identify the role of far‐field stresses on the breakout dimensions. The numerical tool was first verified against analytical solutions. It was then utilized to investigate the failure mechanism and breakout geometry for drilled cubic rock samples of Castlegate sandstone subjected to different pre‐existing far‐field stresses.

Results show that failure occurs in the zones of the highest concentration of tangential stress around the borehole. It is concluded that fracture‐like breakout develops as a result of a nondilatant failure mechanism consisting of localized grain debonding and repacking and grain crushing that lead to the formation of a compaction band in the minimum horizontal stress direction. In addition, it is found that the length of fracture‐like breakouts depends on both the mean stress and stress anisotropy. However, the width of the breakout is not significantly changed by the far‐field stresses. Copyright © 2013 John Wiley & Sons, Ltd.
Identification of recurrent FGFR3 fusion genes in lung cancer through kinome‐centred RNA sequencing
Authors: Majewski Ian J , Mittempergher Lorenza , Davidson Nadia M , Bosma Astrid , Willems Stefan M , Horlings Hugo M , de Rink Iris , Greger Liliana , Hooijer Gerrit KJ , Peters Dennis , Nederlof Petra M , Hofland Ingrid , de Jong Jeroen , Wesseling Jelle , Kluin Roelof JC , Brugman Wim , Kerkhoven Ron , Nieboer Frank , Roepman Paul , Broeks Annegien , Muley Thomas R , Jassem Jacek , Niklinski Jacek , van Zandwijk Nico , Brazma Alvis , Oshlack Alicia , van den Heuvel Michel , Bernards René
Published: May 2013

Oncogenic fusion genes that involve kinases have proven to be effective targets for therapy in a wide range of cancers. Unfortunately, the diagnostic approaches required to identify these events are struggling to keep pace with the diverse array of genetic alterations that occur in cancer. Diagnostic screening in solid tumours is particularly challenging, as many fusion genes occur with a low frequency. To overcome these limitations, we developed a capture enrichment strategy to enable high‐throughput transcript sequencing of the human kinome. This approach provides a global overview of kinase fusion events, irrespective of the identity of the fusion partner. To demonstrate the utility of this system, we profiled 100 non‐small cell lung cancers and identified numerous genetic alterations impacting fibroblast growth factor receptor 3 (FGFR3) in lung squamous cell carcinoma and a novel ALK fusion partner in lung adenocarcinoma. © 2013 The Authors. Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
Spatial variation in herbicide leaching from a marine clay soil via subsurface drains
Authors: Ulén Barbro M , Larsbo Mats , Kreuger Jenny K , Svanbäck Annika
Published: May 2013

Background

Subsurface transport via tile drains can significantly contribute to pesticide contamination of surface waters. The spatial variation in subsurface leaching of normally applied herbicides was examined together with phosphorus losses in 24 experimental plots with water sampled flow‐proportionally. The study site was a flat, tile‐drained area with 60% marine clay in the topsoil in southeast Sweden. The objectives were to quantify the leaching of frequently used herbicides from a tile drained cracking clay soil and to evaluate the variation in leaching within the experimental area and relate this to topsoil management practices (tillage method and structure liming).

Results

In summer 2009, 0.14, 0.22 and 1.62%, respectively, of simultaneously applied amounts of MCPA, fluroxypyr and clopyralid were leached by heavy rain five days after spraying. In summer 2011, on average 0.70% of applied bentazone was leached by short bursts of intensive rain 12 days after application. Peak flow concentrations for 50% of the treated area for MCPA and 33% for bentazone exceeded the Swedish no‐effect guideline values for aquatic ecosystems. Approximately 0.08% of the glyphosate applied was leached in dissolved form in the winters of 2008/2009 and 2010/2011. Based on measurements of glyphosate in particulate form, total glyphosate losses were twice as high (0.16%) in the second winter. The spatial inter‐plot variation was large (72–115%) for all five herbicides studied, despite small variations (25%) in water discharge.

Conclusions

The study shows the importance of local scale soil transport properties for herbicide leaching in cracking clay soils. © 2013 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
A flexible QoS architecture for DVB‐RCS2
Authors: Fairhurst Gorry , Secchi Raffaello , Yun Ana
Published: May 2013

This paper presents a QoS, architecture for the Higher Layers Satellite in the second generation Digital Video Broadcasting with Return Channel via Satellite standard. It describes the flexibility offered by integrating link and network functions to support internet protocol‐based differentiated QoS. The operation of key mechanisms is outlined and analysed to show how these may be combined to realise differentiated services by defining mappings between per‐hop behaviours, to queues in the traffic plane and return channel satellite terminal request classes in the control plane. Simulation is used to show that an appropriate mapping can be used to can tune the offered service to different traffic classes and that an appropriate assignment can significantly improve the satellite bandwidth efficiency and/or the performance/QoS supplied to a traffic class. Copyright © 2013 John Wiley & Sons, Ltd.
Effect of microstructure on the corrosion behaviour of extruded heat exchanger aluminium alloys
Authors: Laferrere A. , Parson N. , Zhou X. , Thompson G.
Published: May 2013

Aluminium extrusions used for heat transfer applications are exposed to corrosive environments, which can eventually lead to perforation of the tube by pitting. In this study, the effect of microstructure on the corrosion behaviour of extruded AA3XXX series alloys has been investigated. It was revealed that pits developed were purely crystallographic and a drop testing procedure was developed to simulate the seawater acetic acid test in a laboratory environment. The drop testing experiment has been successfully employed to study the early stages of pitting for different surface finishes. Selected pits were studied with in‐SEM nanotomography. Stable pits initiated on areas free of second‐phase particles, in the vicinity of grain boundaries. When the corrosion front reached a grain boundary plane, pit propagation was interrupted in the direction perpendicular to the plane and the corrosion front followed grain boundaries, corroding one grain body more than its neighbour. A mechanistic understanding of crystallographic pitting corrosion has been developed. Copyright © 2013 John Wiley & Sons, Ltd.
Urban transport and CO2 emissions: some evidence from Chinese cities
Authors: Darido Georges , Torres‐Montoya Mariana , Mehndiratta Shomik
Published: May 2013

The work presented below was conducted as part of the World Bank's economic and sector work titled ‘Urban Transport and Climate Change’. It is first a compendium of data—most of it collected as part of the ‘China–GEF–World Bank Urban Transport Partnership Program’—and also provides a preliminary analysis of urban transport characteristics, energy use, and greenhouse gas (GHG) emissions for a diverse set of cities in China. This working paper is not in itself intended to be a strategy for urban transport and climate change in China. It is the view of the authors that this research could be an input toward the development of such a strategy in China and more broadly. Although transport in general, and urban transport in particular, is acknowledged to be an important and growing source of GHG emissions, work still needs to be done to develop robust and standardized datasets and frameworks to support a decision‐making process. The paper is intended as a background document to support ongoing discussions about a climate change strategy and to establish a dataset to be made available as a platform for future studies and further refinement. It is hoped that others will take advantage of the dataset created for this study and use it as a basis for projections, comparative analysis, and to test their own hypothesis. Reviewers of this paper have also raised many specific possibilities and interesting ideas for further work, which are summarized in the conclusions. The authors would particularly like to thank AusAID (the Australian Government's overseas aid program), ESMAP (Energy Sector Management Assistance Program), and GEF (Global Environment Facility) who provided partial financing for this work. The authors would also like to acknowledge the management of the World Bank's Sustainable Development units in East Asia & Pacific Region and Latin American & the Caribbean Region for their support.

This article is categorized under:

Energy Efficiency > Systems and Infrastructure

Energy Infrastructure > Systems and Infrastructure

Energy and Climate > Systems and Infrastructure
Determination of low-energy constants of Wilson chiral perturbation theory
Authors: Herdoíza Gregorio , Jansen Karl , Michael Chris , Ottnad Konstantin , Urbach Carsten ,   The ETM collaboration
Published: May 2013

Abstract

By matching Wilson twisted mass lattice QCD determinations of pseudoscalar meson masses to Wilson Chiral Perturbation Theory we determine the low-energy constants
$ W_6^{\prime } $
,
$ W_8^{\prime } $
and their linear combination c
2. We explore the dependence of these low-energy constants on the choice of the lattice action and on the number of dynamical flavours.
Understanding pancreatic cancer genomes
Authors: Cowley Mark J. , Chang David K. , Pajic Marina , Johns Amber L. , Waddell Nicola , Grimmond Sean M. , Biankin Andrew V.
Published: May 2013

Pancreatic cancer is the fourth leading cause of cancer death in our society, with a mortality that virtually parallels its incidence, a median survival of <12 months even with maximal therapy, and a 5‐year survival rate of <5 %. The diversity of clinical outcomes and the molecular heterogeneity of histopathologically similar cancer types, incomplete knowledge of the genomic aberrations that drive carcinogenesis and the lack of therapeutics that specifically target most known genomic aberrations necessitates large‐scale detailed analysis of cancer genomes to identify novel potential therapeutic strategies. As part of the International Cancer Genome Consortium (ICGC), the Australian Pancreatic Cancer Genome Initiative (APGI) used exomic sequencing and copy number analysis to define genomic aberrations that characterize a large, clinically focused, prospectively accrued cohort of patients with pancreatic cancer. The cohort consisted of early (clinical stages I and II) non‐pre‐treated patients with pancreatic ductal adenocarcinoma who underwent operative resection with curative intent. We devised approaches to adjust for low epithelial content in primary tumours and to define the genomic landscape of pancreatic cancer to identify novel candidate driver genes and mechanisms. We aim to develop stratified, molecular phenotype‐guided therapeutic strategies using existing therapeutics that are either rescued, repurposed, in development, or are known to be effective in an undefined subgroup of PC patients. These are then tested in primary patient‐derived xenografts and cell lines from the above deeply characterized cohort. In addition, we return information to treating clinicians that influences patient care and are launching a clinical trial called IMPaCT (Individualized Molecular Pancreatic Cancer Therapy). This umbrella design trial randomizes patients with metastatic disease to either standard first‐line therapy with gemcitabine, or a molecular phenotype‐guided approach using next‐generation sequencing strategies to screen for actionable mutations defined through the ICGC effort.
Primate abundance and habitat preferences on the lower Urubamba and Tambo rivers, central–eastern Peruvian Amazonia
Authors: Aquino Rolando , Cornejo Fanny M. , Heymann Eckhard W.
Published: May 2013

We report information on population density, group size, and habitat preferences of primates along the lower Río Urubamba and in the Río Urubamba–Río Tambo interfluvium, in central–eastern Peruvian Amazonia, an area that has been little explored with regard to its primate fauna. During 425 km of transect walks in October–November 2008 and April–May 2009 totally 174 groups of nine primate species were encountered, the most common beingCallicebus brunneus(45 groups),Saguinus imperator(41 groups), andAotus nigriceps(26 groups). Group sizes were smallest forA. nigricepsandC. brunneus(mean of 2.8 and 2.9, respectively) and largest forSaimiri boliviensis(mean 15.6). Population densities were lowest forLagothrix cana(3.3 individuals/km2) and highest forA. nigriceps(31.1 individuals/km2). Groups ofC. brunneus,S. imperator,S. boliviensis,Cebus albifrons, andCebus apellawere most frequently (83 % of sightings) encountered in semi-dense or in open primary forest that included stands of bamboo (Guadua sarcocarpa) or where bamboo was a very common species.
Retracted: Novel Imidazolium‐Based Gemini Surfactants: Synthesis, Surface Properties, Corrosion Inhibition and Biocidal Activity Against Sulfate‐Reducing Bacteria
Authors: Aiad Ismail , Emam Dalia , El‐Deeb Ali , Abd‐Alrahman Eman
Published: May 2013

Three novel imidazolium‐based gemini surfactants had been synthesized and characterized using different spectroscopic techniques. The surface properties of the synthesized surfactants were determined using surface tension measurements at 20 °C. The surface parameters including critical micelle concentration (CMC), πCMC, Pc20, Γmax and Amin were determined. The synthesized compounds were evaluated as corrosion inhibitors for carbon steel in 0.5 M HCl solution using the weight loss and polarization techniques. The biological activity of these surfactants was evaluated against sulfate reducing bacteria using most probable number method. The results indicate that the synthesized compounds have good surface properties and are proper corrosion inhibitors for low carbon steel, with a high inhibition efficiency observed around their CMC. These compounds exhibit a significant biocidal activity against sulfate reducing bacteria.
Fast prediction of deleterious angiogenin mutations causing amyotrophic lateral sclerosis
Authors: Padhi Aditya K. , Vasaikar Suhas V. , Jayaram Bhyravabhotla , Gomes James
Published: May 2013

Certain single nucleotide polymorphisms causing missense mutations in angiogenin result in its loss‐of‐function and onset of amyotrophic lateral sclerosis (ALS). Although several such associations are reported across diverse ethnic groups, no method is available for predicting if a new mutation is deleterious. We present here a fast molecular dynamics based method for determining the mechanisms of functional loss caused by mutations, and attributes to ascertain whether a mutation causes ALS.
A Review of Emergency Medical Services Events in US National Parks From 2007 to 2011
Authors: DeClerck Matthieu P. , Atterton Laurie M. , Seibert Thomas , Cushing Tracy A.
Published: May 2013

Objective

Outdoor recreation is growing in the United States, with more than 279 million annual visitors to areas controlled by the National Park Service (NPS). Emergency medical needs in these parks are overseen by the National Park's rangers within the NPS Emergency Medical Services (EMS) system. This study examines medical and traumatic emergencies throughout the NPS over a 5-year period to better understand the types of events and fatalities rangers encounter, both regionally and on a national scale.

Methods

This is a retrospective review of the annual EMS reports published by the 7 NPS regions from 2007 to 2011. The following were compared and examined at a regional and national level: medical versus traumatic versus first aid events, cardiac events and outcomes, use of automated external defibrillators, and medical versus traumatic fatalities.

Results

The national incidence of EMS events was 45.9 events per 1 million visitors. Medical, traumatic, and first aid events composed 29%, 28%, and 43% of reports, respectively. Of medical episodes, 1.8% were cardiac arrests, of which 64.2% received automated external defibrillator treatment; 29.1% of cardiac arrests survived to hospital discharge. Of fatalities, 61.4% were traumatic in nature and the remaining 38.5% were nontraumatic (medical). Regional differences were found for all variables.

Conclusions

On a national level, the NPS experiences an equal number of medical and traumatic EMS events. This differs from past observed trends that reported a higher incidence of traumatic events than medical events in wilderness settings. Cardiac events and automated external defibrillator usage are relatively infrequent. Traumatic fatalities are more common than medical fatalities in the NPS. Regional variations in events likely reflect differences in terrain, common activities, proximity to urban areas, and access to definitive care between regions. These data can assist the NPS in targeting the regions with the greatest number of incidents and fatalities for prevention, ranger training, and visitor education.
A 30,000 yr Record of land-ocean interaction in the eastern gulf of Guinea
Authors: Marret Fabienne , Kim So-Young , Scourse James
Published: May 2013

A 30,000 yr dinocyst and pollen record from the eastern equatorial Atlantic (off Cameroon) has been investigated in order to identify land–ocean linkages during the last deglacial transition. A strong correlation between the abundance of Brigantedinium spp. and the Ca/Fe ratio during the last glacial period suggests enhanced marine productivity in association with cool seawater temperatures and nutrient input linked to coastal upwelling and/or a proximal river mouth. Dry conditions are recorded on the adjacent continent with a significant representation of open vegetation indicators and the Afromontane taxon Podocarpus. After 17 calka BP these indicators register a sharp decline as a result of a climatic transition from the dry/cooler conditions of the last glacial period to the wetter/warmer conditions of the deglaciation. Simultaneously, dinocysts show a significant shift from dominant heterotrophs to an increasing abundance of autotrophs, reflecting warmer conditions. Significant changes are observed during the Younger Dryas, with a return to drier conditions and higher salinities. The start of the Holocene is marked by very low-salinity conditions, reflecting optimal monsoonal conditions over west equatorial Africa. The end of the African Humid Period is observed between 6 and 5 calka BP, followed by significant fluctuations in both terrestrial and oceanic proxies.
The quasi-geostrophic theory of the thermal shallow water equations
Authors: Warneford Emma S. , Dellar Paul J.
Published: May 2013

The thermal shallow water equations provide a depth-averaged description of motions in a fluid layer that permits horizontal variations in material properties. They typically arise through an equivalent barotropic approximation of a two-layer system, with a spatially varying density contrast due to an evolving temperature field in the active layer. We formalize a previous derivation of the quasi-geostrophic (QG) theory of these equations, by performing a direct asymptotic expansion for small Rossby number. We then present a second derivation as the small Rossby number limit of a balanced model that projects out high-frequency dynamics due to inertia-gravity waves. This latter derivation has wider validity, not being restricted to mid-latitude$\beta $-planes. We also derive their local energy conservation equation from the QG limit of a thermal shallow water pseudo-energy conservation equation. This derivation involves the ageostrophic correction to the leading-order geostrophic velocity that is eliminated in the usual derivation of a closed evolution equation for the QG potential vorticity. Finally, we derive the non-canonical Hamiltonian structure of the thermal QG equations from a decomposition in Rossby number of a pseudo-energy and Poisson bracket for the thermal shallow water equations.
Receptivity of the boundary layer to vibrations of the wing surface
Authors: Ruban A. I. , Bernots T. , Pryce D.
Published: May 2013

In this paper we study the generation of Tollmien–Schlichting waves in the boundary layer due to elastic vibrations of the wing surface. The subsonic flow regime is considered with the Mach number outside the boundary layer $M= O(1)$. The flow is investigated based on the asymptotic analysis of the Navier–Stokes equations at large values of the Reynolds number, $\mathit{Re}= {\rho }_{\infty } {V}_{\infty } L/ {\mu }_{\infty } $. Here $L$ denotes the wing section chord; and ${V}_{\infty } $, ${\rho }_{\infty } $ and ${\mu }_{\infty } $ are the free stream velocity, air density and dynamic viscosity, respectively. We assume that in the spectrum of the wing vibrations there is a harmonic that comes in to resonance with the Tollmien–Schlichting wave on the lower branch of the stability curve; this happens when the frequency of the harmonic is a quantity of the order of $({V}_{\infty } / L){\mathit{Re}}^{1/ 4} $. The wavelength, $\ell $, of the elastic vibrations of the wing is assumed to be $\ell \sim L{\mathit{Re}}^{- 1/ 8} $, which has been found to represent a ‘distinguished limit’ in the theory. Still, the results of the analysis are applicable for $\ell \gg L{\mathit{Re}}^{- 1/ 8} $ and $\ell \ll L{\mathit{Re}}^{- 1/ 8} $; the former includes an important case when $\ell = O(L)$. We found that the vibrations of the wing surface produce pressure perturbations in the flow outside the boundary layer, which can be calculated with the help of the ‘piston theory’, which remains valid provided that the Mach number, $M$, is large as compared to ${\mathit{Re}}^{- 1/ 4} $. As the pressure perturbations penetrate into the boundary layer, a Stokes layer forms on the wing surface; its thickness is estimated as a quantity of the order of ${\mathit{Re}}^{- 5/ 8} $. When $\ell = O({\mathit{Re}}^{- 1/ 8} )$ or $\ell \gg {\mathit{Re}}^{- 1/ 8} $, the solution in the Stokes layer appears to be influenced significantly by the compressibility of the flow. The Stokes layer on its own is incapable of producing the Tollmien–Schlichting waves. The reason is that the characteristic wavelength of the perturbation field in the Stokes layer is much larger than that of the Tollmien–Schlichting wave. However, the situation changes when the Stokes layer encounters a wall roughness, which are plentiful in real aerodynamic flows. If the longitudinal extent of the roughness is a quantity of the order of ${\mathit{Re}}^{- 3/ 8} $, then efficient generation of the Tollmien–Schlichting waves becomes possible. In this paper we restrict our attention to the case when the Stokes layer interacts with an isolated roughness. The flow near the roughness is described by the triple-deck theory. The solution of the triple-deck problem can be found in an analytic form. Our main concern is with the flow behaviour downstream of the roughness and, in particular, with the amplitude of the generated Tollmien–Schlichting waves.
Multilayer shallow water equations with complete Coriolis force. Part 3. Hyperbolicity and stability under shear
Authors: Stewart Andrew L. , Dellar Paul J.
Published: May 2013

We analyse the hyperbolicity of our multilayer shallow water equations that include the complete Coriolis force due to the Earth’s rotation. Shallow water theory represents flows in which the vertical shear is concentrated into vortex sheets between layers of uniform velocity. Such configurations are subject to Kelvin–Helmholtz instabilities, with arbitrarily large growth rates for sufficiently short-wavelength disturbances. These instabilities manifest themselves through a loss of hyperbolicity in the shallow water equations, rendering them ill-posed for the solution of initial value problems. We show that, in the limit of vanishingly small density difference between the two layers, our two-layer shallow water equations remain hyperbolic when the velocity difference remains below the same threshold that also ensures the hyperbolicity of the standard shallow water equations. Direct calculation of the domain of hyperbolicity becomes much less tractable for three or more layers, so we demonstrate numerically that the threshold for the velocity differences, below which the three-layer equations remain hyperbolic, is also unchanged by the inclusion of the complete Coriolis force. In all cases, the shape of the domain of hyperbolicity, which extends outside the threshold, changes considerably. The standard shallow water equations only lose hyperbolicity due to shear parallel to the direction of wave propagation, but the complete Coriolis force introduces another mechanism for loss of hyperbolicity due to shear in the perpendicular direction. We demonstrate that this additional mechanism corresponds to the onset of a transverse shear instability driven by the non-traditional components of the Coriolis force in a three-dimensional continuously stratified fluid.
Lagrangian approach to laminar–turbulent interfaces in transitional pipe flow
Authors: Holzner Markus , Song Baofang , Avila Marc , Hof Björn
Published: May 2013

Transition in shear flows is characterized by localized turbulent regions embedded in the surrounding laminar flow. These so-called turbulent spots or puffs are observed in a variety of shear flows and in certain Reynolds-number regimes, and they are advected by the flow while keeping their characteristic length. We show here for the case of pipe flow that this seemingly passive advection of turbulent puffs involves continuous entrainment and relaminarization of laminar and turbulent fluid across strongly convoluted interfaces. Surprisingly, interface areas are almost two orders of magnitude larger than the pipe cross-section, while local entrainment velocities are much smaller than the mean speed. Even though these velocities were shown to be small and proportional to the Kolmogorov velocity scale (in agreement with a prediction by Corrsin) in a flow without mean shear before, we find that, in pipe flow, local entrainment velocities are about an order of magnitude smaller than this scale. The Lagrangian method used to study the dynamics of the laminar–turbulent interfaces allows accurate determination of the leading and trailing edge speeds. However, to resolve the highly complex interface dynamics requires much higher numerical resolutions than for ordinary turbulent flows. This method also reveals that the volume flux across the leading edge has the same radial dependence but the opposite sign as that across the trailing edge, and it is this symmetry that is responsible for the puff shape remaining constant.
Aerodynamic noise from a poroelastic edge with implications for the silent flight of owls
Authors: Jaworski Justin W. , Peake N.
Published: May 2013

The interaction of a turbulent eddy with a semi-infinite poroelastic edge is examined with respect to the effects of both elasticity and porosity on the efficiency of aerodynamic noise generation. The scattering problem is solved using the Wiener–Hopf technique to identify the scaling dependence of the resulting aerodynamic noise on plate and flow properties, including the dependence on a characteristic flow velocity$U$. Special attention is paid to the limiting cases of porous-rigid and impermeable–elastic plate conditions. Asymptotic analysis of these special cases reveals parametric limits where the far-field acoustic power scales like${U}^{6} $for a porous edge, and a new finite range of${U}^{7} $behaviour is found for an elastic edge, to be compared with the well-known${U}^{5} $dependence for a rigid impermeable edge. Further numerical results attempt to address how trailing-edge noise may be mitigated by porosity and flexibility and seek to deepen the understanding of how owls hunt in acoustic stealth.
Tracer particle momentum effects in vortex flows
Authors: Birch David M. , Martin Nicholas
Published: May 2013

The measurement of vortex flows with particle-image velocimetry (PIV) is particularly susceptible to error arising from the finite mass of the tracer particles, owing to the high velocities and accelerations typically experienced. A classical model of Stokes-flow particle transport is adopted, and an approximate solution for the case of particle transport within an axisymmetric, quasi-two-dimensional Batchelor$q$-vortex is presented. A generalized expression for the maximum particle tracking error is proposed for each of the velocity components, and the importance of finite particle size distributions is discussed. The results indicate that the tangential velocity component is significantly less sensitive to tracking error than the radial component, and that the conventional particle selection criterion (based on the particle Stokes number) may result in either over- or under-sized particles for a specified allowable error bound. Results were demonstrated by means of PIV measurements carried out in air and water using particles with very different properties.
Oral administration ofBifidobacterium longumCECT 7347 ameliorates gliadin-induced alterations in liver iron mobilisation
Authors: Laparra José Moisés , Olivares Marta , Sanz Yolanda
Published: May 2013

Coeliac disease is an autoimmune disorder triggered by gluten intake, causing intestinal inflammation and mucosal damage commonly associated with the malabsorption of nutrients and ferropenic anaemia. The present study evaluates the effects of the oral administration ofBifidobacterium longumCECT 7347 on gliadin-mediated alterations in hepatic Fe deposition and Hb concentration, liver transferrin receptor (TfR)-2, IL-6, TNF-α and hepcidin (Hamp) expression (mRNA), and active hepcidin peptide production by liquid chromatography–MS/MS. Weanling rats, sensitised or not with interferon (IFN)-γ, were fed with gliadins and/or the bifidobacterial strain. Gliadin feeding increased hepatic Fe deposition; however, only gliadin-fed sensitised animals showed lower Hb concentrations than the controls.TfR2expression decreased after gliadins were fed to both sensitised and non-sensitised animals, and restored by the administration ofB. longum. These observations were accompanied by increases inIL-6expression levels in all the treatment groups; however,TNF-αexpression only increased significantly in animals fed gliadins alone or together withB. longumif they had previously been sensitised with IFN-γ. Liver expression levels ofHampdiminished in all cases to the lowest values in animals sensitised with IFN-γ after being fed with gliadins and/or bifidobacteria. In these animals, plasmaHampactive peptide concentrations significantly increased when compared with the controls. Significant correlations were calculated betweenHampexpression and liver Fe contents (liver Fe = 1/0·0032+0·032 × Hampexp), and Hb concentrations (Hb = 11·49+10·13 × (Hampexp)1/2). These data indicate that oral administration ofB. longumameliorates gliadin-mediated perturbations in liver Fe deposition and mobilisation.