bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolomic analysis of soil communities can be used for pollution assessment
Authors: Jones Oliver A.H. , Sdepanian Stephanie , Lofts Steven , Svendsen Claus , Spurgeon David J. , Maguire Mahon L. , Griffin Julian L.
Published: October 2013

Metabolic profiling can be used to assess the changes in biochemical profiles of soil communities living in contaminated sites. The term “community metabolomics” is proposed for the application of metabolomics techniques to the study of the entire community of a soil sample. The authors anticipate the present study to be a starting point for the use of this technique to assess how communities respond to factors such as pollution and climate change. Environ Toxicol Chem 2014;33:61–64. © 2013 SETAC
On the feasibility of indoor broadband secondary access to 960–1215 MHz aeronautical spectrum
Authors: Obregon Evanny , Sung Ki Won , Zander Jens
Published: October 2013

In this paper, we analyse the feasibility of indoor broadband service provisioning using secondary spectrum access to the 960–1215 MHz band, primarily allocated to the distance measuring equipment (DME) system for aeronautical navigation. We propose a practical secondary sharing scheme customised to the characteristics of the DME. Because the primary system performs a safety‐of‐life functionality, protection from harmful interference becomes extremely critical. The proposed scheme controls aggregate interference by imposing an individual interference threshold on the secondary users. We examine the feasibility of large scale secondary access in terms of the transmission probability of the secondary users that keeps the probability of harmful interference below a given limit. Uncertainties in the estimation of propagation loss and DME location affect the feasibility of the secondary access. Numerical results show that a large number of secondary users are able to operate in adjacent DME channels without harming the primary system even with limited accuracy on the estimation of the propagation loss. Copyright © 2013 John Wiley & Sons, Ltd.
The heterogeneity of inter‐domain Internet application flows: entropic analysis and flow graph modelling
Authors: Yu Ke , Li Frank Y. , Wu Xiaofei , Di Jiaxi
Published: October 2013

The growing popularity of the Internet has triggered the proliferation of various applications, which possess diverse communication patterns and user behaviour. In this paper, the heterogeneous characteristics of Internet applications and traffic are investigated from a complex network and entropic perspective. On the basis of real‐life flow data collected from a public network provided by an Internet service provider, flow graphs are constructed for five types of applications as follows: Web, P2P Download, P2P Stream, Video Stream and Instant Messaging. Three types of entropy measures are introduced to the flow graphs, and the heterogeneity of applications within a 24‐h period is analysed and compared. By using the strict timing information of the flow records, the growth process and the entropy fluctuation of flow graphs are observed. On the basis of the analysis of the flow records, a complex network model is developed for the flow graph growth. Simulation results show that the novel model matches well the flow graphs in terms of both degree distribution and entropy dynamics. Our analysis results and the proposed model shed light on traffic identification and modelling for inter‐domain traffic in today's Internet. Copyright © 2013 John Wiley & Sons, Ltd.
Adaptive resource allocation and decoding strategy for underlay multi‐carrier cooperative cognitive radio systems
Authors: Pischella Mylene , Le Ruyet Didier
Published: October 2013

This paper proposes a resource allocation and decoding strategy at the secondary system for underlay and interweave multi‐carrier cooperative cognitive radio. The objective is to maximise the sum rate of both primary and secondary systems, taking into account the interference threshold constraint and the fact that the primary receiver always considers interference as noise. The decoding method at the secondary receivers is either Successive Interference Cancellation or treating interference as noise, depending on their channel gains. The rationale for this strategy is the extension of the Han–Kobayashi capacity‐achieving strategy on the Gaussian interference channel to the studied cognitive scenario. The proposed resource allocation algorithm is composed of a subcarrier allocation procedure to avoid intercell interference between secondary cells and of an iterative power allocation algorithm that maximises the sum rate on the primary and secondary cells, respectively. The proposed algorithm achieves high data rate improvements for the secondary systems while maintaining a low degradation on the primary system's rate. It also benefits from multi‐user diversity and is robust to the distance variations. Copyright © 2013 John Wiley & Sons, Ltd.
Novel flame‐retardant epoxy based on zinc methylethyl phosphinate
Authors: Liu Xueqing , Liu Jiyan , Sun Shan , Chen Jia , Cai Shaojun
Published: October 2013

A novel flame retardant zinc methylethylphosphinate (Zn(MEP)) was used to fill epoxy resins (EPs). The structure of Zn(MEP) was conformed with Fourier transform infrared, hydrogen nuclear magnetic resonance and phosphorus nuclear magnetic resonance, and X‐ray fluorescent and X‐ray diffraction. The flammability, decomposition behavior, and glass transition temperature (Tg) of cured EP/Zn(MEP) were investigated. Zn(MEP) is stable below 406°C. EP containing 20 phr of Zn(MEP) achieves 27.5% of limiting oxygen index and UL‐94 V0 rating. Scanning electron microscopy‐energy‐dispersive X‐ray and Fourier transform infrared spectroscopy investigations show that a condensed char layer with carbon‐rich and phosphorus‐rich components was formed during heating Zn(MEP)/EP, the atomic ratio of P to Zn on the surface of the char is reduced compared with the initial sample. The P‐rich components and lower atomic ratio of P/Zn on the char surface implies that the Zn(MEP) acts in both condensed phase and gas phase. TGA investigation shows that there are interactions between Zn(MEP) and EP when they are copyrolyzed. The interactions lead to a modification in degradation process and promote the char forming. Compared with aluminum diethylphosphinate Zn(MEP) filled EP shows lower limiting oxygen index but higher Tg. In addition, the interactions between polymer and additive are different when aluminum diethylphosphinate instead of Zn(MEP) is added into EP. Copyright © 2013 John Wiley & Sons, Ltd.
Furan resin as a replacement of phenolics: influence of the clay addition on its thermal degradation and fire behaviour
Authors: Rivero Guadalupe , Villanueva Sara , Manfredi Liliana B.
Published: October 2013

Nanocomposites based on a furan resin and different types of clays were obtained. Their thermal and fire behaviours were compared with traditional phenolic resins, which are known by their excellent flame resistance. Three types of montmorillonite clays were in situ added to the thermosetting matrix. A cone calorimeter and a smoke chamber were used to evaluate the performance of the materials against fire and their smokes generation. Global parameters were calculated for comparison purposes. Fires derived from the furan resin combustion grow faster than the phenolic ones, but they are extinguished more rapidly. This effect is enhanced by the incorporation of inorganic nanofillers. The only addition of any clay causes shorter fires but slightly speeds up the degradation process. A homogeneous nanofiller dispersion was found to be crucial to achieve good fire behaviour. Nevertheless, for materials with similar dispersion, the crosslinking degree of the polymer matrix appears as a secondary factor that determines slighter differences in the performance. Nanocomposites with organomodified clays showed a quite similar fire performance, though the composite containing the clay (Southern Clay Products, Inc., Louisville, Ky, USA) Cloisite®30B showed the best performance taking into account both the fire risk and the smoke evolution and obscuration. Copyright © 2013 John Wiley & Sons, Ltd.
The quest for odorants having salicylate notes
Authors: Gaudin Jean‐Marc
Published: October 2013

We describe the synthesis and sensory characterization of a series of compounds which we anticipated would possess the olfactory notes of salicylates. We explored carba‐analogues, cyclic β‐keto esters and cyclic β‐diketones as salicylate analogues. Applying the simple concept of three‐dimensional structure similarity was very fruitful. Salicylate carba‐analogues and β‐keto esters, especially compounds 5, 7 and 10 for the first series and 27 and 28 for the second series, proved to be the most interesting type of compounds. For example, 1‐(2‐hydroxyphenyl)‐3‐phenyl‐1‐propanone (10), which can be found in nature, is nicely diffusive and has an excellent olfactory profile with an interesting dual floral–animal note. In general, these compounds may offer a first credible alternative to the popular salicylates. Copyright © 2013 John Wiley & Sons, Ltd.
A simple sliding‐mesh interface procedure and its application to the CFD simulation of a tidal‐stream turbine
Authors: McNaughton J. , Afgan I. , Apsley D. D. , Rolfo S. , Stallard T. , Stansby P. K.
Published: October 2013

An effective way of using computational fluid dynamics (CFD) to simulate flow about a rotating device—for example, a wind or marine turbine—is to embed a rotating region of cells inside a larger, stationary domain, with a sliding interface between. This paper describes a simple but effective method for implementing this as an internal Dirichlet boundary condition, with interfacial values obtained by interpolation from halo nodes. The method is tested in two finite‐volume codes: one using block‐structured meshes and the other unstructured meshes. Validation is performed for flow around simple, isolated, rotating shapes (cylinder, sphere and cube), comparing, where possible, with experiment and the alternative CFD approach of fixed grid with moving walls. Flow variables are shown to vary smoothly across the sliding interface. Simulations of a tidal‐stream turbine, including both rotor and support, are then performed and compared with towing‐tank experiments. Comparison between CFD and experiment is made for thrust and power coefficients as a function of tip‐speed ratio (TSR) using Reynolds‐averaged Navier–Stokes turbulence models and large‐eddy simulation (LES). Performance of most models is good near the optimal TSR, but simulations underestimate mean thrust and power coefficients in off‐design conditions, with the standard k– ϵ turbulence model performing noticeably worse than shear stress transport k– ω and Reynolds‐stress‐transport closures. LES gave good predictions of mean load coefficients and vital information about wake structures but at substantial computational cost. Grid‐sensitivity studies suggest that Reynolds‐averaged Navier–Stokes models give acceptable predictions of mean power and thrust coefficients on a single device using a mesh of about 4 million cells. Copyright © 2013 John Wiley & Sons, Ltd.
Searching the best equilibrium moisture equation for lettuce seeds using measures of curvature and bias
Authors: Bortolotti Carolina T. , Barrozo Marcos A. S.
Published: October 2013

In the present work, we performed a discrimination analysis of the nonlinear equations used to describe sorption isotherms of the lettuce seeds. The equilibrium data were obtained by the static method using saturated salt solutions. The best model to describe the equilibrium moisture of lettuce seeds was selected using measures of curvature and bias. The obtained results showed that the Copace equation was the best model in terms of nonsignificance for bias and nonlinearity measures.
Hysteresis conditions the vertical position of deep chlorophyll maximum in the temperate ocean
Authors: Navarro Gabriel , Ruiz Javier
Published: October 2013

Deep chlorophyll maxima (DCMs) are widespread features of oceans. In temperate regions, DCMs are commonly associated with isopycnal surfaces that frequently move over a wide vertical range. This general association between DCMs and isopycnals remains unexplained by present theories, and we show here that it emerges from the seasonal history of the water column. Analysis of the formation of more than 9000 seasonal DCMs throughout the world's oceans consistently locates the vertical position of spring/summer DCMs in temperate seas at the density of the previous winter mixed layer, independently of this density value and future depth. These results indicate that DCM formation cannot be understood without hysteresis by solely considering the instantaneous response of phytoplankton to vertical gradients in physical and chemical fields. Present theories for DCM formation cannot explain why spring and summer DCMs are systematically found at a density equal to that of the previous mixed layer where a bloom has occurred. Rather than reacting to instantaneous physical forcing, the results indicate that DCMs operate as self‐preserving biological structures that are associated with particular isopycnals because of their capacity to modify the physicochemical environment. Combined with remote sensors to measure salinity and temperature in the surface ocean, this new understanding of DCM dynamics has the potential to improve the quantification of three‐dimensional primary production via satellites. This significant enhancement of the representation of oceanic biological processes can also allow increasingly realistic predictions of future biogeochemical scenarios in a warming ocean.
Identification of a novel fusion gene involving RUNX1 and the antisense strand of SV2B in a BCR‐ABL1‐positive acute leukemia
Authors: Giguère Amélie , Hébert Josée
Published: October 2013

RUNX1, a key regulator of hematopoiesis, is frequently mutated or implicated in chromosomal translocations in acute leukemia. About half of RUNX1 translocations remain uncharacterized at the molecular level. We describe here one such event, a t(15;21)(q26.1;q22) translocation identified in an adult patient diagnosed with a t(9;22)(q34;q11.2)‐positive acute leukemia. This previously unreported rearrangement yields a fusion of RUNX1 with the antisense strand of the SV2B gene, a new translocation partner of RUNX1, resulting in the expression of out‐of‐frame mRNA chimeric transcripts and the production of putative truncated RUNX1 isoforms. The t(15;21) translocation also dissociates the P1 promoter of RUNX1 from its open reading frame, reducing RUNX1 expression levels in the patient's leukemic cells. Our data suggest that RUNX1 haploinsufficiency collaborates with the BCR‐ABL1 oncogene in this leukemia. The description of this atypical gene fusion is an important addition to the characterization of the pathogenomic mechanisms leading to RUNX1 structural and functional alterations. Furthermore, our data strongly suggests that inadequate dosage of this gene plays an essential role in leukemogenesis. © 2013 Wiley Periodicals, Inc.
The relationship between and clinical significance of MicroRNA‐32 and phosphatase and tensin homologue expression in colorectal cancer
Authors: Wu Weiyun , Yang Pengchun , Feng Xiao , Wang Hao , Qiu Yumei , Tian Ting , He Yanting , Yu Caiyuan , Yang Jingfang , Ye Shicai , Zhou Yu
Published: October 2013

MicroRNAs (miRNAs, miRs) are suspected to play important roles in carcinogenesis. MiR‐32 has altered expression in colorectal cancer (CRC); however, the clinical significance of miR‐32 expression in the process of carcinogenesis is poorly understood. In this study, we determined the levels of, the correlation between, and the clinical significance of the expression of miR‐32 and phosphatase and tensin homologue (PTEN), a tumor suppressor targeted by miR‐32, in CRC. The levels of miR‐32 and PTEN gene expression in 35 colorectal carcinoma samples, 35 corresponding cancer‐adjacent tissue samples, 27 colorectal adenoma samples, and 16 normal tissue samples were quantified using real‐time quantitative reverse transcriptase‐polymerase chain reaction. PTEN protein expression was determined using western blot and immunohistochemistry (IHC). The relationship between the miR‐32 and PTEN protein expression and clinicopathological factors was analyzed. Significant upregulation of miR‐32 expression and reduction of PTEN were identified in CRC tissues. High miR‐32 levels were significantly associated with lymph node and distant metastasis, and Kaplan–Meier analysis indicated that patients with high miR‐32 expression had a poor overall survival. Low PTEN protein expression was also significantly correlated with distant metastasis. An inverse relationship between miR‐32 and PTEN protein expression was identified. In addition, IHC analysis revealed weak or indiscernible PTEN staining in tumor tissue. MiR‐32 overexpression was correlated with specific CRC clinicopathological features and may be a marker of poor prognosis in CRC patients. MiR‐32 and PTEN expression were inversely correlated, and miR‐32 may be associated with the development of CRC. © 2013 Wiley Periodicals, Inc.
Mutated Ephrin Receptor Genes in Non‐Small Cell Lung Carcinoma and Their Occurrence with Driver Mutations—Targeted Resequencing Study on Formalin‐Fixed, Paraffin‐Embedded Tumor Material of 81 Patients
Authors: Mäki‐Nevala Satu , Kaur Sarhadi Virinder , Tuononen Katja , Lagström Sonja , Ellonen Pekka , Rönty Mikko , Wirtanen Aino , Knuuttila Aija , Knuutila Sakari
Published: October 2013

Non‐small cell lung carcinoma (NSCLC) is the most common subtype of lung cancer. The oncogenic potential of receptor tyrosine kinases (RTKs) is widely known and they are potential targets for tailored therapy. Ephrin receptors (Ephs) form the largest group of RTKs. Nevertheless, Ephs are not widely studied in NSCLC so far. The aim of our study was to investigate novel mutations of Eph genes (EPHA1–8, EPHB1–4, EPHB6) and their association with clinically relevant mutations in BRAF, EML4‐ALK, EGFR, INSR, KDR, KRAS, MET, PDGFRA, PDGFRB, PIK3, PTEN, RET, and TP53 in NSCLC patients. Targeted resequencing was conducted on 81 formalin‐fixed, paraffin‐embedded NSCLC tumor specimens. We analyzed missense and nonsense mutations harbored in the coding regions of the selected genes. We found 18 novel mutations of Ephs in 20% (16 of 81) of the patients. Nearly half of these mutations occurred in the protein kinase domain. The mutations were not mutually exclusive with other clinically relevant mutations. Our study shows that Ephs are frequently mutated in NSCLC patients, and occur together with other known mutations relevant to the pathogenicity of NSCLC. © 2013 Wiley Periodicals, Inc.
Marked heterogeneity of HER2/NEU gene amplification in endometrial serous carcinoma
Authors: Buza Natalia , Hui Pei
Published: October 2013

Significant heterogeneity of HER2 protein expression has been recently observed in HER2 positive endometrial serous carcinomas. Tumor cells with HER2 overexpression and/or gene amplification in a heterogeneous tumor may represent a biologically more aggressive subclone that is clinically relevant to prognosis and potential targeted therapy. To correlate with HER2 protein heterogeneity, we investigated the heterogeneity of HER2/NEU gene amplification in endometrial serous carcinoma. A total of 17 endometrial serous carcinomas with heterogeneous HER2 protein expression were selected for the study, including nine cases with a 3+ and eight cases with a 2+ immunohistochemical score. Initial reflex HER2 FISH was available for seven of the eight 2+ cases, five of which showed HER2/NEU gene amplification. All 17 cases underwent repeat FISH targeting larger tumor tissue areas. Ten cases (72%) displayed striking heterogeneity of HER2/NEU gene copy number in the form of cluster amplification. Diffuse HER2 amplification was observed in four cases, no amplification was seen in three tumors. In cases with cluster amplification, HER2 protein overexpression by immunohistochemistry closely correlated at the cellular level with HER2/NEU gene amplification. In conclusion, the significant percentage of cases with heterogeneous HER2/NEU gene amplification indicates that the existing HER2 testing guidelines designed for breast cancer may not be applicable to endometrial serous carcinoma. Clinical testing on multiple different tumor samples or large tumor tissue sections is recommended for both immunohistochemistry and FISH assessment of HER2 status. Direct comparison with the HER2 immunostaining pattern may be helpful in detecting HER2 amplified areas in a heterogeneous tumor. © 2013 Wiley Periodicals, Inc.
Gene‐Environment Interactions in Cancer Epidemiology: A National Cancer Institute Think Tank Report
Authors: Hutter Carolyn M. , Mechanic Leah E. , Chatterjee Nilanjan , Kraft Peter , Gillanders Elizabeth M.
Published: October 2013

Cancer risk is determined by a complex interplay of genetic and environmental factors. Genome‐wide association studies (GWAS) have identified hundreds of common (minor allele frequency [MAF] > 0.05) and less common (0.01 < MAF < 0.05) genetic variants associated with cancer. The marginal effects of most of these variants have been small (odds ratios: 1.1–1.4). There remain unanswered questions on how best to incorporate the joint effects of genes and environment, including gene‐environment (G × E) interactions, into epidemiologic studies of cancer. To help address these questions, and to better inform research priorities and allocation of resources, the National Cancer Institute sponsored a “Gene‐Environment Think Tank” on January 10–11, 2012. The objective of the Think Tank was to facilitate discussions on (1) the state of the science, (2) the goals of G × E interaction studies in cancer epidemiology, and (3) opportunities for developing novel study designs and analysis tools. This report summarizes the Think Tank discussion, with a focus on contemporary approaches to the analysis of G × E interactions. Selecting the appropriate methods requires first identifying the relevant scientific question and rationale, with an important distinction made between analyses aiming to characterize the joint effects of putative or established genetic and environmental factors and analyses aiming to discover novel risk factors or novel interaction effects. Other discussion items include measurement error, statistical power, significance, and replication. Additional designs, exposure assessments, and analytical approaches need to be considered as we move from the current small number of success stories to a fuller understanding of the interplay of genetic and environmental factors.
A Whole‐Genome Simulator Capable of Modeling High‐Order Epistasis for Complex Disease
Authors: Yang Wei , Gu C. Charles
Published: October 2013

Genome‐wide association studies (GWAS) have been successful in finding numerous new risk variants for complex diseases, but the results almost exclusively rely on single‐marker scans. Methods that can analyze joint effects of many variants in GWAS data are still being developed and trialed. To evaluate the performance of such methods it is essential to have a GWAS data simulator that can rapidly simulate a large number of samples, and capture key features of real GWAS data such as linkage disequilibrium (LD) among single‐nucleotide polymorphisms (SNPs) and joint effects of multiple loci (multilocus epistasis). In the current study, we combine techniques for specifying high‐order epistasis among risk SNPs with an existing program GWAsimulator [Li and Li, 2008] to achieve rapid whole‐genome simulation with accurate modeling of complex interactions. We considered various approaches to specifying interaction models including the following: departure from product of marginal effects for pairwise interactions, product terms in logistic regression models for low‐order interactions, and penetrance tables conforming to marginal effect constraints for high‐order interactions or prescribing known biological interactions. Methods for conversion among different model specifications are developed using penetrance table as the fundamental characterization of disease models. The new program, called simGWA, is capable of efficiently generating large samples of GWAS data with high precision. We show that data simulated by simGWA are faithful to template LD structures, and conform to prespecified diseases models with (or without) interactions.
Adjusting for Population Stratification in a Fine Scale With Principal Components and Sequencing Data
Authors: Zhang Yiwei , Shen Xiaotong , Pan Wei
Published: October 2013

Population stratification is of primary interest in genetic studies to infer human evolution history and to avoid spurious findings in association testing. Although it is well studied with high‐density single nucleotide polymorphisms (SNPs) in genome‐wide association studies (GWASs), next‐generation sequencing brings both new opportunities and challenges to uncovering population structures in finer scales. Several recent studies have noticed different confounding effects from variants of different minor allele frequencies (MAFs). In this paper, using a low‐coverage sequencing dataset from the 1000 Genomes Project, we compared a popular method, principal component analysis (PCA), with a recently proposed spectral clustering technique, called spectral dimensional reduction (SDR), in detecting and adjusting for population stratification at the level of ethnic subgroups. We investigated the varying performance of adjusting for population stratification with different types and sets of variants when testing on different types of variants. One main conclusion is that principal components based on all variants or common variants were generally most effective in controlling inflations caused by population stratification; in particular, contrary to many speculations on the effectiveness of rare variants, we did not find much added value with the use of only rare variants. In addition, SDR was confirmed to be more robust than PCA, especially when applied to rare variants.
Global map of solid Earth surface heat flow
Authors: Davies J. Huw
Published: October 2013

A global map of surface heat flow is presented on a 2° × 2° equal area grid. It is based on a global heat flow data set of over 38,000 measurements. The map consists of three components. First, in regions of young ocean crust (<67.7 Ma) the model estimate uses a half‐space conduction model based on the age of the oceanic crust, since it is well known that raw data measurements are frequently influenced by significant hydrothermal circulation. Second, in other regions of data coverage the estimate is based on data measurements. At the map resolution, these two categories (young ocean, data covered) cover 65% of Earth's surface. Third, for all other regions the estimate is based on the assumption that there is a correlation between heat flow and geology. This assumption is assessed and the correlation is found to provide a minor improvement over assuming that heat flow would be represented by the global average. The map is made available digitally.
Prolonged plume volcanism in the Caribbean Large Igneous Province: New insights from Curaçao and Haiti
Authors: Loewen Matthew W. , Duncan Robert A. , Kent Adam J. R. , Krawl Kyle
Published: October 2013

We present 36 new 40Ar‐39Ar incremental heating age determinations from the Caribbean Large Igneous Province (CLIP) providing evidence for extended periods of volcanic activity and suggest a new tectonomagmatic model for the province's timing and construction. These new 40Ar‐39Ar ages for the Curaçao Lava Formation (CLF) and Haiti's Dumisseau Formation show evidence for active CLIP volcanism from 94 to 63 Ma. No clear changes in geochemical character are evident over this period. The CLF has trace element signatures (e.g., Zr/Nb = 10–20) and flat rare earth element (REE) trends consistent with plume volcanism. The Dumisseau Formation also has plume‐like geochemistry and steeper REE trends similar to ocean island basalts. Volcanism in the Dumisseau Formation appears to have largely ceased by 83 Ma while at Curaçao it continued until 63 Ma. A rapidly surfacing and melting plume head alone does not fit this age distribution. Instead, we propose that the residual Galapagos plume head, following initial ocean plateau construction, was advected eastward by asthenospheric flow induced by subducting oceanic lithosphere. Slab rollback at the Lesser Antilles and Central America subduction zones created an extensional regime within the Caribbean plate. Mixing of plume with upwelling asthenospheric mantle provided a source for intermittent melting and eruption through the original plateau over a ∼30 Ma period.
Anomalously thin transition zone and apparently isotropic upper mantle beneath Bermuda: Evidence for upwelling
Authors: Benoit Margaret H. , Long Maureen D. , King Scott D.
Published: October 2013

The origin of the Bermuda swell and volcanism remains enigmatic. The lack of an associated time‐progressive hotspot track and absence of present‐day volcanic activity make it difficult to reconcile with a deep mantle plume model. We analyze shear wave splitting measurements to estimate mantle flow direction and receiver function stacks to place constraints on the mantle transition zone thermal structure. *KS phases exhibit well‐resolved null arrivals (no splitting) beneath the swell over a range of back azimuths. We find that the 410 and 660 km discontinuities are 49 ± 5 km and 19 ± 5 km deeper than the global average, respectively, leading to a transition zone thickness that is 27 ± 4 km thinner than the average. Together, an apparently isotropic upper mantle and a thinned mantle transition zone suggest that mantle flow is primarily vertical beneath the swell, consistent with the presence of hot, buoyant mantle at depth.
Geophysical modeling of collapse‐prone zones at Rumble III seamount, southern Pacific Ocean, New Zealand
Authors: Tontini F. Caratori , de Ronde C. E. J. , Kinsey J. C. , Soule A. , Yoerger D. , Cocchi L.
Published: October 2013

Catastrophic collapses of submarine volcanoes have the potential to generate major tsunami, threatening many coastal populations. Recognizing the difficulties surrounding anticipations of these events, quantitative assessment of collapse‐prone regions based on detailed morphological, geological, and geophysical mapping can still provide important information about the hazards associated with these collapses. Rumble III is one of the shallowest, and largest, submarine volcanoes found along the Kermadec arc, and is both volcanically and hydrothermally active. Previous surveys have delineated major collapse features at Rumble III; based on time‐lapse bathymetry, dramatic changes in the volcano morphology have been shown to have occurred over the interval 2007–2009. Furthermore, this volcano is located just ∼300 km from the east coast of the North Island of New Zealand. Here, we present a geophysical model for Rumble III that provides the locations and sizes of potential weak regions of this volcano. Shipborne and near‐seafloor geological and geophysical data collected by the AUV Sentry are used to determine the subsurface distribution of weak and unstable volcanic rocks. The resulting model provides evidence for potentially unstable areas located in the Southeastern flank of this volcano which should be included in future hazard predictions.
Detection of diffuse seafloor venting using structured light imaging
Authors: Smart Clara J. , Roman Chris , Carey Steven N.
Published: October 2013

Currently, we lack a systematic and remote method for locating and quantifying diffuse seafloor venting using underwater robotic vehicles. Diffuse flow is characterized by both low temperature and low flux rates, which cannot readily be distinguished using current remote visual, acoustic, or vehicle‐mounted environmental sensors. The result is a poor understanding of the distribution, contribution, and context of diffuse flow sources. An underwater structured light imaging system, also used for high‐resolution seafloor bathymetric mapping, has however shown promise in detecting diffuse flows while completing seafloor imaging surveys at a typical altitude of 3 m. The system creates sequential bathymetric profiles by imaging a laser line projected on the seafloor. In the presence of venting fluids, the laser line exhibits a detectable level of distortion due to variations in the refractive index along the optical path. By characterizing the degree of distortion, it is possible to create maps indicating areas of potential venting with sub‐meter spatial resolution. Results from three distinct vent fields are presented and discussed. Analysis of these data sets indicates this system is capable of detecting both small point source vents and near bottom diffuse flow.
Attribution of mild cognitive impairment etiology in patients and their care partners
Authors: Rodakowski Juleen , Schulz Richard , Gentry Amanda , Garand Linda , Lingler Jennifer Hagerty
Published: October 2013

Objective

This study examined the attribution of mild cognitive impairment (MCI) etiology assigned by individuals with MCI and their care partners, and the extent to which the dyads agreed on the attribution of MCI etiology.

Methods

We conducted secondary analyses of cross‐sectional data from a cohort of individuals with MCI (n = 60) and their care partners (n = 60). The mean age of the individuals with MCI was 71.0 ± 9.4 years and of care partners 64.2 ± 11.0 years. The primary outcome was attribution assigned to memory deficits on the Illness Perception Questionnaire. We categorized the attribution of MCI etiology as either potentially controllable or uncontrollable factors. We described the distribution of MCI etiology with descriptive and contingency tables. We determined the odds of a patient or care partner choosing one type of MCI etiology over another.

Results

Although individuals with MCI and their care partners most frequently attributed MCI to uncontrollable factors (81.7% and 61.0%, respectively), care partners were 28.41 (95% CI, 1.26 to 645.48) times more likely to attribute MCI etiology to potentially controllable factors than individuals with MCI. No significant associations between demographic factors and attribution of MCI etiology were found for the individuals with MCI or the care partners.

Conclusion

Findings demonstrated that members of the dyad attributed MCI etiology to different causes. Attributions of MCI etiology should be explored by professionals to clarify misconceptions and potentially improve subsequent voluntary actions intended to assist oneself or others. Copyright © 2013 John Wiley & Sons, Ltd.
Prognosis of delirium in hospitalized elderly: worse than we thought
Authors: Dasgupta Monidipa , Brymer Chris
Published: October 2013

Background

Despite treatment of the associated condition, delirious persons do not always recover for unknown reasons. We sought to determine early prognostic indicators of poor recovery following an episode of delirium in older medical in‐patients.

Methods

Between October 2009 and July 2011, consecutively admitted older (≥70 years old) medical in‐patients at the London Health Sciences Centre (Ontario) were screened for delirium. Delirious patients were followed. The primary outcome was poor recovery, in delirious patients, defined by death, long‐term institutionalization, or functional decline (decreased activities of daily living), at discharge or 3 months after discharge, elicited from the medical chart or post‐discharge caregiver telephone interviews.

Results

One thousand two hundred thirty‐five in‐patients (mean age 82.6 years, 42% men) were screened, delirium occurred in 355 (29%). Follow‐up data was known on 342 (96%), and 237 (69%) had poor recovery: 55 died (54 in hospital and one after discharge), 136 were permanently institutionalized (86 directly from hospital and 50 after discharge), and 46 had functional decline (at a median of 103 days after discharge). Poor recovery was associated in the derivation sample with advanced age, lower baseline function, hypoxia, higher delirium severity scores, and acute renal failure; this was predictive of poor recovery in the validation sample (receiver operating characteristic area 0.68, 95% confidence interval: 0.57–0.79); however, even individuals with “low” risk had high (50%) poor recovery rates.

Interpretation

Poor recovery after delirium is common and associated with certain characteristics. However, even “lower risk” delirious individuals do poorly. More research is needed to understand prognostic factors in delirium. Copyright © 2013 John Wiley & Sons, Ltd.
Amnestic multiple cognitive domains impairment and periventricular white matter hyperintensities are independently predictive factors progression to dementia in mild cognitive impairment
Authors: Lee Hyun Kyung , Lee Young Min , Park Je Min , Lee Byung Dae , Moon Eun Soo , Chung Young In
Published: October 2013

Objective

Mild cognitive impairment (MCI) usually represents a transitional phase between normal cognitive function and dementia, but not all people with MCI develop dementia because MCI is a clinically and etiologically heterogeneous grouping. The aim of this study was to determine whether clinical subtypes of MCI and severity of white matter hyperintensities (WMH) were associated with progression of MCI to dementia.

Method

Our study cohort consisted of 840 patients aged 55 years or older who had a diagnosis of MCI at their baseline visit and had at least one follow‐up contact after baseline.

Results

The results of the multivariable Cox proportional hazards model analysis revealed that both multiple domain amnestic MCI with WMH and multiple domain amnestic MCI without WMH were a significantly more likely to progress to dementia in comparison with patients with non‐amnestic MCI. Logistic regression analyses showed that PWMH (periventricular white matter hyperintensities), not the deep white matter hyperintensities, was significantly associated with incident dementia.

Conclusions

This study showed that mdMCI + a (−NL or ‐WMH) are more associated with progression to dementia. We also found that increasing severity of PWMH, not deep white matter hyperintensities, was significantly associated with incident dementia, independently of subtype of MCI. It suggests that both mdMCI + a and PWMH are good prognostic factors of progression to dementia in MCI. Copyright © 2013 John Wiley & Sons, Ltd.
A comparison of FDG‐PET and blood flow SPECT in the diagnosis of neurodegenerative dementias: a systematic review
Authors: Davison Christopher M. , O'Brien John T.
Published: October 2013

Objective

Perfusion single photon emission computed tomography (SPECT) and 18F fluorodeoxyglucose positron emission tomography (FDG‐PET) both have clinical utility for the differential diagnosis of dementia. Although PET is often viewed by some as more accurate and therefore preferential, the extent to which published evidence supports this is not clear.

The aim of this review was to address the question by reviewing studies of SPECT and PET imaging in dementia diagnosis, with a particular focus on all published head‐to‐head studies.

Design

A MEDLINE search was carried out using the following keywords: “PET” and “SPECT” and “dementia” or “Mild Cognitive Impairment,” together with “alzheimers” or “DLB” or “lewy body” or “frontotemporal” or “FTD” or “Picks.” Articles were included up to February 2013, limited to human studies and in English language.

Results

Published studies of SPECT accuracy show that it is a useful tool for differential diagnosis, with sensitivities of 65–85% for diagnosing Alzheimer's disease (AD) and specificities (for other neurodegenerative dementias) of 72–87%. PET studies generally report higher accuracy, with sensitivities of 75–99% for AD and specificities of 71–93%. However, there have been few direct head‐to‐head comparisons, with some indicating SPECT and PET to be equally useful in dementia diagnosis and others favouring PET. Many of these studies are limited with respect to numbers and methodically with poorly matched control groups.

Conclusions

Overall, although studies suggest superiority of PET over SPECT, the evidence base for this is actually quite limited. We suggest that further direct comparative studies, including health economic and patient preference evaluations, are needed to help direct future service provision. Copyright © 2013 John Wiley & Sons, Ltd.
Low‐order stochastic model and “past‐noise forecasting” of the Madden‐Julian Oscillation
Authors: Kondrashov D. , Chekroun M. D. , Robertson A. W. , Ghil M.
Published: October 2013

This paper presents a predictability study of the Madden‐Julian Oscillation (MJO) that relies on combining empirical model reduction (EMR) with the “past‐noise forecasting” (PNF) method. EMR is a data‐driven methodology for constructing stochastic low‐dimensional models that account for nonlinearity, seasonality and serial correlation in the estimated noise, while PNF constructs an ensemble of forecasts that accounts for interactions between (i) high‐frequency variability (noise), estimated here by EMR, and (ii) the low‐frequency mode of MJO, as captured by singular spectrum analysis (SSA). A key result is that—compared to an EMR ensemble driven by generic white noise—PNF is able to considerably improve prediction of MJO phase. When forecasts are initiated from weak MJO conditions, the useful skill is of up to 30 days. PNF also significantly improves MJO prediction skill for forecasts that start over the Indian Ocean.
Investigation of cosmic ray–cloud connections using MISR
Authors: Krissansen‐Totton Joshua , Davies Roger
Published: October 2013

Numerous empirical studies have analyzed International Satellite Cloud Climatology Project data and reached contradictory conclusions regarding the influence of solar‐modulated galactic cosmic rays on cloud fraction and cloud properties. The Multiangle Imaging Spectroradiometer (MISR) instrument on the Terra satellite has been in continuous operation for 13 years and thus provides an independent (and previously unutilized) cloud data set to investigate purported solar‐cloud links. Furthermore, unlike many previous solar‐climate studies that report cloud fraction MISR measures albedo, which has clearer climatological relevance. Our long‐term analysis of MISR data finds no statistically significant correlations between cosmic rays and global albedo or globally averaged cloud height, and no evidence for any regional or lagged correlations. Moreover, epoch superposition analysis of Forbush decreases reveals no detectable albedo response to cosmic ray decreases, thereby placing an upper limit on the possible influence of cosmic ray variations on global albedo of 0.0029 per 5% decrease. The implications for recent global warming are discussed.
Bidirectional exchange of methyl halides between tropical plants and the atmosphere
Authors: Saito Takuya , Yokouchi Yoko , Phillip Elizabeth , Okuda Toshinori
Published: October 2013

Using a stable isotope tracer technique, we studied the exchange of methyl chloride (CH3Cl) and methyl bromide (CH3Br) between plants and the atmosphere in a tropical rain forest in Malaysia. Most plant species examined showed not only production but also consumption of CH3Cl with a large net emission overall. In contrast, CH3Br consumption was comparable to its production, so the net emission was small. The rates of CH3Cl and CH3Br consumption were highly correlated with each other, and their ratio was consistent with reported values in terrestrial ecosystems, where microorganisms are responsible for the consumption. Such microorganisms might participate in the consumption we observed, as the consumption rates were faster in saplings, whose leaves were generally covered by epiphytic microorganisms, than in healthy looking leaves of mature trees.
Large‐scale climate control of zooplankton transport and biogeography in the Kuroshio‐Oyashio Extension region
Authors: Chiba Sanae , Di Lorenzo Emanuele , Davis Andrew , Keister Julie E. , Taguchi Bunmei , Sasai Yoshikazu , Sugisaki Hiroya
Published: October 2013

We studied decadal‐scale climate control of zooplankton biogeography driven by Kuroshio Extension (KE) dynamics using long‐term zooplankton data and an advection model driven with currents from the Earth Simulator eddy‐resolving ocean model. Passive tracer model experiments indicated that warm‐water species transported from the south were retained in the Kuroshio‐Oyashio Extension (KOE) region during years with a weak KE. A 2.5 year lag in the North Pacific Gyre Oscillation (NPGO) index was significantly correlated with the KE strength and with warm‐water species abundance. These findings indicate that climate signals from the central and eastern North Pacific propagated westward, influencing not only transport in the KOE region but also regional ecosystem variability. Because the NPGO controls important aspects of the transport dynamics and ecosystem variability in the eastern North Pacific, this study provides additional evidence that large‐scale climate patterns drive coherent changes in ecosystems throughout the North Pacific by impacting regional‐scale transport dynamics.
Estuarine acidification and minimum buffer zone—A conceptual study
Authors: Hu Xinping , Cai Wei‐Jun
Published: October 2013

This study uses a simulation method to explore how estuarine pH is affected by mixing between river water, anthropogenic CO2 enriched seawater, and by respiration. Three rivers with different levels of weathering products (Amazon, Mississippi, and St. Johns) are selected for this simulation. The results indicate that estuaries that receive low to moderate levels of weathering products (Amazon and St. Johns) exhibit a maximum pH decrease in the midsalinity region as a result of anthropogenic CO2 intrusion. This maximum pH decrease coincides with a previously unrecognized mid‐salinity minimum buffer zone (MBZ). In addition, water column oxygen consumption can further depress pH for all simulated estuaries. We suggest that recognition of the estuarine MBZs may be important for studying estuarine calcifying organisms and pH‐sensitive biogeochemical processes.
Recovering coseismic point ground tilts from collocated high‐rate GPS and accelerometers
Authors: Geng Jianghui , Melgar Diego , Bock Yehuda , Pantoli Elide , Restrepo José
Published: October 2013

Rotational along with translational and strain measurements are essential for a complete description of the motion of a deformable body in a seismic event. We propose a new seismogeodetic approach where collocated high‐rate GPS and accelerometer measurements are combined to estimate permanent and dynamic coseismic ground tilts at a point, whereas at present, only dynamic tilts are measured with either a dense seismic array or an expensive ring laser gyroscope. We estimate point tilts for a five‐story structure on a shake table subjected to 13 earthquake strong motion records of increasing intensity. For the most intense record from the 2002 M7.9 Denali earthquake, we observe a peak‐to‐peak dynamic tilt of 0.12° and a permanent tilt of 0.16° for the structure's roof. Point tilts derived from networks of collocated GPS and accelerometers can be used to estimate the rotational component of the seismic wavefield for improved earthquake source characterization.
Ferromagnetism of iron under pressure to 21.5 GPa
Authors: Wei Qingguo , Gilder Stuart A.
Published: October 2013

Computational, Mössbauer, and synchrotron radiation experiments arrive at disparate conclusions regarding the magnetic state of the high‐pressure, hexagonal closed packed, phase of iron, which likely comprises the bulk composition of Earth's inner core. Using a nonmagnetic, moissanite anvil cell together with a superconducting magnetometer, we measured the remanent magnetization of iron in response to applied magnetic fields under pressure up to 21.5 GPa at room temperature. Two independent experiments using different pressure transmission media reveal a higher remanent magnetization at 21.5 GPa than at initial conditions, which could be attributed to a distorted hexagonal closed packed phase grown during the martensitic transition. Upon both compression and decompression, the remanent magnetization of the body centered cubic phase increases several times over initial conditions while the coercivity of remanence remains mostly invariant with pressure.