bluuebunny/crossref_metadata_2025 huggingface dataset:
Real‐time Kalman filtering based on distributed measurements
Authors: Cui Peng , Zhang Huanshui , Lam James , Ma Lifeng
Published: May 2012

A kind of real‐time Kalman filtering problem is discussed for systems with distributed multichannel measurements. Recursive filters are presented for two cases with correlated and uncorrelated measurement noises. An optimal algorithm is constructed using projection theory in Hilbert space according to a first‐come‐first‐served scheme. An update is generated whenever a new measurement arrives at a central unit. Therefore, the algorithm has the practical advantages of flexibility and the easiness for real‐time implementation. Copyright © 2012 John Wiley & Sons, Ltd.
Invertibility of symmetric random matrices
Authors: Vershynin Roman
Published: May 2012

We study symmetric random matrices H, possibly discrete, with iid above‐diagonal entries. We show that H is singular with probability at most , and . Furthermore, the spectrum of H is delocalized on the optimal scale . These results improve upon a polynomial singularity bound due to Costello, Tao and Vu, and they generalize, up to constant factors, results of Tao and Vu, and Erdös, Schlein and Yau.Copyright © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 44, 135‐182, 2014
Directional spread‐spectrum modulation signal for physical layer security communication applications
Authors: Hong Tao , Song Mao‐zhong , Liu Yu
Published: May 2012

In this paper, we propose a directional spread‐spectrum modulation (DSM) signal transmitted by a switched antenna array for physical layer security communication. The main idea is that the antenna hopping scheme is designed according to a spreading sequence. Fundamental frequency component and all harmonic components generated by antenna hopping are used to form the DSM signal with the characteristic of being directional. This signal is associated with the spreading sequence and the direction of the desired receiver because of DSM signal modulated both in the baseband and the antenna level. In this way, the desired receiver with a single antenna demodulates the receive signal as traditional spread‐spectrum signal, whereas eavesdroppers cannot extract any useful information from the receive signal even if eavesdroppers know the spreading sequence of DSM signal. Finally, simulation results show that the proposed signal offers a more secure transmission method for wireless communication compared with the traditional spread‐spectrum signal. Copyright © 2012 John Wiley & Sons, Ltd.
A more secure and scalable routing protocol for mobile ad hoc networks
Authors: Qabajeh Liana Khamis , Kiah Miss Laiha Mat , Qabajeh Mohammad Moustafa
Published: May 2012

An essential problem in mobile ad hoc networks is finding an efficient and secure route from a source to an intended destination. In this paper, we have proposed a new model of routing protocol named ARANz, which is an extension of the original Authenticated Routing for Ad Hoc Networks (ARAN). ARANz adopts the authentication methods used with ARAN and aims to increase security, achieve robustness and solve the single point of failure and attack problems by introducing multiple local certificate authority servers. Additionally, via dealing with the network as zones and using restricted directional flooding, our new model exhibits better scalability and performance. Through simulation, we evaluated ARANz and compared it with the original ARAN as well as Ad Hoc On‐demand Distance Vector. Simulation results show that ARANz is able to effectively discover secure routes within relatively large networks with large number of mobile nodes, while maintaining the minimum packet routing load. Copyright © 2012 John Wiley & Sons, Ltd.
Determination of size and density of embedded Ge nanocrystals in SiO2 by scanning force microscopy using a tomographic approach
Authors: Beyer R. , von Borany J.
Published: May 2012

Germanium nanocrystals in silicon dioxide were studied by atomic force microscopy (AFM) to reveal their size, density and distribution. The generation of the nanocrystals was accomplished by Ge+ ion implantation into a 100‐nm silicon dioxide layer and subsequent annealing at high temperatures in an inert atmosphere. Rutherford backscattering spectroscopy was applied to reveal the Ge distribution after implantation and annealing, and the formation of the nanocrystals was proven by transmission electron microscopy. The oxide layer was gradually etched to uncover the nanocrystals located at different depth positions within the SiO2 layer. Subsequently, the unveiled surfaces were examined by AFM in order to determine the size and density of the exposed nanocrystals. A correlation between the nanocrystal properties and the Ge implantation dose was corroborated. Copyright © 2012 John Wiley & Sons, Ltd.
Nanotribological behavior of thermal treatment of zinc titanate thin films
Authors: Wu Shyh‐Chi , Yau Wei‐Hung , Tsai Chien‐Huang , Chou Chang‐Pin
Published: May 2012

We present a study of the nanotribological behavior of ZnTiO3 films; the surface morphology, stoichiometry, and friction (μ) were analyzed using atomic force microscopy, X‐ray photoelectron spectroscopy, and nanoscratch system. It is confirmed that the measured values of H and μ of the ZnTiO3 films were in the range from 8.5 ± 0.4 to 5.6 ± 0.4 GPa and from 0.164 to 0.226, respectively. It is suggested that the hexagonal ZnTiO3 decomposes into cubic Zn2TiO4 and rutile TiO2 based on the thermal treatment; the H, μ, and RMS were changed owing to the grain growth and recovery that results in a relax crystallinity of ZnTiO3 films. From X‐ray photoelectron spectroscopy measured, core levels of O 1 can attribute the weaker bonds as well as lower resistance after thermal treatment. The XRD patterns showed that as‐deposited films are mainly amorphous; however, the hexagonal ZnTiO3 phase was observed with the ZnTiO3 (104), (110), (116), and (214) peaks from 620 to 820 °C, indicating that there is highly (104)‐oriented ZnTiO3 on the silicon substrate. Copyright © 2012 John Wiley & Sons, Ltd.
An attempt of improving polyester inkjet printing performance by surface modification using β‐cyclodextrin
Authors: Chen Li , Wang Chaoxia , Tian Anli , Wu Min
Published: May 2012

To improve the sharpness and the color yield of polyester fabrics with water‐based pigment inkjet printing, surface modification was proceeded using β‐cyclodextrin and citric acid. Fabrics were modified in the solution of β‐cyclodextrin with the concentration 100g/L and citric acid 100g/L. The line width and image area of printed patterns, which could evaluate the printing performances, on the modified polyester fabric were decreased by 77% and 62% in comparison with that of the control, respectively. The color yield characterized by the K/S value was enhanced by 47%. Scanning electron microscope and atomic force microscope images confirmed that the capillary effect was decreased and the surface roughness was increased after the surface modification. The microscope images of the printed patterns clearly showed that the sharpness and the color yield were improved. Thereby, β‐cyclodextrin modification offered a potential way to polyester pretreatment for pigment inkjet printing. Copyright © 2012 John Wiley & Sons, Ltd.
Substrate temperature influenced physical properties of silicon MOS devices with TiO2 gate dielectric
Authors: Chandra Sekhar M. , Kondaiah P. , Jagadeesh Chandra S. V. , Mohan Rao G. , Uthanna S.
Published: May 2012

DC reactive magnetron sputtering technique was employed for deposition of titanium dioxide (TiO2) films. The films were formed on Corning glass and p‐Si (100) substrates by sputtering of titanium target in an oxygen partial pressure of 6×10−2 Pa and at different substrate temperatures in the range 303 – 673 K. The films formed at 303 K were X‐ray amorphous whereas those deposited at substrate temperatures ≥ 473 K were transformed into polycrystalline nature with anatase phase of TiO2. Fourier transform infrared spectroscopic studies confirmed the presence of characteristic bonding configuration of TiO2. The surface morphology of the films was significantly influenced by the substrate temperature. MOS capacitor with Al/TiO2/p‐Si sandwich structure was fabricated and performed current–voltage and capacitance–voltage characteristics. At an applied gate voltage of 1.5 V, the leakage current density of the device decreased from 1.8 × 10−6 to 5.4 × 10−8 A/cm2 with the increase of substrate temperature from 303 to 673 K. The electrical conduction in the MOS structure was more predominant with Schottky emission and Fowler‐Nordheim conduction. The dielectric constant (at 1 MHz) of the films increased from 6 to 20 with increase of substrate temperature. The optical band gap of the films increased from 3.50 to 3.56 eV and refractive index from 2.20 to 2.37 with the increase of substrate temperature from 303 to 673 K. Copyright © 2012 John Wiley & Sons, Ltd.
Firm heterogeneity in growth option value: The role of managerial incentives
Authors: Alessandri Todd M. , Tong Tony W. , Reuer Jeffrey J.
Published: May 2012

Growth option value varies widely across firms. This research explores managerial incentives as a source of firm heterogeneity in growth option value. We argue that when the payoff structure of managerial incentives corresponds to that of growth options, managers will be motivated to pursue actions that increase firms' growth option value, particularly when greater growth opportunities are available in an industry. Results indicate that stock option holdings and managerial stock ownership have a positive effect on growth option value, while short‐term pay has a negative effect. We also find support for a positive interaction effect between equity‐based managerial incentives and industry growth opportunities on growth option value. These findings highlight the critical role of managerial incentives in affecting firms' realization of growth option value. Copyright © 2012 John Wiley & Sons, Ltd.
Bin smoother
Authors: Klemelä Jussi
Published: May 2012

Bin smoothers, or regressograms, are piecewise constant regression function estimators whose values are averages of the response variable over the sets of a partition of the space of the explanatory variables. First, we review results about bin smoothers whose partition is regular, giving conditions for consistency and for achieving the optimal rate of convergence. Second, we review representative results about bin smoothers whose partition is irregular, again giving conditions for consistency and for achieving the optimal rate of convergence. Third, we give an exposition of recursive partitioning, main examples being greedy partitions and the classification and regression tress (CART) methodology. WIREs Comput Stat 2012 doi: 10.1002/wics.1214

This article is categorized under:

Statistical Learning and Exploratory Methods of the Data Sciences > Classification and Regression Trees (CART)

Statistical and Graphical Methods of Data Analysis > Density Estimation

Statistical and Graphical Methods of Data Analysis > Nonparametric Methods
Evaluating population estimates of mountain goats based on citizen science
Authors: Belt Jami J. , Krausman Paul R.
Published: May 2012

Citizen science programs that use trained volunteers may be a cost‐effective method for monitoring wildlife at large scales. However, few studies have compared data collected by volunteers versus biologists. In Glacier National Park (GNP), Montana, USA, we assessed whether citizen science is a useful method to monitor mountain goat (Oreamnos americanus) populations. We compared estimates of mountain goat abundance by volunteers at 32 sites throughout GNP with estimates by biologists and aerial surveys at a subset of 25 and 11 sites, respectively. We used multiple‐observer surveys to calibrate the indices of abundance at each site for observer variation between volunteers and biologists. We used N‐mixture models to obtain estimates of abundance across all sites. Population estimates by citizen scientists overlapped estimates by biologists. Density estimates from aerial surveys were lower than ground estimates. Mean detection probability from multiple‐observer surveys for biologists was significantly higher and less variable than that of volunteers. More frequent site visits balanced out lower detection probability by volunteers and resulted in abundance estimates that were less variable than those of biologists. When large spatial and temporal coverage can be achieved, citizen science can provide mountain goat population estimates that are statistically similar to those of biologists. © 2012 The Wildlife Society.
Simulating carnivore movements: An occupancy–abundance relationship for surveying wolves
Authors: Webb Nathan F. , Merrill Evelyn H.
Published: May 2012

Where carnivore species exist at low densities, are cryptic, and inhabit forested habitats where detection is low, survey approaches commonly rely on observation of tracks. Recent advances in probability sampling for aerial surveys of track networks in snow show promise for improving density estimates, but they are not applicable when continuously following a track network is not possible. Occupancy–abundance modeling is an alternative survey approach for wide‐ranging carnivores, but past models may not be appropriate when using tracks because tracks of one individual or group of individuals may extend across several survey units. We derived an occupancy–abundance relationship by simulating the intersection of wolf (Canis lupus) travel paths and survey grid cells for a range of wolf‐pack densities. Wolf movement paths were simulated using a habitat‐biased, correlated random walk movement model using step lengths and turning angles of 17 Global Positioning System (GPS)‐collared wolves in west‐central Alberta, Canada. We estimated occupancy levels for a range of pack densities found in North America and found that pack density was linearly related to the proportion of occupied survey units. Concurrent movement paths of 5 GPS‐collared wolf packs were used to evaluate the model predictions. While the model overestimated the number of packs by 33%, the difference translated into only 13 wolves across the study area. We discuss improvements for continued development of occupancy surveys as a potential method to determine carnivore abundance where other approaches are not feasible. © 2012 The Wildlife Society.
Systems pharmacology, pharmacogenetics, and clinical trial design in network medicine
Authors: Antman Elliott , Weiss Scott , Loscalzo Joseph
Published: May 2012

The rapidly growing disciplines of systems biology and network science are now poised to meet the fields of clinical medicine and pharmacology. Principles of systems pharmacology can be applied to drug design and, ultimately, testing in human clinical trials. Rather than focusing exclusively on single drug targets, systems pharmacology examines the holistic response of a phenotype‐dependent pathway or pathways to drug perturbation. Knowledge of individual pharmacogenetic profiles further modulates the responses to these drug perturbations, moving the field toward more individualized (‘personalized’) drug development. The speed with which the information required to assess these system responses and their genomic underpinnings is changing and the importance of identifying the optimal drug or drug combinations for maximal benefit and minimal risk require that clinical trial design strategies be adaptable. In this paper, we review the tenets of adaptive clinical trial design as they may apply to an era of expanding knowledge of systems pharmacology and pharmacogenomics, and clinical trail design in network medicine. WIREs Syst Biol Med 2011 DOI: 10.1002/wsbm.1173

This article is categorized under:

Physiology > Mammalian Physiology in Health and Disease

Translational, Genomic, and Systems Medicine > Translational Medicine
Tumoral epithelial and stromal expression of SMAD proteins in pancreatic ductal adenocarcinomas
Authors: Handra‐Luca Adriana , Hammel Pascal , Sauvanet Alain , Ruszniewski Philippe , Couvelard Anne
Published: May 2012

Background

SMAD proteins, intracellular mediators of the transforming growth factor (TGF)‐beta pathway, function within two axes, the SMAD1/5/8 and SMAD2/3, connected to TGF‐beta and bone morphogenetic protein (BMP) ligands. The SMAD proteins of these two axes dimerize with SMAD4 and translocate to the nucleus. SMAD signaling is characterized by a dichotomic functioning, with tumor‐suppressive functions and with loss of normal growth inhibitory responses, depending on the carcinogenesis stage. SMAD proteins also have pro‐tumor effects including abnormal extracellular matrix production. Among tumors, pancreatic cancers harbor SMAD4 inactivation the most frequently and the SMAD proteins are considered to be key factors in pancreatic carcinogenesis.

Methods

Our aims were to study the expression patterns of the different types of SMAD proteins in pancreatic ductal adenocarcinomas treated by surgical resection (without neoadjuvant treatment) and their correlations with morphological and clinical characteristics. We examined the immunohistochemical expression of SMAD4, SMAD1/5/8, and SMAD2/3 in 99 pancreatic ductal adenocarcinomas. Antibodies directed against the activated, phosphorylated forms of proteins were used when appropriate (SMAD1/5/8, SMAD2/3). Protein expression in the epithelial tumor cells and in stromal fibroblasts was analyzed with regard to morphological and clinical data.

Results

Epithelial tumor cells showed SMAD1/5/8, SMAD2/3, and, SMAD4 expression in 13, 93, and 45 tumors, respectively, and stromal fibroblast expression in 5, 11, and 22 tumors, respectively. Epithelial SMAD4 was associated with a low, T1 or T2, TNM stage, and with the presence of an abundant stroma (p = 0.05 and <0.01, respectively). Activated stromal fibroblast SMAD2/3 expression was correlated with the presence of a fibrotic focus (p = 0.01), whereas fibroblast SMAD4 was related to a tendency for shorter postsurgical overall survival (p = 0.07). The relationship of stromal, fibroblast SMAD4 to a worse outcome attained statistical significance in the group of patients with T1 and with N1 stage tumors (p < 0.01 and p = 0.04, respectively).

Conclusion

In pancreatic ductal adenocarcinomas, SMAD protein expression in epithelial tumor cells or in stromal fibroblasts was related to stromal features and to a shorter postsurgical overall survival. Our results point out that the SMAD proteins play a role in the microenvironment of this highly fibrotic tumor type.
Treatment of Two-Part Proximal Humerus Fractures: Intramedullary Nail Compared to Locked Plating
Authors: Lekic Nikola , Montero Nicole M. , Takemoto Richelle C. , Davidovitch Roy I. , Egol Kenneth A.
Published: May 2012

Background

Two-part proximal humerus fractures are common orthopedic injuries for which surgical intervention is often indicated. Choosing a fixation device remains a topic of debate.

Purpose

The purpose of this study is to compare two methods of fixation for two-part proximal humerus fractures, locking plate (LP) with screws versus intramedullary nailing (IMN), with respect to alignment, healing, patient outcomes, and complications. To our knowledge, a direct comparison of these two devices in treating two-part proximal humerus fractures has never before been studied. We hope that our results will help surgeons assess the utility of LP versus IMN.

Methods

A retrospective chart review was performed on 24 cases of displaced two-part surgical neck fractures of the humerus. Twelve shoulders were treated using IMN fixation and 12 others were fixated with LP. Data collected included sociodemographic, operative details, and postoperative care and function.

Results

Radiographic comparison of fixation demonstrated an average neck-shaft angle of 124° and 120° in the IMN group and LP group, respectively. Adjusted postoperative 6-month follow-up range of motion was 134° of forward elevation in the IMN group and 141 in the LP group. The differences in range of motion and in complication rates were not found to be significant.

Conclusions

Our results suggest that either LP fixation or IMN fixation for a two-part proximal humerus fracture provides acceptable fixation and results in a similar range of shoulder motion. Although complication rates were low and insignificant between the two groups, a trend toward increased complications in the IMN group is noted.
Steel‐Corrosion Inhibitors Derived from Soybean Oil
Authors: Graiver D. , Dacomba R. , Khawaji M. , Jaros A. , Berglund K. , Narayan R.
Published: May 2012

Soybean oil derivatives containing a Schiff‐base (SOS‐B) were prepared and evaluated as microbial corrosion inhibitors against sulfate‐reducing bacteria using the gram‐positive Desulfosporosinus orientis bacteria as a representative bacterium. These SOS‐B compounds were also found to be excellent inhibitors against acidic corrosion of carbon steel. These soybean oil derivatives were prepared by ozonation of soybean oil to yield aldehyde functional intermediates which were then reacted with benzylamine to produce a mixture of imine functional triglycerides and linear compounds. The structure of these soy‐based derivatives was confirmed by FTIR and NMR. It was found that the addition of these SOS‐B compounds to D. orientis culture provided a complete inhibition of this bacterium. Furthermore, almost no corrosion of carbon steel panels was observed when the panels were aged in 2N HCl solution containing 10 ppm of these SOS‐B compounds.
TAL—Template Authoring Language
Authors: Soares Neto Carlos de Salles , Soares Luiz Fernando Gomes , de Souza Clarisse Sieckenius
Published: May 2012

This paper presents TAL (Template Authoring Language), an authoring language for hypermedia document templates. Templates describe document families with structural or semantic similarities among them. TAL supports the description of templates independently of the target hypermedia authoring language. The paper also presents a TAL processor that generates complete hypermedia documents taking as input a template specification in TAL and a data file with the information that makes that document particular in its family.
Drosophila Bicoid is a substrate of sumoylation and its activator function is subject to inhibition by this post‐translational modification
Authors: Liu Junbo , Ma Jun
Published: May 2012

Bicoid (Bcd) is a Drosophila morphogenetic protein and a transcriptional activator. Genetic studies have suggested a role of sumoylation in Bcd function, but it is unknown how Bcd activity is affected specifically by its own sumoylation status. Here we show that Bcd is sumoylated in Drosophila cells. We identify a lysine residue of Bcd as the primary sumoylation site. Using a Bcd mutant defective in being sumoylated, we show that sumoylation of Bcd is inhibitory to its ability to activate transcription. We provide evidence suggesting that the SUMO moiety has an intrinsic inhibitory activity for the activator function of Bcd.
Protein translocation as a tool: The current rapamycin story
Authors: Putyrski Mateusz , Schultz Carsten
Published: May 2012

In cell biology and pharmacology, small chemicals are mostly used as agonists and antagonists against receptors and enzymes. The immunosuppressant rapamycin can serve an entirely different purpose: if employed sensibly, it might function as an inducer of dimerization that is able to rapidly activate enzyme activity inside the intact cell. A number of very recent developments such as photoactivatable derivatives make rapamycin an even more attractive tool for basic science.
A new twist to coiled coil
Authors: Le Rumeur Elisabeth , Hubert Jean-François , Winder Steve J.
Published: May 2012

Spectrin repeats have been largely considered as passive linkers or spacers with little functional role other than to convey flexibility to a protein. Whilst this is undoubtedly part of their function, it is by no means all. Whilst the overt structure of all spectrin repeats is a simple triple‐helical coiled coil, the linkages between repeats and the surface properties of repeats vary widely. Spectrin repeats in different proteins can act as dimerisation interfaces, platforms for the recruitment of signalling molecules, and as a site for the interaction with cytoskeletal elements and even direct association with membrane lipids. In the case of dystrophin several of these functions overlap in the space of a few repeats.
BRCT domains: A little more than kin, and less than kind
Authors: Gerloff Dietlind L. , Woods Nicholas T. , Farago April A. , Monteiro Alvaro N.A.
Published: May 2012

BRCT domains are versatile protein modular domains found as single units or as multiple copies in more than 20 different proteins in the human genome. Interestingly, most BRCT‐containing proteins function in the same biological process, the DNA damage response network, but show specificity in their molecular interactions. BRCT domains have been found to bind a wide array of ligands from proteins, phosphorylated linear motifs, and DNA. Here we discuss the biology of BRCT domains and how a domain‐centric analysis can aid in the understanding of signal transduction events in the DNA damage response network.
Structural and functional consequences of mutating a proteobacteria‐specific surface residue in the catalytic domain of Escherichia coli GluRS
Authors: Dasgupta Saumya , Manna Debasis , Basu Gautam
Published: May 2012

Nucleotides whose mutations seriously affect glutamylation efficiency are experimentally known for Escherichia coli tRNAGlu. However, not much is known about functional hotspots on the complementary enzyme, glutamyl‐tRNA synthetase (GluRS). From structural and functional studies on an Arg266Leu mutant of E. coli GluRS, we demonstrate that Arg266 is essential for efficient glutamylation of tRNAGlu. Consistent with this result, we found that Arg266 is a conserved signature of proteobacterial GluRS. In contrast, most non‐proteobacterial GluRS contain Leu, and never Arg, at this position. Our results imply a unique strategy of glutamylation of tRNAGlu in proteobacteria under phylum‐specific evolutionary compulsions.
Heterogeneity in the Effects of Online Persuasion
Authors: Kaptein Maurits , Eckles Dean
Published: May 2012

Average effects of influence strategies on consumers’ attitudes and behaviors have been studied extensively. Less is known about the relative size of individual differences in these effects, despite recognition of their importance in social psychology. Two experiments use repeated exposures to influence strategies to identify the effects of each social influence strategy for individual participants. Study 1 provides evidence of large variation in the effects of influence strategies, such that for many participants the estimated effect of using an influence strategy is negative, even though the effect of that strategy is significantly positive on average. Study 2 replicates these findings over three sessions, each a week apart. The observed variation in responses to influence strategies cannot be attributed to transient intra-individual variation (e.g., strategy × mood interactions). Meta-judgmental measures of personality constructs (e.g., need for cognition) explain only a small portion of the observed variance, suggesting the importance of directly modeling heterogeneity in responses to influence attempts. These results are important for interactive marketeers since they indicate that different influence strategies substantially differ in their effects on individual consumers and should thus be adapted to individuals.
Carbon Nanotube and Graphene Device Physics
Authors: Wong H.-S. Philip , Akinwande Deji
Published: May 2012

Explaining the properties and performance of practical nanotube devices and related applications, this is the first introductory textbook on the subject. All the fundamental concepts are introduced, so that readers without an advanced scientific background can follow all the major ideas and results. Additional topics covered include nanotube transistors and interconnects, and the basic physics of graphene. Problem sets at the end of every chapter allow readers to test their knowledge of the material covered and gain a greater understanding of the analytical skill sets developed in the text. This is an ideal textbook for senior undergraduate and graduate students taking courses in semiconductor device physics and nanoelectronics. It is also a perfect self-study guide for professional device engineers and researchers.
Orally administered [14C]DPA and [14C]DHA are metabolised differently to [14C]EPA in rats
Authors: Kaur Gunveen , Molero Juan C. , Weisinger Harrison S. , Sinclair Andrew J.
Published: May 2012

Previous studies have revealed that C20 PUFA are significantly less oxidised to CO2in whole-body studies compared with SFA, MUFA and C18 PUFA. The present study determined the extent to which three long-chain PUFA, namely 20 : 5n-3 EPA, 22 : 5n-3 docosapentaenoic acid (DPA) and 22 : 6n-3 DHA, were catabolised to CO2or, conversely, incorporated into tissue lipids. Rats were administered a single oral dose of 2·5 μCi [1-14C]DPA, [1-14C]EPA, [1-14C]DHA or [1-14C]oleic acid (18 : 1n-9; OA), and were placed in a metabolism chamber for 6 h where exhaled14CO2was trapped and counted for radioactivity. Rats were euthanised after 24 h and tissues were removed for analysis of radioactivity in tissue lipids. The results showed that DPA and DHA were catabolised to CO2significantly less compared with EPA and OA (P< 0·05). The phospholipid (PL) fraction was the most labelled for all threen-3 PUFA compared with OA in all tissues, and there was no difference between C20 and C22n-3 PUFA in the proportion of label in the PL fraction. The DHA and DPA groups showed significantly more label than the EPA group in both skeletal muscle and heart. In the brain and heart tissue, there was significantly less label in the cholesterol fraction from the C22n-3 PUFA group compared with the C20n-3 PUFA group. The higher incorporation of DHA and DPA into the heart and skeletal muscle, compared with EPA, suggests that these C22n-3 PUFA might play an important role in these tissues.
Age, growth and population structure of jumbo flying squid, Dosidicus gigas, off the Costa Rica Dome
Authors: Chen Xinjun , Li Jianhua , Liu Bilin , Chen Yong , Li Gang , Fang Zhou , Tian Siquan
Published: May 2012

Based on the samples collected in Chinese scientific surveys off the Costa Rica Dome from July to August in 2009, statolith microstructure of the jumbo flying squid, Dosidicus gigas, was analysed for studying their age, growth and population structure. Three typical growth zones (postnuclear, dark and peripheral zones), abnormal increments (checks) and aberrant microstructure (additional centre and additional rings) were found in the statoliths examined. Squid sizes ranged from 205 to 429 mm dorsal mantle length (ML) with ages no more than 10 months for females and 8 months for males. Back-calculated hatching dates were from November 2008 to April 2009. Growth in ML was best described by a linear function for both the sexes, while growth in body weight was best quantified by an exponential function for females and a power curve for males. The maximum absolute daily growth rates and instantaneous growth rate in ML were reached during 181–210 and 151–180 days for females and males, respectively. The Costa Rica Dome and its adjacent waters were considered as a potential spawning ground because of presence of not only high proportion of mature squid but also rhynchoteuthion paralarvae, and high primary productivity from the strong upwelling. This study suggests that D. gigas have complicated intra-specific population structure and large spatial variability in the key life history parameters.
Attitudes to food differ between adolescent dieters and non-dieters from Otago, New Zealand, but overall food intake does not
Authors: Howe Anna S , Mandic Sandra , Parnell Winsome R , Skidmore Paula ML
Published: May 2012

Objective

There is increasing pressure for adolescents to be thin and this may not always be acted upon in healthy ways; for example, certain foods or food groups may be restricted or meals skipped. As foods are not eaten in isolation it is useful to examine dietary patterns and associated psychosocial factors to better understand eating behaviour. The aim of the present study was to identify correlates of ‘dieting’ in adolescents from Otago, New Zealand.

Design

A web-based survey was conducted in 2009, collecting information on food consumption and factors potentially associated with food consumption. Principal components analysis was used to investigate dietary patterns. Correlates were examined in 1329 students using multiple logistic regression analysis.

Setting

Nineteen secondary schools in the province of Otago, New Zealand.

Subjects

Students from school years 9 and 10 (mean age 14·1 (sd 0·7) years).

Results

There was no relationship between dieting and dietary patterns. Those not dieting were 17 % (95 % CI 7, 26 %) more likely to eat lunch and 22 % (95 % CI 3, 37 %) more likely to eat an evening meal on one more weekday than those who were dieting. Those who reported dieting were more likely to report healthiness (OR = 2·18, 95 % CI 1·11, 4·26) as an important factor when choosing food and that eating fruit and vegetables makes you better looking. No sex by dieting interaction was found.

Conclusions

In this cohort, while there was no difference in actual food consumption between dieters and non-dieters, there were significant differences in attitudes to food.
Cooking frequency may enhance survival in Taiwanese elderly
Authors: Chen Rosalind Chia-Yu , Lee Meei-Shyuan , Chang Yu-Hung , Wahlqvist Mark L
Published: May 2012

Objective

To investigate the association between cooking behaviour and long-term survival among elderly Taiwanese.

Design

Cohort study. The duration of follow-up was the interval between the date of interview and the date of death or 31 December 2008, when censored for survivors. Information used included demographics, socio-economic status, health behaviours, cooking frequencies, physical function, cognitive function, nutrition knowledge awareness, eating out habits and food and nutrient intakes. These data were linked to death records. Cox proportional-hazards models were used to evaluate cooking frequency on death from 1999 to 2008 with related covariate adjustments.

Setting

Elderly Nutrition and Health Survey in Taiwan, 1999–2000.

Subjects

Nationally representative free-living elderly people aged ≥65 years (n 1888).

Results

During a 10-year follow-up, 695 participants died. Those who cooked most frequently were younger, women, unmarried, less educated, non-drinkers of alcohol, non-smokers, without chewing difficulty, had spouse as dinner companion, normal cognition, who walked or shopped more than twice weekly, who ate less meat and more vegetables. Highly frequent cooking (>5 times/week, compared with never) predicted survival (hazard ratio (HR) = 0·47; 95 % CI, 0·36, 0·61); with adjustment for physical function, cognitive function, nutrition knowledge awareness and other covariates, HR was 0·59 (95 % CI, 0·41, 0·86). Women benefited more from cooking more frequently than did men, with decreased HR, 51 % v. 24 %, when most was compared with least. A 2-year delay in the assessment of survivorship led to similar findings.

Conclusions

Cooking behaviour favourably predicts survivorship. Highly frequent cooking may favour women more than men.
Investigation of scattering in lunar seismic coda
Authors: Blanchette‐Guertin J.‐F. , Johnson C. L. , Lawrence J. F.
Published: May 2012

We investigate the intrinsic attenuation and scattering properties of the Moon by parameterizing the coda decay of 369 higher‐quality lunar seismograms from 72 events via their characteristic rise and decay times. We investigate any dependence of the decay times on source type, frequency, and epicentral distance. Intrinsic attenuation, scattering, and possible focusing of energy in a near‐surface, low‐velocity layer all contribute to the coda decay. Although it is not possible to quantify the exact contribution of each of these effects in the seismograms, results suggest that scattering in a near‐surface global layer dominates the records of shallow events (∼0–200 km depth), particularly at frequencies above 2 Hz, and for increasing epicentral distance. We propose that the scattering layer is the megaregolith and that energy from shallow sources encounters more scatterers as it travels longer distances in the layer, increasing the coda decay times. A size distribution of ejecta blocks that has more small‐scale than large‐scale scatterers intensifies this effect for increasing frequencies. Deep moonquakes (700–1100 km depth) exhibit no dependence of the decay time on epicentral distance. We suggest that because of their large depths and small amplitudes, deep moonquakes from any distance sample a similar region near a given receiver. Near‐station structure and geology may also control the decay times of local events, as evidenced by two natural impact records. This study provides constraints and testable hypotheses for waveform modeling of the lunar interior that includes the effects of intense scattering and shallow, low‐velocity layers.
Reconciling leaf physiological traits and canopy flux data: Use of the TRY and FLUXNET databases in the Community Land Model version 4
Authors: Bonan Gordon B. , Oleson Keith W. , Fisher Rosie A. , Lasslop Gitta , Reichstein Markus
Published: May 2012

The Community Land Model version 4 overestimates gross primary production (GPP) compared with estimates from FLUXNET eddy covariance towers. The revised model of Bonan et al. (2011) is consistent with FLUXNET, but values for the leaf‐level photosynthetic parameterVcmaxthat yield realistic GPP at the canopy‐scale are lower than observed in the global synthesis of Kattge et al. (2009), except for tropical broadleaf evergreen trees. We investigate this discrepancy betweenVcmaxand canopy fluxes. A multilayer model with explicit calculation of light absorption and photosynthesis for sunlit and shaded leaves at depths in the canopy gives insight to the scale mismatch between leaf and canopy. We evaluate the model with light‐response curves at individual FLUXNET towers and with empirically upscaled annual GPP. Biases in the multilayer canopy with observedVcmaxare similar, or improved, compared with the standard two‐leaf canopy and its lowVcmax, though the Amazon is an exception. The difference relates to light absorption by shaded leaves in the two‐leaf canopy, and resulting higher photosynthesis when the canopy scaling parameterKn is low, but observationally constrained. Larger Kndecreases shaded leaf photosynthesis and reduces the difference between the two‐leaf and multilayer canopies. The low modelVcmaxis diagnosed from nitrogen reduction of GPP in simulations with carbon‐nitrogen biogeochemistry. Our results show that the imposed nitrogen reduction compensates for deficiency in the two‐leaf canopy that produces high GPP. Leaf trait databases (Vcmax), within‐canopy profiles of photosynthetic capacity (Kn), tower fluxes, and empirically upscaled fields provide important complementary information for model evaluation.
An in‐situ record of major environmental transitions on early Mars at Northeast Syrtis Major
Authors: Ehlmann Bethany L. , Mustard John F.
Published: May 2012

The Noachian‐Hesperian transition on Mars was a period marked by changes in volcanic processes and styles of aqueous alteration. Understanding the timing and nature of environmental change requires the exploration of units recording both sets of processes. Herein, we report the compositional stratigraphy of distinctive Noachian to Hesperian units along the northeastern margin of the Syrtis Major volcanic flows. A layered, polyhydrated sulfate‐bearing unit with jarosite ridges has been discovered beneath the Syrtis Major lava flows and above the regionally‐extensive stratigraphy of Noachian plains units reported previously. Sequential clay‐, carbonate‐, and sulfate‐bearing units formed in‐situ and record a transition from alkaline pH to acidic pH waters. The sequence is chronologically bookended by the Isidis impact and Syrtis Major flows, and is one of the most temporally‐constrained and well‐preserved stratigraphic sections from early Mars available for landed exploration.
Looking for evidence of mixing in the solar wind from 0.31 to 0.98 AU
Authors: Borovsky Joseph E.
Published: May 2012

To determine the efficacy of turbulence in the solar wind, the amount of mixing of the solar wind plasma is quantified. If magnetohydrodynamic turbulence in the solar wind acts as does Navier‐Stokes turbulence, the chunk mixture of scalar quantities in the solar wind plasma should evolve with time. In particular, (1) the sizes of plasma chunks should decrease with distance from the Sun owing to the stretching and folding action of turbulence and (2) the occurrence distributions of passive‐scalar values in the plasma should narrow with distance from the Sun owing to homogenization. The evolution of the chunk mix is studied through the use of interface‐crossing statistics. Using Helios 1 and Helios 2 slow‐solar wind measurements from 0.31 to 0.98 AU, temporal jumps in the proton number density, proton specific entropy, and proton beta are used to locate plasma interfaces in the solar wind and the plasma chunk sizes are determined from the distances between the plasma interfaces. No evidence for the evolution of the chunk‐size distribution is seen, indicating an absence of mixing in the solar wind. The distribution of plasma density broadens by 11% with distance, the distribution of proton flux stays constant, while the distribution of proton specific entropy narrows by 14%; collectively the three distributions do not show clear evidence for evolution toward homogeneity, hence they do not show clear evidence for mixing. Implications of the lack of evidence for mixing in the solar wind are discussed.
Evaluating austral summer mixed‐layer response to surface wave–induced mixing in the Southern Ocean
Authors: Huang Chuan Jiang , Qiao Fangli , Shu Qi , Song Zhenya
Published: May 2012

Three ocean general circulation models and a climate model are employed to evaluate the influences of the nonbreaking surface wave–induced mixing on the austral summer (December‐January‐February) mixed layer in the Southern Ocean. These models use either the Mellor‐Yamada turbulence closure scheme or the K profile parameterization scheme. The numerical results show that the nonbreaking surface wave–induced mixing can reduce sea surface temperature and increase subsurface temperature of the upper ocean, which can deepen the upper ocean mixed layer. For these four models, austral summer mixed‐layer depths in the cases with the wave‐induced mixing deepen by 6.2–21.5 m than those without in the Southern Ocean (30°S–65°S), much closer to the observation. These results indicate that incorporation of the wave‐induced mixing can improve the simulation of the austral summer upper mixed layer in the Southern Ocean. Although the responses of four models are different, all simulation results show notable improvements, which may imply that the nonbreaking surface wave–induced mixing is an indispensable physical process for ocean and climate models.
Seasonal variation of upwelling in the Alaskan Beaufort Sea: Impact of sea ice cover
Authors: Schulze Lena M. , Pickart Robert S.
Published: May 2012

Data from a mooring array deployed from August 2002 to September 2004 are used to characterize differences in upwelling near the shelf break in the Alaskan Beaufort Sea due to varying sea ice conditions. The record is divided into three ice seasons: open water, partial ice, and full ice. The basic response is the same in each of the seasons. Roughly 8 h after the onset of easterly winds the shelf break jet reverses, followed approximately 10 h later by upwelling of saltier water which is cold near the shelf break (Pacific Winter Water) and warm at depth (Atlantic Water). The secondary circulation at the outer shelf is, to first order, consistent with a two‐dimensional Ekman balance of offshore flow in the upper layer and onshore flow at depth. There are, however, important seasonal differences in the upwelling. Overall the response is strongest in the partial ice season and weakest in the full ice season. It is believed that these differences are dictated by the degree to which wind stress is transmitted through the pack‐ice, as the strength of the wind‐forcing was comparable over the three seasons. An EOF‐based upwelling index is constructed using information about the primary flow, secondary flow, and hydrography. The ability to predict upwelling using the wind record alone is explored, which demonstrates that 90% of easterly wind events exceeding 9.5 m s−1 drive significant upwelling. During certain periods the ice cover on the shelf became landfast, which altered the upwelling and circulation patterns near the shelf break.
Time domain waveform and azimuth variation of ionospherically reflected VLF/LF radio emissions from lightning
Authors: Jacobson Abram R. , Shao Xuan‐Min , Lay Erin
Published: May 2012

The Earth's geomagnetic field can, in principle, cause significant magnetic‐azimuth variations of the lower ionosphere's reflection of 2–150 kHz radio waves emitted by lightning. There has been little published work on this azimuth variation, either modeled or observational. We use broadband emissions from negative cloud‐to‐ground lightning strokes to study the azimuthal variations systematically. The data are from the Los Alamos Sferic Array, operating in the United States' southern Great Plains during 2005. We compare the observations to a model of lower‐ionosphere reflection of radio waves. The model recapitulates the basic features of the time domain reflection waveforms rather well, except at the lowest frequencies. The model transfer function describing the vertical electric field at the receiver is symmetric about 90° magnetic and about 270° magnetic. Two noteworthy features of the azimuth variation are both predicted by the model, and seen in the data: First, at the lowest frequencies (<30 kHz) there is enhanced reflection for eastward propagation, relative to westward propagation. Second, at the higher frequencies (>50 kHz) there is an opposite enhancement, of the reflection for westward propagation, relative to eastward propagation. The westward enhancement at >50 kHz depends sensitively on range and is most evident in nighttime conditions, while the eastward enhancement at <30 kHz occurs at all ranges studied. Range‐dependent frequency modulations of the transfer function are the least for magnetic northward propagation (duplicated by magnetic southward).
A tribute to the ERC—long live basic research
Authors: Hanski Ilkka
Published: May 2012

In the five years since its creation, the European Research Council has had a major influence on the support for and quality of basic research in Europe. It does not, however, solve the underlying problem that basic research remains under‐appreciated.