bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational thermochemistry of glycolaldehyde
Authors: Bleda Erdi A. , Yavuz Ilhan , Altun Zikri , Trindle Carl
Published: June 2012

We use a variant of the focal point analysis to refine estimates of the relative energies of the four low‐energy torsional conformers of glycolaldehyde. The most stable form is the cis‐cis structure which enjoys a degree of H‐bonding from hydroxyl H to carbonyl O; here dihedral angles τ1 (OCCO) and τ2 (CCOH) both are zero. We optimized structures in both CCSD(T)/aug‐cc‐pVDZ and aug‐cc‐pVTZ; the structures agree within 0.01 Å for bond lengths and 1.0 degrees for valence angles, but the larger basis brings the rotational constants closer to experimental values. According to our extrapolation of CCSD(T) energies evaluated in basis sets ranging to aug‐cc‐pVQZ the trans‐trans form (180°, 180°) has a relative energy of 12.6 kJ/mol. The trans‐gauche conformer (160°, ±75°) is situated at 13.9 kJ/mol and the cis‐trans form (0°, 180°) at 18.9 kJ/mol. Values are corrected for zero point vibrational energy by MP2/aug‐cc‐pVTZ frequencies. Modeling the vibrational spectra is best accomplished by MP2/aug‐cc‐pVTZ with anharmonic corrections. We compute the Watsonian parameters that define the theoretical vibrational‐rotational spectra for the four stable conformers, to assist the search for these species in the interstellar medium. Six transition states are located by G4 and CBS‐QB3 methods as well as extrapolation using energies for structures optimized in CCSD(T)/aug‐cc‐pVDZ structures. We use two isodesmic reactions with two well‐established thermochemical computational schemes G4 and CBS‐QB3 to estimate energy enthalpy and Gibbs energy of formation as well as the entropy of the gas phase system. Our extrapolated electronic energies of species appearing in the isodesmic reactions produce independent values of thermodynamic quantities consistent with G4 and CBS‐QB3. © 2013 Wiley Periodicals, Inc.
Constructing protein nano‐fiber and estimation of the electronic state around metal ions
Authors: Komatsu Yu , Fukuda Masaki , Yamada Hironao , Kawamoto Shuhei , Miyakawa Takeshi , Morikawa Ryota , Takasu Masako , Yokojima Satoshi , Akanuma Satoshi , Yamagishi Akihiko
Published: June 2012

We aim to construct a nano‐fiber using proteins by mixing two kinds of proteins. The binding sites are expected to be formed between two α‐helices of one protein and two α‐helices of another protein. As model proteins, we use Lac repressor four helix protein (LARFH), sulerythrin, and 3‐isopropylmalate dehydrogenase. With these proteins, we performed molecular dynamics (MD) simulations with a coarse‐grained (CG) model. In MD simulations with the CG model for LARFH, we found that the molecules approached faster in the system where the mutant protein with positively charged amino acids was placed with the mutant protein with negatively charged amino acids than in the system containing two wild‐type protein molecules. In the system with the variants, the number of contact interfaces with the positive variant‐negative variant combination after 150 ns simulation is larger than that with the positive–positive variants combination or the negative–negative variants combination. Sulerythrin has two pairs of Fe2+ and Zn2+. Electronic structure calculation was performed around metal ions in sulerythrin. By electronic structure calculation for sulerythrin around metal ions, the electric charge and spin density were estimated. © 2012 Wiley Periodicals, Inc.
Client cloud Web service: reducing traffic consumption
Authors: Paik Jung Ha , Cho Kwantae , Jung Boo Geum , Lee Dong Hoon
Published: June 2012

The availability of the Web service has been exposed to several threats such as distributed denial‐of‐service attack, which is not an unfamiliar terminology anymore. Sustaining availability against various attacks becomes the critical issue for high‐profile Web sites. In this paper, we propose a novel architecture providing Web service among client, called client cloud Web service, by utilizing resources of clients to enhance the availability. Client cloud Web service can be easily integrated into the current Internet protocol suite by providing a transparent layer in the middle of Hypertext Transfer Protocol layer and Transmission Control Protocol/Internet Protocol layer. It is shown by simulations that the proposed architecture can efficiently reduce the traffic when both the size of Web items and the number of requests from clients increase. Copyright © 2012 John Wiley & Sons, Ltd.
More efficient CCA‐secure unidirectional proxy re‐encryption schemes without random oracles
Authors: Wang Hongbing , Cao Zhenfu
Published: June 2012

In this paper, we present a more efficient chosen‐ciphertext secure proxy re‐encryption scheme in the standard model with less ciphertext size and without any strong unforgeable one‐time signature. Our scheme is unidirectional and single‐hop. The security of our scheme is under the reasonable complexity assumption—the decisional bilinear Diffie–Hellman assumption in bilinear groups. There are no proxy re‐encryption schemes achieving chosen‐ciphertext security in the standard model without a strong unforgeable one‐time signature in the literature. Copyright © 2012 John Wiley & Sons, Ltd.
Secure SIP authentication scheme supporting lawful interception
Authors: Pu Qiong , Wang Jian , Wu Shuhua
Published: June 2012

The session initiation protocol (SIP) is the most widely used signaling protocol for creating, modifying, and terminating multimedia sessions in an Internet Protocol‐based telephony environment. Recently, Arshad et al. proposed an authentication scheme based on elliptic curve cryptosystems for SIP. In this paper, we first show that their scheme is vulnerable to the password‐guessing attack. Thereafter, we propose a new authentication and key agreement scheme for SIP, which is immune to the presented attacks. Our scheme achieves provable security and, yet, is efficient. Moreover, we also provide an extended scheme capable of protecting media stream's privacy even against SIP servers while supporting lawful interception, which is inevitably required for protecting the national security or for detecting the criminal evidence. Copyright © 2012 John Wiley & Sons, Ltd.
Research and implementation of M2M smart home and security system
Authors: Jiang Ting , Yang Ming , Zhang Yi
Published: June 2012

Over recent years, the concept of Internet of Things has been put forward and undergone gradual progress. Machine to machine (M2M) technology, as the most prevalent application form of Internet of Things now, is widely used in various fields, among which smart home takes on tremendous market potential in virtue of its intimate relationship with human life. This paper endeavors to propose the smart home and security system, an M2M application system based on wireless networks, by combining wireless sensor network, mobile communication network, and the Internet together and briefly introduces the architecture, function, interface, identity addressing, and security mechanism of this system. Copyright © 2012 John Wiley & Sons, Ltd.
Thermal stability of high‐κ oxides on SiO2/Si or SixNy/SiO2/Si for charge‐trapping nonvolatile memories
Authors: Lamperti A. , Cianci E. , Salicio O. , Lamagna L. , Spiga S. , Fanciulli M.
Published: June 2012

High dielectric constant (high‐κ) oxides are foreseen replacement materials in innovative metal–oxide–semiconductor devices and memory capacitors. In particular, when considering nonvolatile memories, the charge‐trapping concept appears to be a promising solution for flash‐type floating gate replacement. Among the high‐κ oxide properties to be considered, it is essential to study the compatibility towards the integration of these materials in a complementary metal–oxide–semiconductor process, in particular to control the stack integrity and any onset of diffusion phenomena upon thermal treatments at temperatures higher than 1000 °C. Here, we report on the results obtained from time‐of‐flight secondary ion mass spectrometry depth profiling of stacks on the basis of high‐κ/SiO2/Si, integrating HfO2, ZrO2, or DyScOx as charge‐trapping layer or high‐κ/SixNy/SiO2/Si integrating DyScOx as control (blocking) oxide. The high‐κ oxides are all grown by atomic layer deposition. We will discuss the role of the different substrate/oxide coupling in preserving the stack and propose the better combinations in terms of thermal stability. Copyright © 2012 John Wiley & Sons, Ltd.
Threat‐oriented security framework in risk management using multiagent system
Authors: Bedi Punam , Gandotra Vandana , Singhal Archana , Narang Himanshi , Sharma Sumit
Published: June 2012

Present day sophisticated and innovative attacks have resulted in exponentially increasing security problems. This paper therefore presents a three‐phased threat‐oriented security model to meet the above security challenges as a part of proactive risk management. This model is based on a spiral process for software development because it is a risk driven approach and provides an incremental method for a progressively growing system with decreasing risk. Integration of threat management during the development process in the proposed work provides necessary security cover against both unforeseen and known threats. Identification of these threats has been made possible by fusion of a threat modeling process and research honeytokens in conjunction with a statistical model in the first phase. Necessary security measures to mitigate the above identified threats have been adopted in the second phase using multiagent system planning. Risk reduction as a result of adoption of countermeasures has been evaluated in the third phase using meta‐agents in association with fuzzy logic in a multiagent environment. The proposed proactive measures of this model have been demonstrated with a case study on ‘Online Banking’ to show its feasibility and has been implemented using Java Agent Development Environment, Apache Tomcat Server, with MySQL Server at the backend. Copyright © 2012 John Wiley & Sons, Ltd.
Targeting p90 Ribosomal S6 Kinase Eliminates Tumor-Initiating Cells by Inactivating Y-Box Binding Protein-1 in Triple-Negative Breast Cancers
Authors: Stratford Anna L. , Reipas Kristen , Hu Kaiji , Fotovati Abbas , Brough Rachel , Frankum Jessica , Takhar Mandeep , Watson Peter , Ashworth Alan , Lord Christopher J. , Lasham Annette , Print Cristin G. , Dunn Sandra E.
Published: June 2012

Y-box binding protein-1 (YB-1) is the first reported oncogenic transcription factor to induce the tumor-initiating cell (TIC) surface marker CD44 in triple-negative breast cancer (TNBC) cells. In order for CD44 to be induced, YB-1 must be phosphorylated at S102 by p90 ribosomal S6 kinase (RSK). We therefore questioned whether RSK might be a tractable molecular target to eliminate TICs. In support of this idea, injection of MDA-MB-231 cells expressing Flag-YB-1 into mice increased tumor growth as well as enhanced CD44 expression. Despite enrichment for TICs, these cells were sensitive to RSK inhibition when treated ex vivo with BI-D1870. Targeting RSK2 with small interfering RNA (siRNA) or small molecule RSK kinase inhibitors (SL0101 and BI-D1870) blocked TNBC monolayer cell growth by ∼100%. In a diverse panel of breast tumor cell line models RSK2 siRNA predominantly targeted models of TNBC. RSK2 inhibition decreased CD44 promoter activity, CD44 mRNA, protein expression, and mammosphere formation. CD44+ cells had higher P-RSKS221/227, P-YB-1S102, and mitotic activity relative to CD44− cells. Importantly, RSK2 inhibition specifically suppressed the growth of TICs and triggered cell death. Moreover, silencing RSK2 delayed tumor initiation in mice. In patients, RSK2 mRNA was associated with poor disease-free survival in a cohort of 244 women with breast cancer that had not received adjuvant treatment, and its expression was highest in the basal-like breast cancer subtype. Taking this further, we report that P-RSKS221/227 is present in primary TNBCs and correlates with P-YB-1S102 as well as CD44. In conclusion, RSK2 inhibition provides a novel therapeutic avenue for TNBC and holds the promise of eliminating TICs.
Recognition of peak oil
Authors: Campbell C.J.
Published: June 2012

Oil and gas have provided much of the energy to drive the Industrial Revolution over the past two centuries, but they are finite resources formed in the geological past, which means they are subject to depletion. The peak of world oil discovery in the 1960s must deliver a corresponding peak of production. The onset of the decline of this critical energy source will likely have far‐reaching social, economic, and political consequences. This turning point in history would be self‐evident but for lax reporting standards and ambiguous definitions. © 2012 John Wiley & Sons, Ltd.

This article is categorized under:

Fossil Fuels > Economics and Policy

Fossil Fuels > Systems and Infrastructure
Spatially homogeneous Lifshitz black holes in five dimensional higher derivative gravity
Authors: Liu Yan
Published: June 2012

Abstract

We consider spatially homogeneous Lifshitz black hole solutions in five dimensional higher derivative gravity theories, which can be possible near horizon geometries of some systems that are interesting in the framework of gauge/gravity duality. We show the solutions belonging to the nine Bianchi classes in the pure R
2 gravity. We find that these black holes have zero entropy at non-zero temperatures and this property is the same as the case of BTZ black holes in new massive gravity at the critical point. In the most general quadratic curvature gravity theories, we find new solutions in Bianchi Type I and Type IX cases.
Applications of real number theorem proving in PVS
Authors: Gottliebsen Hanne , Hardy Ruth , Lightfoot Olga , Martin Ursula
Published: June 2012

Real number theorem proving has many uses, particularly for verification of safety critical systems and systems for which design errors may be costly. We discuss a chain of developments building on real number theorem proving in PVS. This leads from the verification of aspects of an air traffic control system, through work on the integration of computer algebra and automated theorem proving to a new tool, NRV, first presented here that builds on the capabilities of Maple and PVS to provide a verified and automatic analysis of Nichols plots. This automates a standard technique used by control engineers and greatly improves assurance compared with the traditional method of visual inspection of the Nichols plots.
Microsatellite Instability Is Associated With a Better Prognosis for Gastric Cancer Patients After Curative Surgery
Authors: Fang Wen‐Liang , Chang Shih‐Ching , Lan Yuan‐Tzu , Huang Kuo‐Hung , Chen Jen‐Hao , Lo Su‐Shun , Hsieh Mao‐Chih , Li Anna Fen‐Yau , Wu Chew‐Wun , Chiou Shih‐Hwa
Published: June 2012

Background

Microsatellite instability (MSI) is one of the leading mechanisms for the carcinogenesis of gastric cancer. Its prognostic value is controversial.

Methods

Between May 1988 and Oct 2003, a total of 214 gastric cancer patients undergoing curative surgery were enrolled, and their MSI statuses were classified as MSI‐H (high) or MSI‐L/S (low/stable). The clinicopathologic characteristics of MSI‐H and MSI‐L/S gastric cancers were compared.

Results

The MSI‐H tumors accounted for 11.7 % (n = 25) of the 214 total gastric cancers. Although not statistically significant, the MSI‐H gastric cancers were more frequently located in the lower third of the stomach (64 % vs. 49.2 %) and were more often the intestinal type (72 % vs. 61.4 %) compared to the MSI‐L/S gastric cancers. The MSI‐H gastric cancers had a significantly better 5‐year overall survival (OS) rate (68 % vs. 47.6 %, p = 0.030) and a trend of a better 3‐year disease‐free survival rate (71.8 % vs. 55.2 %, p = 0.076) compared to the MSI‐L/S gastric cancers. A multivariate analysis revealed that pathologic TNM stage and MSI status were the independent prognostic factors for OS after curative surgery.

Conclusions

Compared to MSI‐L/S tumors, MSI‐H tumors are associated with a better OS rate for gastric cancer patients after R0 resection.
Guided Treatment Improves Outcome of Patients with Enterocutaneous Fistulas
Authors: Visschers Ruben G. J. , van Gemert Wim G. , Winkens Bjorn , Soeters Peter B. , Olde Damink Steven W. M.
Published: June 2012

Background

The present study was designed to evaluate the effects of guided treatment of patients with an enterocutaneous fistula and to evaluate the effect of prolonged period of convalescence on outcome.

Methods

All consecutive patients with an enterocutaneous fistula treated between 2006 and 2010 were included in this study. Patient information was gathered prospectively. Treatment of patients focused on sepsis control, optimization of nutritional status, wound care, establishing the anatomy of the fistula, timing of surgery, and surgical principles. Outcome included spontaneous and surgical closure, mortality, and postoperative recurrence. The relationship between period of convalescence and recurrence rate was determined by combining the present prospective cohort with a historical cohort from our group.

Results

Between 2006 and 2010, 79 patients underwent focused treatment for enterocutaneous fistula. Cox regression analysis showed that period of convalescence related significantly with recurrence of the fistula (hazard ratio 0.99; 95 % confidence interval 0.98–0.999; p = 0.04). Spontaneous closure occurred in 23 (29 %) patients after a median period of convalescence of 39 (range 7–163) days. Forty‐nine patients underwent operative repair after median period of 101 (range 7–374) days and achieved closure in 47 (96 %). Overall, eight patients (10 %) died.

Conclusions

Prolonging period of convalescence for patients with enterocutaneous fistulas improves spontaneous closure and reduces recurrence rate.
SH3 domains come of age
Authors: Kay Brian K.
Published: June 2012

With the sequencing of an eukaryotic genome, it is possible to inventory the predicted proteome for proteins that carry one or more Src Homology 3 (SH3) domains. Due to the current ease of cloning and gene synthesis, these short domains can be readily overexpressed and manipulated for the purpose of characterizing their specificity and affinity for peptide ligands, as well as solving the three‐dimensional structures of the domains. This information can be used to predict and confirm their cellular interacting partners, in the effort to understand the function of a eukaryotic protein by focusing on its SH3 domain. Finally, capitalizing on our mature understanding about protein–protein interacting modules, like the SH3 domain, it is possible to use directed evolution to enhance or change the specificity and affinity of an SH3 domain for the purpose of creating reagents to be used in biochemical purification or cell perturbation studies.
Consumption of dairy products and associations with incident diabetes, CHD and mortality in the Whitehall II study
Authors: Soedamah-Muthu Sabita S. , Masset Gabriel , Verberne Lisa , Geleijnse Johanna M. , Brunner Eric J.
Published: June 2012

Few prospective studies have examined the effects of different types of dairy food on the risks of type 2 diabetes, CHD and mortality. We examined whether intakes of total dairy, high-fat dairy, low-fat dairy, milk and fermented dairy products were related to these outcomes in the Whitehall II prospective cohort study. At baseline, dairy consumption was assessed by FFQ among 4526 subjects (72 % men) with a mean age 56 (sd 6) years. Death certificates and medical records were used to ascertain CHD mortality and non-fatal myocardial infarction. Incident diabetes was detected by the oral glucose tolerance test or self-report. Incidence data were analysed using Cox proportional hazards models, adjusted for lifestyle and dietary factors. During approximately 10 years of follow-up, 273 diabetes, 323 CHD and 237 all-cause mortality cases occurred. In multivariable models, intakes of total dairy and types of dairy products were not significantly associated with incident diabetes or CHD (all P values for trend >0·1). Fermented dairy products was inversely associated with overall mortality (hazard ratios approximately 0·7 in the middle and highest tertiles; P for trend < 0·01) but not with incident CHD or diabetes (P>0·3). In conclusion, intakes of total dairy and types of dairy products showed no consistent relationship with incident diabetes, CHD or all-cause mortality.
SOCIO-DEMOGRAPHIC FACTORS ASSOCIATED WITH TREATMENT AGAINST SOIL-TRANSMITTED HELMINTH INFECTIONS IN CHILDREN AGED 12–59 MONTHS USING THE HEALTH FACILITY APPROACH ALONE OR COMBINED WITH A COMMUNITY-DIRECTED APPROACH IN A RURAL AREA OF ZAMBIA
Authors: HALWINDI H. , MAGNUSSEN P. , SIZIYA S. , MEYROWITSCH D. W. , OLSEN A.
Published: June 2012

A health facility-based (HF) approach to delivering anthelminthic drugs to children aged 12–59 months in Zambia was compared with an approach where community-directed treatment (ComDT) was added to the HF approach (HF+ComDT). This paper reports on the socio-demographic factors associated with treatment coverage in the HF+ComDT and HF areas after 18 months of implementation. Data were collected by interviewing 288 and 378 caretakers of children aged 12–59 months in the HF+ComDT and HF areas, respectively. Bivariate and multivariate logistic regression analyses were used for data analysis. Statistically significant predictors of a child being treated were: a child coming from the HF+ComDT area, being 12–36 months old, the family having lived in the area for >20 years, coming from a household with only one under-five child and living ≤3 km from the health facility. It is concluded that socio-demographic factors are of public health relevance and affect treatment coverage in both the HF+ComDT and the HF approaches. The implementation and strengthening of interventions like ComDT that bring treatment closer to households will enable more children to have access to treatment.
Hypercyclic composition operators on spaces of real analytic functions
Authors: BONET JOSÉ , DOMAŃSKI PAWEŁ
Published: June 2012

We study the dynamical behaviour of composition operatorsCϕdefined on spaces(Ω) of real analytic functions on an open subset Ω of ℝd. We characterize when such operators are topologically transitive, i.e. when for every pair of non-empty open sets there is an orbit intersecting both of them. Moreover, under mild assumptions on the composition operator, we investigate when it is sequentially hypercyclic, i.e., when it has a sequentially dense orbit. If ϕ is a self map on a simply connected complex neighbourhoodUof ℝ,U≠ ℂ, then topological transitivity, hypercyclicity and sequential hypercyclicity ofCϕ:(ℝ) →(ℝ) are equivalent.
Analyzing the Eyjafjallajökull 2010 eruption using satellite remote sensing, lidar and WRF‐Chem dispersion and tracking model
Authors: Webley P. W. , Steensen T. , Stuefer M. , Grell G. , Freitas S. , Pavolonis M.
Published: June 2012

Volcanic ash forecasting is a critical tool in hazard assessment and operational volcano monitoring. The use of volcanic ash transport and dispersion models allows analysts to determine the future location of ash clouds. In April–May 2010, Eyjafjallajökull in Iceland erupted explosively. Presented here is an evaluation of the volcanic application of the weather research and forecasting in‐line chemistry model (WRF‐Chem) applied to Eyjafjallajökull. The analysis focuses on the first few days of the explosive events, April 14–19. The model simulations are presented along with multiple satellite and ground based tools to compare and validate the results. The WRF‐Chem results showed the ash cloud dispersing toward mainland Europe, with concentrations crossing Europe between 0.5–2.0 mg/m3, centered at 5 km ASL, +/−1 km. Comparisons with satellite volcanic ash retrievals showed a good agreement and ground‐based Light Detection And Ranging (LIDAR) data compared well to the model simulations. The analysis in this manuscript has illustrated the use of WRF‐Chem for volcanic eruptions, with the coupled numerical weather simulation and ash forecasting important to understand the local atmospheric conditions as well as the ash cloud distribution. We show that to fully forecast ash concentrations, to the level of mg's per m3, there is a need for accurate knowledge of the plume height; mass eruption rate; particle size distribution and duration along with a fusion of all data. Then accurate hazard assessments can be performed to limit the impact that dispersing clouds have on the aviation community and population.
Russia sets sights on lunar base
Authors: Showstack Randy
Published: June 2012

Vladimir Popovkin, director of Roscomos, the Russian Federal Space Agency, said the agency is setting its sights on the Moon. “We strongly feel that it is time for us to start working toward being able to establish a permanent base on the Moon,” Popovkin said at a 22 May panel discussion and news briefing held in conjunction with the Global Space Exploration Conference in Washington, D. C. Establishing a goal of lunar exploration does not mean that Roscomos is giving up on other priorities such as exploration of Mars, asteroids, or the moons of Jupiter, Popovkin said. “We have much better chances to come up with very productive and tangible results while concentrating on Moon exploration,” he said, noting the findings of water in polar areas.
White House nominates nuclear commissioner
Authors: Showstack Randy
Published: June 2012

Just 3 days after U.S. Nuclear Regulatory Commission chairman Gregory Jaczko announced his intention to resign (Eos, 93(22), 211, doi:10.1029/2012EO220005, 2012), President Barack Obama nominated Allison Macfarlane to serve out the remainder of Jaczko's term, through June 2013. The White House announced that upon her appointment, Macfarlane would be designated as chair of the commission. Macfarlane is an associate professor of environmental science and policy at George Mason University. A member of the Blue Ribbon Commission on America's Nuclear Future from March 2010 to January 2012, she is also the author of the 2006 book Uncertainty Underground: Yucca Mountain and the Nation's High‐Level Nuclear Waste and is an AGU member.
Call for nominations for 2012 William Kaula Award
Authors: Major Barbara
Published: June 2012

The William Kaula Award recognizes unselfish service to the scientific community through extraordinary dedication to and exceptional efforts on behalf of AGU's publications program. Individuals may be recognized for contributions such as outstanding reviewing, editorial service beyond expectations, or innovative leadership. In even numbered years the Publications Committee selects a recipient, who is recognized at the Editors' Evening at the Fall Meeting and in Eos. The Publications Committee is asking the community to help identify those who are deserving of this award. If you would like to nominate someone, please send an e‐mail to editors_relations@agu.org no later than 15 August 2012. Please outline as clearly as possible why this particular individual is a worthy recipient of the award.
Measuring currents between North Atlantic and Nordic seas
Authors: Balcerak Ernie
Published: June 2012

The fluxes of water from the North Atlantic to the Nordic seas provide a measure of the water that flows into and out of the global ocean as part of the meridional overturning circulation. The meridional overturning circulation, which carries warm water in the Atlantic from the tropics northward and brings cold dense water back southward, is a key part of global ocean circulation and a strong influence on climate; some research has suggested that the meridional overturning circulation could slow down as the global climate warms. Using an acoustic Doppler current profiler mounted in the high seas ferryNorröna to repeatedly measure the currents in the Faroe‐Shetland Channel and over the Iceland‐Faroe Ridge, Rossby and Flagg report on 3 years of weekly measurements that provide a new, accurate measure of the exchange of water between the North Atlantic and Nordic seas. The observations will be useful in understanding the meridional overturning circulation. (Geophysical Research Letters, doi:10.1029/2012GL051269, 2012)
Sources and physicochemical characteristics of fluids along a subduction‐zone megathrust: A geochemical approach using syn‐tectonic mineral veins in the Mugi mélange, Shimanto accretionary complex
Authors: Yamaguchi Asuka , Ujiie Kohtaro , Nakai Shun'ichi , Kimura Gaku
Published: June 2012

The Mugi mélange in the Shimanto accretionary complex, southwest Japan, records faulting and fluid flow patterns at the updip limit of the seismogenic region of the Nankai subduction zone. To characterize the origin and behavior of syn‐tectonic fluids, we investigated the carbon, oxygen, and strontium isotopic compositions, and rare earth element (REE) patterns of syn‐tectonic calcite within veins along fault zones in the mélange, as well as the Sr isotopic compositions and REE patterns of surrounding host rocks. With the exception of intra‐basalt veins formed prior to subduction, the δ13C values of veins range from −10‰ to −19‰, suggesting a mixed carbon source (i.e., marine carbonate and organic matter). The vein‐forming fluids have positive oxygen isotopic compositions (+2‰ to +9‰ (SMOW)) and high 87Sr/86Sr values (0.70794–0.70850), suggesting that the source was rock‐buffered fluids affected both by terrigenous sediments and altered oceanic crust. The veins found in filling the fault zone associated with tectonic underplating have different REE patterns to those of the other veins, implying a difference in physicochemical processes affecting the fault zone near the subduction megathrust.
The structure of Fe‐Ni alloy in Earth's inner core
Authors: Tateno Shigehiko , Hirose Kei , Komabayashi Tetsuya , Ozawa Haruka , Ohishi Yasuo
Published: June 2012

The crystal structure of Fe‐10%Ni was investigated up to 340 GPa and 4700 K, corresponding to the Earth's inner core conditions by synchrotron X‐ray diffraction measurementsin‐situat ultrahigh pressure and temperature in a laser‐heated diamond‐anvil cell. The results show that hexagonal closed‐packed (hcp) structure is stable throughout the experimental conditions investigated with no evidence for a phase transition to body‐centered cubic (bcc) or face‐centered cubic (fcc) phases. The axialc/a ratio of the hcp crystal obtained around 330 GPa has a small temperature dependence similar to the axial ratio of pure Fe. Iron alloy with less than 10% Ni crystallizes to an hcp structure with c/a ratio of ∼1.61 at inner core conditions, although the effect of small amount of light elements remains to be examined by experiments.
The structure and fault activity of the Makran accretionary prism
Authors: Smith Gemma , McNeill Lisa , Henstock Timothy J. , Bull Jon
Published: June 2012

The Makran Subduction Zone has the highest incoming sediment thickness (up to 7.5 km) of any subduction zone. These sediments have formed a wide accretionary prism (∼400 km). Seismicity in the Makran is generally low; however the margin experienced an Mw 8.1 earthquake in 1945 which generated a significant regional tsunami. Seismic reflection data and swath bathymetry data from offshore Pakistan are used to analyze the structure and fault activity of the outer accretionary prism. The outer prism has a simple structure of seaward verging imbricate thrust faults, many continuous for over 100 km along strike. Fault activity is analyzed using basin stratigraphy and fault geometry, revealing a frontal continuously active zone, a central intermittently active zone, and a landward inactive zone. Over 75% of the faults in the seaward ∼70 km of the prism show evidence for recent activity. The décollement occurs within the lower sediment section, but steps onto the top‐basement surface in regions of elevated basement topography. Fault spacing (6 km) and taper (4.5°) are comparable to other margins such as S. Hikurangi, Cascadia and Nankai, suggesting that high sediment input is not leading to an unusual prism structure. The décollement is unreflective, which is unexpected considering other prism characteristics predicting a weak surface, and may suggest a potentially stronger décollement than previously predicted. This study provides a significant advance in our understanding of the structure of an end‐member convergent margin and demonstrates that systematic analyses of accretionary prism structure can help to elucidate subduction zone dynamics with ultimate relevance to seismogenic potential.
Challenges of Postdisaster Intervention in Cultural Context: The Implementation of a Lay Mental Health Worker Project in Postearthquake Haiti
Authors: James Leah Emily , Noel John Roger , Favorite Todd Knowlton , Jean Jacques Solon
Published: June 2012

Recent disasters have incited controversy regarding whether and how Western psychology can contribute to postdisaster mental health care across cultures. Drawing from experience implementing a Haitian–United States collaborative intervention for displaced earthquake survivors in Port-au-Prince, we propose that when a model is culturally compatible, participants may benefit from both indigenous and Western psychological perspectives simultaneously, even if these approaches are not entirely congruent. We describe the theoretical basis and development of this train-the-trainer lay mental health worker project, called Soulaje Lespri Moun (Relief for the Spirit), and outline its efforts to present empirically informed psychological content to residents of camps for internally displaced peoples using a culturally appropriate and community-focused framework. We detail the evolution of this project to accommodate shifting conditions postearthquake, as well as challenges faced and ongoing evaluation efforts.
Influence of geogenic factors on microbial communities in metallogenic Australian soils
Authors: Reith Frank , Brugger Joel , Zammit Carla M , Gregg Adrienne L , Goldfarb Katherine C , Andersen Gary L , DeSantis Todd Z , Piceno Yvette M , Brodie Eoin L , Lu Zhenmei , He Zhili , Zhou Jizhong , Wakelin Steven A
Published: June 2012

Links between microbial community assemblages and geogenic factors were assessed in 187 soil samples collected from four metal-rich provinces across Australia. Field-fresh soils and soils incubated with soluble Au(III) complexes were analysed using three-domain multiplex-terminal restriction fragment length polymorphism, and phylogenetic (PhyloChip) and functional (GeoChip) microarrays. Geogenic factors of soils were determined using lithological-, geomorphological- and soil-mapping combined with analyses of 51 geochemical parameters. Microbial communities differed significantly between landforms, soil horizons, lithologies and also with the occurrence of underlying Au deposits. The strongest responses to these factors, and to amendment with soluble Au(III) complexes, was observed in bacterial communities. PhyloChip analyses revealed a greater abundance and diversity of Alphaproteobacteria (especially Sphingomonas spp.), and Firmicutes (Bacillus spp.) in Au-containing and Au(III)-amended soils. Analyses of potential function (GeoChip) revealed higher abundances of metal-resistance genes in metal-rich soils. For example, genes that hybridised with metal-resistance genes copA, chrA and czcA of a prevalent aurophillic bacterium, Cupriavidus metallidurans CH34, occurred only in auriferous soils. These data help establish key links between geogenic factors and the phylogeny and function within soil microbial communities. In particular, the landform, which is a crucial factor in determining soil geochemistry, strongly affected microbial community structures.
Coupling between quantum Hall state and electromechanics in suspended graphene resonator
Authors: Singh Vibhor , Irfan Bushra , Subramanian Ganesh , Solanki Hari S. , Sengupta Shamashis , Dubey Sudipta , Kumar Anil , Ramakrishnan S. , Deshmukh Mandar M.
Published: June 2012

Using graphene resonator, we perform electromechanical measurements in quantum Hall regime to probe the coupling between a quantum Hall (QH) system and its mechanical motion. Mechanically perturbing the QH state through resonance modifies the DC resistance of the system and results in a Fano-lineshape due to electronic interference. Magnetization of the system modifies the resonator’s equilibrium position and effective stiffness leading to changes in resonant frequency. Our experiments show that there is an intimate coupling between the quantum Hall state and mechanics—electron transport is affected by physical motion and in turn the magnetization modifies the electromechanical response.
Nonlinear, electrocatalytic swimming in the presence of salt
Authors: Sabass Benedikt , Seifert Udo
Published: June 2012

A small, bimetallic particle in a hydrogen peroxide solution can propel itself by means of an electrocatalytic reaction. The swimming is driven by a flux of ions around the particle. We model this process for the presence of a monovalent salt, where reaction-driven proton currents induce salt ion currents. A theory for thin diffuse layers is employed, which yields nonlinear, coupled transport equations. The boundary conditions include a compact Stern layer of adsorbed ions. Electrochemical processes on the particle surface are modeled with a first order reaction of the Butler-Volmer type. The equations are solved numerically for the swimming speed. An analytical approximation is derived under the assumption that the decomposition of hydrogen peroxide occurs mainly without inducing an electric current. We find that the swimming speed increases linearly with hydrogen peroxide concentration for small concentrations. The influence of ion diffusion on the reaction rate can lead to a concave shape of the function of speed vs. hydrogen peroxide concentration. The compact layer of ions on the particle diminishes the reaction rate and consequently reduces the speed. Our results are consistent with published experimental data.
Electronic excitation spectra of radical anions of cyanoethylenes and cyanobenzenes: Symmetry adapted cluster–configuration interaction study
Authors: Nakashima Hiroyuki , Shida Tadamasa , Nakatsuji Hiroshi
Published: June 2012

Electronic excitation spectra of the radical anions of cyanoethylenes (trans-dicyanoethylene and tetracyanoethylene) and cyanobenzenes (1,2-dicyanobenzene: o-DCNB, 1,3-dicyanobenzene: m-DCNB, and 1,4-dicyanobenzene: p-DCNB) were studied by the symmetry adapted cluster–configuration interaction (SAC-CI) method. Theoretical calculations predicted positive electron affinities for all the molecules in good agreement with the experimental observations. Electronic excitation spectra of open-shell radicals is a topic that has not been studied as much as such spectra of closed-shell molecules, but this can be easily addressed using SAC-CI theory. The present paper systematically describes the calculation procedures for radical anions by investigating several basis sets, including anion diffuse and Rydberg functions. The calculated excitation energies were in good agreement with the experimental UV/NIR (near infrared region) spectra, which had been observed by one of the present authors in 2-methyltetrahydrofuran matrix frozen to transparent glassy solids at 77 K. For p-DCNB, the SAC-CI theoretical spectrum agreed particularly well with the experimental spectrum. An extremely weak π*(SOMO) – π* excitation at 1.41 eV predicted in the present work, but had been overlooked in the previous experimental spectrum published in 1988, was confirmed to be real by a careful re-examination of the old spectrum.
Predicting patchy particle crystals: Variable box shape simulations and evolutionary algorithms
Authors: Bianchi Emanuela , Doppelbauer Günther , Filion Laura , Dijkstra Marjolein , Kahl Gerhard
Published: June 2012

We consider several patchy particle models that have been proposed in literature and we investigate their candidate crystal structures in a systematic way. We compare two different algorithms for predicting crystal structures: (i) an approach based on Monte Carlo simulations in the isobaric-isothermal ensemble and (ii) an optimization technique based on ideas of evolutionary algorithms. We show that the two methods are equally successful and provide consistent results on crystalline phases of patchy particle systems.
Dynamic structure of methane/n-nonane clusters during nucleation and growth
Authors: Braun Stephan , Kraska Thomas
Published: June 2012

We report results on nucleation, growth, and structure formation of methane/n-nonane clusters in an expanding system investigated by molecular dynamics simulation. From bulk phase equilibria data, it is expected that the concentration of the less volatile substance n-nonane in the clusters is very high. However, analyses of experimental data in the literature suggest somewhat higher methane content at onset of nucleation. Our simulations show that the methane mole fraction is actually very high and increases even further at the beginning of the cluster growth. On the other hand, in this transient state after nucleation the methane mole fraction in the cluster core decreases, leaving a n-nonane rich core, i.e., we observe the phase separation inside the growing cluster. Methane is squeezed out from the core to the surface and then evaporates from the surface shell during expansion of the system.
Ultrafast laser induced breakdown spectroscopy of electrode/electrolyte interfaces
Authors: Zorba Vassilia , Syzdek Jaroslaw , Mao Xianglei , Russo Richard E. , Kostecki Robert
Published: June 2012

Direct chemical analysis of electrode/electrolyte interfaces can provide critical information on surface phenomena that define and control the performance of Li-based battery systems. In this work, we introduce the use of ex situ femtosecond laser induced breakdown spectroscopy to probe compositional variations within the solid electrolyte interphase (SEI) layer. Nanometer-scale depth resolution was achieved for elemental and molecular depth profiling of SEI layers formed on highly oriented pyrolytic graphite electrodes in an organic carbonate-based electrolyte. This work demonstrates the unique ability of ultrafast laser spectroscopy as a highly versatile, light element-sensitive technique for direct chemical analysis of interfacial layers in electrochemical energy storage systems.
Correlation of the temperature coefficient of resistivity for doped manganites to the transition temperature, polaron binding energy, and magnetic order
Authors: Wang L. M. , Wang Chih-Yi , Tseng Chun-Chin
Published: June 2012

Based on the phase-coexistence transport model, an expression for the temperature coefficient of resistivity (TCR) behavior in doped manganites is proposed. The derived maximum TCR value (TCRmax), being related to polaron binding energy, transition temperature, and disorder in doped manganites, describes the observed “universal law” that the TCRmax is decreased, when TC increases. The calculated results are strongly supported by experiments and are analyzed within the framework of a microscopic transport mechanism. Correlation of the proposed TCR behavior to the transport parameters creates an opportunity to improve the TCRmax value in doped manganites, for uncooled bolometric applications.
Pressure-induced exchange bias effect in phase-separated CaMn0.9Ru0.1O3
Authors: Fita I. , Markovich V. , Wisniewski A. , Puzniak R. , Martin C. , Varyukhin V. N. , Gorodetsky G.
Published: June 2012

Strong enhancement of exchange bias (EB) effect in phase-separated CaMn0.9Ru0.1O3 manganite with ferromagnetic phase heavily suppressed under pressure was observed in the measurements of field-cooled magnetization hysteresis loop. It was found that both EB field HE and normalized remanence asymmetry pronouncedly increase with increasing pressure P, enlarging by one order of magnitude at P = 10 kbar. In contrast, the coercive field HC shows a non-monotonic variation with pressure, reaching a maximum value at around 5 kbar. Such unusual HC(P) dependence may be explained by transformation from multi-domain to single-domain state in a system of ferromagnetic (FM) size-variable particles. Comparison of HE(P) with HC(P) data indicates remarkable enhancement of EB with decrease in HC in the pressure range between 5 and 10 kbar. It is argued that a strong increase of HE under pressure is attributed to the suppression of FM phase, i.e., to the decrease in size of FM clusters embedded in antiferromagnetic matrix. Presented results show that the EB effect can be tuned in a wide range by external pressure.
Carbon nanotube-based charge-controlled speed-regulating nanoclutch
Authors: Zhang Zhong-Qiang , Ye Hong-Fei , Liu Zhen , Ding Jian-Ning , Cheng Guang-Gui , Ling Zhi-Yong , Zheng Yong-Gang , Wang Lei , Wang Jin-Bao
Published: June 2012

In this paper, a carbon nanotube-based charge-controlled speed-regulating nanoclutch (CNT-CC-SRNC), composed of an inner carbon nanotube (CNT), an outer CNT, and the water confined between the two CNT walls, is proposed by utilizing electrowetting-induced improvement of the friction at the interfaces between water and CNT walls. As the inner CNT is the driving axle, molecular dynamics simulation results demonstrate that CNT-CC-SRNC is in the disengaged state for the uncharged CNTs, whereas water confined in the two charged CNT walls can transmit the torque from the inner tube to the outer tube. Importantly, the proposed CNT-CC-SRNC can perform stepless speed-regulating function through changing the magnitude of the charge assigned on CNT atoms.
Investigation of energy transfer mechanisms between two adjacent phosphorescent emission layers
Authors: Diez Carola , Reusch Thilo C. G. , Seidel Stefan , Brütting Wolfgang
Published: June 2012

The investigation of energy transfer mechanisms between two adjacent phosphorescent emission layers comprising the green emitter molecule fac-tris(2-phenly-pyridin)iridium (Ir(ppy)3) and the red emitter molecule iridium(III)bis(2-methyldibenzo[f,h]quinoxaline(acetylacetonate) (Ir(MDQ)2(acac)) is presented. We show that the performance can be enhanced by a variation of the emission layer thickness and the emitter concentration. By inserting different interlayer materials between the emission units, we demonstrate that triplet excitons are formed on the Ir(ppy)3 and subsequently transferred to the Ir(MDQ)2(acac) molecules via the hole transporting host material N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-benzidine of the red emission layer. The variation of the interlayer thickness shows that the triplet diffusion length is several tens of nanometers. After optimization of the guest-host system an efficiency enhancement by 15% was achieved and the lifetime of the red-green emissive unit could be enhanced by 55%. Additionally, it is shown that this improved red-green unit can be combined with a fluorescent blue emitter in a state-of-the-art stacked white emissive organic light emitting diode.
Ion velocities in a micro-cathode arc thruster
Authors: Zhuang Taisen , Shashurin Alexey , Beilis Isak , Keidar Michael
Published: June 2012

Ion velocities in the plasma jet generated by the micro-cathode arc thruster are studied by means of time-of-flight method using enhanced ion detection system (EIDS). The EIDS triggers perturbations (spikes) on arc current waveform, and the larger current in the spike generates denser plasma bunches propagating along with the mainstream plasma. The EIDS utilizes double electrostatic probes rather than single probes. The average Ti ion velocity is measured to be around 2×104 m/s without a magnetic field. It was found that the application of a magnetic field does not change ion velocities in the interelectrode region while leads to ion acceleration in the free expanding plasma plume by a factor of about 2. Ion velocities of about 3.5×104 m/s were detected for the magnetic field of about 300 mT at distance of about 100–200 mm from the cathode. It is proposed that plasma is accelerated due to Lorentz force. The average thrust is calculated using the ion velocity measurements and the cathode mass consumption rate, and its increase with the magnetic field is demonstrated.