bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Relationship between Shock and Thermal Initiating Conditions for Various Reactive Powder Mixtures
Authors: Jetté François‐Xavier , Goroshin Samuel , Frost David L. , Higgins Andrew J. , Lee Julian J.
Published: June 2012

The critical conditions for initiation of reaction by shock loading in various compositions that produce little or no gas upon reaction were investigated. Shock recovery experiments using Mn+S were first carried out in two different apparatus geometries and for two different initial sample densities. In one geometry, the sample was subjected to a planar shock followed by interactions with the confining walls. In the other geometry, a curved shock free of wall interactions was delivered to the sample. The low‐density (55 % TMD) Mn+S was found to be significantly more sensitive to the curved shock than to the planar shock with wall interactions. For high‐density (90 % TMD) Mn+S samples however, shock sensitivity was the same in both apparatuses. Next, the reaction onset temperature and the critical initiating shock pressure were determined for a number of powder mixtures using DTA and shock recovery (in the geometry producing planar shocks with interactions with the confinement walls), respectively. For the majority of the mixtures tested, the minimum shock energy required to cause the entire sample mixture to react was found to be much less than the enthalpy of the sample at its reaction onset temperature, with no significant correlation between these two parameters. The process of arrested ball‐milling, which results in a reduction of the reaction onset temperature of a mixture, may lead to an increase in shock sensitivity. Additionally, thermal sensitivity in the particular mixtures considered was not increased when they were first shock‐compacted by sub‐critical shocks.
Oxidation of CdTe thin film in air coated with and without a CdCl2 layer
Authors: Bai Zhizhong , Wang Deliang
Published: June 2012

During the fabrication process of a CdS/CdTe solar cell, oxygen is often present or intentionally introduced in the CdTe growth and annealing atmospheres. In this study a comparative study was carried out on the oxidation of thin CdTe films during the annealing process in air when coated with and without a CdCl2 layer, respectively. It was found that the presence of a thin CdCl2 coating layer on the CdTe film surface enhanced the oxidation of the CdTe surface. Near the film surface, the film was composed of a low‐melting eutectic mixture of CdTe and oxides of CdTe and Te. The formation of the low‐melting mixture was assisted by the much lowered melting point of CdCl2, the presence of oxides, and the CdTe compound. This low‐melting layer enhanced the oxygen reaction with the CdTe film. The dominant oxide was CdTeO3. A CdTe solar cell with an efficiency of 9.9% was fabricated with a CdTe film subjected to an annealing in air at 400 °C with the presence of a CdCl2 coating layer.
Magnetic properties of Mg‐doped AlN zigzag nanowires
Authors: Hui Yeung Yu , Ye Jing , Lortz Rolf , Teng Kar Seng , Lau Shu Ping
Published: June 2012

Quasi‐aligned hexagonal Mg‐doped aluminum nitride zigzag nanowires (AlN:Mg ZNWs) were fabricated on sapphire substrates using chemical vapor deposition method. A saturated magnetic moment of ∼1 emu/cm3 was found in the AlN:Mg ZNWs when a magnetic field was applied parallel to the sample. The AlN:Mg ZNWs exhibited magnetic anisotropy. The magnetic moment was about 50% larger and the coercivity was about 20% smaller when the field was applied parallel to the sample as compared to the applied field perpendicular to the sample. The Curie temperature of the AlN:Mg ZNWs was above 400 K. The origin of the ferromagnetism in the AlN:Mg ZNWs could be attributed to the formation of Mg–N complex which leads to magnetic coupling as revealed by X‐ray photoelectron spectroscopy.
Electronic and magnetic properties of NiMn1−xHoxSb compounds
Authors: Grasin Robert , Rusu Calin , Laslo Ancuta , Dudric Roxana , Mican Sever , Neumann Manfred , Tetean Romulus
Published: June 2012

We study the effects of holmium doping in the half‐Heusler compound NiMnSb. Band structure calculations show that the half‐metallic properties are completely conserved if holmium atoms substitute the manganese ones. The antiparallel coupling of Ho and transition metal magnetic moments was found to be more favorable. The magnetization measurements are in agreement with the results of the structural and XPS analysis and confirm that the holmium atoms occupy lattice sites. There is a very good agreement between the experimental magnetic moments determined at 4.2 K and the calculated ones in the case of antiferromagnetic coupling between the Ho and transition metal magnetic moments.
Effect of strain on the excitonic polarization in graphene ribbons
Authors: Peng Feng , Wang Yatao
Published: June 2012

We study the coherent polarization of excitons in strained graphene ribbons using a bosonization scheme. Within linear elastic theory and a tight‐binding approach, we observe that strain can generate a marked influence on the coherent polarization of excitons and even effectively enhance polarization of excitons on certain conditions. We find that the polarization direction of the positive‐wavevector excitons is opposite to that of the negative‐wavevector excitons under high strain. We explain the micromechanism of generating these phenomena.
Preface: Phys. Status Solidi C 6/2012
Authors: Dappe Yannick , Jelínek Pavel , Cháb Vladimír
Published: June 2012

This issue of physica status solidi collects the Proceedings of the 13th International Conference on the Formation of Semiconductor Interfaces (ICFSI‐13) held in Prague between July 3 and 8, 2011. This series of conferences was organized by the Institute of Physics of the Academy of Sciences of the Czech Republic in cooperation with a group of scientists who started the organization of these meetings in Marseille (France) in 1985. The conferences bring together members of semiconductor physics communities to present and discuss advances of frontier trends in the broad area of semiconductor surface and interface formation. Generally, the scope of the series is concentrated on structure, electronic states, chemistry and dynamical phenomena and their role for future electronics. The meeting addressed the topics of application of theoretical approaches and simulations of interfaces and nanostructures.

Proof of the vitality of the conference series was given by the participation of scientists from 29 countries, where 4 out of them came from America, 6 from Asia and 2 from Africa. As much as 230 participants attended the event, and more than a hundred out of them were Ph.D. students or young scientists.

The participants have presented 35 invited talks, 76 oral contributions and more than 190 posters. Invited talks highlighted basic research in physics and chemistry at interfaces, mostly between semiconductors and organic molecules. The quality and diversity of the remainder of contributions, both oral and posters, opened up the conference as a steering pell‐mell for future electronics developments. The conference included also one workshop aimed at illustrating the fast developing area of single molecule application for molecular electronics.

We thank the International Steering and Program Committees for their wise suggestions on speakers and topics. We also warmly thank the local committee that had helped us tremendously. Finally, we would like to thank all sponsors of the ICFSI‐13 conference.

The next conference of this series will be held in Korea, 2013, chaired by of Prof. Han Woong Yeom.
Formulas Used by Tibetan Doctors at Men‐Tsee‐Khang in India for the Treatment of Neuropsychiatric Disorders and Their Correlation with Pharmacological Data
Authors: Antonio Raquel Luna , Kozasa Elisa H. , Galduróz José Carlos F. , Dawa  , Dorjee Yeshi , Kalsang Tsultrim , Norbu Tsering , Tenzin Tashi , Rodrigues Eliana
Published: June 2012

The aim of the present study was to identify formulas used at Men‐Tsee‐Khang (Tibetan Medical and Astrological Institute), India, for the treatment of neuropsychiatric disorders and to compare the Tibetan usage of particular ingredients with pharmacological data from the scientific database. Using ethnographic methods, five doctors were selected and interviewed. A correlation was observed between central nervous system disorders and rLung, one of the three humors in Tibetan medicine, which imbalance is the source of mental disorders, and ten multi‐ingredient formulas used to treat the imbalance of this particular humor were identified. These formulas utilize 61 ingredients; among them were 48 plant species. Each formula treats several symptoms related to rLung imbalance, so the plants may have therapeutic uses distinct from those of the formulas in which they are included. Myristica fragrans, nutmeg, is contained in 100% of the formulas, and its seeds exhibit stimulant and depressant actions affecting the central nervous system. Preclinical and clinical data from the scientific literature indicate that all of the formulas include ingredients with neuropsychiatric action and corroborate the therapeutic use of 75.6% of the plants. These findings indicate a level of congruence between the therapeutic uses of particular plant species in Tibetan and Western medicines. Copyright © 2012 John Wiley & Sons, Ltd.
Absorption and emission properties of various substituted cinnamic acids and cinnamates, based on TDDFT investigation
Authors: Promkatkaew Malinee , Suramitr Songwut , Karpkird Thitinun , Ehara Masahiro , Hannongbua Supa
Published: June 2012

Absorption and emission properties of the hydroxy‐, nitro‐, and fluoro‐group substituted at the ortho‐, meta‐, and para‐positions of cinnamic acids (1A–9A) and cinnamates (1E–9E) were investigated using the density functional theory (DFT) and time‐dependent DFT (TDDFT) calculations. The ground (S0)‐ and excited (S1)‐state geometries were obtained at the B3LYP/6‐31G(d) and TD‐B3LYP/6‐31G(d) methods, respectively. On the basis of the optimized structures of the S0‐ and S1‐states, the TDDFT calculations with B3LYP and CAM‐B3LYP functionals were performed to compute the absorption and emission energies of the various substituted cinnamic acids and cinnamates. The solvent effect was examined by the polarizable continuum model in methanol solution. As result, all compounds had the local minimum at the planar structure conformation due to π‐conjugation. The characteristics of the absorption spectra for cinnamic acid and cinnamate derivatives were satisfactorily reproduced by TDDFT method in gas phase and in methanol solution in both peak position and intensity. The emission from the local minimum in the planar structure was calculated for various substituted cinnamic acids and cinnamates. The results obtained by TDDFT investigation provide a useful insight into the detailed information on the optical and electronic properties of these compounds and a useful tool for designing and developing the superior UV absorber compounds. © 2012 Wiley Periodicals, Inc.
Electronic structure of a beryllium half‐sandwich complex, Be(η5‐C5H5)
Authors: Dolgounitcheva Olga , Zakrzewski V. G. , Ortiz J. V.
Published: June 2012

Ab initio electron propagator calculations on the electron affinities of the
$ {\rm Be(\eta ^5-C_5H_5)}^{+} $
complex cation and electron detachment energies of the corresponding anion have been performed at the optimized geometry of the ground state of the neutral species. These results, obtained with a basis set that includes many diffuse and polarization functions, provide the relative energies of doublet states of
$ {\rm Be(\eta ^5-C_5H_5)} $. In the former set of calculations, energy differences between the 2A1 ground‐state and various excited doublet states are associated with promotion of an unpaired electron from the 6a1 molecular orbital that consists chiefly of s functions on the Be nucleus to higher Be‐centered molecular orbitals that exhibit various patterns of interference between s, p, and d functions. Differences between electron detachment energies of the anion provide the energy separation between the radical's ground state and an excited state in which an electron is promoted from ligand‐centered π orbitals to 6a1. Dyson orbitals and pole strengths corresponding to correlated electron binding energies calculated with various diagonal self‐energy approximations confirm these qualitative pictures of the electronic structure of the lowest states of
$ {\rm Be(\eta ^5-C_5H_5)} $. © 2012 Wiley Periodicals, Inc.
A generalized sector‐bound approach to feedback stabilization of nonlinear control systems
Authors: Alvergue Luis , Gu Guoxiang , Acharya Sumanta
Published: June 2012

This paper proposes and develops a generalized sector‐bound approach to feedback stabilization of nonlinear control systems described by state–space models. This approach is inherited from the methodology of the sector‐bounded or passive nonlinearities and influenced by the concept of absolute and quadratic stability. It aims not only to regionally stabilize the nonlinear dynamics asymptotically but also to maximize the estimated region of quadratic attraction and to ensure nominal performance at each equilibrium. More importantly, it has a close connection to gain scheduling and switching control. A path of equilibria is programmed on the basis of the assumption of centered‐ ε‐cover, which leads to a sequence of linear controllers that regionally stabilize the desired equilibrium asymptotically. Simulation results are worked out to illustrate our proposed design method. Copyright © 2012 John Wiley & Sons, Ltd.
Remarks on the relationship between stability and internal stability of nonlinear systems
Authors: Wang Xu , Grip Håvard Fjær , Saberi Ali , Stoorvogel Anton A. , Saberi Ingmar
Published: June 2012

In this paper, we investigate the relationship between stability and internal stability of nonlinear systems. It is shown that under certain conditions, stability implies attractivity of the equilibrium and that local stability with finite gain implies local asymptotic stability of the origin. Copyright © 2012 John Wiley & Sons, Ltd.
Discrete‐time robust H∞control of a class of nonlinear uncertain systems
Authors: Shaiju A.J. , Petersen Ian R.
Published: June 2012

This paper presents an approach to discrete‐time robust H∞ control for a class of nonlinear uncertain systems on the basis of the use of Sum Quadratic Constraints. The approach involves controllers, which include copies of the system nonlinearities in the controller. The nonlinearities being considered are those that satisfy a certain global Lipschitz condition. The linear part of the controller is synthesized using linear robust H∞ control theory, and this leads to a nonlinear controller, which gives an upper bound on the attainable disturbance attenuation level. Copyright © 2012 John Wiley & Sons, Ltd.
Control over erasure channels: stochastic stability and performance of packetized unconstrained model predictive control
Authors: Reble Marcus , Quevedo Daniel E. , Allgöwer Frank
Published: June 2012

In this work, we consider the control of discrete‐time constrained nonlinear systems over unreliable packet‐based communication networks. The random packet dropouts are modeled by a two‐state Markov chain, and no acknowledgments of receipt are assumed. To weaken the impact of the packet dropouts, the controller transmits packets containing more than one future control input, and a suitable buffering is applied at the plant actuator side. Because the Markov chain model adopted does not ensure the number of consecutive packet dropouts to be bounded, deterministic stability cannot be guaranteed. Hence, we are interested in stochastic stability of the closed loop instead. We propose an unconstrained model predictive control scheme without additional terminal weighting term for the calculation of the control inputs. Two major advantages of this unconstrained model predictive control scheme can be emphasized. First, to guarantee stochastic stability, we do not require the knowledge of a global control Lyapunov function as terminal cost term but instead only a less restrictive controllability assumption. Second, guaranteed performance bounds on the expected infinite horizon cost of the closed loop can be obtained. Copyright © 2012 John Wiley & Sons, Ltd.
On decentralized group key management mechanism for vehicular ad hoc networks
Authors: Guo Ming‐Huang , Liaw Horng‐Twu , Chiu Meng‐Yu , Deng Der‐Jiunn
Published: June 2012

In a vehicular ad hoc network (VANET) environment, it is not easy to keep data secure and private. If the private data are stolen, the hacker might have the user identity and do some bad things. To provide secure transmitting, some data encryption mechanisms are necessary. In this paper, we proposed a group key management mechanism for data communication in VANETs. It is exploited on the basis of a decentralized architecture with the hierarchical key tree and cluster heads. The proposed mechanism not only provides a rekeying method in reducing the communication cost but also furnishes the forward security and backward security. Copyright © 2012 John Wiley & Sons, Ltd.
A survey on security issues in smart grids
Authors: Jokar Paria , Arianpoo Nasim , Leung Victor C. M.
Published: June 2012

A key feature of the smart grid is the introduction of two‐way data communications into the power grid. This brings many security challenges, because of the large‐scale, difficult‐to‐secure environment, complexity of smart grid systems, and resource limitations of the smart grid deployments. In this paper, we focus on security and privacy concerns in the context of the smart grid. Existing security mechanisms developed for traditional information technology systems can be used as a basis for designing security measures for the smart grid. However, new methods that meet the special requirements and characteristics of the smart grid are also required. In spite of the obstacles against developing detailed security solutions for the future smart grid, such as uncertainty of the architecture and lack of practical experiences with security attacks, some research has been performed in this area over the last few years. We survey the existing literature on different security aspects of the smart grid and provide directions for further research. Copyright © 2012 John Wiley & Sons, Ltd.
Are Clergy Serving Yoked Congregations More Vulnerable to Burnout? A Study among Clergy Serving in the Presbyterian Church (USA)
Authors: Francis Leslie J. , Robbins Mandy , Wulff Keith
Published: June 2012

Pressures generated by increasing secularization and decreasing vocations to ordained ministry are resulting across denominations in a growing number of clergy serving more than one congregation. This study assesses the hypothesis that clergy serving more than one congregation are more susceptible to burnout. Data were provided by a sample of 735 clergy serving in The Presbyterian Church (USA) who completed the Francis Burnout Inventory together with the abbreviated Eysenck Personality Questionnaire Revised. Among these clergy, 82% served one congregation, 13% served two congregations, and 5% served three or more congregations. After controlling for individual differences in age and personality, the data demonstrated that clergy serving yoked congregations experienced no statistically significant differences in susceptibility to burnout, either in terms of levels of emotional exhaustion or in terms of levels of satisfaction in ministry, compared with colleagues serving just one congregation. Copyright © 2012 John Wiley & Sons, Ltd.
Effects of Chewing Menthol Gum on the Alertness of Healthy Volunteers and Those with an Upper Respiratory Tract Illness
Authors: Smith Andrew P. , Boden Charlotte
Published: June 2012

Recent research has shown that chewing gum increases subjective alertness. Upper respiratory tract illnesses (URTIs) lead to reduced alertness, and it has been shown that stimulants such as caffeine can reverse this effect. It is now important to determine whether menthol chewing gum can produce a similar effect. Young adults with an URTI (N = 16) and a healthy control group (N = 12) rated their mood and symptoms on two occasions (the first when those with a URTI were ill and the second when both groups were healthy). During each session, volunteers provided a rating while chewing gum and when they were not chewing. Those with a URTI reported reduced alertness, which persisted into convalescence. Chewing gum was associated with greater alertness in both those with URTIs and the healthy group. Chewing gum reduced the severity of nasal symptoms in those with a cold. The effects of the URTI and menthol gum may reflect changes in trigeminal stimulation. Copyright © 2012 John Wiley & Sons, Ltd.
Extraordinary Physical Properties of Functionalized Graphene
Authors: Wei Weili , Qu Xiaogang
Published: June 2012

Graphene has attracted much attention in recent years due to its extraordinary electronic, optical, magnetic, thermal, and mechanical properties. Despite continuing theoretical and experimental success, the unique physical properties of graphene remain underused and underappreciated. The key challenge in harnessing of the unique properties of graphene is the difficulty of reliable manipulation of well‐dispersed graphene. Chemical and physical functionalization of graphene has become a focus of especial interest, because they can not only stabilize, but also induce new properties of graphene. This review summarizes the intriguing physical properties of chemically oxidized and noncovalently modified graphene, and graphene‐based nanocomposites with polymer matrices or nanoparticles. Along with introducing the physical properties of functionalized graphene, their potential applications in diverse research areas are discussed.
Local Equilibrium and Nodule Formation on Al‐TRIP‐Aided Steel Surfaces During Intercritical Annealing
Authors: Norden Martin , Blumenau Marc , Zimmermann Eva , Peters Klaus‐Josef
Published: June 2012

Several advanced high strength steels were intercritically annealed at a dew point of −5°C. Afterwards, surface morphology was investigated by scanning and transmission electron microscopy (TEM). In Al alloyed TRIP‐aided steels, nodules of metallic Fe containing traces of Mn could be proven by TEM analysis. To clarify the mechanism of origin, several further annealing trails were done and finally a new component of the occurring heterogeneous gas/metal reaction during intercritical annealing was postulated. It is concluded that neither the diffusion mechanism of the alloying elements nor the stress gradient between stress‐free surface region of the internal oxidation front nor the oxygen partial pressure dominates alone the selective oxidation process. It is suggested that the reactivity of the considered surface, its local surface chemistry and the local thermodynamic equilibrium should be taken into account in greater detail. Preferred dissociation points of absorbed water vapor could lead to a local increased oxygen partial pressure. With this, a nanoscaled oxidation/reduction process could be initiated.
Optimization of Two‐Strand Industrial Tundish Work with Use of Turbulence Inhibitors: Physical and Numerical Modeling
Authors: Merder Tomasz , Pieprzyca Jacek
Published: June 2012

The paper shows the results of the research obtained by physical and mathematical modeling of steel flow and mixing in the tundish. Two‐strand continuous casting tundish was under consideration. It has been working in one of polish steel plants. The change of concast slab assortment was caused by the changeable market terms. So, the tundish with the new system of steel flow controller was needed. Up to now baffles with the notch have played this role. Their placement cause the excessive consumption of the lining of the tundish front line. As a consequence the turbulence inhibitor (TI) was applied. Four different types of this inhibitor were designed. As a result of the experimental measurements and numerical simulations, the RTD curves of F‐type were obtained. Basing on these curves time constants for examined types were determined. Additionally, the research results were complemented by the E‐type curves. The percentage participations of dead volume flow, dispersed plug flow, and well‐mixed volume flow were calculated. The research gives possibility to estimate the designed TIs and their influence on the tundish work.
Bekenstein entropy bound for weakly-coupled field theories on a 3-sphere
Authors: Myers Joyce C.
Published: June 2012

Abstract

We calculate the high temperature partition functions for SU(N

c
) or U(N

c
) gauge theories in the deconfined phase on S
1 × S
3, with scalars, vectors, and/or fermions in an arbitrary representation, at zero ’t Hooft coupling and large N
c, using analytical methods. We compare these with numerical results which are also valid in the low temperature limit and show that the Bekenstein entropy bound resulting from the partition functions for theories with any amount of massless scalar, fermionic, and/or vector matter is always satisfied when the zero-point contribution is included, while the theory is sufficiently far from a phase transition. We further consider the effect of adding massive scalar or fermionic matter and show that the Bekenstein bound is satisfied when the Casimir energy is regularized under the constraint that it vanishes in the large mass limit. These calculations can be generalized straightforwardly for the case of a different number of spatial dimensions.
Spondylolysis is frequently missed by MRI in adolescents with back pain
Authors: Yamaguchi Kent T. , Skaggs David L. , Acevedo Daniel C. , Myung Karen S. , Choi Paul , Andras Lindsay
Published: June 2012

Purpose

Magnetic resonance imaging (MRI) is often used in the evaluation of lower back pain in adolescents. The purpose of our study is to report on the frequency of MRI missing spondylolysis in adolescents with back pain in a pediatric orthopaedic practice.

Methods

A retrospective review of all patients with a diagnosis of spondylolysis who presented from January 2000 to March 2010 was performed. All patients were evaluated at a single institution by the senior author. Inclusion criteria were patients with spondylolysis confirmed on computed tomography (CT) or plain film that also received an MRI.

Results

Eleven patients with spondylolysis had an MRI performed. The mean age of the study patients was 14.2 years (range 10–17). The diagnosis of spondylolysis was missed in the MRI radiology reading in 7 out of 11 (64 %) studies.

Conclusions

MRI missed a spondylolysis in over half of the adolescents in this consecutive series. In patients with a history or physical findings suggestive of spondylolysis, such as localized pain of the lumbar spine with back extension, further radiographic evaluation should be considered, even if an MRI is negative.

Level of evidence

III, retrospective review.
Evolution and Religion: Attitudes of Scottish Bioscience Students to the Teaching of Evolutionary Biology
Authors: Southcott Ronan , Downie J. Roger
Published: June 2012

In a questionnaire-based survey, the proportion of Glasgow University first year biology students who rejected evolution in 2009–2011 was about 7%, similar to the previously reported average figure for 1987–1999. However, by final year, evolution rejection was absent in students who studied evolution beyond first year and 4% among those who did not. Evolution rejection was closely related to accepting a religion-based alternative, whereas acceptance was related to finding the evidence convincing. Although many religious students accepted evolution, 50% of Islamic students were rejecters, compared to 25% of Christians. A question testing acceptance of several scientific propositions showed no evidence that evolution rejecters were generally more skeptical of science than accepters. Rejecters were overall less secure than accepters in their identification of the correct definition for terms related to evolution and creationism, but, surprisingly, more than 10% of final year students chose a Lamarckian definition for Darwinian evolution. Accepters and rejecters responded equally poorly to a question on Darwin’s history, but level 4 was much better. A breakdown of evolution into three components (human origins, macroevolution, and microevolution) found that some evolution rejecters accepted some components, with microevolution having the highest acceptance and human origins the lowest. These findings are discussed in terms of strategies for evolution education and the phenomenon of evolution rejection worldwide.
Cyclic AMP‐dependent protein kinase regulates 9G8‐mediated alternative splicing of tau exon 10
Authors: Gu Jianlan , Shi Jianhua , Wu Shiliang , Jin Nana , Qian Wei , Zhou Jianhua , Iqbal Inge-Grundke , Iqbal Khalid , Gong Cheng-Xin , Liu Fei
Published: June 2012

9G8
physically interacts with
PKA catalytic subunit
by coimmunoprecipitation (View interaction)
Down‐regulated miR‐625 suppresses invasion and metastasis of gastric cancer by targeting ILK
Authors: Wang Ming , Li Chenglong , Nie Hui , Lv Xin , Qu Ying , Yu Beiqin , Su Liping , Li Jianfang , Chen Xuehua , Ju Jingfang , Yu Yingyan , Yan Min , Gu Qinlong , Zhu Zhenggang , Liu Bingya
Published: June 2012

Accumulating evidence has shown that microRNAs are involved in multiple processes in cancer development and progression. Here, we report that expression of miR‐625 is significantly down‐regulated and negatively correlated with lymph node metastasis in gastric cancer. miR‐625 significantly inhibits invasion and metastasis of gastric cancer cells both in vitro and in vivo. Moreover, we identify that ILK is a direct target gene for miR‐625 and knockdown of ILK has a phenocopy of overexpression of miR‐625. Taken together, our findings suggest that miR‐625 plays an important role in the mechanism of tumor metastasis.
Inhibitory effect of SPE‐39 due to tyrosine phosphorylation and ubiquitination on the function of Vps33B in the EGF‐stimulated cells
Authors: Ishii Ayumi , Kamimori Kanae , Hiyoshi Mineyoshi , Kido Hiroshi , Ohta Takeshi , Konishi Hiroaki
Published: June 2012

Vps33B
and
SPE‐39
colocalize by fluorescence microscopy (View interaction)
Lipoma preferred partner is a mechanosensitive protein regulated by nitric oxide in the heart
Authors: Hooper Charlotte L. , Dash Philip R. , Boateng Samuel Y.
Published: June 2012

Adaptor proteins play an important role in signaling pathways by providing a platform on which many other proteins can interact. Malfunction or mislocalization of these proteins may play a role in the development of disease. Lipoma preferred partner (LPP) is a nucleocytoplasmic shuttling adaptor protein. Previous work shows that LPP plays a role in the function of smooth muscle cells and in atherosclerosis. In this study we wanted to determine whether LPP has a role in the myocardium. LPP expression increased by 56% in hearts from pressure overload aortic‐banded rats (p< 0.05 n = 4), but not after myocardial infarction, suggesting hemodynamic load regulates its expression. In vitro, LPP expression was 87% higher in cardiac fibroblasts than myocytes (p < 0.05 n = 3). LPP expression was downregulated in the absence of the actin cytoskeleton but not when microtubules were disassembled. We mechanically stretched cardiac fibroblasts using the Flexcell 4000 for 48 h (1 Hz, 5% maximum strain), which decreased total LPP total expression and membrane localization in subcellular fractions (p < 0.05, n = 5). However, L‐NAME, an inhibitor of nitric oxide synthase (NOS), significantly upregulated LPP expression. These findings suggest that LPP is regulated by a complex interplay between NO and mechanical cues and may play a role in heart failure induced by increased hemodynamic load.
A Victorian extinction: Alfred Newton and the evolution of animal protection
Authors: COWLES HENRY M.
Published: June 2012

The modern concept of extinction emerged in the Victorian period, though its chief proponent is seldom remembered today. Alfred Newton, for four decades the professor of zoology and comparative anatomy at Cambridge, was an expert on rare and extinct birds as well as on what he called ‘the exterminating process'. Combining traditional comparative morphology with Darwinian natural selection, Newton developed a particular sense of extinction that helped to shape contemporary, and subsequent, animal protection. Because he understood extinction as a process to be studied scientifically, and because he made that, rather than animal cruelty, the focus of animal protection, Newton provides an important window onto the relationship between science and sentiment in this period. Newton's efforts to bring the two into line around the issue of human-caused extinction reveal an important moment in which the boundaries between science and sentiment, and between those who did and those who did not have the authority to speak for nature, were up for grabs.
Validation of Default Probabilities
Authors: Blöchlinger Andreas
Published: June 2012

Well-performing default predictions show good discrimination and calibration. Discrimination is the ability to separate defaulters from nondefaulters. Calibration is the ability to make unbiased forecasts. I derive novel discrimination and calibration statistics to verify forecasts expressed in terms of probability under dependent observations. The test statistics’ asymptotic distributions can be derived in analytic form. Not accounting for cross correlation can result in the rejection of actually well-performing predictions, as shown in an empirical application. I demonstrate that forecasting errors must be serially uncorrelated. As a consequence, my multiperiod tests are statistically consistent.
Phytoplankton blooms detected by SeaWiFS along the central and southern California coast
Authors: Nezlin Nikolay P. , Sutula Martha A. , Stumpf Richard P. , Sengupta Ashmita
Published: June 2012

The effect of upwelling events, storm water discharge, and local circulation on phytoplankton blooms in the central California and Southern California Bight (SCB) coastal zones was analyzed using 10+ years (1997–2007) of remotely sensed surface chlorophyll concentration (CHL, derived from SeaWiFS ocean color), sea surface temperature, and modeled freshwater discharge. Analysis of variability and factors associated with phytoplankton blooms was conducted using the offshore extension of zones of CHL > 5 mg m−3; this method excludes terrestrial interference that complicates the use of ocean color to investigate phytoplankton blooms in coastal waters. In the SCB, blooms were most frequent in spring and associated with the spring transition to an upwelling regime. Along the Central Coast, blooms persisted from spring to autumn during seasonal intensification of upwelling. Offshore CHL extensions showed a significant positive trend during 1997–2007, with maxima in 2000–2001 and 2005–2006 that coincided with higher than normal frequency of upwelling events. Upwelling was found to be a major factor driving phytoplankton blooms, although the standard upwelling index derived from large‐scale atmospheric circulation was decoupled from the frequencies of both upwelling events and phytoplankton blooms. Areas of longer residence time associated with natural boundaries between coastal ocean regions had more extensive and persistent blooms. The influence of storm water discharge on offshore CHL extension appeared to be limited to areas in close proximity to major river mouths. These “hot spots” were also co‐located with ocean outfalls of Publicly Owned Treatment Works (POTW) discharge and, in some cases, longer residence time of coastal waters.
Human induced turbidity changes in Poyang Lake between 2000 and 2010: Observations from MODIS
Authors: Feng Lian , Hu Chuanmin , Chen Xiaoling , Tian Liqiao , Chen Liqiong
Published: June 2012

A robust retrieval algorithm to estimate concentrations of total suspended sediments (TSS) in Poyang Lake (the largest freshwater lake in China) was developed using Moderate Resolution Imaging Spectroradiometer (MODIS) medium‐resolution (250 m) data from 2000 to 2010 and in situ data collected during two cruise surveys. The algorithm was based on atmospherically corrected surface reflectance at 645 nm, with 1240 nm data serving as a reference for aerosols and a nearest‐neighbor method was used to avoid land adjacency effect. The algorithm showed an uncertainty of 30–40% for TSS ranging between 3 and 200 mg L−1. Long‐term TSS distribution maps derived from MODIS data and the customized TSS algorithm showed significant variations in both space and time, with low TSS (<10 mg L−1) in wet seasons and much higher TSS (>15–20 mg L−1) in dry seasons for the south lake, and generally higher TSS in the north lake. The TSS difference between the north and the south increased significantly after 2002, with mean TSS often reaching >40 mg L−1in the north. While the TSS seasonality was attributed to the seasonal changes of the lake's circulation, the inter‐annual variations were primarily driven by sand dredging activities, regulated by management policies. The case study here provides baseline water quality information for future restoration efforts in Poyang Lake, and more generally, an approach to assess water quality changes in similar water bodies, which have resulted from either climate variability or human activities.
River‐floodplain exchange and its effects on the fluvial oxygen regime in a large tropical river system (Kafue Flats, Zambia)
Authors: Zurbrügg Roland , Wamulume Jason , Kamanga Romas , Wehrli Bernhard , Senn David B.
Published: June 2012

Hydrological exchange between a river and its floodplain plays a critical role in maintaining key ecosystem services like habitat formation, nutrient transformation, and flood attenuation. We studied the spatial and temporal patterns of river‐floodplain exchange in the Kafue Flats, a 6500‐km2, dam‐impacted floodplain ecosystem in Zambia. In addition, we characterized the effects of floodplain runoff on river biogeochemistry and assessed dam‐related changes in the hydrological regime. The basic flood pulse concept poorly describes conditions in the Kafue Flats. Instead, high resolution measurements of discharge and tracers (specific conductivity,δ18O‐H2O) along 410 km of river revealed substantial spatial variations in both the magnitude and direction of river‐floodplain exchange. During peak discharge, a river channel constriction, 230 km into the floodplain, diverted as much as 80% of the river's ∼700 m3 s−1discharge into the floodplain. As a net result, >80% of the water exiting the Kafue Flats via the river, either passed through the floodplain or originated from precipitation on the floodplain. This floodplain‐derived water had a strong impact on river water quality, resulting in a seasonally recurring sharp decline in dissolved oxygen levels to <50μM that persisted for 150 km downstream. A comparison with historical flow data showed that concurrent bank overflow and floodplain inflows were a sustained pattern during the wet season. However, lateral exchange over an annual cycle has been reduced by as much as 50% due to dam operation.
Lithospheric‐folding‐based understanding on the origin of the back‐arc basaltic magmatism beneath Jeju volcanic island
Authors: Shin Young Hong , Choi Kwang Sun , Koh Jeong‐Seon , Yun Sung‐Hyo , Nakamura Eizo , Na Sung‐Ho
Published: June 2012

Compression near collisional plate boundaries causes lithospheric folding which results in the decrease of the pressure beneath the ridge of the fold while the pressure beneath the trough increases. The decompression beneath the lithosphere is likely to bring on basaltic magmatism along and below the ridge. We investigate the subsurface structure beneath Jeju (Cheju) volcanic island and its vicinity, and propose an alternative hypothesis that the basaltic magma beneath the island could be caused by (episodic) lithospheric folding. Unlike the prevailing hypothesis of the intraplate basaltic magmatism that requires extending lithosphere, our hypothesis can explain how the basaltic magma could be generated at the back‐arc regions without the extension.
Investigating step‐pool sequence stability
Authors: Waters Kevin A. , Curran Joanna Crowe
Published: June 2012

Step‐pool units, common features in steep, narrow streams, are highly dynamic systems that adjust during high flows and active sediment transport conditions. Consecutive step pools in a reach form a step‐pool sequence, and though these features are prevalent in nature, quantifying the stability of such systems is challenging. This study focuses on the statistical relationships between 445 stable sequences of three or more steps and nine geometric and resistance‐based parameters. Step sequence stability is parameterized through a sequence stability parameter, a metric of how long a given step‐pool sequence exists relative to the total run time. Despite variability in the strength of the statistical relationships, the results allow identification of dominant trends between sequence stability and both roughness and geometric parameters. The sediment concentration ratio provides a means for comparing the relative strength of these statistical relationships. As sediment concentration ratios increase, the relations between flow resistance parameters and step stability change from dominantly inverse to dominantly direct. Thus, at higher sediment concentration ratios, sequence stability is more likely to increase with flow resistance, but the reverse is more likely at low sediment concentration ratios. A connection exists between bed morphology, flow resistance, and stability. For the majority of stable step sequences, resistance parameters increase over time, indicating some sequences adjust their geometry to increase stability during flood events. The influence of sediment concentration over the stability‐geometric and stability‐resistance parameter relationships may enable the use of the sediment concentration ratio as a predictor of step sequence stability during a flow event.
High impact mass drops from helicopter: A new active seismic source method applied in an active volcanic setting
Authors: Jolly A. D. , Chardot L. , Neuberg J. , Fournier N. , Scott B. J. , Sherburn S.
Published: June 2012

We obtain estimates of the seismic velocity and attenuation for White Island volcano by use of high‐impact sand‐bag drops from helicopter. Three drops were attempted, two at either end of a 6‐station linear array within the crater floor, and the third in the volcano's crater lake. The bags were dropped from ∼310–380 m height and contained ∼700 kg of sand. The impact velocity was estimated at ∼60–70 m/s yielding a kinetic energy of about 106 Nm, giving P‐wave onsets to a distance of ∼1 km. We obtained a seismic velocity estimate ofVp = 1.2 km/s for the unconsolidated crater floor and Vp = 2.2 km/s for rays traversing through consolidated rock outside the crater. Attenuation was very strong (Q< 10) for both consolidated and unconsolidated parts of the volcano. This trial shows that low cost helicopter mass drops can be successfully applied to safely determine sub‐surface properties at hazardous volcanoes.
Magnetic latitude and local time distributions of ionospheric currents during a geomagnetic storm
Authors: Tsuji Yuji , Shinbori Atsuki , Kikuchi Takashi , Nagatsuma Tsutomu
Published: June 2012

In order to clarify the global distribution of ionospheric currents during a geomagnetic storm, we analyzed ground magnetic disturbances from high latitudes to the magnetic equator for the storm on September 7–8, 2002, with the minimum SYM‐H value of –168 nT. In this analysis, we investigated magnetic field deviations in the northward component from the SYM‐H, as functions of the dipole magnetic latitude (DMLAT) and the magnetic local time (MLT). During the main phase of the storm, the deviations at the low latitudes (10°−35° in DMLAT) were positive/negative in the dawn/dusk (0–9/11–24 h MLT) sector. On the other hand, the deviations at the dayside middle latitudes (35°–55° in DMLAT) were negative/positive in the morning/afternoon (6–12/13–15 h MLT) sector. The local time distribution at the low latitudes may represent the dawn‐dusk asymmetry of the storm time ring current, while that at the dayside middle latitudes coincides with the DP2 currents due to the convection electric field associated with the Region 1 field‐aligned currents (R1 FACs). All over the nightside middle latitude, the deviations were positive. This implies the direct effect of the R1 FACs through the Biot‐Savart's law. At the geomagnetic equator, the eastward and westward electrojets were intensified on the day and nightside, respectively, being caused by the penetrated dawn‐to‐dusk convection electric field. We found that the MLT distribution of the magnetic deviations during the recovery phase was in opposite sense to that during the main phase at the dayside middle latitudes. The reversed magnetic disturbances must be due to the overshielding electric field associated with the Region 2 field‐aligned currents (R2 FACs). Similarly, the deviations at the dayside and nightside equator were reversed, indicating penetration of the dusk‐to‐dawn overshielding electric field into the equatorial ionosphere. Based on the above results, we propose a current system including the ionospheric currents at middle latitudes caused by the R1/R2 FACs, equatorial EEJ/CEJ, and asymmetric ring current, during the main/recovery phase of the geomagnetic storm.
Ice‐volcano interactions during the 2010 Eyjafjallajökull eruption, as revealed by airborne imaging radar
Authors: Magnússon E. , Gudmundsson M. T. , Roberts M. J. , Sigurðsson G. , Höskuldsson F. , Oddsson B.
Published: June 2012

During the eruption of the ice‐covered Eyjafjallajökull volcano, a series of images from an airborne Synthetic Aperture Radar (SAR) were obtained by the Icelandic Coast Guard. Cloud obscured the summit from view during the first three days of the eruption, making the weather‐independent SAR a valuable monitoring resource. Radar images revealed the development of ice cauldrons in a 200 m thick ice cover within the summit caldera, as well as the formation of cauldrons to the immediate south of the caldera. Additionally, radar images were used to document the subglacial and supraglacial passage of floodwater to the north and south of the eruption site. The eruption breached the ice surface about four hours after its onset at about 01:30 UTC on 14 April 2010. The first SAR images, obtained between 08:55 and 10:42 UTC, show signs of limited supraglacial drainage from the eruption site. Floodwater began to drain from the ice cap almost 5.5 h after the beginning of the eruption, implying storage of meltwater at the eruption site due to initially constricted subglacial drainage from the caldera. Heat transfer rates from magma to ice during early stages of cauldron formation were about 1 MW m−2 in the radial direction and about 4 MW m−2 vertically. Meltwater release was characterized by accumulation and drainage with most of the volcanic material in the ice cauldrons being drained in hyperconcentrated floods. After the third day of the eruption, meltwater generation at the eruption site diminished due to an insulating lag of tephra.