bluuebunny/crossref_metadata_2025 huggingface dataset:
Hazards of unplanned power outages: Implementing appropriate safeguards
Authors: Ogle Russell A. , Morrison Delmar “Trey”
Published: March 2011

Accident root cause investigations often identify unplanned power outages as the cause of a catastrophic accident. Unplanned power outages can be an initiating event that leads to an emergency shutdown of a process unit. If the emergency shutdown is managed incorrectly, it can result in an uncontrolled release of hazardous chemicals.

To prevent a catastrophic accident, it is necessary to employ one or more safeguards to interrupt the chain of accident events. A process hazards analysis is the most effective tool for identifying these safeguards and evaluating their effectiveness prior to an incident. Examples of such safeguards are emergency shutdown procedures with operator training, emergency shutdown systems (including safety instrumented systems), and backup power supplies.

This article explores the ways in which hazard analysis and emergency planning can be utilized to ensure a safe transition to a secondary power source during an interruption of primary power. A case study of an accidental release of hydrochloric acid vapor is presented in which a safeguard failed to function during a power outage. An interesting feature of this incident was the excessive testing of the emergency power system that led to its premature and undetected failure. Thus, when commanded to operate during a power outage, the backup system failed. We illustrate how a layer of protection analysis, coupled with the development of best practices from industrial safety standards, would have suggested a better inspection and test protocol for the emergency power system. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011
The Buncefield explosion and fire–lessons learned
Authors: Mannan M. Sam
Published: March 2011

In December 2005, a succession of events triggered by the lack of redundant level control measures led to the release of large quantities of gasoline from a bulk storage facility in Buncefield near the Heathrow airport in United Kingdom. This article provides an analysis of the reasons behind the extent of the flammable vapor cloud that may have accumulated and the mechanism by which the overpressure was generated. This article also summarizes some of the past incidents involving open‐air vapor cloud explosions and the apparent similarities and parallels with the Buncefield incident.

The mechanism of the gasoline release and drop from height leads to vapor release and by the time the release hits the ground, most of the vapor is formed. The turbulence of the release itself created turbulence that caused air entrainment. After ignition, the well mixed fuel‐air vapor cloud attained higher flame speeds caused by the congestion and turbulence thus further exacerbating the intensity of the explosion. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011
Migration Transitions Revisited: Their Continued Relevance for The Development of Migration Theory
Authors: Skeldon Ronald
Published: March 2011

This paper is a reflection on the idea of transitions as explanatory frameworks for the study of population migration. Global transitions in fertility, mortality, and urbanisation are examined as background to the idea of a migration transition and its variants. The strengths and weaknesses of a transition approach to migration are outlined, focusing on the diffusion of a demographic process across space and through time. The concepts of ‘mobility’ and ‘migration’ transitions are assessed with the benefit of hindsight. In order to enhance the explanatory power of such transitions, I argue that they need to be linked with other economic, social, and political processes that are also diffusing in space and time. Agrarian, health, and gender transitions are briefly considered in this context, as is the whole question of migration and development. While no single pathway through any migration or developmental transition exists, it nevertheless needs to be accepted that a retreat to total relativism is counterproductive. The paper concludes by arguing that a transitional framework, which allows migration systems to be linked to wider socio‐economic change, provides a fertile environment in which to generate future theories of migration. Copyright © 2011 John Wiley & Sons, Ltd.
Nanoscale piezoresponse, acoustic and thermal microscopy of electronic ceramics
Authors: Leng Xue , Zeng Huarong , Liu Liming , Zhao Kunyu , Zeng Jiangtao , Li Guorong , Yin Qingrui
Published: March 2011

Piezoresponse force microscopy (PFM), scanning probe acoustic microscopy (SPAM) and scanning thermal microscopy (SThM) for visualising ferroelectric microstructure were successfully developed based on a commercial atomic force microscope, and their basic principle and applications to electronic ceramics were described as well. PFM, SPAM and SThM provide powerful tools for local electromechnical, elastic and thermal property of electronic ceramics.

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Advances in ab initio thermodynamic studies on metal/oxide interfaces
Authors: Li Hongtao , Zhang Wenqing , Smith John R.
Published: March 2011

We provide a brief overview of the advances in ab initio thermodynamic studies on metal/oxide interfaces in this paper. Firstly, the development in interface modeling is briefly outlined. Secondly, the fundamentals of ab initio thermodynamic method are described. Thirdly, ab initio thermodynamic studies on several typical interfaces between alumina and metals including alloys are presented, especially for the interfaces between α‐Al2O3 and Nb, Ni, Cu, and β‐Ni1−xAlx alloy. Finally, through analyzing electronic structure, chemical bonding, and adhesion of the interfaces between α‐Al2O3 and a series of metals, including Al, Ni, Cu, Au, Ag, Rh, Ir, Pd, Pt, Nb, and β‐NiAl, a formally unified model is derived for evaluating the works of separation of the representative aluminum‐rich, oxygen‐rich, and stoichiometric metal/α‐Al2O3 interfaces. This model is also expected to be valid for studying other metal/oxide interfaces.
Numerical analysis of light elements transport in a unidirectional solidification furnace
Authors: Kakimoto Koichi , Gao Bing , Nakano Satoshi
Published: March 2011

Quantitative study of light elements such as carbon and oxygen in multi‐crystalline silicon for solar cells is required to grow crystals with high quality. The transport of both carbon and oxygen is one of the critical issues to increase efficiency of solar cells made of silicon materials. Concentrations of carbon and oxygen in a furnace affect each others, therefore it is important to control mass transfer of carbon and oxygen in a furnace. Numerical calculation with a chemical reaction between carbon and oxygen was carried out to study how both light impurities are incorporated into crystals through the melt and gas during solidification process. The effects of flow rate and pressure on the impurities were examined. An increase in the flow rate can reduce both carbon and oxygen impurities in the crystal, though the reduction of carbon is more obvious. An increase in gas pressure can also obviously reduce the oxygen impurity but has only a small effect on the carbon impurity (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal stability of (Ce0.72Cu0.28)90‐xAl10Fex (x = 0, 5 or 10) bulk metallic glasses
Authors: Qiao J. C. , Pelletier J. M.
Published: March 2011

Thermal stability of (Ce0.72Cu0.28)90‐xAl10Fex (x= 0, 5 or 10) bulk metallic glasses (BMGs) was analyzed by differential scanning calorimetry (DSC) and X‐ray diffraction (XRD). Temperatures corresponding to glass transition (Tg), onset of crystallization (Tx) and crystallization peak (Tp) shift to higher temperature by increasing the Fe content. Kissinger model allows calculating the effective activation energy Ea of the crystallization process. For the first crystalline peak, energies are 1.47 eV, 1.50 eV and 1.58 eV for x = 0, 5 and 10, respectively, implying that effective activation energy Eaof the crystallization process increases by increasing the Fe content. In the iron‐free alloy, a second crystalline peak is observed, with activation energy of 2.3 eV. Influence of microstructure modifications on elastic and viscoelastic properties was investigated by dynamic mechanical analysis (DMA). (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
SU‐8 protective layer in photo‐resist patterning on As2S3 film
Authors: Choi Duk‐Yong , Madden Steve , Bulla Douglas , Rode Andrei , Wang Rongping , Luther‐Davies Barry
Published: March 2011

Amorphous chalcogenide thin films, especially arsenic tri‐sulphide (As2S3) are emerging as an excellent platform for integrated non‐linear optic devices due to their high non‐linearity as well as low linear and nonlinear optical loss. Fabricating planar As2S3 waveguides, however, is not straightforward because As2S3 is dissolved in alkalis such as photo‐resist developer. In this study we present the application of thin SU‐8 film as a protective layer to prevent the attack of the developer on the As2S3 during photolithographic process. Despite excellent coating feature and simple process of SU‐8 as a protective layer, the delamination between SU‐8 and polymer cladding during chip cleaving hindered its application. We deposited thin Al2O3 on SU‐8 by atomic layer deposition and this intermediate layer could solve the problem. We measured the insertion losses of fabricated waveguides as a function of device lengths and widths. The propagation loss becomes significant in a narrow guide due to the enhanced surface scattering. It was clear that extra losses were engaged in long guides containing bending structures. SU‐8 layer and thin Al2O3 combination allowed reliable and repeatable fabrication process in that it did not induce any extra light scattering or absorption and prevented attack of the As2S3 film by the alkaline developer. Moreover, the device characterisation revealed that SU‐8 layer is superior to PMMA/BARC in terms of propagation loss of waveguide (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A unified configuration‐coordinate model of structural metastability in amorphous chalcogenide glasses
Authors: Balitska Valentina , Shpotyuk Oleh
Published: March 2011

The unified configuration‐coordinate model, describing externally‐induced structural transformations in amorphous chalcogenide semiconductors, was developed. Within this model, the existing structural units of glass‐forming matrix are supposed to be in one of three possible states: the ground (most thermodynamically equilibrium), excited (transient) and structurally‐modified (metastable) states, interconnected with a system of vertical (radiative or non‐radiative) and thermally‐activated over‐barrier tunnelling transitions. This model is used to describe kinetics of induced metastability in amorphous chalcogenides (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal properties and microstructural characterization of vanadium germanate glasses
Authors: Yılmaz Deniz , Tatar Demet , Cem Elbizim M. , Lütfi Öveçoğlu M.
Published: March 2011

Thermal and microstructural characterization investigations of (1‐x) GeO2 ‐ x V2O5 (x=0.10, 0.30, 0.42 and 0.60 in molar ratio) glasses were carried out using differential thermal analysis (DTA), X‐ray diffractometry (XRD) and scanning electron microscopy (SEM) techniques. Effects of heating rate and vanadium content on the glass transition, crystallization and melting temperature were investigated. XRD results have indicated that α‐GeO2, β‐GeO2, V2O5 crystal phases were formed when the samples were annealed above the crystallization peak temperature. SEM/EDS investigations were conducted for the microstructural characterization of α‐GeO2, β‐GeO2, V2O5 crystal phases. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Giant magnetoimpedance effect of ac‐dc Joule annealed electroplated NiFe/Cu composite wires
Authors: Ghanaatshoar M. , Azad N. , Banitaba M. H. , Shokri B.
Published: March 2011

In this article, we investigate the influence of ac‐dc Joule annealing of NiFe microtubes on their giant magnetoimpedance effect. NiFe magnetic layers were electroplated onto 100‐μm‐diameter copper wires and then submitted to dc or ac‐dc current annealing for 8 minutes. Both annealing and cooling down processes were performed in argon atmosphere.

Results show that the presence of ac part of Joule treatment leads to higher induced anisotropy and increases the MI ratio. It is conjectured that the ac component through wall movement and moment fluctuation increases the tendency of the magnetic domains to lie circumferentially. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of disorder induced by annealing and quench and by ball‐milling in B2 FeCo
Authors: Loureiro J. M. , Malaman B. , Costa B. F. O. , Le Caër G. , Khomchenko V. A. , Das S. , Amaral V. S.
Published: March 2011

Order‐disorder in FeCo are studied by X‐ray diffraction, Mössbauer spectroscopy and saturation magnetization measurements in applied fields up to 10 T. Order is promoted by annealing at 550 °C and the alloy is disordered either by high‐temperature annealing at 980 °C followed by a quench into cooled water or by ball‐ milling. A more disordered state is reached by ball‐milling in our dynamical conditions than the one reported to be attained by annealing and quench even at rather high rates. A saturation magnetization as high as 2.51 μB/at. is obtained. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preface – Symposium J: Phys. Status Solidi C 3/2011
Authors: Valenta Jan , Kovalev Dmitry , Gregorkiewicz Tom , Michel Jürgen
Published: March 2011

This special issue of physica status solidi features the papers presented at Symposium J of the 2010 Spring Meeting of the European Materials Research Society (E‐MRS) entitled Silicon based Nanophotonics, held in Strasbourg (France) on June 7–11, 2010. These Proceedings address several issues in silicon based nanophotonic materials and devices, from materials growth of nanosized structures to devices. The focus is on the use of silicon as a substrate material to utilize the infrastructure of the silicon microelectronics industry.

Over the last few years there has been a strong emphasis to develop photonic devices based on silicon, driven by the prospect of integration into the inexpensive silicon electronics platform. More recently, apparent limitations in heat dissipation and the interconnect bottleneck in microprocessors has fueled the research into monolithically integrated photonic devices to alleviate these limitations. A large number of Si compatible devices have been developed; however, the size of these devices often limits their usefulness for integration into microprocessors. Therefore, these Proceedings focus on the properties of nano scale photonic devices, with the expectations that it will stimulate the development of novel devices and functionalities.

This issues features 25 peer reviewed articles that were organized into 7 topics: (1) Nonlinear optical properties of Si nanocrystals; (2) Radiative and non‐radiative recombination in Si‐based materials; (3) Silicon nanowires and nanorods; (4) Er‐doped nanostructures; (5) Silicon‐germanium nanostructures; (6) Photonic structures: Microcavities, photonic crystals and waveguides; (7) Si nanostructures for light detection and sensing.

We would like to thank all authors for their contributions and the reviewers for their prompt response and comments that have improved the quality of the Proceedings and were instrumental in finalizing the Proceedings in a timely manner.

We would also like to thank the scientific advisory committee, Prof. Minoru Fujii, Prof. Yasuhiko Ishikawa, Prof. Wolfgang Jantsch, Prof. Jan Linnros, Dr. Michael Morse, Prof. Stefano Ossicini, Prof. Tony Peaker, Dr. Richard Rizk, Prof. Margit Zacharias, and Prof. Zhiping (James) Zhou for their significant contributions through all stages of the Symposium organization and Proceedings preparation (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Wide band gap and p‐type conductive Cu–Nb–O films
Authors: Yamazoe Seiji , Yanagimoto Shunsuke , Wada Takahiro
Published: March 2011

Cu–Nb–O films with a thickness of ca. 150 nm were prepared on borosilicate glass substrates using CuNbO3 ceramic target at substrate temperature of 500 °C by pulsed laser deposition. The X‐ray diffraction patterns showed that the Cu–Nb–O films were amorphous or an aggregation of fine crystals. The post‐annealed film at 300 °C in N2 gas showed 80% transmission in visible light (band gap = 2.6 eV) and high p‐type conductivity of 21 S cm–1. The Cu–Nb–O film with a thickness of 100 nm, fabricated from the target with a composition of Cu/Nb = 0.9, showed the highest p‐type conductivity of 116 S cm–1. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A note on dealing with missing standard errors in meta‐analyses of continuous outcome measures in WinBUGS
Authors: Stevens John W.
Published: March 2011

A meta‐analysis of a continuous outcome measure may involve missing standard errors. This is not a problem depending on assumptions made about the population standard deviation. Multiple imputation can be used to impute missing values while allowing for uncertainty in the imputation. Markov chain Monte Carlo simulation is a multiple imputation technique for generating posterior predictive distributions for missing data. We present an example of imputing missing variances using WinBUGS. The example highlights the importance of checking model assumptions, whether for missing or observed data. Copyright © 2011 John Wiley & Sons, Ltd.
Apoptosis of Human Cholangiocarcinoma Cell Lines induced by β‐Escin through Mitochondrial Caspase‐dependent Pathway
Authors: Shen Dong‐Yan , Kang Jin‐He , Song Wei , Zhang Wen‐Qing , Li Wen‐Gang , Zhao Yan , Chen Qing‐Xi
Published: March 2011

The study aimed to evaluate the effects of β‐escin on human cholangiocarcinoma cell lines (QBC939, Sk‐ChA‐1 and MZ‐ChA‐1) and to explore its mechanisms. Cell growth, cell cycle and apoptosis were investigated, respectively, by MTT assay, single PI and FITC/PI double‐staining flow cytometry, and fluorescence microscopy. The protein expression was determined by western blotting. The study revealed that β‐escin inhibited cholangiocarcinoma cell growth in a dose‐ and time‐dependent manner, and the cell cycle of QBC939 and Sk‐ChA‐1 cells was arrested in the G2/M phase, and MZ‐ChA‐1 cells in G1 phase. Apoptosis of the three cholangiocarcinoma cell lines induced by β‐escin was associated with the collapse of the mitochondrial membrane potential and the activation of caspase‐3. The apoptotic effect of β‐escin was suppressed by pancaspase inhibitor z‐VAD‐fmk. Molecular dissection revealed that the antiapoptotic protein bcl‐2 was down‐regulated after cholangiocarcinoma cell lines were treated with β‐escin, while the protein levels of bax and p53 were unchanged. Apoptosis was accompanied by an increase in reactive oxygen species (ROS). These results suggest that β‐escin induces apoptosis of cholangiocarcinoma cells through an intrinsic mitochondrial caspase‐dependent pathway, and the increase in the bax/bcl‐2 ratio and ROS may play important roles in β‐escin‐induced apoptosis of cholangiocarcinoma cells. Copyright © 2011 John Wiley & Sons, Ltd.
Ergosta‐7,22‐diene‐2β,3α,9α‐triol from the Fruit Bodies of Ganoderma lucidum Induces Apoptosis in Human Myelocytic HL‐60 Cells
Authors: Lee Mi Kyoung , Hung Tran Manh , Cuong To Dao , Na MinKyun , Kim Jin Cheol , Kim Eun‐Jung , Park Hee‐Sung , Choi Jae Sue , Lee IkSoo , Bae KiHwan , Hattori Masao , Min Byung Sun
Published: March 2011

Ganoderma lucidum is known as a medicinal mushroom used in traditional medicine. In our study, the cytotoxic activities of 17 compounds (1–17) isolated from the fruiting bodies of G. lucidum were investigated. Among them, ergosta‐7,22‐diene‐2β,3α,9α‐triol (EGDT) induced apoptosis in HL‐60 human premyelocytic leukemia cells. EGDT activated the apoptotic process, including DNA fragmentation and caspase‐3 activity. In immunoblotting analysis, treatment with EGDT resulted in the cleavage of procaspase‐3 and poly(ADP‐ribose) polymerase (PARP) into active forms. In the in vivo study, the administration (i.p.) of EGDT to Lewis lung carcinoma (LLC)‐inoculated mice evidenced a significant inhibition of tumor growth. These results indicate that EGDT was one of the apoptotic constituents of G. lucidum, and might be an antitumor agent. Copyright © 2011 John Wiley & Sons, Ltd.
Protective Effect of Dietary Tocotrienols against Infection and Inflammation‐induced Hyperlipidemia: AnIn VivoandIn SilicoStudy
Authors: Salman Khan M. , Akhtar Salman , Al‐Sagair Othman A. , Arif Jamal M.
Published: March 2011

Currently used hypolipidemic drugs, Fluvastatin and Atorvastatin, act via inhibiting the rate‐limiting enzyme 3‐hydroxy‐3‐methyl‐glutaryl‐coenzyme A (HMG‐CoA) reductase of the mevalonate pathway. The associated severe side‐effects of these statins led us to explore the therapeutic potentials of naturally occurring Tocomin (mixture of dietary α‐, β‐, γ‐ and δ‐tocotrienols). Tocomin (10 mg) was orally administered daily for 10 days before and 12 h after bacterial lipopolysaccharide (200 μg) or 24 h after zymosan (20 mg) or turpentine (0.5 mL) to Syrian hamsters. The data showed that Tocomin significantly reduced the levels of plasma and lipoprotein lipids, cholesterol, apoB, small dense (sd)‐LDL as well as LDL in the hyperlipidemia‐induced hamsters. Further, the mechanism of action of α‐, β‐, γ‐ and δ‐tocotrienols was validated by docking studies with HMG‐CoA reductase enzyme using the Molegro Virtual Docker. The inhibition of HMG‐CoA reductase predicted in terms of MolDockScore and interaction energy suggest the comparative potential in the descending order: Atorvastatin > Fluvastatin ~ δ > γ > β > α. The results favor the daily intake of naturally occurring tocotrienols as dietary supplement in the prevention and treatment of infection/inflammation induced dyslipidemia compared with the hypolipidemic drugs. Copyright © 2011 John Wiley & Sons, Ltd.
Up‐regulation of VEGF by MC3T3‐E1 Cells Treated with Curculigoside
Authors: Ma Chengjian , Zhang Junyu , Fu Jiehai , Cheng Linfang , Zhao Guangshu , Gu Yaping
Published: March 2011

Empirical evidence has shown that curculigoside, the main active compound of the traditionally used Chinese herb, Curculigo orchioides (Amaryllidaceae, rhizome), affects bone formation and fracture healing. However, the mechanistic details of these processes remain unclear. Therefore, the effects of curculigoside on immortalized, pre‐osteoblastic mouse MC3T3‐E1 cells was investigated. Following treatment with curculigoside, MC3T3‐E1 cells exhibited an increased rate of proliferation. Higher levels of vascular endothelial growth factor (VEGF), Fms‐like tyrosine kinase‐1 (Flt‐1) and bone morphogenetic protein‐2 (BMP‐2) were also detected in cell supernatants and cell lysates by ELISA and western blot analysis, respectively. Furthermore, the stimulatory effect of curculigoside was observed at relatively low doses (i.e. 10–100 μg/mL). In combination, these responses to treatment with curculigoside elucidate mechanistic details underlying the therapeutic effects of Curculigo orchioides on bone, and identifies these molecules as potential targets for the treatment of common metabolic bone diseases. Copyright © 2011 John Wiley & Sons, Ltd.
Antiplatelet Activity of Phellinus baummii Methanol Extract is Mediated by Cyclic AMP Elevation and Inhibition of Collagen‐activated Integrin‐αIIbβ3 and MAP Kinase
Authors: Kamruzzaman S. M. , Endale Mehari , Oh Won‐Jun , Park Seung‐Chun , Kim Tae‐Hwan , Lee In‐Kyoung , Cho Jae Youl , Park Hwa‐Jin , Kim Sang Keun , Yun Bong‐Sik , Rhee Man Hee
Published: March 2011

Phellinus baumii is a mushroom that has been used as folk medicine against various diseases and is reported to have antidiabetic, anticancer, antioxidant, antiinflammatory and antihypertensive activities. However, information on the effects of P. baumii extract in platelet function is limited. Therefore, the aim of this study was to examine the impact of a P. baumii methanol extract (PBME) on platelet activation and to investigate the mechanism behind its antiplatelet activity. PBME effects on agonist‐induced platelet aggregation, granule secretion, [Ca2+]i mobilization, αIIbβ3 activation, cyclic AMP release and mitogen‐activated protein kinase (MAPK) phosphorylations were studied using rat platelets. PBME dose‐dependently inhibited collagen, thrombin and ADP‐induced platelet aggregation with an IC50 of 51.0 ± 2.4, 54.0 ± 2.1 and 53.0 ± 4.3 μg/mL, respectively. Likewise, thrombin‐induced [Ca2+]i and collagen‐activated ATP secretions were suppressed in PBME treated platelets. Aggregation and ATP secretion were also markedly attenuated by PBME alone or in combination with PP2 (Src inhibitor) and U‐73122 (PLC inhibitor) in collagen‐stimulated platelets. Besides, PBME treatment elevated basal cyclic AMP levels and inhibited collagen‐induced integrin‐αIIbβ3 activation. Moreover, PBME attenuated extracellular‐signal‐regulated protein kinase 2 (ERK2) and c‐Jun N‐terminal kinase 1 (JNK1) phosphorylations. Further PD98059 (ERK inhibitor) and SP60025 (JNK inhibitor) reduced collagen‐induced platelet aggregation and ATP secretion. In conclusion, the observed PBME antiplatelet activity may be mediated by activation of cyclic AMP and inhibition of ERK2 and JNK1 phosphorylations. Finally, these data suggest that PBME may have therapeutic potential for the treatment of cardiovascular diseases that involve aberrant platelet function. Copyright © 2011 John Wiley & Sons, Ltd.
From legitimacy to impact: Moving the field forward by asking how entrepreneurship informs life
Authors: Lumpkin G. T.
Published: March 2011

Entrepreneurship as a field of research has grown significantly since the publication of Lumpkin and Dess (1996), an article that addressed what it means to be entrepreneurial. The field has gained legitimacy in part through research that asks how phenomena such as market conditions, institutional environments, and strategic behaviors inform the entrepreneurship domain. New progress can be made by asking how phenomena unique to the domain of entrepreneurship help researchers understand decisions, actions, and environments outside of the domain. Ideas for using entrepreneurial knowledge to explain more general phenomena are presented. Copyright © 2011 Strategic Management Society.
Dose‐finding design driven by efficacy in onco‐hematology phase I/II trials
Authors: Seegers V. , Chevret S. , Resche‐Rigon M.
Published: March 2011

We present an adaptive model‐based procedure for dose finding in phase I/II clinical trials when both efficacy and toxicity responses are available. In this setting, previous designs aimed at identifying the maximum tolerated dose as a surrogate for efficacy or the most successful dose, defined as the dose with the highest probability of efficacy without toxicity. Rather than using this definition of success, we propose considering all responses conditionally on the probability that dose‐limiting toxicity is under a pre‐specified threshold. The presented approach uses a joint model for the probability of an efficacy response and toxicity, and is evaluated through simulations. A retrospective application to a Phase I trial conducted in chronic lymphocytic leukemia is presented. Copyright © 2011 John Wiley & Sons, Ltd.
Control of Self‐Assembled 2D Nanostructures by Methylation of Guanine
Authors: Bald Ilko , Wang Yao‐guang , Dong Mingdong , Rosen Christian B. , Ravnsbæk Jens B. , Zhuang Gui‐lin , Gothelf Kurt V. , Wang Jian‐guo , Besenbacher Flemming
Published: March 2011

Methylation of DNA nucleobases is an important control mechanism in biology applied, for example, in the regulation of gene expression. The effect of methylation on the intermolecular interactions between guanine molecules is studied through an interplay between scanning tunneling microscopy (STM) and density functional theory with empirical dispersion correction (DFT‐D). The present STM and DFT‐D results show that methylation of guanine can have subtle effects on the hydrogen‐bond strength with a strong dependence on the position of methylation. It is demonstrated that the methylation of DNA nucleobases is a precise means to tune intermolecular interactions and consequently enables very specific recognition of DNA methylation by enzymes. This scheme is used to generate four different types of artificial 2D nanostructures from methylated guanine. For instance, a 2D guanine windmill motif that is stabilized by cooperative hydrogen bonding is revealed. It forms by self‐assembly on a graphite surface under ambient conditions at the liquid–solid interface when the hydrogen‐bonding donor at the N1 site of guanine is blocked by a methyl group.
A study of irreducibility in C programs
Authors: Stanier James , Watson Des
Published: March 2011

Compilers use a variety of techniques to optimize and transform loops. However, many of these optimizations do not work when the loop is irreducible. Node splitting techniques transform irreducible loops into reducible loops, but many real‐world compilers choose to leave them unoptimized. This article describes an empirical study of irreducibility in current versions of open‐source software, and then compares them with older versions. We also study machine‐generated C code from a number of software tools. We find that irreducibility is extremely rare, and is becoming less common with time. We conclude that leaving irreducible loops unoptimized is a perfectly feasible future‐proof option due to the rarity of its occurrence in non‐trivial software. Copyright © 2011 John Wiley & Sons, Ltd.
Toward reusable SLA monitoring capabilities
Authors: Parkin Simon E. , Morgan Graham
Published: March 2011

Within Internet‐based service environments, distributed monitoring mechanisms face challenges with respect to the diverse communication protocols, application languages, and monitoring requirements that exist. Creation of monitoring solutions on a per‐service basis becomes time‐consuming and misses opportunities to reuse existing logic. Ideally the deployment of monitoring solutions would be simple. Simplicity could be achieved by freeing monitoring solutions from domain dependencies, promoting the ability to use automatically generated monitoring code and support for the automated deployment of monitoring components. Work is presented here that progresses these ambitions by providing a generic, distributed monitoring and evaluation framework based on Metric Collector (MeCo) components. MeCo components form part of a unified monitoring framework which can interpret Service Level Agreements to automatically provide tailored service monitoring. Once deployed, these components can gather measurement data across a range of service technologies as used within E‐Commerce services, with minimal impact upon observed service environments. Copyright © 2011 John Wiley & Sons, Ltd.
On the Entropy of Social Systems: A Revision of the Concepts of Entropy and Energy in the Social Context
Authors: Mavrofides Thomas , Kameas Achilleas , Papageorgiou Dimitris , Los Antonios
Published: March 2011

The main problem that systems theory tries to solve is the problem of complexity. The notion of complexity is very often correlated to variables such as entropy and energy, organization and disorganization and others that eventually converge to the common ground of comprehensibility or incomprehensibility. In this paper, we try to shed light on the notions of entropy and energy as they should be conceived in the theoretical framework of social sciences. We analyse the different meanings of entropy, dealing with the social systems as if they were information management systems (following Niklas Luhmann), and we also present an initial approach, as to the meaning of energy for those systems, bringing Pierre Bourdieu's theory of symbolic capital into a Luhmannian context. Copyright © 2011 John Wiley & Sons, Ltd.
A new method for testing timed systems
Authors: Bonifácio Adilson Luiz , Moura Arnaldo Vieira
Published: March 2011

Devising formal techniques and methods that can automatically generate test suites for timed systems has remained a challenge. In this paper Timed Input/Output Automata (TIOA) are used as a formal specification model for timed systems. This work proposes and proves the correctness of a new and more general discretization method that can be used to obtain grid automata corresponding to specification TIOA, using almost any granularity of interest. Such flexibility to find a suitable granularity opens the possibility for a more compact construction of grid automata. It is also shown how test purposes can be used together with the specification TIOA in order to generate grid automata that capture the behavior of both the specification and the test purpose. From such grid automata one can algorithmically extract test suites that can be used to verify whether given implementations adhere to the specification and reflect the properties modeled using the test purposes. Copyright © 2011 John Wiley & Sons, Ltd.
Software reliability
Authors: Soyer Refik
Published: March 2011

In this article, we present an overview of the state of the art in software reliability. We present some of the traditional software reliability models as well as recent advances in modeling. In so doing, we discuss use of hidden Markov models, as well as nonparametric models including mixtures of Dirichlet processes. Furthermore, we review decision problems in software reliability such as testing strategies and optimal stopping rules. We discuss computational issues associated with use of the models, their statistical analyses and development of optimal strategies. WIREs Comp Stat 2011 3 269–281 DOI: 10.1002/wics.159

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Bayesian Methods and Theory

Statistical and Graphical Methods of Data Analysis > Reliability, Survivability, and Quality Control

Software for Computational Statistics > Software/Statistical Software

Data: Types and Structure > Time Series, Stochastic Processes, and Functional Data
Evolution of the Minimally Invasive Treatment of Esophageal Achalasia
Authors: Bello Brian , Herbella Fernando A. , Patti Marco G.
Published: March 2011

Thanks to the advent of laparoscopic techniques, the last decade and a half have witnessed a radical change in the treatment of esophageal achalasia. Because of the high success rate of the laparoscopic Heller myotomy, surgery has now become in many centers the first modality of treatment for achalasia. This shift in the treatment algorithm reflects the fact that laparoscopic Heller myotomy with partial fundoplication outperforms nonsurgical approaches, such as balloon dilatation and intrasphincteric botulinum toxin injection.
Laparoscopic Repair of Inguinal Hernias
Authors: Carter Jonathan , Duh Quan‐Yang
Published: March 2011

For patients with recurrent inguinal hernia, or bilateral inguinal hernia, or for women, laparoscopic repair offers significant advantages over open techniques with regard to recurrence risk, pain, and recovery. For unilateral first‐time hernias, either laparoscopic or open repair with mesh can offer excellent results. The major drawback of laparoscopy is that the technique requires a significant number of cases to master. For surgeons in group practice, it makes sense to have one surgeon in the group perform laparoscopic repairs so that experience can be concentrated. For others, the best technique remains the approach that the surgeon is most comfortable and experienced performing.
Effect of Water on the Ethanolysis of Waste Cooking Soybean Oil Using a Tin(II) Chloride Catalyst
Authors: da Silva Milene L. , Figueiredo Ana P. , Cardoso Abiney L. , Natalino Ricardo , da Silva Márcio J.
Published: March 2011

Biodiesel production from cheap lipid raw materials is economically welcome, but a high free fatty acids (FFA) content makes it incompatible with traditional alkaline catalysts. Although liquid mineral acids are alternatively used, serious drawbacks such as high corrosiveness and large effluent generation, as well as the impossibility of catalyst reuse compromises its application. Contrarily, solid acid catalysts appear to be an attractive option; however, the water present or generated during FFA esterification provokes the leaching and deactivation of these catalysts. Thus, in this work we have evaluated the use of tin chloride SnCl2, which is less corrosive, water tolerant, and a recyclable Lewis acid catalyst, on FFA ethanolysis using waste cooking oil samples (WCO). Additionally, the main kinetic parameters of the reactions were assessed. Compared to pTSA (p‐toluenesulfonic‐acid), a catalyst also evaluated, SnCl2 efficiently promoted FFA ethanolysis even in the presence of high amounts of water (ca. 0.1–5.0% w/w). Moreover, the homogeneous SnCl2 catalyst was easily recovered and reused successively, without loss of activity.
Understanding the Tectonic Behaviour of the Shillong Plateau, India using Remote Sensing Data
Authors: Duarah B. P. , Phukan Sarat
Published: March 2011

Shillong Plateau in India is tectonically and geologically interesting entity in the subducted front of Indian Plate below Burmese Plate to the southeast and Tibetan Plate to the north and associated with thrusts and shears along the plate boundaries. Horse-tail geometry in the foothills of the Arunachal Himalaya, east of Jia Bhareli river, associated with south-convex foothill ranges in the eastern Himalaya and exactly similar structural geometry in the eastern part of Shillong Plateau in Meghalaya seems to develop due to resistance received by the plateau in its eastward journey. Wide separation of Karbi Anglong Plateau and Shillong Plateau to the southeast as compared to northwestern part defines the shape of Kopili graben. Low seismic activity in southeastern part of Shillong Plateau might be related to stress released field generated by its clockwise rotation. Satellite derived images and digital elevation data from Landsat ETM+ and SRTM data shows that the central part of Shillong Plateau possesses young topography with strong structural fabrics along with relatively high topography aligning NE-SW following Kolkota-Pabna-Mymansingh High and if extended passes through western part of Arunachal Pradesh in eastern Himalayas. This alignment has been observed in Precambrian gneissic complex west of the Proterozoic intracratonic Shillong Basin. The epicentral plot for the period 1918 to 2009 shows their high concentration within the Shillong Plateau aligning along this trend. The active geodynamics of Shillong Plateau is reflected in its seismic activity pattern in relation with the structural fabrics, northward migration of the Brahmaputra in the north front of the Plateau and by shrinking pattern of Chandubi Lake in the Kulsi river catchment, a north-flowing tributary of the Brahmaputra in the north-central part of the plateau.
Storm Activities during the Sedimentation of Late Paleocene-Middle Eocene Subathu Formation, Western Himalayan Foreland Basin
Authors: Singh B. P. , Srivastava A. K.
Published: March 2011

Late Paleocene-middle Eocene Subathu Formation represents the earliest deposits of the western Himalayan foreland basin. A large part of this formation is comprised of impure limestone and grey shale intercalations. The limestones contain sole marks, intraformational conglomerates, hummocky cross stratification and wave ripples. The occurrence of sole marks suggests that they are developed by the unidirectional currents at the initial phase of the storm that resulted erosion and subsequent deposition. The intraformational limestone conglomearate also suggests erosion of the earlier deposited limestone hardgrounds as a consequence of storm associated transgression. The hummocky cross stratification formed by the oscillatory flows during the long-shore littoral drift. The depth of formation of the hummocky cross stratified limestone facies was less than 40 m and most likely deposited between shore-face to backshore regions of the gulf similar to present day Persian Gulf. The identification of deeper facies (shelf facies) from Pakistan and coastal facies from India suggest that the gulf was open from the west and closed from the east.
Drainage Basin Morphometry for Identifying Zones for Artificial Recharge: A Case Study from the Gagas River Basin, India
Authors: Zaidi Faisal K.
Published: March 2011

Drainage basin morphometry is a quantitative way of describing the characteristics of the surface form of a drainage basin and provides important information about the region’s topography and underlying geological structures. It plays an important role in hydrogeological investigations for delineating zones of adequate groundwater potential and selecting sites for construction of artificial recharge structures.

In the present study an attempt was made to discover the stream properties in the Gagas River Basin of Almora district in the state of Uttarakhand using the various stream attributes. Based on the study the potential zones for the construction of artificial recharge structures in the basin were identified.
Geomorphic and Structural Evidences of Neotectonic Activity in the Sub-Himalayan Belt of Nahan Salient, NW India
Authors: Singh Tejpal , Sharma Umakant , Awasthi A.K. , Virdi N.S. , Kumar Ravindra
Published: March 2011

Neotectonism in the Sub-Himalayan belt is not new. Moreover, the word ‘Sub-Himalaya’ is almost synonymous with ‘neotectonic activity’. In the present paper, we report some of the most convincing geomorphic and structural evidences of neotectonic activity from the Sub-Himalayan belt in the Nahan Salient. The geomorphic evidences mainly include the four geomorphic surfaces identified from the transverse topographic profiles drawn parallel to the Himalayan front. These surfaces are commonly covered with terrace deposits that are tilted as well as faulted at a number of places. A number of faults, directly observable in the field, are normal in nature and they are oriented at high angles to the Himalayan Frontal Thrust (HFT). These faults are similar to the E-W extension in southern Tibet in response to the oblique convergence of India at ~N20oE in the NW Himalaya. They are attributable to the kinematics of neotectonic compression along the HFT, the frontal ramp-oblique ramp-frontal ramp geometry of the thrust fault and related adjustments.
Branchial cleft cyst: an unusual ultrasound diagnosis in an austere environment
Authors: Ball Vincent L. , Barnwell Robert M. , Greene Jeffrey P.
Published: March 2011

Branchial cleft cysts are typically benign congenital cysts lined by epithelial cells that arise on the lateral part of the neck. Ultrasound is useful in situations, where CT scanning and MRI are unavailable. We report a case of a 29-year-old Ugandan male who presents with a unilateral neck mass. We highlight the usefulness of ultrasound in diagnosing a lesion consistent with a branchial cleft cyst, while ruling out other causes of neck masses.
MEK/ERKs signaling is essential for lithium‐induced neurite outgrowth in N2a cells
Authors: Wang Zhuyao , Wang Juan , Li Jingjin , Wang Xiaohui , Yao Yuzhen , Zhang Xiaojin , Li Chuanfu , Cheng Yunlin , Ding Guoxian , Liu Li , Ding Zhengnian
Published: March 2011

Lithium, a drug used for the treatment of bipolar disorder, has been shown to affect different aspects of neuronal development such as neuritogenesis, neurogenesis and survival. The underlying mechanism responsible for lithium's influence on neuronal development, however, still remains to be elucidated. In the present study, we demonstrate that lithium increases the phosphorylation of extracellular‐signal regulated kinases (ERKs) and protein kinase B (Akt) and promotes neurite outgrowth in mouse N2a neuroblastoma cells (N2a). The inactivation of mitogen‐activated protein kinase kinase (MEK)/ERKs signaling with a MEK inhibitor inhibits neurite outgrowth, but it enhances Akt activation in lithium‐treated N2a cells. Furthermore, the inactivation of phosphoinositide‐3‐kinase (PI3K)/Akt signaling with a PI3K inhibitor increases both lithium‐induced ERKs activation and lithium‐induced neurite outgrowth. Taken together, our study suggests that lithium‐induced neurite outgrowth in N2a cells is regulated by cross‐talk between the MEK/ERKs and PI3K/Akt pathways and requires the activation of the MEK/ERKs signaling.
Outcome of the management of massive postpartum hemorrhage using the algorithm “HEMOSTASIS”
Authors: Varatharajan Lavanya , Chandraharan Edwin , Sutton Julian , Lowe Virginia , Arulkumaran Sabaratnam
Published: March 2011

Objective

To evaluate whether the algorithm “HEMOSTASIS” (help; establish etiology; massage the uterus; oxytocin infusion and prostaglandins; shift to operating theater; tamponade test; apply compression sutures; systematic pelvic devascularization; interventional radiology; subtotal/total abdominal hysterectomy) was of value in the systematic management of postpartum hemorrhage (PPH).

Methods

A retrospective analysis was performed of all women who experienced massive primary PPH (blood loss > 1500 mL) in 2008 at St George's Hospital, London, UK. The success of the HEMOSTASIS mnemonic in PPH management was determined by assessing clinical outcome following adherence to the protocol.

Results

Patient notes were available for 95 (83.3%) of the 114 cases of primary PPH. Hemostasis was achieved in 63 (66.3%) women via use of additional oxytocics (“O”); 19 (20.0%) via suture of tears and 10 (10.5%) via tamponade (“T”); 1 (1.1%) via application of compression suture (“A”); 1 (1.1%) via systematic devascularization (“S”); and 1 (1.1%) via subtotal/total hysterectomy (“S”). There were no maternal deaths.

Conclusion

The decremental pattern of more complex interventions used demonstrates that the algorithm can provide a logical management pathway to reduce blood transfusions, hysterectomies, admissions to intensive care units, and maternal deaths.
Using Well-Plate Microfluidic Devices to Conduct Shear-Based Thrombosis Assays
Authors: Conant Carolyn G. , Nevill J. Tanner , Zhou Zhou , Dong Jing-Fei , Schwartz Michael A. , Ionescu-Zanetti Cristian
Published: March 2011

Shear stress plays a critical role in regulating platelet adhesion and thrombus formation at the site of vascular injury. As such, platelets are often examined in vitro under controlled shear flow conditions for their hemostatic and thrombotic functions. Common shear-based platelet analyses include the evaluation of genetic mutants, inhibitory or experimental compounds, matrix substrates, and the effects of different physiological and pathological shear forces. There are several laboratory instruments widely used for studying shear flow, including cone and plate viscometers and parallel plate perfusion chambers. These technologies vary widely in the types of samples, substrates, blood volumes, and throughput that are involved. Here, we describe a microfluidic system for platelet analysis under shear flow. We used the devices to study thrombus formation on collagen I and von Willebrand factor. The system was also used to investigate dose response to the antiplatelet compound, Abciximab, under shear flow conditions with an emphasis on maximizing the number of data points per single patient sample. The presented method confers multiple advantages over conventional approaches. These include the ability to assess up to 24 conditions simultaneously in real time, maintain identical physical conditions across experiments, and use extremely low donor volumes.