bluuebunny/crossref_metadata_2025 huggingface dataset:
Quadruple click reactions for the synthesis of cysteine‐terminated linear multiblock copolymers
Authors: Candan Ozlem Aldas , Durmaz Hakan , Hizal Gurkan , Tunca Umit
Published: April 2012

Synthesis of cysteine‐terminated linear polystyrene (PS)‐b‐poly(ε‐caprolactone) (PCL)‐b‐poly(methyl methacrylate) (PMMA)/or poly(tert‐butyl acrylate)(PtBA)‐b‐poly(ethylene glycol) (PEG) copolymers was carried out using sequential quadruple click reactions including thiol‐ene, copper‐catalyzed azide–alkyne cycloaddition (CuAAC), Diels–Alder, and nitroxide radical coupling (NRC) reactions. N‐acetyl‐L‐cysteine methyl ester was first clicked with α‐allyl‐ω‐azide‐terminated PS via thiol‐ene reaction to create α‐cysteine‐ω‐azide‐terminated PS. Subsequent CuAAC reaction with PCL, followed by the introduction of the PMMA/or PtBA and PEG blocks via Diels–Alder and NRC, respectively, yielded final cysteine‐terminated multiblock copolymers. By 1H NMR spectroscopy, the DPns of the blocks in the final multiblock copolymers were found to be close to those of the related polymer precursors, indicating that highly efficient click reactions occurred for polymer–polymer coupling. Successful quadruple click reactions were also confirmed by gel permeation chromatography. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Proton‐controlled nitroxide mediated radical polymerization of styrene
Authors: Le Du Yann , Binet Laurent , Hémery Patrick , Marx Lucien
Published: April 2012

The pyridyl alkoxyamine, which is composed of the 1‐phenylethyl radical and a pyridyl nitroxide fragments, displays protonation‐controlled CON bond homolysis. Its dissociation rate constant kd value is approximately halved at 100 °C in tert‐butyl benzene when it is protonated by one equivalent of trifluoroacetic acid. Moreover, the bulk polymerization of styrene at 125 °C is performed with a good control over the molecular weight and the dispersity when initiated with this alkoxyamine under its basic and acidic forms but the protonation has induced a strong decreased polymerization rate. In contrast, in the case of n‐butyl acrylate, the control over the polymerization is lost for the protonated pyridyl alkoxyamine because the pyridyl nitroxide is less thermally stable under its acidic form. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Modulating structural stability and acid sensitivity of photosensitive polymer micelles simply via one‐batch UV irradiation
Authors: Tang Yufang , Liu Zhilin , Wu Xuewen , Liu Guhuan , Yang Ke , Li Yaohua , Lu Lican , Cai Yuanli
Published: April 2012

This article describes the photosensitive polymer micelles whose structural stability and acid sensitivity can be widely tuned simply via one‐batch UV irradiation. To this end, the well‐defined poly(5‐ethyl‐5‐methacryloyloxy‐methyl‐2‐styryl‐[1,3]dioxane)‐block‐poly[poly(ethylene glycol) methacrylate] (PEMSD‐b‐PPEGMA) copolymers were synthesized via RAFT polymerization under mild visible light radiation at 30 °C. The results demonstrated that the irradiation of the homogeneous acetone solution with UV light only induced Z‐isomerization of their cinnamyl groups, while irradiating PEMSD chains in the bulky micellar cores only induced dimerization. Moreover, the micelles of previously Z‐isomerized copolymer could be effectively stabilized without changing their acid sensitivity on irradiating for shortly 3 min, while UV irradiation for 30 min could remarkably improve the acid stability of these micelles. These novel properties are of potential applications in controlled drug delivery. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Highly stereoselective coordination polymerization of β‐myrcene from a lanthanide‐based catalyst: Access to bio‐sourced elastomers
Authors: Loughmari Saliha , Hafid Abderrafia , Bouazza Aicha , El Bouadili Abdelaziz , Zinck Philippe , Visseaux Marc
Published: April 2012

Polymerization of β‐myrcene with neodymium borohydride‐based coordination catalysts is very efficient, affording poly‐β‐myrcene (polymyrcene, PMy) with high selectivity. With stoichiometric amounts of n‐butylethyl magnesium (BEM) as co‐catalyst, good control over macromolecular data along with cis‐stereoselectivity up to 98.5%, are obtained. In the presence of excess BEM, high level of transfer reactions efficiency between neodymium and magnesium is clearly evidenced whereas the selectivity switches to 3,4‐rich. Combining the neodymium pre‐catalyst with triisobutyl aluminum in the presence of a boron activator affords PMy in good yield, but the polymer material displays low solubility, likely due to the occurrence of crosslinking. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Benzodifuran‐containing well‐defined π‐conjugated polymers for photovoltaic cells
Authors: Li Hui , Tang Peng , Zhao Yan , Liu Shi‐Xia , Aeschi Yves , Deng Lijun , Braun Jörg , Zhao Bin , Liu Yunqi , Tan Songting , Meier Wolfgang , Decurtins Silvio
Published: April 2012

Two well‐defined alternating π‐conjugated polymers containing a soluble electroactive benzo[1,2‐b:4,5‐b′]difuran (BDF) chromophore, poly(BDF‐(9‐phenylcarbazole)) (PBDFC), and poly(BDF‐benzothiadiazole) (PBDFBTD) were synthesized via Sonogashira copolymerizations. Their optical, electrochemical, and field‐effect charge transport properties were characterized and compared with those of the corresponding homopolymer PBDF and random copolymers of the same overall composition. All these polymers cover broad optical absorption ranges from 250 to 750 nm with narrow optical band gaps of 1.78–2.35 eV. Both PBDF and PBDFBTD show ambipolar redox properties with HOMO levels of −5.38 and −5.09 eV, respectively. The field‐effect mobility of holes varies from 2.9 × 10−8 cm2 V−1 s−1 in PBDF to 1.0 × 10−5 cm2 V−1 s−1 in PBDFBTD. Bulk heterojunction solar cell devices were fabricated using the polymers as the electron donor and [6,6]‐phenyl‐C61‐butyric acid methyl ester as the electron acceptor, leading to power conversion efficiencies of 0.24–0.57% under air mass 1.5 illumination (100 mW cm−2). These results indicate that their band gaps, molecular electronic energy levels, charge mobilities, and molecular weights are readily tuned by copolymerizing the BDF core with different π‐conjugated units. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
DNA Damage in Mammalian Cells by Non‐thermal Atmospheric Pressure Microsecond Pulsed Dielectric Barrier Discharge Plasma is not Mediated by Ozone
Authors: Kalghatgi Sameer , Fridman Alexander , Azizkhan‐Clifford Jane , Friedman Gary
Published: April 2012

Non‐thermal dielectric barrier discharge (DBD) plasma is now being widely developed for various clinical applications1,2 but the mechanisms of interaction of such plasmas with mammalian cells are still not well understood. It is known that DBD plasma produces ozone and it is possible that the effects of plasma may be mediated purely by ozone. Although typically requiring much higher treatment time than the typical plasma treatment times reported here, ozonation is, in fact, widely employed to kill microorganisms in water and is also used for wound healing. It has been shown earlier that plasma treatment of mammalian cells submerged in a shallow layer of culture medium can result in dose dependent DNA damage. We wanted to understand the role of ozone in mediating the interaction of non‐thermal plasma DBD plasma with mammalian cells. Upon comparing plasma treatment of mammalian breast epithelial cells with ozone treatment we found that ozone treatment is qualitatively different from non‐thermal DBD plasma and in fact does not play a role in mediating the observed effects of plasma on mammalian cells.

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Glaucoma: guide to diagnosis and modern management
Authors: McAllister James
Published: April 2012

Chronic open angle glaucoma (COAG) is a common disease that may not be diagnosed until significant optic nerve damage has already occurred. Our Drug review provides useful tips in diagnosis and management, followed by an analysis of prescription data and sources of further information. Copyright © 2012 Wiley Interface Ltd
Bile acid diarrhoea: diagnosis and pharmacological treatment
Authors: Baburajan Bijay
Published: April 2012

Colonic exposure to bile acids through excessive secretion or defective reabsorption can lead to watery diarrhoea and should be considered in all cases of diarrhoea‐predominant IBS. Here, the author discusses the diagnosis of bile acid diarrhoea and its drug treatment. Copyright © 2012 Wiley Interface Ltd
Characterisation of polymeric materials as passivation layer for calorimetric H2O2 gas sensors
Authors: Kirchner Patrick , Reisert Steffen , Pütz Patrick , Keusgen Michael , Schöning Michael J.
Published: April 2012

Calorimetric gas sensors for monitoring the H2O2 concentration at elevated temperatures in industrial sterilisation processes have been presented in previous works. These sensors are built up in form of a differential set‐up of a catalytically active and passive temperature‐sensitive structure. Although, various types of catalytically active dispersions have been studied, the passivation layer has to be established and therefore, chemically as well as physically characterised. In the present work, fluorinated ethylene propylene (FEP), perfluoralkoxy (PFA) and epoxy‐based SU‐8 photoresist as temperature‐stable polymeric materials have been investigated for sensor passivation in terms of their chemical inertness against H2O2, their hygroscopic properties as well as their morphology. The polymeric materials were deposited via spin‐coating on the temperature‐sensitive structure, wherein spin‐coated FEP and PFA show slight agglomerates. However, they possess a low absorption of humidity due to their hydrophobic surface, whereas the SU‐8 layer has a closed surface but shows a slightly higher absorption of water. All of them were inert against gaseous H2O2 during the characterisation in H2O2 atmosphere that demonstrates their suitability as passivation layer for calorimetric H2O2 gas sensors.
Nutrient concentration‐sensitive microorganism‐based biosensor
Authors: Werner Carl Frederik , Groebel Simone , Krumbe Christoph , Wagner Torsten , Selmer Thorsten , Yoshinobu Tatsuo , Baumann Marcus E. M. , Keusgen Michael , Schöning Michael J.
Published: April 2012

This work presents a biosensor based on living cells immobilised on a light‐addressable potentiometric sensor (LAPS). The set‐up is sensitive to the concentrations of nutrients metabolised by bacteria, which results in an extracellular acidification. This is exemplarily demonstrated with glucose as nutrient and Escherichia coli as microorganism. The function of this biosensor is comparable to an enzyme‐based field‐effect sensor when using diffusion limitation. With the help of addressability of the LAPS an on‐chip differential set‐up was developed. Thus, external influences such as sensor drift, temperature and external pH changes can be minimised.
Approaches to the detection of whole cells using reflectometric interference spectroscopy
Authors: Merkl Stefan , Vornicescu Doru , Dassinger Nina , Kehrel Marcus , Harpel Susanne , Keusgen Michael
Published: April 2012

Methods for rapid and reliable detection of clinically relevant bacteria are of highest interest. For such purposes, many analytical methods, e.g. ELISA, have been developed. Also optical biosensors like reflectometric interference spectroscopy (RIfS) are suitable analytical platforms. Here, results are described to capture and detect Legionella pneumophila serogroup 1 on differently functionalized surfaces of RIfS glass chips. As a major problem, availability of suitable antibodies was found. Immobilization of capturing antibodies on the chip surface followed by trapping of L. pneumophila gave only insufficient results. For this approach, the chip surface was partially blocked with bovine serum albumin (BSA) in different ratios between BSA and the Legionella specific antibody in order to obtain a site‐directed immobilization. Further on, antibodies were immobilized by hydrophobic interaction followed by BSA treatment and exposition to L. pneumophila. However, also this approach did not allow sufficient capturing of bacteria cells. It can be assumed that binding forces between the antibody and bacteria are too low. Alternatively, L. pneumophila bacteria were directed immobilized on a hydrophobic chip surface. A sufficient sensor signal for quantification was obtained in a range between 8.25 × 106 and 8.25 × 108 bacteria cells/mL. This approach might open up the possibility for safe identification of L. pneumophila after subsequent addition of specific antibodies.
Influence of substrate resistivity on photovoltaic characteristics of Pd‐doped amorphous carbon film/SiO2/Si heterojunction
Authors: Xue Qingzhong , Wang Sheng , Li Jianpeng , Zhang Hongxin , Jiao Zhiyong
Published: April 2012

The Pd‐doped amorphous carbon (a‐C:Pd) film was deposited on n‐Si substrates with a native SiO2 layer to form a‐C:Pd film/SiO2/Si solar cell using a direct current magnetron sputtering method. We studied the effect of Si substrate resistivity on the photovoltaic characteristics of the a‐C:Pd film/SiO2/Si solar cell for the first time and found that the Si substrate resistivity has a marked effect on the photovoltaic characteristics of a‐C:Pd film/SiO2/Si heterojunctions. The heterojunction with n‐Si substrate resistivity of 2–3 Ω cm shows the highest open‐circuit voltage, short‐circuit current density, and conversion efficiency. A reasonable mechanism for the results is presented in this paper.
Optical characterization of gold chains and steps on the vicinal Si(557) surface: Theory and experiment
Authors: Hogan Conor , McAlinden Niall , McGilp John F.
Published: April 2012

We present a joint experimental‐theoretical study of the reflectance anisotropy of clean and gold‐covered Si(557), a vicinal surface of Si(111) upon which gold forms quasi‐one‐dimensional (1D) chains parallel to the steps. By means of first‐principles calculations, we analyse the close relationship between the various surface structural motifs and the optical properties. Good agreement is found between experimental and computed spectra of single‐step models of both clean and Au‐adsorbed surfaces. Spectral fingerprints of monoatomic gold chains and silicon step edges are identified. The role of spin–orbit coupling (SOC) on the surface optical properties is examined, and found to have little effect.
The correlation between the electron work function and yield strength of metals
Authors: Hua Guomin , Li Dongyang
Published: April 2012

In this study, an effort is made to establish the correlation between electron work function (EWF) and mechanical properties of metals such as yielding strength and hardness. In general, the intrinsic resistance of metals to plastic deformation depends on their atomic bond strength that is essentially governed by the electron behavior. Based on the Peierls–Nabarro model, an intrinsic sixth‐power dependence of the yield strength of metals on their EWF is derived. Such a relation can also be extended to hardness. The established correlations are verified by the reported experimental results of transition metals and rare‐earth metals.
Multiobjective Genetic Algorithm Approach to the Economic Statistical Design of Control Charts with an Application to bar and S2 Charts
Authors: Faraz Alireza , Saniga Erwin
Published: April 2012

Control charts are the primary tools of statistical process control. These charts may be designed by using a simple rule suggested by Shewhart, a statistical criterion, an economic criterion, or a joint economic statistical criterion. Each method has its strengths and weaknesses. One weakness of the methods of design listed is their lack of flexibility and adaptability, a primary objective of practical mathematical models. In this article, we explore multiobjective models as an alternative for the methods listed. These provide a set of optimal solutions rather than a single optimal solution and thus allow the user to tailor their solution to the temporal imperative of a specific industrial situation. We present a solution to a well‐known industrial problem and compare optimal multiobjective designs with economic designs, statistical designs, economic statistical designs, and heuristic designs. Copyright © 2012 John Wiley & Sons, Ltd.
A wireless sensor network framework based on light databases
Authors: Cañete Eduardo , Díaz Manuel , Rubio Bartolomé
Published: April 2012

The development of wireless sensor and actor network applications is made difficult by the fact that developers have to face up to a set of resource‐constrained devices which have to work wirelessly and distributely. In this work, we propose a framework to create and integrate light databases within nodes that need to manage and process data. The databases will be designed by means of simple entity‐relationship models from which the code needed to manage the database will be generated. Basically, this code will be composed of data structures and the algorithms in charge of managing them. This architecture will help developers avoid data redundancy to better manage the memory of the nodes and to save time in developing applications. Copyright © 2012 John Wiley & Sons, Ltd.
A survey of computational molecular science using graphics processing units
Authors: Harvey M. J. , De Fabritiis Gianni
Published: April 2012

Computational molecular science is a very computationally intense discipline, and the use of parallel programming and high‐performance computers well established as being necessary to support research activities. Recently, graphical processing units (GPUs) have garnered substantial interest as alternative sources of high‐performance computing capability. These devices, although capable of very high rates of floating‐point arithmetic, are also intrinsically highly parallel processors and their effective exploitation typically requires extensive software refactoring and development. Here, we review the current landscape of GPU hardware and programming models, and provide a snapshot survey of the current state of computational molecular science codes ported to GPUs to help domain scientists and software developers understand the potential benefits and drawbacks of this new computing architecture. © 2012 John Wiley & Sons, Ltd.

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Computer and Information Science > Computer Algorithms and Programming
An investigation of radial velocities for a horizontal axis wind turbine in axial and yawed flows
Authors: Micallef Daniel , van Bussel Gerard , Ferreira Carlos Simão , Sant Tonio
Published: April 2012

An experimental and numerical analysis of radial flows in the near wake of a horizontal axis wind turbine is presented for both axial and yawed turbine conditions. Blade performance and wake development are affected because of radial velocities. The phenomenon has not been previously detailed, and current knowledge is limited to the mid to far wake regions. The stereo particle image velocimetry dataset of the model experiments in controlled conditions (MEXICO) rotor is used along with a 3D unsteady potential‐flow panel model. The latter is used, after validation, to give a complete description of the radial velocities and give insight into wake development and geometry. For both axial and yawed flows, the radial velocity is found to increase from root to tip with some complex behaviour in the root and tip regions. For axial flow, radial velocities were found to be appreciable. For yawed flow, because of the in‐plane freestream component, radial velocities are of the scale of the unperturbed flow especially when the blade is in its leeward and windward positions. The implications of this study are particularly relevant for blade element momentum analysis tools that rely on a purely 2D momentum balance approach. Moreover, this study enables further understanding of the wake development process in the proximity of the rotor. Copyright © 2012 John Wiley & Sons, Ltd.
Multiplicities from black-hole formation in heavy-ion collisions
Authors: Kiritsis Elias , Taliotis Anastasios
Published: April 2012

Abstract

The formation of trapped surfaces in the head-on collision of shock waves in conformal and non-conformal backgrounds is investigated. The backgrounds include all interesting confining and non-confining backgrounds that may be relevant for QCD. Several transverse profiles of the shocks are investigated including distributions that fall-off as powers or exponentials. Different ways of cutting-off the UV contributions (that are expected to be perturbative in QCD) are explored. Under some plausible simplifying assumptions our estimates are converted into predictions for multiplicities for heavy-ion collisions at RHIC and LHC.
On “new massive” 4D gravity
Authors: Bergshoeff Eric A. , Fernández-Melgarejo J. J. , Rosseel Jan , Townsend Paul K.
Published: April 2012

Abstract

We construct a four-dimensional (4D) gauge theory that propagates, unitarily, the five polarization modes of a massive spin-2 particle. These modes are described by a “dual” graviton gauge potential and the Lagrangian is 4th-order in derivatives. As the construction mimics that of 3D “new massive gravity”, we call this 4D model (linearized) “new massive dual gravity”. We analyse its massless limit, and discuss similarities to the Eddington-Schrödinger model.
Desynchronization and re‐synchronization of reproduction by Astragalus scaphoides, a plant that flowers in alternate years
Authors: Crone Elizabeth E.
Published: April 2012

Mast seeding, the synchronous seed production by plants at irregular intervals, has been widely studied from the perspective of its fitness benefits, but much less is known about the proximate factors that cause plants to reproduce synchronously. In this article, I follow up on more than two decades of research investigating proximate mechanisms of mast seeding by Astragalus scaphoides, an iteroparous perennial forb. We use long‐term monitoring in relation to two environmental manipulations to evaluate the importance of exogenous environmental factors versus endogenous feedbacks for synchrony in this species. Our past research showed that synchrony in this species is explained by the pollen‐coupling hypothesis: plants that flower synchronously set seed and deplete stored resources, whereas plants that happen to flower asynchronously are pollen limited, set fewer seeds, and do not deplete resources, and flower again until they are resynchronized. Continued monitoring of two experimental manipulations, water addition, and flower removal, provides additional support for this model, and also reveals subtle effects of water availability on synchrony. Water addition decreased flowering, rather than increasing it as expected based on simple correlations with weather variables, suggesting that precipitation does not synchronize reproduction. Exogenous drivers are generally considered to be the primary synchronizing factors in plant reproduction. Our work in this system suggests that endogenous feedbacks may be more important than has been previously assumed.
In Vitro Elution Characteristics of Vancomycin in a Composite Calcium Phosphate/Calcium Sulfate Bone Substitute
Authors: Yang Xu , Osagie Liza , Bostrom Mathias P.
Published: April 2012

Background

Periprosthetic joint infection is a particularly difficult orthopedic problem, complicating a growing number of revision procedures. Joint debridement and systemic antibiotics are the mainstay of treatment, yet difficulty remains in maintaining a minimum inhibitory concentration of antibiotic at the localized site of infection.

Study Aims

This study analyzes the elution characteristics of a 40%bwt calcium phosphate–60%bwt calcium sulfate composite, at varying concentrations of vancomycin.

Methods

Four groups of varying concentrations of vancomycin (2.63%bwt, 5.13%, 9.76%, and 17.78%) were mixed with one pack of the composite cement. At designated time intervals up to 28 days, the antibiotic concentration was detected using fluorescence polarization immunoassay and the elution trends compared.

Results

The elution rate of each of the four groups decreased over time. At almost all of the intervals, the elution rates of the higher concentration groups were significantly higher than the lower concentration groups ( P < 0.05).

Conclusions

Calcium sulfate reabsorbs over a prolonged period, producing porosity which allows for new bone ingrowth through occupation of osteoprogenitor cells and osteoblasts; while calcium phosphate acts as a long-term osteoconductive matrix.

Clinical Relevance

The results of this study suggest that vancomycin can be mixed affectively with a calcium sulfate/phosphate composite, both maintaining stability and eluting gradually over a clinically relevant period of time.
Total Hip Arthroplasty at the Rothman Institute
Authors: Austin Matthew S. , Higuera Carlos A. , Rothman Richard H.
Published: April 2012

Background

Total hip arthroplasty (THA) is one of the most successful surgical interventions devised in modern times. Attempts to change the current THA procedure with unproven innovations bring the risk of increased failure rates while trying to improve the benefit of the surgery.

Questions/Purposes

This manuscript examines the evolution of THA at the Rothman Institute illustrating the key elements that lead the success of this procedure at this institution. These key elements include femoral stem design, use of highly crossed-linked polyethylene and use of pain and rehabilitation protocols. We attempted to describe the long-term results regarding safety, effectiveness, and durability of specific THA implant designs used at this institution drawing on reported evidence in the literature.

Methods

The authors performed a review of peer-reviewed articles related to the Rothman Institute's experience with THA.

Results

Total hip arthroplasty is an efficient, safe, and durable procedure. It is a highly successful operation to restore function and improve pain. The survivorship of THA procedures at the Rothman Institute is higher than 99% at 10 years based on mechanical failure. The use of collarless, tapered wedge femoral stem, highly crossed-linked polyethylene, and improved pain rehabilitation protocols have contributed to this success.

Conclusions

There is a well-documented long-term survivorship after THA. Future innovation in THA should address new challenges with younger and more demanding patients, rather than change current methods that have a proven good survivorship. This innovation depends mainly upon improvements in the bearing surfaces and advances in pain control and rehabilitation.
Changes in Landuse and Landcover along the Dhansiri River Channel, Assam – A Remote Sensing and GIS Approach
Authors: Kotoky P. , Dutta M. K. , Borah G. C.
Published: April 2012

Information on landuse/landcover change is a critical input for natural resource management policy decisions. Remote sensing data under GIS domain were utilized to evaluate the changes in land-use/land-cover (LU/LC) spanning a period of thirty three years during 1975 to 2008 along the Dhansiri River channel, Assam, India. Seven different types of LU/LC were categorized and out of them cropland was evident as the most important landuse/landcover practices followed by dense mixed jungle in 1975 and the settlement in 2008. Significant reduction (13.02%) in cropland area to settlement was observed. Moreover, teagarden also occupies 0.77% of the total area from cropland and open mixed jungle. The changes in the areas of swampy land as evident from the present study in turn will impact the environmental quality around it and will help to increase the surface run off leading to enhancement of erosion processes. It is believed that the present study will help to contribute towards sustainable land-use planning and management towards protection of extremely rich biodiversity of the North East India with mighty Brahmaputra River system.
A Fossil Palm Leaf Impression from ~11.2 Ma Old, Siwalik Deposits of Kangra Valley, Himachal Pradesh
Authors: Singh Ram Ratan , Patnaik Rajeev
Published: April 2012

We report here, a fossil palm leaf from Lower Siwalik sediments, tied to nearby palaeomagnetically dated 11.2 Ma old beds exposed in the Baner Khad, near Ranital, Himachal Pradesh. The palm fossil leaf impression has been placed in the genus Palmacites sp. (Family: Arecaceae) based on its diagnostic features such as large palmate leaf without hastula and costa (midrib), showing coriaceous texture, leaflets diverging from the base of the lamina with prominent midrib and parallel venation. This finding may indicate presence of tropical to subtropical climatic conditions in the Himalayan foothills around Kangra Valley in the Middle Miocene time.
High Resolution Facies Record on Late Holocene Flood Plain Sediments from Lower Reaches of Narmada Valley, Western India
Authors: Sukumaran Prabhin , Sant Dhananjay A. , Krishnan K. , Rangarajan Govindan
Published: April 2012

A high resolution quantitative granulometric record for site Uchediya [21°43'2.22" N, 73° 6'26.22" E; 10 m a. s. l.] gives understanding towards accretion history of the late Holocene flood plain in the lower reaches of Narmada River. Two sediment facies (sandy and muddy) and seven subfacies (sandy subfacies: StMS+FS+CS, SmFS+MS, SlFS+VFS, and StMS + CS; muddy subfacies: FmSILT+VFS+FS, FmSILT+VFS+FS (O) and FmSILT+VFS+FS (T)) are identified based on cluster analysis supplemented with sedimentary structures observed in field and other laboratory data. Changes in hydrodynamics are further deduced based on various sedimentological parameters and their ratios leading to arrive at a depositional model.
Velocity and velocity gradient based properties of a turbulent plane mixing layer
Authors: Loucks Richard B. , Wallace James M.
Published: April 2012

Experiments were carried out in a turbulent mixing layer designed to match, as closely as possible, the conditions of the temporally evolving direct numerical simulation of Rogers & Moser (Phys. Fluids, vol. 6, 1994, pp. 903–922). Two Reynolds numbers, based on the local momentum thickness in the self-similar region of the mixing layer, were investigated:${R}_{\theta } = 1792$and$2483$. Measurements were also made in the mixing layer in the pre-mixing transition region where${R}_{\theta } = 432$. The three velocity components and their cross-stream gradients were measured with a small 12-sensor hot-wire probe that traversed the mixing layer. Taylor’s hypothesis was used to estimate the streamwise gradients of the velocity components so that reasonably good approximations of all the components of the velocity gradient tensor would be available. The signal from a single-sensor probe at a fixed position in the high-speed free stream flow provided a reference to the phases of the passage of large-scale, coherent, spanwise-oriented vortices past the 12-sensor probe. The velocity and velocity gradient data were analysed to determine turbulence statistical characteristics, including moments, probability density functions and one-dimensional spectra of the velocity and vorticity fields. Although the velocity statistics obtained from the experiment agree well with those from the direct numerical simulation of Rogers & Moser, there are significant differences in the vorticity statistics. The phase reference from the fixed single-sensor probe permitted phase averaging of the 12-sensor probe data so that the spanwise ‘roller’ vortices could be separated from the small-scale, more random turbulence, as had been previously demonstrated by Hussain & Zaman (J. Fluid Mech., vol. 159, 1985, pp. 85–104). In this manner, the data could be conditionally averaged to examine the spatial distributions, with respect to the roller vortices, of interesting and important characteristics of the turbulence, such as the turbulent kinetic energy production and dissipation rate, enstrophy and vorticity component covariances.
Dynamic -equation model for large-eddy simulation of compressible flows
Authors: Chai Xiaochuan , Mahesh Krishnan
Published: April 2012

This paper presents a dynamic one-equation eddy viscosity model for large-eddy simulation (LES) of compressible flows. The transport equation for subgrid-scale (SGS) kinetic energy is introduced to predict SGS kinetic energy. The exact SGS kinetic energy transport equation for compressible flows is derived formally. Each of the unclosed terms in the SGS kinetic energy equation is modelled separately and dynamically closed, instead of being grouped into production and dissipation terms, as in the Reynolds averaged Navier–Stokes equations. All of the SGS terms in the filtered total energy equation are found to reappear in the SGS kinetic energy equation. Therefore, these terms can be included in the total energy equation without adding extra computational cost.A prioritests using direct numerical simulation (DNS) of decaying isotropic turbulence show that, for a Smagorinsky-type eddy viscosity model, the correlation between the SGS stress and the model is comparable to that from the original model. Also, the suggested model for the pressure dilatation term in the SGS kinetic energy equation is found to have a high correlation with its actual value. Ina posterioritests, the proposed dynamic$k$-equation model is applied to decaying isotropic turbulence and normal shock–isotropic turbulence interaction, and yields good agreement with available experimental and DNS data. Compared with the results of the dynamic Smagorinsky model (DSM), the$k$-equation model predicts better energy spectra at high wavenumbers, similar kinetic energy decay and fluctuations of thermodynamic quantities for decaying isotropic turbulence. For shock–turbulence interaction, the$k$-equation model and the DSM predict similar evolutions of turbulent intensities across shocks, owing to the dominant effect of linear interaction. The proposed$k$-equation model is more robust in that local averaging over neighbouring control volumes is sufficient to regularize the dynamic procedure. The behaviour of pressure dilatation and dilatational dissipation is discussed through the budgets of the SGS kinetic energy equation, and the importance of the dilatational dissipation term is addressed.
SAYYIDA ZAYNAB IN THE STATE OF EXCEPTION: SHIʿI SAINTHOOD AS “QUALIFIED LIFE” IN CONTEMPORARY SYRIA
Authors: Szanto Edith
Published: April 2012

According to Giorgio Agamben, a “state of exception” is established by the sovereign's decision to suspend the law, and the archetypical state of exception is the Nazi concentration camp. At the same time, Agamben notes that boundaries have become blurred since then, such that even spaces like refugee camps can be thought of as states of exception because they are both inside and outside the law. This article draws on the notion of the state of exception in order to examine the Syrian refugee campcumshrine town of Sayyida Zaynab as well as to analyze questions of religious authority, ritual practice, and pious devotion to Sayyida Zaynab. Though Sayyida Zaynab and many of her Twelver Shiʿi devotees resemble Agamben's figure ofhomo sacer, who marked the origin of the state of exception, they also defy Agamben's theory that humans necessarily become animal-like, leading nothing more than “bare lives” (orzoē) in states of exception.
BEING A NONBELIEVER IN A TIME OF ISLAMIC REVIVAL: TRAJECTORIES OF DOUBT AND CERTAINTY IN CONTEMPORARY EGYPT
Authors: Schielke Samuli
Published: April 2012

Looking at the trajectories of people of Muslim origin in Egypt who express religious doubts, I argue in this article that doubt and nonreligiosity are not necessarily a child of a Christian genealogy of the secular and definitely not alien to Muslims. Instead, we have to understand them as an intimate moral discontent with the contemporary age of Islamic revival, even if their shape and some of their positive claims are borrowed from notions of Western origin and global currency—most notably, human rights and feminism. There are reasons and ways to become a nonbeliever in a society profoundly affected by a religious revival, and these reasons and ways can be telling about the nature of doubt and certainty in general. They also offer a perspective on the problematic of secularism that focuses on issues of belief and existential trust rather than governmentality and discursive power.
Rethinking Identity, Citizenship, and Violence in Sudan
Authors: Idris Amir
Published: April 2012

Since its political independence in 1956, Sudan has witnessed the rise of armed ethnic and regional protest movements that have resulted in great human suffering and the largest number of refugees and displaced peoples in Africa. These protest movements have challenged the legitimacy of the independent Sudanese state, led by Arabized and Islamized elites at the pinnacle of power, to extend and define citizenship rights and responsibilities. In Darfur, Southern Kordofan, and Blue Nile, these movements are not only currently demanding equal citizenship rights, but they are also demanding recognition of special rights including claims to land, autonomous government, and the maintenance of ethno-national identities. They are thus opening up a debate about what citizenship entails, particularly in a multicultural context; how the current state reconciles competing claims of citizenship; and what kinds of viable institutional mechanisms are required for an effective relationship between the state, its citizens, and local power structures.
Wildlife tourists in India's emerging economy: potential for a conservation constituency?
Authors: Karanth Krithi K. , DeFries Ruth , Srivathsa Arjun , Sankaraman Vishnupriya
Published: April 2012

Wildlife tourism is a growing phenomenon, particularly in emerging economies such as India. Purported benefits of this growth in tourism include greater tourist interest in, and support for, conservation. We examined the interest, awareness and potential for this support in three prominent Indian national parks, Nagarahole, Kanha and Ranthambore. Park records indicate that most tourists (71%) are Indian nationals. Our surveys of 436 Indian tourists indicate that many were on their first visit to the park (71%) and are well educated (82% with bachelor and master degrees). Most tourists (88%) visited for <1 week and spent <USD 600 on their visit. The main reasons for visiting parks were opportunities to see nature, tigersPanthera tigrisand scenic beauty. Seventy-one percent of tourists indicated they are likely or somewhat likely to return to the parks but only 34% would be willing to visit the parks if tigers are absent. Forty-two percent indicated willingness to pay higher gate fees. Surprisingly, those spending less on their trip were more willing to pay higher fees than those spending more. Sixty-five percent believed that local people benefit from the park, whereas in reality local benefits are few. Our results indicate the potential for the growth of domestic wildlife tourism and support for conservation among tourists but highlight the need for increasing education and awareness on the difficult realities of conservation in India.
Jaguar Panthera onca predation of marine turtles: conflict between flagship species in Tortuguero, Costa Rica
Authors: Veríssimo D. , Jones D. A. , Chaverri R. , Meyer S. R.
Published: April 2012

Predation can be an important driver of population dynamics but can also pose a dilemma to conservation managers if the species interacting are of conservation concern or have a high public profile. For 5 years we conducted regular transect surveys to monitor the spatial and temporal patterns of predation of adult marine turtles by jaguars Panthera onca in Tortuguero National Park, Costa Rica. Predation occurs throughout the study site on Tortuguero Beach although at lower rates at the northern and southern ends, probably because of increased human presence in these areas. There was a marked increase in predation, from an average of < 2 turtles predated per survey in the first season to > 5 predated per survey in the last, with 676 jaguar-predated marine turtles recorded during the study period. With a minimum of 189 individuals predated in the last season, predation of adult turtles has now reached a magnitude never before recorded in a marine turtle rookery. Although the nesting population of marine turtles in Tortuguero is one of the largest in the world and suffers from both direct and indirect anthropogenic pressures, the increase in predation by jaguars makes this ecological interaction relevant to the management of both the jaguar and marine turtle populations. The situation could lead to a potential conflict in conservation strategies that, given the flagship role of the species involved, will need to be addressed both in the context of species management and conservation marketing.
Evidence that the wider social environment moderates the association between familial liability and psychosis spectrum outcome
Authors: Binbay T. , Drukker M. , Alptekin K. , Elbi H. , Tanık F. Aksu , Özkınay F. , Onay H. , Zağlı N. , van Os J.
Published: April 2012

Background

Familial liability to both severe and common mental disorder predicts psychotic disorder and psychotic symptoms, and may be used as a proxy in models examining interaction between genetic risk and the environment at individual and contextual levels.

Method

In a representative general population sample (n=4011) in Izmir, Turkey, the full spectrum of expression of psychosis representing (0) no symptoms, (1) subclinical psychotic experiences, (2) low-impact psychotic symptoms, (3) high-impact psychotic symptoms and (4) full-blown clinical psychotic disorder was assessed in relation to mental health problems in the family (proxy for familial liability) and the wider social environment. Quality of the wider social environment was assessed in an independent sample using contextual measures of informal social control, social disorganization, unemployment and low income, aggregated to the neighbourhood level.

Results

The association between familial liability to severe mental illness and expression of psychosis spectrum was stronger in more deprived neighbourhoods [e.g. this association increased from β=0.33 (p=0.01) in low-unemployment neighbourhoods to β=0.92 (p<0.001) in high-unemployment neighbourhoods] and in neighbourhoods high in social control, while neighbourhood variables did not modify the association between familial liability to common mental disorder and the psychosis outcome. Neighbourhood variables mediated urbanicity effects.

Conclusions

Contextual effects may be important in moderating the expression of psychosis liability in populations, representing a specific pathway independent of the link between common mental disorder and psychosis.
Internal perturbations of homoclinic classes: non-domination, cycles, and self-replication
Authors: BONATTI CH. , CROVISIER S. , DÍAZ L. J. , GOURMELON N.
Published: April 2012

Conditions are provided under which lack of domination of a homoclinic class yields robust heterodimensional cycles. Moreover, so-called viral homoclinic classes are studied. Viral classes have the property of generating copies of themselves producing wild dynamics (systems with infinitely many homoclinic classes with some persistence). Such wild dynamics also exhibits uncountably many aperiodic chain recurrence classes. A scenario (related with non-dominated dynamics) is presented where viral homoclinic classes occur. A key ingredient are adapted perturbations of a diffeomorphism along a periodic orbit. Such perturbations preserve certain homoclinic relations and prescribed dynamical properties of a homoclinic class.
Pointwise ergodic theorems beyond amenable groups
Authors: BOWEN LEWIS , NEVO AMOS
Published: April 2012

We prove pointwise and maximal ergodic theorems for probability-measure-preserving (PMP) actions of any countable group, provided it admits an essentially free, weakly mixing amenable action of stable typeIII$_1$. We show that this class contains all irreducible lattices in connected semi-simple Lie groups without compact factors. We also establish similar results when the stable type isIII$_\lambda $,$0 \lt \lambda \lt 1$, under a suitable hypothesis. Our approach is based on the following two principles. First, we show that it is possible to generalize the ergodic theory of PMP actions of amenable groups to include PMP amenable equivalence relations. Secondly, we show that it is possible to reduce the proof of ergodic theorems for PMP actions of a general group to the proof of ergodic theorems in an associated PMP amenable equivalence relation, provided the group admits an amenable action with the properties stated above.
Asymmetries in the intonation system of the tonal dialect of Maastricht Limburgish
Authors: Gussenhoven Carlos
Published: April 2012

The lexical tone and intonation contrasts in the Limburgish dialect of Maastricht are remarkable in a number of ways. While a falling pitch contour on an IP-medial syllable signals a non-declarative intonation, on an IP-final syllable it signals a declarative intonation. In addition, although there is a binary tone contrast (Accent 1vs. Accent 2) and four nuclear intonation contours, only three intonation contours exist for nuclear syllables with Accent 2, while in IP-final position only two intonation contours exist for nuclear syllables with Accent 1, so that the full set of four intonation contours is only observable in IP-medial nuclear syllables with Accent 1. The context-dependent function of the pitch fall and the asymmetries are explained by a grammar in which the OCP is enforced absolutely, and the number of tones per syllable is restricted to two, unless the three tones each represent a different morpheme: OCP, Realise.orph≫#TTT.
Questioning the universality of the syllable: evidence from Japanese
Authors: Labrune Laurence
Published: April 2012

This paper reexamines the issue of the mora, the foot and the syllable in Tokyo Japanese, and shows that whereas the mora and the foot are indisputably present and active, the evidence for the syllable is inconspicuous and disputable. Building on this observation, I claim that Tokyo Japanese makes no use of the syllable. Instead, two types of mora are distinguished: regular CV moras and weak (deficient) moras. Weak moras include the moraic nasal, the first part of a geminate and the second part of a long vowel, as well as moras containing an onsetless vowel, a devoiced vowel or an epenthetic vowel. I further argue that feet obey a set of structural constraints stipulating that they be properly headed by a regular full mora. With this enriched notion of mora type, the paper argues that neither the syllable nor any other level of the prosodic hierarchy is obligatory in all languages.
What do we mean by mission? A consideration of Re Holy Trinity, Horwich
Authors: Shelley Catherine
Published: April 2012

The recent judgment in Re Holy Trinity Horwich in Manchester Consistory Court raises some interesting questions about the interpretation of mission in the application of the Bishopsgate questions. Thanks to the tests posed by the Bishopsgate questions, arising from the cases of Re St Helen Bishopsgate and Re St Luke the Evangelist Maidstone, the law governing faculty applications requires that the status quo be preserved in cases of church buildings with ‘special architectural and historical interest’ unless outweighed by the ‘necessity’ of ‘the pastoral well-being of the parish or some other compelling reason’.
Surgical repair of atrial septal defect with severe pulmonary hypertension during pregnancy: a case report with literature review
Authors: Manivannan Suganya , Dadlani Gul , Parsons Michael , Crisan Luminita , Belogolovkin Victoria , Sastry Narendra , Guglin Maya
Published: April 2012

We are reporting a case of a 37-year-old pregnant woman with a large secundum atrial septal defect with left-to-right shunt and severe pulmonary hypertension. Her atrial septal defect was undiagnosed before this pregnancy. After carefully considering all the options, we repaired her atrial septal defect with an open heart surgical closure at 20 weeks of gestation. A substantial and consistent reduction in pulmonary arterial pressure after the surgery and subsequent uneventful delivery indicate that surgical repair of atrial septal defects is a viable option that should be considered for such patients.