bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a hybrid neural network model to predict feeding method in fed‐batch cultivation for enhanced recombinant streptokinase productivity in Escherichia coli
Authors: Geethalakshmi Sundaresan , Narendran Sekar , Pappa Natarajan , Ramalingam Subramanian
Published: August 2011

BACKGROUND: A simple and efficient model for enhancing production of recombinant proteins is essential for cost effective development of processes at industrial scale. A hybrid neural network (HNN) model is proposed combining an unstructured model and neural network to predict the feeding method for the post‐induction phase of fed‐batch cultivation for increased recombinant streptokinase activity in Escherichia coli.

RESULTS: The parameters of the unstructured model were estimated from experiments conducted with various feeding methods. The simulated model described the dynamics of the process satisfactorily, however, its predictive capability of the process for different feeding methods is limited due to wide disparity in process parameters. In contrast, a neural network model trained to map the variations in process parameters to state variables complements the ‘first principle’ model in predicting the state variables effectively.

CONCLUSIONS: The HNN model is able to predict the product profile for different substrate feed rates. Further, the average volumetric streptokinase activity predicted by the HNN model matches closely the experimental values for fed‐batches having high as well as low streptokinase activity. The HNN model developed in this study could facilitate development of a process for recombinant protein production with minimum number of experiments. Copyright © 2011 Society of Chemical Industry
First evidence of a cDNA encoding for a melatonin receptor (mel 1b) in brain, retina, and testis of Pelophylax esculentus
Authors: Serino Ismene , Izzo Gaia , Ferrara Diana , Minucci Sergio , d'Istria Michela
Published: August 2011

Melatonin, nocturnally secreted by the pineal gland, regulates a variety of physiological functions, including reproduction. Here, we investigated the evidence of melatonin binding sites in frog tissue (brain, retina, and testis) through saturation and competition binding experiments. In the frog, Pelophylax esculentus, our results confirm the presence of a single class of melatonin‐specific binding sites in the brain and retina, but not in the testis. Further experiments have been done using biomolecular approaches (PCR analysis). Here, we report the isolation of a cDNA encoding for a melatonin receptor type (mel1b) from brain, retina, and testis of the P. esculentus. PCR analysis revealed that melatonin expression is higher in the brain and retina, whereas it is lower in the testis. The presence of a melatonin receptor transcript in the frog testis corroborates our previous results obtained in in vitro experiments that suggest that melatonin might act directly in male vertebrate gonads, and indicates that the frog testis may be a suitable model to verify the role of indolamine in testicular activity. J. Exp. Zool. 315:520–526, 2011. © 2011 Wiley Periodicals, Inc.
LESSONS FROM THE UNFINISHED AGENDA OF A SMALL DEVELOPING ECONOMY UNDER TRADE AND STRUCTURAL REFORMS
Authors: Mahadevan Renuka , Asafu‐Adjaye John
Published: August 2011

This article examines the issue of trade reforms confronting many African Caribbean and Pacific countries such as Fiji, which are set to lose their European Union sugar price subsidy at the end of 2007. It was found that attempts to offset the adverse impacts of the subsidy removal by targeting to improve the performance of any particular sector are counterproductive. Although the optimal policy for Fiji is a broad‐based diversification of exports, it is further argued that small developing economies need to address supply‐side constraints so that structural reforms can effectively sustain the economy's competitiveness in an increasingly globalised world economy. Copyright © 2011 John Wiley & Sons, Ltd.
A Simple Scheme for Grafting an Ion‐Imprinted Layer onto the Surface of Poly(propylene) Fibers
Authors: Li Tongyi , Wu Lei , Chen Shuixia , Li Haichao , Xu Xiuzhu
Published: August 2011

A simple method for surface ion‐imprinting is described in which poly(glycidyl methacrylate) is grafted onto PP fibers to act as a binder to a Cu2+ ion‐imprinted polymer layer. Mechanical and thermal analysis shows excellent tensile and thermal properties of the ion‐imprinted fibers. Competitive adsorption of Cu2+ and other ions such as Zn2+, Ni2+, Cd2+, Mn2+, and Mg2+ on the fibes is examined and a highly selective adsorption of Cu2+ is observed. The selectivity coefficient for Cu2+ with respect to Cd2+ can be as high as 20.2. Dynamic adsorption results indicate that the fibers are able to thoroughly remove Cu2+ from a solution. Regeneration performance tests show that the fibers maintain almost the same adsorption capacity for copper ions after 10 adsorption/desorption cycles.

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Thermally Curable Polyoxanorbornene by Ring Opening Metathesis Polymerization
Authors: Tasdelen Mehmet Atilla , Durmaz Hakan
Published: August 2011

A novel norbornene monomer bearing a thermally curable benzoxazine group is synthesized and polymerized by ROMP using the Grubbs first‐generation ruthenium catalyst. The $\overline {M} _{{\rm w}} $ of the side‐chain benzoxazine functionalized polyoxanorbornene can be up to 87 000 Da with unimodal molecular‐weight distribution and narrow polydispersity between 1.18 and 1.65. Thermally activated ring‐opening polymerization of benzoxazine moieties leads to the formation of highly cross‐linked structures. The effects of molecular weight on the thermal ROP of polybenzoxazine precursors are examined.

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Measurement Protocols for Reporting PEDOT Thin Film Conductivity and Optical Transmission: A Critical Survey
Authors: Fabretto Manrico , Zuber Kamil , Jariego‐Moncunill Carlos , Murphy Peter
Published: August 2011

PEDOT is one of the most frequently studied conducting polymers in literature but values for optical transmission and electrical conductivity vary greatly. Therefore measurement protocols are examined and insights are suggested into why the protocols themselves may lead to differences. Reported PEDOT conductivity is the result of contact and non‐contact film thickness and four‐point probe measurements. The soft nature of PEDOT implies that any contact method must be executed with extreme care as values of conductivity ranging from 780 to 2 775 S · cm−1 can be obtained. Similarly, variations in the optical minimum, maximum, and transmission range are found based on different switching voltage protocols. The results present here highlight the need for explicitly stating the measurement protocol used.

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Rotundity and uniform rotundity of Orlicz‐Lorentz sequence spaces equipped with the Orlicz norm
Authors: Wang Jincai , Ning Zhe
Published: August 2011

In this paper, we shall give a criteria of the rotundity and uniform rotundity of Orlicz‐Lorentz sequence spaces equipped with the Orlicz norm.
Lp‐Liouville property for non‐local operators
Authors: Masamune Jun , Uemura Toshihiro
Published: August 2011

The Lp‐Liouville property of a non‐local operator \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathcal {A}$\end{document} is investigated via the associated Dirichlet form \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$({\mathcal E},{\mathcal F})$\end{document}. We will show that any non‐negative continuous \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}${\mathcal E}$\end{document}‐subharmonic function \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$f \in {\mathcal F}_{\rm loc} \cap L^p$\end{document} are constant under a quite mild assumption on the kernel of \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}${\mathcal E}$\end{document} if p ≥ 2. On the contrary, if 1 < p < 2, we need an additional assumption: either, the kernel has compact support; or f is Hölder continuous.
Thiol‐alkyne Chemistry for the Preparation of Micelles with Glycopolymer Corona: Dendritic Surfaces versus Linear Glycopolymer in Their Ability to Bind to Lectins
Authors: Kumar Jatin , Bousquet Antoine , Stenzel Martina H.
Published: August 2011

A poly(tert‐butyl acrylate) (P(tBA)) with a glycodendric endfunctionality with eight glucose moieties was synthesised in four steps via a combination of esterification, thiol‐alkyne conjugation and hetero‐Diels–Alder (HDA) cycloaddition. A linear glycopolymer of similar size and composition was also synthesised in order to compare the protein binding characteristics of the polymer with glycodendritic endfunctionality to the linear glycol blockcopolymer. The two amphiphilic polymers were self‐assembled in water into micelles. These particles were then tested for their ability to bind to Concanavalin A (Con A). In a turbidity assay, the polymer glycodendron exhibited a significantly faster clustering rate to the lectin as compared to the linear glycopolymer. In a precipitation assay, it is found that significantly less glucose residue is required for binding per Con A for the polymer with the glycodendritic endfunctionality.

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One‐step Electro‐spinning/netting Technique for Controllably Preparing Polyurethane Nano‐fiber/net
Authors: Hu Juanping , Wang Xianfeng , Ding Bin , Lin Jinyou , Yu Jianyong , Sun Gang
Published: August 2011

Electro‐spinning/netting (ESN) as a cutting‐edge technique evokes much interest because of its ability in the one‐step preparation of versatile nano‐fiber/net (NFN) membranes. Here, a controllable fabrication of polyurethane (PU) NFN membranes with attractive structures, consisting of common electrospun nanofibers and two‐dimensional (2D) soap bubble‐like structured nano‐nets via an ESN process is reported. The unique nanoscaled NFN architecture can be finely controlled by regulating the solution properties and several ESN process parameters. The versatile PU nano‐nets comprising interlinked nanowires with ultrathin diameters (5–40 nm) mean that the NFN structured membranes possess several excellent characteristics, such as an extremely large specific surface area, high porosity and large stacking density, which would be particularly useful for applications in ultrafiltration, special protective clothing, ultrasensitive sensors, catalyst support and so on.

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New Thiol‐Responsive Mono‐Cleavable Block Copolymer Micelles Labeled with Single Disulfides
Authors: Khorsand Sourkohi Behnoush , Schmidt Rolf , Oh Jung Kwon
Published: August 2011

Thiol‐responsive symmetric triblock copolymers having single disulfide linkages in the middle blocks (called mono‐cleavable block copolymers, ss‐ABP2) were synthesized by atom transfer radical polymerization in the presence of a disulfide‐labeled difunctional Br‐initiator. These brush‐like triblock copolymers consist of a hydrophobic polyacrylate block having pendent oligo(propylene oxide) and a hydrophilic polymethacrylate block having pendent oligo(ethylene oxide). Gel permeation chromatography and 1H NMR results confirmed the synthesis of well‐defined mono‐cleavable block copolymers and revealed that polymerizations were well controlled. Because of amphiphilic nature, these copolymers self‐assembled to form colloidally stable micelles above critical micellar concentration of 0.032 mg · mL−1. In response to reductive reactions, disulfides in thiol‐responsive micelles were cleaved. Atomic force microscopy and dynamic light scattering analysis suggested that the cleavage of disulfides caused dissociation of micelles to smaller‐sized assembled structures in water. Moreover, in a biomedical perspective, the mono‐cleavable block copolymer micelles are not cytotoxic and thus biocompatible.

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Phase Behavior of Polymer‐Containing Systems: Recent Advances Through Computer Simulation
Authors: Binder Kurt , Müller M. , Vink R. L. C.
Published: August 2011

Computer simulations dealing with the phase transitions and phase diagrams of polymer solutions, polymer mixtures, and polymers in heterogeneous environments are still a methodological challenge, since nontrivial structure occurs from the Angstrom‐scale of covalent chemical bonds to the micrometer scale in the resulting multiphase materials. A brief review of strategies that were developed to deal with these problems will be given, and a few highlights of recent results from the research groups of the authors will be described.

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Accuracy of the cylinder approximation for susceptometric measurement of intravascular oxygen saturation
Authors: Li Cheng , Langham Michael C. , Epstein Charles L. , Magland Jeremy F. , Wu Jue , Gee James , Wehrli Felix W.
Published: August 2011

Susceptometry‐based MR oximetry has previously been shown suitable for quantifying hemoglobin oxygen saturation in large vessels for studying vascular reactivity and quantification of global cerebral metabolic rate of oxygen utilization. A key assumption underlying this method is that large vessels can be modeled as long paramagnetic cylinders. However, bifurcations, tapering, noncircular cross‐section, and curvature of these vessels produce substantial deviations from cylindrical geometry, which may lead to errors in hemoglobin oxygen saturation quantification. Here, the accuracy of the “long cylinder” approximation is evaluated via numerical computation of the induced magnetic field from 3D segmented renditions of three veins of interest (superior sagittal sinus, femoral and jugular vein). At a typical venous oxygen saturation of 65%, the absolute error in hemoglobin oxygen saturation estimated via a closed‐form cylinder approximation was 2.6% hemoglobin oxygen saturation averaged over three locations in the three veins studied and did not exceed 5% for vessel tilt angles <30° at any one location. In conclusion, the simulation results provide a significant level of confidence for the validity of the cylinder approximation underlying MR susceptometry‐based oximetry of large vessels. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Three‐dimensional MRI with independent slab excitation and encoding
Authors: Eissa Amir , Wilman Alan H.
Published: August 2011

Three‐dimensional MRI is typically performed with the same orientation for radiofrequency slab excitation and slab select phase encoding. We introduce independent slab excitation and encoding to create a new degree of freedom in three‐dimensional MRI, which is the angular relationship between the prescribed excitation volume and the voxel encoding grid. By separating the directions of slab excitation and slab phase encoding, the independent slab excitation and encoding method allows choice of optimal voxel orientation, while maintaining volume excitation based on anatomic landmarks. The method requires simple pulse sequence modifications and uses standard image reconstruction followed by removal of aliasing and image reformatting. The independent slab excitation and encoding method enables arbitrary oblique angle imaging using fixed voxel encoding gradients to maintain similar eddy current, concomitant field, or magnetic dipole effects independent of the oblique angle of excitation. We apply independent slab excitation and encoding to phase and susceptibility‐weighted imaging using fixed voxel encoding aligned with the main magnetic field to demonstrate its value in both standardizing and improving image contrast, when using arbitrary oblique imaging volumes. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Parallel traveling‐wave MRI: A feasibility study
Authors: Pang Yong , Vigneron Daniel B. , Zhang Xiaoliang
Published: August 2011

Traveling‐wave magnetic resonance imaging utilizes far fields of a single‐piece patch antenna in the magnet bore to generate radio frequency fields for imaging large‐size samples, such as the human body. In this work, the feasibility of applying the “traveling‐wave” technique to parallel imaging is studied using microstrip patch antenna arrays with both the numerical analysis and experimental tests. A specific patch array model is built and each array element is a microstrip patch antenna. Bench tests show that decoupling between two adjacent elements is better than ‐26‐dB while matching of each element reaches ‐36‐dB, demonstrating excellent isolation performance and impedance match capability. The sensitivity patterns are simulated and g‐factors are calculated for both unloaded and loaded cases. The results on B sensitivity patterns and g‐factors demonstrate the feasibility of the traveling‐wave parallel imaging. Simulations also suggest that different array configuration such as patch shape, position and orientation leads to different sensitivity patterns and g‐factor maps, which provides a way to manipulate B1 fields and improve the parallel imaging performance. The proposed method is also validated by using 7T MR imaging experiments. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Virtual dye angiography: Flow visualization for MRI‐guided interventions
Authors: George Ashvin K. , Faranesh Anthony Z. , Ratnayaka Kanishka , Derbyshire J. Andrew , Lederman Robert J. , Hansen Michael S.
Published: August 2011

In magnetic resonance imaging‐guided cardiovascular interventional procedures, it is valuable to be able to visualize blood flow immediately and interactively in selected regions. In particular, it is useful to assess normal or pathological communications between specific heart chambers and vessels. Phase‐contrast velocity mapping is not suitable for this purpose as it requires too much data and is not capable of determining directly if blood originating in one location travels to a nearby location. This article presents a novel flow visualization method called virtual dye angiography that enables visualization of blood flow analogous to selective catheter angiography. The method uses two‐dimensional radio frequency pulses to achieve interactive, intermittent, targeted saturation of a localized region of the blood pool. The flow of the saturated spins is observed directly on real‐time images or, in an enhanced manner, using ECG synchronized background subtraction. The modular nature of the technique allows for easy and seamless integration into a real‐time, interactive imaging system with minimal overhead. We present initial results in animals and in a healthy human volunteer. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Blipped‐controlled aliasing in parallel imaging for simultaneous multislice echo planar imaging with reduced g‐factor penalty
Authors: Setsompop Kawin , Gagoski Borjan A. , Polimeni Jonathan R. , Witzel Thomas , Wedeen Van J. , Wald Lawrence L.
Published: August 2011

Simultaneous multislice Echo Planar Imaging (EPI) acquisition using parallel imaging can decrease the acquisition time for diffusion imaging and allow full‐brain, high‐resolution functional MRI (fMRI) acquisitions at a reduced repetition time (TR). However, the unaliasing of simultaneously acquired, closely spaced slices can be difficult, leading to a high g‐factor penalty. We introduce a method to create interslice image shifts in the phase encoding direction to increase the distance between aliasing pixels. The shift between the slices is induced using sign‐ and amplitude‐modulated slice‐select gradient blips simultaneous with the EPI phase encoding blips. This achieves the desired shifts but avoids an undesired “tilted voxel” blurring artifact associated with previous methods. We validate the method in 3× slice‐accelerated spin‐echo and gradient‐echo EPI at 3 T and 7 T using 32‐channel radio frequency (RF) coil brain arrays. The Monte‐Carlo simulated average g‐factor penalty of the 3‐fold slice‐accelerated acquisition with interslice shifts is <1% at 3 T (compared with 32% without slice shift). Combining 3× slice acceleration with 2× inplane acceleration, the g‐factor penalty becomes 19% at 3 T and 10% at 7 T (compared with 41% and 23% without slice shift). We demonstrate the potential of the method for accelerating diffusion imaging by comparing the fiber orientation uncertainty, where the 3‐fold faster acquisition showed no noticeable degradation. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Improved initial value estimation for short echo time magnetic resonance spectroscopy spectral analysis using short T2 signal attenuation
Authors: Steinberg Jeffrey , Soher Brian J.
Published: August 2011

Robust spectral analysis of magnetic resonance spectroscopy data frequently uses a spectral model with prior metabolite signal information within a nonlinear least squares optimization algorithm. Starting values for the spectral model greatly influence the final results. Short echo time magnetic resonance spectroscopy contains broad signals that overlap with metabolite signals, complicating the estimation of starting values. We describe a method for more robust initial value estimation using a filter to attenuate short T2 signal contributions (e.g., macromolecules or residual lipids). The method attenuates signals by truncating early points in the data set. Metabolite peak estimation is simplified by the removal of broad, short T2 signals, and corrections for metabolite signal truncation are described. Short echo time simulated Monte Carlo data and in vivo data were used to validate the method. Areas for metabolite signals in the Monte Carlo data with singlet (N‐acetylaspartate, creatine, choline) and singlet‐like (myo‐inositol) resonances were estimated within 10% of actual value for various metabolite line widths, signal‐to‐noise ratios, and underlying broad signal contributions. Initial value estimates of in vivo magnetic resonance spectroscopy data were within 14% of metabolite area ratios relative to the creatine peak fitted using established magnetic resonance spectroscopy spectral analysis software. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Dynamics of unsaturated poroelastic solids at finite strain
Authors: Uzuoka Ryosuke , Borja Ronaldo I.
Published: August 2011

We derive the governing equations for the dynamic response of unsaturated poroelastic solids at finite strain. We obtain simplified governing equations from the complete coupled formulation by neglecting the material time derivative of the relative velocities and the advection terms of the pore fluids relative to the solid skeleton, leading to a so‐called us − pw − pa formulation. We impose the weak forms of the momentum and mass balance equations at the current configuration and implement the framework numerically using a mixed finite element formulation. We verify the proposed method through comparison with analytical solutions and experiments of quasi‐static processes. We use a neo‐Hookean hyperelastic constitutive model for the solid matrix and demonstrate, through numerical examples, the impact of large deformation on the dynamic response of unsaturated poroelastic solids under a variety of loading conditions. Copyright © 2011 John Wiley & Sons, Ltd.
Sodium relaxation times in the knee joint in vivo at 7T
Authors: Madelin Guillaume , Jerschow Alexej , Regatte Ravinder R.
Published: August 2011

The sodium concentration correlates directly with the concentration of proteoglycans (PG) in cartilage, the loss of which is an early signature of osteoarthritis (OA). As a result, quantitative sodium MRI is a promising technique for assessing the degradation of articular cartilage in patients with OA. Sodium relaxation times can also provide information on the degradation of cartilage: it has already been shown on bovine cartilage that T1 and T2long are longer and T2short shorter when the PG concentration decreases. In this study, sodium T1, and relaxation maps were measured in vivo at 7 T on 8 healthy volunteers and in 4 different regions of the cartilage in the knee joint. The patellar, femoro‐tibial medial, lateral, and femoral condyle cartilage have an average T1 ∼ 20 ms, but different (from 0.5 ms to 1.4 ms) and (from 11.4 ms to 14.8 ms). Statistically significant differences in T1, and were observed between the different regions in cartilage (p ≪ 10− 5). Statistical differences in T1 were also observed between male and female data (p ≪ 10− 5). These relaxation times measurements can further be applied as correction factors for sodium concentration maps in vivo and can also be useful as complementary information to quantitative sodium MRI in the quest for detecting early OA. These measurements were done on low resolution sodium images in order to acquire sufficient quality data for fitting (5 images for T1 and 9 images for ) while keeping the total time of acquisition of the data reasonable for the volunteer’s comfort (1 h 15 min). Copyright © 2011 John Wiley & Sons, Ltd.
Service Dogs and People with Physical Disabilities Partnerships: A Systematic Review
Authors: Winkle Melissa , Crowe Terry K. , Hendrix Ingrid
Published: August 2011

Occupational therapists have recognized the benefits that service dogs can provide people with disabilities. There are many anecdotal publications extolling the benefits of working with service dogs, but few rigorous studies exist to provide the evidence of the usefulness of this type of assistive technology option. This systematic review evaluates the published research that supports the use of service dogs for people with mobility‐related physical disabilities.

Articles were identified by computerized search of PubMed, CINAHL, PsycINFO, OT Seeker, the Cochrane Database of Systematic Reviews, SportDiscus, Education Research Complete, Public Administration Abstracts, Web of Knowledge and Academic Search Premier databases with no date range specified. The keywords used in the search included disabled persons, assistance dogs or service dogs and mobility impairments. The reference lists of the research papers were checked as was the personal citation database of the lead author. Twelve studies met the inclusion criteria and whereas the findings are promising, they are inconclusive and limited because of the level of evidence, which included one Level I, six Level III, four Level IV and one Level V. All of the studies reviewed had research design quality concerns including small participant sizes, poor descriptions of the interventions, outcome measures with minimal psychometrics and lack of power calculations. Findings indicated three major themes including social/participation, functional and psychological outcomes; all of which are areas in the occupational therapy scope of practice. Occupational therapists may play a critical role in referral, assessment, assisting clients and consulting with training organizations before, during and after the service dog placement process. In order for health care professionals to have confidence in recommending this type of assistive technology, the evidence to support such decisions must be strengthened. Copyright © 2011 John Wiley & Sons, Ltd.
Pitfalls in meta‐analyses on adverse events reported from clinical trials
Authors: Huang Han‐Yao , Andrews Elizabeth , Jones Judith , Skovron Mary Lou , Tilson Hugh
Published: August 2011

In recent years, comparative effectiveness research has been more aggressively pursued as a means to improve health care, including systematic reviews and meta‐analyses to inform health policy decision making. Because most clinical trials have pre‐specified approaches to collecting data on efficacy, the value of systematic reviews and meta‐analyses in assessing efficacy outcomes is generally accepted. In contrast, collection of data on adverse events is seldom well structured. Hence, the methodological considerations for comparing adverse events from such non‐aligned sources differ substantially from those for comparing efficacy endpoints.

We address several important pitfalls in performing systematic reviews and meta‐analyses on adverse events in clinical trials, and we offer recommendations for remedies. Some pitfalls arise from the fact that adverse events often are not the primary endpoints in clinical trials, hence incomplete reporting, inconsistent event definitions, various level of effort in reporting unexpected adverse events, and inappropriate use of statistical testing. Others are posed by certain important characteristics of adverse events data. The very concept of “adverse events” may skew the ascertainment, attribution, and reporting of the events. In addition, problems for meta‐analysis methods arise in situations involving zero or rare events and withdrawal or loss to follow‐up because of adverse events. We highlight recent initiatives that may improve the assessment and cross‐study summary of adverse events. We anticipate that future guidance for conducting systematic reviews and meta‐analyses will evolve to address the important methodological pitfalls we highlight here, and the practice of assessing the totality of evidence on drug safety will be improved. Copyright © 2011 John Wiley & Sons, Ltd.
An alternative method for spectral response measurements of large‐area thin‐film photovoltaic modules
Authors: Pravettoni Mauro , Komlan Anika , Galleano Roberto , Müllejans Harald , Dunlop Ewan D.
Published: August 2011

A new method for the spectral response measurement of large‐area single and multi‐junction thin‐film photovoltaic modules is presented, making use of a chopped monochromatic beam produced from a continuous source with band pass filters and lock‐in technique. The beam is projected onto part of the test module and superimposed over continuous bias light of variable colour. The procedure for the determination of the absolute spectral response is presented, and the influence of the intrinsic non‐uniformity of the monochromatic beam is investigated. The results obtained are compared with those from two other methods of spectral response measurement, providing a validation of the proposed experimental setup. Copyright © 2011 John Wiley & Sons, Ltd.
Coherent transmission in multiterminal molecular conductors
Authors: Malysheva Lyuba , Onipko Alexander
Published: August 2011

We consider coherent transport in an arbitrary molecular complex functioning as ${\cal N}$‐terminal conductor. The matrices that enter Datta's trace formula for the transmission function T(E) are represented in terms of free‐molecule Green's function matrix elements referring exclusively to molecular atoms perturbed by the lead–molecule interaction. Explicit expressions of transmission function are obtained for a commonly used model of multiterminal molecular devices, where the molecule is coupled with each lead via a single bond. In the particular cases of connection of molecular wires via a single atom and a benzene ring, this gives the analytical expressions of T(E). Physical implications of the derived formulas are briefly discussed.
Bibliometric analysis of fifty years of physica status solidi
Authors: Marx Werner , Hoffmann Dieter
Published: August 2011

Bibliometric methods are used to analyze quantitatively the journal physica status solidi (pss) 50 years after its inception. First, the coverage of the journal by the relevant citation indices accessible under the Web of Science (WoS) and the field‐specific INSPEC database is examined. The number of papers published per year by the journal as a whole and by the specific pss series is given. The time evolution of the pss output in terms of papers per year is compared with the output evolution of some major competing journals in the field of condensed‐matter physics. The top‐12 most frequently cited pss papers published within the complete time period 1961–2010 and within the two separate time periods 1974–1989 and 1990–2010 (before and after the German reunification) are listed. The citation time curves (citation history) of the three most frequently cited pss papers are presented. Furthermore, the Journal Impact Factors (JIFs) of the pss journal series (a) and (b) are discussed and their time evolution is shown. Moreover, the distribution of the pss papers over their document types and the authors is given. The countries of authors are ranked for the complete time period 1961–2010 as well as for the time periods 1973–1989 and 1990–2010. The complete ensemble of the citing papers of the pss papers is analyzed and discussed. The journals citing most often the pss papers published in the year 2000 are listed. Finally, the distribution of the pss papers over the various subject areas and classification terms based on the INSPEC database is tabled.
The Tensile Response and Fracture Behavior of Four High Strength Specialty Steels
Authors: Srivatsan T. S. , Manigandan K. , Quick Thomas
Published: August 2011

In this technical paper the role of alloy chemistry and secondary processing on tensile response and final fracture behavior of four high strength steels is presented and discussed. The conjoint influence of composition, secondary processing and intrinsic microstructural features in governing stress versus strain response and tensile properties is highlighted. The macroscopic mode and intrinsic microscopic features that result from final fracture of the four high strength steels is discussed. The intrinsic microscopic mechanisms governing tensile deformation and final fracture behavior of the high strength steels are outlined in light of the specific role played by composition, intrinsic microstructural effects and nature of loading.
Inclusion Characterization of Titanium Stabilized Ultra Low Carbon Steels: Impact of Oxygen Activity before Deoxidation
Authors: Lyons C. , Kaushik P.
Published: August 2011

At an ArcelorMittal steel‐producing plant, heats deoxidized with initial oxygen activity greater or equal to 750 ppm were automatically downgraded. After analyzing liquid steel samples using automated SEM and remelt button techniques, it was concluded that higher oxygen levels before killing do not necessarily correlate to an increase in inclusion content of the heats. Results from both automated scanning electron microscope (SEM) and remelt button technique showed that the frequency of inclusions decreases with increasing inclusion size regardless of oxygen levels. The cleanliness of the heats with temperature correction following deoxidation at the RH degasser was also determined. It was observed that the number density of inclusions significantly increased in the ladle samples and more than doubled in the tundish samples for the heats with late temperature correction at the degasser and, therefore, this practice should be controlled.
Gestational sac and embryonic growth are not useful as criteria to define miscarriage: a multicenter observational study
Authors: Abdallah Y. , Daemen A. , Guha S. , Syed S. , Naji O. , Pexsters A. , Kirk E. , Stalder C. , Gould D. , Ahmed S. , Bottomley C. , Timmerman D. , Bourne T.
Published: August 2011

Objectives

We studied changes in mean gestational sac diameter (MSD) and embryonic crown–rump length (CRL) in intrauterine pregnancies of uncertain viability (IPUVs). We aimed to establish cut‐off values for MSD and CRL growth that could be definitively associated with either viability or miscarriage, and to establish the relationship between growth in MSD and appearance of embryonic structures in the gestational sac.

Methods

One thousand and sixty consecutive IPUVs were recruited prospectively from four London University hospitals: 462 with no yolk sac or embryo, 419 with a yolk sac but no embryo, and 179 with an embryo but no heartbeat visible. IPUV was defined as an empty gestational sac with or without a yolk sac but no embryo seen with MSD < 20 or < 30 mm (depending on center) or an embryo with no heartbeat and CRL < 6 mm or < 8 mm (depending on center). Scans were repeated 7–14 days later. The endpoint was viability at first‐trimester screening ultrasonography between 11 and 14 weeks. Change in MSD and CRL between the first and second scans of each pregnancy was compared with respect to viability and appearance of embryonic structures using the two‐sample t‐test.

Results

The study included 359 pregnancies in which a gestational sac with or without embryo was identified at the follow‐up scan 7–14 days later. Of these, 192 were viable and 167 non‐viable at the 11–14‐week scan. MSD growth was significantly higher in viable than non‐viable pregnancies (mean 1.003 vs. 0.503 mm/day; P < 0.001, 95% CI of difference 0.403–0.596). A difference in CRL growth was found between the two groups (mean 0.673 vs. 0.148 mm/day; P < 0.001, 95% CI of difference 0.345–0.703). MSD growth of 0.6 mm/day was associated with a specificity for diagnosing miscarriage of 90.1%, a sensitivity of 61.7% and 19 false‐positive test results. A cut‐off of CRL growth rate of 0.2 mm/day gave a sensitivity of 76.3% and there were no false‐positive test results for miscarriage. On repeat scan the failure of either a yolk sac or embryo to be visualized was always associated with miscarriage.

Conclusion

There is an overlap in MSD growth rates between viable and non‐viable IPUV. No cut‐off exists for MSD growth below which a viable pregnancy could be safely excluded. A cut‐off value for CRL growth of 0.2 mm/day was always associated with miscarriage. These data suggest that criteria to diagnose miscarriage based on growth in MSD and CRL are potentially unsafe. However, finding an empty gestational sac on two scans more than 7 days apart is highly likely to indicate miscarriage, irrespective of growth. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Standardized approach for imaging and measuring Cesarean section scars using ultrasonography
Authors: Naji O. , Abdallah Y. , Bij De Vaate A. J. , Smith A. , Pexsters A. , Stalder C. , McIndoe A. , Ghaem‐Maghami S. , Lees C. , Brölmann H. A. M. , Huirne J. A. F. , Timmerman D. , Bourne T.
Published: August 2011

Incomplete healing of the scar is a recognized sequel of Cesarean section (CS) and may be associated with complications in later pregnancies. These complications can include scar pregnancy, a morbidly adherent placenta, scar dehiscence or rupture. To date there is uncertainty relating to the factors that lead to poor scar healing and how to recognize it. In recent years, there has been an increase in studies using ultrasound that describe scars as deficient, or poorly, incompletely or inadequately healed with few data to associate the morphology of the scar with the functional integrity of the lower segment of the uterus. There have been multiple attempts to describe CS scars using ultrasonography. Different terminology, methods and results have been reported, yet there is still no consensus regarding the prevalence, clinical significance or most appropriate method to describe the appearances of these scars. Developing a test that can predict the likelihood of women having problems associated with a CS scar is becoming increasingly important. On the other hand, understanding whether the ultrasound appearances of the scar can tell us anything about its integrity is not well supported by the research evidence. In this article we present an overview of ultrasound‐based definitions and methods used to describe CS scars. We also present information relating to the performance of alternative techniques used to evaluate CS scars. Having examined the current evidence we suggest a standardized approach to describe CS scars using ultrasound so that future studies can be meaningfully compared. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Adaptive dual‐radio spectrum‐sensing scheme in cognitive radio networks
Authors: Wang Weiwei , Cai Jun , Alfa Attahiru S. , Soong Anthony C.K. , Li Simin
Published: August 2011

In this paper, a novel spectrum‐sensing scheme, called adaptive dual‐radio spectrum‐sensing scheme (ADRSS), is proposed for cognitive radio networks. In ADRSS, each secondary user (SU) is equipped with a dual radio. During the data transmission, with the received signal‐to‐noise ratio of primary user (PU) signal, the SU transmitter (SUT) and the SU receiver (SUR) are selected adaptively to sense one channel by one radio while communicating with each other by the other one. The sensing results of the SUR are sent to the SUT through feedback channels (e.g., ACK). After that, with the sensing results from the SUT or the SUR, the SUT can decide whether the channel switching should be carried out. The theoretical analysis and simulation results indicate that the normalized channel efficiency, defined as the expected ratio of time duration without interference to PUs in data transmission to the whole frame length, can be improved while satisfying the interference constraint to PUs. After that, an enhanced ADRSS is designed by integrating ADRSS with cooperative spectrum sensing, and the performance of ADRSS under imperfect feedback channel is also discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Verifying compiled file system code
Authors: Mühlberg Jan Tobias , Lüttgen Gerald
Published: August 2011

This article presents a case study on retrospective verification of the Linux Virtual File System (VFS), which is aimed at checking violations of API usage rules and memory properties. Since VFS maintains dynamic data structures and is written in a mixture of C and inlined assembly, modern software model checkers cannot be applied. Our case study centres around our novel automated software verification tool, the SOCA Verifier, which symbolically executes and analyses compiled code. We describe how this verifier deals with complex features such as memory access, pointer aliasing and computed jumps in the VFS implementation, while reducing manual modelling to a minimum. Our results show that the SOCA Verifier is capable of analysing the complex Linux VFS implementation reliably and efficiently, thereby going beyond traditional testing tools and into niches that current software model checkers do not reach. This testifies to the SOCA Verifier’s suitability as an effective and efficient bug-finding tool during the development of operating system components.
Transabdominal Preperitoneal Repair for Obturator Hernia
Authors: Yokoyama Takahide , Kobayashi Akira , Kikuchi Toshiki , Hayashi Ken , Miyagawa Shinichi
Published: August 2011

Background

A laparoscopic surgical approach for obturator hernia (OH) repair is uncommon. The aim of the present study was to assess the effectiveness of laparoscopic transabdominal preperitoneal (TAPP) repair for OH.

Methods

From 2001 to May 2010, 659 patients with inguinal hernia underwent TAPP repair at in our institutes. Among these, the eight patients with OH were the subjects of this study.

Results

Three of the eight patients were diagnosed as having occult OH, and the other five were diagnosed preoperatively, by ultrasonography and/or computed tomography, as having strangulated OH. Bilateral OH was found in five patients (63%), and combined groin hernias, either unilaterally or bilaterally, were observed in seven patients (88%), all of whom had femoral hernia. Of the five patients with bowel obstruction at presentation, four were determined not to require resection after assessment of the intestinal viability by laparoscopy. There was one case of conversion to a two‐stage hernia repair performed to avoid mesh contamination: addition of mini‐laparotomy, followed by extraction of the gangrenous intestine for resection and anastomosis with simple peritoneal closure of the hernia defect in the first stage, and a Kugel hernia repair in the second stage. There was no incidence of postoperative morbidity, mortality, or recurrence.

Conclusions

Because TAPP allows assessment of not only the entire groin area bilaterally but also simultaneous assessment of the viability of the incarcerated intestine with a minimum abdominal wall defect, we believe that it is an adequate approach to the treatment of both occult and acutely incarcerated OH. Two‐stage hernia repair is technically feasible in patients requiring resection of the incarcerated intestine.
Small Wins Matter in Advocacy Movements: Giving Voice to Patients
Authors: Jason Leonard A.
Published: August 2011

In this article, the various players are delineated in a story of a contested illness and patient advocacy, played out within the corridors of federal power. It is suggested that the mistreatment and negative attitudes that health care providers and others have towards those with chronic fatigue syndrome (CFS) is possibly due to the social construction of this illness as being a “Yuppie flu” disease. Institutional factors are identified that created these norms and attributions, as well as the multiple stakeholders and constituent groups invested in exerting pressure on policy makers to effect systemic change. This article also provides examples of how the field of Community Psychology, which is fundamentally committed to/based on listening to and giving voice to patients, is broadly relevant to patient activism communities. This approach focused, over time, on epidemiological studies, the name, the case definition, and ultimately the change in CFS leadership at the Centers for Disease Control and Prevention. Keys to this “small wins” approach were coalition building, use of “oppositional experts” (professionals in the scientific community who support patient advocacy goals) to challenge federal research, and taking advantage of developing events/shifts in power. Ultimately, this approach can result in significant scientific and policy gains, and changes in medical and public perception of an illness.
The K-INDSCAL Model for Heterogeneous Three-Way Dissimilarity Data
Authors: Bocci Laura , Vichi Maurizio
Published: August 2011

A weighted Euclidean distance model for analyzing three-way dissimilarity data (stimuli by stimuli by subjects) for heterogeneous subjects is proposed. First, it is shown that INDSCAL may fail to identify a common space representative of the observed data structure in presence of heterogeneity. A new model that removes the rotational invariance of the classical multidimensional scaling problem and specifies K common homogeneous spaces is proposed. The model, called mixture INDSCAL in K classes, or briefly K-INDSCAL, still includes individual saliencies. However, the large number of parameters in K-INDSCAL may produce instability of the estimates and therefore a parsimonious model will also be discussed. The parameters of the model are estimated in a least-squares fitting context and an efficient coordinate descent algorithm is given. The usefulness of K-INDSCAL is demonstrated by both artificial and real data analyses.
Defining the Origins of the Iliofemoral, Ischiofemoral, and Pubofemoral Ligaments of the Hip Capsuloligamentous Complex Utilizing Computer Navigation
Authors: Nam Denis , Osbahr Daryl C. , Choi Daniel , Ranawat Anil S. , Kelly Bryan T. , Coleman Struan H.
Published: August 2011

Purpose

To use computer navigation software to investigate the specific origins of the hip capsuloligamentous complex.

Methods

Six fresh frozen cadaver hips were anatomically landmarked utilizing a three-dimensional computer navigation system. The acetabular origins of the iliofemoral, pubofemoral, and ischiofemoral ligaments were statically digitized. Computer software was used to create a 180° (6:00) meridian line positioned over the midpoint of the acetabular notch, and to present the results in a clocklike manner in hours and minutes (00:00) and also degrees relative to the 12 o'clock position.

Results

The iliofemoral ligament origin starts at 17° (±31°) from the 12 o'clock position, or 12:35 (±1:02) in hours and minutes, and ends at 69° (±13°) or 2:18 (±0:25), spanning a mean distance of 52° (±19°). The ischiofemoral ligament has the broadest origin, starting at 262° (±12°) or 8:44 (±0:24), and ending at 353° (±17°) or 11:45 (±0:14), spanning a mean distance of 90° (±6°). The pubofemoral ligament origin is the smallest, starting at 121° (±5°) or 4:02 (±0:11), and ending at 163° (±9°) or 5:27 (±0:18), spanning a mean distance of 42° (±5°). The iliofemoral ligament origin demonstrates the greatest anatomic variability with regards to its location and its size ( p = 0.002).

Conclusion

This study demonstrates that there is significant variability in the size and location of the iliofemoral ligament origin versus the pubofemoral and ischiofemoral ligaments.

Level of Evidence

Level IV anatomic cadaveric study. See the guidelines online for a complete description of level of evidence.