bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetic Data for the Transmetalation/Reductive Elimination in Palladium‐Catalyzed Suzuki–Miyaura Reactions: Unexpected Triple Role of Hydroxide Ions Used as Base
Authors: Amatore Christian , Jutand Anny , Le Duc Gaëtan
Published: January 2011

The mechanism of the reaction of trans‐[ArPdX(PPh3)2] (Ar=p‐Z‐C6H4; Z=CN, F, H; X=I, Br, Cl) with Ar′B(OH)2 (Ar′=p‐Z′‐C6H4; Z′=CN, H, OMe) has been established in DMF in the presence of the base OH− in the context of real palladium‐catalyzed Suzuki–Miyaura reactions. The formation of the cross‐coupling product ArAr′ and [Pd0(PPh3)3] has been followed through the application of electrochemical techniques. Kinetic data have been obtained for the first time, with determination of the observed rate constant, kobs, of the overall reaction. trans‐[ArPdX(PPh3)2] is not reactive in the absence of the base. The base OH− plays three roles. It favors the reaction: 1) by formation of trans‐[ArPd(OH)(PPh3)2], a key complex which, in contrast to trans‐[ArPdX(PPh3)2], reacts with Ar′B(OH)2 (rate‐determining transmetalation), and 2) by unexpected promotion of the reductive elimination from the intermediate trans‐[ArPdAr′(PPh3)2], which generates ArAr′ and a Pd0 species. Conversely, the base OH− disfavors the reaction by formation of the unreactive anionic Ar′B(OH)3−. As a consequence of these antagonistic effects of OH−, the overall reactivity is controlled by the concentration of OH− and passes through a maximum as the concentration of OH− is increased. Therefore, the base favors the rate‐determining transmetalation and unexpectedly also the reductive elimination.
Direct Determination of Bioavailable Molybdenum in Carbon Nanotubes
Authors: Giovanni Marcella , Ambrosi Adriano , Pumera Martin
Published: January 2011

Bioavailable residual metallic impurities within carbon nanotubes (CNTs) are responsible for the toxicity of CNTs. Herein we present a method for fast, sensitive determination of bioavailable molybdenum residual catalyst impurities within CNTs by using electrochemical oxidation in neutral pH buffers at low potentials. This method is unique because no other method can rapidly distinguish between bioavailable/mobilizable impurities from defects in CNTs and between the total amounts of impurities. This method will be indispensable for future toxicological studies of CNTs.
Sonochemical Degradation of Pharmaceutical Wastewater
Authors: Sivakumar Ramalingam , Muthukumar Karuppan
Published: January 2011

This study presents the influence of the addition of additives such as activated carbon, carbon tetra chloride, hydrogen peroxide, and potassium dichromate on ultrasonic reduction of pharmaceutical wastewater chemical oxygen demand (COD) under laboratory conditions. The addition of activated carbon increased the % COD reduction whereas the combined addition of activated carbon and H2O2/CCl4/K2Cr2O7 was found to show higher reduction. Among the various combinations investigated, the combined addition of activated carbon and CCl4 was found to be the best combination. However, the environmental and health problems associated with these chemicals limit the applicability of the process in an industrial level. Further investigation with this system showed that the initial pH and initial COD have significant influence on the removal rate. The data obtained were fitted with first order and Langmuir–Hinshelwood kinetic models. The values of the rate constants obtained indicated that the pharmaceutical wastewater can be treated efficiently by the proposed methods.
Plasma cells in systemic lupus erythematosus: The long and short of it all
Authors: Liu Zheng , Zou YongRui , Davidson Anne
Published: January 2011

Plasma cells can be classified as long‐ or short‐lived. The lifespan of a plasma cell largely depends on whether it arises from a germinal center or an extrafollicular locus and most importantly whether it can find a survival niche in the spleen or BM. In systemic lupus erythematosus (SLE) patients, long‐lived plasma cells are believed to be responsible for the production of anti‐RNA and anti‐cardiolipin antibodies, whereas short‐lived plasma cells, which are more susceptible to anti‐proliferation therapies, are the main producers of anti‐DNA antibodies. A previous study showed that transient overexpression of interferon‐α (IFN‐α), a cytokine that plays a pathogenic role in SLE, accelerates disease onset in lupus‐prone NZB/W mice. In this issue of the European Journal of Immunology, the same group report that IFN‐α induces large numbers of short‐lived plasma cells, accompanied by high titers of anti‐dsDNA antibodies in NZB/W, but not BALB/c, mice. Our commentary discusses this interesting observation in the context of the previous data regarding plasma cell differentiation and conveys our view about the clinical implications with respect to therapies that target plasma cells in SLE patients.
Bioelectronic Devices Controlled by Biocomputing Systems
Authors: Katz Evgeny
Published: January 2011

This paper outlines recent advances in the integration of enzyme‐based biocomputing systems operating as Boolean logic gates and their networks with various bioelectronic devices. “Smart” switchable electrodes for biosensors and biofuel cells with built‐in biomolecular logic were designed. Interfacing between the biocomputing systems and switchable electrodes resulted in bioelectronic devices controlled by complex patterns of variable biomolecular signals. Various biomedical applications of the novel logically‐controlled bioelectronic devices are feasible.
Image Printing on the Surface of Anti‐Biofouling Zwitterionic Polymer Brushes by Ion Beam Irradiation
Authors: Kitano Hiromi , Suzuki Hisatomo , Kondo Takuya , Sasaki Kenta , Iwanaga Shintaroh , Nakamura Makoto , Ohno Kohji , Saruwatari Yoshiyuki
Published: January 2011

A CMB monomer was polymerized on a glass plate with a surface‐confined ATRP initiator containing a 2‐bromoisobutyryl group. The glass plate modified with a PCMB brush was highly hydrophilic and showed a strong resistance against non‐specific adsorption of proteins and cell adhesion. Upon ion beam irradiation, furthermore, the PCMB brush was ablated and a hollow space with a designed shape could be made to which HEK293 cells (from human embryonic kidney) and Hep G2 (from human hepatoma) cells non‐specifically adhered, while no adhesion of these cells to the non‐treated area on the brush was observed. The present results clearly indicate the usefulness of ion beam‐printed patterns of anti‐biofouling zwitterionic polymer brushes in the biomedical field.

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Extrinsic eigenvalue estimates of Dirac operators on Riemannian manifolds
Authors: Huang Guangyue , Chen Li , Sun Xiaomei
Published: January 2011

For eigenvalues of generalized Dirac operators on compact Riemannian manifolds, we obtain a general inequality. By using this inequality, we study eigenvalues of generalized Dirac operators on compact submanifolds of Euclidean spaces, of spheres, and of real, complex and quaternionic projective spaces. We obtain explicit bounds for the (k + 1)‐th eigenvalue of generalized Dirac operators on such objects in terms of its first k eigenvalues, which depend on the mean curvature of the embedding and the curvature term in the Bochner‐Weitzenböck formula for the square of the Dirac operator. These inequalities of eigenvalues extend the recent results in 15. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Phase Evolution Theory for Polymer Blends with Extreme Chemical Dispersity: Parameterization of DDFT Simulations and Application to Poly(propylene) Impact Copolymers
Authors: Fraaije Johannes G. E. M. , Nath Shyamal K. , Remerie Klaas , Groenewold Jan
Published: January 2011

DDFT is applied to phase formation in homopolymer/copolymer blends in which the copolymer is extremely disperse with a uniform chemical composition distribution. Such systems develop a core/shell structure with a thick interface. This study is motivated by peculiarities in the phase evolution of industrial PP high‐impact copolymers. It is demonstrated that it is possible to reach time and length scales of relevance for realistic industrial blend systems. A rational method for improving the numerical efficiency of the calculations is presented. The model can be applied to a variety of industrially relevant systems with similar “random chemistry” or extreme copolymer dispersity in coatings, crude oil recovery systems, food emulsions, and so forth.

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General decompositions of multiattribute utility functions with partial utility independence
Authors: Abbas Ali E.
Published: January 2011

The construction of a multiattribute utility function is significantly simplified if it is possible to decompose the function into lower‐order utility assessments. When every attribute is utility independent of its complement, we have a powerful property that reduces the functional form into a multilinear combination of single‐attribute functions. We propose a natural extension to the multilinear form requiring the milder set of independence conditions: every attribute is utility independent of a subset of the attributes in its complement. We introduce a graph, which we call the bidirectional utility diagram, to facilitate the elicitation of these utility independence conditions. We also define a class of bidirectional diagrams, which we refer to as the canonical form. We show how this canonical representation leads to tractable functional forms of utility functions that may appeal to the decision analyst and can be used in practice. We also discuss situations where a canonical form does not exist. We then present an iterative approach to determine the lower‐order utility assessments that are required for a given set of utility independence assertions. We conclude with some extensions of this graph‐based approach to independence relations of the form: a subset of the attributes is utility independent of another subset. Copyright © 2010 John Wiley & Sons, Ltd.
Retinal ganglion cell death is induced by microglia derived pro‐inflammatory cytokines in the hypoxic neonatal retina
Authors: Sivakumar Viswanathan , Foulds Wallace S , Luu Chi D , Ling Eng‐Ang , Kaur Charanjit
Published: January 2011

Hypoxic injury, including that resulting in the retinopathy of prematurity, may induce retinal ganglion cell (RGC) death in the neonatal retina. We hypothesized that this may be mediated by excess production of tumour necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β) by microglia. One‐day‐old Wistar rats were subjected to hypoxia for 2 h and the expression of TNF‐α and IL‐1β and their receptors was determined in the retina. The mRNA and protein expression of TNF‐α, IL‐1β, TNF‐receptor 1 (TNF‐R1), and IL‐1 receptor 1 (IL‐1R1) and the tissue concentration of TNF‐α and IL‐1β were up‐regulated significantly after the hypoxic exposure. TNF‐α and IL‐1β immunoreactivity was localized in microglial cells, whereas that of TNF‐R1 and IL‐1R1 was restricted to RGCs, as confirmed by double immunofluorescence labelling. Along with this, increased expression of monocyte chemoattractant protein‐1 and its receptor CCR2 was detected in the microglia. Primary cultured microglia subjected to hypoxia showed enhanced release of TNF‐α and IL‐1β. Primary cultured retinal ganglion cells (RGCs) treated with conditioned medium derived from hypoxic microglia showed enhanced apoptosis, which was significantly reduced when the cells were treated with microglia conditioned medium neutralized with TNF‐α/IL‐1β antibody. Our results suggest that activated microglial cells in hypoxic neonatal retina produce increased amounts of TNF‐α and IL‐1β that could induce RGC death. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The 25th IWEPNM in Kirchberg – A look back to the past and prospects for the future
Authors: Kuzmany Hans , Thomsen Christian
Published: January 2011

For the 25th time, the Kirchberg Winterschool (IWEPNM 2011) provides a platform for reviewing and discussing new developments in the field of electronic properties of molecular nanostructures and their applications. The organizers use this occasion to look at the history, status, and future perspective of this high‐class scientific event.

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Imaging surfaces of nano‐scale roughness by atomic force microscopy with carbon nanotubes as tips: a comparative study
Authors: Munz Martin , Kim Jae‐Ho , Krause Oliver , Roy Debdulal
Published: January 2011

Accurate knowledge of the nanoroughness of surfaces is crucial for many applications related to optics, electronics or tribology. Although atomic force microscopy (AFM) can image surfaces with a nanometre spatial resolution, the finite size of standard tips means that pores, pits or grooves with dimensions similar to or smaller than the tip apex will not be accurately imaged. Furthermore, standard tips are made of silicon or silicon nitride and are prone to wear. Mitigation may arise from the availability of AFM tips with a carbon nanotube (CNT) at their foremost end. This study compares the imaging performance of ultrasharp Si tips, CNT AFM tips prepared by a Langmuir‐Blodgett (LB) technique, and of CNT AFM tips prepared by a chemical vapour deposition (CVD) technique. The free length of the CNT AFM tips is in the range 80–200 and 600–750 nm, respectively. A polycrystalline niobium film surface is imaged that shows nanoroughness. The measurements demonstrate that CNT AFM tips allow excellent imaging if the scan parameters are adjusted very carefully. Nevertheless, in some cases distortions are found. The measured average grain diameter is 19.9 ± 3.6 nm in the case of a CNT AFM tip made by the LB technique, and 18.0 ± 3.3 nm in the case of a CNT AFM tip made by CVD. In addition to cross‐sections of topography images, also the power spectral density (PSD) is analyzed. An empirical approach for the readout of the characteristic length is suggested that involves the first derivative of the decadic logarithm of the PSD. Copyright © 2011 John Wiley & Sons, Ltd.
Short‐term forecasting of surface layer wind speed using a continuous random cascade model
Authors: Baïle R. , Muzy J. F. , Poggi P.
Published: January 2011

This paper describes a statistical method for short‐term forecasting (1–12  h ahead) of surface layer wind speed using only recent observations, relying on the notion of continuous cascades. Inspired by recent empirical findings that suggest the existence of some cascading process in the mesoscale range, we consider that wind speed can be described by a seasonal component and a fluctuating part represented by a ‘multifractal noise’ associated with a random cascade. Performances of our model are tested on hourly wind speed series gathered at various locations in Corsica (France) and the Netherlands. The obtained results show that a better modeling of the noise term based on cascade process enhances the forecast; furthermore, there is a systematic improvement in the prediction as compared with reference models. Copyright © 2011 John Wiley & Sons, Ltd.
Shallow-water sloshing in vessels undergoing prescribed rigid-body motion in three dimensions
Authors: ARDAKANI HAMID ALEMI , BRIDGES THOMAS J.
Published: January 2011

New shallow-water equations (SWEs), for sloshing in three dimensions (two horizontal and one vertical) in a vessel which is undergoing rigid-body motion in 3-space, are derived. The rigid-body motion of the vessel (roll–pitch–yaw and/or surge–sway–heave) is modelled exactly and the only approximations are in the fluid motion. The flow is assumed to be inviscid but vortical, with approximations on the vertical velocity and acceleration at the surface. These equations improve previous shallow-water models. The model also extends to three dimensions the essence of the Penney–Price–Taylor theory for the highest standing wave. The surface SWEs are simulated using a split-step alternating direction implicit finite-difference scheme. Numerical experiments are reported, including comparisons with existing results in the literature, and simulations with vessels undergoing full 3-D rotations.
Gravity-induced collisions of spherical drops covered with compressible surfactant
Authors: ZINCHENKO ALEXANDER Z. , ROTHER MICHAEL A. , DAVIS ROBERT H.
Published: January 2011

Gravity-induced collisions of two spherical drops covered with an insoluble surfactant at low Reynolds numbers are considered. Unlike in previous collision studies, the present work accounts for nonlinear coupling between the surfactant distribution and drop hydrodynamics by solving the full unsteady convective–diffusion equation for the surfactant transport. Our method includes high-order three-dimensional multipole expansions for hydrodynamics and a Galerkin-type approach for the surfactant transport with implicit marching. The efficiency of the algorithm allows for calculating thousands of trajectories to very close contact and determining the collision efficiency (related to the critical initial horizontal offset) by trial and error. The solution is valid for arbitrary surface Péclet (Pes) and Marangoni (Ma) numbers and sets limitations on approximations used in prior work for collision-efficiency calculations. Two limiting cases are observed: at smallPesor largeMa, the variation in surfactant coverage is small, and the results for the incompressible surfactant model are recovered, while for largePesand smallMa, the collision efficiency approaches the clean-interface value. For moderate drop-size ratios (radius ratiok≤ 0.5), the results generally fall between these limits. At larger size ratios, however, the collision efficiency may even exceed the geometrical Smoluchowski limit for both drops and bubbles. Moreover, with even moderate redistribution of the surfactant, equal-sized drops can move relative to one another and collide. These novel effects do not exist for clean drops or drops covered with an incompressible surfactant, and they are due to the nonlinear coupling between surfactant dynamics and flow. This surfactant-enhanced coalescence takes place, for example, in a physical system of air bubbles in water if the surfactant surface concentration is dilute (Γ ≈ 1×10−9mol m−2, much smaller than the typical maximum-packing value of 10−5−10−6mol m−2).
An expression for droplet evaporation incorporating thermal effects
Authors: SEFIANE K. , BENNACER R.
Published: January 2011

We propose a general theoretical expression for sessile droplets' evaporation, incorporating thermal effects related to the thermal resistance of the substrate and liquid properties. We develop an expression which accounts for thermal effects associated with evaporative cooling; the latter leads to a reduction in the rate of evaporation, which is not accounted for in the current theories, i.e. ‘isothermal diffusion theories’. The threshold for transition to a regime in which thermal effects start to be significant is identified through a dimensionless number which includes substrate and liquid properties as well as the kinetics of evaporation. The proposed theory is validated against experimental data in a very wide range of conditions and for a variety of systems. The developed expression extends the domain of use of diffusion-based models for droplet evaporation and accurately describes some aspects of the phenomenon which, to the best of our knowledge, are highlighted for the first time.
Pollen flows within and between rice and millet fields in relation to farmer variety development in The Gambia
Authors: Nuijten Edwin , Richards Paul
Published: January 2011

In areas with less favourable conditions for agriculture, informal seed systems permit gene flow through pollen to play a crucial role in the development of new varieties. An important factor with great impact on cross-pollination is the plant breeding system, but so far this is little studied within the context of low-input farming systems. This research studied the chances of cross-pollination within and between rice fields in The Gambia. Size and time of flowering were measured for 28 rice fields in one village. The level of mixture was measured in 90 seed lots of rice collected from four villages. Based on the results, we suggest that in general cross-pollination between different rice genotypes occurs more often within fields than between fields. No clear relationship was found between the level of within-field mixture and socio-economic status of farmers. Some comparison was made with millet, which allowed the identification of various factors influencing pollen flow between different genotypes. Effective pollen flow (between genotypes) is a function of a number of factors, such as the rate of cross-pollination of a crop, number of off-types within fields, variety distinctiveness, farmer expert knowledge, length and reliability of the rainy season, growth duration of different varieties, availability of fields, pest pressure and number of varieties grown per field or per farmer. We hypothesize that a low cross-pollination rate is more favourable for the development of new varieties in farmer fields than a high cross-pollination rate.
Some characteristics of thin shear layers in homogeneous turbulent flow
Authors: Worth N. A. , Nickels T. B.
Published: January 2011

Tomographic particle image velocimetry measurements of homogeneous isotropic turbulence that have been made in a large mixing tank facility at Cambridge are analysed in order to characterize thin highly sheared regions that have been observed. The results indicate that such regions coincide with regions of high enstrophy, dissipation and stretching. Large velocity jumps are observed across the width of these regions. The thickness of the shear layers seems to scale with the Taylor microscale, as has been suggested previously. The results discussed here concentrate on examining individual realizations rather than statistics of these regions.
Jupiter's zonal winds: are they bands of homogenized potential vorticity organized as a monotonic staircase?
Authors: Marcus Philip S. , Shetty Sushil
Published: January 2011

The east–west striped pattern of clouds in Jupiter’s weather layer is accompanied by a zonal flow containing 12 eastward-going jet streams alternating in latitude with westward-going jet streams. Based on theory, simulation and observations of the Earth’s oceans and atmosphere, it is conjectured that Jupiter’s weather layer is made of bands of constant potential vorticity (PV), where the interfaces between bands are at the latitudes of the maxima of the eastward-going jet streams. It is speculated that the mixing of PV on Jupiter is analogous to the mixing of salt in the ocean by the Phillips effect, which causes the salt density to form a monotonic ‘staircase’. It is hypothesized that the PV in Jupiter’s weather layer is also a staircase, decreasing from north to south. PV is a function of vorticity, as well as parameters with unknown values, e.g. the vertical stratification and the zonal flow beneath the observable weather layer. Therefore, these hypotheses cannot be tested directly. Using an atmospheric model that contains these unknown parameters, we solved the inverse problem and found values of the unknown parameters (and their uncertainties) that best fit Jovian observations. The unknown parameters influence how the zonal flow interacts with large vortices, e.g. the Great Red Spot (GRS; the largest and longest-lived Jovian vortex, centred at 23°S) and the Oval BA (the second largest vortex, centred at 33°S). Although we found that the PV distribution is approximately piecewise-constant and that the peaks of the eastward-going jet streams are at the latitudes of PV interfaces, there is also a PV interface at 20°S, where there is a westward-going jet stream. We find that the zonal PV is not a monotonic staircase due to the ‘backwards’ interface at 20°S. We show that this backwards interface is necessary to make the GRS nearly round, and that without that interface, the Red Spot would be highly elongated in the east–west direction and probably unstable.
Characteristics of the turbulent/non-turbulent interface of a non-isothermal jet
Authors: Westerweel Jerry , Petracci Alberto , Delfos René , Hunt Julian C. R.
Published: January 2011

The turbulent/non-turbulent interface of a jet is characterized by sharp jumps (‘discontinuities’) in the conditional flow statistics relative to the interface. Experiments were carried out to measure the conditional flow statistics for a non-isothermal jet, i.e. a cooled jet. These experiments are complementary to previous experiments on an isothermalRe=2000 jet, where, in the present experiments on a non-isothermal jet, the thermal diffusivity is intermediate to the diffusivity of momentum and the diffusivity of mass. The experimental method is a combined laser-induced fluorescence/particle image velocimetry method, where a temperature-sensitive fluorescent dye (rhodamine 6G) is used to measure the instantaneous temperature fluctuations. The results show that the cooled jet can be considered to behave like a self-similar jet without any significant buoyancy effects. The detection of the interface is based on the instantaneous temperature, and provides a reliable means to detect the interface. Conditional flow statistics reveal the superlayer jump in the conditional vorticity and in the temperature.
Interfaces and inhomogeneous turbulence
Authors: Hunt J. C. R. , Eames I. , da Silva C. B. , Westerweel J.
Published: January 2011

A Euromech colloquium, on interfacial processes and inhomogeneous turbulence, was held in London on 28–30 June 2010. Papers were presented describing and analysing the influence of interfaces that separate turbulent/non-turbulent regions, between regions of contrasting fluid properties, or at the edge of boundaries. This paper describes a summary of the work presented, giving a snapshot of the current progress in this area, along with discussions about future research directions.
New developments in understanding interfacial processes in turbulent flows
Authors: Eames I. , Flor J. B.
Published: January 2011

Interfaces, across which fluid and flow properties change significantly, are a ubiquitous feature of most turbulent flows and are present within jets, plumes, homogeneous turbulence, oceans and planetary atmospheres. Even when the interfaces occupy a small volume fraction of the entire flow, they largely control processes such as entrainment and dissipation and can act as barriers to transport. This Theme Issue brings together some of the leading recent developments on interfaces in turbulence, drawing in many methodologies, such as experiments, direct number simulations, inverse methods and analytical modelling.
Spatial constancy mechanisms in motor control
Authors: Medendorp W. Pieter
Published: January 2011

The success of the human species in interacting with the environment depends on the ability to maintain spatial stability despite the continuous changes in sensory and motor inputs owing to movements of eyes, head and body. In this paper, I will review recent advances in the understanding of how the brain deals with the dynamic flow of sensory and motor information in order to maintain spatial constancy of movement goals. The first part summarizes studies in the saccadic system, showing that spatial constancy is governed by a dynamic feed-forward process, by gaze-centred remapping of target representations in anticipation of and across eye movements. The subsequent sections relate to other oculomotor behaviour, such as eye–head gaze shifts, smooth pursuit and vergence eye movements, and their implications for feed-forward mechanisms for spatial constancy. Work that studied the geometric complexities in spatial constancy and saccadic guidance across head and body movements, distinguishing between self-generated and passively induced motion, indicates that both feed-forward and sensory feedback processing play a role in spatial updating of movement goals. The paper ends with a discussion of the behavioural mechanisms of spatial constancy for arm motor control and their physiological implications for the brain. Taken together, the emerging picture is that the brain computes an evolving representation of three-dimensional action space, whose internal metric is updated in a nonlinear way, by optimally integrating noisy and ambiguous afferent and efferent signals.
Cortical mechanisms for trans-saccadic memory and integration of multiple object features
Authors: Prime Steven L. , Vesia Michael , Crawford J. Douglas
Published: January 2011

Constructing an internal representation of the world from successive visual fixations, i.e. separated by saccadic eye movements, is known as trans-saccadic perception. Research on trans-saccadic perception (TSP) has been traditionally aimed at resolving the problems of memory capacity and visual integration across saccades. In this paper, we review this literature on TSP with a focus on research showing that egocentric measures of the saccadic eye movement can be used to integrate simple object features across saccades, and that the memory capacity for items retained across saccades, like visual working memory, is restricted to about three to four items. We also review recent transcranial magnetic stimulation experiments which suggest that the right parietal eye field and frontal eye fields play a key functional role in spatial updating of objects in TSP. We conclude by speculating on possible cortical mechanisms for governing egocentric spatial updating of multiple objects in TSP.
Vision and the representation of the surroundings in spatial memory
Authors: Tatler Benjamin W. , Land Michael F.
Published: January 2011

One of the paradoxes of vision is that the world as it appears to us and the image on the retina at any moment are not much like each other. The visual world seems to be extensive and continuous across time. However, the manner in which we sample the visual environment is neither extensive nor continuous. How does the brain reconcile these differences? Here, we consider existing evidence from both static and dynamic viewing paradigms together with the logical requirements of any representational scheme that would be able to support active behaviour. While static scene viewing paradigms favour extensive, but perhaps abstracted, memory representations, dynamic settings suggest sparser and task-selective representation. We suggest that in dynamic settings where movement within extended environments is required to complete a task, the combination of visual input, egocentric and allocentric representations work together to allow efficient behaviour. The egocentric model serves as a coding scheme in which actions can be planned, but also offers a potential means of providing the perceptual stability that we experience.
Visual stability
Authors: Melcher David
Published: January 2011

Our vision remains stable even though the movements of our eyes, head and bodies create a motion pattern on the retina. One of the most important, yet basic, feats of the visual system is to correctly determine whether this retinal motion is owing to real movement in the world or rather our own self-movement. This problem has occupied many great thinkers, such as Descartes and Helmholtz, at least since the time of Alhazen. This theme issue brings together leading researchers from animal neurophysiology, clinical neurology, psychophysics and cognitive neuroscience to summarize the state of the art in the study of visual stability. Recently, there has been significant progress in understanding the limits of visual stability in humans and in identifying many of the brain circuits involved in maintaining a stable percept of the world. Clinical studies and new experimental methods, such as transcranial magnetic stimulation, now make it possible to test the causal role of different brain regions in creating visual stability and also allow us to measure the consequences when the mechanisms of visual stability break down.
Solanaceae XIPs are plasma membrane aquaporins that facilitate the transport of many uncharged substrates
Authors: Bienert Gerd Patrick , Bienert Manuela Désirée , Jahn Thomas Paul , Boutry Marc , Chaumont François
Published: January 2011

Major intrinsic proteins (MIPs) transport water and uncharged solutes across membranes in all kingdoms of life. Recently, an uncharacterized MIP subfamily was identified in the genomes of plants and fungi and named X Intrinsic Proteins (XIPs). Here, we describe the genetic features, localization, expression, and functions of a group of Solanaceae XIPs. XIP cDNA and gDNA were cloned from tobacco, potato, tomato, and morning glory. A conserved sequence motif in the first intron of Solanaceae XIPs initiates an RNA‐processing mechanism that results in two splice variants (α and β). When transiently or stably expressed in tobacco plants, yellow fluorescent protein‐tagged NtXIP1;1α and NtXIP1;1β were both localized in the plasma membrane. Transgenic tobacco lines expressing NtXIP1;1‐promoter‐GUS constructs and RT‐PCR studies showed that NtXIP1;1 was expressed in all organs. The NtXIP1;1 promoter was mainly active in cell layers facing the environment in all above‐ground tissues. Heterologous expression of Solanaceae XIPs in Xenopus laevis oocytes and various Saccharomyces cerevisiae mutants demonstrated that these isoforms facilitate the transport of bulky solutes, such as glycerol, urea, and boric acid. In contrast, permeability for water was undetectable. These data suggest that XIPs function in the transport of uncharged solutes across the cell plasma membrane in specific plant tissues, including at the interface between the environment and external cell layers.
Building bridges: formin1 of Arabidopsis forms a connection between the cell wall and the actin cytoskeleton
Authors: Martinière Alexandre , Gayral Philippe , Hawes Chris , Runions John
Published: January 2011

Actin microfilament (MF) organization and remodelling is critical to cell function. The formin family of actin binding proteins are involved in nucleating MFs in Arabidopsis thaliana. They all contain formin homology domains in the intracellular, C‐terminal half of the protein that interacts with MFs. Formins in class I are usually targeted to the plasma membrane and this is true of Formin1 (AtFH1) of A. thaliana. In this study, we have investigated the extracellular domain of AtFH1 and we demonstrate that AtFH1 forms a bridge from the actin cytoskeleton, across the plasma membrane and is anchored within the cell wall. AtFH1 has a large, extracellular domain that is maintained by purifying selection and that contains four conserved regions, one of which is responsible for immobilising the protein. Protein anchoring within the cell wall is reduced in constructs that express truncations of the extracellular domain and in experiments in protoplasts without primary cell walls. The 18 amino acid proline‐rich extracellular domain that is responsible for AtFH1 anchoring has homology with cell‐wall extensins. We also have shown that anchoring of AtFH1 in the cell wall promotes actin bundling within the cell and that overexpression of AtFH1 has an inhibitory effect on organelle actin‐dependant dynamics. Thus, the AtFH1 bridge provides stable anchor points for the actin cytoskeleton and is probably a crucial component of the signalling response and actin‐remodelling mechanisms.
A 5‐year venom immunotherapy protocol with 50 μg maintenance dose: safety and efficacy in school children
Authors: Konstantinou George N. , Manoussakis Emmanuel , Douladiris Nikolaos , Hatziioannou Anastasios , Giavi Stavroula , Saxoni‐Papageorgiou Photini , Papadopoulos Nikolaos G.
Published: January 2011

To cite this article: Konstantinou GN, Manoussakis E, Douladiris N, Hatziioannou A, Giavi S, Saxoni‐Papageorgiou P, Papadopoulos NG. A 5‐yr venom immunotherapy protocol with 50 μg maintenance dose: safety and efficacy in school children. Pediatric Allergy Immunology 2011; 22: 393–397.

Background:  Venom immunotherapy (VIT) has been shown to be an effective and safe treatment for preventing sting‐induced anaphylaxis in patients with systemic reactions to hymenoptera stings. A remaining problem is the relative effectiveness and safety of different immunotherapy protocols used with respect to maintenance dose, injection interval, and duration.

Objective:  We aimed to describe a modified cluster VIT protocol with a maintenance dose of 50 μg lasting 5 yr and to evaluate retrospectively its safety and efficacy in children.

Patients and Methods:  Fifty four children 9.5 ± 3.2 yr old with a history of at least one anaphylactic reaction to hymenoptera stings underwent VIT between 1995 and 2006. The identification of the offending insect(s) was based on patient’s report and documented with in‐vivo (SPTs and IDs) and in‐vitro (RAST/CAP) test results. A modified cluster outpatient protocol lasting 5 wks, reaching a maintenance dose of 50 μg was followed according to clinical history and test results. After the maintenance dose was achieved, the followed injection‐intervals were 4 wks for the first year, 5 wks for the 2nd year and 3rd year, and 6 wks for the last 2 yr.

Results:  Of the 54 children, 52 tolerated the 50 μg VIT protocol without side effects. Twenty one of them reported at least one field sting from at least one of the culprit, for their allergy, insects, 6 ± 3.5 yr after they have started VIT treatment. In 11 of them, sting occurred 3.5 ± 2.9 yr after the VIT was completed, whereas the other 10 of them during immunotherapy, 3.2 ± 1.4 yr after they have started VIT. In the remaining two children, the maintenance dose was increased to 100 μg due to systemic reactions from the VIT. The data reflect outcomes 6–16 yr after the patients’ initial allergic reaction.

Conclusion:  VIT with 50 μg maintenance dose lasting 5 yr appears to be safe and effective enough to induce tolerance in children with hymenoptera venom hypersensitivity.
Liver transplantation as a treatment option for three siblings with homozygous familial hypercholesterolemia
Authors: Tevfik Küçükkartallar , Yucel Yankol , Turan Kanmaz , Serdar Topaloğlu , Koray Acarli , Munci Kalayoglu
Published: January 2011

Küçükkartallar T, Yankol Y, Kanmaz T, Topaloğlu S, Acarli K, Kalayoglu M. Liver transplantation as a treatment option for three siblings with homozygous familial hypercholesterolemia. Pediatr Transplantation 2011: 15: 281–284. © 2011 John Wiley & Sons A/S.

Abstract:  FH is a hereditary inherited disorder of cholesterol metabolism. Homozygous form of the disease associates severe form of atherosclerotic disease. Clinicians have been tried to inhibit the progression of the homozygous FH with medical and surgical treatment. We here present three siblings with homozygous FH who were successfully treated with liver transplantation.
Analyses of inheritance patterns and consistent expression of sporamin and chitinase PjChi‐1 genes in Brassica napus
Authors: Liu HongBo , Naeem Muhammad S. , Liu Dan , Zhu YaNa , Guo Xiang , Cui Peng , Zhou WeiJun
Published: January 2011

With 6 figures and 2 tables

Stable and consistent expression of foreign genes in serial propagation is a crucial factor to induce effective and efficient resistance through genetic engineering in insects and fungi. To better understand the inheritance patterns and expression of transgenes, two genes (sporamin and chitinase PjChi‐1) in T1 progeny of four single‐copy T0 transformants were characterized. PCR detection revealed that the segregation ratio was 3 : 1 for tested plants of each T0 transformant, which agreed with the Mendelian rules. In RT‐PCR analysis, 10 positive progeny plants of T0‐11 line showed a stable expression of sporamin and PjChi‐1 but not in wild type. Moreover, a higher expression level of sporamin gene in T1‐11‐3 was confirmed compared to the other progeny plants using Northern blot hybridization technique. Artificial inoculation of 10 plants (T1‐11) with Lepidoptera larvae (Plutella xylostella) and fungus (Sclerotinia sclerotiorum) in in vitro bioassays showed significant resistance compared to the wild type. Progeny T1‐11‐3 showed the stronger resistance, which was consistent with the higher expression level of sporamin gene in Northern blot hybridization detection, whereas there was no difference in insect and fungi resistance among these positive T1‐11 plants. These results indicate that both combined genes have been inherited from parental transformants to their progeny and showed a consistent resistance to insect and fungus in all positive T1 progeny.
Governance approval for multisite, non‐interventional research: what can Harmonisation of Multi‐Centre Ethical Review learn from the New South Wales experience?
Authors: Vajdic C. M. , Meagher N. S. , Hicks S. C. , Faedo M. , Ward R. L. , Pearson S.‐A.
Published: January 2011

Background:  In 2007, New South Wales Health mandated the separation of ethical and scientific review from research governance at all New South Wales public health sites based on their distinction in the National Health and Medical Research Council National Statement. This separation allowed for single‐site ethical review of multicentre studies.

Aims:  To investigate the time taken for governance approval of multicentre studies through the site‐specific approval (SSA) process.

Methods:  A retrospective audit of the SSA process for five non‐interventional studies proposed by a university cancer research unit.

Results:  The median total governance approval time for all submissions (n= 28) was 12 weeks (range 2.5–64); median time from starting the SSA to submission was 8 weeks (range 1–48) and median time for governance approval was 5 weeks (range 0.3–40). Approval times were shorter for public compared to private institutions. Reasons for delays in finalising submissions for approval were the absence of institutional governance officers, lack of clarity regarding signatories, the need to identify a principal investigator employed by the institution, and lack of recognition of ethical approval by private institutions. The need to develop legal agreements between the university and hospital was the main reason for lengthy delays in obtaining approval.

Conclusions:  The advantages of a harmonised single ethical review process were undermined by the coexistence of a fragmented, complex and lengthy governance approval process. This experience has implications for the success of the national Harmonisation of Multi‐Centre Ethical Review (HoMER) model. A harmonised and fully supported national approach to research governance should be developed contemporaneously with HoMER.
Assessment of chronic hepatitis B: the importance of hepatitis B virus DNA testing
Authors: Croagh C. M. N. , Bell S. J. , Locarnini S. , Desmond P. V.
Published: January 2011

Background:  Chronic hepatitis B (CHB) has an estimated prevalence of 90 000 to 160 000 in Australia. Cirrhosis and hepatocellular carcinoma are important complications of CHB and appropriate evaluation of hepatitis B surface antigen (HBsAg)‐positive individuals is vital to identify treatment candidates.

Methods:  A review of the database of a tertiary hospital was performed and 348 HBsAg‐positive individuals with baseline demographic, virological, serological and biochemical variables were identified and evaluated cross‐sectionally. A small subgroup of hepatitis B e antigen (HBeAg)‐negative patients with normal alanine aminotransferase (ALT) at baseline were identified and followed longitudinally.

Results:  175/348 (50%) of patients were in the HBeAg‐negative, chronic hepatitis phase of disease, 22% in the HBeAg‐positive immune clearance and 6% in the immune tolerant phases. HBeAg‐negative patients were older and more likely to be male than HBeAg‐positive patients. The correlation between hepatitis B virus (HBV) DNA and ALT levels was examined. ALT and HBV DNA levels showed no correlation in HBeAg‐positive CHB and only a weak correlation in HBeAg‐negative patients. Furthermore, 35% of HBeAg‐negative patients with detectable HBV DNA had a normal ALT. Conversely 38% of HBeAg‐negative patients with no detectable HBV DNA had an elevated ALT. A persistently normal ALT over 24 months was seen in five of nine HBeAg‐negative patients with normal initial ALT and detectable HBV DNA.

Conclusion:  Appropriate evaluation of HBeAg‐negative CHB must include HBV DNA because the ALT is not a reliable guide to underlying viral replication.
Profiling the “Pro‐Environmental Individual”: A Personality Perspective
Authors: Markowitz Ezra M. , Goldberg Lewis R. , Ashton Michael C. , Lee Kibeom
Published: January 2011

There is considerable scientific interest in the psychological correlates of pro‐environmental behaviors. Much research has focused on demographic and social‐psychological characteristics of individuals who consistently perform such actions. Here, we report the results of 2 studies in which we explored relations between broad personality traits and pro‐environmental actions. Using a wide variety of behavior and personality measures, we consistently found moderate positive relations between Openness to Experience and pro‐environmental activities in both a community sample (Study 1: N = 778) and an undergraduate student sample (Study 2: N = 115). In Study 2, we showed that the effect of Openness on pro‐environmental behaviors was fully mediated by individuals’ environmental attitudes and connection to nature. Our findings suggest that high levels of aesthetic appreciation, creativity, and inquisitiveness, but not personality traits associated with altruism, may have motivated the performance of pro‐environmental actions among our respondents. Implications for intervention development are discussed.
EXPERTISE, WISDOM AND MORAL PHILOSOPHERS: A RESPONSE TO GESANG
Authors: COWLEY CHRISTOPHER
Published: January 2011

In a recent issue of Bioethics, Bernard Gesang asks whether a moral philosopher possesses greater moral expertise than a non‐philosopher, and his answer is a qualified yes, based not so much on his infallible access to the truth, but on the quality of his theoretically‐informed moral justifications. I reject Gesang's claim that there is such a thing as moral expertise, although the moral philosopher may well make a valid contribution to the ethics committee as a concerned and educated citizen. I suggest that wisdom is a lot more interesting to examine than moral expertise. Again, however, moral philosophers have no monopoly on wisdom, and the study of philosophy may even impede its cultivation.
Educating with the hands: working on the body/self in Alexander Technique
Authors: Tarr Jennifer
Published: January 2011

Traditionally, forms of body work such as Alexander Technique have been excluded from mainstream biomedicine and healthcare, despite attempts by practitioners to have the work accepted within the medical community. Using data from a UK‐based study of Alexander Technique which combined participant observation, interviews with 17 teachers and pupils, and analysis of historical texts, this article examines the relationship of the Alexander Technique to the field of healthcare, looking at its embodied practices, and contrasting these with the discourses in which it is framed. Applying Foucault’s concept of ‘techniques of the self’, the article examines Alexander Technique’s physical practices as a form of embodied knowledge, and goes on to look at its use of particular ideas about nature and evolution as guiding authorities, its emphasis on holism through its conception of the ‘self’, and how it has been positioned in relation to biomedical approaches. The article argues that while the embodied practice of Alexander Technique has much to offer to mainstream healthcare, the discourses and knowledge systems in which it is embedded make it unlikely to receive mainstream medical acceptance.