bluuebunny/crossref_metadata_2025 huggingface dataset:
Charge-sensitive infrared phototransistors: Characterization by an all-cryogenic spectrometer
Authors: Ueda Takeji , An Zhenghua , Hirakawa Kazuhiko , Komiyama Susumu
Published: May 2008

Charge-sensitive infrared phototransistors (CSIPs) with a 16×4 μm2 active area, which are fabricated in a GaAs/AlGaAs double-quantum-well structure, are studied with an all-cryogenic spectrometer operated at 4.2 K. Extremely low level of background radiation makes reliable determination of detector characteristics at 4.2 K possible: The detection band is found to be centered at the wavelength λ=14.7 μm with a bandwidth (full width at maximum) Δλ=1 μm. The quantum efficiency (η), the current responsivity (R), the noise equivalent power (NEP), and the specific detectivity (D∗) are derived to be η=(2±0.5)%, R=4×104–4×106 A/W, NEP≅6.8×10−19 W/Hz1/2, and D∗≅1.2×1015 cm Hz1/2/W. The dynamic range of detection is demonstrated to exceed 106 (approximately attowatts to picowatts), but the upper limit of the radiation power is limited by the radiation source intensity. The intrinsic dynamic range of the detector is suggested to reach 1013 (approximately attowatts to microwatts). The detection speed is suggested to be around 3 ns (300 MHz). The sensitivity of CSIPS is so high that single-photon signals are discerned in the photocurrent as stepwise increases in given amplitude. The value of D∗ is by a few orders of magnitude higher than that of the state-of-the-art multi-quantum-well infrared photodetectors. The extremely high sensitivity will open up the possibility of developing ultrahigh-speed imaging and/or ultrahigh-resolution passive microscopy system in the long wavelength infrared region.
Strain effects and thickness dependence of ferroelectric properties in epitaxial BiFeO3 thin films
Authors: Ma Hua , Chen Lang , Wang Junling , Ma J. , Boey F.
Published: May 2008

A “misfit strain-temperature” phase diagram for BiFeO3 thin film was constructed based on the Landau–Devonshire theory with the mechanical substrate effect. It is found that the polarization instabilities result in the formation of the monoclinic phases in BiFeO3 thin films. The effective substrate lattice parameter has been introduced to calculate the film thickness dependence of the polarization and the dielectric constants. The theoretical results are in agreement with the experimental data for the thickness dependence of ferroelectric properties of the BiFeO3 epitaxial thin films on SrTiO3 and Si substrates.
Saturation of intersubband transitions in p-doped GaAs∕AlGaAs quantum wells
Authors: Steed Robert , Matthews Mary , Plumridge Jonathan , Frogley Mark , Phillips Chris , Ikonic Zoran , Harrison Paul , Malis Oana , Pfeiffer Loren N. , West Kenneth W.
Published: May 2008

Optical saturation experiments have been performed on hh1-hh2 intersubband transitions in two samples of p-doped GaAs∕AlGaAs quantum wells. The transitions had energies of 183 and 160meV and the measured population relaxation times were 2±1.5 and 0.3±0.1ps, respectively. Modeling of the quantum wells with a 6×6 k⋅p method shows that intersubband scattering by LO phonons can account for these relaxation times. The valence bandstructure is typically more complicated than the conduction bandstructure in a quantum well but these measurements show that LO phonons are the dominant intersubband scattering mechanism in both cases.
Mid-IR focal plane array based on type-II InAs∕GaSb strain layer superlattice detector with nBn design
Authors: Kim H. S. , Plis E. , Rodriguez J. B. , Bishop G. D. , Sharma Y. D. , Dawson L. R. , Krishna S. , Bundas J. , Cook R. , Burrows D. , Dennis R. , Patnaude K. , Reisinger A. , Sundaram M.
Published: May 2008

A midwave infrared camera (λc=4.2μm) with a 320×256 focal plane array (FPA) based on type-II InAs∕GaSb strain layer superlattice (SLs) has been demonstrated. The detectors consist of an nBn heterostructure, wherein the SL absorber and contact layers are separated by a Al0.2Ga0.8Sb barrier layer, which is designed to have a minimum valence band offset. Unlike a PN junction, the size of the device is not defined by a mesa etch but confined by the lateral diffusion length of minority carriers. At 77K, the FPA demonstrates a temporal noise equivalent temperature difference (NETD) of 23.8mK (Tint=16.3ms and Vb=0.7V) with a peak quantum efficiency and detectivity at 3.8μm equal to 52% and 6.7×1011 Jones, respectively.
Photoelectric response of Schottky barrier in La0.7Ca0.3MnO3∕Nb:SrTiO3 heterojunctions
Authors: Luo Z. , Gao J. , Djurišić A. B. , Yip C. T. , Zhang G. B.
Published: May 2008

Heterojunctions composed of La0.7Ca0.3MnO3 and 0.05wt% Nb-doped SrTiO3 were fabricated using pulse laser deposition. The current-voltage characteristics of such heterojunctions can be described by tunneling with an effective Schottky barrier. These junctions showed significant response to ultraviolet and visible light. Band-to-band and internal photoemission were characterized by photoelectric experiments. A quantum efficiency of about 86% was observed at an incident energy of ∼3.95eV, which corresponds to the band-to-band excitation of electrons in Nb:SrTiO3. From the internal photoemission, the height of Schottky barrier was determined as 1.64eV.
Magnetic coupling between rare-earth and iron atoms in the La1−xRxFe11.5Si1.5 (R=Ce, Pr, and Nd) intermetallics
Authors: Jia L. , Sun J. R. , Shen J. , Dong Q. Y. , Hu F. X. , Zhao T. Y. , Shen B. G.
Published: May 2008

A systematic investigation on the effect of R doping, particularly the magnetic coupling between R and Fe, has been performed for the La1−xRxFe11.5Si1.5 intermetallics (R=Ce, Pr, and Nd). A magnetic interaction comparable to that between Fe atoms is found between the R and Fe atoms, which causes an enhancement of the Curie temperature up to ∼11% when ∼30% of the La atoms are replaced by R. The R–Fe coupling is further found to be strongly dependent of the species of the rare earths. It monotonically grows as R sweeps from Ce to Nd. This could be a consequence of the lanthanide contraction, which causes an enhancement of the intra-atomic magnetic coupling.
A soluble activin Type IIA receptor induces bone formation and improves skeletal integrity
Authors: Pearsall R. Scott , Canalis Ernesto , Cornwall-Brady Milton , Underwood Kathryn W. , Haigis Brendan , Ucran Jeffrey , Kumar Ravindra , Pobre Eileen , Grinberg Asya , Werner Eric D. , Glatt Vaida , Stadmeyer Lisa , Smith Deanna , Seehra Jasbir , Bouxsein Mary L.
Published: May 2008

Diseases that affect the regulation of bone turnover can lead to skeletal fragility and increased fracture risk. Members of the TGF-β superfamily have been shown to be involved in the regulation of bone mass. Activin A, a TGF-β signaling ligand, is present at high levels in bone and may play a role in the regulation of bone metabolism. Here we demonstrate that pharmacological blockade of ligand signaling through the high affinity receptor for activin, type II activin receptor (ActRIIA), by administration of the soluble extracellular domain of ActRIIA fused to a murine IgG2a-Fc, increases bone formation, bone mass, and bone strength in normal mice and in ovariectomized mice with established bone loss. These observations support the development of this pharmacological strategy for the treatment of diseases with skeletal fragility.
The evolution of modularity in bacterial metabolic networks
Authors: Kreimer Anat , Borenstein Elhanan , Gophna Uri , Ruppin Eytan
Published: May 2008

Deciphering the modular organization of metabolic networks and understanding how modularity evolves have attracted tremendous interest in recent years. Here, we present a comprehensive large scale characterization of modularity across the bacterial tree of life, systematically quantifying the modularity of the metabolic networks of >300 bacterial species. Three main determinants of metabolic network modularity are identified. First, network size is an important topological determinant of network modularity. Second, several environmental factors influence network modularity, with endosymbionts and mammal-specific pathogens having lower modularity scores than bacterial species that occupy a wider range of niches. Moreover, even among the pathogens, those that alternate between two distinct niches, such as insect and mammal, tend to have relatively high metabolic network modularity. Third, horizontal gene transfer is an important force that contributes significantly to metabolic modularity. We additionally reconstruct the metabolic network of ancestral bacterial species and examine the evolution of modularity across the tree of life. This reveals a trend of modularity decrease from ancestors to descendants that is likely the outcome of niche specialization and the incorporation of peripheral metabolic reactions.
Different assemblies of the DAM1 complex follow shortening microtubules by distinct mechanisms
Authors: Grishchuk E. L. , Spiridonov I. S. , Volkov V. A. , Efremov A. , Westermann S. , Drubin D. , Barnes G. , Ataullakhanov F. I. , McIntosh J. R.
Published: May 2008

Mitotic chromosomes segregate at the ends of shortening spindle microtubules (MTs). In budding yeast, the Dam1 multiprotein complex supports this dynamic attachment, thereby contributing to accurate chromosome segregation. Purified Dam1 will track the end of a depolymerizing MT and can couple it to microbead transport
in vitro
. The processivity of such motions has been thought to depend on rings that the Dam1 complex can form around MTs, but the possibility that alternative coupling geometries contribute to these motilities has not been considered. Here, we demonstrate that both rings and nonencircling Dam1 oligomers can track MT ends and enable processive cargo movement
in vitro
. The coupling properties of these two assemblies are, however, quite different, so each may make a distinct contribution to chromosome motility.
When to offer cognitive behavioural or psychoanalytic psychotherapy in an integrated psychotherapy service: Are everyday allocation decisions theoretically congruent?
Authors: Warden Sharon , Ricketts Tom , Saxon David , Houghton Simon , St. Ledger Sara , Curran Joe , Fitzgerald Gearoid
Published: May 2008

Different modes of psychotherapy can be an effective form of treatment for a range of mental health problems. Psychotherapy provision in the NHS is organised in a variety of ways, with patient entry to various modes of therapy determined by a range of factors including evidence‐based guidelines and patient or referrer preference. The methods by which patients arrive at a particular mode of psychotherapy are largely unreported. This paper aims to describe this process in one UK NHS psychotherapy service offering cognitive behavioural and psychoanalytic psychotherapy, and provides data to inform a discussion on the theoretical congruence of these allocation decisions.
Preparing our future counselling professionals: Gatekeeping and the implications for research
Authors: Brear Pamela , Dorrian Jillian , Luscri Giuseppa
Published: May 2008

Social science research specific to the identification and prevalence of unsuitable students within counselling, psychology, and social work training programmes is briefly reviewed in this article. This area of enquiry relates to the gatekeeping responsibilities of professional educational programmes, to ensure that their graduates are competent to provide ethical and effective practice to the public. Key issues which impede the usefulness of this gatekeeping literature to counselling educators are raised. These include: methodological inconsistencies which limit the comparison of findings and hence the drawing of sound conclusions; the lack of definitional clarity relating to the construct of gatekeeping; and the confusing array of nomenclature used to represent students’ failure to meet acceptable professional standards. It is apparent from this overview that there are common factors irrespective of nomenclature that are associated with students at risk of not becoming competent entry‐level practitioners. This suggests that a structured approach to terminology is appropriate. There is also evidence to suggest that encountering such students is a regular occurrence for faculty, with students indicating higher numbers of impaired students than educators. A working definition of gatekeeping is provided and nomenclature suggested.
Online counselling: The experience of counsellors providing synchronous single‐session counselling to young people
Authors: Bambling Matthew , King Robert , Reid Wendy , Wegner Karly
Published: May 2008

Kids Help Line (KHL) is a national Australian youth counselling service that provides free online and telephone counselling. This qualitative study examines the experience of 26 online KHL counsellors. Using a focus group methodology, counsellor responses were organised into categories: privacy and an emotionally safe environment; communication through text; and time. Counsellors reported the main benefit of the online environment to be emotional safety, due to reduced client emotional proximity to the counsellor, and the main disadvantage to be that reduced emotional proximity and the absence of non‐verbal cues could result in communication problems and difficulty in accurately assessing young people's concerns. Time proved a significant issue for counsellors, as the slow speed of text exchange could limit their ability to complete interventions. Methods that enhance both the process and effectiveness of online counselling are needed. Potential solutions to the challenges faced by online counsellors are discussed.
Antipsychotic polypharmacy in the emergency treatment of highly aggressive schizophrenic prisoners ‐ a retrospective study
Authors: Witzel Joachim G. , Gubka Udo , Weisser Heike , Bogerts Bernhard
Published: May 2008

In past years, Zuclopenthixolacetate as well as Flupentixoldecanoate have each proven to be reliable and efficient in the treatment of schizophrenic psychoses. In a specially implemented psychiatric treatment unit (PTU) we administered a high‐dose depot neuroleptic combination therapy initially consisting of both substances to seriously ill schizophrenic prisoners who exhibited highly aggressive behaviour (N = 20). We initially used both antipsychotics at the same time as a simple regimen in
order to restore the prisoners’ health to enable them to return to their home prisons. A single coercive intervention was performed in 14 out of 20 prisoners which was followed by a second one in two cases according to Article 101 of the German Code of Criminal Procedure. On average, prisoners needed a treatment course of 30.4 days. Within this time PANSS global scores were reduced by approximately 40%. Side effects occurring as a consequence of neuroleptic treatment were negligible and could be
dealt with.
Could recidivism in prisoners be linked to traumatic grief? A review of the evidence
Authors: Leach Raelene M. , Burgess Teresa , Holmwood Chris
Published: May 2008

Traumatic grief arises as a result of interpersonal trauma experienced as a betrayal of attachment. The distinct set of symptoms associated with it were first recognized in the 1990s. Losses associated with traumatic grief can be either death or non‐death related. A variety of studies have demonstrated that many prisoners have suffered from losses and trauma throughout their lives, and in many instances they have never received any support or interventions to address resultant problems. This paper examines whether there could be a relationship between many of the maladaptive behaviours demonstrated by the prisoners (including substance use), mental illness and traumatic grief. Of particular importance is the exploration of whether the high rates of recidivism seen in many developed countries (and which in Australia have been reported as high as 77%) may be related to traumatic grief. This paper explores new concepts that may be relevant to the development of strategies to reduce recidivism.
The health needs of imprisoned female juvenile offenders: The views of the young women prisoners and youth justice professionals
Authors: Douglas Nicola , Plugge Emma
Published: May 2008

Little is known about the health needs of detained juvenile females, yet there is emerging concern regarding substance misuse, mental health problems, poor sexual health and poorer general physical health on a range of indicators. This study sought to identify health needs from the perspective of imprisoned young women themselves and key professionals working with them to inform healthcare provision. We conducted semi‐structured interviews and focus groups with detained juvenile women and adult professionals in four specialist female young offender institutions. The study presents new qualitative findings on the profound impact of social exclusion and multiple forms of abuse and victimisation on the health of juvenile women prisoners. Concerns regarding substance misuse, mental health problems, self‐harm and poor sexual health are reinforced by this study. Young women
tended to focus on their immediate health needs in contrast to the professionals who emphasised longer‐term issues. The study identified the need for priority interventions in relation to mental health, substance misuse, self‐harm and sexual health and tentatively suggests that ‘compensatory care’may offer some scope to redress health inequalities experienced by these young women.
MATERIAL DEFORMATION
Authors: Ghoniem Nasr M. , Walgraef Daniel D.
Published: May 2008

This chapter discusses the main elements of continuum theory, which will be utilized further in later sections dealing with a variety of applications. First, a basic review of vector and tensor operations is presented, followed by descriptions of stress and strain tensors, and their relationships through thermodynamic functions. The special conditions of anisotropic crystals are also discussed. Green's tensor functions are derived for the displacement field of a material in response to a point force, for both isotropic and anisotropic crystals. Then, the methods of Eshelby for inclusions and inhomogeneities are presented, with analytical solutions to special problems of a second phase within a perfect crystals. This is followed by a presentation of the basic elements of crystal plasticity, and its connection with dislocation (or incompatibility) fields. The elastic fields of complex dislocation loop ensembles are finally given for both isotropic and anisotropic crystals.
TRANSPORT PHENOMENA
Authors: Ghoniem Nasr M. , Walgraef Daniel D.
Published: May 2008

This chapter focuses on the development of conservation and kinetic equations which govern nonequilibrium material processes. First, it discusses the concepts of mass and mass species conservation. Mass balance equations are developed in the general case, where transport is occurring simultaneously with chemical reactions. This is followed by a discussion of the conservation equations of momentum and energy, which is given in a form that is useful for solving practical problems in material processes. The thermodynamics of irreversible processes are then used to derive equations for mass and heat flow. Diffusion in solids is discussed from both microscopic and macroscopic viewpoints. Finally, it is shown that the Onsager reciprocity relations can provide links between the transport of heat, mass, and electric current, which is generally encountered in CVD and plasma processing of materials.
BENEFITS AND PERILS OF INSTABILITIES
Authors: Ghoniem Nasr M. , Walgraef Daniel D.
Published: May 2008

The chapter focuses on material instabilities. Topics discussed include the making and breaking of materials, thermo-chemical fabrication of new materials, thermo-mechanical fabrication of new materials, benefits of self-organization, and perils of material instabilities.
RADIATION-INDUCED INSTABILITIES
Authors: Ghoniem Nasr M. , Walgraef Daniel D.
Published: May 2008

The irradiation of materials with energetic particles may induce drastic changes in their microstructure, and hence may induce important variations in their physicochemical properties. This chapter discusses the phase stability of metals and alloys under irradiation, self-organization of defect microstructure, the rate theory of microstructure self-organization, nonlinear evolution dynamics, dislocation and void dynamics, and spatial instability.
SOLIDIFICATION AND ELECTRO-DEPOSITION
Authors: Ghoniem Nasr M. , Walgraef Daniel D.
Published: May 2008

This chapter examines the morphological instabilities of interfaces between the liquid and solid phases as the phase transformation process is completed. It first presents the problem of melting and solidification, in which the classical ‘Stefan problem’ is introduced as a fundamental model upon which melting and solidification studies are based. It then discusses some general aspects of phase change in pure, single-species systems. The attractiveness of the Stefan problem stems from the fact that the model is amenable to analytical solutions, and as such, it furnishes the physical understanding of more complex analysis of coupled heat and mass transport in a binary system. It also leads to the analysis of morphological surface instabilities and dendrite formation. The emergence of interfacial morphological instabilities in electro-chemical deposition is studied, exposing the rich variety of interfacial structures that arise in this case.
Bias in size composition of chum salmon (Oncorhynchus keta) caught by a gillnet with a geometric series of mesh sizes, and its correction using gear intercalibration
Authors: Fukuwaka Masa-aki , Azumaya Tomonori , Davis Nancy D. , Nagasawa Toru
Published: May 2008

Fukuwaka, M., Azumaya, T., Davis, N. D., and Nagasawa, T. 2008. Bias in size composition of chum salmon (Oncorhynchus keta) caught by a gillnet with a geometric series of mesh sizes, and its correction using gear intercalibration. – ICES Journal of Marine Science, 65: 930–936. Some research gillnets with size combinations based on a geometric series have been used for research surveys underpinning the stock assessment of fresh-water and marine fish. We assessed a bias in size composition of chum salmon caught using a research gillnet consisting of ten different mesh sizes based on a geometric series of factor 1.14. In all, 11 fishing operations were conducted for gear intercalibration between the research gillnet and a midwater trawl in the central Bering Sea. The best-fit selectivity model to pooled catch data included different fishing intensities among gillnet meshes. The pooled catch efficiency and the maximum catch efficiency of the gillnet increased with fish size. Estimated size composition of chum salmon was more similar to trawl catches than to research gillnet catches. Bias in size composition of research gillnet catches may be caused by the difference in encounter probability among mesh sizes, variability in fish swimming speed based on fish size, mesh visibility influencing fish behaviour, and diel vertical migration of chum salmon. When conducting multimesh gillnet surveys for stock assessment, researchers should correct a bias in size composition by performing gear intercalibrations.
Competition among plant species that interact with their environment at different spatial scales
Authors: Golubski Antonio J , Gross Katherine L , Mittelbach Gary G
Published: May 2008

Clonal plants that are physiologically integrated might perceive and interact with their environment at a coarser resolution than smaller, non-clonal competitors. We develop models to explore the implications of such scale asymmetries when species compete for multiple depletable resources that are heterogeneously distributed in space across two patches. Species are either ‘non-integrators’, whose growth in each patch depends on resource levels in that patch alone, or ‘integrators’, whose growth is equal between patches and depends on average resource levels across patches. Integration carried both benefits and costs. It tended to be advantageous in poorer patches, where the integrators drew resources down further than the non-integrators (more easily excluding competitors) and might persist by using resources from richer adjacent patches. Integration tended to be disadvantageous in richer patches, where integrators did not draw resources down as far (creating an opportunity for competitors) and could be excluded due to the cost of supporting growth in poorer adjacent patches. Complementarity between patches (each rich in a separate resource) favoured integrators. Integration created new opportunities for local coexistence, and for delayed susceptibility of patches to invasion, but eliminated some opportunities for regional coexistence. Implications for the interpretations of species' zero net growth isoclines and
R
*
s are also discussed.
Population viscosity can promote the evolution of altruistic sterile helpers and eusociality
Authors: Lehmann Laurent , Ravigné Virginie , Keller Laurent
Published: May 2008

Because it increases relatedness between interacting individuals, population viscosity has been proposed to favour the evolution of altruistic helping. However, because it increases local competition between relatives, population viscosity may also act as a brake for the evolution of helping behaviours. In simple models, the kin selected fecundity benefits of helping are exactly cancelled out by the cost of increased competition between relatives when helping occurs after dispersal. This result has lead to the widespread view, especially among people working with social organisms, that special conditions are required for the evolution of altruism. Here, we re-examine this result by constructing a simple population genetic model where we analyse whether the evolution of a sterile worker caste (i.e. an extreme case of altruism) can be selected for by limited dispersal. We show that a sterile worker caste can be selected for even under the simplest life-cycle assumptions. This has relevant consequences for our understanding of the evolution of altruism in social organisms, as many social insects are characterized by limited dispersal and significant genetic population structure.
Towards humane end points: behavioural changes precede clinical signs of disease in a Huntington's disease model
Authors: Littin Kate , Acevedo Abraham , Browne William , Edgar Joanne , Mendl Mike , Owen Diane , Sherwin Chris , Würbel Hanno , Nicol Christine
Published: May 2008

The number of animals used in science is increasing, bringing a concomitant obligation to minimize suffering. For animals with progressive conditions, euthanasia at a ‘humane end point’ is advised if the end point is scientifically valid, predictive and accurate. Our aim was to test the hypothesis that behavioural changes would reliably precede clinical signs of disease in a progressive neurological model, using retrospective analysis. We observed 100 pair-housed female R6/1 transgenic Huntington's disease (HD) mice and 28 pair-housed female wild-type (WT) mice in standard- or resource-enriched cages. Disease progression was monitored until one member of each HD pair reached a pre-defined end point based on pathological symptoms (HD end). This mouse was then euthanized together with its cage mate (HD other) and any matched WT pairs. At euthanasia, HD mice had significantly greater absolute and relative organ weights, and significantly higher α1 acid glycoprotein concentrations than WT mice, indicating reduced welfare. HD mice initially showed significantly greater use of cage resources than WT mice but this declined progressively. Steeper declines, and earlier cessation, in the use of some climbing and exploration resources occurred in the HD end mice compared with the HD other mice. Behavioural change can be an early indicator of disease onset.
On modelling physical systems with stochastic models: diffusion versus Lévy processes
Authors: Penland Cécile , Ewald Brian D
Published: May 2008

Stochastic descriptions of multiscale interactions are more and more frequently found in numerical models of weather and climate. These descriptions are often made in terms of differential equations with random forcing components. In this article, we review the basic properties of stochastic differential equations driven by classical Gaussian white noise and compare with systems described by stable Lévy processes. We also discuss aspects of numerically generating these processes.
Identification of a Xylogalacturonan Xylosyltransferase Involved in Pectin Biosynthesis inArabidopsis
Authors: Jensen Jacob Krüger , Sørensen Susanne Oxenbøll , Harholt Jesper , Geshi Naomi , Sakuragi Yumiko , Møller Isabel , Zandleven Joris , Bernal Adriana J. , Jensen Niels Bjerg , Sørensen Charlotte , Pauly Markus , Beldman Gerrit , Willats William G.T. , Scheller Henrik Vibe
Published: May 2008

Xylogalacturonan (XGA) is a class of pectic polysaccharide found in plant cell walls. The Arabidopsis thaliana locus At5g33290 encodes a predicted Type II membrane protein, and insertion mutants of the At5g33290 locus had decreased cell wall xylose. Immunological studies, enzymatic extraction of polysaccharides, monosaccharide linkage analysis, and oligosaccharide mass profiling were employed to identify the affected cell wall polymer. Pectic XGA was reduced to much lower levels in mutant than in wild-type leaves, indicating a role of At5g33290 in XGA biosynthesis. The mutated gene was designated xylogalacturonan deficient1 (xgd1). Transformation of the xgd1-1 mutant with the wild-type gene restored XGA to wild-type levels. XGD1 protein heterologously expressed in Nicotiana benthamiana catalyzed the transfer of xylose from UDP-xylose onto oligogalacturonides and endogenous acceptors. The products formed could be hydrolyzed with an XGA-specific hydrolase. These results confirm that the XGD1 protein is a XGA xylosyltransferase. The protein was shown by expression of a fluorescent fusion protein in N. benthamiana to be localized in the Golgi vesicles as expected for a glycosyltransferase involved in pectin biosynthesis.
Finite size effects on the real-space pair distribution function of nanoparticles
Authors: Gilbert Benjamin
Published: May 2008

The pair distribution function (PDF) method is a powerful approach for the analysis of the structure of nanoparticles. An important approximation used in nanoparticle PDF simulations is the incorporation of a form factor describing nanoparticle size and shape. The precise effect of the form factor on the PDF is determined by both particle shape and structure if these characteristics are both anisotropic and correlated. The correct incorporation of finite size effects is important for distinguishing and quantifying the structural consequences of small particle size in nanomaterials.
Correcting resolution bias in electron density maps of organic molecules derived by direct methods from powder data
Authors: Altomare Angela , Cuocci Corrado , Giacovazzo Carmelo , Moliterni Anna , Rizzi Rosanna
Published: May 2008

Fourier syntheses providing electron density maps are usually affected by truncation effects due to the limited data resolution. A recent theoretical approach [Altomare, Cuocci, Giacovazzo, Kamel, Moliterni & Rizzi (2008).Acta Cryst.A64, 326–336] suggests that the resolution bias may be reduced by correcting the current electron density maps in accordance with the physics of the diffraction experiment. We have implemented the approach inEXPO2004[Altomare, Caliandro, Camalli, Cuocci, Giacovazzo, Moliterni & Rizzi (2004).J. Appl. Cryst.37, 1025–1028], a program devoted to the solution of crystal structures from powder data. The new algorithm was applied at the end of the direct methods modulus, to verify if the reduction of the resolution bias is able to improve the electron density maps and to provide additional power to direct methods. Application of this method to a large set of test structures indicates that resolution-bias correction often makes the difference between success and failure, and thus constitutes a new tool for reducing the dependence of modern crystallography on resolution effects. The chances of failure are expected to depend on the quality of the experimental data (e.g.the accuracy of the full-pattern decomposition procedure and the data resolution), on the size of the structure and on its chemical composition.
Sure Start: voices of the ‘hard‐to‐reach’
Authors: Coe C. , Gibson A. , Spencer N. , Stuttaford M.
Published: May 2008

Objectives  This research aimed to look in depth at the factors affecting the ability of four Sure Start local programmes, based in a multicultural Midlands city, to engage with ‘hard‐to‐reach’ populations.

Methods  A variety of research strategies and methods were employed. Geographical information systems, participatory research methods and interviews were used in order to understand the extent of the challenge, and hear first hand, why parents may not get involved with Sure Start. The mapping exercise involved collation and mapping of postcode data with respect to boundaries and potential and actual users of Sure Start services. This made possible the identification of any geographical patterning in the distribution of service users and non‐users. Participatory research methods were used with parents, enabling them to conduct short interviews within their own communities and make sense of the data collected. Interviews were also conducted with 70 parents across the city, recruited through local schools.

Results  The results indicate that parental decisions regarding Sure Start are the product of a complex interaction between numerous factors which may act as either barriers or facilitators to service utilization.

Conclusions  The results suggest that a multi‐method approach to data collection is useful and appropriate in gaining access to those parents who are non‐users of the Sure Start services and enabling their voices to be heard. These findings offer some explanations and insight into the apparent ambivalent attitudes of some families toward Sure Start services. Implications for future practice are discussed.
Prevalence of overweight and obesity in urban and semi‐urban Jordanian children aged 3–6 years
Authors: Ibrahim A. I. , Hawamdeh Z. M. , Al‐Smadi J. T. , Ammari B. A.
Published: May 2008

Objectives  To show the prevalence of overweight and obesity among the Jordanian urban and semi‐urban children; to compare their body mass index (BMI) with the international standards of BMI.

Methods  We measured 1695 healthy children (842 boys and 853 girls) between 3 and 6 years for height, weight and mid upper arm circumference. BMI was calculated and transformed into percentiles. Children were divided into boys and girls.

Results  The mean and SD values of BMI observed in our study were 16.69 ± 4.9 kg/m2 for boys and 16.82 ± 4.77 kg/m2 for girls aged 3–6 years. The prevalence of obesity and overweight among boys was 20.8% and 3.8% respectively and among girls was 19.1% and 7.2% respectively. In total, 48.0% of boys and 38.1% of girls were of healthy weight.

Conclusions  The mean BMI observed in our study's children aged 3–6 years was higher than the expected 50th percentile of the (World Health Organization/Centers for Disease Control and Prevention) reference values for a similar age range but, it was equivalent to the 75th percentile values. Obesity was more frequent than overweight among boys and girls aged 3–6 years.
Are we following the European charter? Children, parents and staff perceptions
Authors: Migone M. , Mc Nicholas F. , Lennon R.
Published: May 2008

Background  In 1988, the European Association for Children in Hospital (EACH) established a charter of rights setting out the guiding principles for the treatment of children in hospital. Our aim was to ascertain whether children, parents and staff in a children's hospital believe the European Charter is conformed to.

Methods  A total of 111 parents (response rate = 90%), 50 children (response rate = 100%), 61 nurses (response rate = 55%) and 41 doctors (response rate = 25%) agreed to participate. Questionnaires based on the 10 rights in the EACH Charter were administered to children, parents and staff.

Results  The majority of children and parents were happy with the relationship they had with staff. However, the findings suggest that children, parents and staff are concerned with the lack of facilities in hospital, including parental accommodation, play, education, age‐appropriate wards and lack of privacy. Staff felt that many children undergo unnecessary admission and treatment in hospital. Many staff are reluctant to discuss issues such as side effects of medications with patients and do not encourage children to ask questions. Contrary to expectations, clinicians were reluctant to consider children under 16 as capable of giving consent, and most parents and children felt that children should be over 17 and 18 respectively.

Conclusion  This paper highlights patients' and staff's perceptions regarding children's rights in hospital and discusses the changes needed to fully conform to the EACH Charter.
Airway inflammation induced after allergic poly‐sensitization can be prevented by mucosal but not by systemic administration of poly‐peptides
Authors: Hufnagl K. , Focke M. , Gruber F. , Hufnagl P. , Loupal G. , Scheiner O. , Wiedermann U.
Published: May 2008

Background
Patients with multiple sensitizations require alternative forms of treatment, as the efficacy of conventional immunotherapy is unsatisfactory.

Objective
In the present study, we sought to compare the efficacy of a subcutaneously (s.c.) and a mucosally applied polyvalent vaccine to reduce allergic immune responses within airway and lung tissues.

Methods
Female BALB/c mice were intraperitoneally immunized with recombinant (r)Bet v 1, rPhl p 1 and rPhl p 5, followed by an aerosol challenge of birch and phleum pollen extract. For tolerance induction, either a mixture of the immunodominant peptides or a hybrid peptide of the respective antigens was s.c. injected or intranasally applied before poly‐sensitization.

Results
Mucosal but not systemic pre‐treatment with poly‐peptides led to significant suppression of eosinophils and IL‐5 production in bronchoalveolar lavages, as well as IL‐5, IL‐4, IL‐13 and eotaxin levels in lung cell cultures. Lung histology showed a clear reduction of cellular infiltration and mucus production only in intranasally pre‐treated mice. In accordance, also the systemic immune response, characterized by IgE‐dependent basophil degranulation and IL‐4 levels in vitro, was significantly reduced by mucosal antigen application, but only marginally influenced by subcutaneous pre‐treatment. Both treatment routes led to up‐regulated CTLA4 expression in splenocytes, whereas only after mucosal pre‐treatment Foxp3 expression levels were enhanced in lung CD3+ T cells. Furthermore, intranasal but not subcutaneous application of the peptides enhanced IL‐10 levels in the lungs, indicating regulatory mechanisms operating in local tolerance induction.

Conclusion
Mucosal application of peptides is superior to systemic application in preventing both local and systemic poly‐allergic T helper2 immune responses, suggesting mucosal tolerance induction as an attractive strategy for the primary and secondary prevention of allergic multi‐sensitization and lung pathology.
How the presence of rhinoconjunctivitis and the severity of asthma modify the relationship between obesity and asthma in children 6–7 years old
Authors: Garcia‐Marcos L. , Arnedo Pena A. , Busquets‐Monge R. , Morales Suárez‐Varela M. , García de Andoin N. , Batlles‐Garrido J. , Blanco‐Quirós A. , López‐Silvarrey Varela A. , García‐Hernández G. , Aguinaga‐Ontoso I. , González‐Díaz C. , Garcia‐Merino A.
Published: May 2008

Background
The association between asthma and obesity in children, and the effect modification of allergy on this association have not been fully established.

Aims
The objective of the study was to know the effect modification of the severity of asthma and of the coexistence of rhinoconjunctivitis (RC) in the relationship between obesity and asthma.

Methods
A cross‐sectional study of 17 145 schoolchildren 6–7 years old from eight Spanish cities who had completed information on height and weight of the ISAAC phase III questionnaire, which also included questions about asthma and RC symptoms and on various risk factors. Body mass index (BMI) was used to define obesity according to international standards. Two different logistic regressions, using current occasional asthma (COA) and current severe asthma (CSA) as dependent variables, were made stratifying for gender and for the coexistence of RC and controlling for age, older and younger siblings, exercise, mother's education, truck traffic, cat/dog during the first year of life and smoking father or mother.

Results
Obesity was a risk factor of CSA without RC, both for boys (1.92, CI 95% 1.13–3.25) and for girls (2.99, CI 95% 1.68–5.32). Every BMI unit increment increased by 6.7% the risk of CSA without RC in boys and by 12.4% in girls. Obesity was not a risk factor for CSA with RC. The association between COA and obesity was weaker and the coexistence of RC did not modify it greatly.

Conclusions
Obese schoolchildren are more at risk of suffering from non‐allergic asthma than the non‐obese subjects.
Hypertonic saline cough provocation test with salbutamol pre‐treatment: evidence for sensorineural dysfunction in asthma
Authors: Koskela H. O. , Purokivi M. K. , Kontra K. M. , Taivainen A. H. , Tukiainen H. O.
Published: May 2008

Background
Cough is one of the most common symptoms of asthma. However, studies using capsaicin, citric acid, or tartaric acid to document cough threshold have repeatedly failed to show statistically significant differences between asthmatic and healthy subjects. The studies using hypertonic aerosols as the cough stimulant have suggested an enhanced sensitivity in asthmatic subjects but the induced bronchoconstriction has made the interpretation of the results difficult.

Objective
To determine the cough sensitivity to hypertonicity in healthy subjects, patients with chronic cough, and patients with asthma in a setting where the induction of bronchoconstriction is prevented.

Methods
Nineteen healthy subjects, 21 non‐asthmatic patients with chronic cough, and 26 asthmatic patients with chronic cough underwent an incremental hypertonic saline challenge including a pre‐treatment with 0.4 mg of salbutamol. Spirometry was performed before the challenge, after salbutamol, and after the challenge. The patients with cough also underwent skin testing, histamine challenge, exhaled nitric oxide measurement, ambulatory peak flow monitoring, kept cough diary, and filled in the Leicester Cough Questionnaire. Eighteen patients repeated the saline challenge.

Results
The challenge did not induce bronchoconstriction in any group. The osmolality to provoke 15 cumulative coughs was significantly smaller in the asthmatic patients than in the healthy subjects (P<0.001) and in the cough patients without asthma (P=0.04). According to multivariate analysis among all the 47 patients with cough, female sex (P<0.001) and large spontaneous peak flow variation in the ambulatory recording (P=0.001) were associated with high sensitivity to saline. The saline challenge response was well repeatable (intraclass correlation coefficient 0.90).

Conclusion
The findings of the present study are not affected by induced bronchoconstriction. Asthma or, more specifically, spontaneous, reversible airway obstruction is associated with an enhanced sensitivity to the cough‐provoking effect of hypertonic saline. This suggests a pathological function of the sensorineural apparatus in this disorder.
Avoidance of egg parasitism through submerged oviposition by tandem pairs in the water strider, Aquarius paludum insularis (Heteroptera: Gerridae)
Authors: AMANO HIDEKI , HAYASHI KOOJI , KASUYA EIITI
Published: May 2008

Abstract 1. Females of the water strider Aquarius paludum insularis (Motschulsky) (Heteroptera: Gerridae) carry males on their backs and oviposit under water after copulation. This study focuses on the benefit A. paludum insularis receives by ovipositing in tandem.

2. Males guarded females in tandem through to the end of oviposition in 85% of copulations. Females in tandem dived deeper than single females, and the density of A. paludum insularis eggs increased with water depth. The proportion of eggs parasitized by a scelionid wasp, Tiphodytes gerriphagus Marchal (Hymenoptera: Scelionidae) decreased with increasing water depth.

3. These results suggest that during oviposition guarding by males is beneficial for females, because it enables pairs to dive and lay eggs deeper and in oviposition sites where the risk of egg parasitism is lower.
Avoidance of the host immune response by a generalist parasitoid,Compsilura concinnataMeigen
Authors: CARON VALERIE , JANMAAT ALIDA F. , ERICSSON JERRY D. , MYERS JUDITH H.
Published: May 2008

Abstract1. Ecological interactions between parasitoids and their hosts are extremely strong as parasitoid offspring rely entirely on an individual host to complete development. The ability of a parasitoid to use a host is influenced directly by the degree to which the parasitoid can overcome host defences and grow within the host.

2. Hymenopteran parasitoids have evolved different host‐specific strategies to defeat the host immune system, such as the use of venom, endosymbiont virus, or mimicking the host tissue. Dipteran parasitoids from the Tachinidae family do not use these subterfuges and rely mainly on avoiding the host immune system by hiding in specific tissues.

3. Little is known of the effect of this strategy on the host immune system, the absorption of nutrients by the parasitoid larvae, or the implications for parasitoid host range.

4. In this study, the impact of a polyphagous tachinid parasitoidCompsilura concinnataMeigen on a pest lepidopteranTrichoplusia niHübner are assessed. Phenoloxidase levels and haemolymph proteins were measured in parasitisedT. nias a function of host immune response.

5. Haemolymph phenoloxidase in the host did not vary with parasitisation but was triggered when a piece of monofilament was implanted in the haemocoel. Haemolymph proteins were depleted in heavily parasitisedT. ni.

6. These results indicate thatC. concinnatahas a strategy that avoids the host immune system, and accesses the necessary nutrients for larval growth. This strategy could explain the success of this tachinid and its wide host range.
Life‐history strategy in an oligophagous tephritid: the tomato fruit fly, Neoceratitis cyanescens
Authors: BRÉVAULT THIERRY , DUYCK PIERRE‐FRANÇOIS , QUILICI SERGE
Published: May 2008

Abstract 1. In phytophagous insects, life‐history traits mainly depend on host plant range. Substantial longevity, high fecundity and larval competition are the major traits of polyphagous Tephritidae while species with a restricted host range generally exhibit a lower longevity and fecundity as well as mechanisms to avoid larval competition. Our aim in this study was to investigate the life history of an oligophagous species, the tomato fruit fly, Neoceratitis cyanescens (Bezzi).

2. We determined life tables under laboratory conditions in order to calculate the main demographic parameters of N. cyanescens and studied the influence of larval and adult diet on life‐history traits.

3. The mean longevity of N. cyanescens females was 40 days. There was a strong synchronisation of female maturity. Oviposition showed an early peak at 9–13 days after a short pre‐oviposition period (6 days). The absence of proteins in the adult diet both delayed ovarian maturation and decreased female fecundity. In addition, females originating from tomato fruits produced significantly more eggs than females originating from bugweed or black nightshade, showing that even the larval host plant may strongly affect the subsequent fecundity of adult females.

4. The traits of N. cyanescens are then discussed in the light of those documented for polyphagous and monophagous tephritids. Neoceratitis cyanescens displayed attributes intermediate between those of polyphagous and monophagous tephritids. Its smaller clutch size compared with polyphagous species and its specialisation on the Solanaceae family whose fruits contain toxic compounds may help in reducing intra‐ and inter‐specific competition, respectively.