bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection and mobility of hafnium in SiO2
Authors: Klenov Dmitri O. , Mates Thomas E. , Stemmer Susanne
Published: August 2006

High-angle annular dark-field imaging in scanning transmission electron microscopy and x-ray photoelectron spectroscopy were used to investigate thermal SiO2 layers doped with Hf by ion implantation. Hf was mobile under the focused electron beam in the as-implanted samples. After annealing for 5min at 1200°C, clusters of crystalline HfO2 were observed that were a few nanometers in size and surrounded by residual Hf that had remained trapped in the SiO2. Hf was not mobile under the electron beam in the annealed samples. Further annealing caused an expansion of the SiO2 that was damaged by ion implantation. Hf rearrangement was confined to the ion beam damaged regions of the SiO2 layer. No diffusion of Hf into the undamaged SiO2 was observed. The implications of the results for complementary metal-oxide-semiconductor transistors with HfO2 gate dielectrics are discussed.
Polymer-bridged gels of nanoparticles in solutions of adsorbing polymers
Authors: Surve Megha , Pryamitsyn Victor , Ganesan Venkat
Published: August 2006

We use a combination of polymer mean field theory and Monte Carlo simulations to study the polymer-bridged gelation, clustering behavior, and elastic moduli of polymer-nanoparticle mixtures. Polymer self-consistent field theory is first numerically implemented to quantify both the polymer induced interparticle interaction potentials and the conformational statistics of polymer chains between two spherical particles. Subsequently, the formation and structure of polymer-bridged nanoparticle gels are examined using Monte Carlo simulations. Our results indicate a universality in the fractal structure for the polymer-bridged networks over a wide range of parametric conditions. Explicitly, near the gelation transition, the fractal dimension df ranges between 2.2 and 2.5, and above the gelation thresholds, the elastic moduli are found to follow a universal power law G′∝(η−ηc)νη with a critical exponent νη≈1.82. The latter suggests strong similarities between polymer-bridging induced percolation and classical elastic resistor network percolation. Our results show a very good agreement with the experimental results for polymer-particle mixtures and suggest a possible framework for experimentally distinguishing the origins of gelation phenomena observed in polymer-particle mixtures.
Ultranarrow band and high-quantum-efficiency photoresponse of Ge-on-Si photodetectors using cascaded-cavity structure
Authors: Chen Jinlin , Zhou Zhiping
Published: August 2006

A resonant cavity mirror structure is incorporated into the top mirror of Ge-on-Si resonant cavity enhanced photodetectors to obtain ultranarrow band and high-quantum-efficiency photoresponse at the same time, which takes advantage of the combined effect of the top resonant cavity mirror and the absorption resonant cavity. The proposed structure is simulated and optimized by matrix method, resulting in a 3dB linewidth of 0.4nm and quantum efficiency of 96.8%. In addition, different reflectance profiles of the proposed structure are also presented, which can be used for different specific requirements.
Magnetic properties of FePt nanodots formed by a self-assembled nanodot deposition method
Authors: Yin C. K. , Fukushima T. , Tanaka T. , Koyanagi M. , Bea J. C. , Choi H. , Nishijima M. , Miyao M.
Published: August 2006

Fe 50 Pt 50 nanodots dispersed in a SiO2 film (Fe50Pt50 nanodot film) were formed by a self-assembled nanodot deposition (SAND) method in which Fe50Pt50 and SiO2 are cosputtered in a high vacuum rf magnetron sputtering equipment. Fe50Pt50 pellets are laid on a SiO2 target in a sputtering chamber to form the Fe50Pt50 nanodot film in the SAND method. The size and density of Fe50Pt50 nanodot were controlled by changing the ratio of the total area of Fe50Pt50 pellets to that of SiO2 target. The Fe50Pt50 nanodot size decreases and its density increases when the ratio decreases. As-deposited Fe50Pt50 nanodots self-assembled to a face-centered-cubic phase of single-crystal structure. The Fe50Pt50 nanodot films were annealed to evaluate the nanodot size controllability, the magnetic anisotropy, and the thermal stability. Fully ordered L10 face-centered-tetragonal Fe50Pt50 nanodots with high magnetocrystalline anisotropy (Ku≅8.7×107ergs∕cm3) were obtained by in situ annealing at 600°C for 1h in a high vacuum ambience. Furthermore, the Fe50Pt50 nanodot film with a monolayer of Fe50Pt50 nanodots was formed by annealing at 800°C due to the agglomeration of Fe50Pt50 nanodots in the SiO2 film.
Annealing of indium tin oxide films by electric current: Properties and structure evolution
Authors: Rogozin A. , Shevchenko N. , Vinnichenko M. , Seidel M. , Kolitsch A. , Möller W.
Published: August 2006

A method of annealing thin films of indium tin oxide in vacuum is proposed using a direct electric current flow through the film. During annealing at a constant electric power, the film resistance, free electron density, and structure evolution were monitored in situ. In comparison with the conventional isothermal annealing, the current annealing is more efficient providing a noticeable reduction in the thermal budget and a decrease in the kinetic exponent of crystallization. Electrical inhomogeneities in the film, which produce locally overheated regions, are discussed as a possible reason for the acceleration of the crystallization process.
Microstructure and piezoelectric properties of 0.95(Na0.5K0.5)NbO3–0.05BaTiO3 ceramics
Authors: Park Hwi-Yeol , Ahn Cheol-Woo , Song Hyun-Cheol , Lee Jong-Heun , Nahm Sahn , Uchino Kenji , Lee Hyeung-Gyu , Lee Hwack-Joo
Published: August 2006

For 0.95(Na0.5K0.5)NbO3–0.05BaTiO3 (0.95NKN-0.05BT) ceramics sintered at 1040–1075°C, abnormal grain growth occurred but the grain size decreased when the sintering temperature exceeded 1075°C. The dielectric constant (ϵ3T∕ϵ3), electromechanical coupling factor (kp), and piezoelectric constant (d33) were considerably increased with increasing relative density and grain size. Evaporation of Na2O deteriorated the piezoelectric properties by decreasing the resistivity. To minimize Na2O evaporation, specimens were muffled with 0.95NKN-0.05BT powders during the sintering. Improved piezoelectric properties of d33=225pC∕N, kp=36%, and ϵ3T∕ϵ3=1058 were obtained for specimen sintered at 1060°C for 2h with muffling.
Acoustic directional radiation and enhancement caused by band-edge states of two-dimensional phononic crystals
Authors: Qiu Chunyin , Liu Zhengyou
Published: August 2006

The authors numerically investigate the radiation of a line acoustic source placed inside a phononic crystal of square lattice. Their results show that it is possible to obtain a highly directional acoustic source with a large radiation enhancement, operating at the band-edge frequency of the phononic crystal. The angular distributions of the radiation power and the radiation enhancement factor are strongly dependent on the position of the acoustic source relative to the unit cell in which it is placed. A simple realization of a highly directional acoustic source with a half-power angular width of about 5.2° is presented.
Molecular modeling of low-k films of carbon-doped silicon oxides for theoretical investigations of the mechanical and dielectric properties
Authors: Tajima N. , Ohno T. , Hamada T. , Yoneda K. , Kobayashi N. , Hasaka S. , Inoue M.
Published: August 2006

For theoretical studies on the mechanical and dielectric properties of low dielectric constant (low-k) films of carbon doped SiO2 (SiOCH), the authors developed a method to create molecular models of amorphous polymers with cross-links. This method generates chemically possible molecular structures from a given atom-group composition. They have applied this method to the molecular modeling of a typical SiOCH low-k film which is made by plasma enhanced chemical vapor deposition. They have confirmed that this method creates reasonable SiOCH film structures that explain the experimental results of infrared spectrum, dielectric constant, and Young’s modulus.
Adaptive responses of wild mungbean (Vigna radiata ssp. sublobata) to photo-thermal environment. I. Phenology
Authors: Rebetzke G. J. , Lawn R. J.
Published: August 2006

The phenology of 11 diverse accessions of wild mungbean was observed under natural and artificial photoperiod–temperature conditions, in order to examine whether genotypic differences might be attributed to adaptive responses to photo-thermal conditions. There was large variation in phenological response among accessions and across environments, much of which was due to differences in the duration of the pre-flowering phase. Accessions that flowered earlier tended to flower for longer, apart from 2 earlier flowering, inland Australian lines that were also earlier maturing. The patterns of response in time from sowing to flowering over environment were consistent with quantitative short-day photoperiodic adaptation, a conclusion supported by the effects of artificial day-length extension and by ‘goodness of fit’ of the observed responses to standard models relating rate of development to photoperiod and temperature. The fitted models indicated that rate of development towards flowering was hastened by warmer temperatures, and delayed by longer day lengths, with differential sensitivity between accessions to both factors. The models also suggested that photoperiod was more important for accessions collected closer to the equator, which were generally later flowering as a consequence. Conversely, temperature was relatively more important in lines from higher latitudes. Modelling also suggested that the period from first flowering to maturity was sensitive to photoperiod and temperature. Again, longer days appeared to prolong growth and delay maturity. However, cooler temperatures accelerated rather than slowed maturity, by suppressing further vegetative growth. The variation observed indicated that there is considerable scope for using the wild population to broaden the adaptation of cultivated mungbean. In particular, the unusual response of a late-flowering, photoperiod-insensitive accession warrants further study to establish whether the wild population contains a unique ‘long juvenile’ trait analogous to that being used for improving phenological adaptation in soybean.
Adaptive responses of wild mungbean (Vigna radiata ssp. sublobata) to photo-thermal environment. II. Growth, biomass, and seed yield
Authors: Rebetzke G. J. , Lawn R. J.
Published: August 2006

The leaf growth, dry matter production, and seed yield of 11 wild mungbean (Vigna radiata ssp. sublobata) accessions of diverse geographic origin were observed under natural and artificial photoperiod–temperature conditions, to determine the extent to which genotypic differences could be attributed to adaptive responses to photo-thermal environment. Environments included serial sowings in the field in SE Queensland, complemented by artificial photoperiod extension and controlled-environment growth rooms. Photo-thermal environment influenced leaf growth, total dry matter production (TDM), and seed yield directly, through effects of (mainly cool) temperature on growth, and indirectly, through effects on phenology. In terms of direct effects, leaf production, leaf expansion, and leaf area were all sensitive to temperature, with implied base temperatures higher than usually observed in cultivated mungbean (V. radiata ssp. radiata). Genotypic sensitivity to temperature varied systematically with accession provenance and appeared to be of adaptive significance. In terms of the indirect effects of photo-thermal environment, genotypic and environmental effects on TDM were positively related to changes in total growth duration, and harvest index was negatively related to the period from sowing to flowering, similar to cultivated mungbean. However, seed yield was positively related to the duration of reproductive growth, reflecting the indeterminate growth habit of the wild accessions. As a consequence, the wild accessions are more responsive to favourable environments than typically observed in cultivated mungbean, which is determinate in habit. It is suggested that the introduction of the indeterminate trait into mungbean from the wild subspecies would increase the responsiveness of mungbean to favourable environments, analogous to that of black gram (V. mungo). Although the wild subspecies appeared more sensitive to cool temperature than cultivated mungbean, it may provide a source of tolerance to the warmer temperatures experienced during the wet season in the tropics.
Wolbachiatransinfection inAedes aegypti: A potential gene driver of dengue vectors
Authors: Ruang-areerate Toon , Kittayapong Pattamaporn
Published: August 2006

The endosymbiotic bacteria in the genusWolbachiaare capable of inducing a wide range of reproductive abnormalities in their hosts, including cytoplasmic incompatibility (CI), which could lead to the replacement of uninfected host populations with infected ones. Because of this,Wolbachiahave attracted considerable interest as a potential mechanism for spreading disease-blocking transgenes through vector populations. Here we report the establishment of doubleWolbachiatransinfection by direct adult microinjection ofWolbachiafrom naturally double-infectedAedes albopictustoAedes aegypti, the most important mosquito vector of infectious viral diseases, and a mosquito in which naturalWolbachiainfections are not known to occur. We further demonstrate that incomplete CI is induced in these double-transinfected mosquitoes. Comparisons of fitness traits between naturally uninfected and transinfectedAe. aegyptilines indicated one significant difference in favor of the latter, namely, an increased number of eggs laid. Levels of CI expression corresponded to theWolbachiadensity. There were large differences in relativeWolbachiadensity between reproductive and nonreproductive tissues in bothAe. albopictusand transinfectedAe. aegypti, except Malpighian tubule, which implied the preferred establishment ofWolbachiawithin reproductive tissue. Results from a simulation model confirm that population replacement by transinfectedAe. aegyptiis possible over time. The establishment ofWolbachiadouble infections inAe. aegyptiby direct adult microinjection and the demonstration of CI expression in this new host suggest thatWolbachiacould be experimentally transferred into vector species and could also be used as a gene-driving system to genetically manipulate vector populations.
Metabolic profiling reveals a contribution of gut microbiota to fatty liver phenotype in insulin-resistant mice
Authors: Dumas Marc-Emmanuel , Barton Richard H. , Toye Ayo , Cloarec Olivier , Blancher Christine , Rothwell Alice , Fearnside Jane , Tatoud Roger , Blanc Véronique , Lindon John C. , Mitchell Steve C. , Holmes Elaine , McCarthy Mark I. , Scott James , Gauguier Dominique , Nicholson Jeremy K.
Published: August 2006

Here, we study the intricate relationship between gut microbiota and host cometabolic phenotypes associated with dietary-induced impaired glucose homeostasis and nonalcoholic fatty liver disease (NAFLD) in a mouse strain (129S6) known to be susceptible to these disease traits, using plasma and urine metabotyping, achieved by
1
H NMR spectroscopy. Multivariate statistical modeling of the spectra shows that the genetic predisposition of the 129S6 mouse to impaired glucose homeostasis and NAFLD is associated with disruptions of choline metabolism, i.e., low circulating levels of plasma phosphatidylcholine and high urinary excretion of methylamines (dimethylamine, trimethylamine, and trimethylamine-
N
-oxide), coprocessed by symbiotic gut microbiota and mammalian enzyme systems. Conversion of choline into methylamines by microbiota in strain 129S6 on a high-fat diet reduces the bioavailability of choline and mimics the effect of choline-deficient diets, causing NAFLD. These data also indicate that gut microbiota may play an active role in the development of insulin resistance.
Model-based analysis of tiling-arrays for ChIP-chip
Authors: Johnson W. Evan , Li Wei , Meyer Clifford A. , Gottardo Raphael , Carroll Jason S. , Brown Myles , Liu X. Shirley
Published: August 2006

We propose a fast and powerful analysis algorithm, titled Model-based Analysis of Tiling-arrays (MAT), to reliably detect regions enriched by transcription factor chromatin immunoprecipitation (ChIP) on Affymetrix tiling arrays (ChIP-chip). MAT models the baseline probe behavior by considering probe sequence and copy number on each array. It standardizes the probe value through the probe model, eliminating the need for sample normalization. MAT uses an innovative function to score regions for ChIP enrichment, which allows robust
P
value and false discovery rate calculations. MAT can detect ChIP regions from a single ChIP sample, multiple ChIP samples, or multiple ChIP samples with controls with increasing accuracy. The single-array ChIP region detection feature minimizes the time and monetary costs for laboratories newly adopting ChIP-chip to test their protocols and antibodies and allows established ChIP-chip laboratories to identify samples with questionable quality that might contaminate their data. MAT is developed in open-source Python and is available at
http://chip.dfci.harvard.edu/∼wli/MAT
. The general framework presented here can be extended to other oligonucleotide microarrays and tiling array platforms.
Viral tracing identifies distributed columnar organization in the olfactory bulb
Authors: Willhite David C. , Nguyen Katherine T. , Masurkar Arjun V. , Greer Charles A. , Shepherd Gordon M. , Chen Wei R.
Published: August 2006

Olfactory sensory neurons converge onto glomeruli in the olfactory bulb (OB) to form modular information processing units. Similar input modules are organized in translaminar columns for other sensory modalities. It has been less clear in the OB whether the initial modular organization relates to a columnar structure in the deeper layers involved in local circuit processing. To probe synaptic connectivity in the OB, we injected a retrograde-specific strain of the pseudorabies virus into the rat OB and piriform cortex. The viral-staining patterns revealed a striking columnar organization that extended across all layers of the OB from the glomeruli to the deep granule cell layer. We hypothesize that the columns represent an extension of the glomerular unit. Specific patterning was observed, suggesting selective, rather than distance-dependent, center-surround connectivity. The results provide a previously undescribed basis for interpreting the synaptic connections between mitral and granule cells within the context of a columnar organization in the OB and have implications for olfactory coding and network organization.
Calbindin D
9k
knockout mice are indistinguishable from wild-type mice in phenotype and serum calcium level
Authors: Kutuzova Galina D. , Akhter Shirin , Christakos Sylvia , Vanhooke Janeen , Kimmel-Jehan Christine , DeLuca Hector F.
Published: August 2006

Since the discovery of calbindin D
9k
, its role in intestinal calcium absorption has remained unsettled. Further, a wide distribution of calbindin D
9k
among tissues has argued for its biological importance. We discovered a frameshift deletion in the calbindin D
9k
gene in an ES cell line, E14.1, that originated from 129/OlaHsd mice. We produced mice with the mutant calbindin D
9k
gene by injecting the E14.1 ES cell subline into the C57BL/6 host blastocysts and proved that these mice lack calbindin D
9k
protein. Calbindin D
9k
knockout mice were indistinguishable from wild-type mice in phenotype, were able to reproduce, and had normal serum calcium levels. Thus, calbindin D
9k
is not required for viability, reproduction, or calcium homeostasis.
Identification of regulatory modules by co-clustering latent variable models: stem cell differentiation
Authors: Joung Je-Gun , Shin Dongho , Seong Rho Hyun , Zhang Byoung-Tak
Published: August 2006

Motivation: An important issue in stem cell biology is to understand how to direct differentiation towards a specific cell type. To elucidate the mechanism, previous studies have focused on identifying the responsible gene regulators, which have, however, failed to provide a systemic view of regulatory modules. To obtain a unified description of the regulatory modules, we characterized major stem cell species by employing a co-clustering latent variable model (LVM). The LVM-based method allowed us to elucidate the cell type-specific transcription factors, using genomic sequences as well as expression profiles.

Results: We used a list of genes enriched in each of 21 stem cell subpopulations, and their upstream genomic sequences. The LVM-based study allowed us to uncover the regulatory modules for each stem cell cluster, e.g. GABP and E2F for the proliferation phase, and Ap2α and Ap2γ for the quiescence phase. Furthermore, the identities of the stem cell clusters were well revealed by the constituent genes that were directly targeted by the modules. Consequently, our analytical framework was demonstrated to be useful through a detailed case study of stem cell differentiation and can be applied to problems with similar characteristics.

Contact:  btzhang@bi.snu.ac.kr, rhseong@snu.ac.kr

Supplementary Information: Supplementary data are available at .
MLR-tagging: informative SNP selection for unphased genotypes based on multiple linear regression
Authors: He Jingwu , Zelikovsky Alexander
Published: August 2006

Summary: The search for the association between complex diseases and single nucleotide polymorphisms (SNPs) or haplotypes has recently received great attention. For these studies, it is essential to use a small subset of informative SNPs accurately representing the rest of the SNPs. Informative SNP selection can achieve (1) considerable budget savings by genotyping only a limited number of SNPs and computationally inferring all other SNPs or (2) necessary reduction of the huge SNP sets (obtained, e.g. from Affymetrix) for further fine haplotype analysis.

A novel informative SNP selection method for unphased genotype data based on multiple linear regression (MLR) is implemented in the software package MLR-tagging. This software can be used for informative SNP (tag) selection and genotype prediction. The stepwise tag selection algorithm (STSA) selects positions of the given number of informative SNPs based on a genotype sample population. The MLR SNP prediction algorithm predicts a complete genotype based on the values of its informative SNPs, their positions among all SNPs, and a sample of complete genotypes.

An extensive experimental study on various datasets including 10 regions from HapMap shows that the MLR prediction combined with stepwise tag selection uses fewer tags than the state-of-the-art method of Halperin et al. (2005).

Availability: MLR-Tagging software package is publicly available at

Contact:  alexz@cs.gsu.edu
Robust inference of positive selection from recombining coding sequences
Authors: Scheffler Konrad , Martin Darren P. , Seoighe Cathal
Published: August 2006

Motivation: Accurate detection of positive Darwinian selection can provide important insights to researchers investigating the evolution of pathogens. However, many pathogens (particularly viruses) undergo frequent recombination and the phylogenetic methods commonly applied to detect positive selection have been shown to give misleading results when applied to recombining sequences. We propose a method that makes maximum likelihood inference of positive selection robust to the presence of recombination. This is achieved by allowing tree topologies and branch lengths to change across detected recombination breakpoints. Further improvements are obtained by allowing synonymous substitution rates to vary across sites.

Results: Using simulation we show that, even for extreme cases where recombination causes standard methods to reach false positive rates >90%, the proposed method decreases the false positive rate to acceptable levels while retaining high power. We applied the method to two HIV-1 datasets for which we have previously found that inference of positive selection is invalid owing to high rates of recombination. In one of these (env gene) we still detected positive selection using the proposed method, while in the other (gag gene) we found no significant evidence of positive selection.

Availability: A HyPhy batch language implementation of the proposed methods and the HIV-1 datasets analysed are available at . The HyPhy package is available at , and it is planned that the proposed methods will be included in the next distribution. RDP2 is available at .

Contact:  konrad@cbio.uct.ac.za, cathal@science.uct.ac.za
Effects of Warning and Information Labels on Attraction to Television Violence in Viewers of Different Ages
Authors: Bushman Brad J.
Published: August 2006

Warning labels on violent television programs give viewers discretionary advice and, therefore, might arouse reactance in viewers of all ages. Information labels give viewers information but no advice and, therefore, should not arouse reactance. Five age groups were tested: 9‐11 year olds, 12‐14 year olds, 15‐17 years olds, 18‐20 year olds, and adults at least 21 years old. Participants (N=900) read descriptions of violent and nonviolent TV programs and rated how much they wanted to watch them. The description contained a warning label, an information label, or no label. Consistent with reactance theory, results showed that warning labels drew people of all ages to violent TV programs. Information labels did not draw viewers to violent programs.
A Test of Self‐Determination Theory in the Exercise Domain
Authors: Edmunds Jemma , Ntoumanis Nikos , Duda Joan L.
Published: August 2006

In accordance with self‐determination theory (SDT; Deci & Ryan, 1985), this study examined the relationship between autonomy support, psychological need satisfaction, motivational regulations, and exercise behavior. Participants (N=369) were recruited from fitness, community, and retail settings. Fulfillment of the 3 basic psychological needs (i.e., competence, autonomy, and relatedness) related to more self‐determined motivational regulations. Identified and introjected regulations emerged as positive predictors of strenuous and total exercise behaviors. Competence need satisfaction also predicted directly—and indirectly via identified regulation—strenuous exercise. For participants engaged in organized fitness classes, perceptions of autonomy support provided by exercise class leaders predicted psychological need satisfaction. Furthermore, competence need satisfaction partially mediated the relationship between autonomy support and intrinsic motivation. These findings support SDT in the exercise domain.
Improving Customer Reactions to Electronic Brokered Ultimatums: The Benefits of Prior Experience and Explanations
Authors: Ellis Aleksander P. J. , Humphrey Stephen E. , Conlon Donald E. , Tinsley Catherine H.
Published: August 2006

Because of the growth of online discount travel intermediaries (e.g., Priceline), researchers have become interested in how customers react to electronic brokered ultimatum bargaining contexts. This paper investigates how characteristics of the customer and characteristics of the bargaining context might ameliorate customers' (a) perceptions of justice; (b) willingness to recommend the intermediary to others; and (c) willingness to repatronize the intermediary. We found that customer familiarity generally improved customer reactions to the electronic intermediary. We found a moderating effect for intermediary explanations in the form of an excuse, as explanations improved customer reactions when offers were rejected, but worsened reactions when offers were accepted.
On‐call stress among Finnish anaesthetists*
Authors: Lindfors P. M. , Nurmi K. E. , Meretoja O. A. , Luukkonen R. A. , Viljanen A.‐M. , Leino T. J. , Härmä M I.
Published: August 2006

We investigated on‐call stress and its consequences among anaesthetists. A questionnaire was sent to all working Finnish anaesthetists (n = 550), with a response rate of 60%. Four categories of on‐call workload and a sum variable of stress symptoms were formed. The anaesthetists had the greatest on‐call workload among Finnish physicians. In our sample, 68% felt stressed during the study. The most important causes of stress were work and combining work with family. The study showed a positive correlation between stress symptoms and on‐call workload (p = 0.009). Moderate burnout was present in 18%vs 45% (p = 0.008) and exhaustion in 32% and 68% (p = 0.015), in the lowest vs highest workload category, respectively. The symptoms were significantly associated with stress, gender, perceived sleep deprivation, suicidal tendencies and sick leave. Being frequently on call correlates with severe stress symptoms and these symptoms are associated with sick leave.
Music therapy in the assessment and treatment of autistic spectrum disorder: clinical application and research evidence
Authors: Wigram T. , Gold C.
Published: August 2006

Background  Children and adolescents with autistic spectrum disorder (ASD) presenting with significant limitations in conventional forms of verbal and non‐verbal communication are found to respond positively to music therapy intervention involving both active, improvizational methods and receptive music therapy approaches. Improvizational musical activity with therapeutic objectives and outcomes has been found to facilitate motivation, communication skills and social interaction, as well as sustaining and developing attention. The structure and predictability found in music assist in reciprocal interaction, from which tolerance, flexibility and social engagement to build relationships emerge, relying on a systematic approach to promote appropriate and meaningful interpersonal responses.

Results  Published reports of the value and effectiveness of music therapy as an intervention for children with ASD range from controlled studies to clinical case reports. Further documentation has emphasized the role music therapy plays in diagnostic and clinical assessment. Music therapy assessment can identify limitations and weaknesses in children, as well as strengths and potentials. Research evidence from a systematic review found two randomized controlled trials that examined short‐term effects of structured music therapy intervention. Significant effects were found in these studies even with extremely small samples, and the findings are important because they demonstrate the potential of the medium of music for autistic children. Case series studies were identified that examined the effects of improvizational music therapy where communicative behaviour, language development, emotional responsiveness, attention span and behavioural control improved over the course of an intervention of improvizational music therapy.
Medical investigation of children with autistic spectrum disorders
Authors: Cass H. , Sekaran D. , Baird G.
Published: August 2006

Few well‐constructed studies have systematically evaluated medical investigation protocols for children with autistic spectrum disorders. This is in large part due to the heterogeneous nature of the population and changing diagnostic frameworks. This review outlines the studies that have directed investigation strategies to date, and discusses how these might be applied in the clinical situation. The importance of listing the conditions that may be present on the basis of the specific clinical presentation, and using a thorough history and examination to generate a pre‐test probability of the target disorders is emphasized if tests are to be useful in directing therapy or broader management approaches.
Development of an Internet‐based real‐time system for monitoring pharmacological interventions in children with neurodevelopmental and neuropsychiatric disorders
Authors: Gringras P. , Santosh P. , Baird G.
Published: August 2006

Few children have a ‘pure’ diagnosis of neuropsychiatric disorders such as attention deficit hyperactivity disorder or autism. Most have complex, overlapping symptoms, and it is often these associated and common comorbidities that cause as much, if not more impairments, than the core symptoms. Prescribing decisions are therefore complex and made on the basis of eliciting a range of agreed ‘target symptoms’. At present, however, there are no agreed systems that allow monitoring of all areas of potential change, and few services are able to monitor symptoms, side effects, impact on family life and individual children’s quality of life systematically. At best many clinics use a plethora of paper‐based standardized questionnaires, based on individual diagnoses. This article describes the development of a novel biomedical informatics system that has been designed to allow parents, professionals and children to use a web‐based, real‐time symptom monitoring system to enable more effective treatments, better pathways of shared care, and more equitable and efficient service delivery for this group of vulnerable children.
Vaccines and the changing epidemiology of autism
Authors: Taylor B.
Published: August 2006

Background  The epidemiology of autism has been rather confusing, with very variable published prevalence figures and no clear incidence data. The cause of autism is unclear; vaccines have been incriminated.

Methods  Literature review and interpretation.

Results  The recorded prevalence of autism has increased considerably in recent years. This reflects greater recognition, with changes in diagnostic practice associated with more trained diagnosticians; broadening of diagnostic criteria to include a spectrum of disorder; a greater willingness by parents and educationalists to accept the label (in part because of entitlement to services); and better recording systems, among other factors. The cause(s) of autism remains unclear. There is a strong genetic component which, along with prenatally determined neuro‐anatomical/biochemical changes, makes any post‐natal ‘cause’ unlikely.

Conclusions  There has (probably) been no real increase in the incidence of autism. There is no scientific evidence that the measles, mumps and rubella (MMR) vaccine or the mercury preservative used in some vaccines plays any part in the aetiology or triggering of autism, even in a subgroup of children with the condition.
Multidisciplinary assessment at a child development centre: do we conform to recommended standards?
Authors: Preece P. M. , Mott J.
Published: August 2006

Background  A proposed standard for the multidisciplinary assessment (MDA) of children with autism has been recently published by the National Autistic Society. This prompted a review of current practice at the child development centre in our local centre, to judge whether we were able to conform to the proposed national standard. The recommendation is that a child should complete a three‐stage assessment process from referral to completion of assessment within 30 weeks, with set times for completion of each stage (6, 7 and 17 weeks respectively). We applied this assessment model to children with a range of neurodevelopment problems, as the process of MDA is the same, irrespective of diagnosis.

Methods  A retrospective analysis of medical and therapy records of all MDAs was carried out between April 2001 and March 2002.

Results  In the 12‐month period studied, 52 MDAs were performed. Delays occurred, as judged by the standard, at all three stages of the assessment process. A total of 42% of children were seen within 6 weeks of initial referral, 37% within a further 7 weeks for specialist assessment, and 37% within a further 17 weeks for completion of MDA. As delays occurred at all stages, the cumulative total showed that only 19% of children completed all three stages within the recommended 30‐week standard. Barriers encountered included waiting times to see professionals, parental non‐attendance and prolonged assessment of complex problems. Some of these factors are outside our control, and on removing these factors the data were re‐analysed. This resulted in a slight improvement to 45%, 48% and 49% for completion of stages 1, 2 and 3 respectively. The major reason for delay remained the service capacity.

Conclusion  In our experience the standards proposed by the National Autistic Society are not practical within present resources. We suggest that a reasonable expectation is to complete all assessments, from first concern to completed MDA, should be carried out within 52 weeks with present levels of resources. Any further improvement will require additional resources to reduce waiting times and increase the capacity.
What services do young children with autism spectrum disorder receive?
Authors: McConachie H. , Robinson G.
Published: August 2006

Background  In recent years, standards of good practice have been set for services to young children with autism spectrum disorders.

Methods  Data were analysed on children’s use of local services during a 2‐year follow‐up of families involved in an evaluation of a group course for parents. Data collection began prior to publication of the standards.

Results  Families’ reported experiences changed over time, but for most did not meet standards suggested: involvement with a multi‐agency team of professionals, having someone who acted as a key worker, and the child accessing 15 h per week of specialist provision.

Conclusion  The development of flexible and responsive services appears to have a long way to go to meet standards set in the Autistic Spectrum Disorders Good Practice Guidance (2002) and the National Autism Plan for Children (2003).
The relationship between the neighbourhood environment and adverse birth outcomes
Authors: Reading Richard
Published: August 2006

.
 
Farley, T.A.,
Mason, K.,
Rice, J.,
Habel, J.D.,
Scribner, R. &
Cohen, D.A.
(
2006
)

,
20
,
188
–
200
.
Stormy weather: race, gene expression, and the science of health disparities
Authors: Spencer Nick
Published: August 2006

.
 
Krieger, N.
(
2005
)

,
95
,
2155
–
2160
.
Hip dislocation in cerebral palsy
Authors: Reading Richard
Published: August 2006

.
 
Pountney, T.,
Green, E.M.
(
2006
)

,
332
,
772
–
775
.
doi:10.1136/bmj.332.7544. 772
.
Department for Education and Skills/Department of Health Good Practice Guidance on the education of children with autistic spectrum disorder
Authors: Jones G.
Published: August 2006

Currently, it is held by many that educational interventions are those most likely to make a significant difference to the prognosis and well‐being of a child with an autistic spectrum disorder (ASD). Yet, decision making about educational interventions and provision in ASD is often based on beliefs, tradition and assumptions, rather than on empirical evidence. This can lead to inappropriate or ineffective provision and can cause confusion and conflict between and within professional groups and parents. Little rigorous research evidence exists to guide decisions for children with ASD. This is true for educational practice generally, and for children with other special educational needs. Practitioners and parents alike are keen for good information on how best to educate children with ASD. It was against this background that the Department for Education and Skills (DfES) and Department of Health (DoH) convened a working group of experienced practitioners and parents to produce the ‘Good Practice Guidance on ASDs’. This paper explores the need for the DfES/DoH Guidance, describes its structure and content and then suggests why research evidence is sparse and how future research might be enhanced to inform practice.
Adipocyte fatty acid binding protein in a Caucasian population: a new marker of metabolic syndrome?
Authors: Stejskal D. , Karpisek M.
Published: August 2006

Background  Adipocyte fatty acid binding protein (A‐FABP) has been suggested as playing an important role in the pathogenesis of metabolic syndrome. The aim of this study was to evaluate serum A‐FABP as a marker of metabolic syndrome and to assess its predictive accuracy in a Caucasian population.

Materials and methods  Anthropometric and serum analyses were performed for body mass index (BMI), waist circumference, A‐FABP, insulin, triglycerides, total cholesterol, high‐density lipoprotein‐cholesterol (HDL‐c), low‐density lipoprotein‐cholesterol (LDL‐c), uric acid, and glucose on 67 non‐obese, healthy subjects and 71 subjects with metabolic syndrome. Quicki‐quantitative insulin sensitivity check index, receiver operating characteristic curve (ROC‐curve) and χ2 analysis were completed.

Results  Compared with healthy controls, subjects with metabolic syndrome had a significantly higher A‐FABP serum level (mean: 42·4 vs. 23·7 µg L−1; P < 0·01). The A‐FABP serum level correlated with fasting levels of insulin (r = 0·34; P < 0·01), glucose (r = 0·21; P = 0·01), triglycerides (r = 0·4; P < 0·01), BMI (r = 0·57; P < 0·01) and waist circumference (r = 0·51; P < 0·01), but negatively with HDL‐c (r = –0·23; P < 0·01) and Quicki (r = –0·32; P < 0·01). The relationship was defined between serum A‐FABP level and metabolic syndrome diagnosis with 40% sensitivity and 99% specificity at A‐FABP level 16·4 µg L−1.

Conclusions  Serum A‐FABP level might be an independent marker of metabolic syndrome in a Caucasian population.
Field evidence for stoichiometric relationships between zooplankton and N and P availability in a shallow calcareous lake
Authors: MCCARTHY VALERIE , DONOHUE IAN , IRVINE KENNETH
Published: August 2006

1. According to stoichiometric theory, zooplankters have a species‐specific elemental composition. Daphniids have a relatively high phosphorus concentration in their tissues and copepods high nitrogen. Daphniids should, therefore, be more sensitive to phosphorus limitation and copepods more sensitive to nitrogen. A 2‐year study of a shallow marl lake in the west of Ireland investigated whether population fluctuations of the two dominant taxa, Daphnia spp. and the calanoid Eudiaptomus gracilis, were associated with the availability of phosphorus and nitrogen.

2. In accordance with stoichiometric predictions, Daphnia and Eudiaptomus reproduction had contrasting relationships with dietary phosphorus and nitrogen availability. Egg production by Daphnia was negatively associated with the ratio of dissolved inorganic nitrogen (DIN) : total phosphorus (TP) and the ratio of light to TP which was used as an indirect index for seston carbon (C) : phosphorus (P). Conversely calanoid egg production had a positive relationship with the DIN : TP ratio and was unrelated to the estimated C : P (light : TP) ratio.

3. Daphnia biomass was not, however, correlated with phosphorus availability, and neither was calanoid biomass correlated with nitrogen. The high ratio of DIN : TP when Daphnia dominated the zooplankton biomass and the low ratio when calanoids dominated, is consistent with Daphnia acting as a sink for phosphorus and calanoids as a sink for nitrogen and suggests consumer‐driven nutrient recycling.
Ontogenetic coupling of growth rate with RNA and P contents in five species of Drosophila
Authors: ELSER J. J. , WATTS T. , BITLER B. , MARKOW T. A.
Published: August 2006

We studied the associations among growth rate, RNA content and P content at ∼12‐h intervals during the larval stage in five species of Drosophilids that specialize on host foods that differ substantially in P content.

Consistent with expectations based on the ‘growth rate hypothesis’ (GRH), within each species there were significant positive correlations between growth rates and RNA and P contents and in each species variation in P content was largely determined by differences in RNA content. However, there was a significant difference among species in how these three parameters were associated with each other, primarily due to differences in the intercept of the relationships rather than in their slopes.

Consistent with the GRH, we also observed positive associations among the average growth rates, RNA contents and P contents of the five species. Furthermore, these differences were broadly consistent with differences in the P content of their host resources: for example, Drosophila falleni, a species that specializes on P‐rich mushrooms, had the highest growth rates and P and RNA contents while D. pachea and D. mettleri, species that specialize in low‐P exudates from necrotic cacti and trees, had the lowest growth rates and P and RNA contents.

While data for additional species are needed, our findings provide further evidence consistent with the GRH and highlight a potential role of P limitation in shaping growth rate evolution in the Drosophilids.
Rarity in the tropics: biogeography and macroecology of the primates
Authors: Harcourt A. H.
Published: August 2006

Aim To describe rarity and elucidate its biology in a tropical mammalian order, the Primates.

Location Africa, Central and South America, Asia, Madagascar.

Methods A review of the literature, with some additional analyses using data from the literature. A variety of definitions of rarity are used in order to describe it and to investigate its biology by correlating the degree of rarity with a variety of biological traits indicative of resource use (e.g. size of annual home range), reproductive rate (e.g. birth interval)and specialization (e.g. number of habitat types used).

Results Few primate taxa occur outside the tropics, and most taxa are rare (small geographical range size or latitudinal extent, low density or both). Latitudinal extent is narrower at lower latitudes in Africa and Asia, but the potential resultant packing of taxa appears not to explain the taxonomic diversity gradient. Whilst primate species do not show the common, positive density by range size relationship, primate genera show a significant shallow slope, and primate families/subfamilies a strongly positive slope. Rare taxa are specialized, but neither use more resources nor breed more slowly than common taxa. The correlation of rarity and specialization is via geographical range: taxa with small ranges, or small ranges for their density, are specialized, but not taxa at low density. Common taxa are generalized because they consist of more differently specialized subtaxa, not because each subtaxon is generalized.

Main conclusions Most primate taxa are rare, in which case most are presumably likely to go extinct. Rare primates are specialized, but do not necessarily use more resources, nor breed more slowly. Specialization as an explanation for rarity appears to work via constriction of range size, not of density. Common primates might be common (large range size) not because subtaxa or individuals are generalized, but because they are composed of more subtaxa. A consequence could be that persistence of even common taxa will depend on conservation of several populations scattered across the taxon's geographical range.
Characterization of immunoglobulin binding by schistosomes
Authors: MCINTOSH R. S. , JONES F. M. , DUNNE D. W. , MCKERROW J. H. , PLEASS R. J.
Published: August 2006

Although controversial, schistosomes are believed to cloak themselves in antibody through non‐specific interactions with the immunoglobulin (Ig) molecule. The acquisition of host Ig by the schistosome may mask its foreign status and/or interfere with Fc‐dependent functions. We report experiments aimed at characterizing the interaction between Ig‐Fc and paramyosin, a schistosome Fc‐receptor previously reported to bind human IgG. We show that certain Ig classes, in particular murine IgG2b and IgG3, are not only able to bind recombinant paramyosin, but also associate with other parasite proteins. The Fc region of IgG contains four hydrophobic patches, two of which are known to interact with distinct molecules: one in the Cγ2–Cγ3 interdomain region bound by protein G, mannose binding lectin (MBL), and the neonatal Fc‐receptor (FcRn), and one at the top of the Cγ2 domain bound by phagocytic FcγRs and C1q. We provisionally discounted the involvement of these regions, since IgG binding by paramyosin did not inhibit FcγR‐mediated NADPH respiratory bursts, and protein G was unable to block IgG binding to paramyosin. Given their apparent low affinity, we postulate hydrogen bonding between reactive residues in a hydrophobic patch at the bottom of the Cγ3 domain and negatively charged Glu or Asp amino acids in paramyosin.