bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulse-train control of branching processes: Elimination of background and intruder state population
Authors: Seidl Markus , Etinski Mihajlo , Uiberacker Christoph , Jakubetz Werner
Published: December 2008

The authors introduce and describe pulse train control (PTC) of population branching in strongly coupled processes as a novel control tool for the separation of competing multiphoton processes. Control strategies are presented based on the different responses of processes with different photonicities and/or different frequency detunings to the pulse-to-pulse time delay and the pulse-to-pulse phase shift in pulse trains. The control efficiency is further enhanced by the property of pulse trains that complete population transfer can be obtained over an extended frequency range that replaces the resonance frequency of simple pulses. The possibility to freely tune the frequency assists the separation of the competing processes and reduces the number of subpulses required for full control. As a sample application, PTC of leaking multiphoton resonances is demonstrated by numerical simulations. In model systems exhibiting sizable background (intruder) state population if excited with single pulses, PTC leading to complete accumulation of population in the target state and elimination of background population is readily achieved. The analysis of the results reveals different mechanisms of control and provides clues on the mechanisms of the leaking process itself. In an alternative setup, pulse trains can be used as a phase-sensitive tool for level switching. By changing only the pulse-to-pulse phase shift of a train with otherwise unchanged parameters, population can be transferred to any of two different target states in a near-quantitative manner.
Laser assisted heating of extreme ultraviolet-emitting z-pinch plasmas
Authors: Wieneke Stephan , Brückner Stephan , Viöl Wolfgang
Published: December 2008

A low-current and low-compression z-pinch nitrogen plasma is heated up by means of a short laser pulse. Spectra are taken in the extreme ultraviolet spectral range from 11 to 18 nm to estimate the heating effect. Without additional laser heating the initial plasma conditions are ne≈1017 cm−3 and Te≈11 eV. The additional laser heating causes an increase in the electron temperature of about a factor of 5 to Te≈57 eV, whereas the electron density nearly remains at the initial value. The experimentally determined values are compared to the results obtained by means of simulations and are in fairly good agreement.
Experimental observation of intermodal dispersion in photonic crystal directional couplers
Authors: Cuesta-Soto Francisco , Martínez Alejandro , Martí Javier
Published: December 2008

The intrinsic multimode nature of a directional coupler responsible for its functionality leads to intermodal dispersion. In this work, the authors experimentally demonstrate at microwave frequencies that the energy components of a pulse coupled to each of the supermodes of the photonic crystal directional coupler travel at different velocities. An intermodal dispersion of 5 ns/m is measured, which is in good agreement with the theoretical results. This value is more than two orders of magnitude higher than that reported from conventional two-core fiber couplers.
Stability of the polydomain state in epitaxial ferroelectric PbTiO3 films
Authors: Bartasyte A. , Dkhil B. , Kreisel J. , Chevreul J. , Chaix-Pluchery O. , Rapenne-Homand L. , Jimenez C. , Abrutis A. , Weiss F.
Published: December 2008

Phase transitions and domain state transformations in a 250 nm thick PbTiO3/SrTiO3 film with c/a/c/a domain structure were investigated by temperature-dependent x-ray diffraction and Raman spectroscopy. Both techniques provide evidence that the film remains tetragonal up to 650 °C, while the bulk sample becomes cubic at 490 °C. Small anomalies in the width of both Bragg peaks and in Raman modes suggest a subtle structural rearrangement around 500 °C.
Current distribution effects in organic sexithiophene field effect transistors investigated by lock-in thermography: Mobility evaluation issues
Authors: Riccio M. , Irace A. , Breglio G. , Rossi L. , Barra M. , Di Girolamo F. V. , Cassinese A.
Published: December 2008

In this Letter, a lock-in thermography technique has been used to investigate the actual current distribution profile in the active channel region of organic field effect transistors. The high accuracy of the setup shows an evidence of nonuniformity in the current flow over the device area. The physical origin of this experimental occurrence is tentatively ascribed to a not uniform contact resistance distribution along the channel width or to inhomogeneities in the interface traps distribution. The subsequent implications on the carrier mobility evaluation are discussed too.
Analytical solution for charge-carrier injection into an insulating layer in the drift diffusion approximation
Authors: Shashkin V. I. , Vostokov N. V.
Published: December 2008

Using a drift-diffusion approximation, we obtain an analytical solution to the problem of charge-carrier injection into an insulating i layer of finite thickness with account of self-consistent boundary conditions. The main assumption is that the self-doping of the i layer is neglected. The solution makes it possible to calculate the potential, electric field, and current-voltage characteristics of a variety of structures such as metal-i layer-n+ (or p+) semiconductor, metal-i layer-metal, and n+(p+)-i-n+(p+) structures. The solution admits a generalization for structures having heterobarriers at the interface of the semiconductor layers. The proposed approach allows for the contact phenomena and bulk effects related to that the current is space charge-limited in the i layer. The solution is valid for both the limiting cases and the transient regimes.
Relevant correlation between electrical and magnetic properties for p-type InP:Zn implanted with Mn (10 at. %)
Authors: Kim Jin Soak , Kim Eun Kyu , Shon Yoon , Lee Sejoon
Published: December 2008

A relevant correlation between magnetic properties and Mn-related deep level states for the Mn-implanted p-type InMnP:Zn layers annealed at 400–600 °C was investigated. For the 600 °C-annealed sample, the portion of deep level transient spectroscopy signals corresponding to Mn-related states was observed to significantly increase while that related to charge-trapping centers observed for 400 and 500 °C-annealed samples drastically decreased. The sample showed the improved ferromagnetic properties compared with other samples. These results are considered as originating from the effective incorporation of Mn ions into the InP:Zn host lattice with recovering the crystallinity after thermal annealing.
Formative time of breakdown modeled for the ignition of air and n-butane mixtures using effective ionization coefficients
Authors: Kudryavtsev A. A. , Popugaev S. D. , Demidov V. I. , Adams S. F. , Jiao C. Q.
Published: December 2008

It is shown that simulations of ignition by electric arc discharge in n-butane and air mixtures have interesting features, which deviate from results obtained by simple extension of calculations based on methanelike fuels. In particular, it is demonstrated that lowering the temperature of the n-butane-air mixture before ignition under certain conditions will actually decrease the ignition stage time as well as the required electric field.
Time-resolved photoluminescence of isoelectronic traps in ZnSe1−xTex semiconductor alloys
Authors: Lin Y. C. , Chou W. C. , Fan W. C. , Ku J. T. , Ke F. K. , Wang W. J. , Yang S. L. , Chen W. K. , Chang W. H. , Chia C. H.
Published: December 2008

Kohlrausch’s stretched exponential law correlates well with the photoluminescence (PL) decay profiles of ZnSe1−xTex. As the Te concentration increases, the stretching exponent β initially declines and then monotonically increases. This result can be understood using the hopping-transport and energy transfer model. The increase in the number of isoelectronic Te localized traps can reduce the PL decay rate and increase the linewidth, whereas the hybridization of the Te localized states with the valence-band edge states causes a reduction in both the lifetime and linewidth.
Two-dimensional photonic crystals with germanium on insulator obtained by a condensation method
Authors: Ngo Thi-Phuong , El Kurdi M. , Checoury Xavier , Boucaud Philippe , Damlencourt J. F. , Kermarrec O. , Bensahel D.
Published: December 2008

Germanium on insulator on silicon substrates can be obtained by the growth of a SiGe layer on silicon on insulator followed by a condensation at high temperature and a Ge epitaxial growth. We show that these substrates can be used for photonic devices. Two-dimensional photonic crystals with defect cavities have been fabricated. The emission at room temperature of condensed germanium can be spectrally controlled by varying the lattice parameter of the photonic crystals. Resonant emission is obtained between 1400 and 1700nm when modifying the lattice periodicity between 400 and 480nm for L3 cavities in a triangular lattice. Quality factors of 540 are obtained for the fundamental mode of the L3 cavity around 1600nm. The experimental radiation pattern of the defect cavities is compared to the one calculated by a finite-difference time-domain method. A specificity of the germanium-on-insulator photonic crystals is that the optical sources are distributed within the whole material, by opposition to photonic crystals with a single quantum dot layer internal source.
A Demographic Model for Small Area Population Projections: An Application to the Census Metropolitan Area of Hamilton in Ontario, Canada
Authors: Kanaroglou Pavlos S , Maoh Hanna F , Newbold Bruce , Scott Darren M , Paez Antonio
Published: December 2008

This paper reports on the development of a demographic model capable of projecting the spatial distribution of population by age and sex for small areas such as census tracts. The proposed modeling framework makes use of two components: the Rogers multiregional population projection model and the aggregate spatial multinomial logit (ASMNL) model. The Rogers model utilizes cohort vital statistics on fertility, mortality, and migration to project the progression of population by age and sex at the regional level, while the ASMNL model extends the capabilities of the Rogers model enabling it to provide population estimates at a finer spatial scale. The model is applied to the Hamilton Census Metropolitan Area in Canada. Our simulation tests highlight the robustness of the proposed modeling approach in utilizing small area characteristics and regional vital statistics to perform small area population projections.
Jobs Deficits, Neighbourhood Effects, and Ethnic Penalties: The Geography of Ethnic-Labour-Market Inequality
Authors: Simpson Ludi , Purdam Kingsley , Tajar Abdelouahid , Pritchard John , Dorling Danny
Published: December 2008

The reduction of inequalities in the labour market both between ethnic groups and between local areas indicates improved access to jobs because a diverse workforce is socially and economically desirable. We construct and analyse a unique evidence base of the labour-market circumstances at the neighbourhood level. We use the 2001 Census data for England and Wales to examine the impact of age, sex, birthplace, and educational qualifications on the employment of ethnic minorities nationally. We compute locally expected employment on the basis of these relationships and local characteristics, and compare it with locally observed employment. Our analysis demonstrates that 1.1 million new jobs are required to bring every ethnic group in every locality up to the average England and Wales employment rate. National ethnic-group differences account for most of this local job deficit; local variation in demographic composition and human capital account for a smaller proportion of the jobs deficit. Residual neighbourhood effects have both a geography common to each ethnic group (for example, a gradient of higher jobs deficits in the Midlands, the North of England, and Wales), and some group-specific characteristics (for example, more favourable outcomes for Pakistani and Bangladeshi groups in the North than might have been expected). The findings and approach allow targeting employment policies geographically and thematically. In addition, the on-line evidence base ( http://asp.ccsr.ac.uk/dwp ) is a public resource which can be used to investigate local outcomes and to prioritise remedial action.
Gendered, Material, and Partial Knowledges: A Feminist Critique of Neighborhood-Level Indicator Systems
Authors: Derickson Kate Driscoll
Published: December 2008

As researchers and community-based organizations increasingly move toward a more ‘holistic approach’ to addressing urban problems, the use of neighborhood-level social indicator systems as a tool to inform resident activism is becoming common practice. In this paper, I use a feminist theoretical framework to critically assess the epistemology and methodology of current practices in the use and development of neighborhood-level indicator systems. Using the National Neighborhood Indicators Partnership as a framework, I critique the practices of using quantitative, spatial statistics to ‘democratize information’ within the feminist theoretical debates surrounding the production of knowledge, the use of quantitative methods, difference across gender, essentialism versus antiessentialism, and the discursive production of gender. In so doing, I demonstrate the importance of a feminist theoretical and practical perspective in informing the future development of urban neighborhood-level indicator systems.
Arsenic accumulation, biotransformation and localisation in bertha armyworm moths
Authors: Andrahennadi Ruwandi , Pickering Ingrid J.
Published: December 2008

Environmental context. Insects play an important role in the impact of environmental pollutants such as arsenic. They may accumulate arsenic to high levels, potentially modifying its chemical form, which affects the insects’ toxicity to predators such as fish and birds. Here we use synchrotron X-ray techniques to determine the distribution and chemical form of arsenic in larva, pupa and adult of the bertha armyworm moth. Abstract. Insects are important in bioaccumulation and dispersal of environmental contaminants such as arsenic, and biotransformation of arsenic to various chemical forms directly impacts its toxicity to insects and to their predators. In a model study, the toxic effects and biotransformation of arsenic were examined in larvae, pupae and adults of bertha armyworm moth (Mamestra configurata Walker) (Lepidoptera: Noctuidae). A synthetic diet containing 100 μM arsenate caused reduced larval survival and increased pupal stage duration but no effect on pupal weight or larval stage duration. Synchrotron X-ray absorption spectroscopy (XAS) showed that larvae biotransformed dietary arsenate to yield predominantly trivalent arsenic coordinated with three aliphatic sulfurs, modelled as AsIII-tris-glutathione. Similar species were found in pupae and adults. XAS imaging with micro X-ray fluorescence imaging revealed highly localised arsenic species, and zinc and copper within the gut. The implication of these arsenic species in the diets of predators is discussed.
Modification of sediment - water solute exchange by sediment-capping materials: effects on O2 and pH
Authors: Vopel K. , Gibbs M. , Hickey C. W. , Quinn J.
Published: December 2008

The release of phosphorus from sediments can stimulate algal blooms in eutrophic water bodies worldwide. One technique to reduce this release involves capping the sediment with millimetre-thick layers of chemically active materials such as aluminium hydroxide floc (alum), and the mineral-based products Phoslock and modified zeolite. The effects of this technique on transport and reaction of diagenetically important sediment compounds other than phosphorus are unknown. The present study used microelectrodes to measure the apparent gas diffusivity of capping layers derived from different doses of these capping materials and their effects on pore water pH and dissolved molecular oxygen. The apparent O2 diffusivity of alum capping layers (1.58 × 10–5 cm2 s–1) was constant with depth and higher than that of mineral-based capping layers (~1.15 × 10–5 cm2 s–1 and decreasing with depth in the capping layer). The capping materials raised the depth of the oxic–anoxic interface and associated pH minimum and altered the sediment O2 consumption as functions of the capping-layer thickness and apparent diffusivity. Modified zeolite layers decreased pore water pH slightly (0.3–0.5 units); alum layers decreased pH by 1–2.2 units. It is proposed that capping layers derived from doses >200 g m–2 can alter benthic process rates and solute fluxes.
Periphyton communities in New Zealand streams impacted by acid mine drainage
Authors: Bray Jonathan P. , Broady Paul A. , Niyogi Dev K. , Harding Jon S.
Published: December 2008

Discharges from historic and current coal mines frequently generate waters low in pH (<3), high in heavy metals (e.g. Fe, Al) and cover streambeds in metal precipitates. The present study investigated periphyton communities at 52 stream sites on the West Coast, South Island, New Zealand, representing a range of impacts from acid mine drainage (AMD). Taxonomic richness was negatively related to acidity and metal oxides and biomass was negatively correlated with metal oxides, but positively related to acidity. Streams with low pH (<3.5) had low periphyton richness (14 taxa across all sites) and were dominated by Klebsormidium acidophilum, Navicula cincta and Euglena mutabilis. As pH increased, so did taxonomic richness while community dominance decreased and community composition became more variable. Canonical correspondence analyses of algal assemblages revealed patterns influenced by pH. These findings indicate that streams affected by AMD possess a predictable assemblage composition of algal species that can tolerate the extreme water chemistry and substrate conditions. The predictability of algal communities declines with decreasing stress, as other abiotic and biotic factors become increasingly more important.
Selenium bioaccumulation and biomagnification in Lake Wallace, New South Wales, Australia
Authors: Jasonsmith J. F. , Maher W. , Roach A.C. , Krikowa F.
Published: December 2008

Selenium concentrations were measured in water, sediments and organisms inhabiting a freshwater coal power station cooling reservoir. Se concentrations found were: water, 1.9 ± 2 μg L–1; sediment, 7 ± 1 μg g–1; phytoplankton, 3.4 μg g–1; zooplankton, 5.3 μg g–1; epiphytic algae, 1.3 ± 0.2 μg g–1; benthic algae, 8 ± 2 μg g–1; macrophyte leaves, 2.7–2.8 μg g–1; macrophyte roots, 0.5–6.5 μg g–1; detritus, 10 μg g–1; Oligochaeta, 11 μg g–1; Corbiculidae, 1.1 μg g–1; Insects, 3.7–8.3 μg g–1; Gastropoda, 3.2 μg g–1; Crustacea, 3.1–6 μg g–1; whole fish, 2.2–13 μg g–1; and fish liver, 134–314 μg g–1. Bioconcentration factors were similar to those found in aquatic ecosystems with comparable Se concentrations in the water column. A food web was constructed with four main food chains (phytoplankton, epiphytic algae, benthic algae and sediment/detrital), with fish fed from multiple pathways. Biomagnification only occurs along food chains for flathead gudgeons and rainbow trout. Se concentrations in food sources were above the 3 μg g–1 dietary Se level considered to induce teratogenesis in fish spawning. Flathead gudgeons were found to be suffering teratogenesis and rainbow trout showed no evidence of teratogenesis.
Modeling the temporal evolution of the spindle assembly checkpoint and role of Aurora B kinase
Authors: Mistry Hitesh B. , MacCallum David E. , Jackson Robert C. , Chaplain Mark A. J. , Davidson Fordyce A.
Published: December 2008

Faithful separation of chromosomes prior to cell division at mitosis is a highly regulated process. One family of serine/threonine kinases that plays a central role in regulation is the Aurora family. Aurora B plays a role in the spindle assembly checkpoint, in part, by destabilizing the localization of BubR1 and Mad2 at centrosomes and responds to changes in tension caused by aberrant microtubule kinetochore attachments. Aurora B is overexpressed in a subset of cancers and is required for mitosis, making it an attractive anticancer target. Here, we use mathematical modeling to extend a current model of the spindle assembly checkpoint to incorporate all signaling kinetochores within a cell rather than just one and the role of Aurora B within the resulting model. We find that the current model of the spindle assembly checkpoint is robust to variation in its key diffusion-limited parameters. Furthermore, when Aurora B inhibition is considered within the model, for a certain range of inhibitor concentrations, a prolonged prometaphase/metaphase is observed. This level of inhibitor concentrations has not yet been studied experimentally, to the authors' best knowledge. Therefore, experimental verification of the results discussed here could provide a deeper understanding of how kinetochores and Aurora B cooperate in the spindle assembly checkpoint.
Promises of hydropedology.
Authors: Pachepsky Y. , Giménez D. , Lilly A. , Nemes A.
Published: December 2008

Integrative studies are needed as the response to mounting environmental challenges. The new discipline - hydropedology - has been defined as an intertwined branch of soil science and hydrology that encompasses the multiscale basis and applied research of interactive and hydrologic processes and their properties in the unsaturated zone. This review focuses on the relationship between soil structure and soil hydraulic functions at different scales, which is the distinct focus of hydropedology that makes it a desirable development for its parent disciplines. Status and perspectives are reviewed for revealing relationships between hydrologic functions of soils and soil structure at the aggregate/ped scale, the horizon/pedon scale, the field/hillslope scale and the watershed/basin scale. Transcending scales can be achieved by acknowledging that relationships between soil structure and hydrologic functioning at a particular scale are controlled by such relationships at a finer scale and greatly influenced by those at a coarser scale. Addressing soil hydrologic functioning at societally important scales can be achieved by applying data fusion, pedotransfer relationships, and concurrent use of models. Hydropedology emerges as the logical consequence of the progress in science and as the timely response to society's needs.
Maternal input and lexical development: the case of deaf pre‐schoolers
Authors: Farran Lama K. , Lederberg Amy R. , Jackson Lori A.
Published: December 2008

Background: Mothers facilitate their young hearing children's word learning by making reference explicit for novel words through physical designation (e.g., with deictic gestures) and by isolating words in simple syntactic frames. As children's language skills develop, such modifications decrease. Less is known about hearing mothers' support to their language‐delayed deaf children.

Aims: The current study investigated whether hearing mothers tailored their input to suit their deaf children's word‐learning ability as well as their children's word knowledge.

Methods & Procedures: Maternal input to 25 oral deaf children was examined. Word‐learning ability was assessed in an experimental task that tested the children's ability to novel map (i.e., infer that a novel word refers to a novel object without physical designation). Word knowledge was assessed by maternal report.

Outcome & Results: Mothers whose children did not infer word meaning through novel mapping made meaning more explicit than mothers of children who could learn through novel mapping. Specifically, these mothers were more likely to designate referents physically and use simple syntax. For all children, mothers were more likely to make the meaning of novel words more transparent than familiar words.

Conclusions & Implications: The results indicate that hearing mothers were sensitive to the needs of their deaf children. This sensitivity was to children's word knowledge. Mothers seemed aware of what words were in their children's lexicon. Mothers did not rely on their children's ability to use novel mapping, even for the linguistically advanced children.
The Novel Epididymis-Specific Beta-Galactosidase-Like Gene Glb1l4 Is Essential in Epididymal Development and Sperm Maturation in Rats
Authors: Zhen Wei , Li Peng , He Bin , Guo Juyuan , Zhang Yong-Lian
Published: December 2008

We describe a novel epididymis-specific cDNA named Glb1l4, which was isolated from rat epididymis by differential display of mRNAs. Glb1l4 cDNA contains 2607 nucleotides and encodes a 637-amino acid protein with 50% similarity to mouse beta-galactosidase. The gene is located on chromosome 8q13, spanning 21 exons. Northern blot analysis reveals that Glb1l4 is specifically expressed in the caput region of epididymis and upregulated by androgen. A specific polyclonal antiserum against the N-terminal peptide of GLB1L4 has been produced. Western blot analysis and immunohistochemistry assay reveal that GLB1L4 is specifically expressed in the principal cells of the caput epididymis. Interestingly, its expression peaks at Postnatal Day 45 in mRNA level and at Postnatal Day 60 in protein level while the epididymis column cells undergo differentiation. Moreover, within this very period this secretory protein is confined inside the cell with a change of subcellular distribution pattern, which implies its important roles in the cell differentiation process. Only after the epididymal epithelium differentiation is completed and the spermatozoa enter the epididymal lumen is the GLB1L4 secreted into the luminal fluid and bound on the sperm head. Our results suggest that GLB1L4 may play various roles in principal cell differentiation and sperm maturation.
Associations between the transtheoretical processes of change, nicotine dependence and adolescent smokers' transition through the stages of change
Authors: Kleinjan Marloes , Brug Johannes , Van Den Eijnden Regina J. J. M. , Vermulst Ad A. , Van Zundert Rinka M. P. , Engels Rutger C. M. E.
Published: December 2008

Aims  To examine the significance of the transtheoretical processes of change in predicting transition through the stages of change in adolescent smokers, as well as the relative role of nicotine dependence in predicting stage transitions.

Design  In grades 9 and 10, adolescents' stage of change, the use of processes of change and nicotine dependence were assessed (T1). Stage transitions were assessed 1 year later (T2). Response rate was 73.2%.

Setting  Twenty‐five secondary schools throughout the Netherlands participated in the present study.

Participants  Respondents were 721 adolescents who were classified as smokers at T1 and consequently completed the paper‐and‐pencil questionnaire at T2.

Measurements  Stages of change and processes of change were assessed according to the original transtheoretical measures. Nicotine dependence was measured using a newly developed multi‐dimensional scale consisting of 11 items.

Findings  Few associations were found between the processes of change and stage transitions. Nicotine dependence contributed significantly to the explanation of adolescents' transition from preparation to action, after adjustment for processes of change. No evidence for a moderating effect of nicotine dependence in the relation between the processes of change and stage transitions was found.

Conclusions  Processes of change do not seem significant in explaining adolescents' stage transitions. As an alternative for promoting the use of the processes of change for intervention purposes in adolescents, it might be more useful to focus on treating nicotine dependence.
Ex vivo study on root canal instrumentation of two rotary nickel–titanium systems in comparison to stainless steel hand instruments
Authors: Vaudt J. , Bitter K. , Neumann K. , Kielbassa A. M.
Published: December 2008

Aim  To investigate instrumentation time, working safety and the shaping ability of two rotary nickel–titanium (NiTi) systems (Alpha System and ProTaper Universal) in comparison to stainless steel hand instruments.

Methodology  A total of 45 mesial root canals of extracted human mandibular molars were selected. On the basis of the degree of curvature the matched teeth were allocated randomly into three groups of 15 teeth each. In group 1 root canals were prepared to size 30 using a standardized manual preparation technique; in group 2 and 3 rotary NiTi instruments were used following the manufacturers’ instructions. Instrumentation time and procedural errors were recorded. With the aid of pre‐ and postoperative radiographs, apical straightening of the canal curvature was determined. Photographs of the coronal, middle and apical cross‐sections of the pre‐ and postoperative canals were taken, and superimposed using a standard software. Based on these composite images the portion of uninstrumented canal walls was evaluated.

Results  Active instrumentation time of the Alpha System was significantly reduced compared with ProTaper Universal and hand instrumentation (P < 0.05; anova). No instrument fractures occurred in any of the groups. The Alpha System revealed significantly less apical straightening compared with the other instruments (P < 0.05; Mann–Whitney U test). In the apical cross‐sections Alpha System resulted in significantly less uninstrumented canal walls compared with stainless steel files (P < 0.05; chi‐squared test).

Conclusion  Despite the demonstrated differences between the systems, an apical straightening effect could not be prevented; areas of uninstrumented root canal wall were left in all regions using the various systems.
Disease mongering: expanding the boundaries of treatable disease
Authors: Doran E. , Henry D.
Published: December 2008

Traditionally, the promotional activities of medical industries have been product specific. In recent years, however, there have been examples where companies have worked through partnerships, which have included clinicians, to expand the boundaries of treatable disorders. The main motivation appears to be to increase sales of commercial products. The term ‘disease mongering’ has been applied to these activities. Whereas some disease awareness programmes may bring benefits in the form of improved recognition and management of disorders, the presence of strong commercial interests probably distorts the traditional processes by which treatable diseases have been defined. This can result in individual patients being exposed to potential harms, with little expectation of benefit and will place an unwarranted burden on the publicly funded health‐care system. None of this can happen without the collaboration of the medical profession that needs to be aware of the risks of becoming involved in commercially supported ‘consensus’ groups that are reviewing the definition and management of diseases.
Every voice matters: evaluating residential provision at a special school
Authors: Hallett Fiona , Hallett Graham , McAteer Mary
Published: December 2008

This article, written by Fiona Hallett, pathway leader for the inclusion and special educational needs masters programmes at Edge Hill University, Graham Hallett, senior lecturer for special educational needs and inclusion at the University of Cumbria, and Mary McAteer, programme leader for an M level professional development programme at Edge Hill University, presents the findings of an evaluative report on the review of residential provision at an identified community special school. Within this review, a consultation was undertaken with parents and pupils to assist in shaping policy and practice, and the main focus of this study is to evaluate the effectiveness of that process. By using an evaluative case study approach, it was hoped to document the chronological narrative of the consultation process and offer recommendations as to the effectiveness of participation in this instance. The authors conclude that the qualitative features seen by pupils and parents as having the greatest value suggest a need for high quality, accessible social care, rather than for curricular led, educational residential provision. Fiona Hallett, Graham Hallett and Mary McAteer's critique of the consultation process raises issues relating to the complexities of eliciting a valid pupil perspective. In addition, the authors express concerns about the general conduct of the review regarding bias, validity and the absence of staff voice.
The effects of speech and language therapy intervention on children with pragmatic language impairments in mainstream school
Authors: Adams Catherine , Lloyd Julian
Published: December 2008

In this article, Catherine Adams, clinical senior lecturer in speech and language therapy at the University of Manchester, and Julian Lloyd, senior lecturer in psychology at Newman College, Birmingham, describe the implementation and effects of an intensive programme of speech and language therapy for children who have pragmatic language impairment (PLI) attending mainstream education in the north west of England. An intervention which focused on aspects of pragmatic language such as conversation, inference and narrative was developed. Six children who have PLI (mean age=7;10 years), all with a Statement of special educational needs, participated in a single case study series in which they each received 20 sessions of the speech and language therapy programme in their own school. Guidance and specific training was provided for learning support assistants and classroom teachers. Despite showing heterogeneity in their initial profiles of impairment, progress in conversation skills was seen in all six children and some significant changes in language test performance were found. These findings suggest that intensive speech and language therapy intervention has the potential to produce generalis‐able gains in language and communication skills in children who have PLI and indicate appropriate outcome measures for future effectiveness studies.
Potential Role of Enhanced Cytokinemia and Plasma Inhibitor on the Decreased Activity of Plasma ADAMTS13 in Patients With Alcoholic Hepatitis: Relationship to Endotoxemia
Authors: Ishikawa Masatoshi , Uemura Masahito , Matsuyama Tomomi , Matsumoto Masanori , Ishizashi Hiromichi , Kato Seiji , Morioka Chie , Fujimoto Masao , Kojima Hideyuki , Yoshiji Hitoshi , Tsujimoto Tatsuhiro , Takimura Chikara , Fujimura Yoshihiro , Fukui Hiroshi
Published: December 2008

Background:  Deficiency of ADAMTS13 (adisintegrin‐like and metalloproteinase with thrombospondin type‐1 motifs 13) results in an increase in unusually large von Willebrand factor multimer (UL‐VWFM) of the plasma and finally causes microcirculatory disturbance. Our previous study demonstrated that the imbalance of increased UL‐VWFM over decreased ADAMTS13 activity may contribute to the development of multiorgan failure in patients with alcoholic hepatitis (AH). The aim of this study was to explore the potential mechanism to reduce the activity of plasma ADAMTS13.

Methods:  Plasma cytokine levels including interleukin (IL)‐6, IL‐8, and tumor necrosis factor‐α (TNF‐α), plasma endotoxin concentration, and the plasma inhibitor against ADAMTS13 were determined together with ADAMTS13 activity, VWF antigen (VWF:Ag), and UL‐VWFM in 24 patients with AH and 5 patients with severe alcoholic hepatitis (SAH).

Results:  The concentrations of IL‐6, IL‐8, and TNF‐α on admission were significantly higher in patients with SAH than in those with AH and controls. The ADAMTS13 activity concomitantly decreased, and the VWF:Ag progressively elevated with increasing concentrations of these cytokines from normal range to over 100 pg/ml. Plasma endotoxin concentration was markedly higher in patients with SAH (mean 52.3 pg/ml) and AH (21.7 pg/ml) than in controls (7.9 pg/ml). The endotoxin concentration inversely correlated with ADAMTS13 activity and was higher in patients with UL‐VWFM than those without. The inhibitor was detected in 4 patients with SAH (0.9 to 2.1 BU/ml) and 6 patients with AH (0.5 to 1.6 BU/ml). Patients with the inhibitor showed lower functional liver capacity, higher endotoxin concentration, and marked inflammatory signs than those without. At the recovery stage, the ADAMTS13 activity increased to normal range, the VWF:Ag decreased, and the UL‐VWFM disappeared with the decrease in the concentrations of cytokines and endotoxin, and the disappearance of the inhibitor.

Conclusion:  Decreased ADAMTS13 activity and increased VWF:Ag could be induced not only by pro‐inflammatory cytokinemia, but also by its inhibitor, both of which may be closely related to enhanced endotoxemia in patients with AH and SAH.
Exogenous IL‐15 in Combination With IL‐15Rα Rescues Natural Killer Cells From Apoptosis Induced by Chronic Alcohol Consumption
Authors: Zhang Hui , Meadows Gary G.
Published: December 2008

Background:  Chronic alcohol consumption reduces the percentage and number of peripheral natural killer (NK) cells in mice and in humans. The underlying mechanism for these changes is only partly known. We recently found that chronic alcohol consumption inhibits NK cell release from the bone marrow (BM) and that this is associated with a decrease in splenic NK cells. The number of peripheral NK cells is tightly controlled by homeostatic proliferation. It is not known whether this mechanism is initiated in response to the reduction in splenic NK cells, or if so, why the steady state levels of NK cells are not restored.

Methods:  To examine this mechanism, female C57BL/6 mice were given 20% w/v alcohol in the drinking water for 3 months. NK cell proliferation and apoptosis were determined before and after treatment with IL‐15 alone or combined with its alpha receptor.

Results:  Chronic alcohol consumption invoked homeostatic proliferation of splenic NK cells in an attempt to return NK cells to normal levels; however, this did not happen due to enhanced apoptosis of NK cells relative to proliferation. Chronic alcohol consumption decreased IL‐15 producing cells in the spleen but not in the BM. The numbers of NK cells in the alcohol‐consuming mice returned to normal levels in the spleen and were higher than normal in the BM after 2 daily injections of IL‐15; however, the enhanced rate of apoptosis due to alcohol consumption was not decreased in the spleen or BM. Combined IL‐15 and IL‐15Rα treatment decreased apoptosis of NK cells from alcohol‐consuming mice to levels similar to untreated water‐drinking mice and greatly increased the percentage and number of NK cells in both the spleen and BM.

Conclusion:  Chronic alcohol consumption causes a self‐unrecoverable loss of NK cells in the spleen by compromising NK cell release from the BM and enhancing splenic NK cell apoptosis that can be reversed with IL‐15/IL‐15Rα treatment.
Sensitivity and Tolerance to the Hypnotic and Ataxic Effects of Ethanol in Adolescent and Adult C57BL/6J and DBA/2J Mice
Authors: Linsenbardt David N. , Moore Eileen M. , Gross Carly D. , Goldfarb Karen J. , Blackman Laverne C. , Boehm II Stephen L.
Published: December 2008

Background:  There is considerable research examining differences in adolescent and adult sensitivity and tolerance to ethanol related behavioral phenotypes. However, the available published data has almost exclusively assessed these behaviors in outbred rats. The present study was conducted using the alcohol preferring inbred mouse strain C57BL/6J (B6) and the alcohol nonpreferring inbred mouse strain DBA/2J (D2) to determine if differences in the sedative and ataxic effects of ethanol exist between adolescents and adults, and to determine whether there are any genetic influences involved therein.

Methods:  Adolescent and adult mice of each sex and genotype were given intraperitoneal (i.p.) injections of ethanol (1.5, 1.75, or 4.0 g/kg) or saline and assessed for the loss of righting reflex (LORR) or hind footslips on the balance beam apparatus. These animals were then tested for the development of tolerance to these behaviors on subsequent days.

Results:  Despite evident pharmacokinetic differences, D2 adolescents were found to be relatively less sensitive to ethanol’s hypnotic actions than their adult D2 counterparts. Adolescent and adult B6 animals did not differ. Furthermore, although adult animals appeared to develop significantly greater degrees of tolerance to ethanol‐induced hypnosis compared with adolescents, these effects were likely in part related to differences in ethanol absorption/metabolism across time. Taking into account pharmacokinetic differences and the overall poor performance of male adults, adolescent animals were found to be equally if not more sensitive to the motor incoordinating (ataxic) effects of ethanol. Overall, tolerance to these effects varied by age and genotype but appeared to be related to changes in ethanol pharmacokinetics rather than strict behavioral sensitivity.

Conclusion:  The current work suggests that adolescent B6 and D2 inbred mice exhibit ontogenetic differences in sensitivity to ethanol’s hypnotic and ataxic effects. Importantly, in some cases age differences emerge as a function of differential ethanol pharmacokinetics. These results extend the current literature examining this critical developmental period in mice and illustrate the benefits of comparing ethanol related developmental differences in different genetic mouse populations.
Global–Local Interference is Related to Callosal Compromise in Alcoholism: A Behavior‐DTI Association Study
Authors: Müller‐Oehring Eva M. , Schulte Tilman , Fama Rosemary , Pfefferbaum Adolf , Sullivan Edith V.
Published: December 2008

Background: Visuospatial ability is a multifactorial process commonly impaired in chronic alcoholism. Identification of which features of visuospatial processing are affected and which are spared in alcoholism, however, has not been clearly determined. We used a global–local paradigm to assess component processes of visuospatial ability and MR diffusion tensor imaging (DTI) to examine whether alcoholism‐related microstructural degradation of the corpus callosum contributes to disruption of selective lateralized visuospatial and attention processes.

Methods: A hierarchical letter paradigm was devised, where large global letters were composed of small local letters. The task required identification of target letters among distractors presented at global, local, both, or neither level. Attention was either selectively directed to global or local levels or divided between levels. Participants were 18 detoxified chronic alcoholics and 22 age‐matched healthy controls. DTI provided quantitative assessment of the integrity of corpus callosal white matter microstructure.

Results: Alcoholics generally had longer reaction times than controls but obtained similar accuracy scores. Both groups processed local targets faster than global targets and showed interference from targets at the unattended level. Alcoholics exhibited moderate compromise in selectively attending to the global level when the global stimuli were composed of local targets. Such local interference was less with longer abstinence. Callosal microstructural integrity compromise predicted degree of interference from stimulus incongruency in the alcoholic group. This relationship was not observed for lateral or third ventricular volumes, which are measures of nonspecific cortical volume deficits.

Conclusion: Global–local feature perception was generally spared in abstinent chronic alcoholics, but impairments were observed when directing attention to global features and when global and local information interfered at stimulus or response levels. Furthermore, the interference‐callosal integrity relationship in alcoholics indicates that compromised visuospatial functions include those requiring bilateral integration of information.
The Unique Adaptation of the Life Cycle of the Coelomic Gregarine Diplauxis hatti to its Host Perinereis cultrifera (Annelida, Polychaeta): an Experimental and Ultrastructural Study
Authors: PRENSIER GERARD , DUBREMETZ JEAN‐FRANCOIS , SCHREVEL JOSEPH
Published: December 2008

ABSTRACT. The coelomic gregarine Diplauxis hatti exhibits a unique adaptation of its life cycle to its polychaete host Perinereis cultrifera. Experimental and ultrastructural observations on natural populations from the English Channel showed that release of parasite spores is concomitant with the polychaete spawning. As the development of P. cultrifera is direct, the notochete larva ingest parts of the jelly coat covered with numerous sporocysts of D. hatti during hatching. Transepithelial migration of the sporozoites takes place in the gut of three‐ or four‐segment notochete larvae and syzygies of about 20 μm are observed in the coelom. Growth of these young syzygies is slow: after 18–24 mo they reach only 60–70 μm. They exhibit active pendular movements. In the English Channel, female and male gametogenesis of P. cultrifera begins at 19 mo and 2 yr, respectively; the somatic transformations (epitoky) in the last 4 mo of their 3‐year life. During epitoky, the syzygies undergo an impressive growth and reach 700–800 μm within a few weeks. A shift from pendular to active peristaltic motility is observed when the syzygies reach 200–250 μm. When gamogony occurs, syncytial nuclear divisions are initiated and cellularization produces hundred to thousands of male and female gametes of similar size. The male gametes exhibit a flagellum with 3+0 axoneme. The mixing of the gametes (“danse des gametes”) and fertilization are observed during 4–5 h. Zygotes differentiate sporoblasts with eight sporozoites. The sporozoites exhibit the canonical structure of Apicomplexa, a polarized cell with micronemes and rhoptries.
First Account of Apochlorotic Diatoms from Mangrove Waters in Florida
Authors: BLACKBURN MICHELE V. , HANNAH FIONA , ROGERSON ANDREW
Published: December 2008

ABSTRACT. From January to December 2004, monthly samples were collected from the mangrove salt marsh of J.U. Lloyd State Park, Florida, to examine the spatial and temporal distributions of heterotrophic diatoms in this subtropical region. Four non‐pigmented (i.e. apochlorotic), heterotrophic diatom morphotypes were isolated from mangrove neuston and plankton sites. Colorless diatoms were numerically significant in neuston during the fall and winter months and counts peaked at 174 × 103 cells/L in December. Heterotrophic diatoms were most prevalent in mangrove plankton in October and averaged 55.5 × 103 cells/L. Valve morphology was detailed for mangrove morphotypes (I, II, V, and VI). However, only one type (I) was named with confidence (Nitzschia leucosigma). The other three types failed to conform closely to published diagnostic features suggesting that either characters are more variable than accepted or these types were new species. Growth responses to changes in salinity and irradiance were detailed in the laboratory. All morphotypes were euryhaline, tolerating salinities between 10‰ and 40‰; N. leucosigma was most salt tolerant and grew from 10‰ to 60‰. Maximum growth was achieved between 20‰ and 40‰. Growth was not significantly different for heterotrophic diatoms during light and dark treatments or for diatoms grown with or without bacteria.