bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of small ice shelves in sea‐level rise
Authors: Dupont T. K. , Alley R. B.
Published: May 2006

Recent observations show marked acceleration and thinning of tributary ice streams following shrinkage or loss of a few of the many small ice shelves that ring Antarctica and Greenland. Our model experiments, which adopt a simplified geometry, show that calving from or partial disintegration of a small ice shelf has more effect on tributary ice streams than does loss of a berg of equal length from a larger ice shelf. Our results, which are consistent with the recent observations, indicate that even small ice shelves can provide important restraint on tributary flow from ice sheets, implying that characterization and modeling of the full range of ice shelves will be required for accurate projection of ice‐sheet changes and their influence on sea level.
A thermal pressurization model for the spontaneous dynamic rupture propagation on a three‐dimensional fault: 2. Traction evolution and dynamic parameters
Authors: Bizzarri A. , Cocco M.
Published: May 2006

We investigate the dynamic traction evolution during the spontaneous propagation of a 3‐D earthquake rupture governed by slip‐weakening or rate‐ and state‐dependent constitutive laws and accounting for thermal pressurization effects. The analytical solutions as well as temperature and pore pressure evolutions are discussed in the companion paper by Bizzarri and Cocco. Our numerical experiments reveal that frictional heating and thermal pressurization modify traction evolution. The breakdown stress drop, the characteristic slip‐weakening distance, and the fracture energy depend on the slipping zone thickness (2w) and hydraulic diffusivity (ω). Thermally activated pore pressure changes caused by frictional heating yield temporal variations of the effective normal stress acting on the fault plane. In the framework of rate‐ and state‐dependent friction, these thermal perturbations modify both the effective normal stress and the friction coefficient. Breakdown stress drop, slip‐weakening distance, and specific fracture energy (J/m2) increase for decreasing values of hydraulic diffusivity and slipping zone thickness. We propose scaling relations to evaluate the effect of w and ω on these physical parameters. We have also investigated the effects of choosing different evolution laws for the state variable. We have performed simulations accounting for the porosity evolution during the breakdown time. Our results point out that thermal pressurization modifies the shape of the slip‐weakening curves. For particular configurations, the traction versus slip curves display a gradual and continuous weakening for increasing slip: in these cases, the definitions of a minimum residual stress and the slip‐weakening distance become meaningless.
Large‐scale modeling of rain fields from a rain cell deterministic model
Authors: Féral Laurent , Sauvageot Henri , Castanet Laurent , Lemorton Joël , Cornet Frédéric , Leconte Katia
Published: May 2006

A methodology to simulate two‐dimensional rain rate fields at large scale (1000 × 1000 km2, the scale of a satellite telecommunication beam or a terrestrial fixed broadband wireless access network) is proposed. It relies on a rain rate field cellular decomposition. At small scale (∼20 × 20 km2), the rain field is split up into its macroscopic components, the rain cells, described by the Hybrid Cell (HYCELL) cellular model. At midscale (∼150 × 150 km2), the rain field results from the conglomeration of rain cells modeled by HYCELL. To account for the rain cell spatial distribution at midscale, the latter is modeled by a doubly aggregative isotropic random walk, the optimal parameterization of which is derived from radar observations at midscale. The extension of the simulation area from the midscale to the large scale (1000 × 1000 km2) requires the modeling of the weather frontal area. The latter is first modeled by a Gaussian field with anisotropic covariance function. The Gaussian field is then turned into a binary field, giving the large‐scale locations over which it is raining. This transformation requires the definition of the rain occupation rate over large‐scale areas. Its probability distribution is determined from observations by the French operational radar network ARAMIS. The coupling with the rain field modeling at midscale is immediate whenever the large‐scale field is split up into midscale subareas. The rain field thus generated accounts for the local CDF at each point, defining a structure spatially correlated at small scale, midscale, and large scale. It is then suggested that this approach be used by system designers to evaluate diversity gain, terrestrial path attenuation, or slant path attenuation for different azimuth and elevation angle directions.
Mean flow, turbulence structure, and bed form superimposition across the ripple‐dune transition
Authors: Fernandez Rocío , Best Jim , López Fabián
Published: May 2006

This paper describes a laboratory study of the dynamics of flow associated with three different stages of bed form amalgamation across the ripple‐dune transition. Measurements of flow velocity were obtained over simplified fixed bed forms, designed to simulate conditions at the ripple:dune transition, using a 2D laser Doppler anemometer. This yielded information detailing the mean velocity field, turbulence statistics, local turbulence production, local deviations from the mean pressure caused by dynamic effects, turbulent kinetic energy and the contributions to the total Reynolds stresses from different coherent turbulent events. The results broadly confirm previous hypotheses that as bed form amalgamation proceeds across the ripple‐dune transition, a superimposed bedstate can induce a series of critical changes to the flow structure, with higher Reynolds stresses being produced near and downstream of flow reattachment. In particular, quadrant 4 events (turbulent flow structures with a downstream velocity greater than average, and directed towards the bed) dominate the vertical turbulent diffusion of longitudinal momentum in near‐bed regions close to the crest of the next downstream ripple, thus providing the potential for increased erosion and sediment transport. These experiments using simple fixed beds also provide support for recent measurements that document increased suspended sediment concentrations across the ripple‐dune transition (Schindler and Robert, 2004, 2005), and that at the transition the largest bed forms are not necessarily those associated with the most intense shear layer activity (Schindler and Robert, 2005). Bed form superimposition and amalgamation may thus significantly alter the mean and turbulent flow field as compared to bed forms without superimposition.
Fructose Metabolism in the Adult Mouse Optic Nerve, A Central White Matter Tract
Authors: Meakin Paul J , Fowler Maxine J , Rathbone Alex J , Allen Lynne M , Ransom Bruce R , Ray David E , Brown Angus M
Published: May 2006

Our recent report that fructose supported the metabolism of some, but not all axons, in the adult mouse optic nerve prompted us to investigate in detail fructose metabolism in this tissue, a typical central white matter tract, as these data imply efficient fructose metabolism in the central nervous system (CNS). In artificial cerebrospinal fluid containing 10 mmol/L glucose or 20 mmol/L fructose, the stimulus-evoked compound action potential (CAP) recorded from the optic nerve consisted of three stable peaks. Replacing 10 mmol/L glucose with 10 mmol/L fructose, however, caused delayed loss of the 1st CAP peak (the 2nd and 3rd CAP peaks were unaffected). Glycogen-derived metabolic substrate(s) temporarily sustained the 1st CAP peak in 10 mmol/L fructose, as depletion of tissue glycogen by a prior period of aglycaemia or high-frequency CAP discharge rendered fructose incapable of supporting the 1st CAP peak. Enzyme assays showed the presence of both hexokinase and fructokinase (both of which can phosphorylate fructose) in the optic nerve. In contrast, only hexokinase was expressed in cerebral cortex. Hexokinase in optic nerve had low affinity and low capacity with fructose as substrate, whereas fructokinase displayed high affinity and high capacity for fructose. These findings suggest an explanation for the curious fact that the fast conducting axons comprising the 1st peak of the CAP are not supported in 10 mmol/L fructose medium; these axons probably do not express fructokinase, a requirement for efficient fructose metabolism.
Local and chain dynamics in miscible polymer blends: A Monte Carlo simulation study
Authors: Luettmer-Strathmann Jutta , Mantina Manjeera
Published: May 2006

Local chain structure and local environment play an important role in the dynamics of polymer chains in miscible blends. In general, the friction coefficients that describe the segmental dynamics of the two components in a blend differ from each other and from those of the pure melts. In this work, we investigate polymer blend dynamics with Monte Carlo simulations of a generalized bond fluctuation model, where differences in the interaction energies between nonbonded nearest neighbors distinguish the two components of a blend. Simulations employing only local moves and respecting a no bond crossing condition were carried out for blends with a range of compositions, densities, and chain lengths. The blends investigated here have long time dynamics in the crossover region between Rouse and entangled behavior. In order to investigate the scaling of the self-diffusion coefficients, characteristic chain lengths Nc are calculated from the packing length of the chains. These are combined with a local mobility μ determined from the acceptance rate and the effective bond length to yield characteristic self-diffusion coefficients Dc=μ∕Nc. We find that the data for both melts and blends collapse onto a common line in a graph of reduced diffusion coefficients D∕Dc as a function of reduced chain length N∕Nc. The composition dependence of dynamic properties is investigated in detail for melts and blends with chains of length N=20 at three different densities. For these blends, we calculate friction coefficients from the local mobilities and consider their composition and pressure dependence. The friction coefficients determined in this way show many of the characteristics observed in experiments on miscible blends.
Multireference configuration interaction study of the electronic states of ZrC
Authors: Denis Pablo A. , Balasubramanian K.
Published: May 2006

The potential energy curves and spectroscopic constants of the ground and 32 low-lying electronic states of ZrC have been studied by employing multireference configuration interaction methods, in conjunction with relativistic effective core potentials and 5s3p3d1f, 3s3p1d basis sets con Zr and C, respectively. We have determined that the ground state is Σ+3. However there are two low-lying Σ+1 states (below 5000cm−1) which strongly interact resulting in avoided crossings. The lowest Σ+1 state corresponds to a combination of 1σ2Xσ21π4 configurations whereas the second is an open shell singlet 1σ22σ13σ11π4. Several avoided crossings were observed, for Π1, Π3, Δ1, Σ+3, and Δ3 states. We have identified Π3 and Π1 lying at 4367 and 5797cm−1, respectively. The results are in good agreement with the recent experimental findings of Rixon et al. [J. Mol. Spectrosc. 228, 554 (2004)], and indicate that the Π3−Σ+3, and Π1−Σ+1, bands located between 16000–19000cm−1 are extremely complex due to near degeneracy of several Π1 and Π3 states. We also have identified a Σ+1 state in the same region that may interfere with the Π1 emission bands. The present results not only shed further light into the spectra of ZrC but also predict yet to be observed systems.
Ab initio based tight-binding molecular dynamics simulation of the sticking and scattering of O2∕Pt(111)
Authors: Groß A. , Eichler A. , Hafner J. , Mehl M. J. , Papaconstantopoulos D. A.
Published: May 2006

The sticking and scattering of O2∕Pt(111) has been studied by tight-binding molecular dynamics simulations based on an ab initio potential energy surface. We focus, in particular, on the sticking probability as a function of the angle of incidence and the energy and angular distributions in scattering. Our simulations provide an explanation for the seemingly paradox experimental findings that adsorption experiments suggest that the O2∕Pt(111) interaction potential should be strongly corrugated while scattering experiments indicate a rather small corrugation. The potential energy surface is indeed strongly corrugated which leads to a pronounced dependence of the sticking probability on the angle of incidence. The scattered O2 molecules, however, experience a rather flat surface due to the fact that they are predominantly scattered at the repulsive tail of the potential.
Cross calibration of AGFA-D7 x-ray film against direct exposure film from 2to8.5keV using laser generated x-rays
Authors: Kyrala George A.
Published: May 2006

Direct exposure film (DEF) is being discontinued. DEF film has been the workhorse in inertial confinement fusion (ICF) research and is used to record x-ray images and spectra. A previous search for a replacement [K. M. Chandler et al., Rev. Sci. Instrum. 76, 113111 (2005)] did not consider AGFA film. We present comparisons using the results of measurements using AGFA-D7 film, XAR, TMG, and Biomax-MS films in the same spectrometer recording a gold spectrum in the 2–4keV range and the iron spectrum in the 5–8.5keV range. AGFA film was found to have some unique properties useful in x-ray spectroscopy and imaging, especially when signal strength is not a concern.
Emerging light fields from liquid crystal microlenses
Authors: Mac Raighne Aaron , Scharf Toralf , McCabe Eithne M.
Published: May 2006

Liquid crystal (LC) microlenses have a variable focal length with a change in applied voltage. These lenses have suitable dimensions and focal length variations for a wide range of applications where the absence of moving parts is favored. In this article we present the three-dimensional imaging of the emerging light fields from these lenses for the first time. This novel technique is evaluated as a measure of the optical performance of the microlenses. It is compared with the results obtained on an interferometer custom built for the investigation of the optical properties of micro-optics. These combined results make this the most detailed investigation of the optical properties of liquid crystal microlenses to date. The results are centered on a microlens with a diameter of 60μm at the lower (0.09) and higher (0.11) numerical apertures achievable with these lenses. In previous studies on LC microlens cells the main area of investigation was the focal length ranges available for particular applications. Images have been taken with these lenses and interference patterns between the extraordinary and ordinary rays propagating through the cells have been presented to show the lensing properties of the cells. However, a detailed examination of their optical properties show that although this type of lenses can produce images at certain voltages they act as diffraction limited lenses only over a short voltage range. It is also shown that the optical properties can be improved by variation of the driving frequency of the applied voltage.
Enhanced performance of an InGaN–GaN light-emitting diode by roughening the undoped-GaN surface and applying a mirror coating to the sapphire substrate
Authors: Peng Wei Chih , Wu YewChung Sermon
Published: May 2006

An InGaN–GaN light-emitting diode (LED) with a roughened undoped-GaN surface and a silver mirror on the sapphire substrate was fabricated through a double transfer method. It was found that, at an injection current of 20mA, its luminance intensity was 100% larger than conventional LEDs. Its output power was 49% larger than conventional LEDs.
Thermal diffusion processes in bulk heterojunction formation for poly-3-hexylthiophene/C60 single heterojunction photovoltaics
Authors: Kim Kyungkon , Liu Jiwen , Carroll David L.
Published: May 2006

We have fabricated bulk heterojunction (BHJ) photovoltaic (PV) devices by thermal annealing of poly-3-hexylthiophene (P3HT)/C60 single heterojunction (HJ) PV devices at near the melting point of P3HT. The BHJ PV devices exhibited an increased efficiency of 12 times compared with single HJs. We found that the annealing of HJ devices produces an interpenetrated network of interfaces between the P3HT and C60 layers. This plays a major role in carrier separation and mobility enhancement. Also the formation of crystalline C60 domains, concurrent with polymer crystallinity, contributes to an increase in the overall external conversion efficiency. Surprisingly, the heterojunction morphology, as inferred through device performance, strongly depends on the thermal gradient across the film.
Implantation temperature dependence of Si activation in AlGaN
Authors: Irokawa Y. , Ishiguro O. , Kachi T. , Pearton S. J. , Ren F.
Published: May 2006

Si + ion implantation at a total dose of 1.0×1015cm−2 and multiple ion energies in the range of 30–190keV into Al0.13Ga0.87N layers on sapphire substrates for n-type doping was carried out at substrate temperatures ranging from −196to700°C, followed by annealing at 1150–1400°C for 5min. The activation efficiency at fixed annealing temperature (1250°C) was highest (∼50%) for room temperature implantation and degraded significantly for elevated temperature implantation. The effective Si donor ionization energy decreased with increasing annealing temperature, which may be related to the Mott transition that creates degenerate layers as the activation percentage increased. The minimum sheet resistance obtained was ∼100Ω∕sq after annealing room temperature implants at 1350–1400°C.
Charge and spin storage in self-organized quantum dots
Authors: Wieczorek W. , Warming T. , Geller M. , Bimberg D. , Cirlin G. E. , Zhukov A. E. , Ustinov V. M.
Published: May 2006

We demonstrate optical charging of spectrally selected subensembles of self-organized quantum dots with single charge carriers. In spectral hole burning experiments negative and positive trions are observed, representing quantum dots charged with single electrons and holes. By circularly polarized excitation in an applied magnetic field we are able to address the spin of single electrons. A spin flip of the electron is observed after excitation in the upper Zeeman level.
Room-temperature transient carrier transport in germanium single-hole/electron transistors
Authors: Liao W. M. , Li P. W. , Kuo David M. T. , Lai W. T.
Published: May 2006

We report the experimental observation of transient carrier transports at room temperature in a Ge quantum-dot (QD) single-hole transistor (SHT) and single-electron transistor (SET). In addition to room-temperature Coulomb oscillations, hysteresis effects have been observed in the steady-state tunneling current of a Ge-SHT and a Ge-SET as gate voltage is swept in a loop. Time-dependent tunneling current of a Ge-SHT and a Ge-SET displays clear oscillatory or staircase behavior at a constant voltage stress condition, which indicates transient charging/discharging of electrons and holes via a Ge QD due to substantial quantum mechanics effect.
Remote angular displacement sensor based on Faraday effect: Experiment and modeling
Authors: Park C. M. , Melikhov Y. , Lee S. J.
Published: May 2006

Recently, we have reported a magneto-optic angular displacement (MOAD) sensor where both the incident and reflected laser beams pass through a magneto-optic (MO) film. In this letter, we report a modified MOAD sensor where only a reflected laser beam passes through the MO film. With the modified configuration, the modified MOAD sensor is a truly remote sensor such that the MO film can be located close to the detector and far from the sample. Furthermore, the modified sensor system can measure angular displacements with an improved resolution of 1×10−3deg, which is ten times better than that previously reported.
A New Protocol to Synthesize Di(indolyl)pyrazolyl Methanes Using H2PtCl6 as a Catalyst in Ionic Liquid: Synthesis of Novel 3-[1H-indol-3-yl(3-phenyl-1H-pyrazol-4-yl)methyl]-1H-indoles
Authors: Murugan Rajendran , Reddy Boreddy S. R.
Published: May 2006

Biologically important di(indolyl)pyrazolyl methanes and their derivatives were synthesized in excellent yields by the electrophilic substitution of indole with pyrazolyl aldehydes catalyzed by H2PtCl6 in ionic liquid.
One-Dimensional Ag(I) Organometallic Coordination Polymers Generated from a Fulvene-Based Ligand
Authors: Wang Peng , Ma Jian-Ping , Huang Ru-Qi , Dong Yu-Bin
Published: May 2006

A new fulvene-based ligand L was synthesized and its coordination chemistry with Ag(i) ion has been investigated. Two novel Ag(i) polymeric complexes, [Ag2L2∙5.5(C6H6)]SbF6 (1) and [AgL∙2.5(C6H6)]SbF6 (2), were obtained by combination of L with AgSbF6 in one-pot reaction. X-Ray single-crystal analysis revealed that both 1 and 2 crystallize in triclinic system P1. In 1 and 2, the ligand L adopts a trans-conformation to bind the Ag(i) centres into a one-dimensional twin-chain structure through either Ag–O coordination or π–π interactions.
Retention of (4,4) Connectivity in the Absence of π…π Interactions in a Cadmium tris-Dicyanamide Compound
Authors: Biswas Moumita , Batten Stuart R. , Jensen Paul , Mitra Samiran
Published: May 2006

An anionic cadmium tris-dicyanamide compound (Et4N)[Cd(N(CN)2)3]·3/4H2O 1 has been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, X-ray powder diffraction, and X-ray crystallography. The anions form extended sheets with retention of (4,4) connectivity in the absence of π···π interactions within the cation layers, and with octahedral geometry about individual CdII ions.
π-Extended Alkylidenecycloproparenes
Authors: Halton Brian , Cooney Mark J.
Published: May 2006

Reaction of benzene-1,4-dicarboxaldehyde with anion 6 derived from 1,1-bis(trimethylsilyl)cyclopropa[b]naphthalene 1 gives 4-(methylidene-1H-cyclopropanaphthalenyl)benzaldehyde 7 as a minor product and 1,4-bis(methylidene-1H-cyclopropanaphthalenyl)benzene 8 as the major product of the reaction. With 4-{(E)-2-[4-(dimethylamino)phenyl]ethenyl}benzaldehyde 14, this same anion affords the stilbene-substituted π-extended (1-arylmethylidene)cyclopropanaphthalene 15 as a sparingly soluble orange-red powder.
Influence of Compressed Carbon Dioxide on the Oxidation of Cyclohexane with Hydrogen Peroxide in Acetic Acid
Authors: Gao Liang , Jiang Tao , Han Buxing , Zong Baoning , Zhang Xiaoxin , Zhang Jicheng
Published: May 2006

The oxidation of cyclohexane with H2O2 in a compressed CO2/acetic acid binary system was studied at 60.0 and 80.0°C, at pressures up to 18 MPa, and with the zeolite TS-1 as catalyst. The phase behaviour of the reaction system was also observed. There are three fluid phases in the reaction system at lower pressure but two at higher pressures. In the three-phase region the yields of the products, cyclohexanol and cyclohexanone, increase considerably with increasing pressure and reaches a maximum near the phase-separating pressure. CO2 can thus enhance the reaction effectively. However, the effect of pressure on the yield is very limited after the transition to a two-phase system.
The Potentials of the Third Generation of Flow Injection Analysis for Nutrient Monitoring and Fractionation Analysis
Authors: Miró Manuel , Hansen Elo Harald , Buanuam Janya
Published: May 2006

Environmental Context.Miniaturization, portability and automation are three major issues in environmental chemistry research that can be fully accomplished by exploitation of flow-injection based approaches. Actually, the fast response of flow injection makes the analytical data available in real-time, which is especially desirable for environmental monitoring. Although initially devised for liquid-phase assays, flow systems have also proven suitable for automated handling of solid samples, which opens new avenues for the performance of fractionation analysis (e.g., sequential extraction methods) in an automated dynamic fashion.
Abstract.In the present communication, the third generation of flow injection analysis, the so-called micro sequential-injection Laboratory-on-Valve (μSI-LOV), is presented as a miniaturized, automated approach for on-line monitoring of nutrients in different environmental compartments as effected under enclosed and strictly controlled conditions. Special emphasis is placed on coupling μSI-LOV on-line with a recently developed microcolumn to perform dynamic fractionation schemes for ascertaining the availability of phosphorus forms in solid substrates for biota uptake under simulated environmental scenarios.
Modelling internal solitary waves on the Australian North West Shelf
Authors: Grimshaw Roger , Pelinovsky Efim , Stepanyants Yury , Talipova Tatiana
Published: May 2006

The transformation of the non-linear internal tide and the consequent development of internal solitary waves on the Australian North West Shelf is studied numerically in the framework of the generalised rotation-modified Korteweg–de Vries equation. This model contains both non-linearity (quadratic and cubic), the Coriolis effect, depth variation and horizontal variability of the density stratification. The simulation results demonstrate that a wide variety of non-linear wave shapes can be explained by the synergetic action of non-linearity and the variability of the hydrology along the wave path.
Observations of bottom intensification of temperature and velocity fluctuations induced by oblique tidal interactions with a slope
Authors: Antenucci Jason P. , Ivey Gregory N.
Published: May 2006

Long-term measurements of temperature and velocity collected at six depths in 302 m of water off the North West Cape of Western Australia (21°37′35″S, 113°56′11″E) revealed several periods of extreme near-bed currents. The dominant forcing at the site is the M2 tide, with energy levels generally decreasing as the bottom is approached. There is, however, a dramatic change in the energy distribution for all frequencies in excess of the M4 tidal frequency between 80 and 10 m above the seabed. Waves in this frequency bandwidth are critical to the local bottom slope and show a strong linear internal wave signature; however, they do not appear to conform with linear internal wave reflection theory. Dissipation estimates reveal energetic motions with dissipation rates of ~10−5 m2 s−3. Superimposed on this ambient state, three energetic events with duration varying between 8 and 24 h can also be detected. These are characterised by large increases in energy levels in the high-frequency range, and peak speeds varying from 0.59 m s−1 to 1.87 m s−1. These events appear to be driven by direct local energy inputs at high frequencies.
Teachers' developing ‘practical theories’ of the contribution of information and communication technologies to subject teaching and learning: an analysis of cases from English secondary schools
Authors: Deaney Rosemary , Ruthven Kenneth , Hennessy Sara
Published: May 2006

This article examines teachers' ‘practical theories’ concerning the contribution of information and communications technology (ICT) to teaching and learning, as they are elaborated and refined in action. The study arose from a collaborative programme of 10 small‐scale projects through which participating teacher‐researchers aimed to develop a range of pedagogic strategies involving the use of computer‐based ICTs within their subject areas (Classics, English, Geography, History, Science and Design Technology). Within‐ and cross‐case analyses drew on multiple sources of data and characterised teachers' initial statements of practical theory in terms of five key themes: broadening classroom resources and reference; enhancing working processes and products; fostering more independent pupil activity; mediating subject thinking and learning; and improving pupil motivation towards lessons. Three cases are presented to illustrate how teachers developed their ideas in action, and issues that prompted teachers across cases to adapt their approaches are discussed.
Effects of irradiation using a radioisotope-filled balloon on tissue hyperplasia caused by stent placement in a canine urethral model
Authors: Shin Ji Hoon , Song Ho-Young , Moon Dae Hyuk , Oh Seung-Jun , Kim Jung-Sun , Kim Eun-Hee , Kim Tae-Hyung , Woo Chul-Woong , Kim Eun-Young , Park Seong Ho
Published: May 2006

Purpose: To evaluate 20 Gy and 40 Gy of intraluminal beta-irradiation using a 188Re-7mercaptoacetyltriglycine (MAG3)-filled balloon catheter to reduce tissue hyperplasia caused by covered stent placement for 12 weeks of follow-up in a canine urethral model.

Material and Methods: Ten dogs underwent 188Re-MAG3-filled balloon dilatation immediately after stent placement; 20 Gy at 1-mm tissue depth in group I ( n = 5) and 40 Gy in group II ( n = 5), whereas 5 dogs (group III) underwent conventional balloon dilatation only.

Results: There were no significant differences among the three groups for percentage diameter of stenosis, although this was highest in group III. There was a tendency toward lower mean thickness of the epithelial layer and the papillary projection for out-stent area, and thickness of the papillary projection and degree of inflammatory cells for in-stent area in groups I and II compared with group III. Thickness of the papillary projection in out-stent area was significantly different among the three groups ( P = 0.031). It was significantly less thick in group I than in group III ( P<0.05), whereas group II was not significantly different from group III.

Conclusion:188Re-MAG3-filled balloon dilatation has the potential to reduce tissue hyperplasia after 12 weeks of follow-up in a canine urethral model. The use of 20 Gy compared to 40 Gy did not show significant differences.
Determining the level of the dural sac tip: magnetic resonance imaging in an adult population
Authors: Binokay F. , Akgul E. , Bicakci K. , Soyupak S. , Aksungur E. , Sertdemir Y.
Published: May 2006

Purpose: To determine the variation in the location of the dural sac (DS) in a living adult population and to correlate this position with age and sex.

Material and Methods: T2-weighted, midline, sagittal, spin-echo magnetic resonance imaging (MRI) studies of 743 patients were assessed to identify the tip of the DS. This location was recorded in relation to the upper, middle, or lower third of the adjacent vertebral body or the adjacent intervertebral disk.

Results: Frequency distribution for levels of termination of the DS on MRI demonstrated that the end of the DS was usually located at the upper one-third of S2 (25.2%). The mean level in females was also the upper one-third of S2 (26.5%) and in males the lower one-third of S2 (24.1%). The overall mean DS position was mostly at the upper one-third of S2. No significant differences in DS position were seen between male and female patients or with increasing age.

Conclusion: It is important to know the possible range for the termination level of the DS when performing caudal anesthesia and craniospinal irradiation in some clinical situations. The distribution of DS location in a large adult population was shown to range from the L5-S1 intervertebral disk to the upper third of S3 vertebrae.
Buprenorphine Treatment: A Three‐Year Prospective Study in Opioid‐Addicted Patients of a Public Out‐Patient Addiction Center in Milan
Authors: Cozzolino Edoardo , Guglielmino Livia , Vigezzi Pierluigi , Marzorati Paolo , Silenzio Rosella , De Chiara Margherita , Corrado Filomena , Cocchi Laura
Published: May 2006

The data shown here were collected with an open label prospective design from March 2001 to February 2004 while conducting routine recruitment and therapy of heroin‐addicted patients. All of the data collected demonstrate the safety and efficacy of buprenorphine therapy and different characteristics observed in buprenorphine patients versus methadone patients.
Immunology and Homeopathy. 3. Experimental Studies on Animal Models
Authors: Bellavite Paolo , Ortolani Riccardo , Conforti Anita
Published: May 2006

A search of the literature and the experiments carried out by the authors of this review show that there are a number of animal models where the effect of homeopathic dilutions or the principles of homeopathic medicine have been tested. The results relate to the immunostimulation by ultralow doses of antigens, the immunological models of the ‘simile’, the regulation of acute or chronic inflammatory processes and the use of homeopathic medicines in farming. The models utilized by different research groups are extremely etherogeneous and differ as the test medicines, the dilutions and the outcomes are concerned. Some experimental lines, particularly those utilizing mice models of immunomodulation and anti‐inflammatory effects of homeopathic complex formulations, give support to a real effect of homeopathic high dilutions in animals, but often these data are of preliminary nature and have not been independently replicated. The evidence emerging from animal models is supporting the traditional ‘simile’ rule, according to which ultralow doses of compounds, that in high doses are pathogenic, may have paradoxically a protective or curative effect. Despite a few encouraging observational studies, the effectiveness of the homeopathic prevention or therapy of infections in veterinary medicine is not sufficiently supported by randomized and controlled trials.
Decaying wood is a sodium source for mountain gorillas
Authors: Rothman Jessica M , Van Soest Peter J , Pell Alice N
Published: May 2006

Like several other non-human primates, mountain gorillas (
Gorilla beringei beringei
) in Bwindi Impenetrable National Park, Uganda consume decaying wood, an interesting but puzzling behaviour. This wood has little obvious nutritional value; it is low in protein and sugar, and high in lignin compared to other foods. We collected pieces of wood eaten and avoided by gorillas, and other foods consumed by gorillas, and measured their sodium content. Wood was substantially higher in sodium than other dietary items, and wood pieces from stumps eaten contained more sodium than those that were avoided. Wood represented only 3.9% of the wet weight food intake of gorillas, but contributed over 95% of dietary sodium, leading us to conclude that decaying wood is an important sodium source for Bwindi gorillas. Because sodium has been leached from the weathered soils characteristic of the subhumid and humid tropics, and because terrestrial plants generally do not require sodium, tropical herbivores, including gorillas, often encounter problems locating the sodium essential for their well-being. Decaying wood is an unexpected sodium source.
Maternal developmental stress reduces reproductive success of female offspring in zebra finches
Authors: Naguib Marc , Nemitz Andrea , Gil Diego
Published: May 2006

Environmental factors play a key role in the expression of phenotypic traits and life-history decisions, specifically when they act during early development. In birds, brood size is a main environmental factor affecting development. Experimental manipulation of brood sizes can result in reduced offspring condition, indicating that developmental deficits in enlarged broods have consequences within the affected generation. Yet, it is unclear whether stress during early development can have fitness consequences projecting into the next generation. To study such trans-generational fitness effects, we bred female zebra finches,Taeniopygia guttata, whose mothers had been raised in different experimental brood sizes. We found that adult females were increasingly smaller with increasing experimental brood size in which their mother had been raised. Furthermore, reproductive success at hatching and fledging covaried negatively with the experimental brood size in which their mothers were raised. These results illustrate that early developmental stress can have long-lasting effects affecting reproductive success of future generations. Such trans-generational effects can be life-history responses adapted to environmental conditions experienced early in life.
Craniofacial malformations: intrinsic vs extrinsic neural crest cell defects in Treacher Collins and 22q11 deletion syndromes
Authors: Walker MB , Trainor PA
Published: May 2006

The craniofacial complex is anatomically the most sophisticated part of the body. It houses all the major sensory organ systems and its origins are synonymous with vertebrate evolution. Of fundamental importance to craniofacial development is a specialized population of stem and progenitor cells, known as the neural crest, which generate the majority of the bone, cartilage, connective and peripheral nerve tissue in the head. Approximately one third of all congenital abnormalities exhibit craniofacial malformations and consequently, most craniofacial anomalies are considered to arise through primary defects in neural crest cell development. Recent advances however, have challenged this classical dogma, underscoring the influence of tissues with which the neural crest cells interact as the primary origin of patterning defects in craniofacial morphogenesis. In this review we discuss these neural crest cell interactions with mesoderm, endoderm and ectoderm in the head in the context of a better understanding of craniofacial malformations such as in Treacher Collins and 22q11 deletion syndromes.
Genetic diversity in European pigs utilizing amplified fragment length polymorphism markers
Authors: SanCristobal M. , Chevalet C. , Peleman J. , Heuven H. , Brugmans B. , Van Schriek M. , Joosten R. , Rattink A. P. , Harlizius B. , Groenen M. A. M. , Amigues Y. , Boscher M.‐Y. , Russell G. , Law A. , Davoli R. , Russo V. , Dèsautés C. , Alderson L. , Fimland E. , Bagga M. , Delgado J. V. , Vega‐Pla J. L. , Martinez A. M. , Ramos M. , Glodek P. , Meyer J. N. , Gandini G. , Matassino D. , Siggens K. , Laval G. , Archibald A. , Milan D. , Hammond K. , Cardellino R. , Haley C. , Plastow G.
Published: May 2006

The use of DNA markers to evaluate genetic diversity is an important component of the management of animal genetic resources. The Food and Agriculture Organisation of the United Nations (FAO) has published a list of recommended microsatellite markers for such studies; however, other markers are potential alternatives. This paper describes results obtained with a set of amplified fragment length polymorphism (AFLP) markers as part of a genetic diversity study of European pig breeds that also utilized microsatellite markers. Data from 148 AFLP markers genotyped across samples from 58 European and one Chinese breed were analysed. The results were compared with previous analyses of data from 50 microsatellite markers genotyped on the same animals. The AFLP markers had an average within‐breed heterozygosity of 0.124 but there was wide variation, with individual markers being monomorphic in 3–98% of the populations. The biallelic and dominant nature of AFLP markers creates a challenge for their use in genetic diversity studies as each individual marker contains limited information and AFLPs only provide indirect estimates of the allelic frequencies that are needed to estimate genetic distances. Nonetheless, AFLP marker‐based characterization of genetic distances was consistent with expectations based on breed and regional distributions and produced a similar pattern to that obtained with microsatellites. Thus, data from AFLP markers can be combined with microsatellite data for measuring genetic diversity.
Conceptions of pain among Somali women
Authors: Finnström Berit , Söderhamn Olle
Published: May 2006

Aim. This paper reports a study of a group of Somali mothers' views on pain, the causes of pain, pain behaviour and pain treatment concerning themselves and their family members.

Background. Both the meaning of pain and pain behaviour are associated with values in a patient's social and cultural context. Culture also provides models for how to treat and relieve pain. Several studies report a lack of cultural sensitivity and competence among healthcare professionals, resulting in lower quality of and less access to health care and pain treatment for minority groups. However, the majority of the scientific literature on pain and culture concerns adults in the United States of America.

Method. Focused conversational interviews were carried out with a convenience sample of nine Somalia women living in Sweden in order to describe and explore their conceptions of pain. Qualitative content analysis was conducted through meaning condensation. The data were collected in 2002–2003.

Findings. The women expressed a number of different ideas about definitions and causes of pain. Somalis, especially men, are expected to be stoic about pain. The women had different strategies for communicating about and relieving pain. Children from the ages of 6–8 years upwards were expected to control their pain expression. Respondents used both formal and informal care to relieve pain. For some of the women, consulting a psychologist was not a culturally acceptable way of seeking pain relief.

Conclusions. Nurses must strive for increased cultural competence and explore ways to make healthcare services sensitive to culturally diverse groups. Nurses have an educational role in educating parents and children about pain and the importance of sufficient pain relief. All healthcare providers should be aware of their own cultural values and the risk of stereotyping people.
Functioning and subjective health among stroke survivors after discharge from hospital
Authors: Pajalic Zada , Karlsson Siv , Westergren Albert
Published: May 2006

Aim.  This paper reports a study exploring functioning (functions, activities and participation) and subjective health among stroke survivors 6 months after discharge from hospital. A further aim was to investigate patterns of functions and activities, and associations between functioning and subjective health.

Background.  Nurses tend to emphasize functional and activity outcomes and rarely look to people's participation in their social world. By integrating individual and social contextual factors in their assessments, nurses will have a powerful tool to broaden their outlook. The International Classification of Functioning, Disability and Health can be used as a framework for understanding the consequences of stroke. Studies are needed, however to make the International Classification of Functioning operational for practical use.

Methods.  A cross‐sectional and explorative design was used using structured interviews and assessments with a number of scales with 89 stroke survivors 6 months after their hospital stay. The measures used were Personal Activities of Daily Living, including cognitive ability, transfer, dressing, bathing, energy to eat, ingestion, swallowing, going to the toilet, faecal continence, and urinary continence; and Instrumental Activities of Daily Living, including washing clothes, cooking, cleaning, transport and shopping. Factor analysis was performed for functions and activities and the final solution had an explained variance of 70%. The data were collected during autumn 2003 and spring 2004.

Findings.  Close associations (rs > 0·5) were found between Activities of Daily Living in relation to participation and subjective physical health.

Conclusion.  Existing Activities of Daily Living scales were expanded and found to relate to a participation scale and a subjective health scale. Using these scales in nursing care has the potential to correct current bias towards functions and activities by broadening the focus to include the social as well as the physical.
Is the humanistic view of the nurse role still alive – in spite of an academic education?
Authors: Björkström Monica E. , Johansson Inger S. , Athlin Elsy E.
Published: May 2006

Aim.  This paper is a report of a study exploring what ‘being a good nurse’ means by following nursing students during their pre‐registration education and for some years after graduation.

Background.  There have been few studies focusing on the nurse role in the transition from student to experienced nurse. Studies with a qualitative design, in particular, are limited in number.

Methods.  A longitudinal survey design was adopted, using an open‐ended questionnaire at the beginning of education (n = 164), just before graduation (n = 123), and 3–5 years after graduation (n = 77). The participants were students in the nursing programme at a Swedish university. The data were collected during the period 1993–2002. Latent and manifest content analyses were used.

Findings.  Four categories were identified in the data. ‘To do good for others’, with the sub‐category ‘to care for others’, was most frequent over time and quite stable. The category ‘to be competent and skilled’ was frequent and increased over time. ‘To have professional courage and pride’ and ‘to seek professional development’ were mentioned to lesser extent and showed a slight increase over time. The meaning of being a good nurse grew in complexity over time and informants’ professional awareness seemed to increase, especially concerning ‘to be competent and skilled’.

Conclusion.  Attention needs to be paid both to nursing education and practice. Clinical supervision given by nurses with Master's degrees is suggested in order to convey positive attitudes towards nursing development and research into practice. Further studies are needed to compare what ‘a good nurse’ means to graduate nurses and how they actually behave when performing good nursing care.
Community nurses’ health promotion work with older people
Authors: Runciman Phyllis , Watson Hazel , McIntosh Jean , Tolson Debbie
Published: May 2006

Aims.  This paper reports a study describing community nurses’ health promotion work with older people aged 50 years and above, and exploring particular health promotion initiatives for older people that would have transferability potential.

Background.  With the ageing of populations worldwide, community nurses in primary healthcare settings have a key contribution to make to the health improvement agenda for older people, yet little is known of the extent of this aspect of their work.

Methods.  Questionnaires were sent to 1062 community nurses in six Scottish National Health Service Boards – public health nurses/health visitors, district nurses, general practice nurses, community psychiatric and learning disability nurses and combined duty nurses; 373 (35%) responded, 30 of whom were interviewed by telephone. The data were collected in 2003–2004.

Findings.  Findings confirmed the wide scope of health promotion, much of which may be embedded and unrecognized. Creative group work showed promise in achieving heath gain for older people, and a range of partnership approaches – interdisciplinary, multidisciplinary and interagency – was evident. Theoretical input and project opportunities within educational programmes had been a catalyst for health promotion initiatives in practice. However, evidence of audit, evaluation, and active involvement of older people in planning health promotion was limited. Funding of health promotion initiatives was vital to sustainability.

Conclusion.  There is merit in making the health promotion work of community nurses more visible through audit and systematic evaluation; promoting the active involvement of older people; strengthening partnership working; and further raising the profile of health in later life within undergraduate and postgraduate community nursing programmes.