A comparison of theoretical line intensity ratios for Ni XII with extreme ultraviolet observations from the JET tokamak

Recent R-matrix calculations of electron impact excitation rates in Ni XII are used to derive the emission line ratios R-1 = I(154.17 Angstrom)/I(152.15 Angstrom), R-2 = I(152.95 Angstrom)/I(152.15 Angstrom) and R-3 = 1(160.55 Angstrom)/I(152.15 Angstrom). This is the first time (to our knowledge) that theoretical emission line ratios have been calculated for this ion. The ratios are found to be insensitive to changes in the adopted electron density (N-e) when N-e greater than or equal to 5 x 10(11) cm(-3), typical of laboratory plasmas. However, they do vary with electron temperature (T-e), with for example R-1 and R-3 changing by factors of 1.3 and 1.8, respectively, between T-e = 10(5) and 10(6) K. A comparison of the theoretical line ratios with measurements from the Joint European Tents (JET) tokamak reveals very good agreement between theory and observation for R-1, with an average discrepancy of only 7%. Agreement between the calculated and experimental ratios for R-2 and R-3 is less satisfactory, with average differences of 30 and 33%, respectively. These probably arise from errors in the JET instrument calibration curve. However, the discrepancies are smaller than the uncertainties in the R-2 and R-3 measurements. Our results, in particular for R-1, provide experimental support for the accuracy of the Ni XIII line ratio calculations, and hence for the atomic data adopted in their derivation.

Chitosan nanoparticle as protein delivery carrier - Systematic examination of fabrication conditions for efficient loading and release

Chitosan nanoparticles fabricated via different preparation protocols have been in recent years widely studied as carriers for therapeutic proteins and genes with varying degree of effectiveness and drawbacks. This work seeks to further explore the polyionic coacervation fabrication process, and associated processing conditions under which protein encapsulation and subsequent release can be systematically and predictably manipulated so as to obtain desired effectiveness. BSA was used as a model protein which was encapsulated by either incorporation or incubation method, using the polyanion tripolyphosphate (TPP) as the coacervation crosslink agent to form chitosan-BSA-TPP nanoparticles. The BSA-loaded chitosan-TPP nanoparticles were characterized for particle size, morphology, zeta potential, BSA encapsulation efficiency, and subsequent release kinetics, which were found predominantly dependent on the factors of chitosan molecular weight, chitosan concentration, BSA loading concentration, and chitosan/TPP mass ratio. The BSA loaded nanoparticles prepared under varying conditions were in the size range of 200-580 nm, and exhibit a high positive zeta potential. Detailed sequential time frame TEM imaging of morphological change of the BSA loaded particles showed a swelling and particle degradation process. Initial burst released due to surface protein desorption and diffusion from sublayers did not relate directly to change of particle size and shape, which was eminently apparent only after 6 h. It is also notable that later stage particle degradation and disintegration did not yield a substantial follow-on release, as the remaining protein molecules, with adaptable 3-D conformation, could be tightly bound and entangled with the cationic chitosan chains. In general, this study demonstrated that the polyionic coacervation process for fabricating protein loaded chitosan nanoparticles offers simple preparation conditions and a clear processing window for manipulation of physiochemical properties of the nanoparticles (e.g., size and surface charge), which can be conditioned to exert control over protein encapsulation efficiency and subsequent release profile. The weakness of the chitosan nanoparticle system lies typically with difficulties in controlling initial burst effect in releasing large quantities of protein molecules. (C) 2007 Elsevier B.V. All rights reserved.

Emission lines of Fe X in active region spectra obtained with the Solar Extreme-ultraviolet Research Telescope and Spectrograph

Fully relativistic calculations of radiative rates and electron impact excitation cross-sections for Fe X are used to derive theoretical emission-line ratios involving transitions in the 174-366 angstrom wavelength range. A comparison of these with solar active region observations obtained during the 1989 and 1995 flights of the Solar Extreme-ultraviolet Research Telescope and Spectrograph (SERTS) reveals generally very good agreement between theory and experiment. Several Fe X emission features are detected for the first time in SERTS spectra, while the 3s(2)3p(5) P-2(3/2)-3s(2)3p(4)(S-1)3d D-2(3/2) transition at 195.32 angstrom is identified for the first time (to our knowledge) in an astronomical source. The most useful Fe X electron density (N-e) diagnostic line ratios are assessed to be 175.27/174.53 and 175.27/177.24, which both involve lines close in wavelength and free from blends, vary by factors of 13 between N-e = 10(8) and 10(11) cm(-3), and yet show little temperature sensitivity. Should these lines not be available, then the 257.25/345.74 ratio may be employed to determine N-e, although this requires an accurate evaluation of the instrument intensity calibration over a relatively large wavelength range. However, if the weak 324.73 angstrom line of Fe X is reliably detected, the use of 324.73/345.74 or 257.25/324.73 is recommended over 257.25/345.74. Electron densities deduced from 175.27/174.53 and 175.27/177.24 for the stars Procyon and alpha Cen, using observations from the Extreme-Ultraviolet Explorer (EUVE) satellite, are found to be consistent and in agreement with the values of N-e determined from other diagnostic ratios in the EUVE spectra. A comparison of several theoretical extreme-ultraviolet Fe X line ratios with experimental values for a theta-pinch, for which the plasma parameters have been independently determined, reveals reasonable agreement between theory and observation, providing some independent support for the accuracy of the adopted atomic data.

Microsatellite analysis for determination of the mutagenicity of extremely low-frequency electromagnetic fields and ionising radiation in vitro.

Extremely low-frequency electromagnetic fields (ELF-EMF) have been reported to induce lesions in DNA and to enhance the mutagenicity of ionising radiation. However, the significance of these findings is uncertain because the determination of the carcinogenic potential of EMFs has largely been based on investigations of large chromosomal aberrations. Using a more sensitive method of detecting DNA damage involving microsatellite sequences, we observed that exposure of UVW human glioma cells to ELF-EMF alone at a field strength of 1 mT (50 Hz) for 12 h gave rise to 0.011 mutations/locus/cell. This was equivalent to a 3.75-fold increase in mutation induction compared with unexposed controls. Furthermore, ELF-EMF increased the mutagenic capacity of 0.3 and 3 Gy gamma-irradiation by factors of 2.6 and 2.75, respectively. These results suggest not only that ELF-EMF is mutagenic as a single agent but also that it can potentiate the mutagenicity of ionising radiation. Treatment with 0.3 Gy induced more than 10 times more mutations per unit dose than irradiation with 3 Gy, indicating hypermutability at low dose.

A Geostatistical Investigation into Changing Permeability of Sandstones During Weathering Simulations

The ability to predict the behavior of masonry materials is crucial to conserve building stone. Natural stone, such as sandstone, is not immune from the processes of weathering in the built environment and suffers from decay by granular disintegration, contour scaling, and multiple flaking. Spatial variation of rock properties is a major contributing factor to inconsistent responses to weathering. This has implications for moisture movement and salt input and output and storage, and results in unpredictability in the decay dynamics of masonry materials. This article explores the use of variography and kriging to investigate the spatial interactions between the trigger factors of stone decay, in particular, permeability and its effect on salt penetration. Sandstone blocks were used to represent fresh building stones from a weathering perspective and gave baseline characteristics for the interpretation of subsequent deterioration and decay pathways. Simulated weathering trials involved preloading a sandstone block with salt and subjecting a separate block to 20 cycles of a weathering trial designed to simulate a temperate weathering regime. Geostatistical analysis indicated differences in the spatial variation of permeability of the fresh rock and that subjected to the weathering regimes. Spatial prediction and visualization showed differences in the spatial continuity of permeability in a horizontal and vertical direction through the preloaded block after salt weathering. Continual wetting with salt and alternate heating increased permeability in a vertical direction, enabling the ingress and movement of salt and moisture more effectively through the stone.

Tunable Enhancement of High Harmonic Emission from Laser Solid Interactions

Coherent wake emission is a unique source of extreme ultraviolet radiation and has been recently shown to provide the basis for intense attosecond light. Here we present a novel scheme, supported by particle-in-cell simulations, demonstrating that enhancement and spectral control of the coherent wake emission signal can be achieved by modifying the interaction plasma density ramp. Significant tunable enhancement of harmonic emission is verified experimentally, with factors of > 50 in relative signal increase achieved in a narrow band of harmonics at the cutoff frequency.

Biorefining of perennial ryegrass for the production of nano-fibrillated cellulose

This study has demonstrated biorefining steps for ryegrass and silage at a pilot scale to extrude fibre cake for the production of nanofibrillated cellulose (NFC), a potentially green biomaterial for replacing conventional fillers in the manufacture of polymer composites. Further treatments of processed ryegrass fibres with mechanical shearing, microfluidising, hydrochloric acid (HCl)/ sulphuric acid and a four stage {ethylenediaminetetra-acetic acid, sodium hydroxide, sodium hypochlorite and HCl} hydrolysis yielded 43.8, 36.1, 25.6 and 39.8 kg t21 DM of NFCs respectively. The NFCs were characterised using microscopy, X-ray diffraction, dynamic light scattering, spectroscopy and thermogravimetry. The NFC had diameters from 3.0–9.1 nm and length 308 nm– 4.6 mm. NFC-polyvinyl alcohol composites containing NFC (5 wt%) exhibited enhanced Young’s modulus and thermal stability by factors of 2.5 and 2 respectively compared with control. The mass, energy, water and chemical balances of the four process steps were assessed to evaluate technical feasibility and also to provide baseline production data for scaling up. The microfluidised product has been identified as the best NFC product, but production cost needs to be reduced.

Reliability Assessment of 3-D Space Frame Structures Applying Stochastic Finite Element Analysis

Throughout design development of satellite structure, stress engineer is usually challenged with randomness in applied loads and material properties. To overcome such problem, a risk-based design is applied which estimates satellite structure probability of failure under static and thermal loads. Determining probability of failure can help to update initially applied factors of safety that were used during structure preliminary design phase. These factors of safety are related to the satellite mission objective. Sensitivity-based analysis is to be implemented in the context of finite element analysis (probabilistic finite element method or stochastic finite element method (SFEM)) to determine the probability of failure for satellite structure or one of its components.

Comparison of teleconsultations and face-to-face consultations:preliminary results of a United Kingdom multicentre teledermatology study

The objective of this multicentre study was to undertake a systematic comparison of face-to-face consultations and teleconsultations performed using low-cost videoconferencing equipment. One hundred and twenty-six patients were enrolled by their general practitioners across three sites. Each patient underwent a teleconsultation with a distant dermatologist followed by a traditional face-to-face consultation with a dermatologist. The main outcome measures were diagnostic concordance rates, management plans and patient and doctor satisfaction. One hundred and fifty-five diagnoses were identified by the face-to-face consultations from the sample of 126 patients. Identical diagnoses were recorded from both types of consultation in 59% of cases. Teledermatology consultations missed a secondary diagnosis in 6% of cases and were unable to make a useful diagnosis in 11% of cases. Wrong diagnoses were made by the teledermatologist in 4% of cases. Dermatologists were able to make a definitive diagnosis by face-to-face consultations in significantly more cases than by teleconsultations (P = 0.001). Where both types of consultation resulted in a single diagnosis there was a high level of agreement (kappa = 0.96, lower 95% confidence limit 0.91-1.00). Overall follow-up rates from both types of consultation were almost identical. Fifty per cent of patients seen could have been managed using a single videoconferenced teleconsultation without any requirement for further specialist intervention. Patients reported high levels of satisfaction with the teleconsultations. General practitioners reported that 75% of the teleconsultations were of educational benefit. This study illustrates the potential of telemedicine to diagnose and manage dermatology cases referred from primary care. Once the problem of image quality has been addressed, further studies will be required to investigate the cost-effectiveness of a teledermatology service and the potential consequences for the provision of dermatological services in the U.K.

Social work education and political conflict: preparing students to address the needs of victims and survivors of the Troubles in Northern Ireland

This paper reports on the evaluation of a European PEACE III sponsored teaching and learning project that was designed to enable social work students to better understand the needs of victims and survivors of the conflict in Northern Ireland. The paper begins with an introduction to policy, practice and educational contexts before reviewing the literature on social work, conflict and trauma. It also summarises key, innovative pedagogical approaches used in the teaching, including the use of ground rules, teaching teams consisting of lecturer and service user dyads, learning exercises and case studies. The paper then explains the evaluation methodology. This involved two surveys which returned 144 student and 34 practice teacher questionnaires. The findings revealed that
students were generally committed to this form of teaching and engagement with victims and survivors of the conflict, although some students reported that their attitudes towards this subject had were not changed. Some students also discussed how the conflict had affected their lives and the lives of families and friends; it is argued that such biographical details are crucial in developing new pedagogical approaches in this area.
Practice teachers who supervised some of these students on placement reported general levels of satisfaction with preparedness to work with conflict related situations but were less convinced that organisations were so committed. The paper concludes with a discussion of the study limitations and a recommendation for more robust methods of teaching and evaluation in this area of social work education and practice.

Adaptive Dialogue Strategy Selection through Imprecise Probabilistic Query Answering

In a human-computer dialogue system, the dialogue strategy can range from very restrictive to highly flexible. Each specific dialogue style has its pros and cons and a dialogue system needs to select the most appropriate style for a given user. During the course of interaction, the dialogue style can change based on a user’s response and the system observation of the user. This allows a dialogue system to understand a user better and provide a more suitable way of communication. Since measures of the quality of the user’s interaction with the system can be incomplete and uncertain, frameworks for reasoning with uncertain and incomplete information can help the system make better decisions when it chooses a dialogue strategy. In this paper, we investigate how to select a dialogue strategy based on aggregating the factors detected during the interaction with the user. For this purpose, we use probabilistic logic programming (PLP) to model probabilistic knowledge about how these factors will affect the degree of freedom of a dialogue. When a dialogue system needs to know which strategy is more suitable, an appropriate query can be executed against the PLP and a probabilistic solution with a degree of satisfaction is returned. The degree of satisfaction reveals how much the system can trust the probability attached to the solution.

Experiences and needs of bereaved carers during palliative and end-of-life care for people with chronic obstructive pulmonary disease

This study explored the experiences of palliative care that bereaved carers had while providing care to a dying loved one with chronic obstructive pulmonary disease (COPD).

Method: Semi-structured interviews were undertaken with nine carers whohad lost a loved one in the preceding 6 to 24 months.These interviews explored levels of satisfaction with disease management, symptom management, and end-of-life care. With permission, interviews were tape recorded, transcribed, and subjected to content analysis.

Findings: Three themes emerged from the data: the impact of the caring experience, the lack of support services, and end-of-life and bereavement support. Carers experienced carer burden, lack of access to support services, a need for palliative care, and bereavement support.

Conclusion: The findings provide a first insight into the experiences of carers of patients with advanced COPD. Bereaved carers of patients who had suffered advanced COPD reported that they had received inadequate support and had a range of unmet palliative care needs. Special attention should be paid to educating and supporting carers during their caring and bereavement periods to ensure that their quality of life is maintained or enhanced

Economic globalization, inequality and body mass index:a cross-national analysis of 127 countries

This article investigates to what extent the worldwide increase in body mass index (BMI) has been affected by economic globalization and inequality. We used time-series and longitudinal cross-national analysis of 127 countries from 1980 to 2008. Data on mean adult BMI were obtained from the Global Burden of Metabolic Risk Factors of Chronic Diseases Collaborating Group. Globalization was measured using the Swiss Economic Institute (KOF) index of economic globalization. Economic inequality between countries was measured with the mean difference in gross domestic product per capita purchasing power parity in international dollars. Economic inequality within countries was measured using the Gini index from the Standardized World Income Inequality Database. Other covariates including poverty, population size, urban population, openness to trade and foreign direct investment were taken from the World Development Indicators (WDI) database. Time-series regression analyses showed that the global increase in BMI is positively associated with both the index of economic globalization and inequality between countries, after adjustment for covariates. Longitudinal panel data analyses showed that the association between economic globalization and BMI is robust after controlling for all covariates and using different estimators. The association between economic inequality within countries and BMI, however, was significant only among high-income nations. More research is needed to study the pathways between economic globalization and BMI. These findings, however, contribute to explaining how contemporary globalization can be reformed to promote better health and control the global obesity epidemic. © 2013 Copyright Taylor and Francis Group, LLC.

Primary assembly of soil communities: disentangling the effect of dispersal and local environment

It has long been recognised that dispersal abilities and environmental factors are important in shaping invertebrate communities, but their relative importance for primary soil community assembly has not yet been disentangled. By studying soil communities along chronosequences on four recently emerged nunataks (ice-free land in glacial areas) in Iceland, we replicated environmental conditions spatially at various geographical distances. This allowed us to determine the underlying factors of primary community assembly with the help of metacommunity theories that predict different levels of dispersal constraints and effects of the local environment. Comparing community assembly of the nunataks with that of non-isolated deglaciated areas indicated that isolation of a few kilometres did not affect the colonisation of the soil invertebrates. When accounting for effects of geographical distances, soil age and plant richness explained a significant part of the variance observed in the distribution of the oribatid mites and collembola communities, respectively. Furthermore, null model analyses revealed less co-occurrence than expected by chance and also convergence in the body size ratio of co-occurring oribatids, which is consistent with species sorting. Geographical distances influenced species composition, indicating that the community is also assembled by dispersal, e.g. mass effect. When all the results are linked together, they demonstrate that local environmental factors are important in structuring the soil community assembly, but are accompanied with effects of dispersal that may "override" the visible effect of the local environment.

An exploration of seniors’ motivation to use mobile brain-exercise software

This article reports on the development of an iPhone-based brain-exercise tool for seniors involving a series of focus groups (FGs) and field trials (FTs). Four FGs with 34 participants were conducted aimed at understanding the underlying motivational and de-motivational factors influencing seniors’ engagement with mobile brain-exercise software. As part of the FGs, participants had approximately 40 minutes hands-on experience with commercially available brain-exercise software. A content analysis was conducted on the data resulting in a ranking of 19 motivational factors, of which the top three were challenge, usefulness and familiarity and 15 de-motivational factors, of which the top-three were usability issues, poor communication and games that were too fast. Findings were used to inform the design of three prototype brain-exercise games for the iPhone contained within one overall application, named Brain jog. Subsequently, two FTs were conducted using Brain jog to investigate the part that time exposure has to play in shaping the factors influencing engagement. New factors arose with respect to the initial FGs including the motivational factor feedback and the de-motivational factor boring. The results of this research provide valuable guidelines for the design and evaluation of mobile brain-exercise software for seniors.