Positron annihilation lifetime spectroscopy as a probe of free volume in plasticized solid polymer electrolytes

A recent report on the correlation between enhanced polymer mobility and ionic conductivity at room temperature in plasticized polyether-urethane solid polymer electrolytes (Forsyth et al.[1]), has prompted the present investigation. Positron annihilation lifetime spectroscopy (PALS) has been used to study the effect of plasticizer addition on the room temperature free volume characteristics of the crosslinked polyether-urethane. The addition of low molecular weight plasticizers to the polyether-urethane results in a constant or decreasing mean free volume cavity radius, as measured by the orthoPositronium lifetime τ₃, and a decreasing relative concentration of free volume cavities as measured by the ortho-Positronium intensity, I₃. It is postulated that the plasticizers interrupt polymer-polymer interactions by occupying the inter- and intra-chain free volume. The plasticizer structure influences the polymerplasticizer interactions which affect inter- and intra-chain separation and hence the free volume of the system. The decrease in polymer-polymer interaction and the increase in polymer-plasticizer interaction in turn influence the glass transition temperature behaviour.

Localized relaxational dynamics of succinonitrile

Succinonitrile (N≡C—CH₂—CH₂—C≡N) is a good ionic conductor, when doped with an ionic compound, at room temperature, where it is in its plastic crystalline phase (Long et al. Solid State Ionics 2003, 161, 105; Alarco et al. Nat. Mater. 2004, 3, 476). We report on the relaxational dynamics of the plastic phase near the two first-order phase transitions and on the effect of dissolving a salt in the plastic matrix by quasi-elastic neutron scattering. At 240 K, the three observed relaxations are localized and we can describe their dynamics (τ ≈ 1.7, 17, and 140 ps) to a certain extent from a model using a single molecule that was proposed by B_ée et al. allowing for all conformations in its unit cell (space group IM3M). The extent of the localized motion as observed is however larger than that predicted by the model and suggests that the isomerization of succinonitrile is correlated with a jump to the nearest neighbor site in the unit cell. The salt containing system is known to be a good ionic conductor, and our results show that the effect of the ions on the succinonitrile matrix is homogeneous. Because the isomerizations and rotations are governed by intermolecular interactions, the dissolved ions have an effect over an extended range. Due to the addition of the salt, the dynamics of one of the components (τ ≈ 17 ps) shows more diffusive character at 300 K. The calculated upper limit of the corresponding diffusion constant of succinonitrile in the electrolyte is a factor 30 higher than what is reported for the ions. Our results suggest that the succinonitrile diffusion is caused by nearest neighbor jumps that are localized on the observed length and time scales.

Multidisciplinary team developed and implemented protocols to assist mechanical ventilation weaning : a systematic review of literature

Aim: The aim of this review was to determine if ventilation-weaning protocols developed and implemented by multidisciplinary teams (MDTs) reduced the duration of mechanical ventilation in adult intensive care patients compared to usual care.

Method: A systematic review was conducted to review published research studies from January 1999 to June 2009 to identify and analyse the best available evidence on MDT-based weaning protocols in adult intensive care patients. All relevant studies based on electronic searches of MEDLINE, EMBASE, CINAHL, the Cochrane Controlled Trials Registry and the Cochrane Database of Systematic Reviews were included. Where possible data were pooled and a meta-analysis performed. A narrative synthesis of data was conducted to provide a critical appraisal of nonrandomised controlled trials included in the review.

Results: Three pre- and postinterventional studies were identified for inclusion in this review. Results show equivocal support for weaning protocols developed and implemented by MDTs for reducing duration of mechanical ventilation.

Conclusion: Communication and organizational processes must be addressed for multidisciplinary protocols to be effective. Due to methodological limitations of included studies, large randomised controlled trials are required to provide high-level evidence of the effects of MDT-based protocols on duration of mechanical ventilation.

Solubilization of selected free fatty acids in palm oil by biodegradable ethoxylated surfactants

The solubilization of three major components, viz., palmitic, oleic, and linoleic acids, in palm oil by ethoxylated surfactants was investigated. The results were analyzed in terms of the molecular properties of surfactants and free fatty acids (FFAs). It was found that the solubilities of these FFAs in various micellar solutions depend not only on their octanol−water partition coefficients (Kow), but also on their physicochemical properties. The study on the solubilization kinetics was conducted by choosing palmitic acid as a model solubilizate and Tergitol 15-S-7 as the model surfactant. A first-order film diffusion model, which accounts for the direct uptake of organic molecules at a solid surface into surfactant micelles, was adopted to analyze the effect of surfactant on dissolution of palmitic acid. It was observed that the presence of surfactant reduced the mass-transfer coefficient. Instead, the overall mass-transfer rate was enhanced because of the much higher driving force from the increased solubilization capacity.

Multifactorial influences on and deviations from medication administration safety and quality in the acute medical/surgical context

Background and Aims: Although numerous factors influence medication administration, our understanding of the interplay of these factors on medication quality and safety is limited. The aim of this study was to explore the multifactorial influences on medication quality and safety in the context of a single checking policy for medication administration in acute care.

Approach: An exploratory/descriptive study using non-participant observation and follow-up interview was used to identify factors influencing medication quality and safety in medication administration episodes (n = 30). Observations focused on nurses’ interactions with patients during medication administration, and the characteristics of the environment in which these took place. Confirmation of observed data occurred on completion of the observation period during short semi-structured interviews with participant nurses.

Findings: Findings showed nurses developed therapeutic relationships with patients in terms of assessing patients before administering medications and educating patients about drugs during medication administration. Nurses experienced more frequent distractions when medications were stored and prepared in a communal drug room according to ward design. Nurses deviated from best-practice guidelines during medication administration.

Implications: Nurses’ abilities and readiness to develop therapeutic relationships with patients increased medication quality and safety, thereby protecting patients from potential adverse events. Deviations from best-practice medication administration had the potential to decrease medication safety. System factors such as ward design determining medication storage areas can be readily addressed to minimise potential error.

Conclusions: Nurses displayed behaviours that increased medication administration quality and safety; however, violations of practice standards were observed. These findings will inform future intervention studies to improve medication quality and safety.

Variations, trends and patterns of fish landings in large tropical reservoirs

Temporal variations of fish yields in four major reservoirs in Thailand (Ubolratana; Sirindhorn; Srinakarin; Vajiralongkorn) were investigated with the use of long-term fish landing data (≥20years). The long-term variations in fish yield, measured as the coefficient of variation of yearly yield, ranged mostly between 50% and 100%. For short-term variations, the means of the relative variation (85%) were larger than the absolute variation (63%). This finding indicates that short-term variations were inversely related to fish yield and that a higher uncertainty occurs when fish catches are low. The stocked exotic species exhibited higher variations than the indigenous species. The trend analyses indicated some species had sharply declined fish landings, while some species were quite stable (i.e. reservoir-adapted species). Stocked species tended to increase in relatively shallow reservoirs, compared to the deep reservoir. Fish landing data for each reservoir were patternized, using the self-organizing map, indicating temporal trends of chronological order. The differences among clusters in each reservoir were with respect to the weight of each species in the fish landings in each year, and temporal changes in species composition in the reservoirs, which would primarily be attributed to the environmental changes followed by anthropogenic pressures. The mean trophic level (τ) fluctuated, resulting from changes in species composition and weight of fish landing, as well as fish stocking programmes.

Can a targeted psychological intervention be effective for young people following a first manic episode? Results from an 18-month pilot study

Aim: There is a scarce literature describing psychological interventions for a young, first-episode cohort who have experienced psychotic mania. This study aimed to assess whether a manualized psychological intervention could be effective in reducing symptomatology and relapse, and improve functional outcome in this population.

Methods: The study was an open-label design, drawn from a larger pharmacotherapy trial. All participants in the pharmacotherapy trial were offered a manualized psychological intervention in addition to case management. Inclusion in the psychotherapy group was based on participant's choice, and on completion of four or more of the eight modules offered. All clinical files were audited to ensure accuracy of group allocation. Forty young people aged 15 to 25 years old who had experienced a manic episode with psychotic features were recruited into the study, with 20 people in the combined treatment as usual plus psychotherapy group (P+TAU), and an equal number of matched control participants who received treatment as usual (TAU) within the same service. All participants were prescribed antipsychotic and mood-stabilizing medication. Symptomatic, functional and relapse measures were taken both at baseline and at 18-month follow-up.

Results: Manic symptoms improved significantly for both groups, with no differences between groups. Depression scores and overall symptom severity were significantly lower in the P + TAU group. No differences were evident between groups with regard to numbers or type of relapse. The P + TAU group had significantly better social and occupational functioning after 18 months.

Conclusion: This study suggests that a manualized psychological intervention targeted to a first-episode population can be effective in reducing depression and overall symptom severity, and can improve functional outcome following a first episode of psychotic mania.

Composite indices: rank robustness, statistical association, and redundancy

This article evaluates the robustness of rankings obtained from composite indices that combine information from two or more components via a weighted sum. It examines the empirical prevalence of robust comparisons using the method proposed by Foster et al. (2010). Indices examined are the Human Development Index (HDI), the Index of Economic Freedom (IEF), and the Environmental Performance Index (EPI). Key theoretical results demonstrate links between the prevalence of robust comparisons, Kendall’s tau rank correlation coefficient, and statistical association across components. Implications for redundancy among index components are also examined.

Γεννημένος Δύο Φορές: η Dionysos Films και η Δημιουργία ενός Ελληνικού Κινηματογραφικού Κυκλώματος στην Αυστραλία

Από τα τέλη της δεκαετίας του ’40 μέχρι τα τέλη της δεκαετίας του ’70, το κέντρο και τα περίχωρα της Μελβούρνης στέγασαν ένα δυναμικό ελληνικό κινηματογραφικό κύκλωμα τριάντα περίπου διαφορετικών αιθουσών, οι οποίες λειτούργησαν υπό την εποπτεία ενός μικρού αριθμού καθετοποιημένων επιχειρήσεων προβολής/διανομής. Η Dionysos Films ήταν ανάμεσα στις πρώτες ελληνικές εταιρείες προβολής/διανομής που ιδρύθηκαν στην Αυστραλία και που από το 1949 ως το 1956 έδρασε χωρίς σημαντικό ανταγωνισμό, διαμορφώνοντας το πλαίσιο για ένα ελληνικό κινηματογραφικό κύκλωμα της διασποράς που εκτεινόταν από την επαρχιακή και μητροπολιτική Αυστραλία ως τη Νέα Ζηλανδία. Το παρόν άρθρο αναμετρά τη σκιά που έριξε η Dionysos Films (και ο χαρισματικός της ιδιοκτήτης Stathis Raftopoulos) στην ιστορία των κινηματογραφικών εμπειριών των Ελλήνων των Αντιπόδων καθώς και τις επιπτώσεις που έχει αυτή η ανεξερεύνητη πτυχή της αυστραλιανής, αλλά και της ελληνικής κινηματογραφικής ιστορίας, στον τρόπο που αντιλαμβανόμαστε τις εθνικές κινηματογραφίες των δύο χωρών.

Illness in old age is part of an individual's fate and must be approached with acceptance

Older members of the Greek community see aging and the ill health that may accompany it as an inevitable part of life. They associate illness very closely with God’s will, and largely believe their state of health is an aspect of fate and / or luck that they do not have control over and must simply accept. This paper, based on research conducted in Melbourne, Australia, describes the way in which the experience of old age is understood in the worldview of this group. The words fate and luck (τύχη = tyche; γραφτό = graphto) are often used by older Greeks to characterize their situation. Luck, to this group, is not random. The term (τύχη) was used in classical times to refer to a kind of minor deity that controlled the fortune of the Greek city states, and an element of this idea of intention remains today. In the modern context, luck comes from God, and for this group, is part of γραφτό, or destiny, something that is written. In its usual usage in Greek, γραφτό refers to something that must happen to a person because it is predetermined and cannot not occur. The meaning that these older Greek individuals give to the word luck in the modern world is manifested in their acceptance of the problems of aging and their approach to coping with their own experience.

Do parents, teachers and children use the SDQ in a similar fashion?

Few studies have investigated whether parents’, teachers’ and children’s responses to the strengths and difficulties questionnaire (SDQ) have equivalence. In this study, data from 854 matched questionnaires collected in Malaysia were subjected to tau equivalence confirmatory factor analysis, to assess if all three groups responded to the same target (the child) similarly. We first fitted Goodman’s (Journal of Child Psychology and Psychiatry, 38, 581–586, (1997a); Journal of Child Psychology and Psychiatry, 40, 791–801, 1997b) five factor model, but found that this did not fit the model despite attempts to improve and rectify model fit. We thereafter attempted to fit Dickey and Blumberg (Journal of the American Academy of Child Adolescent Psychiatry, 43, 1159–1167, 2004) three factor model, but similarly found a lack of fit. We then undertook an exploratory model with a random half of the data, obtaining a three factor solution, and tested this in a confirmatory tau equivalence model. The Unconstrained Model provided a fit to the data, revealing a similar structure across the three informant groups. As this fit was for the Unconstrained Model, it reveals that groups differ in the value they place on each of the variables but overall that held a similar underlying factor structure. The findings are discussed in relation to the possible cultural issues involved and the use of the SDQ.