3,688 research outputs found

    Oxygen isotope geochemistry of the second HSDP core

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    Oxygen isotope ratios were measured in olivine phenocrysts (~1 mm diameter), olivine microphenocrysts (generally ~100–200 µm diameter), glass, and/or matrix from 89 samples collected from depths down to 3079.7 m in the second, and main, HSDP core (HSDP-2). Olivine phenocrysts from 11 samples from Mauna Loa and 34 samples from the submarine section of Mauna Kea volcano have delta18O values that are similar to one another (5.11 ± 0.10‰, 1sigma, for Mauna Loa; 5.01 ± 0.07‰, for submarine Mauna Kea) and within the range of values typical of olivines from oceanic basalts (delta18O of ~5.0 to 5.2‰). In contrast, delta18O values of olivine phenocrysts from 20 samples taken from the subaerial section of Mauna Kea volcano (278 to 1037 mbsl) average 4.79 ± 0.13‰. Microphenocrysts in both the subaerial (n = 2) and submarine (n = 24) sections of Mauna Kea are on average ~0.2‰ lower in delta18O than phenocrysts within the same stratigraphic interval; those in submarine Mauna Kea lavas have an average delta18O of 4.83 ± 0.11‰. Microphenocrysts in submarine Mauna Kea lavas and phencrysts in Mauna Loa lavas are the only population of olivines considered in this study that are typically in oxygen isotope exchange equilibrium with coexisting glass or groundmass. These data confirm the previous observation that the stratigraphic boundary between Mauna Loa and Mauna Kea lavas defines a shift from “normal” to unusually low delta18O values. Significantly, they also document that the distinctive 18O-depleted character of subaerial Mauna Kea lavas is absent in phenocrysts of submarine Mauna Kea lavas. Several lines of evidence suggest that little if any of the observed variations in delta18O can be attributed to subsolidus alteration or equilibrium fractionations accompanying partial melting or crystallization. Instead, they reflect variable proportions of an 18O-depleted source component or contaminant from the lithosphere and/or volcanic edifice that is absent in or only a trace constituent of subaerial Mauna Loa lavas, a minor component of submarine Mauna Kea lavas, and a major component of subaerial Mauna Kea lavas. Relationships between the delta18O of phenocrysts, microphenocrysts, and glass or groundmass indicate that this component (when present) was added over the course of crystallization-differentiation. This process must have taken place in the lithosphere and most likely at depths of between ~5 and 15 km. We conclude that the low-delta18O component is either a contaminant from the volcanic edifice that was sampled in increasingly greater proportions as the volcano drifted off the center of the Hawaiian plume or a partial melt of low-delta18O, hydrothermally altered perdotites in the shallow Pacific lithosphere that increasingly contributed to Mauna Kea lavas near end of the volcano's shield building stage. The first of these alternatives is favored by the difference in delta18O between subaerial and submarine Mauna Kea lavas, whereas the second is favored by systematic differences in radiogenic and trace element composition between higher and lower delta18O lavas

    A qualitative study of the views of residents with dementia, their relatives and staff about work practice in long-term care settings

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    Background: Most people living in 24-hour care settings have dementia, and little is known about what makes long-term care a positive experience for them.Method: This carer-led qualitative study examined working practices in 24-hour long-term care-settings, including hospitals, nursing and residential homes, with the aim of finding out and making recommendations about such settings. Using semi-structured interviews, managers, nurses and care assistants were asked about work practices, such as how they coped with difficult behavior, about shifts, staffing levels, staff retention and training. Relatives of residents with dementia were asked about their role and perceptions of the care provided, and residents were asked for their opinions of their care.Results: Staff reported that residents presented with increasingly challenging behavior compared to the past, and that sometimes staffing levels and skills were inadequate. Of all the settings, hospitals had the most problems with staffing levels and retention, staff-relative relationships and staff support systems. Relatives saw their own role as positive. People with dementia of varying severity could usefully evaluate some of the services they received.Discussion: Dementia-specific training and education of staff in all long-term care-settings, including induction, should address the management of problem behavior in dementia and thereby improve staff fulfilment and relatives' satisfaction. The long-stay hospital may not be appropriate as a "home for life" for those with dementia, and we recommend that long-stay care settings should be able to cater flexibly for a range of resident needs

    Factor VIII assay variability in postinfusion samples containing full length and B-domain deleted FVIII

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    Introduction Although the variability in factor VIII (FVIII):C measurement is well recognized, this has not been widely reported for post-FVIII infusion samples. Aim/Methods Three samples from haemophilia A patients were distributed in a UK National External Quality Assessment Scheme survey, each after treatment with either ReFacto AF, Kogenate FS or Advate. Fifty-two UK haemophilia centres performed FVIII assays using one-stage (n = 46) and chromogenic (n = 10) assays. Centres calibrated assays with the local plasma standard and with ReFacto AF laboratory standard for the ReFacto AF sample. Results/Conclusions Chromogenic assays gave significantly higher results than one-stage assays (P < 0.0001, 32% difference) in the post-Kogenate sample but not in the post-ReFacto AF (11% higher by chromogenic assay, ns) or post-Advate samples (3% lower by chromogenic, ns) when assays were calibrated with plasma standards. Twenty centres used all Instrumentation Laboratory (IL)-activated partial thromboplastin time reagents (Synthasil)/IL deficient plasma/reference plasma) in the one-stage assay and 15 used all Siemens reagents (Actin FS/Siemens deficient plasma/reference plasma); this made a significant difference to results post-ReFacto AF (41% higher by IL reagents, P < 0.0001) and Advate (39% higher by IL reagents, P < 0.0001), but not Kogenate (7% higher by IL, ns) when calibrated with plasma standards. Differences between results obtained with different one-stage assay reagents for monitoring Advate have implications for dosing patients. Furthermore, there was considerable inter-laboratory variation as indicated by CVs in the range 15–26% for chromogenic assay and 12–19% for one-stage assay results. This study suggests that external quality assessment schemes should offer participation in post-FVIII infusion schemes where haemophilic patients are monitored

    Micro-Analysis of D/H Ratios in Mantle Minerals by Carrier-Gas Mass Spectrometry

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    Isotopic analysis of water released by vacuum heating of hydrous minerals and sub-marine basaltic glasses indicates that they vary in δD_(SMOW) between ca. +10 and -115 per mil (e.g., [1]). However, with few exceptions variations within that range are not well correlated with other geochemical and geologic properties and it is debated whether they reflect isotopic heterogeneity in the mantle, fractionations produced during ascent to the surface, or sub-solidus alteration. This ambiguity is at least partly due to the large sample size and slow rate of conventional analyses, which precludes linking isotopic ranges to grain-scale petrographic variables or constructing large data bases (many 10’s of samples) in a reasonable period of time. Ion microprobe methods provide one solution to these problems, although they suffer from analytical uncertainties nominally 5 to 10 times worse than conventional measurements and large fractionations that can be a source of systematic error

    Trends in the availability and usage of electrophysical agents in physiotherapy practices from 1990 to 2010: A review

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    This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 Maney PublishingBackground: The use of electrophysical agents has a historically important role in physiotherapy practice. There are anecdotal reports that the availability and usage of electrotherapy modalities are declining, which may have implications for physiotherapy practice. The aim of this literature review was to provide scientific evidence on electrotherapy usage in the last 20 years by identifying trends in availability, use, and non-use of nine electrotherapeutic modalities in physiotherapy practices during 1990s and 2000s. Methods: Review of empirical studies published in the English language from 1990 to 2010 and identified through searching online bibliographic databases, which included: Medline/OvidSP, PubMed Central, CINAHL/EBSCOhost, ScienceDirect, Scopus, ISI Web of Science, and Google Scholar. Findings: In the last 20 years, ultrasound availability and usage show increasing trends in several countries. The availability and use of pulsed shortwave diathermy and laser have shown steady trends. Transcutaneous electrical nerve stimulation, interferential, and biofeedback availability and usage have shown increasing trends in the UK and decreasing trends in Australia and the Republic of Ireland. Trends of continuous shortwave diathermy availability and use are declining irrespective of the country of the study. The availability and usage of microwave diathermy and H-wave show steeply declining trends, while there is a sharp rise in their non-availability over the last several years. Conclusions: The availability and use of electrophysical agents have greatly changed in the last 20 years. Declining trends in the availability and usage along with increasing trend of non-availability of electrotherapy modalities may have implications for electrotherapy education, training, and practice in the coming years.This study was funded by Health & Safety Executive, UK (grant no. 4371/R47.022)

    Aberrations in shift-invariant linear optical imaging systems using partially coherent fields

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    Here the role and influence of aberrations in optical imaging systems employing partially coherent complex scalar fields is studied. Imaging systems require aberrations to yield contrast in the output image. For linear shift-invariant optical systems, we develop an expression for the output cross-spectral density under the space-frequency formulation of statistically stationary partially coherentfields. We also develop expressions for the output cross{spectral density and associated spectral density for weak-phase, weak-phase-amplitude, and single-material objects in one transverse spatial dimension

    Lens or prism? How organisations sustain multiple and competing reputations

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    Purpose: This paper challenges singular definitions, measurements and applications of corporate reputation which tend to be reductionist. We rebuff such narrow representations of reputation by showing the multiplicity of reputation in the case of a global management consulting firm and demonstrate how it has sustained such reputations. Design/methodology/approach: Using a large cross-country qualitative case study based on interviews, focus groups, non-participant observations, workshops and a fieldwork diary, dimensions of reputation are highlighted by drawing on perceptions from multiple stakeholder groups in different geographies. Findings: We find significant differences in perceptions of reputation between and within stakeholder groups, with perceptions changing across dimensions and geographies. Originality/value: The theoretical implications of the research indicate a plurality of extant reputations, suggesting that a prism is more suited to representing corporate reputation than a singular lens-like focus which is too narrow to constitute reputation. This paper offers theoretical and practical suggestions for how global firms can build and sustain multiple and competing corporate reputations

    The Prognostic Value of Brain Extracellular Fluid Nitric Oxide Metabolites After Traumatic Brain Injury.

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    BACKGROUND: Nitric oxide (NO) is a compound with both protective and damaging effects on neurons. Quantification of NO metabolites in humans is limited by sample contamination with blood. In vivo cerebral microdialysis may offer an alternative approach as sampling of extracellular fluid (ECF) adjacent to neurons becomes possible. We investigate the prognostic value of brain ECF NO metabolites in patients with traumatic brain injury (TBI). METHODS: A prospective case cohort of 195 ECF samples collected from 11 cases over 4 days following TBI was collected. Nitrate and nitrite concentrations ([NO( x )]) were quantified using a vanadium-based colorimetric assay. RESULTS: Early ECF [NO( x )] (<48 h post TBI) were significantly higher in non-survivors (median 59.2 μmol/l, n = 7) compared to survivors (23.3 μmol/l, n = 4) (P = 0.04). Late (48-96 h) ECF [NO( x )] remained higher in non-survivors (47.9 μmol/l) compared to survivors (23.0 μmol/l) but this was not significant (P = 0.29). Receiver operator characteristic analysis shows an optimized cutoff level for ECF [NO( x )] of 26.5 μmol/l measured <48 h post TBI for predicting non-survival (sensitivity 100%, specificity 75%). CONCLUSION: Early ECF NO( x ) concentrations are of prognostic value after TBI. ECF NO( x ) may be a useful biomarker for treatment trials targeted at nitric oxide metabolism

    A framework of place branding, place image, and place reputation: antecedents and moderators

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    Purpose – This paper develops a framework that links the concepts of place branding, place image, and place reputation. Focusing on the antecedents and outcomes of place branding in the context of an emerging country, namely Iran, the model further examines critical moderation variables. Design/methodology/approach – A qualitative approach was undertaken, comprising face-to-face in-depth interviews with fifteen respondents, involved in communicating about their country for various purposes such as encouraging tourism, promoting exports, and attracting investments. Based on analysis of the qualitative data, a comprehensive framework for place branding was formulated. Findings – Findings indicate that the key indicators of identifying a place brand come under two headings, namely national culture (country’s name, country’s brand, country attributes, social changes, geography and environment, people, culture (history, language, etc.), and infrastructure (security, economic condition, technological advancement, tourism development goals, place marketing and promotional strategy), which influences on the favorability of place branding. In addition, five main moderators of the outcomes of place branding were identified, namely, political perception, social media and news, place awareness, place association, and tourism experience. Practical implications – Effective place branding could help a country attract tourists, visitors, traders, and investors. Place branding should be considered a constructive tool that can be successfully applied to managing a country’s image. Originality/value – Place branding has received little attention in the context of emerging markets. This is the first known study undertaken with a view to understand and develop a place branding model that links with place image and place reputation in an emerging country. The study identifies twelve antecedents of place branding and five important moderators. Findings will help policy makers, country brand managers, and communication professionals more generally who deal with a country’s image and reputation and those involved in improving the tourism industry in Iran
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