Clustering and formation of nano-precipitates in dilute aluminium and magnesium alloys

Abstract A nuclear magnetic resonance (NMR) method is described for monitoring the evolution of nano-scale precipitate structures in dilute aluminium and magnesium-based alloys. Three examples are given of recent work in this field: (i) 63 Cu detection of Guinier -Preston zones (GPZs) and u-phases in Al(Cu), (ii) 27 Al detection of g-phase (Mg 17 Al 12 ) formation in Mg(Al) alloys and (iii) 45 Sc detection of Al 3 Sc formation in Al(Sc) alloys.

Failure of interpolation in the intuitionistic logic of constant domains

This paper shows that the interpolation theorem fails in the intuitionistic logic of constant domains. This result refutes two previously published claims that the interpolation property holds.Comment: 13 pages, 0 figures. Overlaps with arXiv 1202.1195 removed, the text thouroughly reworked in terms of notation and style, historical notes as well as some other minor details adde

Rapid detection of arsenic minerals using portable broadband NQR

The remote real-time detection of specific arsenic species would significantly benefit in minerals processing to mitigate the release of arsenic into aquatic environments and aid in selective mining. At present, there are no technologies available to detect arsenic minerals in bulk volumes outside of laboratories. Here we report on the first room-temperature broadband 75As nuclear quadrupole resonance (NQR) detection of common and abundant arsenic ores in the Earth crust using a large sample (0.78 L) volume prototype sensor. Broadband excitation aids in detection of natural minerals with low crystallinity. We briefly discuss how the proposed NQR detector could be employed in mining operations. Key Points Transformation of chemical analysis method to geophysical detection technologyFirst NQR ore characterization of selected arsenic minerals in bulk volumesBroadband NQR sensor to detect arsenic minerals with low crystallinit

Vacuolar iron stores gated by NRAMP3 and NRAMP4 are the primary source of iron in germinating seeds

During seed germination, iron (Fe) stored in vacuoles is exported by the redundant NRAMP3 and NRAMP4 transporter proteins. A double nramp3 nramp4 mutant is unable to mobilize Fe stores and does not develop in the absence of external Fe. We used RNA sequencing to compare gene expression in nramp3 nramp4 and wild type during germination and early seedling development. Even though sufficient Fe was supplied, the Fe-responsive transcription factors bHLH38, 39, 100, and 101 and their downstream targets FRO2 and IRT1 mediating Fe uptake were strongly upregulated in the nramp3 nramp4 mutant. Activation of the Fe deficiency response was confirmed by increased ferric chelate reductase activity in the mutant. At early stages, genes important for chloroplast redox control (FSD1 and SAPX), Fe homeostasis (FER1 and SUFB), and chlorophyll metabolism (HEMA1 and NYC1) were downregulated, indicating limited Fe availability in plastids. In contrast, expression of FRO3, encoding a ferric reductase involved in Fe import into the mitochondria, was maintained, and Fe-dependent enzymes in the mitochondria were unaffected in nramp3 nramp4. Together, these data show that a failure to mobilize Fe stores during germination triggered Fe deficiency responses and strongly affected plastids, but not mitochondria

The development of multiple phases of superposed rifting in the Turkana Depression, East Africa: evidence from receiver functions

The Turkana Depression in Eastern Africa separates the elevated plateaus of East Africa to the south and Ethiopia-Yemen to the north. It remains unclear whether the Depression lacks dynamic mantle support, or if the entire East Africa region is dynamically supported and the Depression compensated isostatically by thinned crust. Also poorly understood is how Miocene-Recent extension has developed across the Depression, connecting spatially separated magmatic rift zones in Ethiopia and Kenya. Receiver function analysis is used to constrain Moho depth and bulk-crustal V P /V S ratio below new seismograph networks in the Depression, and on the northern Tanzania craton. Crustal thickness is ∼40 km below northern Uganda and 30–35 km below southern Ethiopia, but 20–30 km below most of the Depression, where mass-balance calculations reveal low elevations can be explained adequately by crustal thinning alone. Despite the fact that magmatism has occurred for 45 Ma across the Depression, more than 15 Ma before East African Rift (EAR) extension initiated, bulk crustal V P /V S across southern Ethiopia and the Turkana Depression (∼1.74) is similar to that observed in areas unaffected by Cenozoic rifting and magmatism. Evidence for voluminous lower crustal intrusions and/or melt, widespread below the Ethiopian rift and Ethiopian plateau to the north, is therefore lacking. These observations, when reviewed in light of high stretching factors (β ≤ 2.11), suggest Cenozoic extension has been dominated until recently by faulting and plate stretching, rather than magma intrusion, which is likely an incipient process, operating directly below seismically-active Lake Turkana. Early-stage EAR basins to the west of Lake Turkana, with associated stretching factors of β ≈ 2, formed in crust only moderately thinned during earlier rifting episodes. Conversely, ∼23 km-thick crust beneath the Kino Sogo Fault Belt (KSFB) has small offset faults and thin sedimentary strata, suggesting almost all of the observed stretching occurred in Mesozoic times. Despite the KSFB marking the shortest path between focused extensional zones to the north and south, seismicity and GPS data show that modern extension is localized below Lake Turkana to the west. Failed Mesozoic rift zones, now characterized by thinned crust and relatively refractory mantle lithosphere, are being circumnavigated, not exploited by EAR rifting

Continued Slow Decay of the Residual Plasma Viremia Level in HIV-1 – Infected Adults Receiving Long-term Antiretroviral Therapy

We measured plasma human immunodeficiency virus type 1 (HIV-1) RNA levels by means of single-copy assay in 334 participants receiving virologically suppressive antiretroviral therapy (ART). A residual viremia load of ≥1 copy/mL after 4 years of ART was predicted by a higher pre-ART HIV-1 RNA level, higher CD8+ T-cell count during treatment, and a lower ratio of CD4+ T cells to CD8+ T cells during treatment but not by initial ART regimen. In a longitudinal subset of 64 individuals, continued decay of the plasma HIV-1 RNA level was observed, with an average annual decrease of 6% and an estimated half-life of 11.5 years. In contrast to prior reports, the persistent viremia level continues to slowly decline during years 4–12 of suppressive ART

Effects of student-led drama on nursing students' attitudes to interprofessional working and nursing advocacy: A pre-test post-test educational intervention study

This is the final version. Available from Elsevier via the DOI in this record. Background: Nursing educators need to equip students to work in interprofessional teams and advocate for patients in increasingly integrated health and social care settings. Drama-based education has been used in nursing to help students understand complex concepts and practices, including communication, empathy, and patient safety. However, few studies have evaluated drama-based education to promote understanding of interprofessional care and advocacy, and none have involved student-led drama where students create dramatic performances to support learning. Objectives: To examine the effects of student-led drama on student nurses’ attitudes to interprofessional working and advocacy. Design: Pre-test post-test educational intervention study. Settings: Public university in Scotland. Participants: 400 undergraduate student nurses enrolled on a 15-week module focussed on health and social care integration and interprofessional working. Methods: Students completed paper questionnaires at the start (n = 274, response rate: 80.1 %) and end (n = 175, 63.9 %) of the module. Outcome measures were the validated Attitudes Towards Healthcare Teams Scale (ATHCTS) and Protective Nursing Advocacy Scale (PNAS). Change in mean ATHCTS and PNAS scores were assessed using paired samples t-tests, with Cohen’s d to estimate effect size. Results: ATHCTS scores significantly increased from 3.87 to 4.19 (p < 0.001, d = 0.52). PNAS scores increased from 3.58 to 3.81 (p < 0.001, d = 0.79), with significant improvements in the ‘acting as an advocate’ (4.18 to 4.51, p < 0.001, d = 0.81) and ‘environmental and educational influences’ subscales (3.79 to 4.13, p < 0.001, d = 0.75). Statements focussed on promoting holistic, dignified care and enabling health professionals to be responsive to emotional and financial needs of patients, showed greatest change. Conclusions: Education based on plays created and performed by student nurses led to significant improvements in student nurses’ attitudes towards interprofessional working and nursing advocacy. Student-led drama should be embedded in nursing curricula to enable students to understand the realities and complexities of health and social care integration and interprofessional workingEconomic and Social Research CouncilEdinburgh Napier Universit

The role of predicted chemotactic and hydrocarbon degrading taxa in natural source zone depletion at a legacy petroleum hydrocarbon site

Petroleum hydrocarbon contamination is a global problem which can cause long-term environmental damage and impacts water security. Natural source zone depletion (NSZD) is the natural degradation of such contaminants. Chemotaxis is an aspect of NSZD which is not fully understood, but one that grants microorganisms the ability to alter their motion in response to a chemical concentration gradient potentially enhancing petroleum NSZD mass removal rates. This study investigates the distribution of potentially chemotactic and hydrocarbon degrading microbes (CD) across the water table of a legacy petroleum hydrocarbon site near Perth, Western Australia in areas impacted by crude oil, diesel and jet fuel. Core samples were recovered and analysed for hydrocarbon contamination using gas chromatography. Predictive metagenomic profiling was undertaken to infer functionality using a combination of 16 S rRNA sequencing and PICRUSt2 analysis. Naphthalene contamination was found to significantly increase the occurrence of potential CD microbes, including members of the Comamonadaceae and Geobacteraceae families, which may enhance NSZD. Further work to explore and define this link is important for reliable estimation of biodegradation of petroleum hydrocarbon fuels. Furthermore, the outcomes suggest that the chemotactic parameter within existing NSZD models should be reviewed to accommodate CD accumulation in areas of naphthalene contamination, thereby providing a more accurate quantification of risk from petroleum impacts in subsurface environments, and the scale of risk mitigation due to NSZD