Variations in tephra stratigraphy created by small-scale surface features in sub-polar landscapes

Financial support for this work was provided by NERC Doctoral Training Partnership Ph.D. studentship NE/L002558/1 to Polly I. J. Thompson.We explore the effect small-scale surface features have on influencing the morphology and grain-size distribution (GSD) of tephra layers within the Quaternary stratigraphy of sub-polar landscapes. Icelandic thúfur, small cryogenic earth mounds, are used to assess how and why the morphology and GSD of tephra layers vary over such formations. Through measurement of tephra layer thickness and GSD, Hekla 1947 and Grímsvötn 2011 tephra layers are analysed. Results indicate that such microtopographic features do indeed alter the form of tephra deposits and therefore the tephra layer that is preserved in the stratigraphy. Tephra thickness is significantly greater in hollows than on the thúfur crests. There is greater variation in tephra thickness measurements from thúfur in comparison to control measurements from a surface where thúfur are absent. Thúfur crests contain larger grain sizes than hollows, for both H1947 and G2011 tephras; however this was only statistically significant for the G2011 tephra. Such morphological patterns are thought to arise from an interplay of tephra characteristics, altered topography from the thúfur formations and earth surface processes operating at the sites. This study provides insight into the potential of tephra layer morphology and internal structures as indicators of Quaternary landforms and processes. Additionally, it provides important context for the appropriate sampling of tephra layers to infer volcanological processes, as the characteristics of preserved layers do not necessarily reflect those of the original fall-out.Publisher PDFPeer reviewe

Topography driven spreading

Roughening a hydrophobic surface enhances its nonwetting properties into superhydrophobicity. For liquids other than water, roughness can induce a complete rollup of a droplet. However, topographic effects can also enhance partial wetting by a given liquid into complete wetting to create superwetting. In this work, a model system of spreading droplets of a nonvolatile liquid on surfaces having lithographically produced pillars is used to show that superwetting also modifies the dynamics of spreading. The edge speed-dynamic contact angle relation is shown to obey a simple power law, and such power laws are shown to apply to naturally occurring surfaces

Frequency of blood glucose monitoring in relation to glycaemic control: observational study with diabetes database

Objectives: To investigate patterns of self monitoring of blood glucose concentration in diabetic patients who use insulin and to determine whether frequency of self monitoring is related to glycaemic control. Setting: Diabetes database, Tayside, Scotland. Subjects: Patients resident in Tayside in 1993­-5 who were using insulin and were registered on the database and diagnosed with insulin dependent (type 1) or non­insulin dependent (type 2) diabetes before 1993. Main outcome measures: Number of glucose monitoring reagent strips dispensed (reagent strip uptake) derived from records of prescriptions. First recorded haemoglobin A1c concentration in the study period, and reagent strips dispensed in the previous 6 months. Results: Among 807 patients with type 1 diabetes, 128 (16%) did not redeem any prescriptions for glucose monitoring reagent strips in the 3 year study period. Only 161 (20%) redeemed prescriptions for enough reagent strips to test glucose daily. The corresponding figures for the 790 patients with type 2 diabetes who used insulin were 162 (21%; no strips) and 131 (17%; daily tests). Reagent strip uptake was influenced both by age and by deprivation category. There was a direct relation between uptake and glycaemic control for 258 patients (with recorded haemoglobin A1c concentrations) with type 1 diabetes. In a linear regression model the decrease in haemoglobin A1c concentration for every extra 180 reagent strips dispensed was 0.7%. For the 290 patients with type 2 diabetes who used insulin there was no such relation. Conclusions: Self monitoring of blood glucose concentration is associated with improved glycaemic control in patients with type 1 diabetes. Regular self monitoring in patients with type 1 and type 2 diabetes is uncommon

Diagnosis of Scrub Typhus

Scrub typhus is transmitted by trombiculid mites and is endemic to East and Southeast Asia and Northern Australia. The clinical syndrome classically consists of a fever, rash, and eschar, but scrub typhus also commonly presents as an undifferentiated fever that requires laboratory confirmation of the diagnosis, usually by indirect fluorescent antibody (IFA) assay. We discuss the limitations of IFA, debate the value of other methods based on antigen detection and nucleic acid amplification, and outline recommendations for future study

Sustainable intensification of aquaculture value chains between Asia and Europe: A framework for understanding impacts and challenges

Sustainable intensification (SI) is defined and interpreted in terms of a framework to support production of farmed aquatic animals in Asia and their trade with Europe. A novel holistic perspective to value chain analysis, informed by a range of sustainability tools, is used to explain the dynamic in the trade that is having significant impacts on livelihoods in both regions. The origins of SI in agriculture are first described and their congruence with aquaculture clarified. Asian aquaculture systems, based on their emergent properties, are then located within a SI framework considering possible boundaries (enterprise, zone or whole value chain). The implications of conventional intensification, and alternatives are explored with reference to specific examples and impacts on the local and global environment, human and aquatic animal health and welfare. The challenges to sustainability of such value chains and implications for their governance, food culture and consumer habits are considered. Local consumption of seafood in Asia is found to be a major driver of growth and alternative markets for exports regionally and in Low and Medium income countries (LMIC) are likely to impact on employment and power in the value chain between Europe and Asia. The benefits of viewing farmed seafood as part of broader food landscapes are identified in the analysis, as is a shift in the focus from volume to value in terms of goal setting. More holistic perspectives of sustainability also emerge as necessary to describe and interpret global value chains rather than limited reductionist, production- orientated views. A diversity of trends in the development of farmed seafood is identified in contrast to any simplistic move to intensification, likely informed by economic, environmental and social factors in producer and consumer countries.  Statement of relevance  Global imbalances in production and consumption of farmed seafood are stimulating trade between Asia and Europe. The dynamic of global value chains around this emergent trade and their alignment with broader sustainability criteria, as applied to sustainable intensification of food production, are highly relevant to global food security

Noradrenergic α1 Receptor Antagonist Treatment Attenuates Positive Subjective Effects of Cocaine in Humans: A Randomized Trial

Preclinical research implicates dopaminergic and noradrenergic mechanisms in mediating the reinforcing effects of drugs of abuse, including cocaine. The objective of this study was to evaluate the impact of treatment with the noradrenergic α(1) receptor antagonist doxazosin on the positive subjective effects of cocaine.Thirteen non-treatment seeking, cocaine-dependent volunteers completed this single-site, randomized, placebo-controlled, within-subjects study. In one study phase volunteers received placebo and in the other they received doxazosin, with the order counterbalanced across participants. Study medication was masked by over-encapsulating doxazosin tablets and matched placebo lactose served as the control. Study medication treatment was initiated at 1 mg doxazosin or equivalent number of placebo capsules PO/day and increased every three days by 1 mg. After receiving 4 mg doxazosin or equivalent number of placebo capsules participants received masked doses of 20 and 40 mg cocaine IV in that order with placebo saline randomly interspersed to maintain the blind.Doxazosin treatment was well tolerated and doxazosin alone produced minimal changes in heart rate and blood pressure. During treatment with placebo, cocaine produced dose-dependent increases in subjective effect ratings of "high", "stimulated", "like cocaine", "desire cocaine", "any drug effect", and "likely to use cocaine if had access" (p<.001). Doxazosin treatment significantly attenuated the effects of 20 mg cocaine on ratings of "stimulated", "like cocaine", and "likely to use cocaine if had access" (p<.05). There were trends for doxazosin to reduce ratings of "stimulated", "desire cocaine", and "likely to use cocaine if had access" (p<.10).Medications that block noradrenergic α₁ receptors, such as doxazosin, may be useful as treatments for cocaine dependence, and should be evaluated further.Clinicaltrials.gov NCT01062945