Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland

This is the final version of the article. Available from EGU via the DOI in this record.Meltwater delivered to the bed of the Greenland Ice Sheet is a driver of variable ice-motion through changes in effective pressure and enhanced basal lubrication. Ice surface velocities have been shown to respond rapidly both to meltwater production at the surface and to drainage of supraglacial lakes, suggesting efficient transfer of meltwater from the supraglacial to subglacial hydrological systems. Although considerable effort is currently being directed towards improved modelling of the controlling surface and basal processes, modelling the temporal and spatial evolution of the transfer of melt to the bed has received less attention. Here we present the results of spatially distributed modelling for prediction of moulins and lake drainages on the Leverett Glacier in Southwest Greenland. The model is run for the 2009 and 2010 ablation seasons, and for future increased melt scenarios. The temporal pattern of modelled lake drainages are qualitatively comparable with those documented from analyses of repeat satellite imagery. The modelled timings and locations of delivery of meltwater to the bed also match well with observed temporal and spatial patterns of ice surface speed-ups. This is particularly true for the lower catchment ( < 1000 m a.s.l.) where both the model and observations indicate that the development of moulins is the main mechanism for the transfer of surface meltwater to the bed. At higher elevations (e.g. 1250-1500 m a.s.l.) the development and drainage of supraglacial lakes becomes increasingly important. At these higher elevations, the delay between modelled melt generation and subsequent delivery of melt to the bed matches the observ ed delay between the peak air temperatures and subsequent velocity speed-ups, while the instantaneous transfer of melt to the bed in a control simulation does not. Although both moulins and lake drainages are predicted to increase in number for future warmer climate scenarios, the lake drainages play an increasingly important role in both expanding the area over which melt accesses the bed and in enabling a greater proportion of surface melt to reach the bed.We acknowledge the College of Physical Sciences, University of Aberdeen, the Leverhulme Trust through a Study Abroad Studentship and the Swedish Radiation Safety Authority, for funding awarded to C. Clason. Data collection was supported by the UK Natural Environment Research Council (through a studentship to I. Bartholomew and grants to P. Nienow and D. Mair) and the Edinburgh University Moss Centenary Scholarship (I. Bartholomew)

Use of cyclic ion mobility spectrometry (cIM)-mass spectrometry to study the intramolecular transacylation of diclofenac acyl glucuronide

1-β-O-Acyl-glucuronides (AGs) are common metabolites of carboxylic acid-containing xenobiotics, including, e.g., many nonsteroidal anti-inflammatory drugs (NSAIDs). They are of concern to regulatory authorities because of the association of these metabolites with the hepatotoxicity that has resulted in drug withdrawal. One factor in assessing the potential risk posed by AGs is the rate of transacylation of the biosynthetic 1-β-O-acyl form to the 2-, 3-, and 4-O-acyl isomers. While transacylation can be measured using 1H NMR spectroscopy or liquid chromatography-mass spectrometry (LC-MS), the process can be time consuming and involve significant method development. The separation of these positional isomers by ion mobility spectrometry (IMS) has the potential to allow their rapid analysis, but conventional instruments lacked the resolving power to do this. Prediction of the collision cross section (CCS) using a machine learning model suggested that greater IMS resolution might be of use in this area. Cyclic IMS was evaluated for separating mixtures of isomeric AGs of diclofenac and was compared with a conventional ultraperformance liquid chromatography (UPLC)-MS method as a means for studying transacylation kinetics. The resolution of isomeric AGs was not seen using a conventional traveling wave IMS device; however, separation was seen after several passes around a cyclic IMS. The cyclic IMS enabled the degradation of the 1-β-O-acyl-isomer to be analyzed much more rapidly than by LC-MS. The ability of cyclic IMS to monitor the rate of AG transacylation at different pH values, without the need for a prior chromatographic separation, should allow high-throughput, real-time, monitoring of these types of reactions

Men with intellectual disabilities with a history of sexual offending: empathy for victims of sexual and non-sexual crimes

Background: The objectives were (a) to compare the general empathy abilities of men with intellectual disabilities (IDs) who had a history of sexual offending to men with IDs who had no known history of illegal behaviour, and (b) to determine whether men with IDs who had a history of sexual offending had different levels of specific victim empathy towards their own victim, in comparison to an unknown victim of sexual crime, and a victim of non-sexual crime, and make comparison to non-offenders. Methods: Men with mild IDs (N = 35) were asked to complete a measure of general empathy and a measure of specific victim empathy. All participants completed the victim empathy measure in relation to a hypothetical victim of a sexual offence, and a non-sexual crime, while additionally, men with a history of sexual offending were asked to complete this measure in relation to their own most recent victim. Results: Men with a history of sexual offending had significantly lower general empathy, and specific victim empathy towards an unknown sexual offence victim, than men with no known history of illegal behaviour. Men with a history of sexual offending had significantly lower victim empathy for their own victim than for an unknown sexual offence victim. Victim empathy towards an unknown victim of a non-sexual crime did not differ significantly between the two groups. Conclusions: The findings suggest that it is important include interventions within treatment programmes that attempt to improve empathy and perspective-taking

Growth and dislocation studies of β-HMX

Background: The defect structure of organic materials is important as it plays a major role in their crystal growth properties. It also can play a subcritical role in “hot-spot” detonation processes of energetics and one such energetic is cyclotetramethylene-tetranitramine, in the commonly used beta form (β-HMX). Results: The as-grown crystals grown by evaporation from acetone show prismatic, tabular and columnar habits, all with {011}, {110}, (010) and (101) faces. Etching on (010) surfaces revealed three different types of etch pits, two of which could be identified with either pure screw or pure edge dislocations, the third is shown to be an artifact of the twinning process that this material undergoes. Examination of the {011} and {110} surfaces show only one type of etch pit on each surface; however their natural asymmetry precludes the easy identification of their Burgers vector or dislocation type. Etching of cleaved {011} surfaces demonstrates that the etch pits can be associated with line dislocations. All dislocations appear randomly on the crystal surfaces and do not form alignments characteristic of mechanical deformation by dislocation slip. Conclusions: Crystals of β-HMX grown from acetone show good morphological agreement with that predicted by modelling, with three distinct crystal habits observed depending upon the supersaturation of the growth solution. Prismatic habit was favoured at low supersaturation, while tabular and columnar crystals were predominant at higher super saturations. The twin plane in β-HMX was identified as a (101) reflection plane. The low plasticity of β-HMX is shown by the lack of etch pit alignments corresponding to mechanically induced dislocation arrays. On untwinned {010} faces, two types of dislocations exist, pure edge dislocations with b = [010] and pure screw dislocations with b = [010]. On twinned (010) faces, a third dislocation type exists and it is proposed that these pits are associated with pure screw dislocations with b = [010]

An evaluation of the EQUIP treatment programme with men who have intellectual and developmental disabilities

Background: The Equipping Youth to Help One Another Programme (EQUIP) was designed for young offenders to address a developmental delay in moral reasoning, distorted cognitions and social skills. Methods: The present authors undertook a single case series study and piloted an adapted version of the EQUIP programme with three men with intellectual disabilities and four men with a diagnosis of Asperger Syndrome, all of whom were detained in a medium‐secure forensic unit for people with intellectual disabilities. Treatment was delivered over a 12‐week period, and participants took part in four‐one‐hour sessions per week. Results: The results suggested that treatment was successful at increasing moral reasoning ability, reducing distorted cognitions and improving ability to choose effective solutions to problems. However, treatment did not have a significant effect upon anger. Conclusions: The EQUIP programme is a promising treatment, but further research is needed to investigate its effectiveness with men with intellectual or other developmental disabilities

Elucidating the aetiology of human Campylobacter coli infections

Peer reviewedPublisher PD

How accurate is the phenotype? – An analysis of developmental noise in a cotton aphid clone

<p>Abstract</p> <p>Background</p> <p>The accuracy by which phenotype can be reproduced by genotype potentially is important in determining the stability, environmental sensitivity, and evolvability of morphology and other phenotypic traits. Because two sides of an individual represent independent development of the phenotype under identical genetic and environmental conditions, average body asymmetry (or "fluctuating asymmetry") can estimate the developmental instability of the population. The component of developmental instability not explained by intrapopulational differences in gene or environment (or their interaction) can be further defined as internal developmental noise. Surprisingly, developmental noise remains largely unexplored despite its potential influence on our interpretations of developmental stability, canalization, and evolvability. Proponents of fluctuating asymmetry as a bioindicator of environmental or genetic stress, often make the assumption that developmental noise is minimal and, therefore, that phenotype can respond sensitively to the environment. However, biologists still have not measured whether developmental noise actually comprises a significant fraction of the overall environmental response of fluctuating asymmetry observed within a population.</p> <p>Results</p> <p>In a morphometric study designed to partition developmental noise from fluctuating asymmetry in the wing morphology of a monoclonal culture of cotton aphid, <it>Aphis gossipyii</it>, it was discovered that fluctuating asymmetry in the aphid wing was nearly four times higher than in other insect species. Also, developmental noise comprised a surprisingly large fraction (≈ 50%) of the overall response of fluctuating asymmetry to a controlled graded temperature environment. Fluctuating asymmetry also correlated negatively with temperature, indicating that environmentally-stimulated changes in developmental instability are mediated mostly by changes in the development time of individuals.</p> <p>Conclusion</p> <p>The amount of developmental noise revealed in this trait potentially does interfere with a substantial amount of the sensitivity of fluctuating asymmetry to change in temperature. Assuming that some genetic-based variation in individual buffering of developmental instability exists in natural aphid populations, the amount of internal developmental noise determined in this study could also substantially reduce evolvability of the aphid wing. The overall findings here suggest that individual response to the seemingly high cost of stabilizing some aspects of the phenotype may account for the frequent observation of trait and species specificity in levels of fluctuating asymmetry.</p

Subglacial lake drainage detected beneath the Greenland ice sheet

The contribution of the Greenland ice sheet to sea-level rise has accelerated in recent decades. Subglacial lake drainage events can induce an ice sheet dynamic response—a process that has been observed in Antarctica, but not yet in Greenland, where the presence of subglacial lakes has only recently been discovered. Here we investigate the water flow paths from a subglacial lake, which drained beneath the Greenland ice sheet in 2011. Our observations suggest that the lake was fed by surface meltwater flowing down a nearby moulin, and that the draining water reached the ice margin via a subglacial tunnel. Interferometric synthetic aperture radar-derived measurements of ice surface motion acquired in 1995 suggest that a similar event may have occurred 16 years earlier, and we propose that, as the climate warms, increasing volumes of surface meltwater routed to the bed will cause such events to become more common in the future

Using sequence data to identify alternative routes and risk of infection: a case-study of campylobacter in Scotland

&lt;b&gt;Background:&lt;/b&gt; Genetic typing data are a potentially powerful resource for determining how infection is acquired. In this paper MLST typing was used to distinguish the routes and risks of infection of humans with Campylobacter jejuni from poultry and ruminant sources.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods:&lt;/b&gt; C. jejuni samples from animal and environmental sources and from reported human cases confirmed between June 2005 and September 2006 were typed using MLST. The STRUCTURE software was used to assign the specific sequence types of the sporadic human cases to a particular source. We then used mixed case-case logistic regression analysis to compare the risk factors for being infected with C. jejuni from different sources.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Results:&lt;/b&gt; A total of 1,599 (46.3%) cases were assigned to poultry, 1,070 (31.0%) to ruminant and 67 (1.9%) to wild bird sources; the remaining 715 (20.7%) did not have a source that could be assigned with a probability of greater than 0.95. Compared to ruminant sources, cases attributed to poultry sources were typically among adults (odds ratio (OR) = 1.497, 95% confidence intervals (CIs) = 1.211, 1.852), not among males (OR = 0.834, 95% CIs = 0.712, 0.977), in areas with population density of greater than 500 people/km(2) (OR = 1.213, 95% CIs = 1.030, 1.431), reported in the winter (OR = 1.272, 95% CIs = 1.067, 1.517) and had undertaken recent overseas travel (OR = 1.618, 95% CIs = 1.056, 2.481). The poultry assigned strains had a similar epidemiology to the unassigned strains, with the exception of a significantly higher likelihood of reporting overseas travel in unassigned strains.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions:&lt;/b&gt; Rather than estimate relative risks for acquiring infection, our analyses show that individuals acquire C. jejuni infection from different sources have different associated risk factors. By enhancing our ability to identify at-risk groups and the times at which these groups are likely to be at risk, this work allows public health messages to be targeted more effectively. The rapidly increasing capacity to conduct genetic typing of pathogens makes such traced epidemiological analysis more accessible and has the potential to substantially enhance epidemiological risk factor studies

Rearrangement, amplification, and assortment of mitochondrial DNA molecules in cultured cells of Brassica campestris

We compared Brassica campestris mitochondrial and chloroplast DNAs from whole plants and from a 2-year-old cell culture. No differences were observed in the chloroplast DNAs (cpDNAs), whereas the culture mitochondrial DNA (mtDNA) was extensively altered. Hybridization analysis revealed that the alterations are due entirely to rearrangement. At least two inversions and one large duplication are found in the culture mtDNA. The duplication element is shown to have the usual properties of a plant mtDNA high frequency “recombination repeat”. The culture mtDNA exists as a complex heterogeneous population of rearranged and unrearranged molecules. Some of the culture-associated rearranged molecules are present in low levels in native plant tissue and appear to have sorted out and amplified in the culture. Other mtDNA rearrangements may have occurred de novo. In addition to alterations of the main mitochondrial genome, an 11.3 kb linear mtDNA plasmid present in whole plants is absent from the culture. Contrary to findings in cultured cells of other plants, small circular mtDNA molecules were not detected in the B. campestris cell culture.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46005/1/122_2004_Article_BF00292310.pd