Reactivation of Kamb Ice Stream tributaries triggers century-scale reorganization of Siple Coast ice flow in West Antarctica

Ongoing, centennial-scale flow variability within the Ross ice streams of West Antarctica suggests that the present-day positive mass balance in this region may reverse in the future. Here, we use a three-dimensional ice-sheet model to simulate ice flow in this region over 250 years. The flow responds to changing basal properties, as a subglacial till layer interacts with water transported in an active subglacial hydrological system. We show that a persistent weak bed beneath the tributaries of the dormant Kamb Ice Stream is a source of internal ice-flow instability, which reorganizes all ice streams in this region, leading to a reduced (positive) mass balance within decades and a net loss of ice within two centuries. This hitherto unaccounted for flow variability could raise sea-level by 5mm this century. Better constraints on future sea-level change from this region will require improved estimates of geothermal heat flux and subglacial water transport.This work was carried out with support from the Isaac Newton trust, Cecil H. and Ida M. Green Foundation and Natural Environment Research Council (grants NE/E005950/1 and NE/J005800/1). SFP was supported by the U.S. Department of Energy Office of Science, Biological and Environmental Research program. ST acknowledges support from National Science Foundation (grant #0338295). SPC was supported by funding from the Cryospheric Sciences program of NASA and HAF was supported by funding from NSF (grant ANT-0838885 (Fricker)). The source code for the results presented can be obtained by contacting the corresponding author directlyThis is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/2015GL06578

Computational study of the enhancement of graphene electrodes for use in Li-ion batteries via forming superlattices with transition metal dichalcogenides

This is the final version. Available on open access from the American Chemical Society via the DOI in this record. In our study, we examined nine transition metal dichalcogenide (TMDC)-graphene superlattices as potential Li-ion intercalation electrodes. We determined their voltages, with ScS2-graphene in T- and R-phases showing the highest at around 3 V, while the others ranged from 0 to 1.5 V. Most superlattices exhibited minimal volumetric expansion (5 to 10%), similar to NMC (8%), except for SnS2-T and NiS2-T, which expanded up to nearly 20%. We evaluated their capacities using a stability metric, EIS, and found that ScS2-T, ScS2-R, and TiS2-T could be intercalated up to two Li ions per MX2 unit without decomposing to Li2S, yielding capacities of 306.77 mA h/g for both ScS2 phases and 310.84 mA h/g for TiS2-T, roughly equivalent to LiC2. MoS2-T could accept Li up to a limit of a = 15/16 in LiaMoS2Cb, corresponding to a capacity of 121.29 mA h/g (equivalent to LiC4). Examining the influence of graphene layers on MoS2-T, we observed a voltage decrease and an initial EIS decrease before effectively flat lining, which is due to charge donation to the middle graphene layer, reducing the electron concentration near the TMDC layer. As graphene layers increased, overall volume expansion decreased with Li intercalation, which is attributed to the in-plane expansion changing. Our results underscore the potential of TMDC-graphene superlattices as Li-ion intercalation electrodes, offering low volumetric expansions, high capacities, and a wide voltage range. These superlattices all show an increase in the capacity of the graphene.Engineering and Physical Sciences Research Council (EPSRC

Properties of layered TMDC superlattices for electrodes in Li-ion and Mg-ion batteries

This is the final version. Available on open access from the American Chemical Society via the DOI in this record. In this work, we present a first-principles investigation of the properties of superlattices made from transition metal dichalcogenides for use as electrodes in lithium-ion and magnesium-ion batteries. From a study of 50 pairings, we show that, in general, the volumetric expansion, intercalation voltages, and thermodynamic stability of vdW superlattice structures can be well approximated with the average value of the equivalent property for the component layers. We also found that the band gap can be reduced, improving the conductivity. Thus, we conclude that superlattice construction can be used to improve material properties through the tuning of intercalation voltages toward specific values and by increasing the stability of conversion-susceptible materials. For example, we demonstrate how pairing SnS2 with systems such as MoS2 can change it from a conversion to an intercalation material, thus opening it up for use in intercalation electrodes.Engineering and Physical Sciences Research Council (EPSRC

Comparison of serious inhaler technique errors made by device-naïve patients using three different dry powder inhalers: a randomised, crossover, open-label study

Background: Serious inhaler technique errors can impair drug delivery to the lungs. This randomised, crossover, open-label study evaluated the proportion of patients making predefined serious errors with Pulmojet compared with Diskus and Turbohaler dry powder inhalers. Methods: Patients ≥18 years old with asthma and/or COPD who were current users of an inhaler but naïve to the study devices were assigned to inhaler technique assessment on Pulmojet and either Diskus or Turbohaler in a randomised order. Patients inhaled through empty devices after reading the patient information leaflet. If serious errors potentially affecting dose delivery were recorded, they repeated the inhalations after watching a training video. Inhaler technique was assessed by a trained nurse observer and an electronic inhalation profile recorder. Results: Baseline patient characteristics were similar between randomisation arms for the Pulmojet-Diskus (n = 277) and Pulmojet-Turbohaler (n = 144) comparisons. Non-inferiority in the proportions of patients recording no nurse-observed serious errors was demonstrated for both Pulmojet versus Diskus, and Pulmojet versus Turbohaler; therefore, superiority was tested. Patients were significantly less likely to make ≥1 nurse-observed serious errors using Pulmojet compared with Diskus (odds ratio, 0.31; 95 % CI, 0.19–0.51) or Pulmojet compared with Turbohaler (0.23; 0.12–0.44) after reading the patient information leaflet with additional video instruction, if required. Conclusions These results suggest Pulmojet is easier to learn to use correctly than the Turbohaler or Diskus for current inhaler users switching to a new dry powder inhaler

Comparison of breast and bowel cancer screening uptake patterns in a common cohort of South Asian women in England

Background: Inequalities in uptake of cancer screening by ethnic minority populations are well documented in a number of international studies. However, most studies to date have explored screening uptake for a single cancer only. This paper compares breast and bowel cancer screening uptake for a cohort of South Asian women invited to undertake both, and similarly investigates these women's breast cancer screening behaviour over a period of fifteen years. Methods: Screening data for rounds 1, 2 and 5 (1989-2004) of the NHS breast cancer screening programme and for round 1 of the NHS bowel screening pilot (2000-2002) were obtained for women aged 50-69 resident in the English bowel screening pilot site, Coventry and Warwickshire, who had been invited to undertake breast and bowel cancer screening in the period 2000-2002. Breast and bowel cancer screening uptake levels were calculated and compared using the chi-squared test. Results: 72,566 women were invited to breast and bowel cancer screening after exclusions. Of these, 3,539 were South Asian and 69,027 non-Asian; 18,730 had been invited to mammography over the previous fifteen years (rounds 1 to 5). South Asian women were significantly less likely to undertake both breast and bowel cancer screening; 29.9% (n = 1,057) compared to 59.4% (n = 40,969) for non-Asians (p < 0.001). Women in both groups who consistently chose to undertake breast cancer screening in rounds 1, 2 and 5 were more likely to complete round 1 bowel cancer screening. However, the likelihood of completion of bowel cancer screening was still significantly lower for South Asians; 49.5% vs. 82.3% for non-Asians, p < 0.001. South Asian women who undertook breast cancer screening in only one round were no more likely to complete bowel cancer screening than those who decided against breast cancer screening in all three rounds. In contrast, similar women in the non-Asian population had an increased likelihood of completing the new bowel cancer screening test. The likelihood of continued uptake of mammography after undertaking screening in round 1 differed between South Asian religio-linguistic groups. Noticeably, women in the Muslim population were less likely to continue to participate in mammography than those in other South Asian groups. Conclusions: Culturally appropriate targeted interventions are required to reduce observed disparities in cancer screening uptakes

ARTEMIS: Ab initio restructuring tool enabling the modelling of interface structures (article)

This is the final version. Available on open access from Elsevier via the DOI in this recordThe software associated with this article is located in ORE at: http://hdl.handle.net/10871/121480A program, ARTEMIS, has been developed for the study of interface structures. This software allows for the generation of interfaces by identifying lattice matches between two parent crystal structures. To allow for further exploration of the energetic space of the interface, multiple surface terminations parallel to the Miller plane, interface alignments and intermixings are used to generate sets of potential interfaces for each lattice match. These interface structures can then be used in atomic simulations to determine the most energetically favourable interface. The software reported here can help to both drastically reduce the work of generating and exploring interfaces, and aid in understanding of how the interface structure influences the subsequent properties. Using several test cases, we demonstrate how ARTEMIS can both identify the location of an interface in existing structures, and also predict an optimum interface separation based upon the parents’ atomic structures, which aims to accelerate and inform the study of interface science.Engineering and Physical Sciences Research Council (EPSRC

Enhancing the discovery of rare disease variants through hierarchical modeling

Advances in next-generation sequencing technology are enabling researchers to capture a comprehensive picture of genomic variation across large numbers of individuals with unprecedented levels of efficiency. The main analytic challenge in disease mapping is how to mine the data for rare causal variants among a sea of neutral variation. To achieve this goal, investigators have proposed a number of methods that exploit biological knowledge. In this paper, I propose applying a Bayesian stochastic search variable selection algorithm in this context. My multivariate method is inspired by the combined multivariate and collapsing method. In this proposed method, however, I allow an arbitrary number of different sources of biological knowledge to inform the model as prior distributions in a two-level hierarchical model. This allows rare variants with similar prior distributions to share evidence of association. Using the 1000 Genomes Project single-nucleotide polymorphism data provided by Genetic Analysis Workshop 17, I show that through biologically informative prior distributions, some power can be gained over noninformative prior distributions

Identifying influential regions in extremely rare variants using a fixed-bin approach

In this study, we analyze the Genetic Analysis Workshop 17 data to identify regions of single-nucleotide polymorphisms (SNPs) that exhibit a significant influence on response rate (proportion of subjects with an affirmative affected status), called the affected ratio, among rare variants. Under the null hypothesis, the distribution of rare variants is assumed to be uniform over case (affected) and control (unaffected) subjects. We attempt to pinpoint regions where the composition is significantly different between case and control events, specifically where there are unusually high numbers of rare variants among affected subjects. We focus on private variants, which require a degree of “collapsing” to combine information over several SNPs, to obtain meaningful results. Instead of implementing a gene-based approach, where regions would vary in size and sometimes be too small to achieve a strong enough signal, we implement a fixed-bin approach, with a preset number of SNPs per region, relying on the assumption that proximity and similarity go hand in hand. Through application of 100-SNP and 30-SNP fixed bins, we identify several most influential regions, which later are seen to contain some of the causal SNPs. The 100- and 30-SNP approaches detected seven and three causal SNPs among the most significant regions, respectively, with two overlapping SNPs located in the ELAVL4 gene, reported by both procedures

The Citation Field of Evolutionary Economics

Evolutionary economics has developed into an academic field of its own, institutionalized around, amongst others, the Journal of Evolutionary Economics (JEE). This paper analyzes the way and extent to which evolutionary economics has become an interdisciplinary journal, as its aim was: a journal that is indispensable in the exchange of expert knowledge on topics and using approaches that relate naturally with it. Analyzing citation data for the relevant academic field for the Journal of Evolutionary Economics, we use insights from scientometrics and social network analysis to find that, indeed, the JEE is a central player in this interdisciplinary field aiming mostly at understanding technological and regional dynamics. It does not, however, link firmly with the natural sciences (including biology) nor to management sciences, entrepreneurship, and organization studies. Another journal that could be perceived to have evolutionary acumen, the Journal of Economic Issues, does relate to heterodox economics journals and is relatively more involved in discussing issues of firm and industry organization. The JEE seems most keen to develop theoretical insights