Control of sedimentation by active tectonics, glaciation and contourite-depositing currents in Endurance Basin, South Georgia

Endurance Basin is an elongate broadly WNW-ESE trending basin located on the northern margin of the Scotia Sea, adjacent to the southern margin of the South Georgia micro-continent. Bathymetric and TOPAS sub-bottom profile data acquired in 2010 by the British research ship RRS James Clark Ross map this basin and its sedimentology for the first time. Endurance Basin contains a number of sub-basins and a substantial glaciogenic fan. The northern margin of Endurance Basin is formed by a series of steep slopes and intervening troughs. These are interpreted as a left-stepping en echelon array of oblique, strike-slip faults whilst the sub-basins are separated by compressional dip-slip faults. It appears that South Georgia is moving NW with respect to the basin. We interpret five seismic facies from TOPAS data, which are associated with distinct sedimentologies. The most striking units in the basin fill are: substantial contourite drifts located in the NW of the basin and on its southern margin; and two distinct mass transport deposits that pond in the centre of the basin. Combined with the known regional oceanographic setting, the contourites provide evidence of broadly eastward flowing bottom currents, entering the basin from at least two locations. Although landslide scars are present on the steep northern basin margin, the imaged mass transport deposits are interpreted to have been sourced from the glaciogenic fan, located in the SE of the basin, and from a contourite unit located on the basin’s southern margin. Sediments from these events are transported at least 40 km. The contourite drift sequence is at least 100 m thick in the west of the basin and may contain a palaeoenvironmental archive of Antarctic Cirumpolar Current (ACC) flow and the climate of South Georgia extending to the Pliocene. Such an archive would allow reconstruction of ACC flow through the Pleistocene glaciations and provide a means of linking ocean circulation and climate records in the sub-Antarctic Polar Front region

Structural basis for complement factor H-linked age-related macular degeneration

This is the final version of the article. Available from the publisher via the DOI in this record.Nearly 50 million people worldwide suffer from age-related macular degeneration (AMD), which causes severe loss of central vision. A single-nucleotide polymorphism in the gene for the complement regulator factor H (FH), which causes a Tyr-to-His substitution at position 402, is linked to approximately 50% of attributable risks for AMD. We present the crystal structure of the region of FH containing the polymorphic amino acid His402 in complex with an analogue of the glycosaminoglycans (GAGs) that localize the complement regulator on the cell surface. The structure demonstrates direct coordination of ligand by the disease-associated polymorphic residue, providing a molecular explanation of the genetic observation. This glycan-binding site occupies the center of an extended interaction groove on the regulator's surface, implying multivalent binding of sulfated GAGs. This finding is confirmed by structure-based site-directed mutagenesis, nuclear magnetic resonance-monitored binding experiments performed for both H402 and Y402 variants with this and another model GAG, and analysis of an extended GAG-FH complex.B. Prosser is funded by the Wellcome Trust Structural Biology Training Program (075415/Z/04/Z). S. Johnson and P. Roversi were funded by grants to S.M. Lea from the Medical Research Council (MRC) of the United Kingdom (grants G0400389 and G0400775). D. Uhrin and P.N. Barlow were funded by the Wellcome Trust (078780/ Z/05/Z). S.J. Clark was funded by an MRC Doctoral Training Account (G78/7925), and R.B. Sim and A.J. Day were funded by MRC core funding to the MRC Immunochemistry Unit

Low-cost UAV surveys of hurricane damage in Dominica: automated processing with co-registration of pre-hurricane imagery for change analysis

In 2017, hurricane Maria caused unprecedented damage and fatalities on the Caribbean island of Dominica. In order to ‘build back better’ and to learn from the processes causing the damage, it is important to quickly document, evaluate and map changes, both in Dominica and in other high-risk countries. This paper presents an innovative and relatively low-cost and rapid workflow for accurately quantifying geomorphological changes in the aftermath of a natural disaster. We used unmanned aerial vehicle (UAV) surveys to collect aerial imagery from 44 hurricane-affected key sites on Dominica. We processed the imagery using structure from motion (SfM) as well as a purpose-built Python script for automated processing, enabling rapid data turnaround. We also compared the data to an earlier UAV survey undertaken shortly before hurricane Maria and established ways to co-register the imagery, in order to provide accurate change detection data sets. Consequently, our approach has had to differ considerably from the previous studies that have assessed the accuracy of UAV-derived data in relatively undisturbed settings. This study therefore provides an original contribution to UAV-based research, outlining a robust aerial methodology that is potentially of great value to post-disaster damage surveys and geomorphological change analysis. Our findings can be used (1) to utilise UAV in post-disaster change assessments; (2) to establish ground control points that enable before-and-after change analysis; and (3) to provide baseline data reference points in areas that might undergo future change. We recommend that countries which are at high risk from natural disasters develop capacity for low-cost UAV surveys, building teams that can create pre-disaster baseline surveys, respond within a few hours of a local disaster event and provide aerial photography of use for the damage assessments carried out by local and incoming disaster response teams

A micro-optical module for multi-wavelength addressing of trapped ions

The control of large-scale quantum information processors based on arrays of trapped ions requires a means to route and focus multiple laser beams to each of many trapping sites in parallel. Here, we combine arrays of fibres, 3D laser-written waveguides and diffractive microlenses to demonstrate the principle of a micro-optic interconnect suited to this task. The module is intended for use with an ion microtrap of 3D electrode geometry. It guides ten independent laser beams with unique trajectories to illuminate a pair of spatially separated target points. Three blue and two infrared beams converge to overlap precisely at each desired position. Typical relative crosstalk intensities in the blue are $3.6 \times 10^{-3}$ and the average insertion loss across all channels is $8~$dB. The module occupies $\sim 10^4$ times less volume than a conventional bulk-optic equivalent and is suited to different ion species

Noise-Activated Escape from a Sloshing Potential Well

We treat the noise-activated escape from a one-dimensional potential well of an overdamped particle, to which a periodic force of fixed frequency is applied. We determine the boundary layer behavior, and the physically relevant length scales, near the oscillating well top. We show how stochastic behavior near the well top generalizes the behavior first determined by Kramers, in the case without forcing. Both the case when the forcing dies away in the weak noise limit, and the case when it does not, are examined. We also discuss the relevance of various scaling regimes to recent optical trap experiments.Comment: 9 pages, no figures, REVTeX, expanded versio

Exploration of chronic kidney disease prevalence estimates using new measures of kidney function in the health survey for England

Background: chronic kidney disease (CKD) diagnosis relies on glomerular filtration rate (eGFR) estimation, traditionally using the creatinine-based Modification of Diet in Renal Disease (MDRD) equation. The Chronic Kidney Disease Epidemiology Collaboration (CKDEPI) equation performs better in estimating eGFR and predicting mortality and CKD progression risk. Cystatin C is an alternative glomerular filtration marker less influenced by muscle mass. CKD risk stratification is improved by combining creatinine eGFR with cystatin C and urinary albumin to creatinine ratio (uACR). We aimed to identify the impact of introducing CKDEPI and cystatin C on the estimated prevalence and risk stratification of CKD in England and to describe prevalence and associations of cystatin C.Methods and findings: cross sectional study of 5799 people in the nationally representative 2009 and 2010 Health Surveys for England. Primary outcome measures: prevalence of MDRD, CKDEPI and cystatin C-defined eGFR&lt;60ml/min/1.73m2; prevalence of CKD biomarker combinations (creatinine, cystatin C, uACR). Using CKDEPI instead of MDRD reduced the prevalence of eGFR&lt;60ml/min/1.73m2 from 6.0% (95% CI 5.4–6.6%) to 5.2% (4.7–5.8%) equivalent to around 340,000 fewer individuals in England. Those reclassified as not having CKD evidenced a lower risk profile. Prevalence of cystatin C eGFR&lt;60ml/min/1.73m2 was 7.7% and independently associated with age, lack of qualifications, being an ex-smoker, BMI, hypertension, and albuminuria. Measuring cystatin C in the 3.9% people with CKDEPI-defined eGFR&lt;60ml/min/1.73m2 without albuminuria (CKD Category G3a A1) reclassified about a third into a lower risk group with one of three biomarkers and two thirds into a group with two of three. Measuring cystatin C in the 6.7% people with CKDEPI eGFR &gt;60ml/min/1.73m2 with albuminuria (CKD Category G1-2) reclassified almost a tenth into a higher risk group.Limitations: cross sectional study, single eGFR measure, no measured (‘true’) GFR.Conclusions: introducing the CKDEPI equation and targeted cystatin C measurement reduces estimated CKD prevalence and improves risk stratification<br/

Analysis of the giant genomes of Fritillaria (Liliaceae) indicates that a lack of DNA removal characterizes extreme expansions in genome size.

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Plants exhibit an extraordinary range of genome sizes, varying by > 2000-fold between the smallest and largest recorded values. In the absence of polyploidy, changes in the amount of repetitive DNA (transposable elements and tandem repeats) are primarily responsible for genome size differences between species. However, there is ongoing debate regarding the relative importance of amplification of repetitive DNA versus its deletion in governing genome size. Using data from 454 sequencing, we analysed the most repetitive fraction of some of the largest known genomes for diploid plant species, from members of Fritillaria. We revealed that genomic expansion has not resulted from the recent massive amplification of just a handful of repeat families, as shown in species with smaller genomes. Instead, the bulk of these immense genomes is composed of highly heterogeneous, relatively low-abundance repeat-derived DNA, supporting a scenario where amplified repeats continually accumulate due to infrequent DNA removal. Our results indicate that a lack of deletion and low turnover of repetitive DNA are major contributors to the evolution of extremely large genomes and show that their size cannot simply be accounted for by the activity of a small number of high-abundance repeat families.Thiswork was supported by the Natural Environment ResearchCouncil (grant no. NE/G017 24/1), the Czech Science Fou nda-tion (grant no. P501/12/G090), the AVCR (grant no.RVO:60077344) and a Beatriu de Pinos postdoctoral fellowshipto J.P. (grant no. 2011-A-00292; Catalan Government-E.U. 7thF.P.)

Prevalence of chronic kidney disease in adults in England: comparison of nationally representative cross-sectional surveys from 2003 to 2016

Objectives: To identify recent trends in chronic kidney disease (CKD) prevalence in England and explore their association with changes in sociodemographic, behavioural and clinical factors. Design: Pooled cross-sectional analysis.Setting: Health Survey for England 2003, 2009/2010 combined, and 2016.Participants: 17,663 individuals (aged 16+) living in private households.Primary and secondary outcome measures: Prevalence of estimated glomerular filtration rate (eGFR

MKID development for SuperSpec: an on-chip, mm-wave, filter-bank spectrometer

SuperSpec is an ultra-compact spectrometer-on-a-chip for millimeter and submillimeter wavelength astronomy. Its very small size, wide spectral bandwidth, and highly multiplexed readout will enable construction of powerful multibeam spectrometers for high-redshift observations. The spectrometer consists of a horn-coupled microstrip feedline, a bank of narrow-band superconducting resonator filters that provide spectral selectivity, and Kinetic Inductance Detectors (KIDs) that detect the power admitted by each filter resonator. The design is realized using thin-film lithographic structures on a silicon wafer. The mm-wave microstrip feedline and spectral filters of the first prototype are designed to operate in the band from 195-310 GHz and are fabricated from niobium with at Tc of 9.2K. The KIDs are designed to operate at hundreds of MHz and are fabricated from titanium nitride with a Tc of 2K. Radiation incident on the horn travels along the mm-wave microstrip, passes through the frequency-selective filter, and is finally absorbed by the corresponding KID where it causes a measurable shift in the resonant frequency. In this proceedings, we present the design of the KIDs employed in SuperSpec and the results of initial laboratory testing of a prototype device. We will also briefly describe the ongoing development of a demonstration instrument that will consist of two 500-channel, R=700 spectrometers, one operating in the 1-mm atmospheric window and the other covering the 650 and 850 micron bands.Comment: As submitted, except that "in prep" references have been update