Meltwater flow through a rapidly deglaciating glacier and foreland catchment system: Virkisjökull, SE Iceland

Virkisjökull is a rapidly retreating glacier in south-east Iceland. A proglacial lake has formed in the last ten years underlain by buried ice. In this study we estimate water velocities through the glacier, proglacial foreland and proglacial river using tracer tests and continuous meltwater flow measurements. Tracer testing from a glacial moulin to the glacier outlet in September 2013 demonstrated a rapid velocity of 0.58 m s�1. This was comparable to the velocity within the proglacial river, also estimated from tracer testing. A subsequent tracer test from the same glacial moulin under low flow conditions in May 2014 demonstrated a slower velocity of 0.07 m s�1. The glacier outlet river sinks back into the buried ice, and a tracer test from this sink point through the proglacial foreland to the meltwater river beyond the lake indicated a velocity of 0.03 m s�1,suggesting that an ice conduit system within the buried ice is transferring water rapidly beneath the lake. Ground penetrating radar profiles confirm the presence of this buried conduit system. This study provides an example of rapid deglaciation being associated with extensive conduit systems that enable rapid meltwater transfer from glaciers through the proglacial area to meltwater rivers

Preventing male suicide through a psychosocial intervention that provides psychological support and tackles financial difficulties:a mixed method evaluation

BACKGROUND: To help resolve high suicide rates in Bristol, North Somerset and South Gloucestershire, the charity Second Step was commissioned to roll-out the Hope service offering a psychosocial intervention for men, supporting them through acute distress and addressing financial difficulties. This study evaluated the impact of the Hope service on men at risk of suicide experiencing financial and other difficulties. METHODS: Mixed methods study using: (i) a prospective cohort study design to compare depression, suicidal ideation and financial self-efficacy scores of men aged 30–64, referred to the service between October 2018 and July 2020, at baseline and 6 months follow-up and between low and moderate to high-intensity service users; and (ii) a qualitative interview study to evaluate the acceptability and impact of the Hope service to Hope service users. RESULTS: There was a 49% reduction in depression score (mean reduction − 10.0, 95% CI − 11.7 to − 8.3) and in the proportion of service users with suicidal ideation (percent reduction − 52.5, 95% CI − 64.1% to − 40.9%) at 6 months follow-up compared to baseline. Financial self-efficacy scores increased by 26% (mean increase 2.9, 95% CI 1.8 to 3.9). Qualitative accounts illustrated how ‘Hope saved my life’ for several men interviewed; most respondents described being able to move forward and tackle challenges with more confidence following the Hope intervention. Professional advice to tackle financial and other difficulties such as housing helped to relieve anxiety and stress and enable practical issues to be resolved. CONCLUSIONS: The Hope service offered practical and emotional support to men who have experienced suicidal feelings, redundancy, homelessness and poverty and occupies an important space between mental health and social care provision. Hope demonstrates the value of an intervention which cuts across traditional boundaries between psychiatric care and social advice agencies to provide, what is, in effect, an integrated care service. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-022-03973-5

The geomorphology of Svínafellsjökull and Virkisjökull-Falljökull glacier forelands, southeast Iceland

A detailed, 1:10,500-scale, surficial geology and glacial geomorphology map of Svínafellsjökull and Virkisjökull-Falljökull glacier forelands in southeast Iceland depicts the landsystem imprint of Holocene glacier fluctuations, volcanogenic outburst floods and recent (post-1990) climate-induced rapid ice-front retreat. The map is based on field survey data in combination with 2012 airborne LiDAR data, 2009–2012 terrestrial LiDAR data and 2007 colour aerial photography. The base digital elevation model (DEM) is compiled from an ice-cap wide airborne LiDAR dataset. The mapped glacial landforms are dominated by sequences of recessional moraines laid down in the mid-Holocene, the Little Ice Age, and the last ∼100 years; the state of landform preservation generally decreasing with age. Interspersed with glaciofluvial sedimentation associated with typical ice-marginal retreat sequences is key geomorphological evidence of high-magnitude volcanogenic outburst floods (jökulhlaups) associated with the eruptions of Öraefajökull in 1362 and 1727 CE. Ice-front retreat has accelerated since c.2005 leaving a rapidly evolving buried-ice landscape in front of Virkisjökull-Falljökull – including an ice-cored esker, a large ice-floored (supraglacial) lake, and numerous actively forming kettle holes and ice caverns. This map could act as a ‘reference frame’ for geomorphologists studying the temporal evolution of glacial landform-sediment assemblages undergoing rapid change

Production of high levels of poly-3-hydroxybutyrate in plastids of Camelina sativa seeds

Poly-3-hydroxybutyrate (PHB) production in plastids of Camelina sativa seeds was investigated by comparing levels of polymer produced upon transformation of plants with five different binary vectors containing combinations of five seed-specific promoters for expression of transgenes. Genes encoding PHB biosynthetic enzymes were modified at the N-terminus to encode a plastid targeting signal. PHB levels of up to 15% of the mature seed weight were measured in single sacrificed T1 seeds with a genetic construct containing the oleosin and glycinin promoters. A more detailed analysis of the PHB production potential of two of the best performing binary vectors in a Camelina line bred for larger seed size yielded lines containing up to 15% polymer in mature T2 seeds. Transmission electron microscopy showed the presence of distinct granules of PHB in the seeds. PHB production had varying effects on germination, emergence and survival of seedlings. Once true leaves formed, plants grew normally and were able to set seeds. PHB synthesis lowered the total oil but not the protein content of engineered seeds. A change in the oil fatty acid profile was also observed. High molecular weight polymer was produced with weight-averaged molecular weights varying between 600 000 and 1 500 000, depending on the line. Select lines were advanced to later generations yielding a line with 13.7% PHB in T4 seeds. The levels of polymer produced in this study are the highest reported to date in a seed and are an important step forward for commercializing an oilseed-based platform for PHB production

Human tumour-associated cell adhesion protein MN/CA IX: identification of M75 epitope and of the region mediating cell adhesion

MN/CA IX is a cell surface protein, strongly associated with several types of human carcinomas. It exerts activity of carbonic anhydrase and capacity of binding to cell surface receptors. In the present work, we used affinity purified MN/CA IX protein to demonstrate that the cells adhere to immobilized MN/CA IX and that the monoclonal antibody M75 abrogates cell attachment to MN/CA IX. Using synthetic oligopeptides, we identified M75 epitope and located it in the proteoglycan domain, which contains a sixfold tandem repeat of six amino acids GEEDLP. From phage display library of random heptapeptides we identified and chemically synthesized those which compete for the epitope with M75 and inhibit adhesion of cells to MN/CA IX. These heptapeptides might serve as lead compounds for drug design. © 2000 Cancer Research Campaig

Towards a Definitive Measure of Repetitiveness

Unlike in statistical compression, where Shannon’s entropy is a definitive lower bound, no such clear measure exists for the compressibility of repetitive sequences. Since statistical entropy does not capture repetitiveness, ad-hoc measures like the size z of the Lempel–Ziv parse are frequently used to estimate repetitiveness. Recently, a more principled measure, the size γ of the smallest string attractor, was introduced. The measure γ lower bounds all the previous relevant ones (including z), yet length-n strings can be represented and efficiently indexed within space O(γlognγ), which also upper bounds most measures (including z). While γ is certainly a better measure of repetitiveness than z, it is NP-complete to compute, and no o(γlog n) -space representation of strings is known. In this paper, we study a smaller measure, δ≤ γ, which can be computed in linear time. We show that δ better captures the compressibility of repetitive strings. For every length n and every value δ≥ 2, we construct a string such that γ=Ω(δlognδ). Still, we show a representation of any string S in O(δlognδ) space that supports direct access to any character S[i] in time O(lognδ) and finds the occ occurrences of any pattern P[1.m] in time O(mlog n+ occlogεn) for any constant ε> 0. Further, we prove that no o(δlog n) -space representation exists: for every length n and every value 2 ≤ δ≤ n1-ε, we exhibit a string family whose elements can only be encoded in Ω(δlognδ) space. We complete our characterization of δ by showing that, although γ, z, and other repetitiveness measures are always O(δlognδ), for strings of any length n, the smallest context-free grammar can be of size Ω(δlog2n/ log log n). No such separation is known for γ