297 research outputs found
Exceptional retreat of Novaya Zemlya's marine-terminating outlet glaciers between 2000 and 2013
Novaya Zemlya (NVZ) has experienced rapid ice loss and accelerated marine-terminating glacier retreat during the past 2 decades. However, it is unknown whether this retreat is exceptional longer term and/or whether it has persisted since 2010. Investigating this is vital, as dynamic thinning may contribute substantially to ice loss from NVZ, but is not currently included in sea level rise predictions. Here, we use remotely sensed data to assess controls on NVZ glacier retreat between 1973/76 and 2015. Glaciers that terminate into lakes or the ocean receded 3.5 times faster than those that terminate on land. Between 2000 and 2013, retreat rates were significantly higher on marine-terminating outlet glaciers than during the previous 27 years, and we observe widespread slowdown in retreat, and even advance, between 2013 and 2015. There were some common patterns in the timing of glacier retreat, but the magnitude varied between individual glaciers. Rapid retreat between 2000 and 2013 corresponds to a period of significantly warmer air temperatures and reduced sea ice concentrations, and to changes in the North Atlantic Oscillation (NAO) and Atlantic Multidecadal Oscillation (AMO). We need to assess the impact of this accelerated retreat on dynamic ice losses from NVZ to accurately quantify its future sea level rise contribution
eBank UK: linking research data, scholarly communication and learning
This paper includes an overview of the changing landscape of scholarly communication and describes outcomes from the innovative eBank UK project, which seeks to build links from e-research through to e-learning. As introduction, the scholarly knowledge cycle is described and the role of digital repositories and aggregator services in linking data-sets from Grid-enabled projects to e-prints through to peer-reviewed articles as resources in portals and Learning Management Systems, are assessed. The development outcomes from the eBank UK project are presented including the distributed information architecture, requirements for common ontologies, data models, metadata schema, open linking technologies, provenance and workflows. Some emerging challenges for the future are presented in conclusion
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Coronary Artery Calcification (CAC) and Post-Trial Cardiovascular Events and Mortality Within the Women's Health Initiative (WHI) Estrogen-Alone Trial.
BackgroundAmong women aged 50 to 59 years at baseline in the Women's Health Initiative (WHI) Estrogen-Alone (E-Alone) trial, randomization to conjugated equine estrogen-alone versus placebo was associated with lower risk of myocardial infarction and mortality, and, in an ancillary study, the WHI-CACS (WHI Coronary Artery Calcification Study) with lower CAC, measured by cardiac computed tomography ≈8.7 years after baseline randomization. We hypothesized that higher CAC would be related to post-trial coronary heart disease (CHD), cardiovascular disease (CVD), and total mortality, independent of baseline randomization or risk factors.Methods and resultsWHI-CACS participants (n=1020) were followed ≈8 years from computed tomography scan in 2005 (mean age=64.4) through 2013 for incident CHD (myocardial infarction and fatal CHD, n=17), CVD (n=69), and total mortality (n=55). Incident CHD and CVD analyses excluded women with CVD before scan (n=89). Women with CAC=0 (n=54%) had very low age-adjusted rates/1000 person-years of CHD (0.91), CVD (5.56), and mortality (3.45). In comparison, rates were ≈2-fold higher for women with any CAC (>0). Associations were not modified by baseline randomization to conjugated equine estrogen-alone versus placebo. Adjusted for baseline randomization and risk factors, the hazard ratio (95% confidence interval) for CAC >100 (19%) was 4.06 (2.11, 7.80) for CVD and 2.70 (1.26, 5.79) for mortality.ConclusionsAmong a subset of postmenopausal women aged 50 to 59 years at baseline in the WHI E-Alone Trial, CAC at mean age of 64 years was strongly related to incident CHD, CVD, and to total mortality over ≈8 years, independent of baseline randomization to conjugated equine estrogen-alone versus placebo or CVD risk factors.Clinical trial registrationURL: https://www.clinicaltrials.gov. Unique identifier: NCT00000611
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The effect of the COVID-19 pandemic on disgust sensitivity in a sample of UK adults
The COVID-19 pandemic led to the introduction of a range of infection prevention and control (IPC) measures that resulted in dramatic changes in people’s lives however these IPC measures are not practiced consistently across the population. One predictor of an individual’s responses to the pandemic is disgust sensitivity. Understanding how disgust sensitivity varies within the population could help to inform design of public health messages to promote more uniform behavioral change during future pandemics. To understand the effect of the current COVID-19 pandemic on an individual’s pathogen disgust sensitivity we have compared pathogen disgust sensitivity during the current COVID-19 pandemic to baseline pathogen disgust sensitivity, determined prior to the COVID-19 pandemic, in the same sample of UK adults. We find that the COVID-19 pandemic did not alter overall pathogen disgust sensitivity suggesting that disgust sensitivity is stable despite IPC measures, public health messaging, media coverage and other factors associated with the COVID-19 pandemic
Recent retreat of major outlet glaciers on Novaya Zemlya, Russian Arctic, influenced by fjord geometry and sea-ice conditions
Fabrication of low-cost, large-area prototype Si(Li) detectors for the GAPS experiment
A Si(Li) detector fabrication procedure has been developed with the aim of
satisfying the unique requirements of the GAPS (General Antiparticle
Spectrometer) experiment. Si(Li) detectors are particularly well-suited to the
GAPS detection scheme, in which several planes of detectors act as the target
to slow and capture an incoming antiparticle into an exotic atom, as well as
the spectrometer and tracker to measure the resulting decay X-rays and
annihilation products. These detectors must provide the absorption depth,
energy resolution, tracking efficiency, and active area necessary for this
technique, all within the significant temperature, power, and cost constraints
of an Antarctic long-duration balloon flight. We report here on the fabrication
and performance of prototype 2"-diameter, 1-1.25 mm-thick, single-strip Si(Li)
detectors that provide the necessary X-ray energy resolution of 4 keV for
a cost per unit area that is far below that of previously-acquired commercial
detectors. This fabrication procedure is currently being optimized for the
4"-diameter, 2.5 mm-thick, multi-strip geometry that will be used for the GAPS
flight detectors.Comment: Accepted for publication at Nuclear Instrumentation and Methods A, 12
pages, 11 figure
Exceptional Retreat of Kangerlussuaq Glacier, East Greenland, Between 2016 and 2018
Kangerlussuaq Glacier is one of Greenland’s largest tidewater outlet glaciers, accounting for approximately 5% of all ice discharge from the Greenland ice sheet. In 2018 the Kangerlussuaq ice front reached its most retreated position since observations began in 1932. We determine the relationship between retreat and: (i) ice velocity; and (ii) surface elevation change, to assess the impact of the retreat on the glacier trunk. Between 2016 and 2018 the glacier retreated ∼5 km and brought the Kangerlussuaq ice front into a major (∼15 km long) overdeepening. Coincident with this retreat, the glacier thinned as a result of near-terminus acceleration in ice flow. The subglacial topography means that 2016–2018 terminus recession is likely to trigger a series of feedbacks between retreat, thinning, and glacier acceleration, leading to a rapid and high-magnitude increase in discharge and sea level rise contribution. Dynamic thinning may continue until the glacier reaches the upward sloping bed ∼10 km inland of its current position. Incorporating these non-linear processes into prognostic models of the ice sheet to 2100 and beyond will be critical for accurate forecasting of the ice sheet’s contribution to sea level rise
Ice front change of marine-terminating outlet glaciers in northwest and southeast Greenland during the 21st century
The increasingly negative mass balance of the Greenland ice sheet (GrIS) over the last ~25 years has been associated with enhanced surface melt and increased ice loss from marine-terminating outlet glaciers. Accelerated retreat during 2000–2010 was concentrated in the southeast and northwest sectors of the ice sheet; however, there was considerable spatial and temporal variability in the timing and magnitude of retreat both within and between these regions. This behaviour has yet to be quantified and compared for all glaciers in both regions. Furthermore, it is unclear whether retreat has continued after 2010 in the northwest, and whether the documented slowdown in the southeast post-2005 has been sustained. Here, we compare spatial and temporal patterns of frontal change in the northwest and southeast GrIS, for the period 2000–2015. Our results show near-ubiquitous retreat of outlet glaciers across both regions for the study period; however, the timing and magnitude of inter-annual frontal position change is largely asynchronous. We also find that since 2010, there is continued terminus retreat in the northwest, which contrasts with considerable inter-annual variability in the southeast. Analysis of the role of glacier-specific factors demonstrates that fjord and bed geometry are important controls on the timing and magnitude of glacier retreat
Glacial lake outburst floods threaten millions globally
Glacial lake outburst floods (GLOFs) represent a major hazard and can result in significant loss of life. Globally, since 1990, the number and size of glacial lakes has grown rapidly along with downstream population, while socio-economic vulnerability has decreased. Nevertheless, contemporary exposure and vulnerability to GLOFs at the global scale has never been quantified. Here we show that 15 million people globally are exposed to impacts from potential GLOFs. Populations in High Mountains Asia (HMA) are the most exposed and on average live closest to glacial lakes with ~1 million people living within 10 km of a glacial lake. More than half of the globally exposed population are found in just four countries: India, Pakistan, Peru, and China. While HMA has the highest potential for GLOF impacts, we highlight the Andes as a region of concern, with similar potential for GLOF impacts to HMA but comparatively few published research studies
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