3,317 research outputs found
Subglacial drainage processes at a High Arctic polythermal valley glacier
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Recent changes in area and thickness of Torngat Mountain glaciers (northern Labrador, Canada)
The Torngat Mountains National Park, northern Labrador, Canada, contains more
than 120 small glaciers: the only remaining glaciers in continental northeast
North America. These small cirque glaciers exist in a unique topo-climatic
setting, experiencing temperate maritime summer conditions yet very cold and
dry winters, and may provide insights into the deglaciation dynamics of
similar small glaciers in temperate mountain settings. Due to their size and
remote location, very little information exists regarding the health of these
glaciers. Just a single study has been published on the contemporary
glaciology of the Torngat Mountains, focusing on net mass balances from 1981
to 1984. This paper addresses the extent to which glaciologically relevant
climate variables have changed in northern Labrador in concert with
20th-century Arctic warming, and how these changes have affected Torngat Mountain
glaciers. Field surveys and remote-sensing analyses were used to measure
regional glacier area loss of 27âŻ% from 1950 to 2005, substantial rates of
ice surface thinning (up to 6âŻmâŻyr<sup>â1</sup>) and volume losses at Abraham,
Hidden, and Minaret glaciers, between 2005 and 2011. Glacier mass balances
appear to be controlled by variations in winter precipitation and,
increasingly, by strong summer and autumn atmospheric warming since the
early 1990s, though further observations are required to fully understand
mass balance sensitivities. This study provides the first comprehensive
contemporary assessment of Labrador glaciers and will inform both regional
impact assessments and syntheses of global glacier mass balance
Forty-seven Years of Research on the Devon Island Ice Cap, Arctic Canada
The Devon Island ice cap has been the subject of scientific study for almost half a century, beginning with the first mass balance measurements in 1961. Research on the ice cap was the first to investigate (1) the role of meltwater in seasonal ice-velocity variations on a polythermal Arctic ice cap, (2) the use of air temperature rather than net radiation as a proxy for the energy driving surface melt, and (3) the influence of the changing frequency of specific synoptic weather configurations on glacier melt and mass balance. Other research has included investigations of ice cap geometry, flow dynamics, and mass balance; ice core analyses for records of past climate and contaminant deposition; and studies of changes in ice cap area and volume and their relationship to surface mass balance and ice dynamics. Current research includes ground studies connected to efforts to calibrate and validate the radar altimeter that will be carried by the European Space Agencyâs (ESA) CryoSat2 satellite, and a major collaborative Canadian International Polar Year (IPY) project focused on the Belcher Glacier, on the northeast side of the ice cap, that examines hydrodynamics of large tidewater glaciers. This paper summarizes our current knowledge of the Devon Island ice cap and identifies some of the outstanding questions that continue to limit our understanding of climate-ice cap interactions in Arctic regions.La calotte glaciaire de lâĂźle Devon fait lâobjet dâune Ă©tude scientifique depuis prĂšs dâun demi-siĂšcle, les premiĂšres mesures du bilan massique remontant Ă 1961. Câest la premiĂšre fois que des travaux de recherche sur la calotte glaciaire permettent de faire enquĂȘte sur 1) le rĂŽle de lâeau de fonte dans les variations caractĂ©risant la vĂ©locitĂ© de la glace dâune calotte glaciaire polytherme de lâArctique; 2) lâutilisation de la tempĂ©rature de lâair au lieu du bilan radiatif en surface en guise dâapproximation pour la fonte superficielle conductrice dâĂ©nergie, et 3) lâinfluence exercĂ©e par la frĂ©quence changeante de configurations climatiques synoptiques spĂ©cifiques sur la fonte du glacier et le bilan massique. Parmi les autres travaux de recherche, notons des enquĂȘtes sur la gĂ©omĂ©trie de la calotte glaciaire, la dynamique des dĂ©bits dâĂ©coulement et le bilan massique; lâanalyse des enregistrements relatifs aux carottes glaciaires en ce qui a trait Ă dâanciens dĂ©pĂŽts climatiques et dĂ©pĂŽts de contaminants; et lâĂ©tude des changements caractĂ©risant lâaire et le volume de la calotte glaciaire de mĂȘme que leur relation par rapport au bilan massique en surface et Ă la dynamique des glaces. Par ailleurs, les travaux de recherche actuels prennent la forme dâĂ©tudes sur le terrain se rapportant aux efforts visant Ă calibrer et Ă valider lâaltimĂštre radar, Ă©tudes qui seront effectuĂ©es par le satellite CryoSat2 de lâAgence spatiale europĂ©enne (ASE), et un projet dâenvergure en collaboration avec lâAnnĂ©e polaire internationale (API) au Canada portant sur le glacier Belcher, du cĂŽtĂ© nord-est de la carotte glaciaire, projet qui examine lâhydrodynamique des gros glaciers de marĂ©e. La prĂ©sente communication rĂ©sume nos connaissances actuelles de la calotte glaciaire de lâĂźle Devon de mĂȘme que certaines des questions en suspens qui continuent de restreindre la façon dont nous comprenons les interactions entre le climat et la calotte glaciaire dans les rĂ©gions arctiques
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Which primary care practitioners have poor human papillomavirus (HPV) knowledge? A step towards informing the development of professional education initiatives
Background: Primary care practitioners (PCP) play key roles in cervical cancer prevention. Human papillomavirus (HPV) knowledge is an important influence on PCPsâ cervical cancer prevention-related behaviours. We investigated HPV knowledge, and associated factors, among general practitioners (GPs) and practice nurses.
Methods: A survey, including factual questions about HPV infection and vaccination, was mailed to GPs and practice nurses in Ireland. Multivariable logistic regression was used to determine which PCPs had low knowledge (questions correctly answered: infection â€5/11; vaccination: â€4/10). Questions least often answered correctly were identified.
Results: 697 PCPs participated. For HPV infection, GPs and practice nurses answered a median of nine and seven questions correctly, respectively (pâ
of PCPs.
Conclusions: There are important limitations in HPV infection and vaccination knowledge among PCPs. By identifying factors associated with poor knowledge, and areas of particular uncertainty, these results can inform development of professional education initiatives thereby ensuring women have access to uniformly high-quality HPV-related information and advice
An investigation into the mechanisms controlling seasonal speedup events at a High Arctic glacier
Seasonal variations in ice motion have been observed at several polythermal ice masses across the High Arctic, including the Greenland Ice Sheet. However, such variations in ice motion and their possible driving mechanisms are rarely incorporated in models of the response of High Arctic ice masses to predicted climate warming. Here we use a three-dimensional finite difference flow model, constrained by field data, to investigate seasonal variations in the distribution of basal sliding at polythermal John Evans Glacier, Ellesmere Island, Canada. Our results suggest that speedups observed at the surface during the melt season result directly from changes in rates of basal motion. They also suggest that stress gradient coupling is ineffective at transmitting basal motion anomalies to the upper part of the glacier, in contrast to findings from an earlier flow line study at the same glacier. We suggest that stress gradient coupling is limited through the effect of high drag imposed by a partially frozen bed and friction induced by valley walls and significant topographic pinning points. Our findings imply that stress gradient coupling may play a limited role in transmitting supraglacially forced basal motion anomalies through Arctic valley and outlet glaciers with complex topographic settings and highlight the importance of dynamically incorporating basal motion into models predicting the response of the Arctic's land ice to climate change
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Scott Polar Research Institute Arctic Airborne Radio-Echo Sounding Datasets: Canadian Arctic 2000
This data set contains radar sounder profiles from the SPRI 100 MHz ice-penetrating radar instrument over Devon and Ellesmere islands in the Canadian Arctic (CA). Along with the radar profile data, the archive includes derived and ancillary data, plus software code produced for acquisition and working up of data. The data were collected under funding from a UK Natural Environment Research Council (NERC) grant (GR3/12469) to Prof. J. A. Dowdeswell. Please consult the 'MetadataCA2000.pdf' file for a detailed description of the dataset and its contents.Funding: The collection of these data was funded by NERC grant GR3/12469 to J.A. Dowdeswell, as well as by grants from the Meteorological Service of Canada (CRYSYS program) to M.J. Sharp. Further funding (to J.A. Dowdeswell) for development of the dataset was provided by the NERC Centre for Polar Observation and Modelling, UK, and the EU SPICE Project
Exploring women's sensory experiences of undergoing colposcopy and related procedures: implications for preparatory sensory information provision
INTRODUCTION: Some women experience distress during colposcopy examinations which is partly related to women's fear, or experience, of pain during the procedure. However, little is known about women's sensory experiences of colposcopy (other than pain) or what might impact on these experiences. The aim of this study was to explore women's sensory experiences of colposcopy and related procedures and identify factors which influenced negative sensory experiences. METHODS: In-depth interviews were conducted with 23 women who had undergone, for the first time, a colposcopy (some with related procedures, including punch biopsies and loop excision) as part of follow-up for abnormal cervical cytology. Interviews were analysed thematically using the Framework Approach to organise the data and identify emerging higher-order themes. RESULTS: Women described a range of sensory experiences including pain or discomfort, cramping, stinging and cold sensations (due to the application of acetic acid to the cervix). Four key themes emerged as important aspects of the overall sensory experience: levels of pain, treatment-specific sensations, anaesthetic-specific sensations and solution-specific sensations. Factors that may influence women having a negative sensory experience were sensory expectations of the procedure(s) and lack of preparatory sensory information. DISCUSSION: Our study provides unique in-depth insight into women's sensory experiences of colposcopy and related procedures and suggests women require more preparatory sensory information. The issues identified as contributing to women having a negative sensory experience may help inform the development of pre-colposcopy information which may better prepare women with abnormal cervical cytology for follow-up examinations
Enhancing malaria control using a computerised management system in southern Africa
BACKGROUND: Malaria control programmes utilising indoor residual spraying are only effective if a high coverage of targeted structures is achieved and an insecticide that is effective against the specific mosquito vector is correctly applied. Ongoing monitoring of spraying operations is essential to assure optimal programme performance and early corrective action, where indicated. METHODS: Successful development and application of a computerised spraying operations management system in Mpumalanga Province, South Africa during 1998 resulted in its adaptation and introduction in neighbouring Maputo Province, southern Mozambique during 2000. The structure and components of this computerised management system are described, and its' operational benefit in southern Mozambique, where community-based spray operators apply intradomiciliary insecticide, are reviewed. CONCLUSIONS: The computerised management system allowed malaria programme management and field supervisors to monitor spraying coverage, insecticide consumption and application rates on an ongoing basis. The system supported a successful transition to community-based spraying, while assuring correct insecticide application and spraying completion according to schedule
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