Morten Andersen

Future sea-level rise from Greenland/'s main outlet glaciers in a warming climate

Over the past decade, ice loss from the Greenland Ice Sheet increased as a result of both increased surface melting and ice discharge to the ocean. The latter is controlled by the acceleration of ice flow and subsequent thinning of fast-flowing marine-terminating outlet glaciers. Quantifying the future dynamic contribution of such glaciers to sea-level rise (SLR) remains a major challenge because outlet glacier dynamics are poorly understood. Here we present a glacier flow model that includes a fully dynamic treatment of marine termini. We use this model to simulate behaviour of four major marine-terminating outlet glaciers, which collectively drain about 22 per cent of the Greenland Ice Sheet. Using atmospheric and oceanic forcing from a mid-range future warming scenario that predicts warming by 2.8 degrees Celsius by 2100, we project a contribution of 19 to 30 millimetres to SLR from these glaciers by 2200. This contribution is largely (80 per cent) dynamic in origin and is caused by several episodic retreats past overdeepenings in outlet glacier troughs. After initial increases, however, dynamic losses from these four outlets remain relatively constant and contribute to SLR individually at rates of about 0.01 to 0.06 millimetres per year. These rates correspond to ice fluxes that are less than twice those of the late 1990s, well below previous upper bounds. For a more extreme future warming scenario (warming by 4.5 degrees Celsius by 2100), the projected losses increase by more than 50 per cent, producing a cumulative SLR of 29 to 49 millimetres by 2200.

Step‐wise changes in glacier flow speed coincide with calving and glacial earthquakes at Helheim Glacier, Greenland

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Sudden increase in tidal response linked to calving and acceleration at a large Greenland outlet glacier

[1] Large calving events at Greenland’s largest outlet glaciers are associated with glacial earthquakes and near‐ instantaneous increases in glacier flow speed. At some glaciers and ice streams, flow is also modulated in a regular way by ocean tidal forcing at the terminus. At Helheim Glacier, analysis of geodetic data shows decimeter‐level periodic position variations in response to tidal forcing. However, we also observe transient increases of more than 100% in the glacier’s responsiveness to such tidal forcing following glacial‐earthquake calving events. The timing and amplitude of the changes correlate strongly with the step‐like increases in glacier speed and longitudinal strain rate associated with glacial earthquakes. The enhanced response to the ocean tides may be explained by a temporary disruption of the subglacial drainage system and a concomitant reduction of the friction at the ice‐bedrock interface, and suggests a new means by which geodetic data may be used to infer glacier properties. Citation: de Juan, J., et al. (2010), Sudden increase in tidal response linked to calving and acceleration at a large Greenland outlet glacier, Geophys. Res. Lett., 37, L12501,

Archaeal rRNA Operons, Intron Splicing and Homing Endonucleases, RNA Polymerase Operons and Phylogeny

Summary Over the past decade our laboratory has had a strong interest in defining the phylogenetic status of the archaea. This has involved determining and analysing the sequences of operons of both rRNAs and RNA polymerases and it led to the discovery of the first archaeal rRNA intron. What follows is a description of some recent experiments and an appraisal of the significance of the earlier work.

Educational intervention on medication reviews aiming to reduce acute healthcare consumption in elderly patients with potentially inappropriate medicines—A pragmatic open‐label cluster‐randomized controlled trial in primary care

Potentially inappropriate medicines (PIMs) may cause 10% of unplanned admissions in elderly people. We performed an educational intervention in primary care to reduce acute health care consumption and PIMs through the promotion of medication reviews (MRs) in elderly patients.

Spontaneous reports of drug-induced erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis in Denmark 1968-1991.

Spontaneous reporting systems (SRS) have been established to monitor drug safety problems after marketing, especially rare, but serious adverse drug reactions (ADRs). Among these are the skin disorders erythema multiforme (EM), Stevens– Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). The purpose of this study has been to evaluate the data on these serious skin disorders available in a SRS. All reports concerning these diseases submitted to the Danish Committee on ADRs during the period 1968 to 1991 were reviewed according to predefined criteria. Information was often scarce,and the diagnosis of the reporter had to be accepted at face value in 28% of cases. Two hundred cases of EM, 74 of SJS and 29 of TEN were identified. More than 60% of cases were hospitalized. The diseases had fatal outcome in six patients with TEN, three with SJS and a single patient suffering from EM. One hundred and twenty‐eight different drugs were reported as causal agents. Major drug groups involved were antibiotics (sulphonamides and penicillins), non‐steroidal anti‐inflammatory drugs, anti‐epileptics and analgesics. Incidence estimates based on spontaneous reports were compared to the incidence according to the literature and data from a nationwide hospital discharge diagnosis register. The reporting fraction for EM and SJS is estimated to 10– 30%, and for TEN to 25– 50%, but the validity of reports is in some cases difficult to assess owing to lack of detail.

Initiation and long-term use of benzodiazepines and Z-drugs in bipolar disorder

Increasing evidence points to the harmful effects of long‐term benzodiazepine treatment. Our objective was to study the incidence of, and predictors for, long‐term use of benzodiazepines and Z‐drugs in bipolar disorder.

General practitioners' and nurses' views on medication reviews and potentially inappropriate medicines in elderly patients - a qualitative study of reports by educating pharmacists

Abstract Objective: The aim with this study was to understand more about how general practitioners (GPs) and nurses in primary care experience their work with medication reviews in elderly patients. Design: This qualitative study was nested within a cluster randomised trial and analysed narrative and unstructured diaries written by two pharmacists who performed academic detailing, i.e. educational outreach visits in primary care. The educational sessions dealt with potentially inappropriate medicines, and stimulated interprofessional dialogue in relation to medication reviews. The purpose of the diaries was to document and structure the pedagogical process of academic detailing and contained quotes from 194 GP and 113 nurse participants in the sessions, and the pharmacists’ reflections. The data was explored using thematic analysis. Setting: Thirty-three primary care practices in Stockholm, Sweden. Subjects: GPs and nurses working in primary care. Main outcome measures: Thematic descriptions of academic detailing by pharmacists. Results: Five themes were identified: 1) Complexity in 3 ‘P’: patients, pharmacotherapy, and primary care; 2) What, when, who? Clash between GPs’ and nurses’ experiences and guidelines; 3) Real-world problems and less-than-ideal solutions; 4) Eureka? Experiences with different steps during a medication review; and 5) Threats to GP autonomy. Conclusion: GPs and nurses should participate in the construction and release of guidelines in order to increase their usability in clinical practice. Future research should analyse if alternative strategies such as condensed medical reviews and feedback on prescribing are easier to implement in primary care. Key points Complex medication reviews have been introduced on a large scale in Swedish primary care, but knowledge on GPs’ and nurses’ views on such reviews is lacking. In the context of primary care alternative strategies such as condensed medication reviews and feedback on prescribing may be more applicable than medication reviews according to guidelines. GPs and nurses should make contributions to the development of guidelines on medication reviews in order to increase their usability in clinical practice.

Intercomparison and Validation of SAR-Based Ice Velocity Measurement Techniques within the Greenland Ice Sheet CCI Project

Ice velocity is one of the products associated with the Ice Sheets Essential Climate Variable. This paper describes the intercomparison and validation of ice-velocity measurements carried out by several international research groups within the European Space Agency Greenland Ice Sheet Climate Change Initiative project, based on space-borne Synthetic Aperture Radar (SAR) data. The goal of this activity was to survey the best SAR-based measurement and error characterization approaches currently in practice. To this end, four experiments were carried out, related to different processing techniques and scenarios, namely differential SAR interferometry, multi aperture SAR interferometry and offset-tracking of incoherent as well as of partially-coherent data. For each task, participants were provided with common datasets covering areas located on the Greenland ice-sheet margin and asked to provide mean velocity maps, quality characterization and a description of processing algorithms and parameters. The results were then intercompared and validated against GPS data, revealing in several cases significant differences in terms of coverage and accuracy. The algorithmic steps and parameters influencing the coverage, accuracy and spatial resolution of the measurements are discussed in detail for each technique, as well as the consistency between quality parameters and validation results. This allows several recommendations to be formulated, in particular concerning procedures which can reduce the impact of analyst decisions, and which are often found to be the cause of sub-optimal algorithm performance.

Prevalence of renally inappropriate medicines in older people with renal impairment - A cross-sectional register-based study in a large primary care population

The aim of this population‐based, cross‐sectional study was to analyse the prevalence of renally inappropriate medicines (RIMs) in older people with renal impairment. We included 30 372 people aged ≥65 years with chronic kidney disease (CKD) stage 3, and 2161 with stage 4 attending primary care in Stockholm, Sweden. We used data derived from SCREAM, a database linking patient‐specific data on demography, morbidity, healthcare consumption and dispensed drugs to creatinine measurements. Estimated glomerular filtration rate was calculated with CKD‐EPI based on the first non‐hospital serum creatinine in 2010. RIMs were defined as medicines needing dose adjustment or being contra‐indicated in CKD stage 3 or 4 with reference to Swedish “Janusmed Drugs and Renal function.” Dispensed prescription drugs were analysed during 1 year after creatinine assessment. Drug doses were considered as excessive if their mean volume dispensed per day exceeded the recommended dose. Contra‐indicated medicines were regarded as inappropriate if dispensed at least once during 1 year. Excessive dosing was present in 42.5% of older people with CKD stage 3 and in 58.1% with stage 4. The prevalence of contra‐indicated medicines was 9.4% and 38.0%, respectively. A limited number of RIMs accounted for the majority of excessive dosing, such as drugs acting on the renin‐angiotensin‐aldosterone system, betablockers and opioids. Commonly dispensed contra‐indicated substances were NSAIDs and antidiabetics. We conclude that the prevalence of RIMs in older people with renal impairment is considerably high. Still, RIM use may be manageable as only a limited number of RIMs are frequently used.