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Arctic freshwater ecosystems and fish populations are largely shaped by seasonal and long‐term watershed hydrology. In this paper, we hypothesize how changing air temperature and precipitation will alter freeze and thaw processes, hydrology, and instream habitat to assess potential indirect effects, such as the change to the foraging and behavioral ecology, on Arctic fishes, using Broad Whitefish Coregonus nasusas an indicator species. Climate change is expected to continue to alter hydrologic pathways, flow regimes, and, therefore, habitat suitability, connectivity, and availability for fishes. Warming and lengthening of the growing season will likely increase fish growth rates; however, the exceedance of threshold stream temperatures will likely increase physiological stress and alter life histories. We expect these changes to have mixed effects on Arctic subsistence fishes and fisheries. Management and conservation approaches focused on preserving the processes that create heterogeneity in aquatic habitats, genes, and communities will help maintain the resilience of Broad Whitefish and other important subsistence fisheries. Long‐term effects are uncertain, so filling scientific knowledge gaps, such as identifying important habitats or increasing knowledge of abiotic variables in priority watersheds, is key to understanding and potentially mitigating likely impacts to Arctic fishes in a rapidly changing landscape.

Rapid warming in the Arctic is driving permafrost thaw and lake area changes, with implications for wildlife, subsistence living and climate feedbacks. Models suggest that initial permafrost thaw will result in increased lake area, with continued warming and advanced thaw eventually leading to decreased lake area after ~60–150 years. Here, we review data from 139 sites in 57 publications tracking the direction of lake area change. In the discontinuous permafrost zone, the majority of sites exhibit decreasing lake area, whereas in the continuous zone, the number of sites with increasing lake area is similar to the number with decreasing lake area. These trends suggest that lake drainage due to permafrost thaw is occurring sooner than anticipated. Across the northern permafrost zone, lake area trends are unrelated to precipitation trends and, in most regions, lake area change is heterogeneous. Together, these results indicate that the primary driver of lake area change is permafrost thaw, rather than changes in precipitation and/or evapotranspiration. The observed emergence of lake area trends projected to occur no earlier than the mid-twenty-first century indicates that current models do not adequately represent the processes driving permafrost thaw and associated lake drainage.

Lakes constitute 20–40% of Arctic lowlands, the largest surface water fraction of any terrestrial biome. These lakes provide crucial habitat for wildlife, supply water for remote Arctic communities and play an important role in carbon cycling and the regional energy balance. Recent evidence suggests that climate change is shifting these systems towards long-term wetting (lake formation or expansion) or drying. The net direction and cause of these shifts, however, are not well understood. Here, we present evidence for large-scale drying across lake-rich regions of the Arctic over the past two decades (2000–2021), a trend that is correlated with increases in annual air temperature and autumn rain. Given that increasing air temperatures and autumn rain promote permafrost thaw, our results indicate that permafrost thaw is leading to widespread surface water decline, challenging models that do not predict a net decrease in lake area until the mid-twenty-first or twenty-second centuries.

One of the most conspicuous signals of climate change in high‐latitude tundra is the expansion of ice wedge thermokarst pools. These small but abundant water features form rapidly in depressions caused by the melting of ice wedges (i.e., meter‐scale bodies of ice embedded within the top of the permafrost). Pool expansion impacts subsequent thaw rates through a series of complex positive and negative feedbacks which play out over timescales of decades and may accelerate carbon release from the underlying sediments. Although many local observations of ice wedge thermokarst pool expansion have been documented, analyses at continental to pan‐Arctic scales have been rare, hindering efforts to project how strongly this process may impact the global carbon cycle. Here we present one of the most geographically extensive and temporally dense records yet compiled of recent pool expansion, in which changes to pool area from 2008 to 2020 were quantified through satellite‐image analysis at 27 survey areas (measuring 10–35 km2each, or 400 km2in total) dispersed throughout the circumpolar tundra. The results revealed instances of rapid expansion at 44% (±$\pm $15%) of survey areas. Considered alone, the extent of departures from historical mean air temperatures did not account for between site variation in rates of change to pool area. Pool growth was most clearly associated with upland (i.e., hilly) terrain and elevated silt content at soil depths greater than one meter. These findings suggest that, at short time scales, pedologic and geomorphologic conditions may exert greater control on pool dynamics in the warming Arctic than spatial variability in the rate of air temperature increases. Ice wedge thermokarst pools are meter‐scale water features with a distinctive shape that form on the tundra in response to permafrost thaw. They occupy pits in the ground surface caused by the melting of ice wedges, or subsurface ice bodies which form an interconnected network that manifests at the surface as polygonal ground. Ice wedge thermokarst pool growth not only signals permafrost thaw, but also creates feedbacks on subsequent thaw by altering the surface energy balance, which may accelerate carbon release from permafrost‐affected soils. There are many prior observations of pool growth, but they have typically been locally or regionally focused, and circumpolar analyses are rare. We analyzed recent (2008–2020) time series of sub‐meter resolution satellite imagery at 27 survey areas throughout the Arctic to create one of the largest observational records yet of ice wedge thermokarst pool extent. We then analyzed which environmental and meteorological factors have been most strongly associated with recent trends in pool area at the circumpolar scale. Overall, we found evidence for recent pool growth at 44% (±$\pm $15%) of the survey areas. There was no difference in the recent rate of air temperature increase between sites with and without expanding pools. However, sites with ice wedge thermokarst pool expansion were hillier and had more silt‐rich soils than sites with stable or shrinking pools. Decadal‐scale thermokarst pool expansion was observed at 12 (plus or minus 4) of 27 landscapes monitored throughout the ArcticExpanding thermokarst pools were most likely to be found in topographically convex positions within hilly landscapesTrends in air temperature alone were a poor predictor of recent thermokarst pool expansion Decadal‐scale thermokarst pool expansion was observed at 12 (plus or minus 4) of 27 landscapes monitored throughout the Arctic Expanding thermokarst pools were most likely to be found in topographically convex positions within hilly landscapes Trends in air temperature alone were a poor predictor of recent thermokarst pool expansion

The ways in which the companies can go from more low-tech to more high-tech development by technological and marketing upgrading of new products are mentioned. The analysis is based on interview data from 13 Swedish biotechnical and food processing companies.

ABSTRACTThe value of traditional faculty development programmes has been questioned regarding its effectiveness in transforming clinical education. Rather than training faculty separately from their colleagues, the faculty development programme described in this paper presented an opportunity for teams of faculty to improve clinical education by developing tools grounded in medical education research. The five participating teams were interviewed in focus groups at the end of the programme and followed up with emails and phone calls three years after the end of the programme. The interview data were analysed according to conventional content analysis. Immediately after completion of the programme, all teams had managed to implement their tools, and three years later, four were still in use. The study demonstrates that critical success factors for faculty development to transform change in practice included a design focused on a stepwise, longitudinal programme; coaching of teams; management and peer engagement, and programme days that created space for reflection, development, and discussion.

Greenland Ice Sheet mass loss is impacting connected terrestrial and marine hydrologic systems with global consequences. Groundwater is a key component of water cycling in the Arctic, underlying the 1.7e6km2ice sheet and forming offshore freshwater reserves. However, despite its vast extent, the response of Greenland’s groundwater to ongoing ice sheet change is unknown. Here we present in-situ observations of deep groundwater conditions under the Greenland Ice Sheet, obtained in a 651-metre-long proglacial bedrock borehole angled under the ice sheet margin. We find that Greenland’s groundwater system responds rapidly and sensitively to relatively minor ice sheet forcing. Hydraulic head clearly varies over multi-annual, seasonal and diurnal timescales, which we interpret as a response to fluid pressure forcing at the ice/bed interface associated with changes in overlying ice loading and ice sheet hydrology. We find a systematic decline in hydraulic head over the eight-year observational period is linked primarily to ice sheet mass loss. Ongoing and future ice thinning will probably reduce groundwater discharge rates, with potential impacts to submarine freshwater discharge, freshwater delivery to fjords and biogeochemical fluxes in the Arctic.

Every year, numerous environmental disasters and emergencies occur across the globe with far-reaching impacts on human health and the environment. The ability to rapidly assess an environmental emergency to mitigate potential risks and impacts is paramount. However, collating the necessary evidence in the early stages of an emergency to conduct a robust risk assessment is a major challenge. This article presents a methodology developed to help assess the risks and impacts during the early stages of such incidents, primarily to support the European Union Civil Protection Mechanism but also the wider global community in the response to environmental emergencies. An online rapid risk and impact assessment tool has also been developed to promote enhanced collaboration between experts who are working remotely, considering the impact of a disaster on the environment and public health in the short, medium, and long terms. The methodology developed can support the appropriate selection of experts and assets to be deployed to affected regions to ensure that potential public health and environmental risks and impacts are mitigated whenever possible. This methodology will aid defensible decision making, communication, planning, and risk management, and presents a harmonized understanding of the associated impacts of an environmental emergency.

Hydrochemical changes before and after earthquakes have been reported for over 50 years. However, few reports provide sufficient data for an association to be verified statistically. Also, no mechanism has been proposed to explain why hydrochemical changes are observed far from earthquake foci where associated strains are small (<10−8). Here we address these challenges based on time series of multiple hydrochemical parameters from two sites in northern Iceland. We report hydrochemical changes before and after M >5 earthquakes in 2002, 2012, and 2013. The longevity of the time series (10 and 16 years) permits statistical verification of coupling between hydrochemical changes and earthquakes. We used a Student ttest to find significant hydrochemical changes and a binomial test to confirm association with earthquakes. Probable association was confirmed for preseismic changes based on five parameters (Na, Si, K, δ18O, and δ2H) and postseismic changes based on eight parameters (Ca, Na, Si, Cl, F, SO4, δ18O, and δ2H). Using concentration ratios and stable isotope values, we showed that (1) gradual preseismic changes were caused by source mixing, which resulted in a shift from equilibrium and triggered water‐rock interaction; (2) postseismic changes were caused by rapid source mixing; and (3) longer‐term hydrochemical changes were caused by source mixing and mineral growth. Because hydrochemical changes occur at small earthquake‐related strains, we attribute source mixing and water‐rock interaction to microscale fracturing. Because fracture density and size scale inversely, we infer that mixing of nearby sources and water‐rock interaction are feasible responses to small earthquake‐related strains. Changes in groundwater chemistry before and after earthquakes have been reported for over 50 years. However, few studies have been able to prove that the earthquakes caused these changes. Also, no study has explained why these changes are often reported far from where the earthquake occurred. Here we address these challenges based on measurements of groundwater chemistry made at two sites in northern Iceland over time periods of 10 and 16 years. We used statistical methods to prove that the earthquakes caused changes of ground water chemistry both before and after the earthquakes. We showed that changes of groundwater chemistry before earthquakes were caused by slow mixing between different groundwaters, which triggered reactions with the wall rock that changed groundwater chemistry, and that changes of groundwater chemistry after earthquakes were causes by rapid mixing between different groundwaters. That these changes were detected far from where the earthquakes occurred suggests that cracking of the wall rock at a very small scale was all that was needed for mixing of different groundwaters and reactions with the wall rock to occur. Hydrochemistry has been measured on a weekly basis at two sites for 10–16 years in northern IcelandThree M >5 earthquakes were preceded and/or followed by changes of groundwater chemistry at both sitesChemical changes occur far from earthquake foci at small strains and probably reflect source mixing and water‐rock interaction

Topographical changes are of fundamental interest to a wide range of Arctic science disciplines faced with the need to anticipate, monitor, and respond to the effects of climate change, including geohazard management, glaciology, hydrology, permafrost, and ecology. This study demonstrates several geomorphological, cryospheric, and biophysical applications of ArcticDEM – a large collection of publicly available, time-dependent digital elevation models (DEMs) of the Arctic. Our study illustrates ArcticDEM's applicability across different disciplines and five orders of magnitude of elevation derivatives, including measuring volcanic lava flows, ice cauldrons, post-failure landslides, retrogressive thaw slumps, snowdrifts, and tundra vegetation heights. We quantified surface elevation changes in different geological settings and conditions using the time series of ArcticDEM. Following the 2014–2015 Bárðarbunga eruption in Iceland, ArcticDEM analysis mapped the lava flow field, as well as revealed the post-eruptive ice flows and ice cauldron dynamics. The total dense-rock equivalent (DRE) volume of lava flows is estimated to be (1431 ± 2) million m3. Then, we present the aftermath of a landslide in Kinnikinnick, Alaska, yielding a total landslide volume of (400 ± 8) ×103m3and a total area of 0.025 km2. ArcticDEM is further proven useful for studying retrogressive thaw slumps (RTS). The ArcticDEM-mapped RTS profile is validated by ICESat-2 and drone photogrammetry resulting in a standard deviation of 0.5 m. Volume estimates for lake-side and hillslope RTSs range between 40,000 ± 9000 m3and 1,160,000 ± 85,000 m3, highlighting applicability across a range of RTS magnitudes. A case study for mapping tundra snow demonstrates ArcticDEM's potential for identifying high-accumulation, late-lying snow areas. The approach proves effective in quantifying relative snow accumulation rather than absolute values (standard deviation of 0.25 m, bias of −0.41 m, and a correlation coefficient of 0.69 with snow depth estimated by unmanned aerial systems photogrammetry). Furthermore, ArcticDEM data show its feasibility for estimating tundra vegetation heights with a standard deviation of 0.3 m (no bias) and a correlation up to 0.8 compared to the light detection and ranging (LiDAR). The demonstrated capabilities of ArcticDEM will pave the way for the broad and pan-Arctic use of this new data source for many disciplines, especially when combined with other imagery products. The wide range of signals embedded in ArcticDEM underscores the potential challenges in deciphering signals in regions affected by various geological processes and environmental influences.

ABSTRACTVast mosaics of lakes, wetlands, and rivers on the Arctic Coastal Plain give the impression of water surplus. Yet long winters lock freshwater resources in ice, limiting freshwater habitats and water supply for human uses. Increasingly the petroleum industry relies on lakes to build temporary ice roads for winter oil exploration. Permitting water withdrawal for ice roads in Arctic Alaska is dependent on lake depth, ice thickness, and the fish species present. Recent winter warming suggests that more winter water will be available for ice- road construction, yet high interannual variability in ice thickness and summer precipitation complicates habitat impact assessments. To address these concerns, multidisciplinary researchers are working to understand how Arctic freshwater habitats are responding to changes in both climate and water use in northern Alaska. The dynamics of habitat availability and connectivity are being linked to how food webs support fish and waterbirds across diverse freshwater habitats. Moving toward watershed-scale habitat classification coupled with scenario analysis of climate extremes and water withdrawal is increasingly relevant to future resource management decisions in this region. Such progressive refinement in understanding responses to change provides an example of adaptive management focused on ensuring responsible resource development in the Arctic.

The clinical environment has been increasingly acknowledged as an important setting for learning within healthcare professional education. In particular, researchers have highlighted the need to advance the knowledge on the social nature of learning in the workplace setting. The aim of the thesis was to explore workplace learning among undergraduate medical and nursing students. The thesis adopted a socio-cultural perspective on learning and employed a qualitative approach embedded in an interpretative tradition of inquiry. Four consecutive studies were included in the thesis, the first one designed according to qualitative description whereas the other three had an ethnographic approach. Data were collected through individual interviews and field observations. Content analysis and thematic analysis were employed. For the medical students, workplace learning entailed access to a variety of activities in the role of a marginal member of the healthcare team. Medical students demonstrated an adaptive approach to workplace learning. For the nursing students, workplace learning involved being entrusted to hold responsibility for patient care and the need to negotiate their basic values with those of the workplaces. Nursing students showed a hesitant approach to workplace learning. Workplace learning was built upon varying theoretical perspectives of learning in the medical and nursing contexts respectively. The main message in the thesis argued for an upgrading of students as a powerful and active stakeholder in workplace learning, so as not to view students as passive consumers of clinical education.

Here we describe the SweGen data set, a comprehensive map of genetic variation in the Swedish population. These data represent a basic resource for clinical genetics laboratories as well as for sequencing-based association studies by providing information on genetic variant frequencies in a cohort that is well matched to national patient cohorts. To select samples for this study, we first examined the genetic structure of the Swedish population using high-density SNP-array data from a nation-wide cohort of over 10 000 Swedish-born individuals included in the Swedish Twin Registry. A total of 1000 individuals, reflecting a cross-section of the population and capturing the main genetic structure, were selected for whole-genome sequencing. Analysis pipelines were developed for automated alignment, variant calling and quality control of the sequencing data. This resulted in a genome-wide collection of aggregated variant frequencies in the Swedish population that we have made available to the scientific community through the website https://swefreq.nbis.se. A total of 29.2 million single-nucleotide variants and 3.8 million indels were detected in the 1000 samples, with 9.9 million of these variants not present in current databases. Each sample contributed with an average of 7199 individual-specific variants. In addition, an average of 8645 larger structural variants (SVs) were detected per individual, and we demonstrate that the population frequencies of these SVs can be used for efficient filtering analyses. Finally, our results show that the genetic diversity within Sweden is substantial compared with the diversity among continental European populations, underscoring the relevance of establishing a local reference data set.

Arctic coastal watersheds, though rarely monitored, are expected to have increased runoff, as climate models predict more precipitation in the Arctic. This study provides a synthesis of streamflow changes in watersheds of the Alaska Arctic Coastal Plain (AACP) based on available historic discharge data and water balance analysis. A comparison of annual runoff from the Putuligayuk River watershed (471 km2) from the period 1970–1986 (78 ± 24.1 mm/yr) to the period 1999–2015 (122 ± 49.6 mm/yr) shows increasing discharge and interannual variability. From this discontinuous record of 32 years, the three lowest runoff years occurred in 1979, 2007, and 2008, and the three highest runoff years occurred in 2003, 2014, and 2015. Other studied AACP watersheds with shorter discharge records demonstrate similar patterns of dry (2007–2008) and wet (2014–2015) years during common periods of observation. A combination of favorable antecedent surface storage conditions and above‐average precipitation is required to generate large volumes of surface runoff. A strong relationship between climate, surface storage, and runoff inherent to AACP watersheds makes these systems highly responsive to sea ice retreat and hydrological intensification. Our new estimates of freshwater flux from the AACP to the Beaufort Sea and Chukchi Sea account for an observed range of runoff variability and provide baseline data for modeling arctic hydrologic systems. Observations show increased variability in annual runoff from coastal Arctic watersheds in AlaskaIncreased variability is attributed to changes in precipitation and the amount of interannual storageSynthesis of observational data provides an estimate of freshwater flux from the Alaska Arctic to the seas of the Arctic Ocean

Difficulties in obtaining accurate precipitation measurements have limited meaningful hydrologic assessment for over a century due to performance challenges of conventional snowfall and rainfall gauges in windy environments. Here, we compare snowfall observations and bias adjusted snowfall to end‐of‐winter snow accumulation measurements on the ground for 16 years (1999–2014) and assess the implication of precipitation underestimation on the water balance for a low‐gradient tundra wetland near Utqiagvik (formerly Barrow), Alaska (2007–2009). In agreement with other studies, and not accounting for sublimation, conventional snowfall gauges captured 23–56% of end‐of‐winter snow accumulation. Once snowfall and rainfall are bias adjusted, long‐term annual precipitation estimates more than double (from 123 to 274 mm), highlighting the risk of studies using conventional or unadjusted precipitation that dramatically under‐represent water balance components. Applying conventional precipitation information to the water balance analysis produced consistent storage deficits (79 to 152 mm) that were all larger than the largest actual deficit (75 mm), which was observed in the unusually low rainfall summer of 2007. Year‐to‐year variability in adjusted rainfall (±33 mm) was larger than evapotranspiration (±13 mm). Measured interannual variability in partitioning of snow into runoff (29% in 2008 to 68% in 2009) in years with similar end‐of‐winter snow accumulation (180 and 164 mm, respectively) highlights the importance of the previous summer's rainfall (25 and 60 mm, respectively) on spring runoff production. Incorrect representation of precipitation can therefore have major implications for Arctic water budget descriptions that in turn can alter estimates of carbon and energy fluxes. Measuring precipitation is difficult in the Arctic because the region is a windy, cold desert. Most rainfall and snowfall occur in amounts that are often too small to be effectively measured, with a majority of the precipitation falling as snow. Measurement gauges perform poorly in this windy environment with undercatch reaching 400 % for solid precipitation (snow), but performing better for liquid precipitation. Still, engineering and research studies that rely on precipitation measurements, rarely account for this underestimation of water received by the landscape. Too low rainfall and snowfall leads to underestimates of both streamflow and water storage in soils and surface water bodies. This, in turn, can lead to erroneous conclusions in regards to permafrost thaw and greenhouse gas emissions, which is partly how the Arctic plays a major role in affecting the global climate. A simple measurement of the maximum snow depth on the ground at the end of the winter, which anyone can do with a ruler, can be an effective solution to reduce the precipitation underestimation problem and its cascading effects on a myriad of other processes. Water storage deficits are consistently overestimated when precipitation is not adjusted for underestimationEnd‐of‐snowmelt through July rainfall is a more effective measure of drought conditions than total warm season rainfallPrecipitation bias lead to underestimated snowmelt runoff, due to overestimated antecedent water storage deficits and underestimated snowfall

Arctic river discharge has increased in recent decades although sources and mechanisms remain debated. Abundant literature documents permafrost thaw and mountain glacier shrinkage over the past decades. Here we link glacier runoff to aquifer recharge via a losing headwater stream in subarctic Interior Alaska. Field measurements in Jarvis Creek (634 km2), a subbasin of the Tanana and Yukon Rivers, show glacier meltwater runoff as a large component (15–28%) of total annual streamflow despite low glacier cover (3%). About half of annual headwater streamflow is lost to the aquifer (38 to 56%). The estimated long‐term change in glacier‐derived aquifer recharge exceeds the observed increase in Tanana River base flow. Our findings suggest a linkage between glacier wastage, aquifer recharge along the headwater stream corridor, and lowland winter discharge. Accordingly, glacierized headwater streambeds may serve as major aquifer recharge zones in semiarid climates and therefore contributing to year‐round base flow of lowland rivers. Glacier meltwater discharge represents >15% of total annual streamflow in a subarctic headwater with 3% glacier coverageHeadwater streams lose 38 to 56% of annual streamflow to recharge of lowland aquifersGlacier‐derived aquifer recharge via headwater streambeds may explain long‐term increases in lowland river base flow Observations of increased river discharge in summer and winter span the scientific community and Arctic residents. Changes in streamflow present implications for river travel throughout the year and impact sea ice growth and nutrient exports to Arctic Ocean coastal waters. Processes responsible for increasing river discharge are debated because no single process can explain increases in runoff of several rivers. Here we show that the ubiquitous mass loss from subarctic mountain glaciers feeds rivers not only in summer but also in the winter. We measured summer discharge at two places in the same glacier‐fed headwater stream in Interior Alaska and found that the discharge is lower downstream that upstream. The difference represents water that is lost to infiltration into ground and subsequent aquifer recharge. The aquifer in turn feeds the larger lowland river, like the Tanana River, during winter. As such, glaciers across the semiarid regions can be important sources of water to streams and aquifers and an overlooked source of increasing river discharge reported across the Arctic.

Australian students' performance and engagement in mathematics is an ongoing issue. It also found when students were given "now you try one" tasks (a teacher demonstrates something, then asks students to try it), the majority of students engaged in non-thinking behaviours. [Extracted from the article]

The few prethaw observations of tundra carbon fluxes suggest that there may be large spring releases, but little is known about the scale and underlying mechanisms of this phenomenon. To address these questions, we combined ecosystem eddy flux measurements from two towers near Barrow, Alaska, with mechanistic soil‐core thawing experiment. During a 2 week period prior to snowmelt in 2014, large fluxes were measured, reducing net summer uptake of CO2by 46% and adding 6% to cumulative CH4emissions. Emission pulses were linked to unique rain‐on‐snow events enhancing soil cracking. Controlled laboratory experiment revealed that as surface ice thaws, an immediate, large pulse of trapped gases is emitted. These results suggest that the Arctic CO2and CH4spring pulse is a delayed release of biogenic gas production from the previous fall and that the pulse can be large enough to offset a significant fraction of the moderate Arctic tundra carbon sink. Prethaw carbon flux pulses during thaw offset 46% of CO2summer uptake and added 6% to CH4summer fluxesLaboratory experiment linked pulse emissions to a delayed microbial production mechanismThe spring pulse may be a large underrepresented source of carbon in Arctic regions

Ice wedges are common features of the subsurface in permafrost regions. They develop by repeated frost cracking and ice vein growth over hundreds to thousands of years. Ice-wedge formation causes the archetypal polygonal patterns seen in tundra across the Arctic landscape. Here we use field and remote sensing observations to document polygon succession due to ice-wedge degradation and trough development in ten Arctic localities over sub-decadal timescales. Initial thaw drains polygon centres and forms disconnected troughs that hold isolated ponds. Continued ice-wedge melting leads to increased trough connectivity and an overall draining of the landscape. We find that melting at the tops of ice wedges over recent decades and subsequent decimetre-scale ground subsidence is a widespread Arctic phenomenon. Although permafrost temperatures have been increasing gradually, we find that ice-wedge degradation is occurring on sub-decadal timescales. Our hydrological model simulations show that advanced ice-wedge degradation can significantly alter the water balance of lowland tundra by reducing inundation and increasing runoff, in particular due to changes in snow distribution as troughs form. We predict that ice-wedge degradation and the hydrological changes associated with the resulting differential ground subsidence will expand and amplify in rapidly warming permafrost regions.

Based on hydrochemical monitoring, petrological observations, and geochemical modeling, we identify a mechanism and estimate a time scale for fault healing after an earthquake. Hydrochemical monitoring of groundwater samples from an aquifer, which is at an approximate depth of 1200 m, was conducted over a period of 10 years. Groundwater samples have been taken from a borehole (HU‐01) that crosses the Húsavík‐Flatey Fault (HFF) near Húsavík town, northern Iceland. After 10 weeks of sampling, on 16 September 2002, an M5.8 earthquake occurred on the Grimsey Lineament, which is approximately parallel to the HFF. This earthquake caused rupturing of a hydrological barrier resulting in an influx of groundwater from a second aquifer, which was recorded by 15–20% concentration increases for some cations and anions. This was followed by hydrochemical recovery. Based on petrological observations of tectonically exhumed fault rocks, we conclude that hydrochemical recovery recorded fault healing by precipitation of secondary minerals along fractures. Because hydrochemical recovery accelerated with time, we conclude that the growth rate of these minerals was controlled by reaction rates at mineral‐water interfaces. Geochemical modeling confirmed that the secondary minerals which formed along fractures were saturated in the sampled groundwater. Fault healing and therefore hydrochemical recovery was periodically interrupted by refracturing events. Supported by field and petrographic evidence, we conclude that these events were caused by changes of fluid pressure probably coupled with earthquakes. These events became successively smaller as groundwater flux decreased with time. Despite refracturing, hydrochemical recovery reached completion 8–10 years after the earthquake. Hydrochemical monitoring records fault healing after an earthquakeMineral growth along fractures is surface controlledThe time scale of fault healing is 8–10 years

On the Arctic Coastal Plain (ACP) in northern Alaska (USA), permafrost and abundant surface‐water storage define watershed hydrological processes. In the last decades, the ACP landscape experienced extreme climate events and increased lake water withdrawal (LWW) for infrastructure construction, primarily ice roads and industrial operations. However, their potential (combined) effects on streamflow are relatively underexplored. Here, we applied the process‐based, spatially distributed hydrological and thermal Water Balance Simulation Model (10 m spatial resolution) to the 30 km2Crea Creek watershed located on the ACP. The impacts of documented seasonal climate extremes and LWW were evaluated on seasonal runoff (May–August), including minimum 7‐day mean flow (MQ7), the recovery time of MQ7 to pre‐perturbation conditions, and the duration of streamflow conditions that prevents fish passage. Low‐rainfall scenarios (21% of normal, one to three summers in a row) caused a larger reduction in MQ7 (−56% to −69%) than LWW alone (−44% to −58%). Decadal‐long consecutive LWW under average climate conditions resulted in a new equilibrium in low flow and seasonal runoff after 3 years that included a disconnected stream network, a reduced watershed contributing area (54% of total watershed area), and limited fish passage of 20 days (vs. 6 days under control conditions) throughout summer. Our results highlight that, even under current average climatic conditions, LWW is not offset by same‐year snowmelt as currently assumed in land management regulations. Effective land management would therefore benefit from considering the combined impact of climate change and industrial LWWs. Winter lake water withdrawal (LWW) reduces summer low‐ and average streamflow with the recovery time of up to 3 yrWinter LWW is not counterbalanced by same‐year snowmelt recharge as currently assumed in land management regulationsLow rainfall (21% of normal) combined with winter LWW lead to intermittently dry streams in the following three summers Winter lake water withdrawal (LWW) reduces summer low‐ and average streamflow with the recovery time of up to 3 yr Winter LWW is not counterbalanced by same‐year snowmelt recharge as currently assumed in land management regulations Low rainfall (21% of normal) combined with winter LWW lead to intermittently dry streams in the following three summers

The optical properties of isotope-pure 28Si12C, natural SiC and enriched with 13C isotope samples of the 4H polytype are studied by means of Raman and photoluminescence spectroscopies. The phonon energies of the Raman active phonons at the Γ point and the phonons at the M point of the Brillouin zone are experimentally determined. The excitonic bandgaps of the samples are accurately derived using tunable laser excitation and the phonon energies obtained from the photoluminescence spectra. Qualitative comparison with previously reported results on isotope-manipulated Si is presented.

Polycrystalline SiC containing boron and nitrogen are used in growth of fluorescent SiC for white LEDs. Two types of doped polycrystalline SiC have been studied in detail with secondary ion mass spectrometry: sintered SiC and poly-SiC prepared by sublimation in a physical vapor transport setup. The materials are co-doped materials with nitrogen and boron to a concentration of 1x1018 cm-3 and 1x1019 cm-3, respectively. Depth profiles as well as ion images have been recorded. According to ocular inspection, the analyzed poly-SiC consists mainly of 4H-SiC and 6H-SiC grains. In these grains, the boron concentration is higher and the nitrogen concentration is lower in the 6H-SiC compared to the 4H-SiC polytype. No inter-diffusion between grains is observed.

High quality bulk-like 3C-SiC were grown on on-axis (0001) 6H-SiC substrate by sublimation epitaxy. The microwave photoconductivity decay mapping measurements revealed that this material shows considerable long carrier lifetimes varied from 3.519 to 7.834 μs under the injection level of 3.5×1012 cm-2, which are comparable with the best carrier lifetimes in 4H-SiC layers. The mapping of high resolution x-ray diffraction obtained from the same region shows that smaller carrier lifetimes seem to correspond to the larger FWHM values and vice versa. This shows that long carrier lifetime obtained in 3C-SiC is due to the improvement of the crystal quality.

In this paper we present a concept on the defect generation and annihilation during the homoepitaxial growth step of cubic silicon carbide by sublimation epitaxy on templates grown by chemical vapor deposition on silicon substrates. Several structural defects like stacking faults, twins and star defects show opposite evolution from the template layer into the sublimation grown material. While single planar defects tend to annihilate with increasing layer thickness, the defect clusters assigned to the star defects are enlarging. These issues contribute to a balance of how to achieve the best possible quality on thick layers.

Bulk-like 3C-SiC was grown on 1.2 degrees low off-axis 6H-SiC substrates using a sublimation epitaxy technique. The effects of temperature ramp-up and increase in layer thickness on the 3C-SiC domain formation were explored. The temperature ramp-up had no significant effect on the domain size. The domain size was considerably increased and the crystal quality was significantly improved by increasing the thickness of the layer towards bulk-like material. Average full width at half maximum values of 149 arcsec and 65 arcsec were measured in samples with thicknesses of 305 µm and 1080 µm, respectively, at a footprint of 1x3 mm2. This result implies that heteropeitaxial growth of 3C-SiC on low off-axis 6H-SiC substrates by a sublimation method can be used to prepare 3C-SiC seeds or can be further developed for growth of bulk 3C-SiC material.

The growth of homoepitaxial layers on off-oriented 6H-SiC substrates proceeds via step flow growth. Such epilayers can exhibit irregularities like step bunching, splicing or crossover of steps. The effects of the substrate off-orientation and growth temperature show an influence on formation of surface irregularities. The mean features seem to be given by the growth mode competition of two-dimensional growth to the step-flow growth.

Homoepitaxial layers of fluorescent 4H-SiC were grown on 4 degree off-axis substrates by sublimation epitaxy. Luminescence in the green spectral range was obtained by co-doping with nitrogen and boron utilizing donor-acceptor pair luminescence. This concept opens possibilities to explore green light emitting diodes using a new materials platform.

Fluorescent silicon carbide was grown using the fast sublimation growth process on low off-axis 6H-SiC substrates. In this case, the morphology of the epilayer and the incorporation of dopants are influenced by the Si/C ratio. Differently converted tantalum foils were introduced into the growth cell in order to change vapor phase stochiometry during the growth. Fluorescent SiC grown using fresh and fully converted tantalum foils contained morphological instabilities leading to lower room temperature photoluminescence intensity while an improved morphology and optical stability was achieved with partly converted tantalum foil. This work reflects the importance of considering the use of Ta foil in sublimation epitaxy regarding the morphological and optical stability in fluorescent silicon carbide.

Heteroepitaxial growth of 3C-SiC on 0.8 and 1.2 degree off-oriented 6H-SiC substrates was studied using a sublimation growth process. The 3C-SiC layers were grown at high growth rates with layer thickness up to 300 µm. The formation and the quality of 3C-SiC are influenced by the off-orientation of the substrate, the growth temperature (studied temperature range from 1750 oC to 1850oC), and the growth ambient (vacuum at 5*10-5 mbar and nitrogen at 5*10-1 mbar). The largest domains of 3C-SiC and the lowest number of double positioning boundaries were grown using nitrogen ambient and the highest growth temperature. The combined use of low off-axis substrate and high growth rate is a potential method to obtain material with bulk properties.

In this work a new approach for the production of freestanding cubic silicon carbide (3C SiC) in (001) orientation is presented which is based on the combination of chemical vapor deposition (CVD) and the fast sublimation growth process (FSGP). Fast homoepitaxial growth of 3C SiC using sublimation epitaxy on a template created by CVD growth on silicon substrates allows to obtain thick freestanding material with low defect densities. Using standard silicon wafers as substrate material permits a cost efficient process and the applying of wafers with different orientations. The (001) orientation used in this work will potentially allow further heteroepitaxial growth of other cubic semiconductors, like e.g. gallium nitride (GaN).

Growth of 3C or 6H-SiC epilayers on low off-axis 6H-SiC substrates can be mastered by changing the size of the on axis plane formed by long terraces in the epilayer using geometrical control. The desired polytype can be selected in thick (~200 µm) layers of both 6H-SiC and 3C-SiC polytypes on substrates with off-orientation as low as 1.4 and 2 degrees. The resultant crystal quality of the 3C and the 6H-SiC epilayers, grown under the same process parameters, deteriorates when lowering the off-orientation of the substrate.

To investigate the benefits and safety of an intensive muscular training program in patients with chronic polymyositis (PM) and dermatomyositis (DM).Nine patients with chronic PM or DM (median age 53 years, range 44–61) were included. Assessments of impairment (10–15 voluntary repetition maximum [VRM], the Functional Index 2 [FI‐2], the Grippit, and pain rated on the Borg CR‐10 scale), activity limitation (Myositis Activities Profile), and participation restriction (patients' disease impact on well‐being) were performed 4 weeks prior to baseline, at baseline, and after 7 weeks of exercise. A 6‐item core set of disease activity measures was administered and muscle biopsy samples of vastus lateralis were obtained at baseline and after 7 weeks of exercise. Response criteria at an individual level were set for disability and disease activity. The patients exercised 3 days per week for 7 weeks on loads allowing 10 VRM.On a group level there were no significant differences between assessments at 4 weeks before baseline compared with baseline. The group improved significantly regarding 10–15 VRM and FI‐2 at 7 weeks compared with baseline (P < 0.05). All patients were responders with respect to impairment and 2 were activity limitation responders whereas participation restriction remained unchanged in all. Two patients were responders with reduced disease activity and no patient had signs of increased muscle inflammation in the muscle biopsy sample after 7 weeks of exercise.Patients with chronic, stable PM and DM can perform this intensive resistive exercise program with beneficial effects on impairment and activity limitation without increased muscle inflammation.

Dans le cadre d’un traitement d’entretien de 52 semaines chez des adultes atteints de psoriasis en plaques, une association fixe Cal/DB sous forme de mousse a été étudiée versus placebo pour évaluer le délai avant la première rechute, le nombre de rechutes et le nombre de jours en rémission. Il s’agit de la première étude montrant l’efficacité du traitement d’entretien à long terme du psoriasis en plaques avec un traitement topique bihebdomadaire.

Abstract: Hypertension is prevalent, affecting approx 20–25% of the adult population in the Western world. Primary hypertension is a multifactorial, complex disorder where many genes and genetic variants are assumed to interact with environmental factors in order to produce the specific blood pressure level for a given individual. Family and twin studies show that between 30 and 60% of blood pressure variation is determined by genetic factors. Monogenic disorders of hypertension are rare and do not explain blood pressure variability in the population at large. Obvious candidate genes for the study of hypertension are those that encode components of a blood pressure regulating system targeted by an antihypertensive drug, or those that are involved in counterregulatory systems. In this review, we give a brief pathophysiological blackgroud to hypertension and the rational behind utilizing SNP genotyping in the study of hypertension and the antihypertensive response to treatment. We also discuss some of the novel results of pharmacodynamic studies in antihypertensive treatment, an area in its infancy.

Many lives can be saved today thanks to modern resuscitation technology. However, heart-lung resuscitation (HLR) is sometimes used in situations where it is of little or no use to the patient.The aim of this study was to map physicians' experience of situations where they had decided not to resuscitate and to study whether there are any differences in the experience of different groups of physicians. The study was quantitative and the instrument was a questionnaire where data were statistically analysed.The result shows that clinical belonging affects physicians' attitudes and experience and largely determines whether or not they decide to refrain from heart — lung resuscitation. The patients' and their families' wishes as well as the patients' diagnoses, prognoses, and age formed the basis of the physicians' decisions. The anaesthesiologists represented to a lesser degree the view that the nurse should be involved in the decision than the physicians at the medico-geriatric clinic (p=0.006), the gynaecological clinic (p=0.04), and the surgical clinic (p=0.03). Twenty-nine per cent experienced that the patient was involved in the decision to refrain from HLR. The physicians at the surgical clinic represented to a lesser degree the view that the patient took part in the decision than the physicians at the anaesthetic and medico-geriatric clinics (p=0.001 and p=0.05, respectively). Sixty-five per cent experienced that family members took part in the decision to refrain from HLR. More than half of the physicians were of the opinion that the decision-making and the documentation of the decision to refrain from HLR can be improved. Only 29 % were of the opinion that there were clear guidelines regarding where to document the decision. In the study, wishes were expressed that guidelines shared by different clinics should be drawn up.

Our aim was to determine whether the change in left ventricular (LV) mass in response to antihypertensive treatment could be predicted by multivariate analysis of single nucleotide polymorphisms (SNPs) in candidate genes reflecting pathways likely to be involved in blood pressure control.

We aimed to develop a microarray genotyping system for multiplex analysis of a panel of single nucleotide polymorphisms (SNPs) in genes encoding proteins involved in blood pressure regulation, and to apply this system in a pilot study demonstrating its feasibility in the pharmacogenetics of hypertension. A panel of 74 SNPs in 25 genes involved in blood pressure regulation was selected from the SNP databases, and genotyped in DNA samples of 97 hypertensive patients. The patients had been randomized to double-blind treatment with either the angiotensin II type 1 receptor blocker irbesartan or the β1-adrenergic receptor blocker atenolol. Genotyping was performed using a microarray based DNA polymerase assisted ‘minisequencing’ single nucleotide primer extension assay with fluorescence detection. The observed genotypes were related to the blood pressure reduction using stepwise multiple regression analysis. The allele frequencies of the selected SNPs were determined in the Swedish population. The established microarray-based genotyping system was validated and allowed unequivocal multiplex genotyping of the panel of 74 SNPs in every patient. Almost 7200 SNP genotypes were generated in the study. Profiles of four or five SNP-genotypes that may be useful as predictors of blood pressure reduction after antihypertensive treatment were identified. Our results highlight the potential of microarray-based technology for SNP genotyping in pharmacogenetics.

It was hypothesized that the reduction of high-energy phosphates in muscle after repeated sprints is smaller in women than in men. Fifteen healthy and physically active women and men with an average age of 25 yr (range of 19–42 yr) performed three 30-s cycle sprints (Wingate test) with 20 min of rest between sprints. Repeated blood and muscle samples were obtained. Freeze-dried pooled muscle fibers of types I and II were analyzed for high-energy phosphates and their breakdown products and for glycogen. Accumulation of plasma ATP breakdown products, plasma catecholamines, and blood lactate, as well as glycogen reduction in type I fibers, was all lower in women than in men during sprint exercise. Repeated sprints induced smaller reduction of ATP and smaller accumulation of IMP and inosine in women than in men in type II muscle fibers, with no gender differences in changes of ATP and its breakdown products during the bouts of exercise themselves. This indicates that the smaller ATP reduction in women than in men during repeated sprints was created during recovery periods between the sprint exercises and that women possess a faster recovery of ATP via reamination of IMP during these recovery periods.

Arithmetic sequence is used in this study as a means to explore pre-service elementary school teachers’ connections between additive and multiplicative structures as well as several concepts related to introductory number theory. Vergnaud’s theory of conceptual fields is used and refined to analyze students’ attempts to test membership of given numbers and to generate elements that are members of a given infinite arithmetic sequence. Our results indicate that participants made a strong distinction between two types of arithmetic sequences: sequences of multiples (e.g., 7, 14, 21, 28,&) and sequences of ‘non-multiples,’ (e.g., 8, 15, 22, 29,&). Students were more successful in recognizing the underlying structure of elements in sequences of multiples, whereas for sequences of non-multiples students often preferred algebraic computations and were mostly unaware of the invariant structure linking the two types. We examine the development of students’ schemes as they identify differences and similarities in the situations presented to them. Une séquence arithmétique est une séquence de nombres caractérisée par une différence commune entre des paires adjacentes. Dans le cadre de cette étude, nous voulons en savoir plus sur la façon dont les futurs enseignants et enseignantes de l’élémentaire analysent la structure sous-jacente des séquences arithmétiques. La séquence arithmétique est utilisée comme moyen d’analyser, d’une part, les liens que font les futurs enseignants et enseignantes de l’élémentaire entre les structures additives et multiplicatives, et d’autre part, plusieurs concepts liés à l’introduction de la théorie des nombres. On leur aposé les questions suivantes: Quelles stratégies cognitives les élèves utilisent-ils lorsqu’ils sont confrontés à des problèmes nouveaux liés aux séquences arithmétiques? Quels sont les patterns qui sont manifestes aux yeux des élèves dans la structure mathématique des séquences arithmétiques? Quels sont ceux qui ne sont pas reconnus? Comment les élèves appliquent-ils les patterns reconnus à des situations données de résolution de problèmes? Quels sont les outils et les notions mathématiques qu’ils utilisent? Dans quels cas recourent-ils à une approche fondée sur les patterns et dans quels cas préfèrent-ils une approche computationelle? Par quoi leurs choix sont-ils influencés? Cette étude s’inscrit dans le cadre théorique des champs conceptuels de Vergnaud. Un champ conceptuel, dans notre interprétation de Vergnaud (1994, 1996), est un ensemble de concepts, d’opérations et de théorèmes reliés entre eux. Selon la définition de Vergnaud (1996, p. 238), un concept est un triplet formé de trois composantes C = (S,I,S), où S est l’ensemble des situations dans lesquelles ce concept prend une signification, I est l’ensemble des invariants opérationnels qui apparaissent dans les schemes développés pour pouvoir faire face à ces situations, et Sest l’ensemble des représentations symboliques (langage naturel, diagrammes, représentations graphiques, &) qui peuvent être utilisées pour représenter les relations impliquées dans ces situations, communiquer à leur propos et aider à les maîtriser. Vergnaud (1994, p. 58) définit les schèmes comme des systèmes invariants de comportements qui s’appliquent à des classes de problèmes bien définies. Dans cette étude, nous avons réalisé des entrevues cliniques avec de futurs enseignants et enseignantes de l’élémentaire à qui nous avons présenté deux types de situations: (a) la vérification de l’appartenance d’un élément donné à une séquence donnée, par exemple: «360 est-il un élément de la séquence 2,5,8 …?»; (b) la génération d’exemples: «Donnez un exemple de nombre élevé qui soit un élément de la séquence 2, 5,8 &». Nous avons analysé les schèmes dynamiques auxquels font appel les étudiants et étudiantes dans leurs tentatives de résoudre les situations, en particulier pour 1.identifier et décrire les stratégies (ou règles d’action) utilisées lorsque les participants se trouvent devant des situations problématiques liées aux séquences arithmétiques2.analyser les stratégies des étudiants et découvrir les «théorèmes-en-action» sous-jacents3.suggérer une piste pour le développement des schèmes individuels dans le contexte des situations présentées4.analyser le développement des schèmes individuels sous l’angle des relations entre les champs conceptuels des structures multiplicatives, des structures additives et de l’algèbre élémentaire. Nos résultats indiquent que les participants distinguaient nettement deux types de séquences arithmétiques, les séquences de multiples (par exemple 7,14,21,28 &) et les séquences «non multiples» (par exemple 8, 15, 22, 29 …). Il était plus facile pour les étudiants et étudiantes de reconnaître la structure sous-jacente dans les séquences de multiples, tandis que pour les séquences non multiples ils préféraient souvent les computations algébriques et ne percevaient guère la structure invariante qui reliait les deux types. Dans les séquences de multiples, les étudiants et étudiantes reconnaissaient aussi bien les structures additives (différence commune) que multiplicatives (où chaque élément est le multiple d’une différence commune). Dans les séquences non multiples, la majorité n’ont reconnu que la structure additive. Plusieurs incitations ont même été nécessaires pour que certains étudiants et étudiantes perçoivent les séquences non multiples comme des «multiples modifiés» et mettent à profit cet aspect multiplicatif pour exécuter les tâches. Nous analysons le développement des schemes des élèves à mesure qu’ils percevaient les différences et les similarités dans les situations qui leur étaient présentées. En conclusion, le traitement traditionnel des séquences arithmétiques dans l’enseignement néglige à notre avis un aspect important: la structure commune des éléments qu’il y a dans toute séquence. Pour les apprenants et apprenantes en mathématiques, il est essentiel d’accorder une plus grande place à la reconnaissance des patterns et des structures. De plus, une telle attention pourrait s’avérer particulièrement profitable aux futurs enseignants et enseignantes de l’élémentaire, qui, au cours de leur carrière, seront plus probablement appelés à enseigner la reconnaissance des patterns que les manipulations algébriques.