Northern Sweden Research Articles

Development of Strategies to Reduce Ventilation and Heating Costs in a Swedish Sublevel Caving Mine\u2014a Unique Case of LKAB\u2019s Konsuln Mine

This paper outlines a unique case of the development of strategies to reduce ventilation and heating costs in Konsuln iron ore mine in northern Sweden. The mine, located just south of Luossavaara-Kiirunavaara Aktiebolag’s Kiruna iron ore mine, was developed as a test mine 2018–2020 for the Sustainable Underground Mining (SUM) project. Besides functioning as a test mine, Konsuln also contributes ore production. The existing mine ventilation system was designed for the current production rate of 0.8 million tons per annum (Mtpa). There is a plan to increase this rate to between 1.8 and 3 Mtpa in the future, and this requires the primary fans to be upgraded. Therefore, a study was carried out to determine whether using ventilation on demand (VOD) could avoid this fan upgrade and reduce Konsuln’s ventilation and heating power costs in the future. The study also investigated whether using battery electric vehicles (BEVs) along with VOD or as a standalone strategy could further reduce these power costs. In addition, the study analyzed the suitability of heating power reduction strategies presently or previously used in the Nordic countries and Canada to investigate potential additional strategies to reduce the heating power cost, the largest portion of Konsuln’s ventilation and heating power costs. The study found using VOD can avoid the expensive upgrading of the existing primary fans and reduce Konsuln’s ventilation and heating power costs in the future. Using BEVs can further reduce these costs. Finally, none of the Nordic and Canadian heating power reduction strategies is suitable for Konsuln because they require unique conditions that do not exist in Konsuln.

Structural Controls on Iron Oxide Copper-Gold Mineralization and Related Alteration in a Paleoproterozoic Supracrustal Belt: Insights from the Nautanen Deformation Zone and Surroundings, Northern Sweden

Abstract The Nautanen deformation zone in the Gällivare area of northern Sweden is a highly Cu-mineralized, magnetite-rich, large-scale shear zone with a long-lived (~100 m.y.) deformation, hydrothermal alteration, and mineralization history. This composite structure hosts the Aitik porphyry Cu-Au-Ag ± Mo deposit and several Cu-Au ± Fe ± Ag ± Mo occurrences assigned to the iron oxide copper-gold (IOCG) deposit class. The Nautanen deformation zone was a locus for polyphase deformation and intermittent metasomatic-hydrothermal activity that overprinted middle Orosirian (ca. 1.90–1.88 Ga) continental arc-related volcanic-plutonic rocks. The deformation zone is characterized by intense shearing fabrics that form a series of subvertical to moderately W-dipping, NNW-SSE–trending, first-order shear zones with oblique reverse kinematics and related NNE-SSW–oriented second-order shear zones that control hydrothermal alteration patterns and Cu-Au mineralization. Hydrothermal alteration in the study area formed during several phases. Volcanic-volcaniclastic rocks to the east and west of the Nautanen deformation zone display low to moderately intense, pervasive to selectively pervasive (i.e., patchy zones or bands, disseminations) sericite ± feldspar, amphibole + biotite + magnetite ± tourmaline, and K-feldspar + hematite alteration. Both the amphibole + biotite and K-feldspar + hematite associations occur adjacent to NNW- and NE-oriented deformation zones and are locally associated with minor sulfide. Within the deformation zone, a moderate to intense biotite + amphibole + garnet + magnetite + tourmaline + sericite alteration assemblage is typically associated with chalcopyrite + pyrrhotite + pyrite and forms linear and subparallel, mainly NNW-oriented seams, bands, and zones that locally appear to overprint possibly earlier scapolite + sericite ± feldspar alteration. Late-stage epidote ± quartz ± feldspar alteration (retrograde saussuritization) forms selectively pervasive zones and epidote veinlets across the area and is partly related to brittle faulting. A magnetite-amphibole-biotite–rich, penetrative S1 foliation records shortening during early Svecokarelian-related deformation (D1) and can be related to ca. 1.88 to 1.87 Ga arc accretion processes and basin inversion that overlaps with regional peak metamorphism to near mid-amphibolite facies conditions and a potential initial Cu mineralization event. Folding and repeated shearing along the Nautanen deformation zone can be assigned to a second, late-Svecokarelian deformation event (D2 stage, ca. 1.82–1.79 Ga) taking place at a higher crustal level. This D2 deformation phase is related to late-stage accretionary processes active during a transition to a stage of postorogenic collapse, and it was accompanied by abundant, syntectonic intrusions. D2-related magmatism produced high-temperature and low-pressure conditions and represents a regional magmatic-hydrothermal event that controlled the recrystallization/remobilization of magnetite, biotite, and amphibole. Associated shear zone reactivation during D2 favors the utilization of the Nautanen deformation zone as a fluid conduit, which preferentially controlled the siting and formation of epigenetic Cu-Au mineralization with distinctive IOCG characteristics within second-order shear zones.

Chatbots to Support Mental Wellbeing of People Living in Rural Areas: Can User Groups Contribute to Co-design?

Digital technologies such as chatbots can be used in the field of mental health. In particular, chatbots can be used to support citizens living in sparsely populated areas who face problems such as poor access to mental health services, lack of 24/7 support, barriers to engagement, lack of age appropriate support and reductions in health budgets. The aim of this study was to establish if user groups can design content for a chatbot to support the mental wellbeing of individuals in rural areas. University students and staff, mental health professionals and mental health service users (N = 78 total) were recruited to workshops across Northern Ireland, Ireland, Scotland, Finland and Sweden. The findings revealed that participants wanted a positive chatbot that was able to listen, support, inform and build a rapport with users. Gamification could be used within the chatbot to increase user engagement and retention. Content within the chatbot could include validated mental health scales and appropriate response triggers, such as signposting to external resources should the user disclose potentially harmful information or suicidal intent. Overall, the workshop participants identified user needs which can be transformed into chatbot requirements. Responsible design of mental healthcare chatbots should consider what users want or need, but also what chatbot features artificial intelligence can competently facilitate and which features mental health professionals would endorse.

Adapted Stochastic PV Hosting Capacity Approach for Electric Vehicle Charging Considering Undervoltage

This paper presents a stochastic approach to single-phase and three-phase EV charge hosting capacity for distribution networks. The method includes the two types of uncertainties, aleatory and epistemic, and is developed from an equivalent method that was applied to solar PV hosting capacity estimation. The method is applied to two existing low-voltage networks in Northern Sweden, with six and 83 customers. The lowest background voltage and highest consumption per customer are obtained from measurements. It is shown that both have a big impact on the hosting capacity. The hosting capacity also depends strongly on the charging size, within the range of charging size expected in the near future. The large range in hosting capacity found from this study—between 0% and 100% of customers can simultaneously charge their EV car—means that such hosting capacity studies are needed for each individual distribution network. The highest hosting capacity for the illustrative distribution networks was obtained for the 3.7 kW single-phase and 11 kW three-phase EV charging power.

Densities of the Eurasian Threetoed Woodpecker Picoides tridactylus calculated from sap row surveys are on par with estimates from fixed route bird censusing

Species-specific tracks animals can be an effective way of mapping species that are hard to find even if they are present. We used observations of sap rows on trees to calculate densities of Eurasian Three-toed Woodpeckers Picoides tridactylus. We surveyed 14 fixed routes in northern Sweden below the montane forest for sap rows during the autumn of 2020. We used our observations of fresh sap rows together with average home range and proportion of active territories per year derived from the literature, to calculate large-scale woodpecker population density. The density based on sap rows was 0.19 pairs per km2. Densities from fixed route bird observations for different parts of Västerbotten County below the montane forests were 0.13–0.14 pairs per km2, in relative agreement with the estimates from sap rows. We also calculated the population density from fixed route observations in the montane forests, and these were almost three times higher. Our density calculations correspond to 7,900 pairs in Västerbotten County. These results indicate that systematic counts of sap rows can quickly provide credible population density estimates of Eurasian Three-toed Woodpeckers.

Long-term fate of nitrogen fixation in Pleurozium schreberi Brid (Mit.) moss carpets in boreal forests

Feather mosses and associated cyanobacteria serve as an important source of nitrogen (N) in boreal forests; however, few studies have effectively traced the N2 fixation in-situ for more than one year. The purpose of this study was to assess the long-term fate of N2 fixed in feather moss carpets in boreal forests of northern Sweden. We conducted a seven-year 15N2(g) labelling and tracing experiment in a boreal forest with a moss bottom layer dominated by Pleurozium schreberi Brid (Mitt). Mesocosms of forest floor with and without mosses present were exposed to a 10% 15N2(g) atmosphere for five days after which samples of moss, shrub, pine seedling and O horizon were taken at varied intervals and analysed for δ15N. Plots were split and burned in year seven to assess the effect of fire on liberating moss N for uptake by Scots pine (Pinus sylvestris L.) seedlings. Feather mosses treated with 15N2(g) were highly enriched in 15N one month after labelling which subsequently declined after seven years to 13% of the original 15N enrichment in green tissue. No measurable 15N enrichment was observed in shrubs or the O horizon in the presence of labelled mosses until greater than five years after the labelling experiment. Fire can liberate moss N, but we did not observe a direct effect of fire on N uptake by pine seedlings. This long-term study indicates that N2 fixed by cyanobacteria in feather moss carpets is conserved in moss tissue for extended periods and slowly transferred to the forest soil O horizon as moss tissue decomposes suggesting that moss N2 fixation is most important as an ecosystem N source at long time scales.

Health Dialogue Experiences of Students, Teachers and School Nurses in Swedish Health-promoting Schools

According to Swedish law, all students are to be offered health dialogues with a school nurse, which helps to promote students’ health literacy. However, research shows that the health dialogues are not being used to their fullest potential. To explore how health dialogues are experienced by school actors – students, teachers and school nurses. The 93 participants from 14 municipalities in northern Sweden wrote open letters sharing their experiences with health dialogues. Phenomenological analysis resulted in two themes with three sub-themes each that describe well-functioning health-promoting schools in which health promotion was seen as a shared practice among staff. In contrast, the participants expressed frustration or resignation with the challenges connected to health dialogues. When given a voice, school actors paint an informative collective picture of health dialogues. Based on our findings, we argue that health dialogues can \promote students' health literacy and enable collaboration between different actors within educational systems. Furthermore, promoting health in school must be viewed as a common assignment for all school staff, and support from school leadership is needed to systematically use the results from health dialogues to inform effective health promotion practice.

“Something You Just Don’t Talk About”: An Analysis of Teenage Boys’ Experiences of Non-Consensual Sexting in Lower Secondary School

The current study explores Swedish teenage boys’ exposure to non-consensual sexting, drawing on interviews with ninth-grade students, age 14 to 15 years, in a lower secondary school in northern Sweden. The results reveal that boys are exposed to unsolicited “dick pics,” unsolicited “female nudes” and non-consensual “explicit video” sharing via the social media platform Snapchat. However, traditional notions of heteronormativity and heterosexual masculinity prevented boys from talking about, understanding and handling experiences that may be identified as digital sexual harassment. Additionally, because of traditional gendered perceptions, students had difficulty categorizing victims and perpetrators of sexting. The study shows that there is a link between male vulnerability and male loneliness that can be manifested in both an individual and collective sense.

The impact of community-based prevention on quality of life-The necessity to control for general health trends the Northern Sweden MONICA study in 2014.

BackgroundThe Västerbotten intervention program (VIP), is a public health promotion program in northern Sweden with the aim of preventing cardiovascular disease. Positive effects have been reported although the evidence is not unequivocal. Since only historical controls have been used, effects from other sources than the program have largely been uncontrolled for and health related quality of life (HRQoL) has not been evaluated.PurposeBy using the neighbouring county of Norrbotten (NB) as the reference population, we compare HRQoL in Västerbotten (VB) and in NB.MethodsIn 2014 the Northern Sweden survey, Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA), examined a random sample from the two counties. HRQoL was measured with the EQ-5D-3L. In total, 1112 subjects aged 40–74 years participated, 516 in VB and 594 in NB. Differences in mean QoL between VB and NB were analysed via Student’s t-test and the Pearson chi-square test.ResultsAverage HRQoL measured by the EQ-5D-index was 0.798 in VB and 0.811 in NB, a difference of 0.013 (p = 0.2, CI -0.009 to 0.036). For subjects aged 45–54 years, the HRQoL was lower in VB than in NB, a difference of 0.048 (p = 0.041; CI 0.002 to 0.0094). Men had higher HRQoL than women, and university educated had higher HRQoL than those without university education. EQ-VAS showed similar results. Subjects from NB and from VB did not differ regarding age, gender and level of education. In NB, HRQoL decrease with age, a pattern not seen in VB.ConclusionsWe found similar levels of HRQoL in VB and in NB.

The utility of bulk wood density for tree-ring research

Bulk wood density measurements are recognized for their utility in ecology, industry, and biomass estimations. In tree-ring research, microdensitometric techniques are widely used, but their ability to determine the correct central tendency has been questioned. Though rarely used, it may be possible to use bulk wood density as a tool to check the accuracy of and even correct microdensitometric measurements. Since measuring bulk wood density in parallel with X-ray densitometry is quickly and easily done, we suspect that its omission is largely due to a lack of awareness of the procedure and/or its importance. In this study, we describe a simple protocol for measuring bulk wood density tailored for tree-ring researchers and demonstrate a few possible applications. To implement real-world examples of the applications, we used a sample of existing X-ray and Blue Intensity (BI) measurements from 127 living and dead Pinus sylvestris trees from northern Sweden to produce new measurements of bulk wood density.We can confirm that the central tendency in this sample material is offset using X-ray densitometry and that the diagnosis and correction of X-ray density is easily done using bulk wood density in linear transfer functions. However, this approach was not suitable for our BI measurements due to heavy discoloration. Nevertheless, we were able to use bulk wood density to diagnose and improve the use of deltaBI (latewood BI – earlywood BI) with regard to its overall trends and multi-centennial variability in a dendroclimatological application. Moreover, we experimented with percent of latewood width, scaled with bulk wood density, as a time- and cost-effective proxy for annual ring density. Although our reconstruction only explains about half of the variation in ring density, it is most likely superior to using fixed literature values of density in allometric equations aimed at biomass estimations.With this study, we hope to raise new awareness regarding the versatility and importance of bulk wood density for dendrochronology by demonstrating its simplicity, relevance, and applicability.

Seojeon Byungwon, Jutlandia, and NORMASH: UN's Scandinavian Allies at the Korean War and Beyond (1950s-1960s).

The Korean War (1950–1953) was one of the most calamitous and brutal wars in modern history. It was fought by the post-colonial people of the peninsula, and it culminated in the creation of two ideologically opposed states, but the three years’ military clash in East Asia (or the Far East) is often labelled simply as a “Forgotten War” in the West including North America. The ensuing ethnic division has been interpreted through the various geopolitical lenses of military strategy, politics, international relations, and power games. What about the situation of casualties? Which particular nations in the United Nations (UN) dispatched medical aid for the treatment of war victims? How did the Scandinavian allies participate the non-European war? What were their unique characteristics among non-military supporting nations? What legacy they left for the post-war Koreans? This paper explores the military-historical backgrounds by which each of the following Northern European nation, namely, Sweden, Denmark, and Norway, decided to send unarmed skilled personnel to aid South Korea. The paper argues the social voluntarism of the neutral group in the critical insight that the field activities of Swedish Seojeon Byungwon, Danish Jutlandia, and Norwegian NORMASH individually promoted the Red Cross spirit of advanced humanitarianism on the top of mandatory duty, in giving special attention on children (orphans), women, civilians, POWs, and medical education, as well as the post-war collaboration for the initial Korean public health system in the 1960s.

Train Performance Analysis Using Heterogeneous Statistical Models

This study investigated the effect of a harsh winter climate on the performance of high-speed passenger trains in northern Sweden. Novel approaches based on heterogeneous statistical models were introduced to analyse the train performance to take time-varying risks of train delays into consideration. Specifically, the stratified Cox model and heterogeneous Markov chain model were used to model primary delays and arrival delays, respectively. Our results showed that weather variables including temperature, humidity, snow depth, and ice/snow precipitation have a significant impact on train performance.

Frost susceptibility of Nordic metal mine tailings

The mining industry produces significant amounts of waste materials, with the greatest volumes generated during enrichment. These waste materials or by-products, tailings, may be used as alternative civil engineering materials, reducing the need for natural resources. In cold climates, the frost behaviour of materials is one critical functional requirement in civil engineering applications. The frost behaviour of tailings classified as sand, silty sand, or sandy clayey silt (EN ISO), from four metal mines located in northern Finland and Sweden, was evaluated in this study using basic laboratory characterisation and one-dimensional freezing tests. The laboratory results were compared with existing guidelines on estimating the frost susceptibility of natural soils. Based on grain size distribution, the tailings samples were characterised as non-susceptible or frost-susceptible. Capillary rise values indicated that the frost susceptibility of the samples ranged from negligible to strong. In the one-dimensional frost heave test, measured frost heave after 96 h was 0.1–23.1 mm and calculated segregation potential (SP) was 0–9.7 mm2/Kh. Based on the frost heave test, the frost susceptibility of the samples ranged from low to strong. The results indicated that the finest samples classified as sandy clayey silt (L1−L3) generated the majority measured amount of frost heave and were classified as frost-susceptible material. The coarser tailings samples (K1-K3 and AK1) classified as sand or silty sand were classified non-susceptible, and measured frost heave amounts were low <1.0 mm (after 96 h). Thus, the tailings samples behaved like natural soils, indicating that classification methods developed for natural soils are valid for evaluation of the frost susceptibility of mine tailings. However, the influence of added reagents should be considered, and standardised frost behaviour methods should be developed.

Low Nitrous Oxide Emissions in a Boreal Spruce Forest Soil, Despite Long-Term Fertilization

Nitrogen (N) fertilization can increase stem wood production by several hundred percent in boreal forests. At the same time, there are concerns about the environmental consequences of N fertilization, especially considering losses of the greenhouse gas nitrous oxide (N2O) to the atmosphere. Soils are a large contributor to N2O emissions on a global scale. The aim of this study was to investigate the consequences of long-term nutrient optimization fertilization on N2O emissions in a boreal forest in Northern Sweden. Field N2O flux measurements were conducted during 2 years with manual and automatic chambers, as well as gas probes in the snow. The N2O emissions were generally low during the whole period of measurements, both from the control and fertilized plots. The emissions were generally highest during the winters, as well as the variability in the observed values. Overall, N2O emissions from fertilized plots were about twice the control, which could be explained by changes in the soil carbon-to-nitrogen ratio.

No increased cancer risk in male hunters in Northern Sweden after radiation exposure from the Chernobyl Nuclear Power Plant accident

BACKGROUND AND AIM: Male hunters have slightly higher total cancer incidence versus male non-hunters in 9 Swedish counties after the Chernobyl Nuclear Power Plant (NPP) accident in 1986. The aim of this study was to investigate whether the contribution of absorbed dose from the Chernobyl fallout could have influenced the elevated cancer incidence, given that hunters have a higher internal radiation exposure due to consumption of game contaminated with ¹³⁷Cs. METHODS: An algorithm was developed to calculate the total absorbed colon dose as a sum of external and internal absorbed colon dose. The time-integrated total absorbed colon dose was calculated individually for hunters (n=40 874) 1986-2015. Allowing for a 5-year latency period, the age-adjusted Incidence Rate Ratios (IRR) per milliGray (mGy) with 95% Confidence Intervals (CI) were calculated using Poisson regression for the follow-up period 1991-2015. A total of 8 964 cancer cases occurred in the hunter cohort to 31 December 2015. Pre-Chernobyl total cancer incidence in each of the counties was investigated as a potential confounding factor. RESULTS:The mean colon dose was 2.39 mGy with more than half of the absorbed colon dose from internal ¹³⁴Cs and ¹³⁷Cs taken together. No specific cancer site showed a significant increased IRR per mGy. For total cancer the IRR per mGy was 0.995 (95% CI 0.988-1.003). The IRR did not change after adjustment for the pre-Chernobyl total cancer incidence. CONCLUSIONS:Using the total colon dose as proxy for the whole body dose, no dose-dependent increased risk for cancer was observed in hunters, hence the elevated cancer incidence in hunters versus non-hunters could probably not be attributed to intake of ¹³⁷Cs contaminated game after the Chernobyl NPP accident. Future analyses will calculate individual organ absorbed dose and investigate dose-response relationship for those cancer sites. KEYWORDS: incidence, ionizing radiation, environmental epidemiology, exposure assessment, cancer and cancer precursors

Modelling the effects of forest management intensification on base cation concentrations in soil water and on tree growth in spruce forests in Sweden

The study investigated the effects of forest residue extraction on tree growth and base cations concentrations in soil water under different climatic conditions in Sweden. For this purpose, the dynamic model ForSAFE was used to compare the effects of whole-tree harvesting and stem harvesting on tree biomass and the soil solution over time at 6 different forest sites. The study confirmed the results from experimental sites showing a temporary reduction of base cation concentration in the soil solution for a period of 20–30 years after whole-tree harvesting. The model showed that this was mainly caused by the reduced inputs of organic material after residue extraction and thereby reduced nutrient mineralisation in the soil. The model results also showed that whole-tree harvesting can affect tree growth at nitrogen-poor forest sites, such as the ones in northern Sweden, due to the decrease of nitrogen availability after residue removal. Possible ways of reducing this impact could be to compensate the losses with fertilisation or extract residue without foliage in areas of Sweden with low nitrogen deposition. The study highlighted the need to better understand the medium- and long-term effects of whole-tree harvesting on tree growth, since the results suggested that reduced tree growth after whole-tree harvesting could be only temporary. However, these results do not account for prolonged extraction of forest residues that could progressively deplete nutrient pools and lead to permanent effects on tree growth.

Characterization of forestry contractors’ business models and profitability in Northern Sweden

ABSTRACT Forestry contractors have doubled their share of work in Swedish forests since the 1990s and have thus become important actors in the industry’s supply chain. Yet, their profitability has often been low. It is essential for a firm’s success to have a well-functioning business model. Therefore, the aim of this study was to characterize business models currently used by forestry contractors and identify differences in the contractors’ financial performance in relation to a chosen business model. A survey was sent to all limited liability companies in northern Sweden that were registered to carry out logging or silviculture. One hundred and ninety-eight contractors responded, and their financial performance was analysed based on information in financial statements. The study highlights that there are clear differences both within and between contractor categories in relation to several business model components, as well as their financial performance. Logging contractors had the lowest profitability, measured as return on assets, and also a lower solidity and liquidity compared to silvicultural and mixed service contractors. The largest logging contractors tended to have a better and more stable profitability than small ones, although the differences were small and varied between years. However, a negative trend in profitability was identified for all contractor groups.

Are riparian buffers surrounding forestry-impacted streams sufficient to meet key ecological objectives? A Swedish case study

In many national guidelines and policies regarding protection of freshwater systems from stressors associated with forestry, riparian buffer width is a commonly prescribed strategy, typically with no other refinements of protection measures. In Sweden, the Strategic Management Objectives (SMOs) were developed to ensure that riparian buffers that are left after harvesting sustain important ecosystem attributes in aquatic systems, referred to as objectives, namely shading, biodiversity, reduction of sedimentation, and provision of deadwood and food. However, little specification is given on threshold targets or how to manage riparian zones to effectively provide these objectives. In this paper, we evaluated whether existing riparian buffers of different widths along small, recently harvested (<8 years) streams were able to provide proxies of these targeted objectives, and further compared harvested streams to counterparts situated in mature unharvested production forests (reference) in northern and southern Sweden. The influence of buffer width varied with objective and geographic location. In both regions, canopy cover (proxy for shading) increased with riparian width, and riparian deadwood was highest in no buffer sites. Organic matter (OM; proxy for food) was highest in the northern no buffer streams, while in the south OM increased with buffer width. All other parameters tested had no relationship to buffer width. These differing responses even in streams subjected to similar land-use and management within a close vicinity and region, suggest that the contemporary strategy of prescribing fixed buffer widths and/or stating objectives without defined guidelines for what constitutes an effective riparian buffer is insufficient given the large variability of stream ecosystems across small spatial scales. More comprehensive consideration synergistically accounting for site-specificity and land mosaic planning are needed to develop functionally effective buffers that can mitigate forestry impacts on stream ecosystems.

The Molecular Basis of Glucose Galactose Malabsorption in a Large Swedish Pedigree.

Glucose-galactose malabsorption (GGM) is due to mutations in the gene coding for the intestinal sodium glucose cotransporter SGLT1 (SLC5A1). Here we identify the rare variant Gln457Arg (Q457R) in a large pedigree of patients in the Västerbotten County in Northern Sweden with the clinical phenotype of GGM. The functional effect of the Q457R mutation was determined in protein expressed in Xenopus laevis oocytes using biophysical and biochemical methods. The mutant failed to transport the specific SGLT1 sugar analog α-methyl-D-glucopyranoside (αMDG). Q457R SGLT1 was synthesized in amounts comparable to the wild-type (WT) transporter. SGLT1 charge measurements and freeze-fracture electron microscopy demonstrated that the mutant protein was inserted into the plasma membrane. Electrophysiological experiments, both steady-state and presteady-state, demonstrated that the mutant bound sugar with an affinity lower than the WT transporter. Together with our previous studies on Q457C and Q457E mutants, we established that the positive charge on Q457R prevented the translocation of sugar from the outward-facing to inward-facing conformation. This is contrary to other GGM cases where missense mutations caused defects in trafficking SGLT1 to the plasma membrane. Thirteen GGM patients are now added to the pedigree traced back to the late 17th century. The frequency of the Q457R variant in Västerbotten County genomes, 0.0067, is higher than in the general Swedish population, 0.0015, and higher than the general European population, 0.000067. This explains the high number of GGM cases in this region of Sweden.

Thrust faulting in glaciers? Re‐examination of debris bands near the margin of Storglaciären, Sweden

Thrust faulting has been suggested as a viable mechanism of debris transport at many glaciers, often inferred from the presence of up‐glacier dipping bands of debris that emerge at the ice surface to form ridges of basally derived material. However, modelling indicates that the development of thrust faults is mechanically inhibited because stresses are much lower than that required for shear failure, a prerequisite for thrust faulting, and field measurements fail to detect thrust‐related displacement. The mechanism for the emplacement of these ridges that appear at the surface of many polythermal valley glacier termini remains open to question. This study re‐examines the origin of debris ridges on the surface of Storglaciären, a polythermal valley glacier in northern Sweden, using field observations, ice microstructural analyses, sediment grain size analysis, stable isotope composition of the ice, and modelling. We find no evidence of discrete displacement across the debris bands that produce the ridges, nor do we find evidence that folding might be responsible. We propose that the bands originate at the base of the glacier by one of two mechanisms, perhaps in combination: (i) refreezing of meltwater near the thermal transition in basal ice, and (ii) injection into tensile fractures periodically opened at the base due to high fluid pressure and then freezing. In either case, separation from the base occurs due to high fluid pressure and freezing introduces ice below the debris bands, which are then transported forwards due to basal shear and upwards due to longitudinal compression, and revealed by surface ablation.