Umeå University
  • Umeå, Sweden
Recent publications
Plastic disposal and their degraded products in the environment are global concern due to its adverse effects and persistence in nature. To overcome plastic pollution and its impacts on environment, a sustainable bioplastic production using renewable feedstock's, such as algae, are envisioned. In this review, the production of polymer precursors such as polylactic acid, polyhydroxybutyrates, polyhydroxyalkanoates, agar, carrageenan and algi-nate from microalgae and macroalgae through direct conversion and fermentation routes are summarized and discussed. The direct conversion of algal biopolymers without any bioprocess (whole algal biomass used emphasizing zero waste discharge concept) favours economic feasibility. Whereas indirect method uses conversion of algal polymers to monomers after pretreatment followed by bioplastic precursor production by fermentation are emphasized. This review paper also outlines the current state of technological developments in the field of algae-based bioplastic, both in industry and in research, and highlights the creation of novel solutions for green bioplastic production employing algal polymers. Finally, the cost economics of the bioplastic production using algal biopolymers are clearly mentioned with future directions of next level bioplastic production. In this review study, the cost estimation was given at laboratory level bioplastic production using casting methods. Further development of bioplastics at pilot scale level may give clear economic feasibility of production at industry. Here, in this review, we emphasized the overview of algal biopolymers for different bioplastic product development and its economic value and also current industries involved in bioplastic production.
Background: Illegal drug use is a public health concern with far-reaching consequences for people who use them and for society. In Sweden, the reported use of illegal drugs has been growing and the number of drug-induced deaths is among the highest in Europe. The aim of this study was to provide a comprehensive and up-to-date estimation of the societal costs of illegal drug use in Sweden, relying as much as possible on registry and administrative data. Methods: A prevalence-based cost-of-illness study of illegal drug use in Sweden in 2020 was conducted. A societal approach was chosen and included direct costs (such as costs of health care, social services, and the criminal justice system), indirect costs (such as lost productivity due to unemployment and drug-induced death), and intangible costs (such as reduced quality of life among people who use drugs and their family members). Costs were estimated by combining registry, administrative, and survey data with unit cost data. Results: The estimated societal costs of illegal drug use were 3.7 billion euros in 2020. This corresponded to 355 euros per capita and 0.78 % of the gross domestic product. The direct and intangible costs were of similar sizes, each contributing to approximately 40 % of total costs, whereas indirect costs contributed to approximately 20 %. The largest individual cost components were reduced quality of life among people who use drugs and costs of the criminal justice system. Conclusion: Illegal drug use has a negative impact on the societal aim to create good and equitable health in Sweden. The findings call for evidence-based prevention of drug use and treatment for those addicted. It is important to address the co-morbidity of mental ill-health and drug dependence, to develop low-threshold services and measures for early prevention among children and young adults, as well as to evaluate laws and regulations connected to illegal drug use.
The effects of climate change in the Arctic are particularly pronounced since temperatures have risen nearly three to four times as fast as in the rest of the planet. Shifts in climatic patterns enable the expansion of temperature-limited vegetation at a global scale to higher latitudes and elevations. The purpose of this study is to predict the distribution of pine trees ( Pinus sylvestris ) across Fennoscandia by drawing from three distinctive datasets. I ask (i) How will the distribution of pine trees will respond to climate change in the next 50 years? (ii) Which method used to collect data is better at predicting the distribution of pine? Three datasets on pine presence together with environmental data were used to model pine distribution with Generalized Linear Models. The first dataset belongs to the Swedish National Forest Inventory and the second is from a Swedish online portal where citizens report their observations of species. The third was compiled by setting up a network of vegetation plots along an elevation gradient in Sweden and Norway. Current and future environmental data was sourced from the Coupled Model Intercomparison Project. The probability of pine presence in general increased with temperature and decreased with precipitation. Therefore, the model forecasts that pine will expand in distribution to areas of higher elevation. The citizen science dataset was superior in predicting pine distribution due to the large number and the wide spatial distribution of observations. The conservation of the tundra and the unique ecosystem process taking place in this area will be threatened by the encroachment of the evergreen treeline which is driven by climate, and citizen science holds unique importance for wide spatial and temporal ecological research.
The use of reconstituted and frozen left-over botulinum toxin A, for treatment of patients with axillary hyperhidrosis seems to be common practice in healthcare. Thus, the objective of this study was to investigate the efficacy and safety of frozen and thawed versus fresh reconstituted abobotulinum toxin (Dysport ® ) and onabotulinum toxin (Botox ® ) in the treatment of axillary hyperhidrosis. A retrospective study was conducted analysing efficacy and data from pre- and 24 weeks post-treatment questionnaires together with medical records of individuals with moderate to severe axillary hyperhidrosis. The patients had received fresh prepared botulinum toxin A in their right axilla while frozen and thawed botulinum toxin A had been administered in their left axilla. Treatment was conducted at our Hyperhidrosis Clinic, Umeå University Hospital, Sweden 2019–2021. Pre- and post-treatment questionnaires from 106 patients were analysed. The patients were 18 to 55 years old, with a mean age of 30.7 ± 9.9 years. No significant differences in patient-reported variables, Hyperhidrosis Disease Severity Scale and VAS 10-point scale, were found between the different preparations (frozen compared to fresh) for abobotulinum toxin and onabotulinum toxin, before treatment and at 6 months follow-up. Multivariable regression analysis resulted in no significant difference regarding side-effects between the preparations or brands of botulinum toxin. The findings of this study support our clinical experience that both abobotulinum toxin and onabotulinum toxin, reconstituted, frozen and thawed, seem to be as effective and safe as fresh prepared botulinum toxin when treating axillary hyperhidrosis. Our findings indicate that left-over preparations of abo- and onabotulinum toxins, stored and frozen for up to 6 months, is a cost-and time-effective way of handling botulinum toxin for treatment of axillary hyperhidrosis.
Internet platforms enabling the short-term rental of private homes are an increasingly important provider of tourist accommodation and a challenge for urban policy. Airbnb is frequently blamed for encouraging property owners to remove their homes from the permanent housing market, thus contributing to the gentrification and displacement of local residents. Empirical research on this topic has been mostly represented by qualitative or indirect quantitative studies, which focus on changes in housing availability rather than the actual population. In our study, we fill this gap by presenting a study of the city of Stockholm, using two sources of georeferenced data: information on properties offered for rent on the Airbnb platform and micro-data on individuals and properties derived from the national statistical office. We verify whether the high number of apartment rental offers on the Airbnb website contributes to the high number of apartments that became unin-habited during 2012-2016. Using both aspatial and spatial auto-regressive models, we find that the platform expansion does have a significant effect on the number of emptied apartments, and thus conclude that the presence of Airbnb contributes to the process of touristification, understood as the replacement of permanent residents with non-permanent populations. This confirms that when analysing urban population change and the gentrifica-tion process, mobile populations should be considered. Context-aware multiscalar and relational approaches are needed to understand the interrelation between human mobility, housing markets and regulations, and transnational internet platforms.
Introduction The objective of this study was to search existing literature on nerve reconstruction surgery in patients with obstetric brachial plexus palsy to determine whether treatment with supraclavicular exploration and nerve grafting produced better elbow flexion outcomes compared to intercostal nerve transfer. Methods This study was a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Individual Patient Data guidelines. A systematic search was conducted using multiple databases. An ordinal regression model was used to analyze the effect of using supraclavicular exploration and nerve grafting or intercostal nerve on elbow flexion with the two scores measured: elbow flexion Medical Research Council scores and Toronto active movements scale scores for elbow flexion. Results A final patient database from 6 published articles consisted of 83 supraclavicular exploration and nerve grafting patients (73 patients with Medical Research Council and 10 patients with Toronto score) and 7 published articles which consisted of 131 intercostal nerve patients (84 patients with Medical Research Council and 47 patients with Toronto scores). Patients who underwent supraclavicular exploration and nerve grafting presented with an average Medical Research Council score of 3.9 ± 0.72 and an average Toronto score of 6.2 ± 2.2. Patients who underwent intercostal nerve transfer presented with an average Medical Research Council score of 3.9 ± 0.71 and an average Toronto score of 6.4 ± 1.2. There was no statistical difference between supraclavicular exploration and nerve grafting and intercostal nerve transfer when utilizing Medical Research Council elbow flexion scores (ordinal regression: 0.3821, standard error: 0.4590, p = 0.2551) or Toronto Active Movement Scale score for elbow flexion (ordinal regression: 0.7154, standard error: 0.8487, p = 0.2188). Conclusion Regardless of surgical intervention utilized (supraclavicular exploration and nerve grafting or intercostal nerve transfers), patients had excellent outcomes for elbow flexion following obstetric brachial plexus palsy when utilizing Medical Research Council or Toronto scores for elbow flexion. The difference between these scores was not statistically significant. Type of study/Level of evidence Therapeutic Study: Investigating the Result of Treatment/level III.
Childhood-onset osteoporosis is a rare but clinically significant condition. Studies have shown pathogenic variants in more than 20 different genes as causative for childhood-onset primary osteoporosis. The X-chromosomal PLS3 , encoding Plastin-3, is one of the more recently identified genes. In this study, we describe five new families from four different European countries with PLS3 -related skeletal fragility. The index cases were all hemizygous males presenting with long bone and vertebral body compression fractures. All patients had low lumbar spine bone mineral density (BMD). The age at the first clinical fracture ranged from 1.5 to 13 years old. Three of the identified PLS3 variants were stop-gain variants and two were deletions involving either a part or all exons of the gene. In four families the variant was inherited from the mother. All heterozygous women reported here had normal BMD and no bone fractures. Four patients received bisphosphonate treatment with good results, showing a lumbar spine BMD increment and vertebral body reshaping after 10 months to 2 years of treatment. Our findings expand the genetic spectrum of PLS3 -related osteoporosis. Our report also shows that early treatment with bisphosphonates may influence the disease course and reduce the progression of osteoporosis, highlighting the importance of early diagnosis for prompt intervention and appropriate genetic counseling.
Primary school science teachers provide vague descriptions of students’ engagement in classroom communication. Furthermore, there may be a discrepancy between what science teachers consider important to teach and what is actually taught. The transformation of intentions into teaching often involves lesson plans which require considerable time and effort to construct. Interestingly, expert teachers tend to rely on, for example, teaching strategies, rather than elaborate plans to realize intentions. This case study contributes knowledge about the congruence between intentions, plans and teaching. A grade 6 teacher was followed during her transformation of the science syllabus into teaching, and data were gathered from interviews, documents, and observations. Content analysis and inductive thematic analysis enabled a comparison between intentions and teaching. Results suggest that the comprehensive lesson plan constituted an obstacle, rather than a tool for realizing the main intention of students practicing reasoning in science classes. The discrepancy did not stem from the teacher’s rejection of the curriculum, but rather from a lack of appropriate teaching strategies to allow for greater flexibility as she struggled to cover the curricular content. The results have the potential to be useful for engaging pre-service and in-service teachers in developing flexible teaching strategies and time efficient planning approaches in upper primary science.
All systems rely on inputs and outputs (I/Os) to perceive and interact with their surroundings. In safety-critical systems, it is important to guarantee both the performance and time-predictability of I/O operations. However, with the continued growth of architectural complexity in modern safety-critical systems, satisfying such real-time requirements has become increasingly challenging due to complex I/O transaction paths and extensive hardware contention. In this paper, we present a new NoC-based Predictable I/O system framework (NPRC-I/O) which reduces this contention and ensures the performance and timepredictability of I/O operations. Specifically, NPRC-I/O contains a programmable I/O command controller (NPRC-CC) and a runtime reconfigurable NoC (RNoC), which provides the capability to adjust I/O transaction paths at run-time. Using this flexibility, we construct an end-to-end transmission latency analysis and an optimisation engine that produces configurations for NPRCI/ O and the I/O traffic in a given system. The constructed analysis and optimisation engine guarantee the timing of all hard realtime traffic while reducing the deadline misses of soft real-time traffic and overall transmission latency.
Objectives: Aortic stenosis (AS) is the most prevalent valvular heart disease among adults. The adipocyte-derived hormones, leptin and adiponectin, have profound metabolic actions. We examined whether these adipokines are independently associated with future aortic valve replacement (AVR). Design: In this longitudinal case-control study, we identified 336 cases who had undergone AVR due to AS, and who had previously participated in population-based health surveys. Two referents were matched to each case and leptin and adiponectin concentrations were analysed from stored baseline survey samples. Uni- and multivariable logistic regression analyses were used to estimate the risk of future AVR. An additional cohort was identified for validation including 106 cases with AVR and 212 matched referents. Results: Median age (interquartile range (IQR)) in years at survey was 59.9 (10.4) and at surgery 68.3 (12.7), and 48% were women. An elevated concentration of leptin was not associated with future AVR (odds ratio [95% confidence interval]) (1.10 [0.92-1.32]), although leptin was associated with a higher risk in patients with coronary artery disease (CAD) having more than 5 years between survey and AVR (1.41 [1.08-1.84]). Adiponectin was not associated with higher risk for future AVR (0.95 [0.82-1.11]), although after stratification for age, higher levels were associated with reduced risk for AVR in persons aged ≥60 years at surgery (0.79 [0.64-0.98]). In the validation study, leptin was associated with future AVR whereas adiponectin was not. None of the associations remained significant after adjustment for body mass index (BMI). Conclusions: The adipokine leptin may promote the development of AS.
To understand health and well-being in later life, it is vital to consider the meaning of subjective aging. This study aimed to explore how perceived health, self-perceptions of aging, and participation in social activities relate to each other among older persons in the Bothnia region and Åland islands in Finland. Data were analyzed using Spearman’s and polychoric correlation and multinomial logistic regression analyses. The perceived good health and the younger physical, psychological, and social dimensions of subjective age were found to be associated with each other and with participation in social activities outside one’s home.
Using material distribution-based topology optimization, we optimize the bandpass design of a loudspeaker cabinet targeting low frequencies. The objective is to maximize the loudspeaker’s output power for a single frequency as well as a range of frequencies. To model the loudspeaker’s performance, we combine a linear electromechanical transducer model with a computationally efficient hybrid 2D–3D model for sound propagation. The adjoint variable approach computes the gradients of the objective function with respect to the design variables, and the Method of Moving Asymptotes (MMA) solves the topology optimization problem. To manage intermediate values of the material indicator function, a quadratic penalty is added to the objective function, and a non-linear filter is used to obtain a mesh independent design. By carefully selecting the target frequency range, we can guide the optimization algorithm to successfully generate a loudspeaker design with the required bandpass character. To the best of our knowledge, this study constitutes the first successful attempt to design the interior structure of a loudspeaker cabinet using topology optimization.
Background The immune response has important clinical value in colorectal cancer (CRC) in both prognosis and response to immunotherapy. This study aims to explore tumour immune cell infiltration in relation to clinically well-established molecular markers of CRC. Methods Multiplex immunohistochemistry and multispectral imaging was used to evaluate tumour infiltration of cytotoxic T cells (CD8 ⁺ ), Th1 cells (T-bet ⁺ ), T regulatory cells (FoxP3 ⁺ ), B cells (CD20 ⁺ ), and macrophages (CD68 ⁺ ) in a cohort of 257 CRC patients. Results We found the expected association between higher immune-cell infiltration and microsatellite instability. Also, whereas BRAF -mutated tumours displayed increased immune-cell infiltration compared to BRAF wild-type tumours, the opposite was seen for KRAS -mutated tumours, differences that were most prominent for cytotoxic T cells and Th1 cells. The opposing relationships of BRAF and KRAS mutations with tumour infiltration of cytotoxic T cells was validated in an independent cohort of 608 CRC patients. A positive prognostic importance of cytotoxic T cells was found in wild-type as well as KRAS and BRAF -mutated CRCs in both cohorts. Conclusion A combined evaluation of MSI status, KRAS and BRAF mutational status, and immune infiltration (cytotoxic T cells) may provide important insights to prognosis and response to immunotherapy in CRC.
Introduction The aim of this study was to assess sensitivity, specificity and interrater reliability of phase-contrast MRI (PC-MRI) for diagnosing carotid near-occlusion. Patients and methods Prospective cross-sectional study conducted between 2018 and 2021. We included participants with suspected 50%–100% carotid stenosis on at least one side, all were examined with CT angiography (CTA) and PC-MRI and both ICAs were analyzed. Degree of stenosis on CTA was the reference test. PC-MRI-based blood flow rates in extracranial ICA and intracranial cerebral arteries were assessed. ICA-cerebral blood flow (CBF) ratio was defined as ICA divided by sum of both ICAs and Basilar artery. Results We included 136 participants. The ICAs were 102 < 50% stenosis, 88 conventional ⩾50% stenosis (31 with ⩾70%), 49 near-occlusion, 12 occlusions, 20 unclear cause of small distal ICA on CTA and one excluded. For separation of near-occlusion and conventional stenoses, ICA flow rate and ICA-CBF ratio had the highest area under the curve (AUC; 0.98–0.99) for near-occlusion. ICA-CBF ratio ⩽0.225 was 90% (45/49) sensitive and 99% (188/190) specific for near-occlusion. Inter-rater reliability for this threshold was excellent (kappa 0.98). Specificity was 94% (29/31) for cases with ⩾70% stenosis. PC-MRI had modest performance for separating <50% and conventional ⩾50% stenosis (highest AUC 0.74), and eight (16%) of near-occlusions were not distinguishable from occlusion (no visible flow). Conclusion ICA-CBF ratio ⩽0.225 on PC-MRI is an accurate and reliable method to separate conventional ⩾50% stenosis and near-occlusion that is feasible for routine use. PC-MRI should be considered further as a potential standard method for near-occlusion detection, to be used side-by-side with established modalities as PC-MRI cannot separate other degrees of stenosis.
Objective Previous research indicates that head teachers in Sweden frequently fail to see school lunch as part of the educational activities of a school. This study contributes to an understanding of how head teachers in Sweden perceive and experience current national policy intentions related to school lunch. Design Qualitative inquiry. Setting Ten municipal state schools in Sweden. Method Individual semi-structured interviews were conducted with 10 head teachers responsible for the compulsory education of 6- to 15-year-olds in state schools. Data from digitally recorded and transcribed interviews were thematically analysed. Results Head teachers primarily saw school lunch as a means to ensure pupils were fed and energised. Their focus tended to be on what followed after school lunch in the form of academic performance and mood, rather than the stated intentions of national school meal policy. Head teachers stressed the value of a free and nutritious school lunch for social equality, and the importance of good collaboration with food service managers and school meal personnel, despite the difficulty of achieving this. Conclusion This paper highlights a gap between head teachers’ perspectives with respect to school lunch and official intentions stated in Swedish national school meals policy. The meanings head teachers saw as connected to school lunch were those of social equality and ensuring pupils were fed, rather than the wider potential envisioned by the authorities. This paper identifies factors that affect the possibility of realising national policy intentions for school lunch in Sweden.
The generation of kinetic‐scale flux ropes (KSFRs) is closely related to magnetic reconnection. Both flux ropes and reconnection sites are detected in the magnetosheath and can impact the dynamics upstream of the magnetopause. In this study, using the Magnetospheric Multiscale satellite, 12,623 KSFRs with a scale <20 RCi are statistically studied in the Earth's dayside magnetosheath. It is found that they are mostly generated near the bow shock (BS), and propagate downstream in the magnetosheath. Their quantity significantly increases as the scale decreases, consistent with a flux rope coalescence model. Moreover, the solar wind parameters can control the occurrence rate of KSFRs. They are more easily generated at high Mach number, large proton density, and weak magnetic field strength of the solar wind, similar to the conditions that favor BS reconnection. Our study shows a close connection between KSFR generation and BS reconnection.
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5,956 members
Bjoern O Schroeder
  • Molecular Infection Medicine Sweden (MIMS)/ Molecular Biology
Constantin Felix Urban
  • Department of Clinical Microbiology
Britt Marie Wiberg
  • Department of Psychology
Kesava Priyan Ramasamy
  • Department of Ecology and Environmental Science
Åsa MM Berglund
  • Department of Ecology and Environmental Science
Umeå University, SE-90187, Umeå, Sweden
Head of institution
Hans Adolfsson
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