Publikationer från Umeå universitet
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Recent intensified riverine CO2 emission across the Northern Hemisphere permafrost region
No full textGlobal warming causes permafrost thawing, transferring large amounts of soil carbon into rivers, which inevitably accelerates riverine CO2 release. However, temporally and spatially explicit variations of riverine CO2 emissions remain unclear, limiting the assessment of land carbon-climate feedback. Using new and published 5685 riverine CO2 partial pressure data in the Arctic and Tibetan Plateau, we show that current riverine CO2 emission across the Northern Hemisphere permafrost zone is 200 ± 15 Tg C yr⁻1. The emission offsets 28.1 ± 2.1% of the land carbon uptake in the Northern Hemisphere permafrost zone, with large regional variability of 13.1 to 63.1%. Our findings suggest that CO2 emissions increased at a rate of 0.42 ± 0.16 Tg C yr⁻1 during 2000 to 2020, and this is primarily driven by increased precipitation and accelerated permafrost thawing under climate change. This study highlights increased riverine carbon emission and strengthening of the permafrost carbon feedback to climate after incorporating carbon release from rivers
(Re)shaping Ottoman women : the construction of female subjectivities through educational discourse in women’s magazines (1869–1908)
No full textThis paper explores how female subjectivities were constructed in the educational discourse in women’s magazines published in the Ottoman language from the first magazine that was published in 1869 until the promulgation of the Second Constitution Period in 1908 in the Ottoman Empire. The study draws on the concept of Occidentalism defined by Meltem Ahıska, as well as on Deniz Kandiyoti’s concept of patriarchal bargain. These concepts are used to identify and explain central tensions emerging in the Occidentalist fantasy in the educational discourse. I argue that, in the writings on women in women’s magazines of the late Ottoman period, we can see, first, the early traces of the Occidentalist fantasy and, second, how it is channelised to shape Ottoman women’s subjectivities within at least three tensions. I also argue that the ambivalent attitudes of the authors in these Occidentalist tensions operated as strategies for patriarchal bargaining for Ottoman women. Thus, this paper contributes to the understanding of the construction of womanhood in the late Ottoman period by showing the complexity embedded in the transnational spread and transformation of educational ideas related to women’s education
On the parenthesisations of matrix chains : all are useful, few are essential
No full textThe product of a matrix chain consisting of n matrices can be computed in Cn-1 (Catalan’s number) different ways, each identified by a distinct parenthesisation of the chain. The best algorithm to select a parenthesisation that minimises the cost runs in O(nlogn) time. Approximate algorithms run in O(n) time and find solutions that are guaranteed to be within a certain factor from optimal; the best factor is currently 1.155. In this article, we first prove two results that characterise different parenthesisations, and then use those results to improve on the best known approximation algorithms. Specifically, we show that (a) each parenthesisation is optimal somewhere in the problem domain, and (b) exactly n+1 parenthesisations are essential in the sense that the removal of any one of them causes an unbounded penalty for an infinite number of problem instances. By focusing on essential parenthesisations, we improve on the best known approximation algorithm and show that the approximation factor is at most 1.143
Unravelling the dynamics of seed-stored mRNAs during seed priming
No full textSeed priming is a pre-sowing treatment that enables more efficient and uniform seed germination; however, it negatively affects seed longevity. In this work, the mRNA dynamics underlying a hydropriming treatment have been investigated. Polysome profiling was performed on seeds during different stages of hydropriming. Ribosome nascent chain complex sequencing (RNC-seq) elucidated transcriptomic and translatomic changes during the priming treatment. In contrast to mature dry seeds, hydroprimed seeds contain more mRNA-ribosome complexes, suggesting that the mRNAs that need to be translated during germination are already associated with ribosomes in the primed seeds, leading to a quicker restart of translation and thus faster germination upon re-imbibition. As a result of priming, seeds lose part of their stress-related transcriptome. This work highlights genes that might play a role in increasing the rate of germination after priming
A CRISPR homing screen finds a chloroquine resistance transporter-like protein of the Plasmodium oocyst essential for mosquito transmission of malaria
No full textGenetic screens with barcoded PlasmoGEM vectors have identified thousands of Plasmodium berghei gene functions in haploid blood stages, gametocytes and liver stages. However, the formation of diploid cells by fertilisation has hindered similar research on the parasites’ mosquito stages. In this study, we develop a scalable genetic system that uses barcoded gene targeting vectors equipped with a CRISPR-mediated homing mechanism to generate homozygous loss-of-function mutants after one parent introduces a modified allele into the zygote. To achieve this, we use vectors additionally expressing a target gene specific gRNA. When integrated into one of the parental alleles it directs Cas9 to the intact allele after fertilisation, leading to its disruption. This homing strategy is 90% effective at generating homozygous gene editing of a fluorescence-tagged reporter locus in the oocyst. A pilot screen identifies PBANKA_0916000 as a chloroquine resistance transporter-like protein (CRTL) essential for oocyst growth and sporogony, pointing to an unexpected importance for malaria transmission of the poorly understood digestive vacuole of the oocyst that contains hemozoin granules. Homing screens provide a method for the systematic discovery of malaria transmission genes whose first essential functions are after fertilisation in the bloodmeal, enabling their potential as targets for transmission-blocking interventions to be assessed
Miljöarkeologiska analyser av prover från en grop/grav inom L1970:6018, Forshälla socken, Uddevalla kommun, Bohuslän
No full textCase study on challenges in research with public partners : a personal data incident during recruitment for a survey study on ageing and housing
No full textOBJECTIVE: To highlight experiences from a personal data incident, which occurred during recruitment for a project focused on how housing choices and relocation are related to active and healthy ageing. RESULTS: Based on established collaboration, the researchers and representatives of housing companies planned for recruitment. Invitations to participate was distributed to persons registered with an interest in relocation. The invitation letter included information according to ethical requirements and a link to an online survey. Within a few days, the housing company was contacted by a person who had received the invitation stating that the company had not secured individual consent to the disclosure of personal data to the researchers. The company and the researchers initiated a range of immediate actions to manage the situation, including a plan for how to respond to persons who wanted their person data to be deleted, how to handle already collected data, and for the continued implementation of the recruitment process. We acknowledge that despite established collaboration based on long term commitment from all parties involved, ethical issues require constant attention. Whereas our case represents a hard-learned lesson on a sensitive ethical issue, the well-established collaboration was of paramount importance for how the situation was handled
Global history or European dominance? : A study of how teachers consider and encounter eurocentrism in teaching history at high school level education
No full textThis thesis investigates how high school history teachers in Sweden address and respond to Eurocentrism in their teaching. Based on qualitative semi-structured interviews with six history teachers, the study examines their strategies, challenges, and didactic approaches concerning Eurocentric content. Two theoretical frameworks guide the analysis: Lipsky’s street-level bureaucracy theory, which emphasizes teachers as policy-makers in practice, and John M. Hobson’s concept of subliminal Eurocentrism, which highlights implicit Western-centered narratives in education. The findings reveal a general awareness of Eurocentrism among the teachers, particularly within curriculum and teaching materials, but a varying degree of active critical engagement. Challenges include time constraints, limited knowledge of non-European history, and institutional norms. Nevertheless, the study shows that through reflective and intentional pedagogical choices, teachers can challenge dominant narratives and foster a more inclusive and global historical perspective. The thesis contributes to a deeper understanding of how Eurocentrism is managed in practice and provides insights for the development of history education that promotes global historical awareness and critical thinkin
Representing illiteracy : methodological challenges and ethical ramifications in research on illiterate refugees
No full textResearching vulnerable groups in social sciences is a balancing act of lifting their perspectives while protecting participants’ integrity from thoughtless methods. Newly arrived refugees with limited literacy face challenges in making their voices heard in both society and research. Yet, the methodological and ethical difficulties of meeting such challenges may also deter researchers from studying these groups, resulting in their exclusion from collective knowledge. The aim of this literature review is to explore methodological challenges of representing newly arrived refugees with limited literacy in social science research, and the ethical ramifications that come from them. Initially, we made a mapping review of language education research relating to refugee illiteracy. Secondly, we conducted a critical review of social science literature on the subject. Lastly, we analysed how various methods make these groups visible and accurately represented. Our findings show a significant gap in research involving both refugeehood and illiteracy. Moreover, we find that the limited supply of existing studies seldom account for methods and ethical practices to make the target group substantively represented. We also highlight studies with well thought out methodological and ethical practices, pointing towards a possible ethics of engagement
The rise of artificial intelligence for cognitive behavioral therapy : a bibliometric overview
No full textRecent years have seen a sharply rising interest in the scientific area dedicated to the study of the use of Artificial Intelligence (AI) for Cognitive Behavioral Therapy (CBT) research and applications (AI4CBT for brevity). Yet, little is known about how this interest is realized and hence the overall status, prospects, and possible challenges of AI4CBT as a field (e.g. breadth of the field, key topics and methods, key producing countries/institutions/authors, interdisciplinary grounding). This paper addresses this gap by developing a broad-spectrum bibliometric analysis towards acquiring a comprehensive overview of the AI4CBT field. Four key dimensions are analyzed (productivity, producers, productions, and contents) along the array of bibliographic metrics, including production trends over time, leading contributors at various levels, co-authorship, citation, and keywords co-occurrence networks, publication formats, key venues, methodological trends, and disciplinary assessment. The paper concludes by framing the status of AI4CBT as a scientific field, allowing to tie it to scientific and applicative challenges and opportunities that AI4CBT may encounter and offer as it further develops