Publikationer från Uppsala Universitet
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Optimizing Satellite Mission Design: an Algorithmic Approach : Modelling Satellite Swarms for Earth Observation in Very Low Earth Orbit
No full textThe first ever launch of a satellite, Sputnik 1, took place in 1957. Since then, great advancements in satellite technology have been made. With over 12 000 satellites currently in orbit and projections exceeding 100 000 by 2030, the satellite industry is expanding now more than ever. To keep up with this growth, the satellite design process must change. Historically marked by long development cycles, extensive safety margins, and conservative engineering, one must now be able to quickly go from a design phase to a construction and testing phase. In this thesis, a model is presented that links Earth Observation mission requirements directly to satellite-level and swarm-level design parameters. The model maps 18 user-defined inputs to 18 outputs, encompassing satellite subsystems such as power, propulsion, communications, and payload. In addition, swarm specifications such as inter-satellite distances and swarm sizes are determined. The model was validated by inputting specifications from existing satellite missions and comparing the output with actual satellite parameters. It was found that the model predicts imaging performance with high accuracy, and provides reliable estimates of solar panel sizing. It performed less accurately when computing other attributes such as propellant mass and battery size. This inaccuracy can likely be attributed to different design philosophies rather than fundamental model flaws. Unfortunately, the validation method suffered from a lack of publicly available data, leading to parts of the model being unverifiable. Nevertheless, the proposed model can serve as a valuable tool for rapidly estimating important satellite subsystem dimensions, providing a foundation upon which engineers can build
A tiny Indo-European 'cow-suckler'? : A new etymology for Breton buzhugenn, Middle Cornish vethygan and Gascon bousic, boudic 'earthworm'
No full textThis chapter argues for the existence of a Celtic reflex of Proto-Indo-European *gʷou̯-dʰVh₁- ‘cow-suckler; chthonic creature’, a reconstruction otherwise posited on the basis of Vedic godhā́- ‘monitor lizard’, Latin būfō ‘toad’ or ‘some kind of rodent’ and Armenian kovadiacc ‘lizard’. Celtic is argued to have formed a diminutive derivative *bou̯d-īko- (< “*gʷou̯-dʰh₁-iko-”), originally ‘little cow-suckler’, with reflexes in Breton buzhugenn, Middle Cornish vethygan and Gaulish *bou̯dīko- (→ Gallo-Romance *bọˈðikọ-, reflected in Gascon bousic, boudic and Saintongeais bouic), all with the meaning ‘(earth)worm’. The Celtic derivative *bou̯dīko- is closely paralleled both formally and semantically by Dardic and Nuristani reflexes of Indo-Iranian *gau̯dʰā̆H- and its diminutive *gau̯dʰ(H)ikaH (< *gʷou̯-dʰh₁-ikeh₂), also with the meaning ‘worm’.Languages and Myths of Prehistory (LAMP
Characterizing the Sulfated and Glucuronidated (Poly)phenol Metabolome for Dietary Biomarker Discovery
No full text(Poly)phenols, bioactive compounds abundant in plant-based diets, have attracted interest for their potential role in preventing chronic diseases including cardiometabolic and neurodegenerative diseases. This study investigates the global sulfatome and glucuronidated metabolome in urine samples from 100 healthy adults collected pre- and postintervention following a 3-day (poly)phenol-rich intervention consisting of flaxseeds, raspberry powder, and soy milk. Using untargeted mass spectrometric metabolomics combined with selective phase II enzymatic treatment, we detected 156 sulfated and 143 glucuronidated metabolites in urine samples. Significant changes postintervention were observed for 91 sulfates and 94 glucuronides. Receiver operating characteristic curve analysis identified a combination of six polyphenol-derived key metabolites: glucuronidated daidzein and the sulfated compounds of pyrogallol, ferulic acid, 4-methoxyphenol, enterolactone, and resorcinol, which resulted in the best combination with the highest predictive AUC of 0.97. These findings underscore the utility of these metabolites as sensitive and selective biomarkers of (poly)phenol dietary intake
Quartz cores and their flakes distribution in Eastern Middle Sweden : A regional exploratory study of worked quartz distribution in Eastern Middle Sweden with a focus on the Stone Age
No full textEastern Middle Sweden is an area that for a long period has been underrepresented in archaeology compared to southern Sweden. Quartz, the lithic material that is native to the area, is also difficult to date and has long been poorly understood in relation to flint, which occurs in southern Sweden. How processed quartz distribution relates to the place of its extraction as well as differences in how the material is processed depending on weight, reduction method, physical geography and distinctions in time and space have been investigated in the study. The study was an exploratory data analysis that used GIS to examine 23,246 individual finds from 418 sites dated from 12,000 BCE to 1700 BCE by SHM. It has been established that processed quartz distribution in eastern Middle Sweden has been strongly affected chorologically as a result of if the material was found in connection with a site in what was then an archipelago or hinterland. Chronologically, differences in the distribution of the source material have been noted mainly based on whether the material was processed before or after 4500 BCE.Östra Mellansverige är ett område som under lång period varit underrepresenterat inom arkeologin jämfört med södra Sverige. Kvarts, det litiska materialet som är ursprungligt till området, är dessutom svårdaterat och har länge varit dåligt förstått relativt till flinta som förekommer i södra Sverige. Hur bearbetad kvarts distribution relaterar till platsen för dess extraktion samt skillnader i hur materialet bearbetats beroende på vikt, reduktionsmetod, naturgeografi och distinktioner i tid och rum har undersökts i studien. Studien var en explorativ dataanalys som använde GIS för att undersöka 23 246 individuella fynd från 418 fornlämningar daterade från 12 000 f.v.t. till 1700 f.v.t. av SHM. Det har kunnat konstateras att bearbetad kvarts distribution i östra Mellansverige starkt påverkats korologiskt som ett resultat om materialet hittats i anslutning till en fornlämning i vad som var det dåtida skärgårdsområdet eller inlandet. Kronologiskt har skillnader i distributionen av källmaterialet noterats främst baserat på om materialet bearbetats innan eller efter 4500 f.v.t.
A diverse landscape of FGFR alterations and co-mutations suggests potential therapeutic strategies in pediatric low-grade gliomas
No full textOncogenic alterations in fibroblast growth factor receptor (FGFR)-family proteins occur across cancers, including pediatric gliomas. Our genomic analysis of 11,635 gliomas across ages finds that 5.3% of all gliomas harbor FGFR alterations, with an incidence of almost 9% in pediatric gliomas. Alterations in FGFR proteins are differentially enriched by age, tumor grade, and histology, with FGFR1 alterations associated with glioneuronal histologies. Leveraging isogenic systems, we confirm FGFR1 alterations to induce downstream Mitogen Activated Protein Kinase (MAPK) and mTOR signaling pathways, drive gliomagenesis, activate neuronal transcriptional programs and exhibit sensitivity to MAPK pathway and pan-FGFR inhibitors. Finally, we perform a retrospective analysis of clinical responses in children diagnosed with FGFR-altered gliomas and find that treatment with currently available inhibitors is largely associated with stability of disease. This study provides key insights into the biology of FGFR1-altered gliomas, therapeutic strategies to target them and associated challenges that still need to be overcome.De två första författarna delar förstaförfattarskapet</p
When things fall apart : Understanding radiation damage to radiosensitisers
No full text The effectiveness of radiotherapy relies on microscopic processes where atomic bonds are broken or formed in response to X-ray radiation. To understand and improve the therapeutic outcomes, it is essential to study these interactions on a molecular level, particularly for radiosensitising agents in that could enhance DNA damage in cancer cells. This work investigates the fragmentation dynamics of halogenated molecules in gas phase after deep core ionisation by X-rays and positive charge accumulation. We used synchrotron experiments with mass spectrometry and Born-Oppenheimer based molecular dynamics simulations to study how molecules respond after being ionised at different photoabsorption edges. Nitroimidazole-based molecules doped with halogen atoms show similar production of fragments during ionisation of low-Z elements. A consistent high ion yield of reactive species such as NO2+ and NO+ is observed, known to contribute to cellular damage. Ionisation of the halogen atoms produce energetic single-atom fragments, as measured in coincidence with photoelectrons. Production of this fragments depend on the final charge state of the molecule. Our simulations indicate that these fragments travel only short distances in water, promoting highly localised damage near the ionisation site. Introducing a water molecule into a radiosensitising system alters fragmentation in a subtle way. Water molecules enhance the release of halogen ions however, full atomisation of the molecule is the most dominant process. These findings help bridge the gap between isolated molecular studies and biological conditions. Incorporating iodine-doped deoxyuridine (IUdR) into DNA reveal strong enhancements in fragmentation of the DNA-backbone at ionisation energies of deep core levels in the iodine atom. Our simulations showed that small reactive fragments, particularly those classified as reactive oxygen species (ROS), are formed. Fragmentation patterns change depending on the oligonucleotide chain length. Bond scission was observed several bases away from the iodine site, suggesting that core holes and resulting radiation damage migrate along the backbone of the oligonucleotide. To model core hole localisation following X-ray ionisation, new simulation tools based on Born-Oppenheimer molecular dynamics have been developed. This enables a more accurate prediction of non-symmetric fragmentation and charge localisation in small molecules. These insights advance our understanding of molecular-level radiosensitisation and its relevance to radiotherapy
Träffsäkerheten hos riktkurser: En studie om svenska och utländska analytikers förutsägelseförmåga
No full textThis study examines the accuracy of target prices issued by Swedish and foreign analysts for companies listed on Nasdaq Stockholm. The aim is to assess how well these target prices predict future stock prices and whether there are significant differences in forecast accuracy between these two groups. Additionally, the study investigates whether company characteristics such as market capitalization, return on assets, and earnings before interest, taxes, depreciation and amortization influence forecast precision. A quantitative approach with a deductive method was adopted, using secondary data from 2021 to 2024. Descriptive statistics, t-tests, correlations, and multiple regressions were conducted to analyze the accuracy of the target prices. The results show that target prices, on average, deviate approximately 35% from actual stock prices on year after the target price was published. No significant difference in accuracy was found between Swedish and foreign analysts. Only the future stock price exhibited a significant relationship with the forecast error (MAPE), while the other explanatory variables were statistically insignificant. Furthermore, evidence of systematic optimism was found in the target price forecasts. The study concludes that analysts´ target prices should be interpreted with caution, as they tend to overestimate future prices and exhibit predictive accuracy regardless of the two groups
Long-term follow-up of MRD-guided ibrutinib plus venetoclax in relapsed CLL : phase 2 VISION/HO141 trial
No full textPatients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL) are treated with fixed-duration B-cell lymphoma 2 inhibitors + CD20 monoclonal antibodies or continuous Bruton tyrosine kinase (BTK) inhibitors. Although continuous treatment may lead to cumulative toxicity or resistance, fixed-duration treatment may lead to undertreatment and early relapse. Efficacy and safety of minimal residual disease (MRD)-guided treatment cessation of ibrutinib + venetoclax (I+V) with reinitiated I+V upon MRD conversion was evaluated in the randomized VISION/HO41 phase 2 study. Four-year follow-up including long-term toxicity and MRD kinetics are reported. Patients received ibrutinib for 2 (28-day) cycles followed by 13 cycles of I+V. Patients reaching undetectable MRD at 4 years (<10−4, flow cytometry) in the blood and bone marrow at cycle 15 (C15) were randomized 2:1 between treatment cessation with reinitiated I+V upon detectable MRD2 (dMRD2; sensitivity of ≥10−2 by flow cytometry) and ibrutinib maintenance. MRD4-positive patients at C15 remained on ibrutinib (dMRD4 arm, defined by MRD sensitivity of ≥10−4 by flow cytometry). With a median of 51.7 months, the estimated 4-year overall survival (OS) was 88%, progression free survival (PFS) was 81%; 14% of patients required next-line treatment (NT). For patients randomized to treatment cessation, 40% had reinitiated therapy per protocol because of dMRD2. No difference between treatment cessation, ibrutinib maintenance, or the dMRD4 arm continuing ibrutinib was seen for OS, PFS, or NT in landmark analysis from C15 time of randomization. Lower toxicity was demonstrated for the treatment-cessation arm. MRD-guided cessation and reinitiation of I+V for R/R CLL is feasible, reduces toxicity compared with indefinite BTK inhibitor, while providing comparable PFS rates. This trial was registered at www.clinicaltrials.gov as #NCT03226301
Return governance and diplomacy between Türkiye and Afghanistan
No full textThere is growing scholarly and policy interest in understanding how destination and transit countries develop return migration policies and collaborate with origin countries. This study investigates the dynamics, drivers and outcomes of the collaborative process between Turkish and Afghan authorities in governing the return of Afghan migrants. Drawing on the concept of return diplomacy, derived from the broader framework of migration diplomacy-which explores the interplay between cross-border mobility and foreign policymaking-we analyse the bilateral talks and arrangements shaping these returns. Our examination of official documents, news sources, interviews and engagements with key informants reveals that authorities on both sides get involved in return diplomacy by leveraging historical and religious networks, as well as humanitarian diplomacy instruments. The drivers of this process are rooted in the domestic priorities of the Turkish government to manage return flows and the expectations of Afghan authorities and the Taliban for international legitimacy and aid through cooperation. The collaboration reflects a blend of formal and informal relations and practices. The outcomes, however, highlight significant opacity in bilateral negotiations and arrangements. These efforts lack a structured readmission framework and have resulted in record-high coerced returns of Afghan migrants (officially 42,498 in 2022) with minimal monitoring. While not fully representative, this case study provides valuable insights for enhancing theories of migration diplomacy and return governance by underscoring the utility of a decentred approach and emphasis on South-to-South contexts