Publikationer från Uppsala Universitet
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Quantification of Endogenous Steroids and Hormonal Contraceptives in Human Plasma via Surrogate Calibration and UHPLC-MS/MS
No full textQuantifying endogenous and exogenous steroids at low concentrations in biological matrices remains a major analytical challenge. Immunoassay-based diagnostics are limited by cross-reactivity, particularly at low levels, prompting a shift toward (ultra)high-performance liquid chromatography-tandem mass spectrometry ((U)HPLC-MS/MS) for clinical applications. A key limitation for endogenous hormone quantification is the absence of a true blank matrix for external calibration. To address this, we developed a surrogate calibration method employing 1,2-dimethylimidazole-5-sulfonyl chloride (DMIS) derivatization for estrogens, enabling sensitive and selective quantification alongside nonderivatized steroids. Stable isotope-labeled surrogate calibrants and internal standards were used to achieve matrix-matched quantification within a clinically relevant range. Parallelism between analytes and surrogate calibrants was systematically verified in plasma across multiple calibration levels. The method was further optimized through the use of narrow-bore UHPLC columns and refined chromatographic conditions to enhance sensitivity and resolution for a broad analyte panel. Combined with efficient protein precipitation and 96-well plate-based solid-phase extraction, the developed assay achieves pg/mL-level quantification in human plasma with high precision and accuracy. This integrated approach uniquely combines surrogate calibration for endogenous steroids with external calibration for exogenous contraceptives, including sensitive DMIS-based derivatization for estrogens, enabling comprehensive hormonal profiling in a single run. Beyond its analytical scope, the method outlines a structured validation strategy, which is aligned with regulatory principles, and may therefore serve as a practical reference for future LC-MS/MS assays employing surrogate calibration
Exceptional secular variation recorded in Neolithic hearths, Orkney and Swedish lake sediments
No full textGeomagnetic field models constrained by direct observations extend back some 400 years and the magnitude of decadal to centennial variations that they display is often assumed to be typical of the secular variation over longer timescales. Here we present archaeomagnetic directions from layered Neolithic hearths in Orkney, dating to around 3000 BCE, that challenge this assumption. Combining stratigraphic controls with radiocarbon dates allows for a precise chronology, which, in turn, implies directional change of more than 12 degrees/century lasting for 200 years, far in excess of anything seen at this latitude over the era of historical observations. These archaeomagnetic data are complemented by similarly rapid changes in inclination recorded in two high temporal resolution sediment cores from Ka<spacing diaeresis>lksjo<spacing diaeresis>n, Sweden. As well as raising the possibility of using archaeomagnetic dating within this important archaeological period, the new data pose questions regarding our understanding of the secular variation, the limitations of the historic field as a proxy for the past, and the underlying dynamical processes within the core. This research highlights the importance of archaeology to the wider scientific community and the potential of archaeological material to further our understanding of Earth processes
Searching for Paralytic Toxin, Tetrodotoxin, in Swedish Bivalve Shellfish
No full textTetrodotoxin (TTX), earlier known as a tropical paralytic neurotoxin from pufferfish poisoning, has increasingly been occurring in edible marine species, including filter-feeding bivalves, from relatively cold marine waters of some European countries. The defined conditions that promote the production of TTX, its origin or the processes of its accumulation in seafood are still not clarified. Recent studies in temperate waters show, however, that the accumulation of quantifiable levels of TTX in bivalves appears to be influenced by seawater temperature (>15 degrees C), which indicates a seasonal occurrence at these latitudes. Uncertainties still remain regarding how seawater temperature interacts with other climate and environmental factors or organisms in the marine ecosystem to result in detectable levels of TTX in shellfish. Knowledge of the occurrence and distribution of TTX in the marine environment where the edible bivalves grow is important for maintaining seafood safety, as the toxin is heat-stable and remains potent even after cooking. Therefore, in this study, 264 bivalve samples collected in 2019 and 2021 from 17 sites along the Swedish west coast were analyzed with LC-MS/MS to search for TTX. The study explores the hypothesis of TTX presence in Swedish marine waters, outlines the sample screening strategy and objectives, and reports no evidence of TTX presence in Swedish bivalve shellfish (>= 7.8 mu g/kg) based on the analyzed samples and the time periods in which the studied samples were collected
Fossils and DNA - Dating the Split Between Humans and Chimps
No full textThe relationship between chimps and humans is one of the most studied in the tree of life. As fossil evidence has shown our ape roots along with genetic sequencing proving the heritage we share with chimps, few question our shared ancestry. However while many stages of our evolutionary path from quadrupedal ape to man have been found, a youngest shared ancestor between us and the chimps has not been found. The last common ancestor. While direct evidence is lacking, attempts are made to identify when such a species would have existed; based on both genetic and fossil analysis. The molecular clock uses calculated mutation rates to count back to when this taxon would have existed, while morphological evidence in fossil discoveries are used to narrow down the span in which it could have existed as greatly as possible. By combining evidence from both these sources the hope was to identify a plausible timespan for when we split from the chimps, providing precise estimates at risk of losing accuracy with the shorter spans. By comparing results from multiple studies the age ranges 8 Ma to 7 Ma and 10 Ma to 9 Ma were established, based on different combinations of results. While incapable of setting a definitive age for our last common ancestor the results may indicate what new finds should be sought after to solve the mystery. Släktskapet mellan människan och schimpansen är en av de mest välstuderade evolutionära släktskapen i djurvärlden. Fossila fynd som uppvisat vår resa från mer aplika förfäder och genetisk analys som visar delat ursprung gör att få ifrågasätter detta släktskap. Trots alla fossila fynd av våra förfäder saknas en del i vårt delade ursprung, vår senast delade släkting. Direkt bevis av denna släkting saknas då inget material har hittats, men försök att datera när den kan ha levt görs med hjälp av både genetiskt material och fossil. Genom att använda en molekylär klocka går det att räkna tillbaka mutationer och datera när våra två grenar senast möttes, och morfologisk analys av fossil kan identifiera om en art uppkom innan eller efter denna splittring via distinkta drag. Genom att kombinera bevis från bägge hoppas detta verk etablera ett möjligt tidsspann för när splittringen skedde, med fokus på precision över säkerhet. Jämförelse av tidigare resultat och fynd resulterar i två mest troliga tidsspann på 8 Ma till 7 Ma och 10 Ma till 9 Ma, utifrån olika tolkningar av material. Dessa fynd ger ingen slutsats kring när våran senaste släkting levde men ger möjligen en insikt till var svaren bör sökas.
CEO with Power : On the Relationship between the Managing Director's Authority to Act and the Doctrine of Apparent Authority (Position-Based Authority).
No full textFrom dairy to plant products : Understanding their structural fingerprints with X-rays
No full textGlobal interest in milk alternatives increases rapidly due to health awareness, their allergen-friendliness, and concerns about sustainability. While dairy product microstructure and rheology are widely studied, plant-based alternatives remain less understood, with limited comparative studies of different plant sources and brands. This study uses ultra-small, small and wide-angle X-ray scattering (USAXS, SAXS, WAXS) to analyse structural fingerprints of commercial plant-based milk, yoghurt and cream alternatives versus dairy products. These techniques allow characterization across multiple length scales from large oil droplets and aggregated structures to carbohydrate/protein networks and glyceride crystalline phases. Correlations between intensity and fat (USAXS) and carbohydrate content (SAXS) provide structural insights, while SAXS and WAXS data correlated with solid fat and crystal packing are important for melting behaviour and viscosity perception. Light scattering confirmed fat-content-related size trends and revealed larger structures of non-lipid materials in plant-based samples. The study provides a basis for understanding scattering data where structural fingerprint plots, using colour scales to compare intensity and intensity gradient, allow ready data interpretation that will be beneficial for analysis with artificial intelligence (AI) tools. This approach helps optimize plant-based formulations by connecting structure and functionality and demonstrates the potential of scattering techniques in food structure research and design
The Truth and Nothing but the Truth Media Discourses on Body Data in Medical Age Assessments
No full textThis article analyses the discursive power of the datafied body, using the example of medical age assessments on unaccompanied minors in Sweden from 2017. Focusing on mainstream media discourses, it aims to raise critical attention to the truth-effect of body data, and the impact of media discourse on how it is transmitted to the broader public. This becomes particularly striking in relation to a case where such data were being miscalculated and misused, in a human rights scandal Sweden has yet to deal with. Ultimately, I argue that this machinery, while turning bodies into data, carries the logic of a lie detector of sorts, wiping out self-attesting truth, and undermining relationality and trust. Through the articulation and amplification of such logics, media discourse helped confirm and legitimise the power abuse of a nation state towards a particularly vulnerable group in search of protection. Hence, I maintain that the overreliance on body data in the current migration regime must be critically discussed in relation to ethical sensibilities and the growing dehumanisation of displaced populations
Image statistics substantiate Gaudí's naturalistic design principles
No full textHuman observers perceive natural and man-made environments differently, a distinction measurable through image statistics. However, limited evidence exists on how architectural style influences these statistics and, consequently, visual perception. Understanding this relationship is essential, as architectural design shapes both our visual and psychological experiences of built environments. The amplitude spectrum slope quantifies sharpness and detail in an image, with values closer to 1 typically found in photographs of natural scenes. Image entropy, reflecting unpredictability, also plays a role in visual attention-images with higher entropy are more likely to capture interest. In this study, we analyzed photographs of buildings designed by Antoni Gaudí, renowned for his nature-inspired architecture. Our findings reveal that Gaudí's buildings display an amplitude spectrum slope more similar to that of natural scenes than contemporary structures from the same area, alongside higher image entropy. Effect size measures indicated that the observed differences in slope constant and entropy between images of Gaudí buildings and contemporary buildings were medium and large in magnitude. The presence of trees in front of contemporary buildings shifts their image statistics toward naturalistic values. These results suggest that incorporating naturalistic design elements into architecture can alter image statistics, potentially influencing perception and aesthetic experience. In contemporary architecture, where minimalist and geometric styles are prevalent, these insights highlight the potential benefits of reintroducing complexity and naturalistic aesthetics to create more engaging and psychologically restorative built environments.These authors jointly supervised this work: Karin Nordström and Christian Benedict.</p
Incitament som ger resultat : En studie om utformningen av incitamentsprogram
No full textDenna kvalitativa fallstudie undersöker hur ett svenskt konsultföretag, specialiserat på incitamentslösningar, utformar sina incitamentsprogram samt vilka faktorer som upplevs som mest effektiva vid denna utformning. Incitamentsprogram fungerar som ett verktyg för organisationer för att belöna prestation och motivera sina anställda. Dessa program spelar en allt viktigare roll inom företagsstyrning och denna studie undersöker hur sådana program kan utformas för att effektivt styra beteende, öka motivation samt förbättra måluppfyllelse. Empirin bygger på ett antal intervjuer med anställda på fallföretaget. Resultaten visar att programmen fungerar bäst när de är anpassade till individens roll, bygger på mätbara mål och är tydligt kommunicerade till deltagarna. Motivation skapas inte enbart genom ekonomiska belöningar utan även genom att tillgodose autonomi, kompetens och samhörighet. Vidare finns det ingen universell modell för att utforma ett effektivt incitamentsprogram. Varje program måste anpassas efter mottagarens behov, med hänsyn till organisationens förutsättningar och med en förståelse för människans grundläggande beteende
It’s All Greek to Them : Challenges in Translating Greek Slang and Idioms viaLLMs and NMT
No full textThis thesis investigates the relatively understudied task of translating Greek(medium-resource language) slang and idiomatic expressions. While MachineTranslation (MT) has made significant advancements over the past decade —firstthrough Neural Machine Translation (NMT) and later with Large Language Mod-els (LLMs)—, its effectiveness remains underexplored for informal and culturallyspecific linguistic constructions, especially in under-resourced settings. Thiswork addresses these challenges by creating two novel parallel Greek-Englishdatasets: one for slang and one for idioms, and testing three LLMs (Gemma, Llama, Mistral) and one NMT model (Helsinki). To probe the models’ knowledge,both datasets are also manually annotated with "informativeness" scores with theassistance of human participants, with them indicating how easily the meaningof a target expression can be inferred in a given context. An error analysis is alsoconducted to identify specific model weaknesses. Results show consistently poortranslation performance across all models, for both datasets, with no statisticallysignificant differences among them. However, localized differences in handlinginformativeness and substantial variation in error types are observed. Thesefindings align with existing research highlighting the challenges of translatingunder-resourced languages and culturally embedded expressions