Publikationer från Uppsala Universitet
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Emergence of pseudoresonance in high-intensity resonant inelastic x-ray scattering
No full textWe report resonant inelastic x-ray scattering (RIXS) spectra of neon atoms interacting with intense x-ray pulses generated using an x-ray free-electron laser (XFEL). We find that an unexpected peak emerges near the K alpha line of Ne, which does not coincide with any physical resonances of neon ions. We perform theoretical calculations based on a quantum-state-resolved rate-equation approach with x-ray-induced processes including possible resonant excitations. Our dynamics simulations demonstrate that a sequence of multiple resonant photoabsorption events are involved and the interplay of those multiple resonances in combination with the relatively large spectral bandwidth of XFEL radiation leads to the emergent resonance-like structure at a position where no resonances exist. Our finding offers critical guidance for future applications of high-intensity RIXS at XFEL facilities
The pure spinor superparticle and 10D super-Yang-Mills amplitudes
No full textWe present a prescription for computing tree-level scattering amplitudes in 10D super-Yang-Mills (SYM) theory using the pure spinor worldline formalism. The pure spinor formalism has proven to be a powerful framework for studying supersymmetric field theories, providing manifestly covariant and BRST-invariant formulations of amplitudes. By incorporating the worldline approach, we construct a first-quantized representation of SYM amplitudes in 10D, where interactions are encoded through the insertion of vertex operators along the particle's trajectory. We explicitly compute the N-point function, demonstrating an agreement with the alpha '-> 0 limit of open superstring amplitudes and confirming that the kinematic numerators satisfy the expected BRST relations. Our results establish the pure spinor worldline formalism as a tool for studying scattering amplitudes and suggest further applications to 11D supergravity
Pharmacometric efficacy and safety evaluations within the fields of pulmonary tuberculosis and COVID-19
No full textTuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. Each year, more than 10 million people are estimated to develop TB, and over 1.2 million die from the disease, and resistance to drugs is a major challenge. Another infectious disease, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulted in over 700 million infections and nearly 7 million deaths worldwide over several years. The aim of this thesis was to use pharmacometric methods to evaluate the efficacy and safety of drugs for tuberculosis and the efficacy of a repurposed vaccine for COVID-19. To improve TB drug development, a standardized pharmacometric model-based early bactericidal activity (EBA) analysis workflow was established to analyze EBA trials, and sample size calculations were performed to inform future EBA trial designs. Application of this workflow to a conducted EBA trial revealed that adding rifampicin to meropenem (administered with amoxicillin and clavulanic acid) did not enhance short-term activity in patients with rifampicin-resistant TB. Furthermore, pharmacometric modelling and simulation were used to optimize MDR-TB treatment with linezolid. A model-informed precision dosing algorithm was developed, enabling individualized dosing from the first day of treatment, enabling both efficacious and safe treatment. Safety targets for linezolid-related adverse events, such as anemia, thrombocytopenia, and peripheral neuropathy were also established, providing more information on the adverse events linked to linezolid. Finally, a reproducible pharmacometric workflow was implemented to facilitate data processing, reporting, and analysis of a phase 3 trial assessing whether the repurposed Bacillus Calmette-Guérin TB vaccine could reduce morbidity and mortality from COVID-19 and respiratory tract infections (RTIs). Pharmacometric analysis of this trial allowed for the identification of the risk factors for COVID-19 and RTIs in frontline healthcare workers. In summary, this thesis used pharmacometric methods to optimize the EBA evaluations in TB with a standardized EBA workflow and to develop an algorithm for individualized precision dosing of linezolid in patients with MDR-TB. Furthermore, pharmacometric modelling enabled efficacy evaluation of a repurposed TB vaccine against COVID-19 and confirmation of risk factors for RTIs and COVID-19 in frontline healthcare workers
Elever löser öppna problem i matematik. : En kvantitativ studie om förekomst och kombinationer av heuristiker i elevers skriftliga lösningar till öppna problem i matematik.
No full textDenna studie behandlar elevers olika problemlösningsstrategier vid lösning av ett öppet matematiskt problem. Studien är ett SJAS-arbete (Självständigt arbete i skola och förskola), vilket innebär att något som identifierats under den verksamhetsförlagda delen av utbildningen undersöks i samarbete med en partnerskola till Uppsala universitet (Uppsala universitet, 2025). Syftet med studien var att undersöka vilka heuristiker som elever i årskurs två använder sig av i skriftliga lösningar av ett öppet matematiskt problem. För att uppnå studiens syfte samlades 46 skriftliga elevlösningar in som sedan analyserades med hjälp av en kvantitativ innehållsanalys. Studien har sin teoretiska grund i kognitivismen med ett särskilt fokus på begreppet heuristiker, som är tumregler eller lösningsstrategier som används vid problemlösning. Den första forskningsfrågan som besvarades var; ”I vilken utsträckning förekommer olika heuristiker i det insamlade materialet?” med tillhörande underfråga ”Vilken heuristik är mest respektive minst förekommande?”. Den andra forskningsfrågan som besvarades var; ”Vilka kombinationer av heuristiker förekommer i det insamlade materialet?” med tillhörande underfråga ”Vilken heuristik är vanligast i kombinationerna som uppvisar minst en korrekt lösning?”. De viktigaste resultaten är att samtliga elevlösningar innehöll någon eller några av tidigare identifierade heuristiker och att de förekom i varierande utsträckning. Heuristiken gissa och pröva förekom i störst utsträckning medan arbeta baklänges var minst förekommande. Ett annat viktigt resultat är att många olika samt unika kombinationer av heuristiker kunde identifieras. Den heuristik som var vanligast i kombinationer som uppvisade minst ett korrekt svar var gissa och pröva. Huvudsakligen bekräftar studiens resultat den tidigare forskningen, som bland annat visar att öppna problemlösningsuppgifter möjliggör användningen av flera olika lösningsstrategier. Samtidigt modifierar resultatet tidigare forskning gällande användandet av enskilda heuristiker som lösningsmetod. Studiens viktigaste slutsatser är att elever redan i årskurs två använder sig av olika heuristiker vid lösning av öppna problem, att eleverna i studien använde sig av många olika unika kombinationer samt att heuristiken gissa och pröva användes frekvent.
Uses of Shoah History and Representations of the Jews in the Greek Left-Wing Press after 1974 : From the Broadcast of “Holocaust” (1979) to the Lebanon War (1982)
No full textThis thesis investigates how Holocaust history was represented in the political and cultural discourse of the Greek Left after the 1974 restoration of democracy. Focusing on two key case studies—the reception of the television series Holocaust (1979) and the coverage of Israel‘s invasion of Lebanon (1982) across six left-wing publications—it examines how the Shoah was appropriated as a moral and political resource and how this process intersected with the rearticulation of antisemitism in post-junta Greece. The study argues that the evolution of Holocaust consciousness and the transformation of antisemitism were deeply intertwined during Metapolitefsi. Drawing on Karlsson‘s typology of the uses of history, Rothberg‘s multidirectional memory, and debates on "new antisemitism," it reveals how antifascist and anti-imperialist narratives shaped Holocaust memory. It shows that Holocaust imagery was instrumentalized to express political outrage, often detached from its Jewish context, and that anti-Zionist discourse frequently reproduced antisemitic patterns through the conflation of Israel with "the Jews." By tracing the different uses of Holocaust history, this thesis reveals the entanglement of memory with ideology in the Greek Left‘s discourse and highlights the broader challenges of integrating the Jewish experience into the historical consciousness of modern Greece.
Measurement of jet track functions in pp collisions at â\u88\u9as=13 TeV with the ATLAS detector
No full textMeasurements of jet substructure are key to probing the energy frontier at colliders, and many of them use track-based observables which take advantage of the angular precision of tracking detectors. Theoretical calculations of track-based observables require 'track functions', which characterize the transverse momentum fraction r(q) carried by charged hadrons from a fragmenting quark or gluon. This letter presents a direct measurement of r(q) distributions in dijet events from the 140 fb(-1) of proton-proton collisions at root s = 13 TeV recorded with the ATLAS detector. The data are corrected for detector effects using machine-learning methods. The scale evolution of the moments of the r(q) distribution is sensitive to non-linear renormalization group evolution equations of QCD, and is compared with analytic predictions. When incorporated into future theoretical calculations, these results will enable a precision program of theory-data comparison for track-based jet substructure observables.For complete list of authors see http://dx.doi.org/10.1016/j.physletb.2025.139680</p
The impact of camouflaging autistic traits on psychological and physiological stress : a co-twin control study.
No full textBackgroundCamouflaging autistic traits is suggested to increase stress and the risk of autistic burnout. However, the relationship with psychological and biological markers of stress and the influence of familial factors on this relationship remain unclear. MethodsIn a neurodiverse twin sample (N = 315; 69 diagnosed with autism), we examined associations between camouflaging behaviors (operationalized as the discrepancy between the Autism Diagnostic Observation Schedule 2nd edition [ADOS-2] and the Autism Quotient [AQ]), rated stress-related symptoms, and biological long-term stress measured via hair cortisol concentration (HCC). Associations were analyzed across the full sample, accounting for age, sex, and HCC confounders, as well as within-twin pairs, implicitly adjusting for genetic and environmental confounding. ResultsAcross individuals, camouflaging was associated with increased HCC, particularly in autistic and adult subsamples, while associations with stress-related symptoms were only evident in adults. Within-pair analyses revealed no associations in the full sample, suggesting familial confounding. Interestingly, in adjusted within-pair models in autistic and adult twin-pairs, camouflaging was linked to lower HCC. LimitationsOnly the adult participants provided self-reports of autistic traits (AQ) and stress-related symptoms, while parent-reports were used for the younger participants. This difference in reporting sources may have reduced the accuracy of data for the younger subgroups in our sample. ConclusionsThe findings indicate that camouflaging is associated with increased biological long-term stress at the population level but that familial factors may influence this relationship. Future research is needed to explore these complex dynamics and their implications for mental health and adaptive functioning in autistic individuals
Estradiol and non-REM sleep attenuate physiological and emotional responses to social-evaluative stress in healthy women.
No full textBACKGROUND: This study examined whether individual differences in estradiol and sleep predict autonomic and cognitive responses to social-evaluative stress in healthy young women. METHODS: Forty-two healthy women underwent overnight in-laboratory sleep monitoring, followed by a social-evaluative stress task the next morning, which involved listening to a playback of their own karaoke singing. Pre-task estradiol levels were measured via blood sampling. Autonomic responses were assessed using pupil dilation during the playback, while cognitive responses were indexed by subjective stress ratings collected immediately afterward. RESULTS: Higher estradiol concentrations (range: 40-1129 pmol/L) were associated with reduced peak pupil dilation (range: 0.21-1.70 mm above the 95% confidence interval upper bound of baseline) and cumulative pupil dilation (total pupil expansion exceeding the individual baseline over 45 s; range: 64-3139 mm, p < 0.001), indicating lower autonomic arousal. In contrast, estradiol was not associated with subjective stress ratings (range: 10-98 mm on a 100-mm scale). Greater N3 sleep duration (range: 27-172 min), but not N1 or N2, was associated with lower subjective stress (p = 0.032), whereas REM sleep duration (range: 53-152 min) showed no association with either outcome. None of the sleep measures was significantly related to pupillometry outcomes, and no interaction effects were observed between estradiol and sleep measures. CONCLUSIONS: Estradiol and N3 sleep appear to independently modulate distinct facets of the response to social-evaluative stress: higher estradiol levels were associated with reduced autonomic arousal, while greater N3 sleep duration was linked to lower subjective stress. By revealing parallel pathways through which estradiol and sleep shape physiological and cognitive reactions to stress, this work contributes to a more nuanced understanding of the biological factors that may influence mental health and stress resilience
Heteroresistance in Bacteria –Prevalence, and Mechanisms
No full textAntibiotic heteroresistance (HR) is a phenotype characterized by small subpopulations of cells with elevated resistance present in a main susceptible bacterial population. HR often evades detection by routine antimicrobial susceptibility testing, potentially leading to treatment failure, and occurs across multiple bacterial species and antibiotic classes. Known mechanisms include (i) genetic alterations such as point mutations, insertions, and deletions, and (ii) increased resistance gene copy numbers through tandem gene amplifications, increased plasmid copy number and transposition of antibiotic resistance genes into high copy number plasmids or highly expressed loci. This thesis investigates HR prevalence in Gram-positive bacteria and the genetic mechanisms causing HR. In Paper I, HR prevalence and mechanisms were studied in 40 clinical Staphylococcus aureus isolates from four European countries against six clinically relevant antibiotics. HR isolates were frequent against gentamicin (69.2%), oxacillin (27%), daptomycin (25.6%), and teicoplanin (15.4%), and absent for linezolid and vancomycin. Genomic analyses revealed that HR primarily arise from chromosomal mutations affecting various cellular pathways, contrasting with the dominant mechanisms of increased gene copies in Gram-negative bacteria. In Paper II, 40 clinical Enterococcus faecalis isolates from the same four European countries as in paper I were analyzed and HR was observed for daptomycin (20%), gentamicin (13.2%), and tigecycline (35.9%), but absent for linezolid and vancomycin. Several different genetic mechanisms, including chromosomal mutations, deletions in regulatory region of an antibiotic resistance gene leading to overexpression, and transposon-mediated increased gene copy number were identified in HR isolates, highlighting parallels to HR in S. aureus. In Paper III, we assessed the role of 19 recombination-associated genes in tandem amplification-driven HR in Escherichia coli. A clinical plasmid conferring tobramycin HR via tandem amplification of aac(3)-IId was introduced into 19 recombination-gene knockout strains. All constructed isolates exhibited HR, but deletions in recA and recB substantially reduced tandem amplifications, shifting the mechanism of the HR isolates towards increased plasmid copy number or mutations. Partial reductions in HR were observed in recC, recJ, ruvA, and ruvC mutants, while other deletions had minimal impact. In conclusion, this thesis demonstrates the high prevalence of HR and advances the understanding of the genetic mechanisms of HR in Gram-positive and Gram-negative pathogens. The results underscore the need for improved HR detection methods and reveal the multitude of mechanisms that can generate HR, highlighting challenges in targeting HR-mediated antibiotic resistance