Publikationer från Uppsala Universitet
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Collective decision-making under predator threat is faster in guppy shoals selected for larger telencephalon size
No full textAvoiding predation is essential for most animals. For group-living species, effective predator avoidance relies on making fast and accurate collective decisions. However, the mechanisms underlying the ability to make adaptive collective decisions and to coordinate movements under predation threat remains unclear. Here, we used guppies artificially selected for divergence in the size of the telencephalon, the main brain region for advanced decision-making in vertebrates, to test the influence of telencephalon size on collective decision-making under predation threat. We measured the latency and accuracy of collective decision-making to avoid a model predator in guppy shoals. In addition, we used high-resolution tracking analysis to assess shoaling dynamics under predator threat between the telencephalon size selection lines. We found that collective decision-making latency was shorter in large telencephalon guppy shoals, indicating that variation in telencephalon size can cause variation in the ability to avoid predation. This result is unlikely to be driven by differences in boldness, as several standard tests suggest that there is no difference in boldness between the telencephalon size selection lines. General aspects of shoaling dynamics did not differ between the telencephalon size selected lines. Our study highlights that rapid mosaic changes in brain region size may be an important mechanism behind social behavioural variation with strong fitness implications
Supersymmetric scale-separated AdS3 orientifold vacua of type IIB
No full textI construct supersymmetric AdS3 vacua of type IIB string theory that exhibit parametric scale separation in the controlled regime. These solutions arise from compactifications on seven-dimensional manifolds equipped with co-closed G2-structures, in the presence of orientifold planes preserving minimal supersymmetry. I focus on orbifolds of a specific solvmanifold and all seven-dimensional nilmanifolds, each requiring distinct configurations of intersecting O5-planes, which are treated in the smeared approximation. Weak string coupling and large volumes can be achieved for classical backgrounds on both nilmanifolds and solvmanifolds by tuning unbounded fluxes to large values. This achieves scale separation in the nilmanifold case, but the same cannot be concluded for the solvmanifolds. Furthermore, for some solutions, the holographic field theory operators dual to the lightest scalar fields have integer conformal dimensions at tree level, as in other scale-separated type IIA orientifold backgrounds
Enduring prenatal androgen effects on the female brain
No full textStructural sex differences in the brain have been reported as early as infancy. Prenatal androgens have been hypothesized to contribute to these sex differences but the available evidence is inconclusive. Congenital adrenal hyperplasia (CAH) is a genetic variant that causes high levels of androgens during gestation in females and more male-typical behaviour after birth, whereas androgen levels and behaviour in males with CAH are largely typical. To assess whether prenatal androgens affect brain anatomy, we studied the largest CAH sample to date, matched pair-wise to a control group for sex, age, education and verbal intelligence. Anatomical sex differences were quantified using T1-weighted brain scans and a relevance-vector machine, which generated a continuous probabilistic brain sex index. Females with CAH exhibited significantly more male-like brain characteristics than control females, whereas no differences were observed between males with CAH and control males. This observed shift towards a male-typical brain anatomy in females with CAH supports the hypothesis that prenatal androgen exposure has formative effects on the human brain that persist into adulthood. Using a continuous probabilistic brain sex index, Kurth et al. observed that women with congenital adrenal hyperplasia, but not men with congenital adrenal hyperplasia, exhibited more male-like brain characteristics than sex-matched controls. This suggests that prenatal androgens shape the human brain, with effects persisting into adulthood
Situated Artificial Intelligence for Brand Identity Creation: Grounding Generative Content in Digital Branding
No full textThis thesis explores how organizations employ generative artificial intelligence (GenAI) in the creation of brand identity within digital advertising contexts, with a particular focus on the concept of grounding as part of the Situated AI framework. Grounding refers to the alignment of AI generated outputs with the authentic values, vision, and cultural context of a brand. While GenAI offers unprecedented capabilities for producing creative and scalable content, the quality and strategic value of such outputs depend heavily on the extent to which they are anchored in brand-specific knowledge and organizational objectives. A qualitative research design was adopted, drawing on semi-structured interviews with selected creative agencies. These agencies varied in their adoption of GenAI, from experimental integration in early creative stages to more structured and brand aligned uses. The interviews examined how practitioners design, refine, and re-prompt AI systems to achieve grounded outcomes, and how organizational processes, brand guidelines, and human oversight influence the role of GenAI in branding. Findings indicate that effective grounding requires a combination of technical prompt engineering skills, iterative design processes, and deep familiarity with brand identity. Agencies that embedded GenAI within collaborative workflows and maintained continuous human input were more likely to produce outputs that reinforced brand authenticity and strategic positioning, whereas superficial or unstructured use of GenAI often led to outputs that lacked contextual fit or emotional resonance. The study contributes to both theory and practice by demonstrating how grounding operates as a critical mechanism for aligning GenAI outputs with brand identity, extending the Situated AI framework into the domain of creative brand work. It also offers practical insights for organizations seeking to integrate GenAI in ways that enhance creativity without compromising brand coherence
Anastomosis versus rectal stump procedure in cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for colorectal and appendiceal peritoneal metastases : A comparative study
No full textAim Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is the standard treatment for peritoneal metastases (PM) of colorectal or appendiceal origin. Rectal anastomotic leakage (RAL) or rectal stump blow-out is a serious complication following rectal resection after CRS-HIPEC. This study aimed to compare outcomes between ileo-/colorectal anastomosis and rectal stump procedure and to identify risk factors for RAL and blow-out. Method Data were retrospectively collected between 2012 and 2024 from a prospectively maintained HIPEC Registry and supplemented with the review of medical records. Postoperative complications and the prevalence of RAL or blow-out were registered. Pearson's chi-squared test was used to compare differences in categorical variables. Logistic regression was used to identify risk factors for RAL and blow-out. Results Among 1271 CRS-HIPEC procedures, 332 involved rectal resections. Patients received either an ileo-/colorectal anastomosis (n = 158) or had a rectal stump procedure (n = 174). RAL occurred in 5.7% and blow-out in 2.9% (p = 0.201). In the rectal stump group, patients were older (65 vs. 59 years; p = <0.001), had higher PCI scores (p = 0.031) and more often had received neoadjuvant treatment (p = 0.025). Logistic regression showed no independent association between RAL and type of rectal reconstruction (OR 1.99; 95% CI: 0.61–6.51), low anastomotic level (OR 2.17; 95% CI: 0.50–9.42) or peritoneal cancer index >21 (OR 6.47; 95% CI: 0.84–50.1). Conclusion Both reconstruction strategies following rectal resection in CRS-HIPEC were associated with low rates of RAL or blow-out. No independent risk factors were identified, indicating that the choice of surgical approach should be individualized based on clinical context rather than presumed leakage risk
Progestagens and progesterone receptor modulation : Effects on the brain, mood, stress, and cognition in females
No full textProgesterone is a highly lipophilic gonadal hormone that can influence behavior and mental health through its receptors in the brain. Fluctuations in progesterone levels across critical periods of a females life are associated with increased susceptibility to mental conditions. This review highlights the effects of progestagens, including progesterone and synthetic progestins, on the brain, mood, stress, and cognition in females. The primary focus is on experimental pharmacological research that teases out the distinct effects of progestagens from those of estrogens. Additionally, the key literature on puberty, the menstrual cycle, pregnancy, perimenopause, hormonal contraceptives, and menopausal hormone therapy is reviewed, although conclusions are limited by the nested effects of progestagens and estrogens. Single study-findings suggest an influence of progesterone on amygdala reactivity related to processing of emotional stimuli and memory. In patients with premenstrual dysphoric disorder, progesterone receptor modulation improves premenstrual mood symptoms and potentially enhances fronto-cingulate control over emotion processing. The interaction between progestagens and the systems involved in the regulation of stress seems to influence subjective experiences of mood and stress. Sparse studies investigating the effects of progestin-only contraceptives suggest effects of progestagens on the brain, mood, and stress. Progesterone and progestins used for contraception can influence neural processes as myelination and neuroprotection, exerting protective effects against stroke. Concerning menopausal hormonal therapy, the effects of progestins are largely unknown. Levels of progesterone as well as type, administration route, timing, dose regimen, metabolism, and intracellular activity of progestins in hormonal contraceptives and menopausal hormonal therapy are factors whose effects remain to be elucidated. Altogether, current knowledge highlights the potential role of progestagens in females health but also calls for well-designed pharmaco-behavioral studies disentangling the effects of progestagens from those of estrogens
Price predictability at ultra-high frequency : Entropy-based randomness test
No full textWe use the statistical properties of Shannon entropy estimator and Kullback-Leibler divergence to study the predictability of ultra-high frequency financial data. We develop a statistical test for the predictability of a sequence based on empirical frequencies. We show that the degree of randomness grows with the increase of aggregation level in transaction time. We also find that predictable days are usually characterized by high trading activity, i.e., days with unusually high trading volumes and the number of price changes. We find a group of stocks for which predictability is caused by a frequent change of price direction. We study stylized facts that cause price predictability such as persistence of order signs, autocorrelation of returns, and volatility clustering. We perform multiple testing for sub-intervals of days to identify whether there is predictability at a specific time period during the day.eSSENCE - An eScience Collaboratio
String musicians, playing related musculoskeletal disorder and physical activity
No full textBakgrund: Förekomsten av spelarrelaterad muskuloskeletal smärta (PRMD) är hög bland stråkmusiker. Prevalensen av PRMD är väl beforskad i andra delar av världen men svenska studier saknas. Det saknas kunskap om stråkmusikers fysiska aktivitet (FA) och hur sambandet med PRMD ser ut. Syfte: Syftet med denna studie var att kartlägga prevalensen av PRMD hos stråkmusiker mätt genom Musculoskeletal Pain Intensity and Interference Questionnaire for Musician’s (MPIIQM) och undersöka sambandet med graden av FA som de utfört mätt med International Physical activity Questionnaire - Short Form (IPAQ-SF). Metod: En kvantitativ tvärsnittsstudie genomfördes. 40 stråkmusiker deltog genom att besvara en enkät som bestod av en modifierad version av MPIIQM och IPAQ-SF. Resultat: 83% av deltagarna hade någon gång upplevt PRMD. FA-nivå var lägre än Världshälsoorganisationens (WHO) rekommendationer för FA för vuxna. Ingen statistiskt signifikant skillnad sågs mellan upplevd PRMD och grad av FA hos stråkmusiker som grupp. Män tränar mer på en vigorös nivå än kvinnor (p=0.047). Ingen signifikant skillnad i upplevd PRMD kunde hittas mellan könen. Ett svagt negativt samband mellan prevalensen av PRMD och grad av FA sågs (ρ=-0.270) till (ρ=0.044). Konklusion: Denna studie visar att upplevd PRMD förekommer i liknande utsträckning i svenska orkestrar som i orkestrar runt om i världen. Mer forskning behövs för att utreda PRMD:s samband med FA samt för att förstå uppkomsten av PRMD och för att utveckla förebyggande och behandlande fysioterapeutiska interventioner.Background: The prevalence of playing-related musculoskeletal disorders (PRMD) is high among string musicians. The prevalence of PRMD has been well-researched in other parts of the world, but Swedish studies are lacking. There is a lack of knowledge regarding the physical activity (PA) of string musicians and how it relates to PRMD. Purpose: The purpose of this study was to map the prevalence of PRMD among string musicians, measured using the Musculoskeletal Pain Intensity and Interference Questionnaire for Musicians (MPIIQM), and to investigate the relationship with the level of PA they engage in, measured with the International Physical Activity Questionnaire - Short Form (IPAQ-SF). Method: A quantitative cross-sectional study was conducted. Forty string musicians participated by completing a survey consisting of a modified version of the MPIIQM and IPAQ-SF. Results: Eighty-three percent of the participants had experienced PRMD at some point. The level of PA was lower than the World Health Organization (WHO) recommendations for PA for adults. No statistically significant difference was observed between perceived PRMD and the level of PA in the group of string musicians. Men engaged in more vigorous exercise than women (p=0.047). No significant difference in perceived PRMD could be found between genders. A weak negative correlation between the prevalence of PRMD and the level of PA was observed (ρ=-0.270) to (ρ=0.044). Conclusion: This study shows that perceived PRMD occurs to a similar extent in Swedish orchestras as in orchestras around the world. More research is needed to investigate the relationship between PRMD and PA, as well as to understand the onset of PRMD and to develop preventive and therapeutic physiotherapeutic interventions.
Tailored energy dissipation with viscoelastic architectured materials
No full textA family of architectured materials (AMs) is studied for viscous damping. A computational methodology is employed to capture the energetic behavior of the AM. While the presented approach is generic for any symmetry class of AMs, the selected Representative Volume Elements (RVEs) have cubic symmetry. In particular, the set of truss structures including simple cubic, body-centered cubic and face-centered cubic and the set of Triply Periodic Minimal Surfaces (TPMS) including Gyroid, Diamond and Schoen IWP are analyzed. First, a homogenization method is implemented to extract the effective viscoelastic behavior of the chosen AMs, verified based on the correspondence principle. Second, the energetic behavior including the storage and loss factors are extracted for different anisotropy directions of the lattices. And finally, in order to showcase the application of such tailored energy response under a class of loadings, the energy dissipation of the homogenized models of the different RVEs are elaborated under hydrostatic, tensile and shear modes. Interestingly, for the same base material and the same relative density, the different AMs show different energy dissipation behavior in hydrostatic, tensile and shear modes. This opens up an excellent library of materials for a tailored energy dissipation
Do mutations in parC contribute to collateral sensitivity development?
No full textTo mitigate resistance development in clinic settings, drug cycling programs based on collateral sensitivity have become an important research area. Collateral sensitivity is a phenomenon in which acquired resistance to one drug subsequently leads to increased sensitivity towards another one. In order to confidently use drug cycling in clinical settings research on specific resistance patterns is needed. In this study on Escherichia coli, I examined if parC mutations in ciprofloxacin resistant strains contributed to collateral sensitivity development towards gentamicin. Strains were made resistant by evolution in ciprofloxacin and by genetic engineering using lambda-red recombineering. Collateral sensitivity to gentamicin and ciprofloxacin resistance levels were determined for the acquired strains. Findings strongly suggest that mutations in parC do not contribute to collateral sensitivity towards gentamicin. However, deleting the genes acrR and marR from parC mutants seem to increase the sensitivity towards gentamicin. Additionally, other unknown mutations are most likely involved in the CS development. In conclusion, parC mutations do not confer collateral sensitivity towards gentamicin which makes drug cycling based on these conditions a less feasible option.