Publikationer från Umeå universitet
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Combined serine protease PRSS22 and CEA mRNA analysis identifies the majority of colon cancer patients that recur within 12 years
No full textIntroduction: Proteases play an important role in tumor progression. The predictive efficacy of proteases PRSS3 and PRSS22 mRNA levels for predicting relapse in surgically treated colon cancer (CC) patients was assessed. Methods: mRNA expression was quantified in 371 half lymph nodes (LNs) from 121 CC patients, 77 control LNs (13 patients), 66 primary colon tumors, and 30 normal colon tissues of these patients. Patients were also stratified according to their CEA mRNA level. The occurrence of relapse following curative surgery was evaluated using the Cox regression and Kaplan-Meier survival model analyses. Protein expression was examined through immunohistochemistry. Results: PRSS22 was superior to PRSS3 in identifying patients at risk of recurrence. Thus, high PRSS22 levels in LNs identified 76.5% of those who recurred, while PRSS3 only identified 17.6% of these patients and these were in TNM stages III and IV. The Kaplan-Meier analysis indicated that CC patients exhibiting elevated PRSS22 levels in lymph nodes experienced a reduction in survival time, averaging 37 months over the follow-up period (p = 0.009) and a 3-fold increased hazard risk (1.3–6.0; p = 0.01). In the group with low PRSS22 levels, only one patient experienced relapse at the 12-year follow-up when CEA mRNA analysis was included. A fraction of CEA-positive tumor cells expressed PRSS22 protein. Conclusion: The importance of the secreted serine protease, S1 family member PRSS22 in tumor progression is highlighted. It shows promise as a biomarker for CC prognosis and as a target to prevent tumor spread by inhibiting its enzymatic activity
Factors Influencing Digital Accounting Adoption in the Sri Lankan Apparel Sector : A Quantitative Study
No full textDigitalizing business processes is a major step forward for all organizations. Accounting is one of the key fields that has embraced digital adoption. In Sri Lanka, the apparel sector plays a vital role in the national economy, contributing significantly to the country’s Gross Domestic Product and employment. However, despite assessing its manufacturing efficiencies, limited research has been conducted to explore enhancements in accounting efficiency. With a view to addressing this gap, this study investigates the factors influencing digital accounting adoption in the Sri Lankan apparel sector and identifies the most significant among them. The study used a quantitative approach and integrated previous literature together the Technology–Organization–Environment (TOE) framework, which was important in information systems and accounting research. A structured questionnaire was distributed via email to 169 apparel companies operating in Sri Lanka, and a total of 128 valid responses were received from accounting, auditing, and finance professionals. The independent variables tested include expected benefits, facilitating factors, external influences, and adoption challenges, while digital accounting adoption was tested as the dependent variable. Four hypotheses were formulated and tested. Descriptive analysis, correlation analysis, and multiple regression techniques were applied using IBM SPSS 22.0 to examine the relationships between these factors and the level of digital accounting adoption. The findings revealed that facilitating factors strong and statistically significant positive influence on digital accounting adoption. External factors also showed a significant positive relationship. In contrast, while expected benefits and adoption challenges yielded positive and negative influences, respectively, their effects on digital accounting adoption were not statistically significant. Finally, the study contributes theoretically by contextualizing and extending the organizational (facilitating) and environmental (external) factors in a specific sector in a developing economy, i.e., the apparel sector in Sri Lanka. At the same time, practically, it guides apparel sector companies in Sri Lanka on enhancing digital accounting adoption through internal support and external alignment. Further, the study has limitations such as focusing only on one sector and, hence, generalizability limitations, the sample size is lower than recommended, and it does not examine the effect of demographic factors on digital accounting adoption
Strukturen hos Mars bogchock
No full textA shock forms when a supersonic flow meets an obstacle. The supersonic speed of the flow ensures that information of the obstacle cannot travel in the anti-flow direction to warn the flow of the obstacle, and as such there is no chance of the flow losing enough energy and momentum other than in the shock. Shocks are ubiquitous in the universe, for example forming during the outflow from supernovas, which contribute to distributing mass across the universe when particles are accelerated at these shocks. Due to the vast distances in our universe, the shocks of our solar system are our only in-situ laboratories for studying shocks. Because of the resemblance to the bow wave in front of a ship, we call the shocks in front of planets, comets, and moons bow shocks. This thesis studies the structure of the Martian bow shock and its dependence on external and internal factors. For this purpose, we have used spacecraft observations from the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission and from Mars Express, and numerical simulations using the kinetic hybrid model Amitis. In the first study, we use MAVEN data to quantify the width of the quasi-perpendicular Martian bow shock region and to study what factors affect it. We show that the magnetosonic Mach number, dynamic pressure, critical ratio, and overshoot amplitude affect the width. In the second study, we investigate the instantaneous asymmetry of the Martian bow shock using data from MAVEN. We use two methods, one single-spacecraft method, and one dual-spacecraft method. With the single-spacecraft method, we find an asymmetry with respect to the solar wind convective electric field. With the dual-spacecraft method, we find no significant asymmetry attributed to a specific cause, but we do observe strong asymmetry on a case by case basis. In the third paper, we present the first statistical study of jets in the Martian plasma environment using 10 years of MAVEN data. We find that jets in the Martian plasma environment are similar to jets observed in the terrestrial magnetosheath, with some notable differences such that for Martian jets the density enhancement dominates over the velocity enhancement. In the fourth study, using the hybrid model Amitis, we investigate what process brings the supersonic flow to subsonic for three different directions of the interplanetary magnetic field. We find that the more parallel the field becomes with respect to the flow direction, the more upstream disturbances form and scatter the impinging solar wind. This decreases the solar wind momentum toward Mars and leads to the planetary plasma expanding to distances past the location of the nominal shock location. In the fifth paper, we propose a space mission to Mars that would help answer many of the questions that cannot be answered with the data sets we have today.En chock uppstår när ett supersoniskt flöde möter ett hinder. Den supersoniska hastigheten hos flödet säkerställer att information om hindret inte hinner resa i motflödesriktning för att varna flödet om hindret, och på så sätt finns det ingen chans för flödet att förlora tillräckligt med energi och rörelsemängdsmoment förutom i en chock. Chockvågor är vanligt förekommande i universum, där de till exempel formas vid utflödet från supernovor, vilket leder till distribuering av massa i universum när partiklar accelereras vid dessa chockvågor. Tillföljd av de ofantliga avstånden i vårt universum så är chockvågorna i vårt solsystem våra enda insitu laboratorier för att studera chockar. På grund av deras likhet med bogvågor framför skepp, kallar vi chockarna framför planeter, kometer, och månar för bogchockar. Denna avhandling studerar strukturen hos Mars bogchock, och dess beroende på externa och interna faktorer. För detta ändamål har vi använt oss av rymdfarkostobservationer från MAVEN och Mars Express, och numeriska simulationer från den kinetiska hybridmodellen Amitis. I den första studien använder vi oss av MAVEN data för att kvantifiera bredden hos den Marsianska kvasi-vinkelräta bogchocken och för att studera vilka faktorer som påverkar den. Vi visar att det magnetosoniska Machtalet, dynamiska trycket, kritiska kvoten, och översvängningssamplituden påverkar bredden. I den andra studien undersöker vi den momentana asymmetrin hos den Marsianska bogchocken med hjälp av data från rymduppdragen Mars Atmosphere and Volatile EvolutioN (MAVEN) och Mars Express. Vi använder oss av två metoder, en enfarkostmetod och en tvåfarkostmetod. Med enfarkostmetoden finner vi asymmetri med avseende på solvindens konvektiva elektriska fält. Med tvåfarkostmetoden finner vi ingen signifikant asymmetri med avseende på de studerade faktorerna, men vi observerar stor asymmetri från fall till fall. I den tredje studien presenterar vi den första statistiska studen av plasmajetar vid Mars, där vi använder oss av 10 år av MAVEN data. Vi finner att jetar i Mars plasmamiljö liknar jetar i Jordens magnetskikt, med vissa anmärkningsvärda skillnader, så som att för Marsianska jetar så dominerar densitetsförhöjningen över hastighetsförhöjningen. I den fjärde studien, där vi använder den kinetiska hybridmodellen Amitis, undersöker vi vilken process som resulterar i att det supersoniska flödet blir subsoniskt för tre olika interplanetära magnetfältsriktningar. Vi finner att desto mer parallellt magnetfältet blir med avseende på flödesriktningen, desto fler störningar skapas uppströms om bogchocken och sprider ut den inkommande solvinden, vilket minskar solvindsrörelsemängdsmomentet mot Mars. Detta gör också att den planetära plasman expanderar till avstånd utanför det nominella bogchocksavståndet. I den femte studien så föreslår vi ett rymduppdrag till Mars som skulle hjälpa att besvara många av de frågor som inte kan bli besvarade med de dataset vi har idag
Survival mechanism of pancreatic tumor bacteria and their ability to metabolize chemotherapy drugs
No full textPancreatic cancer (PC) remains one of the most lethal malignancies, with limited treatment efficacy. While surgical resection is the most effective option, chemotherapy with agents such as 5-fluorouracil (5-FU) and gemcitabine may improve survival. Intraductal papillary mucinous neoplasms (IPMNs) are pancreatic cystic tumors and important precursor lesions frequently detected during PC screening. Emerging evidence suggests that IPMNs can harbor a distinct tumor microbiome, but the microbial persistence and potential influence on cancer treatment remain poorly understood. In this study, we analyzed bacterial isolates from clinical IPMN samples and investigated their interactions with chemotherapeutic agents using functional assays and whole-genome sequencing (WGS). We found that most isolates reduced the cytotoxic effect of 5-FU and gemcitabine on pancreatic cancer cell lines (PANC-1, AsPC-1, and Capan-2). WGS revealed that the Gammaproteobacteria strains were enriched in genes associated with antibiotic resistance, drug transport, and virulence compared to the Bacilli strains. Further pathway analysis showed that Gammaproteobacteria were enriched in pyrimidine metabolism pathways, while Bacilli were enriched in purine metabolism. These findings indicate that IPMN-associated bacteria are metabolically active and capable of modulating chemotherapy drug efficacy. Together, our findings suggest that the microbial adaptation mechanisms supporting bacterial survival within tumor lesions also enable them to interact with pyrimidine analogs. This underscores the importance of elucidating the functional roles of tumor-associated microbiota in modulating the tumor microenvironment and treatment efficacy
The epistemological significance of perceptual experiences : An analysis of Schellenberg’s constitutive approach
No full textDenna uppsats analyserar den epistemologiska betydelsen hos perceptuella erfarenheter utifrån Susanna Schellenbergs artikel The Epistemic Force of Perceptual Experience (2014).Uppsatsen analyserar Schellenbergs konstitutiva ansats, enligt vilken våra perceptuella kapaciteter – förmågan att särskilja objekt i omvärlden - bidrar till epistemologiskt berättigande. En central del i argumentation är att hallucination endast kan förstås i ljuset av veridisk perception och därmed slutleder Schellenberg att perceptuella erfarenheter bär på en inbyggd epistemologisk kraft tack vare sin metafysiska struktur. Uppsatsen tar även upp andra omkringliggande teorier för att visa hur Schellenbergs syn särskiljer sig från och integrerar medvetandeteoretiska och epistemologiska perspektiv. Slutligen föreslås att perceptuella erfarenheters epistemologiska betydelse skall analyseras genom ett holistiskt ramverk där perceptuella kapaciteter står i relation till omvärlden.This thesis examines the epistemological significance of perceptual experiences through an analysis of Susanna Schellenberg’s article The Epistemic Force of Perceptual Experience(2014). The thesis defends Schellenberg’s constitutive approach, which holds that our perceptual capacities – the ability to discriminate objects in the external world – play a central role in epistemic justification. A key element in her argument is that hallucinations can only be understood in the light of veridical perception and thereby concludes that perceptual experiences inhabit an epistemological force due to its metaphysical structure. The thesis critically investigates this connection and evaluates whether perceptual function and structure can justify beliefs. It further compares competing epistemological frameworks and proposes that the epistemic role of perceptual experience is best understood within a holistic model, where perceptual capacities are intrinsically linked to the external world
Spirituality, a new faith? : A multidisciplinary literature study on the concept of spirituality and related discourses
No full textDet går att observera ett ökat intresse för andlighet i Sverige. Antalet individer som uttrycker att de är ”andlig, men inte religiös” ökar. Studiens syfte var att studera det nyare forskningslitteratur säger om andlighet. Samt hur det relateras till religion. Studien resulterade entydigt i att andlighet idag ses i ett positivt perspektiv. Fyra olika diskurser kring andlighetens relation till religion presenterades: fristående från, delvis delad samt likvärdiga i två olika former. Hermeneutisk tolkning och diskursanalys utgjorde metoden. Empirin utgjordes av 17 tvärvetenskapliga artiklar. Empirin bestod främst av sekundärkällor. Ingen av artiklarna var skrivna av svenska forskare. Slutsatsen av studien är att andlighet inte kan ses som en ny trosriktning. Andlighet är ett äldre, komplext och diskursivt begrepp. Den nya positiva diskursen gällande andlighet uppmanar till integration av icke-evidensbaserade synsätt i forskningssammanhang. Avsaknaden av svensk forskning parallellt med den unika svenska kontexten uppmuntrar till ökat svenskt intresse, inom religionspsykologi och religionssociologi
Pathology of three ALS patients with FUS variants, including one likely benign Q23L variant lacking FUS inclusions
No full textFused in sarcoma (FUS) is an RNA-binding protein implicated in juvenile amyotrophic lateral sclerosis (ALS). Mutations in the FUS gene, particularly those affecting the nuclear localization signal (NLS), impair nuclear import and lead to cytoplasmic accumulation of FUS inclusions in motor neurons. However, the pathological and clinical significance of FUS variants outside the NLS remains less understood. Here, we describe clinical and histopathological findings from three ALS patients carrying FUS variants: two with NLS-region variants (R495X and P525L), and one with a variant in the N-terminal region outside the NLS (Q23L). The patients carrying NLS variants presented with aggressive, juvenile-onset spinal and bulbar ALS, characterized primarily by lower motor neuron involvement and rapid disease progression. In contrast, the Q23L patient exhibited a slowly progressive disease course, with predominantly upper motor neuron signs. Neuropathological analysis revealed cytoplasmic FUS inclusions in motor neurons of patients with NLS variants, consistent with typical FUS pathology. In contrast, the Q23L patient lacked FUS inclusions and instead displayed pTDP-43 pathology in the hippocampus, neocortex (including the motor cortex), nucleus olivaris, lentiform nucleus, striatum, and some lower motor neurons. Taken together, these results suggest that Q23L is most likely a benign variant. As antisense oligonucleotides (ASOs) targeting FUS are currently being explored in clinical trials, further neuropathological investigations are needed to determine whether ASO-mediated FUS silencing would be effective for patients carrying FUS variants outside the NLS region
Kernelbaserade approximationer för partikelmassfördelning
No full textAtmospheric particles affect public health, visibility, and the value of environmental forecasts used by authorities and industry. Models that accurately and quickly convert particle simulations into concentration maps enable faster, better-informed decisions during pollution episodes, fires, or chemical releases. In this thesis, we are in particular interested in the natural phenomena known as atmospheric dispersion. This is the study of how particles, such as dust, smoke, or pollutants, move or spread throughout the air. The movement of each individual particle through the atmosphere can be simulated, but that has the issue of quantity. It is unrealistic to propagate hundreds of thousands, or millions, of particles in a simulation to understand their collective behavior. If we are interested in particle concentration over a domain, rather than the individual particles positions, we can use single particles to represent clusters, or groups, of particles. This speeds up propagation, but introduces the need for a post-processing step to reconstruct the mass distribution, and a naive implementation of the post-processing can become excruciatingly slow. The purpose of this thesis is to propose improvements to this post-processing by introducing a few approximation methods, and evaluating any tradeoff between their accuracy and speed. To address the bottleneck that is post-processing, we implement and compare kernel-based post-processing methods for estimating concentration fields from representative particles. The study evaluates three discretizations (uniform grid, quadtree, k-d tree), a Gaussian kernel density estimator with three truncation schemes (square, dual-square, section subdivision), trapezoidal mass averaging, and two levels of hardware parallelization (multithreading and SIMD lane parallelization). Methods are tested on synthetic scenarios (random, centered, cone) and assessed using relative mass and distribution error metrics together with runtime measurements across sweeps of particle count, bandwidth h and truncation distance Tlim. Results show multithreading gives large speedups and lane parallelization yields further improvements for compatible meth-ods, and truncation dramatically increases speed by reducing the number of kernel evaluations but introduces an accuracy–speed tradeoff (a pragmatic choice of Tlim/h = 2 is used). The adaptive quadtree provides the best accuracy–performance balance for clustered scenarios. Meanwhile, the present k-d tree implementation produces unacceptably large mass distribution errors due to oversized cells. We conclude that with targeted algorithmic and memory-layout refinements (per-axis truncation, sparse section mapping, redesign of k-d cell placement) and validation on empirical datasets, the proposed approach can become a practical, efficient post-processing tool for FOI’s particle-dispersion simulation pipeline
Cobalt and zinc columbite compounds as new anode materials for Na-ion batteries
No full textNiobium-based oxide anode materials are promising anode materials for sodium ion batteries because of their high structural stability, safety, fast energy storage kinetics, and promising capacity. In this work, niobate compounds of the columbite type, ANb2O6 (A = Co2+ and Zn2+), prepared by a facile sol-gel method, are investigated as new anode materials for sodium ion batteries. The poor intrinsic electronic conductivity of the niobate anode materials is successfully overcome by coating the active materials with carbon in order to enhance Na-ion transport and storage. High-resolution transmission electron microscopy images reveal uniform coating of the carbon layer around the active particles to prevent agglomeration in both materials. While the carbon-coated material CoNb2O6 (CNO) at a current density of 25 mA g−1 delivered a high reversible capacity of 295 mA h g−1, the carbon-coated ZnNb2O6 (ZNO) material yielded 262 mA h g−1. However, the ZNO material delivered a significant cycling stability at a current density of 200 mA g−1, which corresponds to a capacity retention of 72% after 50 cycles. The difference in their electrochemical performances is related to the structural defects, specific surface areas, charge transfer resistances during charge-discharge cycles, Na+-ion diffusion coefficients, and the contribution of capacitive and diffusive behaviours to the total capacity. The present work not only introduces columbite compounds as anode materials with promising electrochemical properties but also provides insights into the development of potential anode materials for sodium ion battery technology and offers the foundation for designing new electrode materials with enhanced ion-diffusion pathways
A global database of soil microbial phospholipid fatty acids and enzyme activities
No full textSoil microbes drive ecosystem function and play a critical role in how ecosystems respond to global change. Research surrounding soil microbial communities has rapidly increased in recent decades, and substantial data relating to phospholipid fatty acids (PLFAs) and potential enzyme activity have been collected and analysed. However, studies have mostly been restricted to local and regional scales, and their accuracy and usefulness are limited by the extent of accessible data. Here we aim to improve data availability by collating a global database of soil PLFA and potential enzyme activity measurements from 12,258 georeferenced samples located across all continents, 5.1% of which have not previously been published. The database contains data relating to 113 PLFAs and 26 enzyme activities, and includes metadata such as sampling date, sample depth, and soil pH, total carbon, and total nitrogen. This database will help researchers in conducting both global- and local-scale studies to better understand soil microbial biomass and function