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Senast publicerade

Assessing potential causality between blood metabolites and primary sclerosing cholangitis using two-sample Mendelian randomization
ROSENGREN, OLA
Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease with a poorly understood aetiology. An observational study by Molinaro et al. have suggested an association between blood circulating metabolites and PSC, however, causal inference is limited by confounding and reverse causation. The aim of this study was to assess potential causal effects of blood circulating metabolites on PSC risk using Mendelian randomization (MR), and to compare the findings to the associations found in the observational study. Atwo-sample MR framework was applied using summary statistics from genome-wide association studies (GWAS) of PSC-associated metabolites and PSC. Instrumental variables (IVs) were selected based on genome-wide significance and linkage disequilibrium pruning. Causal effects were estimated using the inverse variance weighted method, with sensitivity analysis performed to assess heterogeneity and horizontal pleiotropy. MR analysis were conducted for seven metabolites previously associated with PSC and seven control metabolites with no association. Overall, the selected IVs explained only a small proportion of variance in metabolite levels, as reflected by low F-statistics, indicating weak instrument strength and a potential bias of causal effect estimates towards the null. No evidence of a causal effect was detected for either PSC-associated metabolites nor the control metabolites. Sensitivity analysis indicated moderate heterogeneity with little evidence of horizontal pleiotropy. These findings suggest that currently available IVs for the blood circulating metabolites are insufficient to robustly assess causality in PSC. While no causal effects were detected, this study highlights important limitations in metabolite-based MR and underscores the need for larger and more powerful metabolite GWAS to enable reliable causal inference.
App-Operated Robot with Live Streaming and environmental sensor
(2026) Firuzian, Reza
Being in inaccessible or dangerous environments requires remote controlled observation and control systems. This report describes the steps necessary for connecting various hardware components to each other and the software required to combine the hardware and software into a functioning system. This project presents the construction and implementation of an app-operated mobile robot capable of navigating different terrains, providing live video and image capture, and measuring ambient temperature. The system is built around a Jetson Orin Nano and integrates multiple hardware components, including a motor driver, motors, cameras, an environmental sensor and a 4G modem for remote communication. A server running on the robot handles video streaming, motor control commands, sensor data transmission, while a customdeveloped mobile application enables real-time monitoring and remote control. The robot was developed in a modular manner, allowing individual features to be implemented and tested incrementally. The results show successful remote control, live video streaming, and temperature monitoring, although communication instability due to the 4G modem affected latency and control responsiveness. Overall, the project demonstrates the feasibility of integrating hardware and software into a functional remotely operated robotic platform and provides a foundation for future enhancements.
Återtagning av små fastvingsdrönare i sjöräddningsmiljö
Bergman, Andreas
This thesis work was conducted in collaboration with Sjöräddningssällskapet (SSRS), which utilizes unmanned aerial vehicles (UAVs) to support maritime rescue operations. In coastal environments with small landing space and variable wind conditions, conventional landing methods for fixed-wing UAVs are not always suitable. The objective of this project was therefore to develop a conceptual system for safe mid-air capture and retrieval of a small fixed-wing UAV adapted to SSRS operational requirements. The work followed a structured product development process. After establishing system requirements and performing a functional analysis, solution principles were generated using a morphological matrix. Partial solutions and overall concepts were reduced through a systematic elimination process, excluding technically unsuitable or impractical alternatives. The remaining concepts were further analysed with respect to energy absorption, feasibility, and operational applicability. The final concept consists of a portable, modular capture system based on mechanical energy absorption through a tensioned line between two interconnected units. The system is dimensioned according to the UAV’s kinetic energy at approach, enabling a compact design compared to large-scale commercial systems. Analytical calculations indicate that the concept is feasible at a conceptual level and capable of handling the expected loads. The study demonstrates that an established capture principle can be scaled and adapted to maritime rescue applications through systematic concept development. Future work should include prototype development and experimental validation under realistic operating conditions.
Linjärt eller cirkulärt installationselement? Livscykeltänkande i praktiken
(2026) Meherdel, Najib; Naggar, Rani
Klimatförändringarna är en av vår tids största globala utmaningar. För att bromsa utvecklingen och minska utsläppen av växthusgaser har Europeiska unionen (EU) tagit fram en omfattande klimat- och miljöpolitik. I centrum för omställningen står den europeiska gröna given som har som mål att EU ska bli klimatneutralt senast 2050 (EU-kommissionen, 2023). Ett viktigt verktyg är livscykeltänkande som är ett tankeverktyg för att utvärdera produkter och tjänsters miljöbelastning och en utgångspunkt för cirkulärekonomi. I en cirkulärekonomi förväntas produkter, material och resurser cirkulera länge i produktionssystemen genom att återanvändas, repareras och återvinnas. (Naturvårdsverket, 2023). Byggsektorn har en särskilt stor påverkan på både klimat och resurser. Den kallas ofta för 40% branschen, skapar 40% avfall, använder 40% av energin och använder 40% av materialen. I Sverige står byggbranschen för omkring 22 procent av växthusgasutsläppen och producerar ungefär en tredjedel av allt avfall (Boverket, 2025). Här spelar tekniska installationer, som ventilation, VVS och el, en nyckelroll. Systemen byts ofta ut flera gånger under en byggnads livslängd, men är i dag sällan utformade för att kunna återbrukas eller återvinnas effektivt. Syftet med studien är att analysera hur produkterna kan miljöanpassas, med målet att identifiera möjliga designförändringar som underlättar framtida reparationer, demontering och återanvändning. För att nå detta syfte har en kvalitativ intervjustudie genomförts med intressenter som på olika sätt är involverade i produktlivscykeln exempelvis tillverkarföretag, teknikkonsulter och fastighetsförvaltare. Studien är avgränsad till aktörer verksamma inom byggbranschen i Göteborgsregionen, vilket ger ett lokalt perspektiv på både utmaningar och möjligheter i den cirkulära omställningen. En viktig slutsats från studien är att många installationselement i dag är utvecklade för ett linjärt användande, där produkterna används en gång och sedan kasseras. Det gör det svårt att demontera dem utan att de skadas, samtidigt som det ofta saknas tydlig dokumentation om vilka material som ingår. För att skapa cirkulära system behöver LCT (livscykeltänkande) tillämpas
Structural Investigation of an Alternative Cordwood Binder
(2026) Stålhammar, Olof
Cordwood masonry is a vernacular building technique that utilizes short pieces of wood in a binder matrix. The binder matrix used today is usually cement, lime-mortar or clay all with various downsides including thermal bridging, high environmental impact or difficulties of separating the materials at end of life. A novel binder made of a mixture of starch-based glue, lignin and saw dust is investigated to determine if the mechanical properties make it suitable to serve as an alternative. Samples of the binder are tested experimentally to find how it reacts to an outdoor environment and compressive strength. The parameters are used to develop a model of a wall element for FE-analysis that is compared with calculations based on Eurocode to verify the suitability of the material. This thesis found the best binder candidate to be one with two parts lignin and one part saw dust. This binder has a compressive strength of 0.4 N/mm2 and a modulus of elasticity of 13.7 N/mm2. This is sufficient for walls in a one-story building according to both the Eurocode calculations and the FE-model. This binder candidate withstood the weather during the three-month trial with only little damage while other candidates partially dissolved after 30-40 days in an exposed environment. The binder performed even better in a semi-sheltered environment, with little to no visible damage.