Modelling the environmental benefit of a lifetime extension on a laptop to facilitate pro-environmental behaviour

Consumption of household goods is one of the main drivers behind several environmental impacts, including emission of greenhouse gases. Lifetime extension has been proposed as a strategy to mitigate emissions. Keeping products in use through service and repairs can replace the need for new purchase and thereby reduce the overall impacts associated with material extraction, manufacturing, recycling and transport. In this thesis, a scenario model is developed to compare the environmental impacts of a base-scenario where a laptop s replaced after 4 years, which is the current average lifetime of laptops, with a lifetime extension scenario where an overhaul is performed after 4 years, giving the laptop 2 additional years. In addition, a consumer survey is performed on inhabitants of Ås municipality and students at the Norwegian University of Life Sciences to identify: a. whether consumers are aware of the environmental impacts associated with household goods, focusing on the greenhouse gas emissions from the production phase; and b. whether more information of the environmental impacts potentially can encourage consumers to pro-environmental behaviour. Results show a clear environmental benefit in the lifetime extension scenario, with a 20 percent difference in cumulative GHG-emissions over a 12 year period. Results from the survey indicate a low level of awareness among consumers of the environmental impacts associated with household goods, but at the same time the expressed belief that such information should be more available and that it can in fact influence behaviour in a pro-environmental direction. Building on the results, the development of a tool is proposed which can visualize the environmental and economic benefits of lifetime extension on a wider range of products in order to create awareness among consumers and stimulate to pro-environmental behaviour. Further research on lifetime extension of household goods is suggested

Experimental infection of cattle with ovine Dichelobacter nodosus isolates

BACKGROUND: Dichelobacter nodosus is the main causative agent of ovine footrot, and there are strong indications that the bacterium can be transferred to cattle grazing on the same pasture as sheep. The aim of this study was to investigate if benign and virulent D. nodosus strains isolated from sheep can be transferred to the interdigital skin of cattle under experimental conditions. Further, we wanted to observe the impact of such infection on bovine foot health, and test the effect of topical chlortetracycline (Cyclo spray(®): Eurovet) on the infection. FINDINGS: Six heifers were included in the study. After an initial 18-day maceration period, three heifers were inoculated on one single foot with a benign strain and three with a virulent strain by adding bacterial suspension in a bandage. The bandages were left on for 17 days, and when removed, D. nodosus was isolated from all six heifers. All six heifers developed interdigital dermatitis. In five of the heifers D. nodosus organisms were demonstrated within the epidermis. Twenty-four days after treatment with chlortetracycline all heifers were negative by cultivation, but tested positive for D. nodosus by polymerase chain reaction (PCR). Two of the six heifers still tested positive for D. nodosus by PCR 49 days after treatment. After 70 days, all heifers tested negative for D. nodosus. CONCLUSIONS: This study shows that both virulent and benign D. nodosus strains originating from sheep can be transferred to naïve heifers under experimental conditions. Further, the study supports the hypothesis that infections with virulent D. nodosus in cattle are associated with interdigital dermatitis. No conclusion regarding the treatment of D. nodosus infection with chlortetracycline was possible

Modeling, calibration and aberration correction for Fourier Ptychography within the paraxial approximation

Fourierptykografi (FP) er en metode for numerisk forbedret mikroskopi basert på iterativ rekonstruksjon av Fourier spekteret til en kompleks prøve, fra et antall lav-oppløste intensitet bilder tatt med et vanlig lys mikroskop under koherent belysning med variable vinkel. Gjennom FP, beholder man fordelene av et stort synsfelt og stor dybdeskarphet fra bruken av et mikroskop objektiv med lav forstørrelse, samtidig som det er mulig å oppnå økt oppløsning og kvantitativ fase-rekonstruksjon. For optimal rekonstruksjon innenfor FP rammeverket, er korrektheten til den underliggende avbildningsmodellen som benyttes under rekonstruksjonen viktig. De hovedbidragene i denne oppgaven er utledningen av en generell avbildningsmodell basert på paraksial optikk, presentasjonen av en kalibreringsprosedyre basert på opprinnelsen av direkte-lys regionen i den utledede modellen og en innledende undersøkelse av de negative konsekvensene ved å avbilde gjennom et vindu. I den utledede avbildningsmodellen, benyttes plasseringen av den definerende blenderåpningen i et linsesystem til å definere en effektiv avstand fra objektet til blenderåpningen. Basert på denne verdien, utledes behovet for å inkludere et kvadratisk fase-ledd i objekt planet, samtidig som frekvens skiftet under vinklet belysning blir posisjons avhengig. Ved avbildning gjennom et vindu, ble det demonstrert at bruken av et objektiv med høy numerisk aperture resulterer i kraftige aberrasjoner. For å unngå disse aberrasjonene, må et objektiv med lav numerisk aperture benyttes, hvilket samsvarer med styrkene til FP.Fourier Ptychography (FP) is a method of computationally enhanced microscopy based on iterative recovery of the Fourier spectrum of a complex sample, from a number of low-resolution intensity images obtained using a standard light microscope under coherent illumination at varying angles. Through FP, the benefits of a large field of view and depth of field obtained by using a low magnification microscope objective may be maintained, while simultaneously allowing for increased resolution and quantitative phase recovery. For optimal recovery within the FP framework, the correctness of the underlying diffraction model used during recovery is important. The main contributions in this thesis are the derivation of a generalized imaging model based on paraxial optics, the proposal of a system calibration scheme based on the origin of the bright-field region within the derived imaging model and an initial investigation into the detrimental effects of imaging through a window. In the derived imaging model, the placement of the defining aperture of the system was used to define an effective object to aperture distance. Based on this value, the appearance of a variable quadratic phase term at the object plane and a spatial variation of the frequency shift under angled illumination was derived. Upon imaging through a window, it was found that using a high numerical aperture objective results in severe aberrations. To avoid the aberrations, a low numerical aperture objective must be used, playing into the strengths of FP

Model predictive waypoint following for an UAV using end-time bisection

Ice surveillance is motivated by a need to improve the safty for shipping and offshore industries in the arctic waters. This thesis describes the implementation and simulation results for a model predictive controller (MPC) for a iceberg surveillance by UAV, using an end-time-based optimization scheme. The optimization scheme uses a bisection method to find the end-time over a series of smaller optimizations. This method was an improved version of a method devised in project work during the spring of 2015. The implementation of the MPC scheme and optimization algorithm is done in Python, using the sybolic framework Casadi. The model predictive controller performed well if the wind distubance on the UAV was known, since the wind could be coupled foreward by the optimal controller. It was found that the UAV could handle wind disturbances of more than half its own speed. However, in cases were parts of the wind disturbance was unknown, the simulated UAV would be blown off course since there was no integral effect in the control loop. The performance of the bisection method used on the end-time in the optimal controller found good solutions as long as the vehicle was some distance away from the target waypoints. Baring these two problems, the whole control system performed quite well. And with additions such as an wind estimator and a backup controller, which addresses these problems, the overall performance would be even better

Radiosensitization by the histone deacetylase inhibitor vorinostat under hypoxia and with capecitabine in experimental colorectal carcinoma

Background The histone deacetylase inhibitor vorinostat is a candidate radiosensitizer in locally advanced rectal cancer (LARC). Radiosensitivity is critically influenced by hypoxia; hence, it is important to evaluate the efficacy of potential radiosensitizers under variable tissue oxygenation. Since fluoropyrimidine-based chemoradiotherapy (CRT) is the only clinically validated regimen in LARC, efficacy in combination with this established regimen should be assessed in preclinical models before a candidate drug enters clinical trials. Methods Radiosensitization by vorinostat under hypoxia was studied in four colorectal carcinoma cell lines and in one colorectal carcinoma xenograft model by analysis of clonogenic survival and tumor growth delay, respectively. Radiosensitizing effects of vorinostat in combination with capecitabine were assessed by evaluation of tumor growth delay in two colorectal carcinoma xenografts models. Results Under hypoxia, radiosensitization by vorinostat was demonstrated in vitro in terms of decreased clonogenicity and in vivo as inhibition of tumor growth. Adding vorinostat to capecitabine-based CRT increased radiosensitivity of xenografts in terms of inhibited tumor growth. Conclusions Vorinostat sensitized colorectal carcinoma cells to radiation under hypoxia in vitro and in vivo and improved therapeutic efficacy in combination with capecitabine-based CRT in vivo. The results encourage implementation of vorinostat into CRT in LARC trials

Comparison of veterinary drugs and veterinary homeopathy: part 1

For many years after its invention around 1796, homeopathy was widely used in people and later in animals. Over the intervening period (1796-2016) pharmacology emerged as a science from Materia Medica (medicinal materials) to become the mainstay of veterinary therapeutics. There remains today a much smaller, but significant, use of homeopathy by veterinary surgeons. Homeopathic products are sometimes administered when conventional drug therapies have not succeeded, but are also used as alternatives to scientifically based therapies and licensed products. The principles underlying the veterinary use of drug-based and homeopathic products are polar opposites; this provides the basis for comparison between them. This two-part review compares and contrasts the two treatment forms in respect of history, constituents, methods of preparation, known or postulated mechanisms underlying responses, the legal basis for use and scientific credibility in the 21st century. Part 1 begins with a consideration of why therapeutic products actually work or appear to do so