Use of novel biomarkers (Homocysteine, vitamin B6, B9 and B12) on the assessing the progression of cardiovascular disease

A large number of evidences correlate elevated levels of homocysteine (Hcys) with a higher cardiovascular diseases (CVDs) risk, especially, atherosclerosis. Similarly, abnormal low levels of the vitamins B6, B9 and B12 are associated to an instability in the methionine cycle with an over production of Hcys. Thus, biomedical sciences are looking forward for a cheaper, faster, precise and accurate analytical methodology to quantify these compounds in a suitable format for the clinical environment. Therefore the objective of this study was the development of a simple, inexpensive and appropriate methodology to use at the clinical level. To achieve this goal, a procedure integrating a digitally controlled (eVol®) microextraction by packed sorbent (MEPS) and an ultra performance liquid chromatography (UPLC) coupled to a photodiode array detector (PDA) was developed to identify and quantify Hcys vitamins B6, B9 and B12. Although different conditions were assayed, we were not able to combine Hcys with the vitamins in the same analytical procedure, and so we proceeded to the optimization of two methods differing only in the composition of the gradient of the mobile phase and the injected volume. It was found that MEPS did not bring any benefit to the quantification of the Hcys in the plasma. Therefore, we developed and validate an alternative method that uses the direct injection of treated plasma (reduced and precipitated). This same method was evaluated in terms of selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), matrix effect and precision (intra-and inter-day) and applied to the determination of Hcys in a group composed by patients presenting augmented CVD risk. Good results in terms of selectivity and linearity (R2> 0.9968) were obtained, being the values of LOD and LOQ 0.007 and 0.21 mol / L, respectively. The intra-day precision (1.23-3.32%), inter-day precision (5.43-6.99%) and the recovery rate (82.5 to 93.1%) of this method were satisfactory. The matrix effect (>120%) was, however, higher than we were waiting for. Using this methodology it was possible to determine the amount of Hcys in real plasma samples from individuals presenting augmented CVD risk. Regarding the methodology developed for vitamins, despite the optimization of the extraction technique and the chromatographic conditions, it was found that the levels usually present in plasma are far below the sensitivity we obtained. Therefore, further optimizations of the methodology developed are needed. As conclusion, part of the objectives of this study was achieved with the development of a quick, simple and cheaper method for the quantification of Hcys.

A virtual agent to sustaining children's engagement in language learning

In this thesis we aimed to explore the potential of gamification - defined as “the use of game elements in non-game contexts” [30] - in increasing children's (aged 5 to 6) engagement with the task. This is mainly due to the fact that our world is living a technological era, and videogames are an example of this engagement by being able to maintain children’s (and adults) engagement for hours straight. For the purpose of limiting complexity, we only addressed the feedback element by introducing it with an anthropomorphic virtual agent (human-like aspect), because research shows that virtual agents (VA’s) can influence behavioural change [17], or even induce emotions on humans both through the use of feedback provided and their facial expressions, which can interpreted in the same way as of humans’ [2]. By pairing the VA with the gamification concept, we wanted to 1) create a VA that is likely to be well-received by children (appearance and behaviour), and 2) have the immediate feedback that games have, so we can give children an assessment of their actions in real-time, as opposed to waiting for feedback from someone (traditional teaching), and with this give students more chances to succeed [32, 43]. Our final system consisted on a virtual environment, where children formed words that corresponded to a given image. In order to measure the impact that the VA had on engagement, the system was developed in two versions: one version of the system was limited to provide a simple feedback environment, where the VA provided feedback, by responding with simple phrases (i.e. “correct” or “incorrect”); for the second version, the VA had a more complex approach where it tried to encourage children to complete the word – a motivational feedback - even when they weren’t succeeding. Lastly we conducted a field study with two groups of children, where one group tested the version with the simple feedback, and the other group tested the ‘motivational’ version of the system. We used a quantitative approach to analyze the collected data that measured the engagement, based on the number of tasks (words) completed and time spent with system. The results of the evaluation showed that the use of motivational feedback may carry a positive effect on engaging children.

Motivating the use of public transit through a mobile glanceable display

With increasing concerns about the impact of global warming on human life, policy makers around the world and researchers have sought for technological solutions that have the potential to attenuate this process. This thesis describes the design and evaluation of an information appliance that aims to increase the use of public transportation. We developed a mobile glanceable display that, being aware of the user’s transportation routines, provides awareness cues about bus arrival time, grounded upon the vision of Ambient Intelligence. We present the design process we followed, from ideation to building a prototype and conducting a field study, and conclude with a set of guidelines for the design of relevant personal information systems. More specifically we seek to test the following hypotheses: 1) That the tangible prototype that provides ambient cues will be used more frequently than a similar purpose mobile app, 2) That the tangible prototype will reduce the waiting time at the bus stop, 3) That the tangible prototype will result to reduced anxiety on passengers, 4) That the tangible prototype will result to an increase in the perceived reliability of the transit service, 5) That the tangible prototype will enhance users’ efficiency in reading the bus schedules and 6) That the tangible prototype will make individuals more likely to use public transit. In a field study, we compare the tangible prototype against the mobile app and a control condition where participants were given no external support in obtaining bus arrival information, other than their existing routines. Using qualitative and quantitative data, we test the aforementioned hypotheses and explore users’ reactions to the prototype we developed.