1 |
A prickly situation: Prickle1 function depends on the signaling contextYang, Tian 01 December 2013 (has links)
The gene PRICKLE1 is important for human brain function, as mutations in PRCKLE1 are associated with progressive myoclonus epilepsy (PME). Mutations in prickle orthologs could cause seizures in flies, zebrafish and mice, suggesting a conserved role of Prickle protein in seizure from fruit flies to humans. The underlying molecular mechanism how PRICKLE1 mutation causes PME is still unknown.
Prickle1 is part of the planar cell polarity (PCP) pathway, which regulates cell polarity within plane of cell sheets. In Drosophila, prickle is recruited to one side of the cell by another PCP protein, Van Gogh. This asymmetric protein localization of Van Gogh/prickle establishes cell polarity. In zebrafish and Xenopus, loss of Prickle or Van Gogh like (Vangl) genes causes PCP phenotypes, which seemingly supports the Prickle/Vangl protein interaction and the role of Prickle in PCP pathway.
The function of Prickle in mammals has not been analyzed. It is possible that mammalian Prickle also interacts with Vangl to mediate PCP signaling based on the conserved role of prickle from Drosophila to Xenopus. If Prickle1 interacts with Vangl and regulate PCP pathway, the PME we observed in humans might be associated with loss of neuronal polarity and impaired neuron activity. Therefore, to understand whether Prickle1 mediates Vangl signaling in mammals could be a step toward revealing the etiology of PME in human patients.
Therefore, I analyzed the function of Prickle1 in three developmental processes, the limb development, the palate development, and the caudal migration of facial branchimotor neurons (FBMs), in which the function of PCP pathway, especially Vangl2, has been described. Supporting the interaction between Prickle1 and Vangl, mutations in either Prickle1 or Vangl2 leads to shorter limbs. However, Prickle1 and Vangl2 only have limited overlap in mRNA expression in the digit tips. This raises the question as to how impaired Prickle1/Vangl2 protein interaction in these cells in the digit tips cause defective growth of the whole limb. It also suggests alternate function of Prickle1 other than mediating Vangl2 function.
This interaction between Prickle1 and Vangl2 is further challenged by the limited function of Vangl but the essential role of Prickle1 in palate development, which suggests that the function of Prickle1 is independent of Vangl2.
In the caudal migration of FBMs, Prickle1 mutation impairs this migration process dose-dependently. This is different from Vangl2 mutation, which completely blocks the caudal migration and partially impairs the lateral migration of FBMs. More importantly, Prickle1 is expressed by the neurons, while Vangl2 functions in the surrounding cells, which again raises the question as to whether and how the two proteins could interact if they are not expressed in the same cell.
These results together question the model that Prickle1 is the intracellular partner of Vangl2, but support Prickle1 function might be independent of Vangl. Actually, it is possible that Prickle1 is part of gene expression regulation machinery: Prickle1 mutation affects Wnt5a expression in the limb and Shh expression in the palate. Although this regulation mechanism is still unknown, it suggests that defective gene expression might be related to PME caused by PRICKLE1 mutation.
|
2 |
Ett gränssnitt för en lättare användning : En kvalitativ studie om en mobilspårningsapplikations gränssnitt och vilka element som behöver utvecklas / An interface for easier use : A qualitative study of a mobile tracking application's interface and the elements that need to be developedOlin, Joakim, Wahlgren, Bryan January 2022 (has links)
I takt med att ägandet av smartphones ökat samt att tekniken utvecklats så har det blivit allt mer förekommande med spårning av GPS-enheter. Användningen innefattar flera områden som exempelvis berör spårning av djur, fordon och människor. Tidigare forskning har främst fokuserat på de tekniska aspekterna med GPS och i flera av dessa källor nämns kortfattat att de mobila gränssnitten har fått kritik från studiernas deltagare och ansetts vara svåra att använda. Syftet med studien var att öka förståelsen för hur spårningsapplikationers gränssnitt kan utformas för att bli mer användarvänliga. Att genom ett användarcentrerat arbete kartlägga vilka element i nuvarande gränssnitt som kan förbättras för att underlätta användares kognitiva belastning vid användning. Studien hade en kvalitativ ansats och data samlades in genom intervjuer med erfarna användare av spårningsapplikationen Go. Det var Go-applikationens gränssnitt som undersöktes i studien. För att kunna besvara forskningsfrågan användes Foggs beteendemodell, UX och informationsarkitektur för att skapa intervjufrågor samt för att analysera och diskutera resultaten. Studiens resultat är inte generaliserbart eftersom urvalet var för litet och ej slumpmässigt framtaget. Därmed gav studiens resultat endast en första inblick av vilka element i gränssnittet som var i behov av att utvecklas för att förbättra spårningsapplikationens gränssnitt. Studien visade att informanterna var tillräckligt motiverade och att det framför allt var förmågan som behövde ökas och att det i vissa fall behövdes triggers. De element i gränssnittet som behövde utvecklas var historiken, larm, platsmarkörer, inställningar, informationssidan och livespårning. Tillvägagångssätten för att utveckla dessa element berör oftast ett grafiskt tydliggörande eller förklarande. / As the usage of smartphones has increased and the technology also has developed, it has become increasingly common with tracking of GPS devices. The usage includes multiple areas such as tracking of animals, vehicles, and people. Early research has mainly focused on the technical aspects with GPS and in a few of these sources it is briefly mentioned that mobile interfaces have been criticized by the study participants and are considered difficult to use. The purpose of this research was to increase the understanding on how tracking applications interface can be designed to be more user friendly. Through a User-Centered work to map how elements and functions in a current interface can improve to ease the users cognitive load during usage. The research had a qualitative approach and the data that was collected through interviews with experienced users of the tracking application Go. It was the interface of Go that was being studied during the research. To answer our research question, Fogg's behavior model was used together with UX and information architecture to create questions for the interviews and to analyze the results. Results of this research are not generalizable since the sample was small and not randomly selected. Hence, the results of the research provided a first insight of which elements in the interface that need development to improve the interface of tracking applications. The research showed that the informants are motivated enough and that it was primarily their ability that needed to be increased and, in some cases, triggers were needed. The elements on the interface that needed to be developed were, the history, the alarm, placemarks, settings, information page and live tracking. The approach to develop the elements often touches on a graphical clarity or explanatory note.
|
3 |
Spelifiering av kulturarv : En kvalitativ studie om att skapa engagemang kring Sveriges kulturarv / Gamifying Cultural Heritage : A qualitative study about creating engagement towards Sweden's cultural heritageEmil, Jadelius, Rasmus, Svensson January 2021 (has links)
Introduktion: Besöksnäringen är en växande sektor i Sverige, där kulturarv utgör en central del för att förmå skapa attraktiva besöksmål. Trots detta finns det fortfarande många kulturarv som inte synliggörs och därmed förblir outnyttjade resurser för städer och landsbygd. En växande trend inom besöksnäringen är spelifiering, vilket potentiellt bidrar till en rolig och personlig upplevelse och samtidigt ett synliggörande av många besöksmål som kan vara svåra att finna. Det finns dock begränsad forskning för spelifiering inom turism och än mindre om spelifiering av kulturarv. Syfte: Studiens syfte är att kartlägga vilka komponenter inom en spelifiering som initialt kan inneha betydelse för att skapa ett intresse hos användare att utforska kulturarv. Studien utgick ifrån forskningsfrågan: Hur kan spelifieringen för platsbaserade mobila applikationer som uppmärksammar kulturarv utformas för att attrahera nya användare och motivera dessa till användning? Litteraturstudie: Litteraturstudien behandlar spelifiering och Foggs beteendemodell. Spelifiering är användandet av spelelement inom kontexter som traditionellt inte hör samman med spelande och handlar om att motivera individer med målet att göra så många som möjligt till vinnare. Foggs beteendemodell påvisar att mänskligt beteende är ett resultat av tre element: Motivation - Drivkraft till handling; Förmåga - Kapacitet till handling; Trigger - Utlösande faktor till handling. Metod: Studien har en kvalitativ ansats med utgångspunkt i fältet för användarcentrerad design. Först tillämpades en heuristisk utvärdering ämnad för spelifierade tjänster, som sedan kompletterades med kvalitativa intervjuer där potentiella användare involverades för att uppmärksamma deras behov. Resultat: Resultaten visar att nyfikenhet och viljan att utforska är två drivande motivationsfaktorer. Det påvisas även att den information som presenteras i samband med kulturarv är central för att skapa engagemang kring kulturarv. Utmaningar i form av frågesport är ett uppskattat inslag men det är viktigt att frågor har en koppling till berört kulturarv och att det finns en varierad svårighetsnivå för att tillgodose både novisa och erfarna användare. Det finns ett behov av sociala inslag där det går att interagera med vänner genom gruppaktiviteter eller utmaningar. Sociala inslag bidrar även till att användare triggar varandra till att upptäcka kulturarv. Slutsats: För att lyckas skapa spelifierade lösningar som uppmärksammar kulturarv måste det som presenteras inneha mening för användare. / Introduction: The tourism industry is a growing sector in Sweden, of which cultural heritage is central to create attractive destinations. Despite this, there are still many cultural heritage sites that are not visible and thus remain unutilized resources for cities and the countryside. A growing trend in the tourism industry is gamification, which potentially contributes to a fun personal experience while increasing the visibility of many destinations that can be difficult to find. However, there is limited research on gamification in tourism and even less on gamification applied to cultural heritage. Purpose: The purpose of the study is to identify which components within a gamification that can initially be important for generating an interest in users to explore cultural heritage. The study intends to answer the following research question: How can the gamification for location-based mobile applications that pay attention to cultural heritage be designed to attract new users and motivate them to use? Literature study: The literature study delves into gamification and Fogg's behavior model. Gamification is the use of game elements in contexts that are not traditionally associated with gaming and is about motivating individuals with the goal of making as many as possible winners. Fogg's behavior model demonstrates that human behavior is the result of three elements: Motivation - Driving force to action; Ability - Capacity for action; Trigger - Triggering factor to action. Method: The study has a qualitative approach based on user-centered design. First, a heuristic evaluation intended for gamified services was applied, which was then supplemented with qualitative interviews where potential users were involved to pay attention to their needs. Results: The results show that curiosity and the willingness to explore are two driving motivational factors. It is also shown that the information presented in connection with cultural heritage is central to creating motivation around cultural heritage. Challenges in the form of quizzes are an appreciated element, but it is important that questions have a connection to the cultural heritage and that there is a varied level of difficulty to satisfy both novice and experienced users. There is a need for social elements where it is possible to interact with friends through group activities or challenges. Social elements also contribute to users triggering each other to discover cultural heritage. Conclusion: To succeed in creating gamified solutions that pay attention to cultural heritage, what is presented within the solution must be meaningful to the user.
|
4 |
Fractional Brownian motion and dynamic approach to complexity.Cakir, Rasit 08 1900 (has links)
The dynamic approach to fractional Brownian motion (FBM) establishes a link between non-Poisson renewal process with abrupt jumps resetting to zero the system's memory and correlated dynamic processes, whose individual trajectories keep a non-vanishing memory of their past time evolution. It is well known that the recrossing times of the origin by an ordinary 1D diffusion trajectory generates a distribution of time distances between two consecutive origin recrossing times with an inverse power law with index m=1.5. However, with theoretical and numerical arguments, it is proved that this is the special case of a more general condition, insofar as the recrossing times produced by the dynamic FBM generates process with m=2-H. Later, the model of ballistic deposition is studied, which is as a simple way to establish cooperation among the columns of a growing surface, to show that cooperation generates memory properties and, at same time, non-Poisson renewal events. Finally, the connection between trajectory and density memory is discussed, showing that the trajectory memory does not necessarily yields density memory, and density memory might be compatible with the existence of abrupt jumps resetting to zero the system's memory.
|
5 |
A Study on the Estimation of the Parameter and Goodness of Fit Test for the Self-similar ProcessChiang, Pei-Jung 05 July 2006 (has links)
Recently there have been reports that certain physiological data seem to have the properties of long-range correlation and self-similarity. These two properties can be characterized by a long-range dependent parameter d, as well as a self-similar parameter H. In Peng et al (1995), the alteration of long-range correlations with life-threatening pathologies are studied by analyzing the heart rate data of different groups of subjects. The self-similarity properties of two well-known processes, namely the Fractional Brownian Motion (FBM) and the Fractional ARIMA (FARIMA), are of interest to see if it is suitable to be used to model the heart rate data in order to examine the health conditions of some patients. The Embedded Branching Process (EBP) method for estimating parameter $H$ and a goodness of fit test for examining the self-similarity of a process based on the EBP method are proposed in Jones and Shen (2004). In this work, the performance of the goodness of fit test are examined using simulated data from the FBM and FARIMA processes. A modification of the distribution of the test statistics under null hypothesis is proposed and has been modified to be more appropriate. Some simulation comparisons of different estimation methods of the parameter $H$ for some FARIMA processes are also presented and applied to heart rate data obtained from Kaohsiung Veterans General Hospital.
|
6 |
Hur beteendeförändringsmodeller kan appliceras i skapandet av en informativ teknisk tjänst i syfte att minska svinn av grönsaker / How can behavior change models be applied in the design process of an informative technical service in order to reduce wastage of vegetables?Berglund, Anne January 2021 (has links)
Denna kandidatuppsats undersöker hur beteendeförändringsmodellerna “The Behaviour Change Wheel” (BCW), “BCT-Taxonomin” och ”Foggs Behavioural Model” (FBM) kan appliceras i skapandeprocessen av en informativ teknisk tjänst, i syfte att uppnå positiv beteendeförändring gällande svinn av grönsaker hos individer som är medlemmar av andelsjordbruk. I studien undersöks bland annat om deltagarna upplever att den informativa tekniska tjänsten leder till positiv skillnad i beteenden gällande grönsakssvinn, samt vilka specifika komponenter från beteendeförändringsmodellerna som de upplever gör skillnad. Genom semistrukturerade intervjuer och en analys genom beteendeförändringmodellerna identifieras brister i respondenternas beteenden gällande ett minskat grönsakssvinn. Baserat på analysen länkas lämpliga komponenter från beteendeförändringsmodellerna, som tillsammans med data från intervjuerna är grunden till en webbaserad prototyp med informativa inlägg. Ett användartest utfördes under en veckas tid, som avslutades med enkäter av kvantitativ och kvalitativ form för att ta reda på huruvida det skett en förändring i användarnas beteende samt vilka komponenter från beteendeförändringsmodellerna som användarna upplevde gjorde skillnad. Resultatet visar bland annat att ungefär hälften av användarna upplevde ett minskat grönsakssvinn under användartestet, samt att majoriteten upplevde att de identifierade bristande beteenden till viss del höjdes. / This bachelor thesis investigates how the behavior change models “The Behavior Change Wheel” (BCW), “The BCT-Taxonomy” and “Foggs Behavioral Model” (FBM) can be applied in the design process of an informative technical service, with the purpose to achieve positive behavior change regarding vegetable wastage in individuals who are members of Community Supported Agriculture. The study examines, among other things, whether the participants experience that the informative technical service leads to a positive difference in behaviors regarding vegetable waste, and which specific components from the behavior change models that they experience make a difference in the behaviours. Through semi-structured interviews and an analysis through the behavior change models, deficiencies in the respondents' behaviors regarding a reduced vegetable waste are identified. Based on the analysis, appropriate components are linked from the behavior change models, which together with data from the interviews form the basis for a web-based prototype with informative posts. A user test was performed during a week, which ended with surveys of quantitative and qualitative form to find out whether there had been a change in the users' behavior and which components from the behavior change models that the users experienced had made a difference. The results show, among other things, that approximately half of the users experienced a reduction in vegetable waste during the user test, and that the majority of the users experienced that the identified deficient behaviors were to some extent increased.
|
7 |
Motivation to donationSteneberg, Nellie, Ibarbachane, Sara January 2020 (has links)
Today, the world contains a large number of important non-profit organizations (NPOs) that seek to maintain the welfare of people and animals and to preserve the natural world. NPOs are extremely dependent on funds from the public which has resulted in severe competition between these organizations. This has also come as a result of the cut down of government support and a shortage of donations. Their lack of financial resources indicates that NPOs around the world face major challenges and are therefore in need of customized tools to increase their revenue and ensure their survival. With the purpose of increasing donations towards NPOs, this study aims to research how a media object can be developed and marketed in Bali to motivate tourists into donating money to the Bali Animal Welfare Association (BAWA) which is located in Canguu, Bali. By doing this, NPOs can use this research as tool for application within their own organization to increase their revenues.The media object that was chosen for this research was a poster, placed in the streets of Canggu, Bali and was selected because it has been shown that visual communication is a powerful tool for encouraging prosocial human behavior. The aim was to document how the media object affected levels of tourist engagement and ultimately their motivation to donate money to an NPO. A number of theories of motivation and behavior were used to form the foundation for this research. The methodology used included qualitative data collection by way of interviews, observations of local conditions pertinent to tourist interaction with media objects, as well as information gathered through a focus group involving local tourists. Research Through Design (RTD) was the framework that was used to structure the process for the creation and the testing of the prototype (the media object). The RTD included four phases, two of which were not completed due to complications involving the COVID-19 pandemic. The research concluded that the environment, attitudes towards legitimacy and emotional engagement all played a crucial role for the effectiveness and ultimately the success of a media object. Furthermore, it was concluded that there is a need for extended research on tourists’ behavior as well as consumer behavior, in relation to donors, in order to fully understand how a media object should be developed to motivate a tourist to donate money to an NPO.
|
8 |
Financial Modelling Using Fractional Processes And The Wiener Chaos Expansion / Undersökning Av Finasiella Modeller Med Fraktionella Processer Och Wiener's KaosexpansionHummelgren, Olof January 2022 (has links)
The aim of this thesis is to simulate stochastic models that are driven by a fractional Brownian motion process and to apply these methods to financial applications related to yield rate and asset price modelling. Several rough volatility processes are used to model the asset price and yield dynamics. Firstly fractional processes of Cox-Ingersoll-Ross, CEV and Vasicek types are introduced as models for volatility and yield data. In this framework it holds that the Hurst parameter that determines the covariance structure of the fBM process can be directly estimated from observed data series using a least squares log-periodogram approach. The remaining parameters in the model are estimated using a combination of Maximum Likelihood estimates and expectation estimations. In the modelling and pricing of assets one model that is studied is the fractional Heston model, that is used to model an asset price process using both observed asset and volatility data. Similarly two other similar rough volatility models are also studied, which are constructed so as to have log-Normal returns. These processes which in the thesis are called the exponential models 1 and 2 have rough volatility that are characterized by the CEV and Vasicek processes. Additionally the first order Wiener Chaos Expansion is implemented and explored in two ways. Firstly the Chaos Expansion is applied to a parametric fractional stochastic model which is used to generate a Wick product process, which is found to resemble the underlying process. It is also used to generate an approximate expansion of real yield rate data using a bootstrap sampling approach. / Den här uppsatsen syftar till att simulera stokastiska modeller som drivs av fraktionell Brownsk rörelse och att använda dessa modeller i finansiella tillämpningar relaterade till räntor och finansiella tillgångar. Flera volatilitetsprocesser som är rough används för att modellera ränte- och aktiedynamiken. Först introduceras de fraktionella varianterna av Cox-Ingersoll-Ross, CEV och Vasicek processer, vilka används för att modellera volatilitet och ränteprocesser. Med detta tillvägagångssätt gäller det att Hurstparametern, vilken bestämmer covariansstrukturen för den fraktionella Brownska rörelsen, kan uppskattas direkt från observerad data med en minsta kvadrat log-periodogram-metod. Samtliga andra parametrar i modellen uppskattas med en kombination av Maximum Likelihood och uppskattning av väntevärden. I modelleringen och prissättningen av finansiella tillgångar är en model som studeras den fraktionella Hestonmodellen, som används för att modellera en tillgång baserat på både volatilitets- och aktiedata. Ytterligare två liknande modeller studeras, vilka också har volatilitet som är rough och är konstruerade så att deras avkastning är log-Normal. Dessa processer, vilka i uppsatsen är benämnda som de exponentiella modellerna 1 och 2 har volatilitet som karaktäriseras av CEV- och Vasicekprocesser. Ytterligare är Wiener's Kaosexpansion av första ordningen också implementerad och undersöks från två håll. Först används den på en parameterbestämd fraktionell stokastisk modell, vilken används för att generera en Wickproduktprocess. Expansionen används även med hjälp av en bootstrap-metod för att generera en process från observerad data.
|
9 |
Wind energy analysis and change point analysis / Analyse de l'énergie éolienne et analyse des points de changementHaouas, Nabiha 28 February 2015 (has links)
L’énergie éolienne, l’une des énergies renouvelables les plus compétitives, est considérée comme une solution qui remédie aux inconvénients de l’énergie fossile. Pour une meilleure gestion et exploitation de cette énergie, des prévisions de sa production s’avèrent nécessaires. Les méthodes de prévisions utilisées dans la littérature permettent uniquement une prévision de la moyenne annuelle de cette production. Certains travaux récents proposent l’utilisation du Théorème Central Limite (TCL), sous des hypothèses non classiques, pour l’estimation de la production annuelle moyenne de l’énergie éolienne ainsi que sa variance pour une seule turbine. Nous proposons dans cette thèse une extension de ces travaux à un parc éolien par relaxation de l’hypothèse de stationnarité la vitesse du vent et la production d’énergie, en supposant que ces dernières sont saisonnières. Sous cette hypothèse la qualité de la prévision annuelle s’améliore considérablement. Nous proposons aussi de prévoir la production d’énergie éolienne au cours des quatre saisons de l’année. L’utilisation du modèle fractal, nous permet de trouver une division ”naturelle” de la série de la vitesse du vent afin d’affiner l’estimation de la production éolienne en détectant les points de ruptures. Dans les deux derniers chapitres, nous donnons des outils statistiques de la détection des points de ruptures et d’estimation des modèles fractals. / The wind energy, one of the most competitive renewable energies, is considered as a solution which remedies the inconveniences of the fossil energy. For a better management and an exploitation of this energy, forecasts of its production turn out to be necessary. The methods of forecasts used in the literature allow only a forecast of the annual mean of this production. Certain recent works propose the use of the Central Limit Theorem (CLT), under not classic hypotheses, for the estimation of the mean annual production of the wind energy as well as its variance for a single turbine. We propose in this thesis, an extension of these works in a wind farm by relaxation of the hypothesis of stationarity the wind speed and the power production, supposing that the latter are seasonal. Under this hypothesis the quality of the annual forecast improves considerably. We also suggest planning the wind power production during four seasons of the year. The use of the fractal model, allows us to find a "natural" division of the series of the wind speed to refine the estimation of the wind production by detecting abrupt change points. Statistical tools of the change points detection and the estimation of fractal models are presented in the last two chapters.
|
Page generated in 0.0268 seconds