• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 184
  • 116
  • Tagged with
  • 300
  • 257
  • 202
  • 199
  • 197
  • 197
  • 197
  • 75
  • 73
  • 59
  • 59
  • 56
  • 54
  • 45
  • 44
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Accumulation of poly- and perfluoroalkylated substances (PFASs) and mercury in fish tissue from Lake Tana, Ethiopia : Evaluation of human exposure due to increased fish consumption

Sjöholm, Margareta January 2015 (has links)
Both poly- and perfluoroalkylated substances (PFASs) and mercury (Hg) are persistent bioaccumulative, and toxic substances (PBTs) of great concern due to their health effects on humans.  These pollutants are ubiquitously occurring in the global aquatic environment and dietary intake of fish is the major exposure pathway for humans. PFASs and Hg are widely studied in the temperate zones, but little is known from the tropical aquatic systems in Africa. Lake Tana, Ethiopia, is of high ecological value and predicted to increase its fish production and export during following years, but knowledge of human health effects due to bioaccumulated pollutants loading from this lake is lacking. The objective of this study was therefore to compare Hg and PFAS concentrations between sites and species, evaluate accumulation patterns and assess the human health risk with increased fish consumption.    During October 2014, a total of 97 fish specimens from five species (Labeobarbus megastoma, Labeobarbus gorguari, Labeobarbus intermedius, Oreochromis niloticus and Clarias gariepinus) were collected from seven sites in Lake Tana. The fish was dissected in Bahir Dar, where a muscle sample was taken from the dorsal line, and later analyzed at the Swedish University of Agricultural Sciences. To determine differences and correlations between sites and species as well as for Hg and PFASs, statistical analyses were conducted and to determine the health risks in increased fish consumption a hazard ratio (HR) was calculated for both substances.   The results showed several similarities between Hg and PFASs, including higher concentrations in piscivorous fish species (L. megastoma and L. gorguari) than non-piscivorous and also spatial distribution similarities. Hg concentrations ranged from 0-639 ng g-1 wet weight (ww) with an overall mean of 137 ng g-1 ww for all species. Seven PFASs were detected (PFNA, PFDA, PFUnDA, PFDoDA, PFTeDA, PFBS, PFOS), and the ∑PFSA concentrations ranged from non-detected to 3.61 ng g-1 ww. PFDA was found in all sites and species, compared to PFOS, which only was found in piscivorous species in elevated levels. The positive correlation between Hg and PFOS imply that these substances have similar accumulation patterns. The HRs showed that increased fish consumption is harmless to the Ethiopian population regarding PFAS and Hg contamination. Varied fish consumption is of importance though since several individuals from the piscivorous species contained Hg concentrations exceeding the WHO marketing limit of 0.5 μg g-1 (500 ng g-1). / Både poly- och perfluoralkylerade ämnen (PFASer) och kvicksilver (Hg) är persistenta, bioackumulerande och toxiska (PBT) ämnen som kan utgöra stor hälsorisk för människor. PFASer och Hg förekommer globalt i den akvatiska miljön och den mest betydande källan för mänsklig exponering av dessa ämnen är fiskkonsumtion. Studier av PFASer och Hg är vanligt förekommande i de tempererade zonerna, men väldigt lite är känt från de tropiska akvatiska systemen i Afrika. Lake Tana, Etiopiens största sjö, har stort ekologiskt värde och fiskproduktion och export från sjön förutspås öka under kommande år. Däremot saknas kunskap om hur denna föroreningsbelastning med ökat fiskintag kommer påverka befolkningen i landet. Syftet med denna studie var därför att jämföra Hg- och PFAS-koncentrationer mellan områden och arter, utvärdera ackumuleringsmönster och bedöma hälsoriskerna med ökad fiskkonsumtion i landet.   Under oktober 2014 samlades totalt 97 individer in från fem arter (Labeobarbus megastoma, Labeobarbus gorguari, Labeobarbus intermedius, Oreochromis niloticus och Clarias gariepinus) och från sju olika platser i Lake Tana. Dissektionen utfördes i Bahir Dar (där muskelprover togs från dorsala rygglinjen) och sedan fördes proverna till Sveriges lantbruksuniversitet (SLU) för analys. För att bestämma skillnader och korrelationer mellan områden och arter, samt mellan Hg och olika PFASer, utfördes statistiska analyser och för att utvärdera hälsorisken av en ökad fiskkonsumtion beräknades riskfaktorer för båda ämnena.    Resultaten påvisade flertalet likheter mellan Hg och PFASer, bland annat högre koncentrationer i piskivora fiskarter (L. megastoma and L. gorguari) än icke-piskivora och även likheter i koncentrationer mellan provområdena. Hg-koncentrationerna varierade mellan 0-639 ng g-1 våtvikt (vv), med ett medel på 137 ng g-1 vv för alla arter. Sju PFASer detekterades i analysen (PFNA, PFDA, PFUnDA, PFDoDA, PFTeDA, PFBS, PFOS), där ∑PFSA koncentrationerna varierade mellan icke-detekterbara till 3,6 ng g-1 vv. PFDA förekom i alla arter och områden, medan PFOS bara fanns i förhöjda värden i piskivora arter. Den funna positiva korrelationen mellan PFOS och Hg antyder att dessa ämnen har liknande ackumulationsmönster. De beräknade riskfaktorerna visade att en fiskkonsumtions-ökning inte skulle utgöra en risk för den etiopiska befolkningen med avseende på Hg- och PFAS-halter. En varierad fiskkonsumtion är dock av stor vikt eftersom flertalet individer från de piskivora arterna innehöll högre Hg-koncentrationer än den av WHO rekommenderade gränsen på 0,5 μg g-1 vv.
102

En skitig historia : - En studie kring varför samhällen slutar använda mänsklig avföring som gödsel vid matodling. / A crappy history : - A study focusing on why humans stop using human excrement as a fertilizer when producing food.

Thimrén, Tove January 2018 (has links)
Fosfor är ett nödvändigt näringsämne inom jordbruket, trots detta är vi på väg att använda upp den fosfor vi har tillgång till i marken. Denna studie har därför valt att fokusera på en stor källa till fosfor som inte tas till vara på i många av dagens samhällen: mänsklig avföring. Många samhällen har genom historien använt mänsklig avföring som en resurs, bland annat som gödsel vid matodling, vilket återför en stor del av fosforn till marken. I dagens samhällen ses mänsklig avföring som någonting oönskat och äckligt. Vad är det som skapat denna ovilja att använda denna källa till fosfor? Varför slutade samhällen använda mänsklig avföring som gödsel vid matodling? Syftet med denna studie är att belysa de anledningar som ligger bakom att människor slutar att använda mänsklig avföring vid odling av mat. En tematisk analys, och utvalda delar av en komparativ analys, har använts för att analysera lämpligt publicerat material. Denna analys har skapat resultatet som sedan har ställts mot studiens teoretiska ramverk vilket inkluderar: människans syn på sin egen avföring, smuts och renhet, och mänsklig avföring som resurs. Studiens resultat tyder på att det främst är en accelererad urbanisering och en modernisering av samhället som leder till att människor slutar att använda mänsklig avföring som gödsel inom matodling. Människans syn på renhet ställs mot synen av mänsklig avföring som en resurs. Valet att använda mänsklig avföring eller ej styrs av den kulturella uppfattningen om vad som är rent och smutsigt. När de negativa associationerna kring mänsklig avföring överväger de positiva så leder det till att människor tar avstånd från mänsklig avföring trots att exkrementer fortfarande skulle kunna användas som en resurs. / Phosphorus is an essential nutrient in agriculture, despite this fact we are well on our way to using up the phosphorus we have access to in the ground. This study has therefore focused on a major source of phosphorus that is not taken into consideration in a vast majority of today’s societies: human excrement. Many countries have used human excreta as a resource throughout history, including as a fertilizer when producing food, which ensured that a major part of the phosphorus was returned to the soil. In societies today human excrement is viewed as something unwanted and disgusting. What is it that makes humans hesitant to use this source of phosphorus? Why did societies stop using human excrement as a fertilizer when growing food? The purpose of this study is to examine the underlying causes for why people stop using human excrement as a fertilizer when producing food. A thematic analysis, combined with selected parts of a comparative analysis, has been used to analyze apt publicized material. This analysis has resulted in the study’s result, which has then been pitted against the theoretical framework for this study. The theoretical framework includes: people’s view of their own excreta, dirt and cleanliness, and human excreta as a resource. The result suggests that it primarily is an increased urbanization and a modernization of society that leads people to stop using human excrement as a fertilizer when producing food. Human perception of purity is pitched against the view of human excrement as a resource. The choice of using human excrement or not is governed by the cultural perception of what is clean and what is dirty. When the negative associations connected to human excrement outweigh the positive, then humans distance themselves from it, even though the excrement could still be used as a resource.
103

An educational programming environment for the Swedish school

Lisa, Lundgren January 2018 (has links)
Programming is currently being introduced as an obligatory part of the K-9 education in Sweden with the aim to strengthen pupils’ digital competence and prepare them with skills adapt for the 21st century. The challenge is now to successfully integrate programming as a tool for teaching and learning within existing practices. Teachers are expected to support their pupils learning about programming despite their own limited chance to acquire knowledge on the subject. The Swedish National Agency for Education (Skolverket)has given some guidance but research on this area is rather limited and a lot is left to the teachers to decide and educate themselves in. Educational programming environments (EPEs), especially aimed at novices, can support teachers in this integration but needs to be suitable for the objectives from the Swedish school to not unintentionally direct the way teaching is done. This study aims to answer how an EPE should be designed to fit within the Swedish school context with a focus on the teachers’ perspective. To study this, seven interviews were conducted with educators in middle school with experience of working with programming in the classroom, followed by two observations during lectures with EPEs. The results provided implications that were used to form design guidelines for an EPE aimed at the Swedish school.
104

Revealing the secret pieces of the puzzle : Studying the hidden influences of agile development context on user-centered design

Laanpere, Jaak January 2018 (has links)
In a world dominated by digital technologies, user-centered design aims to ensure that the users are catered with solutions that deal with their needs. As agile methods have become a prevalent approach in software development, it is crucial for the two disciplines to work together. However, existing studies have already presented incompatibilities between the methods of the two disciplines. This study intends to investigate the impact that agile principles have on the adoption of user-centered approach on a broader scale through the many parties involved in the process. By conducting interviews with practitioners and interpreting the results through the lens of Engeström’s activity system model, the findings of the study reveal significant influences imposed on the user-centered approach by external and organizational factors that are intensified by the agile principles. Three main areas of concern are identified and accompanied by broad suggestions on how to approach resolving them, focusing on the empowerment of UX designers, accurate deliberation of the intentions and practices of user-centered approach, and close collaboration to raise awareness of the benefits of user-centered approach. Lastly, it is emphasized that the identified areas of concern – primarily the problematic impact from clients and executives – need further extensive research to provide definitive solutions.
105

SitLight : a Wearable Intervention for Improving Sitting Behavior

Soltani Nejad, Farideh January 2018 (has links)
Various studies have taken different approaches to persuade users into adopting a healthy sitting posture. In addition to the sedentary lifestyles we have come to adopt, the importance and reasoning of these studies stem from the adverse effects of poor posture on our health and mood. However, studies approaching this area with real-time visual modality integrated into clothing are rather sparse. Utilizing this integration might potentially fulfill the requirements of the ubiquitous computing era and inform the users in a calmer way. To evaluate various aspects of this concept, a mid-fidelity prototype was developed and tested with users. Semi-structured interviews were then conducted to obtain their thoughts and opinions on such an approach. In addition to the approval of the concept, further concerns, advantages and disadvantages were disclosed, and used to inform a design space for similar concepts. Although requiring more research, the results of this study outline a primary design space consisting of essential characteristics one needs to be aware of when designing a similar concept.
106

Understanding of bold social media content : A study of dick-pics as a way to communicate

Karlsson, Amanda January 2018 (has links)
Today it is just as important to understand the content on social media platforms as the technology that are being used. With the help of technology the content does not need to be just words but can also be anything from videos to simple symbols. Taboo subjects like dick-pics are often swept under the rug as being too offensive to talk about. But if technology is to keep up with the content even the sensitive subjects need to be understood. Since anyone can send anything to anyone it is important to show how different people react. If the sender of a dick-pic thinks it is amusing, it is important to tell how the receiver may react. It can be a self-representation to send a dick-pic, just to show a new or a hidden side of oneself. It can also be a way to exercise power over another person as well as harassing the receiver with a sexual picture. But a dick-pic could also be just a joke sent to someone and a way of communicating with friends. This is a quantitative research with 120 participants answering a questionnaire which focused on sending and receiving dick-pics and the reason and reaction of sending dick-pics online. The study showed three main reasons for sending dick-pics and the reasons were categorised as following: language online, self-representation and power structures.
107

Skola och privatliv - två skilda världar? : En kvalitativ studie om fem grundskoleelevers medievanor och bildundervisningens multimodalitet. / School and personal life – two different worlds?

Mases Calson, Louise January 2017 (has links)
I denna uppsats har fem grundskoleelever i årskurs 3-6 intervjuats om deras uppfattningar av bildundervisningens relevans i relation till deras erfarenheter av visuell kultur. Gemensamt för eleverna var att de på olika vis använde sig av sociala forum och var vana mediala orienterare. Bildämnet har under tid förändrats och läroplanen ställer nu även krav på multimodal undervisning med digitala verktyg. Resultatet avslöjar dock att undervisningen inte motsvarat samhällets utveckling vilket lämnat eleverna att önska en mer digitaliserad undervisning. Insamlandet av empiri har skett genom kvalitativa intervjuer där jag löpande fört anteckningar för hand och därefter bearbetat materialet genom ett digitalt skrivprogram. Empirin har analyserats utifrån det multimodala perspektivet, ett relativt nytt perspektiv vilket bygger på kommunikation genom olika teckensystem och medier.
108

VEMS SÄKERHET? VILKA RÄTTIGHETER? : Om diskursförändringen i svensk migrationspolitisk riksdagsdebatt 1975-2002

Olmsäter, Therese January 2007 (has links)
Human rights and solidarity, as well as moral and legal responsibilities to protect people in need of refuge, seem to be principles of secondary importance within international migratory policies today. Instead, the predominant view seems to focus more and more on the protection of territorial borders, the welfare state and national identity. This international change in discourse can also be seen in the political trends of individual states. There are reasons to believe that this is a development that is also perceptible in the political rhetoric that is used in parliamentary debates, which constitute the main focus of this thesis. The aim of this study has therefore been to increase the understanding of this change in migratory policies by analyzing Swedish parliamentary debates between 1975 and 2002, using a theoretical framework focused on two different perspectives on security: First, the Copenhagen School and securitization of migration, and second, human security and human rights. The method consists of an interpretative and reflective method, together with a critical discourse analysis approach. The main results of the thesis show a possibility to distinguish four sets of discourses with close ties to the contemporary societal context during this period of almost three decades. However, the main arguments for such a change in discourse are first, that although the migration policies have developed in a more restrictive way since the 1980’s, the arguments and rhetoric in parliamentary debates have not changed much even though the tendencies are harder tones simultaneously with such restrictions. Second, in spite of this similarity, there have been people in parliament who have raised their voices and protested during this period when, in their view, the politics has moved outside of the ordinary framework. Finally, this thesis argues that it is possible to place the two debating sides in what could be named the security/rights- nexus, depending on each side’s point of departure according to the security framework of this thesis.
109

Principles of workflow support in life critical situations / Principer för arbetsflödesstöd i livskritiska situationer

Lundberg, Jenny January 2007 (has links)
The prime objective is to investigate how technology and work organization can support the workflow in handling time critical emergency calls, having the prerequisites of giving the highest priority to saving human lives and minimizing the effects of emergency situations. The challenge is to maintain and improve the quality of service (QoS) during and after a proposed technology driven organizational change. This thesis is based on empirical work including extensive ethnographical studies of emergency call handling at Swedish Emergency Service Centres, SOS centres. Today the SOS centres are basically organized as independent centres. The proposed technology enabled organization concerns the contingency of handling emergency calls nationwide, in SOS clusters. One of the desired outcomes of this reorganization is that peaks and falls in the handling of emergency calls will be levelled out. It is assumed that any operator will be able to handle the call independent of the location of the emergency situation, opening up for a more efficient handling of incoming calls. In principle, introducing new information technologies enables this reorganization of SOS centres. However, the basic claim of our investigation is that a transition to the new organization has to take into account systemic requirements, to support a non-disruptive change. The first of the three main results concerns essential aspects of technology based organizational changes. From the empirical work, we have concluded that the tasks constituting the workflows at SOS centers are conducted in parallel, and that the coordination of the tasks can be modeled using a risk-driven blackboard-based spiral model. We have also concluded that there is a rich face-to-face communication and body language situation within the centers supporting coordination of workflows. This coordination is context-dependent thus the means of creating awareness of the overall situation in the centre support the acquisition of important extra information in the specific case. The second result concerns methods and models to increase the quality of the requirement specification process. The principal approach is to specify assessments and systemic requirements. Furthermore, issues such as how to validate empirically based workflow models, as well as how to measure groupware usability and how to support the information sensitive change are considered. Suggestions concerning methods and models that could provide means to that end are presented. The third result concerns identification of relevant research and development challenges coupled with new insights about combining ethnographical approaches with system modeling. Identification and suggestion of suitable experimental platform design, enabling testing of service qualities, including a suggested role for agent technologies are presented. / Utmaningen är att säkerställa och förbättra kvalitén i hanteringen av nödsamtal vid en eventuell förändring från enskilda SOS centraler till SOS cluster.
110

Developer Experience of a Low-Code Platform: An exploratory study

Dahlberg, Daniel January 2020 (has links)
In recent years, low-code development has become increasingly popular, enabling developers to write less code and focus on the objective. However, while proven efficient, little attention has been given to how developers experience working in these development environments. This is significant as providing unpleasant experiences could reduce the benefits of low-code platforms by leaving the developers unhappy. As such, this study aims to gain an understanding of developer experience in low-code environments. The study was conducted with an IT-company recently specialized in low-code solutions, where participants were chosen based on having prior experience with low-code development. This ensued in interviews with six low-code developers as well as a project leader. Main positive experiences found were, feeling more productive, improved customer relations, focus on the objective, shared developer understanding, and quick learnability. Key negative experiences found were, having work constrained, limited freedom and creativity, inadequate documentation, and overview, and having poor and unsafe teamwork capabilities. To the best of my knowledge this is the first study to explore developer experience in low-code development environments and stands as groundwork for future studies in low-code developer experience.

Page generated in 0.0449 seconds