• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 82
  • 73
  • Tagged with
  • 155
  • 155
  • 155
  • 155
  • 155
  • 28
  • 20
  • 19
  • 17
  • 14
  • 14
  • 14
  • 14
  • 7
  • 6
  • 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.
51

Vad säger neurobiologisk forskning om motivationens betydelse för inlärning?

Forngren, Sofia January 2018 (has links)
Kan motivation till att lära sig gå att se genom avbildningar av hjärnan? Finns det någraneurobiologiska stöd för att det dessutom skulle kunna påverka minnesbildning? Tidigareforskning har visat att aktivering av belöningssystemet och ökade nivåer av signalsubstansendopamin kan gynna minnesbildning. I denna översiktsartikel behandlas studier som berörmotivation ur olika psykologiska aspekter och hur det påverkar det deklarativalångtidsminnet. Olika hjärnavbildningsmetoder där dopaminerga regioner och hippocampushar varit centrala, tillsammans med olika inlärningsuppgifter och psykologiska tester talar föratt motivation är en viktig faktor för inlärning. Dessutom visar flera av studierna att positivåterkoppling har en bättre effekt på inlärning jämfört med negativ återkoppling.
52

Mossfloran vid vattenkvarnar i sydöstra Sverige

Lundén, Eric January 2019 (has links)
Bryophytes play an important role in ecosystems in running waters and are common growing on structures in and around watermills. These watermill habitats differ from other parts of the watercourse in terms of microclimate and disturbance regime, and in providing more suitable and variable substrates. Bryophytes were sampled in and around five watermills and five reference sites 300 meters up or downstream from the watermill in the province Småland, in south-eastern Sweden. Species richness was compared between the sites and differences in community structure were analysed by a Discriminant Analysis. In 90% of the cases, the species composition was found to be specific for watermills and reference sites, and the mean species number was 57% higher at watermills than at the reference sites. Rocks and boulders in a wide range of sizes, concrete and mortar structures with pH-levels higher than that of the underlying bedrock, and stronger currents were identified as some of the causes of the higher diversity at the watermills. Restauration projects in rivers, including dam removal, constitute a potential threat to the bryophyte flora of watermills since the structures they grow on may either be removed or destroyed. Changes in microclimate and disturbance regime are other potential threats to species in these habitats. / Mossor spelar en viktig roll i ekosystem i rinnande vatten och är vanligt förekommande på strukturer i och vid vattenkvarnar. Dessa habitat skiljer sig från vattendraget i övrigt bland annat genom annorlunda mikroklimat och störningsregim, men också genom en hög mångfald av för mossor lämpliga substrat. I denna studie undersöktes mossfloran vid fem vattenkvarnar och fem referensområden. Artantal jämfördes mellan kvarn- och referensområden och skillnader i artsammansättning analyserades med en diskriminantanalys. I 90% av fallen var artsammansättning specifik för respektive habitat och medeltalet för antalet arter var 57% högre vid vattenkvarnar jämfört med referensområden. Stenar och block i olika storlekar, betong och murbruk med högre pH-värden än den underliggande berggrunden och starkare strömmar är några av de faktorer som bidrog till den ökade artmångfalden vid vattenkvarnarna. Restaureringsprojekt i rinnande vatten, till exempel dammutrivningar, utgör ett potentiellt hot mot mossfloran vid vattenkvarnar eftersom de strukturer mossorna växer på riskerar att antingen förstöras eller tas bort. Förändringar i mikroklimat och störningsregim är två andra potentiella hot mot arter i dessa miljöer.
53

The Co-Strategy Process: introducing technology through interdisciplinary collaboration, so it meets biology in society : A case study regarding the path of Robot-Assisted-Rehabilitation from laboratory to patients in Sweden

Suciu, Pascalina January 2019 (has links)
As part of the current fast growing development of digital technologies, collaborations between professions such as neurosciences, robotics, big data processing and artificial intelligence offer new possibilities for healthcare. For these new technologies to reach clinical practice, there is an increasing need for interdisciplinary organizational work to support decision-making over their introduction. In the field of neurorehabilitation, exoskeletons are an example of a robotic tool that can be used to regain locomotion abilities after a neurological injury. They are part of an umbrella term, Robot-Assisted-Rehabilitation (RAR), that stands for neurological recovery techniques assisted with robotic tools. For these tools, the introduction, evaluation and implementation in clinical practice have not been evaluated. In many cases it is also not taken into account that tools such as rehabilitation robotics are context-dependent. In other words, the needs, opportunities and challenges that come together with working efficiently with this new technology can widely vary between clinics, regions and countries. Lastly, it appears that smaller hospitals consider themselves in need of tools to support their decision-making in the RAR introduction phase. In collaboration with Hälsostaden and Region Skåne, we set out to develop a tool to support Ängelholm Hospital (ÄH) in their decision-making over a test-bed trial of RAR in their clinical setting. A tool that we coined the Co-Strategy Process (CSP), was developed based on identified needs related to this stage of the process, using a blend of interdisciplinary scientific methods. It integrates internal and external interdisciplinary expertise and includes four steps: Preparation, Knowledge Empowerment, Exchange & Development and Synthesis & Report. The current Master thesis presents the development and assessment of the CSP at ÄH. In the present context, it results in a new tool for supporting organizations implementing new technologies, optimized based on its application in a Swedish clinical setting. This tool aims at serving this introductory process, so that new technologies can be implemented meeting the needs of both the clinic and patients. / e Rehab-robotic project in collaboration with Uppsala University, Basel University and ETH Zurich
54

The Molecular Diversity and Biogeography of Tardigrades

Schuman, Irina January 2017 (has links)
Tardigrades can handle extreme conditions such as heat, cold and drought, thanks to a process called cryptobiosis which can be found in a limited amount of taxa on Earth. More knowledge about such animals may help us to understand the potential and limitations of life both on Earth and possibly in space. Such knowledge may also help develop novel, useful applications for the society, such as better storage of sensitive medicine. However, our knowledge about tardigrades is limited. We know little about their distribution and diversity, especially in Sweden, and above all in northern Sweden. The aim of this study was threefold; i) to explore the biogeography of the tardigrades based on molecular data; ii) to screen for tardigrades in Umeå by examining moss samples from different locations; and iii) to explore some of the associates of tardigrades in moss (such as bacteria and micro- and meiofauna). The biogeography was explored by collecting all published ribosomal gene sequences (the small subunit 18S rRNA) from the Silva gene database. These sequences were used for plotting the locations from which these gene sequences had been retrieved on a world map and the correlation between gene sequence, country and biotope was examined. The tardigrade groups most sequenced are Macrobiotus, Ramazottius and Echiniscus, and the milieu most studied seems to be different types of soil. Other investigated isolation sources are drinking water, cryconite and church walls. However, much remains to be further explored. For example, the world map showed that the only molecular data on Swedish tardigrades have been retrieved from Öland. In the lab, tardigrades were found in some of the moss samples, together with other micro- and meiofauna. Three groups of bacteria (Betaproteobacteria, Gammaproteobacteria and Firmicutes) could be identified in one of the investigated mosses. These results suggest that tardigrades live in a diverse environment with different types of organisms both on the microbial as well as on the micro-meio-fauna level.
55

Exercise-induced adult hippocampal neurogenesis and the effect of exercise and adult hippocampal neurogenesis on spatial learning and memory

Sturesson, André January 2018 (has links)
It was long believed within the scientific community that the adult brain was unable to generate new neurons. In the end of the 1990s the consensus changed and it is since believed that the adult brain can and does generate new neurons after birth, a process referred to as adult neurogenesis. Adult neurogenesis takes place in two places in the adult brain: the subventricular zone (SVZ) in close proximity to the olfactory bulb and the subgranular zone (SGZ) in the hippocampus. The level of adult hippocampal neurogenesis (AHN) can be upregulated and one part of the aim was to examine the effect of voluntary chronic aerobic exercise (VCAE) on AHN. It is clear that voluntary chronic aerobic exercise reliably increases AHN. Still, the function of these new brain cells is under debate. Spatial learning and memory are among the main abilities that have been focused on. The other part of the aim was to examine the effect of VCAE and AHN on spatial learning and memory. The reviewed literature suggests that both AHN and spatial learning and memory increase together from VCAE, although it does not show causation, that an increase of AHN from VCAE causally effects spatial learning and memory. More studies are needed to investigate if a causal relationship exists.
56

Emotion regulation and its influence on decision making : Emotion regulation and decision making

Skenderija, Tea January 2018 (has links)
One thing that may affect our decision making is emotions, and emotions are something we can regulate, this is referred to as emotion regulation. the use of emotion regulation strategies influence our decision making how this process out at the neural level The findings within this will suggest that the emotion regulation strategy reappraisal, compared to suppression, our decision making At the neural level, findings within this will indicate that neural changes may occur when individuals regulate their emotions in relation to making decisions. For instance, decreased activity within the striatum was associated with making less risky decisions when using the emotion regulation strategy reappraisal. On the other hand, the ventromedial prefrontal cortex may be important in mediating the neural systems of emotional states and working memory in order to enable decision making. This will also cover some prominent theories of emotion and decision making. Emotion regulation, as well as strategies for emotion regulation, will be explained.
57

Skip-a-day feeding does not cause difference in liver lipid content in broiler breeders

Sander, Elin January 2017 (has links)
There has long been evidence for increased lipids in the liver of chickens exposed to feed restriction, commonly used for production hens. Lipogenesis is an important part of the metabolism and storing of glucose, a source of energy. Few studies compare the difference of lipids in the liver in chickens between regular feed restriction and skip-a-day diets, despite differences in lipid content found in other organs and in overall carcass. In this study I experimentally investigate if a difference in lipid content can be found in broiler breeders exposed to two different feeding regimes, 65 % feed restriction and 5:2 skip-a-day, along with the difference between days and time points (a.m. and p.m.). I also experimentally investigate the effect on dry weights of the liver. I expected to see a difference in lipids of the liver, with an increase found in skip-a-day birds. However, a difference could only be observed in the dry weights of the livers in birds exposed to skip-a-day feeding. Although there was no significant change in lipids, there is a pattern for increase in lipids in skip-a-day birds. Therefore, the conclusion can be drawn that an increase in lipogenesis caused by skip-a-day diet exists but it was not big enough to cause a significant difference in lipid content. For the dry weights of the livers, we can suspect lipids and glycogen as the reason for the increased weight but to determine exactly how these two components affect the skip-a-day birds’ further inquiry is needed.
58

Effects of effluent wastewater in developing zebrafish (Danio rerio)

Frieberg, Kim January 2018 (has links)
Traditional wastewater treatment is known not to be specifically designed to eliminate the new generation of chemical residues that ends up in the sewage system. Polluted wastewatereffluent therefore reaches the aquatic environment possibly causing adverse effects in aquatic wildlife. The effects of effluent water from five Swedish sewage treatment plants sampled on 6 occasions 2017, were studied in developing zebrafish (Danio rerio). The study included morphological, physiological and behavioural endpoints. Overall there were few effectswhere deviations from control animals could be seen in the exposed zebrafish. The overall outcome of this assessment was that the wastewater effluent had no consistent effects on the early development of zebrafish. The consequences of continuous low-level exposure duringthe whole life-cycle of wild fish are presently unknown and further studies are needed to evaluate potential risks.
59

Hitting the mark : studies of alterations in behaviour and fertility in ethinyl estradiol-exposed zebrafish and search related biomarkers

Caspillo, Nasim Reyhanian January 2016 (has links)
In this thesis, we have analysed the effects of EE2 on non-reproductive behaviours and fertility. We have showed that two doses of EE2 in male adult short-term exposures evokes opposite behaviours in the novel tank test. A lower dose induced increased bottom-dwelling, a sign of increased anxiety and a higher dose increased surface-dwelling, which would likely expose themselves to predation in a natural environment. Increased shoaling was observed in both exposures, possibly affecting feeding and reproduction opportunities. Fertility analysis of these fish demonstrated a complete inhibition of spawning in the highest dose group. To investigate mechanisms behind the spawning failure, we examined expression levels of genes involved in zebrafish sex differentiation and maintenance of gonadal function. We found downregulated transcription levels of male-predominant genes, suggesting a demasculinization of the testes contributing to functional sterility in these fish. We have demonstrated that non-reproductive behaviour in zebrafish is highly sensitive to EE2 exposure during development. After exposing male and female zebrafish to low doses of EE2 followed by remediation in clean water until adulthood, the fish displayed increased anxiety and shoaling behaviour, demonstrating persistent effects of EE2. Furthermore, behavioural effects were transferred to their progeny. Decreased fertilisation success of the developmentally exposed fish was observed in both sexes when mated to untreated animals of the opposite sex. These fertility effects persisted although the fish had a long remediation period, implying likely reduced fitness of fish populations in aquatic environments. Based on our findings on non-reproductive behaviours and fertility, we performed RNAsequencing analysis of the brain and testes in order to investigate possible biological mechanisms behind the persistent effects. There is a need for biomarkers allowing detection of both reversible and irreversible effects in animals exposed to estrogenic substances, hopefully contributing to better risk assessments for EDCs. Results from RNA-sequencing would serve as a basis for continued studies in pursuit of potential biomarkers.
60

Socioscientific argumentation : Aspects of content and structure

Christenson, Nina January 2015 (has links)
Socioscientific argumentation has shown to be a feasible educational framework for promoting citizenship and for cultivating scientific literacy. However, there are several aspects of this educational framework that have been shown to be problematic. Consequently, in this thesis I investigated various aspects of quality of socioscientific argumentation from both an upper secondary student and a teacher perspective. By using students’ written argumentation on socioscientific issues (SSI) I studied how they justified their claims. The results showed that different SSI led students to use different subject areas in their justifications. I also compared science majors with social science majors and found that the number of justifications provided by the students is related to their discipline background. In these two studies, a new content focused analytical framework for analyzing content aspects of socioscientific argumentation, the SEE-SEP model, was used and shown to be suitable for this purpose. However, to ensure that students are able to produce high-quality arguments I suggest that both content and structural aspects need to be considered. As a result of this, I have presented a framework based on research literature and the Swedish curriculum, for analyzing and assessing both these aspects of socioscientific argumentation. Moreover, I investigated how science and language teachers assess students’ socioscientific argumentation and found that the science teachers focused on students’ ability to reproduce content knowledge, whereas language teachers focused on students’ ability to use content knowledge from references, and the structural and linguistic aspects of argumentation.   The complexity of teaching socioscientific argumentation makes it difficult to teach and assess comprehensively. In order to promote quality and include both content and structural aspects, I suggest that a co-operation among teachers of different disciplines is beneficial. / Socioscientific argumentation has shown to be a feasible educational framework for promoting citizenship and scientific literacy. In this thesis I investigated various aspects of quality of students socioscientific argumentation and how teachers assess this. The results showed that different SSI led students to use different subject areas in their justifications and that the number of justifications provided by the students is related to their discipline background. Moreover, to promote students high-quality arguments I have presented a framework for analyzing and assessing both content and structural aspects. I also investigated how science and language teachers assess students’ socioscientific argumentation and found that the science teachers focused on students’ ability to reproduce content knowledge, whereas language teachers focused on students’ ability to use content knowledge from references, and the structural and linguistic aspects of argumentation. The complexity of teaching socioscientific argumentation makes it difficult to teach and assess comprehensively. In order to promote quality and include both content and structural aspects, I suggest that a co-operation among teachers of different disciplines is beneficial. / <p>Article IV was in manuscript form at the time of the thesis defense and has been published afterwards.</p>

Page generated in 0.1332 seconds