Toxicity of methylmercury

Metylkvicksilver (MeHg) är en form av tungmetallen kvicksilver och det är den form som är farligast för djur och människor. Det beror på dess organiska egenskaper som gör att det biomagnifieras genom födokedjan, effektivt absorberas från föda, distribueras till många organ, koncentreras i levande organismer, passerar blod-hjärnbarriären och ackumuleras, samt orsakar skador även vid låga doser. Det har neurotoxiska och immunologiska effekter på djur i alla åldrar, men djur i prenatalperioden är känsligast för exponering av MeHg och kan drabbas av utvecklingsstörningar. Effekterna skiljer sig något mellan hanar och honor, men är även individuella. Dessutom skiljer sig tidpunkter för utveckling hos olika djur och organ är olika känsliga. De viktigaste verkningsmekanismerna bakom toxiciteten är metylkvicksilvers inducering av oxidativ stress och en indirekt excitotoxicitet. Det är genom att förstå verkningsmekanismerna som forskning på eventuella behandlingar vid metylkvicksilver-förgiftning kan tas fram. Försök till behandling har gjorts med olika ämnen som är viktiga för utveckling av hjärnan, samt med olika kelerande ämnen och selen. Exponering för metylkvicksilver sker främst genom intag av fisk eller andra akvatiska arter, men kan drabba prenatala djur genom att MeHg passerar från modern över till fostret via placenta. Fisk får i sig ämnet efter att oorganiskt kvicksilver metylerats i akvatiska sediment och tagits upp av krill och plankton, som sedan intas av fiskarna. Det elementära kvicksilvret kommer från naturliga processer eller från utsläpp orsakade av människan och det kan finnas kvar länge i naturen samt färdas långt, vilket gör det till ett globalt problem som det behövs mer forskning kring vad gäller alla former av tungmetallen. Det finns redan många studier gjorda på metylkvicksilvers akuta effekter, men fler som utforskar de kroniska effekterna behövs. Syftet med den här studien är att sammanfatta de toxiska effekter MeHg har, vilka verknings-mekanismer som ligger bakom dem och eventuella behandlingar som skulle kunna användas vid MeHg-förgiftning. Det görs även en granskning av de skillnader och likheter som finns mellan djur och människa som exponerats för MeHg, vilket visar att olikheterna inte är särskilt stora och djurstudier därför skulle kunna vara bra som grund för riskbedömning hos människa.Methylmercury (MeHg) is for animals and humans the most dangerous of all the forms of the heavy metal mercury. That is because it has organic properties and biomagnifies through the food chain, is efficiently absorbed from food, is distributed to many organs, concentrates in living organisms, crosses the blood brain barrier, and accumulates and causes damage even at low doses. It causes neurotoxic and immunological effects in animals of all ages, but animals in the prenatal period are the most sensitive to exposure of MeHg and may suffer from MeHg-induced developmental disabilities. The effects differ somewhat between males and females, but they are also individual. In addition, time points for the development of various animals and sensitivity of organs differ. The main mechanisms of action behind the toxicity is the induction of oxidative stress and an indirect excitotoxicity. It is by understanding the mechanisms that research on possible treatments of methylmercury poisoning can be done. Attempts at treatment have been made with various agents that are important for brain development, and with different chelating agents and selenium. Exposure primarily occurs through ingestion of fish or other aquatic species, but MeHg can cross over from the mother to the fetus through the placenta and therefore also has an effect on prenatal animals. Fish get exposed after the methylation of inorganic mercury to methylmercury in aquatic sediments and ingestion of krill and plankton exposed to the converted methylmercury. The inorganic mercury derives from natural processes or from emissions caused by humans, and its long-lasting abilities in the atmosphere together with the capacity to travel long distances make it a global matter that needs to be more researched regarding all forms of the heavy metal. There are already many studies made on the acute effects of methylmercury, but more studies on the chronic effects is needed. The purpose of this study is to summarize the toxic effects of MeHg, the mechanisms of action behind them and possible treatments that could be used in MeHg poisoning. Also, an examination of the differences and similarities between animals and humans exposed to MeHg is made, which shows that the differences are not very large and that animal studies therefore could be useful as a basis for risk assessment in man

Füsioteraapia eriala praktika juhendajate rahulolu üliõpilaste ettevalmistusega õppepraktikaks

http://www.ester.ee/record=b4436762~S

Biogasinvesteringar i Linköping

Since some years Linköping has invested in biogas production, mainly from offal's, residuals from food industry and manure. The municipality goes for biogas in the local traffic and in all transportation. It is also possible for private car owners to run their cars on biogas. The purpose of this essay is to perform a cost-benefit analysis and examine if the project has been beneficial from a social point of view. The effects have been identified, measured and monetarily valued. The essay is limited to include the year of 2006 only. It is also geographically limited to the region surrounding Linköping, where Svensk Biogas is operating, that is among other cities Norrköping, Motala and Örebro. The effects include for example air pollution reductions, changes in noise pollution, investment costs and increased running costs. The result shows that the investment in biogas has been profitable during the year of 2006. However, it is justified to be sceptical, because the essay might not include all effects and the one included might be wrongly valued.Linköpings kommun har sedan ett antal år satsat på biogasproduktion baserad på slakt- och livsmedelsindustrirester samt gödsel. Man driver hela den lokala bussflottan med biogas och har även som upphandlingskrav att samtliga transporter ska ske med biogasdrift. Dessutom har även privata bilister möjlighet att köpa biogas. Syftet med den här uppsatsen är att genom en kostnads- intäktsanalys undersöka huruvida satsningen har varit samhällsekonomiskt lönsam eller inte. Detta har skett genom att så många effekter som möjligt har identifierats, mätts och värderats för att slutligen åstadkomma en slutsumma. Arbetet har begränsats till att endast innefatta ett år, 2006, samt till regionen runt Linköping, närmare bestämt det område inom vilket producenten Svensk Biogas verkar. Biogasen transporteras till städer som Norrköping, Motala och Örebro. Effekterna inkluderar bland annat utsläppsminskningar, förändringar i bullernivåer, investeringskostnader och ökade driftskostnader. Resultatet visar på att satsningen, åtminstone under år 2006, har varit samhällsekonomiskt lönsamt. Men det är befogat att vara skeptiskt till själva slutsumman då dels denna uppsats inte nödvändigtvis innehåller samtliga relevanta effekter, dels därför att de grunder som beräkningarna baseras på inte är helt säkra. Nyckelord: kostnads

Om Viborg Kirkegaard

Intet resumé

Towards an\u2028 EU research and innovation policy agenda for nature-based solutions & re-naturing cities. Final report of the Horizon 2020 expert group on nature-based solutions and re-naturing cities.

1. Nature-based solutions harness the power and sophistication of nature to turn environmental, social and economic challenges into innovation opportunities. They can address a variety of societal challenges in sustainable ways, with the potential to contribute to green growth, 'future-proofing' society, fostering citizen well-being, providing business opportunities and positioning Europe as a leader in world markets. \u2028 2. Nature-based solutions are actions which are inspired by, supported by or copied from nature. They have tremendous potential to be energy and resource-efficient and resilient to change, but to be successful they must be adapted to local conditions. \u2028 3. Many nature-based solutions result in multiple co-benefits for health, the economy, society and the environment, and thus they can represent more efficient and cost-effective solutions than more traditional approaches. \u2028 4. An EU Research & Innovation (R&I) agenda on nature-based solutions will enable Europe to become a world leader both in R&I and in the growing market for nature-based solutions. For this, the evidence base for the effectiveness of nature-based solutions needs to be developed and then used to implement solutions. Both need to be done in conjunction with stakeholders. The potential for transferability and upscaling of solutions also requires further investigation. There is also a need to develop a systemic approach that combines technical, business, finance, governance, regulatory and social innovation. \u2028 5. Four principal goals have been identified that can be addressed by nature-based solutions: �� Enhancing sustainable urbanisation through nature-based solutions can stimulate economic growth as well as improving the environment, making cities more attractive, and enhancing human well-being. \u2028 �� Restoring degraded ecosystems using nature-based solutions can improve the resilience of ecosystems, enabling them to deliver vital ecosystem services and also to meet other societal challenges. \u2028 �� Developing climate change adaptation and mitigation using nature-based solutions can provide more resilient responses and enhance the storage of carbon. \u2028 �� Improving risk management and resilience using nature-based solutions can lead to greater benefits than conventional methods and offer synergies in reducing multiple risks. \u2028 6. Based on the four goals, seven nature-based solutions for R&I actions are recommended to be taken forward by the European Commission and Member States: �� Urban regeneration through nature-based solutions \u2028 �� Nature-based solutions for improving well-being in urban areas \u2028 �� Establishing nature-based solutions for coastal resilience \u2028 �� Multi-functional nature-based watershed management and ecosystem restoration \u2028 �� Nature-based solutions for increasing the sustainability of the use of matter and energy \u2028 �� Nature-based solutions for enhancing the insurance value of ecosystems \u2028 �� Increasing carbon sequestration through nature-based solutions \u2028This report was produced by the Horizon 2020 Expert Group on 'Nature-Based Solutions and Re- Naturing Cities', informed by the findings of an e-consultation and a stakeholder workshop. \u202

To automatically estimate the surface area coverage of carbon nanotubes on thin film transistors with image analysis : Bachelor’s degree project report

This report discuss the developement of a MATLAB-based tool for the analysis ofsurface area coverage of carbon nanotube networks from atomic force microscopyimages. The tool was compared with a manual method and the conclusion was that ithas, at least, the same accuracy as the manual mehtod, and it needs much less time forthe analysis. The tool couldn’t analyze images of carbon nanotube networks if theimages were to noisy or the networks to dense. The tool can help in the research ofthin-film transistors with carbon nanotube networks as the semiconducting channelmaterial

Factors Effecting Growth Trajectory of Walleye in Northern Wisconsin Lakes

Understanding population dynamics of sympatric fishes can be important for management. Walleye Sander vitreus are an important recreational species and a top predator in the systems they inhabit. Walleye growth can be highly variable among lakes suggesting that within-lake factors such as prey availability and quality are important. A statewide assessment of Cisco Coregonus artedi, an important prey species for Walleye, was recently conducted in Wisconsin lakes to better understand the status of this important species. We used data from a long-term standardized Walleye survey program (Ceded Territory of Wisconsin; CTWI) and the recent Cisco assessment to determine Walleye growth trajectories among lakes with and without Cisco. Analysis of the data from 87 populations of walleye across the CTWI revealed that female walleye reach greater asymptotic lengths in lakes where Cisco were detected, while male Walleye asymptotic length did not differ among lakes with and without Cisco detections. Common Walleye minimum length limits, 15 and 18 inches, were reached 0.6 and 0.9 years earlier in lakes with Cisco detections. Yellow Perch Perca flavescens, another common prey item for Walleye, mean length was significantly lower than lakes without Cisco. This could further enhance Walleye growth as they generally select for prey \u3c 130 mm. Therefore, managing to maintain Cisco habitat in these lakes could help ensure fast growth and trophy potential of Walleye in these systems

Influencer marketing ur en influencers perspektiv : Att samarbeta med företag på Instagram

Syfte och forskningsfrågor Syftet med denna uppsats är att undersöka hur samarbeten mellan företag och influencers kan skapa värde för influencern och dess varumärke. Vidare också vilka utmaningar de ställs inför i sitt yrke som influencer. Utifrån detta har två frågeställningar tagits fram: På vilket sätt skapar ett samarbete värde för en influencers varumärke? Vilka är de stora utmaningarna för en influencer i sitt arbete med influencer marketing? Metod Studien baseras på en kvalitativ forskningsmetod med en induktiv forskningsansats. Detta för att få en djupare förståelse för studiens forskningsområde och syfte. Det empiriska materialet består utav fyra semistrukturerade intervjuer med noggrant utvalda respondenter inom området. Slutsats Slutsatsen vi kan dra utifrån studiens resultat är att vi ser ett tydligt samband där samarbeten mellan företag och en influencer som verkar inom samma nisch med samma målgrupp är de samarbeten som ger störst värde för influencern på Instagram. Detta genom att det passar dess följare, målgrupp vilket kan generera i långsiktiga relationer med företag samt dess följare. På lång sikt ger detta bättre ekonomiska förutsättningar för influencern och på så sätt ett starkare varumärke och färre utmaningar i sitt arbete. Vi har också fått en förståelse för hur arbetet som en influencer ser ut genom de stora utmaningar som att få tiden att räcka till samt att ständigt behöva synas

Prediktion av Svenska Nyhetsartiklars Populäritet

In this work, 132,229 articles from a Swedish news publisher are used to explore news article popularity prediction. Linear-, k-Nearest Neighbor- and Support Vector Regression are evaluated using the two different metrics root mean squared error and R2. The problem is then relaxed into only attempting to rank the articles relative to each other. The prediction problem is also explored as a classification problem using the classes Low, Mid and High popularity. The classifiers evaluated are Naive Bayes and SVM using pre-defined features and using a Bag-of-words feature set. The results were analyzed to understand what information they can bring to the editors at the publisher and news agencies in general. The results clearly showed that the manually set metadata newsvalue had a large impact on article performance. A survey was done with editors to compare human prediction performance with the classifier performance. Although the SVM classifier performs with higher accuracy than the editors (59% vs 55%) the models are considered weak in their current state