The Neoproterozoic Visingsö Group of southern Sweden : lithology, sequence stratigraphy and provenance of the Middle Formation

The depositional setting of the Neoproterozoic Visingsö Group has long been a subject of discussion. This study aims to provide additional insights into the lithological composition and provenance of the sediments and to provide a sequence stratigraphic framework in order to define the depositional setting. It focuses on rocks belonging to the Middle Formation of the Visingsö Group located at the Näs locality, Visingsö, Sweden. The meth-ods employed included descriptions of lithology, stratigraphic variations and identification of sedimentary patterns through detailed facies logs. Furthermore LA-ICP-MS analyses of U/Pb ages on detrital zircons were performed to determine their provenance. The sediments are characterized by an immature composition, short transport distance and wave-dominated deposition. The sedimentary cycles are composed of coarsening-upwards intervals terminated by short transgressive episodes. Identified detrital ages of zircons are largely composed of ages that can be found in the region. The sequence stratigraphic framework is in accord with existing rift-basin models and showed that dep-osition was controlled by tectonic activity that created the space necessary for the deposition of sediments. This newly created space was filled in large parts by locally derived material with a smaller, more far-travelled, compo-nent.Det har länge pågått diskussioner om hur Visingsögruppen blev avsatt. Målet med den här studien är att få mer insikt i sedimentens litologiska sammansättning, provenans och genom att sätta upp ett sekvensstratigrafiskt ramverk kunna definiera depositionsprocesser. Studien fokuserade på sediment som tillhör den Mellersta formationen i Visingsögruppen, belägna vid Näs, Visingsö, Sverige. Metoderna som används inkluderar beskrivningar av litologi, stratigrafiska variationer och identifiering av sedimentära mönster genom detaljerade loggar. Vidare så användes LA-ICP-MS analyser för U/Pb dateringar av detritala zirkoner för att bestämma deras provenans. Sedimenten defineras av en omogen sammansättning, korta transportsträckor och vågdominerad avsättning. De sedimentära cyklerna är sammansatta av intervall med kontinuerligt ökande kornstorlek som avslutas med transgressiva episoder. De detritala zirkonernas åldrar stämmer i hög grad med åldrar som kan hittas regionalt. Det sekvensstratigrafiska ramverket överensstämmer med existerande modeller för riftbassänger och visar att avsättningen är kontrollerad av tektonik som skapar det nödvändiga utrymmet för att deposition ska kunna ske. Detta nyskapade utrymme fylldes igen av lokalt material och en mindre komponent av längre transporterat material

Drug eluting hydrogels design, synthesis and evaluation

Hydrogels have successfully proved themselves useful for drug delivery applications and several delivery routes have been developed over the years. The particular interest in this work was to design, synthesise and evaluate in situ forming drug eluting hydrogels, which have the potential to ameliorate the healing of cardiovascular diseases

The role of prostaglandin E2 (PGE 2) in toll-like receptor 4 (TLR4)-mediated colitis-associated neoplasia

<p>Abstract</p> <p>Background</p> <p>We have previously found that TLR4-deficient (TLR4-/-) mice demonstrate decreased expression of mucosal PGE ₂and are protected against colitis-associated neoplasia. However, it is still unclear whether PGE ₂is the central factor downstream of TLR4 signaling that promotes intestinal tumorigenesis. To further elucidate critical downstream pathways involving TLR4-mediated intestinal tumorigenesis, we examined the effects of exogenously administered PGE ₂in TLR4-/- mice to see if PGE ₂bypasses the protection from colitis-associated tumorigenesis.</p> <p>Method</p> <p>Mouse colitis-associated neoplasia was induced by azoxymethane (AOM) injection followed by two cycles of dextran sodium sulfate (DSS) treatment. Two different doses of PGE ₂(high dose group, 200 μg, n = 8; and low dose group, 100 μg, n = 6) were administered daily during recovery period of colitis by gavage feeding. Another group was given PGE ₂during DSS treatment (200 μg, n = 5). Inflammation and dysplasia were assessed histologically. Mucosal Cox-2 and amphiregulin (AR) expression, prostanoid synthesis, and EGFR activation were analyzed.</p> <p>Results</p> <p>In control mice treated with PBS, the average number of tumors was greater in WT mice (n = 13) than in TLR4-/- mice (n = 7). High dose but not low dose PGE ₂treatment caused an increase in epithelial proliferation. 28.6% of PBS-treated TLR4-/- mice developed dysplasia (tumors/animal: 0.4 ± 0.2). By contrast, 75.0% (tumors/animal: 1.5 ± 1.2, P < 0.05) of the high dose group and 33.3% (tumors/animal: 0.3 ± 0.5) of the low dose group developed dysplasia in TLR4-/- mice. Tumor size was also increased by high dose PGE ₂treatment. Endogenous prostanoid synthesis was differentially affected by PGE ₂treatment during acute and recovery phases of colitis. Exogenous administration of PGE ₂increased colitis-associated tumorigenesis but this only occurred during the recovery phase. Lastly, PGE ₂treatment increased mucosal expression of AR and Cox-2, thus inducing EGFR activation and forming a positive feedback mechanism to amplify mucosal Cox-2.</p> <p>Conclusions</p> <p>These results highlight the importance of PGE ₂as a central downstream molecule involving TLR4-mediated intestinal tumorigenesis.</p

Cellulose: from biocompatible to bioactive material

International audienceSince the papyri, cellulose has played a significant role in human culture, especially as paper. Nowadays, this ancient product has found new scientific applications in the expanding sector of paper-based technology. Among paper-based devices, paper-based biosensors raise a special interest. The high selectivity of biomolecules for target analytes makes these sensors efficient. Moreover, simple paper-based detection devices do not require hardware or specific technical skill. They are inexpensive, rapid, user-friendly and therefore highly promising for providing resource-limited settings with point-of-care diagnostics. The immobilization of biomolecules onto cellulose is a key step in the development of these sensing devices. Following an overview of cellulose structural features and physicochemical properties, this article reviews current techniques for the immobilization of biomolecules on paper membranes. These procedures are categorized into physical, biological and chemical approaches. There is no universal method for biomolecule immobilization. Thus, for a given paper-based biochip, each strategy can be considered

Surface modification of cellulose materials : from wood pulps to artificial blood vessels

This thesis describes the improvement of two radically different cellulose materials, paper and artificial blood vessels, constructed from two diverse cellulose sources, wood pulp and Acetobacter xylinum. The improvement of both materials was possible due to the natural affinity of the hemicellulose xyloglucan for cellulose. Chemical and mechanical pulps were treated with xyloglucan in the wet-end prior to hand sheet formation or by spray application of dry hand sheets, loading a comparable amount of xyloglucan. The tensile strength increases for the wet-end treatment and spray application were 28% and 71% respectively for bleached soft wood, compared to untreated sheets (20.7 Nm/g). The corresponding strength increases for hand sheets made of thermo-mechanical pulp were 6% and 13% respectively compared to untreated sheets (42.4 Nm/g). The tendency for chemical pulp to be superior to mechanical pulp with respect to strength increase was valid even for tear strength and Scott-Bond. These results suggest, in agreement with other studies, that adhesion of xyloglucan to wood fibres is dependent on their degree of surface lignification. Also, a method was developed to increase the blood compatibility of artificial blood vessels constructed of bacterial cellulose. Xyloglucan was covalently linked to the endothelial cell adhesion motif (Arg-Gly-Asp). To obtain this, new solid-phase coupling chemistry was developed. Xyloglucan oligosaccharides (XGO) were transformed into XGO-succinamic acid via the corresponding XGO--NH2 derivative prior to coupling with the N-terminus of the solid-phase synthesised Gly-Arg-Gly-Asp-Ser peptide. The resin-bound glyco-peptide was then cleaved and enzymatically re-incorporated into high molecular weight xyloglucan. The glyco-peptide was further adsorbed onto bacterial cellulose scaffolds, increasing the adhesion and proliferation of endothelial cells and therefore blood compatibility.QC 2010110

Surface modification of cellulose materials : from wood pulps to artificial blood vessels

This thesis describes the improvement of two radically different cellulose materials, paper and artificial blood vessels, constructed from two diverse cellulose sources, wood pulp and Acetobacter xylinum. The improvement of both materials was possible due to the natural affinity of the hemicellulose xyloglucan for cellulose. Chemical and mechanical pulps were treated with xyloglucan in the wet-end prior to hand sheet formation or by spray application of dry hand sheets, loading a comparable amount of xyloglucan. The tensile strength increases for the wet-end treatment and spray application were 28% and 71% respectively for bleached soft wood, compared to untreated sheets (20.7 Nm/g). The corresponding strength increases for hand sheets made of thermo-mechanical pulp were 6% and 13% respectively compared to untreated sheets (42.4 Nm/g). The tendency for chemical pulp to be superior to mechanical pulp with respect to strength increase was valid even for tear strength and Scott-Bond. These results suggest, in agreement with other studies, that adhesion of xyloglucan to wood fibres is dependent on their degree of surface lignification. Also, a method was developed to increase the blood compatibility of artificial blood vessels constructed of bacterial cellulose. Xyloglucan was covalently linked to the endothelial cell adhesion motif (Arg-Gly-Asp). To obtain this, new solid-phase coupling chemistry was developed. Xyloglucan oligosaccharides (XGO) were transformed into XGO-succinamic acid via the corresponding XGO--NH2 derivative prior to coupling with the N-terminus of the solid-phase synthesised Gly-Arg-Gly-Asp-Ser peptide. The resin-bound glyco-peptide was then cleaved and enzymatically re-incorporated into high molecular weight xyloglucan. The glyco-peptide was further adsorbed onto bacterial cellulose scaffolds, increasing the adhesion and proliferation of endothelial cells and therefore blood compatibility.QC 2010110

Travelling Stockholm from underneath : A journey of light

The report Stockholm city’s regional biking plan presents information of a continuously rising numbers ofcyclists in central Stockholm. However, the central parts of Stockholm have not now, or in the near future,the capacity or structure to provide a functional as well as safe traffic situation, especially for cyclists. Theincreasing demand from traffic of the commuter street network in central Stockholm make the 6 km longunderground maintenance tunnel along the newly build Citybanan commuter train tracks a possible andinteresting alternative for safe, fast and easy bicycle travelling underneath Stockholm. The tunnel stretchesfrom Fatbursparken to Tomteboda, with exits/entrances along the route in central parts of Stockholm[Fig 1.]There are several examples in the world where former car, train and maintenance tunnels are used as bikingtunnels. The longest existing example is the Croix Rousse tunnel in Lyon, France (2013). A 1,3 km longtunnel with separate lanes for cyclists, pedestrians and commuter busses, which also functions as anevacuation tunnel to the parallel car tunnel. Another example is the Lugaritz-Morland bicycle tunnel in thecity of San Sebastian, Spain (2009), which is a former railway tunnel (850 metres) that connects twoneighbourhoods in the city.The specific conditions a tunnel have with no daylight and limited access, give the lighting designer theimportant task to shape the space using light.Light is the factor that makes us see the world, our visual ability is depending on the light. Light has theability to reveal and transform the character of a space and influence how the observer experiences thesituation, both physically (by vision) and psychologically (emotional experiences as comfort and feeling ofsafety). Therefore a good visual condition in public space, traffic as well as enclosed spaces like tunnels, arevery important and a basic need for humans in the city.The aim with this thesis was to develop a lighting strategy and proposal for the maintenance tunnel ofCitybanan in Stockholm, based on literature and case studies research, a full-scale light observation by areference group in a tunnel context as well as research by questionnaires. The primary purpose of the fullscalelight study was to confirm literature research hypotheses about the importance of light distributionand experienced spatial atmosphere in relation to psychological effects, as well as the importance of lightgiving information. Findings confirm and shows that light distribution have a great impact on how theobservers experience the space visually, as well as emotionally. Findings also show that light can influencepeople’s behaviour to intuitively slow down or be alert. Further this thesis results show that giving a spaceit’s own identity by collaboration between light, colour and architectural elements have a great impact onthe psychological experiences of a space regarding safety, comfort and social interaction, crucial factors in atunnel environment for cyclists.The thesis results in a concept presented in the Proposal chapter, based on design principles and a lightingstrategy where a combination of light typologies is used to create a human centred and comfortableenvironment. Light is used as guiding element and for spatial understanding to create comfort and supportsocial interaction. In addition the concept includes a theme used as inspiration in the lighting strategy tocreate a connection on a human scale between the cyclist and the space. The theme is based on a commonpreference of the reference group, as well as my personal, for the ideal dream biking environment;In the nature. Experiencing for example the variation of light filtered through the leaves, the sunset and theabsence of traffic.The aim with the proposal is to transform the tunnel to an attractive bicycle route for daily cyclists inStockholm, as well as being an interesting tourist attraction.- A large underground landmark and art piece stretching under the city of Stockholm

One Compiler to Rule Them All : Extending the Storm Programming Language Platform with a Java Frontend

The thesis aims to develop a method for extending the language platform Storm with a Java frontend.The project was conducted using an Action Research methodology and highlights triumphs andchallenges. Despite the significant overhead related to note generation and problem statementformulation, this methodology proved beneficial in identifying problems and providing the framework tosolve them. The first research question (RQ.1) evaluates to what extent the language platform Storm is suitable forimplementing the object oriented language Java. Using Storm, only a BNF and a specification for three-address code instructions are needed. Despite encountering difficulties during the implementation, theplatform offers tools that allow comprehensive customization of the new language's intended behaviorand functionality. The second research question (RQ.2) explores a suitable method for implementing a new language inStorm. It is suggested to first implement a foundational structure comprising of statements, blocks,scope handling and variable declarations. From this foundation, new functionalities can be graduallyintroduced and tested by connecting them to the appropriate location in the structure. When allfunctionality is added and tested a refactoring step can take place to modify the BNF if needed

Travelling Stockholm from underneath : A journey of light

The report Stockholm city’s regional biking plan presents information of a continuously rising numbers ofcyclists in central Stockholm. However, the central parts of Stockholm have not now, or in the near future,the capacity or structure to provide a functional as well as safe traffic situation, especially for cyclists. Theincreasing demand from traffic of the commuter street network in central Stockholm make the 6 km longunderground maintenance tunnel along the newly build Citybanan commuter train tracks a possible andinteresting alternative for safe, fast and easy bicycle travelling underneath Stockholm. The tunnel stretchesfrom Fatbursparken to Tomteboda, with exits/entrances along the route in central parts of Stockholm[Fig 1.]There are several examples in the world where former car, train and maintenance tunnels are used as bikingtunnels. The longest existing example is the Croix Rousse tunnel in Lyon, France (2013). A 1,3 km longtunnel with separate lanes for cyclists, pedestrians and commuter busses, which also functions as anevacuation tunnel to the parallel car tunnel. Another example is the Lugaritz-Morland bicycle tunnel in thecity of San Sebastian, Spain (2009), which is a former railway tunnel (850 metres) that connects twoneighbourhoods in the city.The specific conditions a tunnel have with no daylight and limited access, give the lighting designer theimportant task to shape the space using light.Light is the factor that makes us see the world, our visual ability is depending on the light. Light has theability to reveal and transform the character of a space and influence how the observer experiences thesituation, both physically (by vision) and psychologically (emotional experiences as comfort and feeling ofsafety). Therefore a good visual condition in public space, traffic as well as enclosed spaces like tunnels, arevery important and a basic need for humans in the city.The aim with this thesis was to develop a lighting strategy and proposal for the maintenance tunnel ofCitybanan in Stockholm, based on literature and case studies research, a full-scale light observation by areference group in a tunnel context as well as research by questionnaires. The primary purpose of the fullscalelight study was to confirm literature research hypotheses about the importance of light distributionand experienced spatial atmosphere in relation to psychological effects, as well as the importance of lightgiving information. Findings confirm and shows that light distribution have a great impact on how theobservers experience the space visually, as well as emotionally. Findings also show that light can influencepeople’s behaviour to intuitively slow down or be alert. Further this thesis results show that giving a spaceit’s own identity by collaboration between light, colour and architectural elements have a great impact onthe psychological experiences of a space regarding safety, comfort and social interaction, crucial factors in atunnel environment for cyclists.The thesis results in a concept presented in the Proposal chapter, based on design principles and a lightingstrategy where a combination of light typologies is used to create a human centred and comfortableenvironment. Light is used as guiding element and for spatial understanding to create comfort and supportsocial interaction. In addition the concept includes a theme used as inspiration in the lighting strategy tocreate a connection on a human scale between the cyclist and the space. The theme is based on a commonpreference of the reference group, as well as my personal, for the ideal dream biking environment;In the nature. Experiencing for example the variation of light filtered through the leaves, the sunset and theabsence of traffic.The aim with the proposal is to transform the tunnel to an attractive bicycle route for daily cyclists inStockholm, as well as being an interesting tourist attraction.- A large underground landmark and art piece stretching under the city of Stockholm

One Compiler to Rule Them All : Extending the Storm Programming Language Platform with a Java Frontend

The thesis aims to develop a method for extending the language platform Storm with a Java frontend.The project was conducted using an Action Research methodology and highlights triumphs andchallenges. Despite the significant overhead related to note generation and problem statementformulation, this methodology proved beneficial in identifying problems and providing the framework tosolve them. The first research question (RQ.1) evaluates to what extent the language platform Storm is suitable forimplementing the object oriented language Java. Using Storm, only a BNF and a specification for three-address code instructions are needed. Despite encountering difficulties during the implementation, theplatform offers tools that allow comprehensive customization of the new language's intended behaviorand functionality. The second research question (RQ.2) explores a suitable method for implementing a new language inStorm. It is suggested to first implement a foundational structure comprising of statements, blocks,scope handling and variable declarations. From this foundation, new functionalities can be graduallyintroduced and tested by connecting them to the appropriate location in the structure. When allfunctionality is added and tested a refactoring step can take place to modify the BNF if needed