Organic bioelectronic devices to control cell signalling

The nervous system consists of a network of specialized cells that coordinate the actions of the body by transmitting information to and from the brain. The communication between the nerve cells is dependent on the interplay of both electrical and chemical signals. As our understanding of nerve cell signalling increases there is a growing need to develop techniques capable of interfacing with the nervous system. One of the major challenges is to translate between the signal carriers of the nervous system (ions and neurotransmitters) and those of conventional electronics (electrons). Organic conjugated polymers represent a unique class of materials that can utilize both electrons and ions as charge carriers. Taking advantage of this combined feature, we have established a novel communication interface between electronic components and biological systems. The organic bioelectronic devices presented in this thesis are based on the organic electronic ion pump (OEIP) made of the conducting organic polymer poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS). When electronically addressed, electrochemical redox reactions in the polymer translate electronic signals into electrophoretic migration of ions. We show that the device can transport a range of substances involved in nerve cell signaling. These include positively charged ions, neurotransmitters and cholinergic substances. Since the devices are designed to be easily incorporated in conventional microscopy set-ups, we use Ca2+ imaging as readout to monitor cell responses. We demonstrate how electrophoretic delivery of ions and neurotransmitters with precise, spatiotemporal control can be used to modulate intracellular Ca2+ signaling in neuronal cells in the absence of convective disturbances. The electronic control of delivery enables strict control of dynamic parameters, such as amplitude and frequency of Ca2+ responses, and can be used to generate temporal patterns mimicking naturally occurring Ca2+ oscillations. To enable further control and fine-tuning of the ionic signals we developed the electrophoretic chemical transistor, an analogue of the traditional transistor used to amplify and/or switch electronic signals. We thereby take the first step towards integrated chemical circuits. Finally, we demonstrate the use of the OEIP in a new “machine-to-brain” interface. By encapsulating the OEIP we were able to use it in vivo to modulate brainstem responses in guinea pigs. This was the first successful realization of an organic bioelectronic device capable of modulating mammalian sensory function by precise delivery of neurotransmitters. Our findings highlight the potential of communication interfaces based on conjugated polymers in generating complex, high-resolution, signal patterns to control cell physiology. Such devices will have widespread applications across basic research as well as future applicability in medical devices in multiple therapeutic areas

Simulation of Diamond Surface Chemistry: Reactivity and Properties

The diamond material possesses very attractive properties, such as superior electronic properties (when doped), in addition to a controllable surface termination. During the process of diamond synthesis, the resulting chemical properties will depend not only on the adsorbed species but also on the type of substitutional doping element. The combination of adsorbate and dopant will thus have the ability to influence both the chemical and electronic properties of a diamond surface. All resulting (and interesting) properties of doped and terminated diamond surfaces make it clear that these types of material modifications are very important for a variety of applications that are based on photoactivated chemical processes. Theoretical modeling has been shown to act as an important scientific tool in explaining and predicting experimental results. Simulation of the dependence of, e.g. surface termination and doping on diamond material properties, is expected to give important information about various surface electronic properties (like photo-induced surface electrochemistry)

The dual weighted residuals approach to optimal control of ordinary differential equations

The methodology of dual weighted residuals is applied to an optimal control problem for ordinary differential equations. The differential equations are discretized by finite element methods. An a posteriori error estimate is derived and an adaptive algorithm is formulated. The algorithm is implemented in Matlab and tested on a simple model problem from vehicle dynamics

Square Functions for Ritt Operators in L1L^1

$T$ is a Ritt operator in $L^p$ if $\sup_n n\|T^n-T^{n+1}\|<\infty$. From \cite{LeMX-Vq}, if $T$ is a positive contraction and a Ritt operator in $L^p$, $1<p<\infty$, the square function $\left( \sum_n n^{2m+1} |T^n(I-T)^{m+1}f|^2 \right)^{1/2}$ is bounded. We show that if $T$ is a Ritt operator in $L^1$, $$Q_{\alpha,s,m}f=\left( \sum_n n^{\alpha} |T^n(I-T)^mf|^s \right)^{1/s}$$ is bounded $L^1$ when $\alpha+1<sm$, and examine related questions on variational and oscillation norms

Experiments and calibration of a bond-slip relation and efficiency factors for textile reinforcement in concrete

Textile reinforcement yarns consist of many filaments, which can slip relative each other. At modelling of the global structural behaviour, interfilament slip in the yarns, and slip between the yarns and the concrete can be considered by efficiency factors for the stiffness and strength of the yarns, and by applying a bond-slip relation between yarns and concrete. In this work, an effective and robust method for calibration of such models was developed. Two-sided asymmetrical pull-out tests were carried out, with varying embedment lengths designed to obtain both pull-out and rupture of the textile as failure mode. The efficiency factors for strength and stiffness of the textile were very similar, 34% and 35% respectively. This indicates the stress distribution within a yarn to be uneven in a similar manner for small and large stress levels, and that interfilament slip has a larger influence than variation of filaments’ strength

e-Government for all – Norm-critical Perspectives and Public Values in Digitalization

There are hopes that e-government will bring many benefits, including efficiency, democratization, participation, and emancipation of citizens. However, despite some evidence that supports these claims there are also cases that digitalization can exclude citizens and build new barriers. This is a special challenge for already disadvantaged groups falling outside the norms. In this study we approach the notion of a norm-critical perspective in relation to e-government through a review of literature in combination with action research oriented workshops. From this we conclude that there is a need for more norm-critical perspectives in research on e-government, as most research today focuses on socio-economic digital-divide issues. We also show that it is difficult for involved actors to see beyond the norms and be norm-critical since the norms are embedded into the practices, which in this case, e-government has developed and used

Attityder beträffande bevarande i två olika vildmarksområden i Kenya

All over the world, scientists agree that to succeed with a conservation project, it is important to have a good relationship with the local people. If they do not receive a good impression of the project, they will not be willing to collaborate and the project will probably fail. According to previous studies, there are different factors affecting attitudes to conservation, like the level of education of the participant. Many studies have shown that the higher education the people have, the more positive attitude they have to adjacent conservation areas. Economical factors are also important, it is often stated that having more money results in a better attitude. The source of the income also has an effect. Those who earn money from conservation are more positive than those who earn money from other sources. Age and gender also affect the attitudes. In this study the attitudes of local people in two different areas in Kenya was examined. There are conservation work going on in both areas but they area managed in different ways. In the study a group of employees was also included, who all worked with conservation in one of the two areas. In general the results agreed with the literature and the participant thought that the adjacent conservation area worked well and fulfilled its purpose. As expected was the group with the employees most positive towards conservation. There was also a big difference in attitudes between those who had an income from the conservation area and/or an education and those who had neither. Having both income and education gave the most positive attitude. This study indicates that education is a very important part in conserving animals and plants. At the same time it is also very important that the local people can receive their rightful part of the benefits and income that conservation can generate

Omplacering av hundar

I the year of 2008 there were more than 60 000 purebred dogs newly registered in the Swedish Kennel Club. In addition there are a lot of mixed breed dogs and in the year of 2006 it was estimated that there were over 700 000 dogs in Sweden. In today’s society it is not unusual that people change their life situation by moving, getting a new job or starting a family. Because of this there is a risk of rehoming for dogs owned by these people. In Sweden dogs are among others rehomed by advertising or by rehoming organisations. A study of research was done to see how a dog is affected by being rehomed and being in a shelter for rehoming. Research about Swedish rehoming organisations or shelters does not exist and because of this interviews were done with some of these. The organisations that were interviewed worked in different ways. Some had their own shelters, some had the dogs in temporary homes or they just mediated contact information between sellers and buyers. One of the big questions before this study started was if it is possible to see any patterns in which dogs that people want to rehome and why. This was done partly by asking what the organisations thought and by analysing data that was collected from advertisements which were found on www.blocket.se during the month of January. The results of the advertisements were among others that there was no difference in gender of the dogs (p=0,165), that purebred dogs were more common than mixed breeds (p<0,001) and that there were more dogs between six months and two years of age than younger than six months and over two years of age. Other results from the advertisements shown in this paper are which breeds, and those breeds in mixed breed dogs that were most common and what reasons people report for rehoming their dog

Lammproduktion på nio ekologiska gårdar i västra Sverige

The purpose with this study was to analyze the possibilities to produce organic lambs and to hihglight the most common difficulties in such a production system. A description of current organic and conventional lamb production systems was conducted, both from Sweden and from some other countries. The Department of Animal Environment and Health at SLU in Skara performed the project together with The County Board of Agriculture in Västra Götaland and Värmland and The Swedish Animal Health Service. The project lasted from 2002 to 2004. The student report contains the years 2002 and 2003. In the year of 2003 there were 210 000 adult sheep in Sweden, of which 16 400 adult sheep were certified by KRAV. Of the different countries in Sweden, Västra Götaland and Gotland had the largest number of sheep, 14 and 13 per cent of the total number. The total number and the number of certified sheep has increased whereas the total number and number of certified sheep producers have decreased during the last few years. In the year of 2003, the average herd size was 27,7 adult sheep while the average certified herd size was 57,6 adult sheep. Feeding strategies in organic and conventional lamb productions are quite similar to each ther. Legumes in mixture with grasses are used as forages in organic production because of the ability of legumes to fixate nitrogen. According to the rules of KRAV, a maximum of 40 per cent of the daily intake of dry matter can be provided as concentrate. However, during the first three months of lactation the maximum amount of concentrate in the ration is 50 per cent. Lambs are normally weaned when they are three months old, which means that the ewe can be fed with 50 % per cent of concentrate during their whole lactation. Hexane extracted feeds (meal) are prohibited to use as a source of protein in organic production. The feeding ration must thereby be completed by protein feed that are approved by KRAV, such as rapeseed, peas, field beans and lupine. Intestinal parasites occur in lungs, abomasum, gut and liver in sheep. Parasite infections are mostly a problem for the lambs, ewes has normally developed immunity. However, the barbers' worm can cause sickness in ewes, especially during lambing or at other times when the ewe's condition is low. The ewe's immunity does not, however, mean that they're free om parasites. They can carry parasites that through their manure pass on to the pasture where they can affect the lambs. By letting different animals, for example cattle and sheep, graze the same pasture simultaneously or by using rotational grazing the risks for parasite infections can be decreased. Parasites are in most cases specific to one species. Nine farms in western Sweden participated in the study. The herd size varied between 30 and 140 ewes. The breeds were mostly crosses with Fine wool or Texel but also pure bred Gotlandsheep was used. The farms used different lambing seasons. The ewes were lambing from January until May and in September. Five of the herds had the ewes lambing in the winter, three in the spring, two in the summer and two in the autumn. The farms were visited five times a year during the project. Lambing time, number of lambs per ewe, lamb weights and lamb age at weaning were registered. Slaughter data were collected from the abbatoir. Results from 2002 and 2003 are shown as birth weight, weight at 110 days of age, age at slaughter, body conformation and fat content of the carcass. Parasite status in the herds and methods that were used to reduce the risks for parasite infections were studied. The frequency of parasites where registered with assistance from the Swedish Animal Health Association. Several farms let the sheep graze together with cattle or horses and/or rotate sheep and cattle for grazing. Despite this, six of the farms had sheep affected by the barbers' worm. Intestinal parasites are thereby a large problem in organic lamb production. To reduce the risks for infections that cause production losses it is important to take faecal samples from the ewes before the grazing period to find out the status of parasites in the herd. Except for the barbers worm, there also were some problems with lung worm, large liver fluke and giardia. It is important to have control over the lambs and weigh them once in a while during the grazing period. By weighing the lambs you can discover if the growth rate of the lambs has been reduced, which can be a sign of a parasite infection. In the last years, forages that contain condensed tannins, for example birdsfoot trefoil, been noticed as feed for ruminants. Condensed tannins reduce the risk for parasite infections. However, studies at Röbäcksdalen, The Swedish University of Agricultural Sciences, Umeå, have not shown any effects of tannins on prevalence of parasite infections under Swedish conditions. Feeding rations for lactating ewes in 2003 were made for five herds in the study. The feeding rations were based on nutrient analyses of the forages and concentrates. Random bales of thilage that were used as feed were weighed to estimate the amount of silage offered to the animals. Feeding rations were compared to the nutrient requirements of lactating ewes. It was shown that the ewes on most of the farms had sufficient provisions of protein and energy. The most common concentrates were grain mixtures combined with a protein mixture. Today lambs are produced almost the whole year round. What production model that should be used should be based on the condition of the farm. In a production system with lambs born in the winter the lambs are raised intensively and the aim is to have them slaughtered before the grazing period starts. The ewes can then be used as nature conservators on semi-natural grasslands. Large amounts of pasture, both for ewes and lambs are needed, in a production model with spring born lambs. In a production system with summer born lambs the ewes can e grazing semi-natural grasslands in spring whereas they during summer and autumn during their late pregnancy and lactation have a demand for a high quality pasture. A production witlambs born in the autumn is based on the idea to let ewes graze regrowth pastures in the autumn during late pregnancy and lactation. After the grazing period the aim is to feed ewes and lambs with forages (silage) only. The lambs are raised extensively and are slaughtered inthe spring. Carcasses of lambs are judged after weight, form and content of fat in the body. The form is judged according to the five main classes of the EUROP-system, E, U, R, O and P that is omplemented with + and -. The content of fat is judged in the same way, with 1, 2, 3, 4 and 5 and is complemented with + and -. The requirements to receive the extra KRAV supplement were in 2002 and 2003 a conformation class from E+ to O, fat content of 2-to 3 and a slaughter weight between 14 and 25,9 kg. In this study, results form lambs born 2002 and 2003 were presented. The results were presented separately for ewe and ram lambs, winter born, spring born and autumn born. Lambs that were born in autumn were only few in the study and it is hard to make any conclusions for that kind of production model. However, it is an interesting model that needs to be studied more extensively. To compare how the growth rate differed among farms growth rate was calculated from birth weight, slaughter weight and an expected dressing percentage oft 40 per cent. The daily growth rate varied between 145 and 339 g. The large difference is caused by the conditions on the farms and the aim of the production model. Low daily growth rates are also certainly caused by parasite infections. There are great opportunities to succeed with organic as well as conventional lamb production. The largest problem with lamb production is parasite infections of the lambs, even when methods have been used to reduce the risks for infections. You have to control the parasite status of the lambs by weighing and by taking faecal samples during the grazing periods. When choosing a model you should take into account the conditions of the farm including types of buildings and pastures.Syftet med studien var att undersöka möjligheterna att bedriva ekologisk lammproduktion samt var de största svårigheterna i en sådan produktion fanns. Nio gårdar i västra Sverige deltog i dokumentationen. En nulägesbeskrivning av lammproduktion, både konventionell och ekologisk, i Sverige och i några andra länder genomfördes. År 2003 fanns 210 000 vuxna får i Sverige, varav 16 400 vuxna får var anslutna till KRAV. Av de olika länen var det Västra Götaland och Gotland som hade flest får, 14 respektive 13 % av det totala antalet i landet. Det totala antalet och KRAV-godkända får har under senare år ökat medan det totala antalet och antalet KRAV-godkända företag med får minskat. År 2003 hade medelbesättningen 27,7 vuxna får medan den KRAV-anslutna medelbesättningen hade 57,6 vuxna djur. Utfodring inom ekologisk lammproduktion skiljer sig inte så mycket från den konventionella. I ekologisk produktion utnyttjar man luftens kväve genom att ha ett stort baljväxtinslag i vallen. Till tackor får högst 40 % av det dagliga torrsubstansintaget i foderstaten utgöras av kraftfoder enligt KRAVs regler. Under de tre första månaderna under digivningen får kraftfoderandelen höjas till 50 %. Lamm avvänjs vanligtvis vid tre månaders ålder vilket betyder att tackan under hela digivningen kan utfodras med 50 % kraftfoder. Numera får inte hexanextraherade fodermedel användas som proteinkälla i ekologisk produktion, vilket gör att många proteinfodermedel inte kan användas. Därför måste kravgodkända kraftfodermedel såsom raps, ärter, åkerböna eller lupin användas. Inälvsparasiter hos får förekommer i lungor, löpmage, tarm och lever. Parasitangrepp är främst ett problem hos lammen då tackor i regel utvecklat immunitet. Stora magmasken är dock ett undantag, då den även kan orsaka sjukdom hos tackor i samband med lamning eller under annan tidpunkt då de är i sämre kondition. Då tackorna är immuna betyder det inte att de är parasitfria. De kan bära på parasiter som via träcken kommer ut på betet och sedan angriper lammen. Genom sambete och växelbete med andra djurslag kan man minska riskerna för parasitangrepp. Parasiterna är i de flesta fall artspecifika, d v s angriper ett djurslag. Genom att de olika djurslagen betar varandras rator betar de varandras parasiter. Nio gårdar belägna i västra Sverige ingick i studien. Besättningsstorleken var mellan 30- 140 tackor vardera. Raserna var mestadels korningar med finull eller texel samt renrasiga gotlandsfår. Olika lamningstidpunkter tillämpades på gårdarna. Tackorna lammade från januari till maj samt i september. Fem av gårdarna hade vinterlammande tackor, tre vårlammande, två sommarlammande och två höstlammande. De resultat som redovisas för två år är lammens födelsevikt, vikt vid 110-dagars ålder, ålder vid slakt, slaktvikt, formklass, fettklass samt hur stor andel av lammen som klarade gränsen för märkeskvalitet. Utöver slaktresultaten studerades även hur parasitstatusen såg ut på gårdarna och vad som gjordes för att minska risken för parasitangrepp. På flertalet av gårdarna i studien tillämpades sambete och/eller växelbete med nötkreatur och/eller hästar. Trots detta var det på sex av gårdarna som fåren fick angrepp av stora magmasken. Inälvsparasiter är således ett stort problem inom ekologisk lammproduktion. För att motverka risken för parasitangrepp med påföljande produktionsförluster är det därför viktigt att ta träckprov på tackor innan betessläppning för att ta reda på parasitstatusen i besättningen. Förutom stora magmasken förekom även enstaka problem med lungmask, stora leverflundran och giardia. Det är även viktigt att ha lammen under uppsikt och väga dem kontinuerligt under betessäsongen. Genom att väga lammen kan man tidigt upptäcka om tillväxten avtagit, då detta kan vara tecken på parasitangrepp. På senare år har växter innehållande kondenserade tanniner, exempelvis käringtand, uppmärksammats som foderväxt. Kondenserade tanniner sägs minska risken för parasitangrepp. Studier vid Röbäcksdalen har dock inte gett några resultat som visar att det gäller under svenska förhållanden. För fem av gårdarna i projektet beräknades en foderstat till tackorna under digivningen 2003. Foderstaten baserades på analyser av vall- och kraftfoder samt angiven kraftfodergiva från lantbrukarna och stickprovsvägning av rundbalsensilaget som utfodrades. Foderstaterna jämfördes sedan med normen för digivande tackors näringsbehov. På de flesta gårdarna visade det sig att tackorna näringsförsörjde sig tämligen väl beträffande energi- och protein. Vanligaste kraftfodret var spannmålsblandning i kombination med någon proteinmix. Lamm produceras i stort sett under hela året. Gårdens förutsättningar bör avgöra vilken produktionsmodell som väljs. Vid vinterlamning föds lammen upp intensivt och målsättningen är att de skall slaktas före betessläppning. Tackor utan lamm kan då med fördel beta naturbetesmark. Produktion av vårlamm kräver stora betesarealer för både tackor och lamm. Vid sommarlamning kan tackor beta naturbeten under våren, medan de under resterande del av betesperioden kräver ett näringsrikt åkermarksbete. Vid höstlamning får tackorna beta åteväxtbete under hösten. Efter installning utfodras enbart grovfoder till både tackor och lamm. Lammen föds då upp mer extensivt och går till slakt under våren. Vid slakt bedöms lammens slaktkropp efter vikt, formklass och fettansättning. Formen bedöms enligt EUROP-systemets fem huvudklasser, E, U, R, O och P som kompletteras med + och -. Slaktkroppens fettinnehåll bedöms på liknande sätt med klasserna 1, 2, 3, 4 och 5 som kompletteras med + och -. Kvalitetsgränserna för att erhålla KRAV-tillägget var mellan år 2002 och 2004 formklass E+ till O, fettgrupp 2- till 3 och en slaktvikt mellan 14-25,9 kg. I studien bearbetades slaktresultaten för lamm födda år 2002 och 2003. Resultaten är uppdelade för bagglamm respektive tacklamm samt vinterfödda, vårfödda respektive höstfödda lamm. Då antalet höstfödda lamm i studien var relativt få är det svårt att dra några slutsatser av den produktionsformen Det är dock en intressant uppfödningsmodell där mer studier skulle behövas. För att jämföra hur tillväxten skiljde sig mellan de olika gårdarna beräknades tillväxten från födsel till slakt fram med hjälp av födelsevikt, slaktvikt och ett uppskattat slaktutbyte på 40 %. Den dagliga tillväxten varierade mellan 145 och 339 g. Den stora skillnaden i tillväxt beror på gårdens förutsättningar och vilket mål med produktionen besättningarna hade. Låg tillväxt beror säkerligen även på parasitangrepp. Förutsättningar finns att lyckas lika bra med ekologisk som med konventionell lammproduktion. Vad som kan ställa till problem är att lammen i vissa fall kan drabbas av parasitinfektion trots att åtgärder vidtagits för att förhindra detta. Man måste vara uppmärksam på lammens parasitstatus genom regelbunden vägning av lammen och träckprovstagning under betessäsongen. Vid valet av produktionsmodell bör man utgå från gårdens förutsättningar, vilken typ av byggnader som finns samt vilken sorts beten man har

Relatives’ participation in everyday care in special care units for persons with dementia

Background: Research concerning relatives’ participation in the everyday care related to persons living in special care units for persons with dementia is limited. Research questions: To examine relatives’ participation in their near one’s everyday care, the level of burden experienced and important factors for participation, in this special context. Design: The study had a cross-sectional design, and data collection was carried out by means of a study-specific questionnaire. Participants and context: A total of 233 relatives from 23 different special care units participated. Ethical consideration: The study was approved by the Norwegian Social Science Data Services. Results: A great majority of relatives reported that they visited weekly and were the resident’s spokesperson, but seldom really participated in decisions concerning their everyday care. Participation was seldom reported as a burden. Discussion: This study indicated that relatives were able to make a difference to their near one’s everyday life and ensure quality of care based on their biographical expertise, intimate knowledge about and emotional bond with the resident. Since knowing the resident is a prerequisite for providing individualised care that is in line with the resident’s preferences, information concerning these issues is of utmost importance. Conclusion: This study prompts reflection about what it is to be a spokesperson and whether everyday care is neglected in this role. Even though relatives were satisfied with the care provided, half of them perceived their participation as crucial for the resident’s well-being. This indicated that relatives were able to offer important extras due to their biographical expertise, intimate knowledge about and emotional bond with the resident. Good routines securing that written information about the residents’ life history and preferences is available and used should be implemented in practice