<p>Huvudsyftet med arbetet har varit att undersöka potentialen för värmedriven kylproduktion, dvs. absorptionskyla, i Linköpings energisystem. Bakgrunden är att många energibolag söker efter nya avsättningsområden för fjärrvärme pga. det överskott på värme som finns sommartid i energisystem med kraftvärme. Dessutom förväntas elpriserna fortsätta stiga då Sverige med stor sannolikhet kommer att följa resten av Europa och gå från ett energidimensionerat system till ett effektdimensionerat system. Till följd av detta blir energieffektiviserande åtgärder allt viktigare och absorptionskyla innebär att mer el kan produceras i ett system med kraftvärme, istället för att konsumeras.</p><p>Det finns två typer av absorptionskylmaskiner (ABS) tillgängliga på marknaden, antingen har de fjärrvärme eller ånga som drivmedel. Den typ av ABS som drivs av fjärrvärme lämpar sig för produktion av komfortkyla, dvs. kyla som inte behöver komma ned till så låga temperaturer. Ångdriven ABS kan däremot komma ned till lägre temperaturer, något som kan passa vid processkyla. En förutsättning för absorptionskyla är tillgång till billig värme/ånga. Tekniska Verken har tack vare avfallsförbränning tillgång till billig värme. Ångan i systemet produceras däremot idag med olja och el, något som gör det dyrare att generera absorptionskyla med hjälp av ånga.</p><p>En fallstudie utfördes på de två industrierna Linköpingsmejeriet och Swedish Meats där anslutningsmöjligheterna för absorptionskyla undersöktes. Främst behovet av processkyla har undersökts då det var betydligt större än behovet av komfortkyla. Ett antal fall med olika förutsättningar för att tillgodose dessa kylbehov till de båda industrierna har simulerats i MODEST. Utifrån de resultat som erhållits har följande slutsatser dragits.</p><p>• I dagsläget finns inte tillräckligt med ångproduktion i systemet för att tillgodose både det befintliga ångbehovet samt den mängd ånga som behövs för att framställa kylan.</p><p>• En investering i nya biopannor till ett kraftvärmeverk kan ge tillräcklig mängd billig ånga och värme för att ge lönsamhet i värmedriven kylproduktion.</p><p>• Koldioxidutsläppen, lokala såväl som globala, minskar som en följd av övergång från el-kompressorer till absorptionskylmaskiner. En investering i nya biopannor skulle minska utsläppen ytterligare, då fossilt bränsle ersätts.</p><p>• En investering i en litiumbromid absorptionskylmaskin är inte lönsam vid en så pass liten efterfråga som har varit aktuellt i de undersökta fallen.</p> / <p>The main purpose of this thesis has been to look in to the potential of a production of district cooling using heat as the source of power, i.e. absorptions cooling, in the energy system of Linköping. In the light of the fact that many energy companies are looking for new markets for district heating due to the surplus of heat in the summertime in an energy system with CHP (Combined Heat and Power). Furthermore, the price on electricity is expected to continue to rise since Sweden is most likely to follow Europe’s lead and embrace a power dimensioned energy system. As a result of that transition, energy efficient measures will be more important and absorption cooling implies that more electricity can be produced, instead of consumed, in a CHP system.</p><p>There are two different types of absorption cooling machines available in the market, with either district heating or steam as the source of power. A machine using district heating as the source of power is most suitable to produce comfort cooling i.e. the cold does not need to attain such low temperatures. A steam driven absorption cooling machine is able to attain the very low temperatures needed for cooling used in the processing industry. A condition for absorption cooling is the access to low-cost heat/steam. Tekniska Verken (an energy company) has due to waste incineration access to low-cost heat. The steam in the energy system is produced with oil and electricity, which makes it more expensive to generate absorption cooling with steam as the power source.</p><p>A casestudy was preformed at two industries in Linköping, Linköpingsmejeriet and Swedish Meats, where the possibility for connection of district cooling was examined. Mainly the cooling needed in the processing industry has been examined as this is need is considerably larger than the need for comfort cooling. A number of cases with different conditions for producing district cooling have been simulated in MODEST. The following conclusions have been drawn based on the results of the simulations.</p><p>• In the energy system of today there is not enough steam production to fulfil both the current need for steam and the amount of steam needed for cooling production.</p><p>• An investment in new CHP-plants using biomass fuels will generate enough heat and steam to be profitable for cooling production using heat as a source of power.</p><p>• The emission of carbon dioxide will decrease as a result of the transmission from compression cooling to absorption cooling. The emission will decrease further if an investment in new CHP plants with biomass fuels is carried out. This will then replace the use of fossil fuels.</p><p>• An investment in lithium bromide absorptions cooler will not be profitable with such a small demand as the one in question.</p>

<p>Desiccant cooling is a technology that, based on a open psychrometric cycle, is able to provide cooling using heat as the main energy carrier. This technology uses a considerably smaller amount of electricity than refrigerators based on the vapor-compression cycle, which is an electricity driven cycle. Electricity is often more expensive than other types of energy and has CO₂ emissions associated with its generation , so desiccant cooling has the potential of achieving both economic and environmental benefits.</p><p>In addition to this, the heat the desiccant cooling cycle needs to work can be supplied at relative low temperatures, so it can use heat coming from the district heating grid, from a solar collector or even waste heat coming from industries.</p><p>The system which will be studied in this report is a desiccant cooling system based on the model designed by the company Munters AB. The systems relies on several components: a desiccant rotor, a rotary heat exchanger two evaporative humidifiers and two heating coils. It is a flexible system that is able to provide cooling in summer and heat during winter.</p><p>This study performs a deep economic and environmental analysis of the desiccant cooling systems, comparing it with traditional vapor compression based systems:</p><p>In order to achieve this objective a user-friendly software was created, called the DCSS – Desiccant Cooling Simulation Software – that simulates the operation of the system during a year and performs automatically all the necessary calculations.</p><p>This study demonstrates that economic savings up to 54% percent can be achieved in the running costs of desiccant cooling systems when compared to traditional compressor cooling systems, and  reductions up to39% in the CO₂ emissions. It also demonstrates that desiccant cooling is more appropriate in dry climate zones with low latent heat generation gains.</p><p>In addition to that, the DSCC software created will help further studies about the physical, economic and environmental feasibility of installing desiccant cooling systems in different locations.</p>

Situationer där polisen skjuter kan uppstå till följd av att gärningsmän uppvisar provokativa suicidbeteenden. Detta fenomen är känt som suicide by cop (SbC) och har visat sig utgöra en betydande andel av undersökta skjuthändelser i Nordamerika. Studien syftar till att ge en deskriptiv bild av SbC i Sverige utifrån förekomst och karakteristika gällande situationer och gärningsmän, samt att beskriva hur dessa händelser kan upplevas och hanteras av poliser. Skjuthändelser som inträffat under tidsperioden 2005-2009 granskades och intervjuer genomfördes med tio poliser som upplevt SbC-händelser. Resultatet visade att SbC svarade för 26 % av skjuthändelserna. Intervjuade poliser upplevde ofta gärningsmännen som både aggressiva och suicidala och en osäkerhet över vem som egentligen haft kontroll över situationen var att betrakta som en central problematik. Vidare beskrevs akuta stressreaktioner och posttraumatiska minnen till följd av dessa händelser. Ökad kunskap om psykologin bakom SbC är att betrakta som viktigt för hanteringen av dessa incidenter. / Officer-involved shootings (OIS) sometimes occur as a result of provocative and suicidal behavior among offenders. This phenomenon, known as suicide by cop (SbC), has been shown to represent a significant part of OIS-cases in North American samples. This study aims to provide a descriptive picture of SbC in Sweden based on frequency and characteristics of situations and offenders. It also aims to describe how SbC can be experienced and handled by police officers. OIS-cases that occurred during 2005-2009 were investigated and ten officers were interviewed. Results showed that SbC accounted for 26 % of the OIS-cases. Interviewed officers often perceived perpetrators as both aggressive and suicidal and an uncertainty over who actually had control was considered a key issue. Officers also reported acute stress reactions and posttraumatic memories as a result of SbC. Increased knowledge about the psychology of SbC is considered as an important factor for dealing with SbC-situations.

The Achilles heel of the heat pump technology has for long been the low efficiency occurring during domestic hot water production. The problem is the high condensation pressure needed to reach high temperatures. To produce domestic hot water, the system need to deliver a supply temperature of about 60 °C, to be compared with a supply temperature of around 30-50 °C when heat is delivered to a radiator circuit. This drawback has for long held the heat pump technology back and instead gave room for alternative technologies on the market, like district heating.The Energy Machine is a heat pump system developed to bypass the poor efficiency during domestic hot water heating. The technology is based on the use of two heat pumps working together. The main heat pump delivers heat to the heating system, as usual, whilst the second smaller heat pump heats the domestic hot water. As the second heat pump is fed with reject heat from a subcooler in the main heat pump, it can operate at high efficiency, even when producing domestic hot water.The aim of this master thesis has been to investigate how the performance of the Energy Machine differs from that of a conventional heat pump system. In order to do so, models describing the two systems have been designed using MATLAB, Simulink. Simulations have then been performed to investigate how the two systems perform on an annual basis.The results of the simulations show that the Energy Machine performs much better than the conventional systems at most operating conditions, especially during domestic hot water heating. The annual COP- factor of the Energy Machine has proven to be 33,5 % higher than that of a conventional heat pump system. / Värmepumpsteknikens akilleshäl har sedan lång tid tillbaka varit den låga verkningsgraden som uppstår vid tappvarmvattenproduktion. Problemet är att det krävs mycket högt kondenseringstryck för att uppnå den höga framledningstemperatur som efterfrågas vid tappvarmvattenproduktion. Normalt krävs en temperatur omkring 60 °C vid tappvarmvattenproduktion, att jämföras med 30-50 °C då värme levereras ut på en radiatorkrets. Detta problem har länge hållt värmepumpstekninken tillbaka och istället givit utrymme för alternativ teknik på marknaden, såsom fjärrvärme.Energimaskinen, eller Energy Machine, är ett värmepumpssystem utvecklat för att kringgå problemet med den låga verkningsgraden vid tappvarmvattenproduktion. Tekniken bygger på två värmepumpar som arbetar tillsammans. En basmaskin används för att leverera värme ut på värmesystemet, medan en mindre värmepump används för att producera tappvarmvatten. Den mindre värmepumpen matas med värme från en underkylare i basmaskinen, vilket ger hög förångningstemperatur och därmed hög COP faktor, även vid tappvarmvattenproduktion.Målet med projektet har varit att jämföra prestandan hos en Energy Machine med ett konventionellt värmepumpssystem. För att kunna göra dettta har två modeller designats, en modell som beskriver en Energy Machine och en modell som beskriver ett konventionellt värmepumpssystem. Modellerna gjordes i MATLAB, Simulink, och simuleringar utfördes varpå resultaten tolkades och jämfördes.Resultaten från simuleringarna visar att en Energy Machine presterar mycket bättre än ett konventionellt värmepumpssystem i de allra flesta driftfallen , men särskilt vid tappvarmvattenproduktion. Simuleringarna visar att COP- faktorn på årsbasis för en Energy Machine är 33,5 % högre än den för ett konventionellt värmepumpssystem.

Desiccant cooling is a technology that, based on a open psychrometric cycle, is able to provide cooling using heat as the main energy carrier. This technology uses a considerably smaller amount of electricity than refrigerators based on the vapor-compression cycle, which is an electricity driven cycle. Electricity is often more expensive than other types of energy and has CO2 emissions associated with its generation , so desiccant cooling has the potential of achieving both economic and environmental benefits. In addition to this, the heat the desiccant cooling cycle needs to work can be supplied at relative low temperatures, so it can use heat coming from the district heating grid, from a solar collector or even waste heat coming from industries. The system which will be studied in this report is a desiccant cooling system based on the model designed by the company Munters AB. The systems relies on several components: a desiccant rotor, a rotary heat exchanger two evaporative humidifiers and two heating coils. It is a flexible system that is able to provide cooling in summer and heat during winter. This study performs a deep economic and environmental analysis of the desiccant cooling systems, comparing it with traditional vapor compression based systems: In order to achieve this objective a user-friendly software was created, called the DCSS – Desiccant Cooling Simulation Software – that simulates the operation of the system during a year and performs automatically all the necessary calculations. This study demonstrates that economic savings up to 54% percent can be achieved in the running costs of desiccant cooling systems when compared to traditional compressor cooling systems, and  reductions up to39% in the CO2 emissions. It also demonstrates that desiccant cooling is more appropriate in dry climate zones with low latent heat generation gains. In addition to that, the DSCC software created will help further studies about the physical, economic and environmental feasibility of installing desiccant cooling systems in different locations.

In this thesis, one of the current control algorithms for the R744 cycle, which tries tooptimize the performance of the system by two SISO control loops, is compared to acost-effective system with just one actuator. The operation of a key component of thissystem, a two stage orifice expansion valve is examined in a range of typical climateconditions. One alternative control loop for this system, which has been proposed byBehr group, is also scrutinized.The simulation results affirm the preference of using two control-loops instead of oneloop, but refute advantages of the Behr alternate control approach against one-loopcontrol. As far as the economic considerations of the A/C unit are concerned, usinga two-stage orifice expansion valve is desired by the automotive industry, thus basedon the experiment results, an improved logic for control of this system is proposed.In the second part, it is investigated whether the one-actuator control approach isapplicable to a system consisting of two parallel evaporators to allow passengers tocontrol different climate zones. The simulation results show that in the case of usinga two-stage orifice valve for the front evaporator and a fixed expansion valve forthe rear one, a proper distribution of the cooling power between the front and rearcompartment is possible for a broad range of climate conditions.

Huvudsyftet med arbetet har varit att undersöka potentialen för värmedriven kylproduktion, dvs. absorptionskyla, i Linköpings energisystem. Bakgrunden är att många energibolag söker efter nya avsättningsområden för fjärrvärme pga. det överskott på värme som finns sommartid i energisystem med kraftvärme. Dessutom förväntas elpriserna fortsätta stiga då Sverige med stor sannolikhet kommer att följa resten av Europa och gå från ett energidimensionerat system till ett effektdimensionerat system. Till följd av detta blir energieffektiviserande åtgärder allt viktigare och absorptionskyla innebär att mer el kan produceras i ett system med kraftvärme, istället för att konsumeras. Det finns två typer av absorptionskylmaskiner (ABS) tillgängliga på marknaden, antingen har de fjärrvärme eller ånga som drivmedel. Den typ av ABS som drivs av fjärrvärme lämpar sig för produktion av komfortkyla, dvs. kyla som inte behöver komma ned till så låga temperaturer. Ångdriven ABS kan däremot komma ned till lägre temperaturer, något som kan passa vid processkyla. En förutsättning för absorptionskyla är tillgång till billig värme/ånga. Tekniska Verken har tack vare avfallsförbränning tillgång till billig värme. Ångan i systemet produceras däremot idag med olja och el, något som gör det dyrare att generera absorptionskyla med hjälp av ånga. En fallstudie utfördes på de två industrierna Linköpingsmejeriet och Swedish Meats där anslutningsmöjligheterna för absorptionskyla undersöktes. Främst behovet av processkyla har undersökts då det var betydligt större än behovet av komfortkyla. Ett antal fall med olika förutsättningar för att tillgodose dessa kylbehov till de båda industrierna har simulerats i MODEST. Utifrån de resultat som erhållits har följande slutsatser dragits. • I dagsläget finns inte tillräckligt med ångproduktion i systemet för att tillgodose både det befintliga ångbehovet samt den mängd ånga som behövs för att framställa kylan. • En investering i nya biopannor till ett kraftvärmeverk kan ge tillräcklig mängd billig ånga och värme för att ge lönsamhet i värmedriven kylproduktion. • Koldioxidutsläppen, lokala såväl som globala, minskar som en följd av övergång från el-kompressorer till absorptionskylmaskiner. En investering i nya biopannor skulle minska utsläppen ytterligare, då fossilt bränsle ersätts. • En investering i en litiumbromid absorptionskylmaskin är inte lönsam vid en så pass liten efterfråga som har varit aktuellt i de undersökta fallen. / The main purpose of this thesis has been to look in to the potential of a production of district cooling using heat as the source of power, i.e. absorptions cooling, in the energy system of Linköping. In the light of the fact that many energy companies are looking for new markets for district heating due to the surplus of heat in the summertime in an energy system with CHP (Combined Heat and Power). Furthermore, the price on electricity is expected to continue to rise since Sweden is most likely to follow Europe’s lead and embrace a power dimensioned energy system. As a result of that transition, energy efficient measures will be more important and absorption cooling implies that more electricity can be produced, instead of consumed, in a CHP system. There are two different types of absorption cooling machines available in the market, with either district heating or steam as the source of power. A machine using district heating as the source of power is most suitable to produce comfort cooling i.e. the cold does not need to attain such low temperatures. A steam driven absorption cooling machine is able to attain the very low temperatures needed for cooling used in the processing industry. A condition for absorption cooling is the access to low-cost heat/steam. Tekniska Verken (an energy company) has due to waste incineration access to low-cost heat. The steam in the energy system is produced with oil and electricity, which makes it more expensive to generate absorption cooling with steam as the power source. A casestudy was preformed at two industries in Linköping, Linköpingsmejeriet and Swedish Meats, where the possibility for connection of district cooling was examined. Mainly the cooling needed in the processing industry has been examined as this is need is considerably larger than the need for comfort cooling. A number of cases with different conditions for producing district cooling have been simulated in MODEST. The following conclusions have been drawn based on the results of the simulations. • In the energy system of today there is not enough steam production to fulfil both the current need for steam and the amount of steam needed for cooling production. • An investment in new CHP-plants using biomass fuels will generate enough heat and steam to be profitable for cooling production using heat as a source of power. • The emission of carbon dioxide will decrease as a result of the transmission from compression cooling to absorption cooling. The emission will decrease further if an investment in new CHP plants with biomass fuels is carried out. This will then replace the use of fossil fuels. • An investment in lithium bromide absorptions cooler will not be profitable with such a small demand as the one in question.

This thesis consists of two research problems in the air conditioning (A/C) area. For the first problem, the aim is to model and simulate a variable refrigerant flow (VRF) air conditioning system. The coefficient of performance (COP) for refrigeration or heat pump system is one of the critical parameters for designing an air conditioning system. The modeling of the system components for a VRF cycle under different cooling conditions using R-134a and R-22 as refrigerants was carried out. Calculations were performed by varying different parameters such as condenser and evaporator temperatures, and refrigerant type. The R-134a refrigerant shows a better performance when multiple evaporators are present. Part load performance evaluation was also done for both refrigerants. The simulation results compared reasonably well with available experimental data. In the second problem, the objective is to develop a mathematical model that covers the mass, energy, entropy, and exergy balances of a typical air conditioning system. The model examines how the exergy efficiency of an air conditioning system can be used to measure its performance, bypass configuration, and additional significant environmental factors that affect an A/C system's design. The effects of outside air parameters, room parameters, room sensible and latent heat loads, and dead state properties on exergy efficiency were investigated. The range of parameters covered included outside air temperature (To= 25-60oC) and relative humidity (RHo = 50-85%), sensible heat load (Qsen = 11.50-13.25 kW), latent heat load (Qlat = 3.00-4.75 kW), room air temperature (Tr= 18-25oC), and relative humidity (RHr= 30-44%), and outside-mixture air flow rate ratio (qo/qm = 0.21-0.71). Two novel dead state conditions were selected to further analyze their effects on the system. Present exergy results indicate that an A/C system is quite sensitive to air properties, sensible and latent cooling loads, and dead state conditions.

Canine Oral Papillomavirus (COPV) induces warts on the oral mucosa in domestic dogs and other canids. The canine oral papillomatosis (COP) is a well established animal model of mucosal papillomatosis. While the regression of a current infection is mediated by cellular immunity, humoral immunity does prevent reinfection. Question of the present study was, if unspecific stimulation of the immune system with the inducer of paramunity Baypamune® during the period of growth would have an influence on the course of canine oral papillomatosis. Clinical criteria for this purpose were period of growth, period of regression and the size and morphology of Papillomas at the end of growth. Additionally ALAT and ASAT were quantified in order to rule out deterioration of liver cells. PCV and leucocytes where monitored and a differentiation was performed. In a second part of the study, L1-antibodies and IFNg, TNF-a as well as IL-18 were determined by the Institute of Virology of the Faculty of Veterinary Medicine of the University of Leipzig. At the end of the study, biopsies of mucosa were taken for detection of viral genome. In a pre-study, three Labrador Retrievers at 14 weeks of age were challenged with 15 μl of virus suspension (40 μg of COPV-L1 Protein/ml) per site by scarification of oral mucosa. Papillomas developed at all challenged sites. These were removed during the period of growth and handed over to the Institute of Virology of the Faculty of Summary 70 Veterinary Medicine of the University of Leipzig for preparation of the suspension used in the main study. In the main study, 13 Labrador Retrievers at 14 weeks of age were challenged with 10 μl of virus suspension (40 μg of COPV-L1 Protein/ml) per site by scarification of three areas of the left oral mucosa. All animals developed at least at one site warts, totally 88 % of the challenged sites showed papillomas. 44 Days after infection, 12 dogs were divided into two groups which did not differ in time of incubation and size of the papillomas. Over a period of four weeks, one group received a total of five dosis of Baypamune®, the other group five dosis of placebo. There was no statistically significant difference between the groups regarding the period of growth, period of regression, size and morphology of the papillomas. The administration of Baypamune® during the period of growth had no effect on the clinical course of COP in this trial. However, time of application of the substances should be considered critically, since papillomas of five animals had been in regression before the first application of Baypamune® and placebo had taken place. No deterioration of liver cells could be ascertained. There was no difference between the groups regarding packed cell volume, white blood count and differentiation throughout the study. Parameters of unspecific immunity determined by the Institute of Virology, IFN-γ, TNF-a und IL-18, delivered no evaluable results. However, four animals of the placebogroup showed Papilloma-DNA in the Biopsies taken, but none of the animals, that received Baypamune®, being this a possible indicator for stimulation of cellular immunity. Anti-L1-Antibodies rose earlier in the Baypamune®group than in the placebogroup. In conclusion therapeutic efficacy of Baypamune® in dogs with present COP could not be shown in this trial, making future investigation necessary.

Sequence analysis of part of a large plasmid carried by Australian environmental isolate of Listeria monocytogenes strain DRDC8 has lead to identification of an islet of genes that encode proteins similar to copper binding and transport genes found in other Gram positive bacteria. Comparative sequence analysis showed that there are at least four genes (pCT0017, pCT0018, pCT0019 and ctpA) on this islet predicted to be involved in copper homeostasis. One of these, ctpA, is predicted to encode a P-type ATPase with a function analogous to CopA, a copper transporting gene in Enterococcus hirae. ORF pCT0017 is likely to be a CopY-like regulatory protein which could control the expression of ctpA. ORF pCT0019 is predicted to be a Cu²⁺ binding protein. In addition, two genes located downstream of the ctpA are predicted to encode a two component regulatory system region. The predicted function of ORF pCT0018 is not clear. A related chromosomal gene (cutR) is predicted to also encode a copper transporting P-type ATPase. To investigate the role of the protein encoded by pCT0018, the growth behavior of L. monocytogenes strain DRDC8, other strains carrying mutations within pCT0018, pCT0019, cutR and ctpA, as well as strains cured of the large plasmid, were grown under conditions of copper stress and starvation. The growth data showed that with the exception of strain DRDC8 and other strains carrying ctpA, most were unable to grow at higher copper concentration (>15 mM CuSO₄) and suggested that the copper homeostasis genes located on the large plasmid are associated with tolerance to high levels of copper. Strain DSE955PL, which carries a cutR mutation and is cured of the large plasmid, was the most sensitive (<5 mM CuSO₄). This indicated that proteins encoded by plasmid genes work synergistically to confer tolerance to copper. Of most interest was the fact that a pCT0018 mutant was more sensitive (<15 mM CuSO₄) to high levels of copper than the wild type parent DRDC8 (<20 mM CuSO₄). This suggested that ORF pCT0018 was necessary for copper tolerance. To investigate the effects of insertion mutations in pCT0017, pCT0018 and ctpA on copper uptake and export, the levels of copper accumulated by these strains was assessed using atomic absorption spectroscopy. A significant difference in copper accumulation among the bacteria strains was observed when either LEB or BHI media were used to culture the bacteria. This data suggested that the growth medium chemicals influence the levels of copper accumulated by cells. However, the effect of these media on bacteria growth rates during copper stress was not significant. Atomic absorption analysis of intracellular copper accumulation suggested that DSE955PL and DSE955 (a chromosome mutant) were able to accumulate copper (80 - 110 mg.gˉ¹ dry weight of cells), whereas DRDC8 and strains carrying mutations in pCT0018, ctpA, and strains cured of the large plasmid, were less able to accumulate copper (30 - 70 mg.gˉ¹ dry weight of cells). This data suggested that cutR may encode a copper export system and that ctpA is involved in copper uptake. To investigate the gene expression profile for pCT0018 under elevated copper, reverse transcriptase PCR was used to detect transcripts encoding pCT0017, pCT0018, pCT0019 and pCT0020 from RNA extracted from L. monocytogenes strain DRDC8 following culture at elevated levels of copper. Although transcripts for each of the target genes were detected, transcription was not responsive to copper, nor was the pattern of transcription consistent with that expected for a single operon. To directly determine whether the protein encoded by the pCT0018 open reading frame was able to bind copper, this gene was cloned in pET15b in frame with an N-terminal Histag and expressed in E. coli. The expressed protein was purified with a Ni-NTA column and shown to contain copper. Attempts to directly show that protein pCT0018 could bind copper by Cu-IMAC were unable to unequivocally show that the protein was immobilized on the column. Purified protein was used to raise a polyclonal antiserum in rabbit and the antiserum was used for Western analysis to test expression of pCT0018 by wild type L. monocytogenes DRDC8 and specific gene mutants. Although the antiserum bound to purified protein, it was not possible to demonstrate binding to native pCT0018 in cell lysates prepared from L. monocytogenes DRDC8. SDS-PAGE of cytoplasmic and cell envelope proteins isolated from L. monocytogenes strains was used to identify proteins expressed in response to copper stress and starvation. No significant differences in protein profiles for cytoplasmic protein were observed. However, copper-immobilized metal affinity chromatography (Cu-IMAC) showed that expression of a number of copper binding proteins were differentially expressed by DRDC8 following growth in copper stress and starvation conditions. Three of these proteins were selected for amino sequence analysis by MALDI-TOFF MS. Two were confirmed to be L. monocytogenes non-heme iron-binding ferritin and a thiol peroxidase, both of which bind copper. The other protein was similar to an unknown protein from L. monocytogenes. Interestingly, no proteins directly implicated with the copper homeostasis islet were identified. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1374407 / Thesis (M.Sc.) - University of Adelaide, School of Molecular and Biomedical Science, 2009