De negativa klimatförändringarna är 2000-talets stora moraliska dilemma. Transportsektorn bidrar idag med cirka 27 procent av världens alla utsläpp. Därmed kan det finnas ett stort utrymme för branschen att minska sina utsläpp och därmed sin miljöpåverkan. Syftet med denna studie är undersöka vad som motiverar företag att ta hänsyn till miljön i sina beslut, dagliga som långsiktiga strategiska beslut. Studien är genomförd med en kvalitativ ansats och data har samlats in genom semistrukturerade intervjuer med 8 företag. Samtliga företag är verksamma inom transport- och logistikbranschen. Studien visar att majoriteten av de undersökta företagen idag arbetar med att förbättra miljöprestandan, och en stor del av det miljöarbete som företag gör bottnar i en strävan efter ökad lönsamhet. Företagen förklär sina effektiviseringsåtgärder med en ”grön exteriör” som kommunicerar miljöarbetet. Flera av företagen väljer att addera miljöaspekten till sitt varumärke för att tillföra ett värde som kan ge dem fler ”affärer”. Vad som även visats är att ingen kund betalar mer för en högre miljöprestanda.

名古屋大学博士学位論文 学位の種類 : 博士(医学)(課程) 学位授与年月日:平成25年3月25日 水谷武史氏の博士論文として提出された

The high affinity sodium/glucose cotransporter (SGLT1) couples transport of Na+ and glucose. Investigation of the structure/function relationships of the sodium/glucose transporter (SGLT1) is crucial to understanding co-transporter mechanism. In the first project, we used cysteine-scanning mutagenesis and chemical modification by methanethiosulphonate (MTS) derivatives to test whether predicted TM IV participates in sugar binding. Charged and polar residues and glucose/galactose malabsorption (GGM) missense mutations in TM IV were replaced with cysteine. Mutants exhibited sufficient expression to be studied in detail using the two-electrode voltage-clamp method in Xenopus laevis oocytes and COS-7 cells. The results from mutants T156C and K157C suggest that TM IV participates in sugar interaction with SGLT1. This work has been published in Am J Physiol Cell Physiol 295 (1), C64-72, 2008. The crystal structure of Vibrio parahaemolyticus SGLT (vSGLT) was recently published (1) and showed discrepancy with the predicted topology of mammalian SGLT1 in the region surrounding transmembrane segments IV-V. Therefore, in the second project, we investigated the topology in this region, thirty-eight residues from I143 to A180 in the N-terminal half of rabbit SGLT1 were individually replaced with cysteine and then expressed in COS-7 cells or Xenopus laevis oocytes. Based on the results from biotinylation of mutants in intact COS-7 cells, MTSES accessibility of cysteine mutants expressed in COS-7 cells, effect of substrate on the accessibility of mutant T156C in TM IV expressed in COS-7 cells, and characterization of cysteine mutants in TM V expressed in Xenopus laevis oocytes, we suggest that the region including residues 143-180 forms part of the Na+- and sugar substrate-binding cavity. Our results also suggest that TM IV of mammalian SGLT1 extends from residue 143-171 and support the crystal structure of vSGLT. This work has been published in Biochem Biophys Res Commun 378 (1), 133-138, 2009 Previous studies established that mutant Q457C human SGLT1 retains full activity, and sugar translocation is abolished in mutant Q457R or in mutant Q457C following reaction with methanethiosulfonate derivatives, but Na+ and sugar binding remain intact. Therefore, in the third project, we explored the mechanism by which modulation of Q457 abolishes transport, Q457C and Q457R of rabbit SGLT1 expressed in Xenopus laevis oocytes were studied using chemical modification, the two-electrode voltage-clamp technique and computer model simulations. Our results suggest that glutamine 457, in addition to being involved in sugar binding, is a residue that is sensitive to conformational changes of the carrier. This work has been published in Biophysical Journal 96 (2), 748-760, 2009. Taken together our study along with previous biochemical characterization of SGLT1 and crystal structure of vSGLT, we propose a limited structural model that attempts to bring together the functions of substrate binding (Na+ and sugar), coupling, and translocation. We propose that both Na+ and sugar enter a hydrophilic cavity formed by multiple transmembrane helices from both N-terminal half of SGLT1 and C-terminal half of SGLT1, analogous to all of the known crystal structures of ion-coupled transporters (the Na+/leucine transporter, Na+/aspartate transporter and lactose permease). The functionally important residues in SGLT1 (T156 and K157 in TM 4, D454 and Q457 in TM 11) are close to sugar binding sites.

Multidrug resistance protein (MRP)1, a member of the ABCC branch of the ATP-binding cassette (ABC) superfamily of transporters, can confer resistance to a broad spectrum of chemotherapeutic agents. In addition to the core functional unit of ABC transporters that consists of two membrane spanning domains (MSD) and two nucleotide binding domains (NBD), MRP1 contains a third MSD (MSD0) resulting in the following arrangement: NH2-MSD-(MSD-NBD)2. In lieu of high-resolution structural information for MRP1, cysteine scanning mutagenesis (CSM) was applied to MRP1 and involves the development of a functional template devoid of cysteines into which paired cysteines can be introduced. Previous attempts to create a functional, cys-less template of MRP1 demonstrated that cysteines in MSD0 were structurally and functional important (1;2). However, given that MRP1 lacking MSD0 remains functional, a partially functional, cys-less MRP1 lacking this domain has been expressed in yeast (3-5). Given these results, with the ultimate goal of applying CSM to MRP1 in its entirety, we investigated the endogenous cysteines within MSD0 and co-expressed MRP1 half-molecules and validated these potential CSM templates by transport and ATP binding/hydrolysis assays. Mutation of cysteines within the core of MRP1 had detrimental effects on MRP1 transport activity and further mutation of cysteines by domain revealed that wild-type activity was retained in an MSD0-less MRP1 dual lacking cysteines in both NBDs. This construct was used for introduction of cysteines on juxtaposed faces of the NBD1:NBD2 heterodimer at positions 775 and 1329; comparable residues in the related Cystic Fibrosis Transmembrane Regulator (CFTR/ABCC7) have been suggested to be evolutionarily coupled and joined by a hydrogen bond, maintained in structures of related proteins (6). Unfortunately, functional assays revealed that introduction of cysteines at these positions greatly reduced transport activity of MRP1 and diminished trapping of nucleotide at both NBDs. Finally, alanine substitution of the seven cysteines in MSD0 was not without effect and cellular trafficking assays, co-expression studies and SDS-PAGE analysis suggested an altered conformation of this domain. In addition, a disulfide pair of Cys7 and Cys32 was suggested by these experiments in MSD0 and further supported by examination of these mutants in full-length MRP1. / Thesis (Master, Pathology & Molecular Medicine) -- Queen's University, 2009-02-17 12:51:38.13

Each year, the coffee machines at Ericsson in Kista produce around 100 tons of ground coffee waste. The companies Coor Service Management, Löfbergs Lila and Selecta are all responsible for different stages in the logistical chain in delivering coffee and, together with Ericsson, they want to increase their environmental benefit. The plan is to produce biogas through anaerobic digestion instead of incinerating the coffee waste in a heating plant. The results are to be presented as different business cases in which different biogas plants are compared with the reference case (heating plant), comparing costs and environmental impacts. There are two major environmental benefits from producing biogas; reduced carbon dioxide emissions from when fossile fule is replaced by carbon neutral biogas, and reduced emissions from returning digestate from the bio reactor to farmland instead of using industrial fertelizer. In order to determine the biogas potential in coffee waste, a couple of properties had to be determined in a laboratory. Properties such as the dry substance content, heating value, moisture content and ash content. The results show that 100 tons coffee waste could produce around 16 500 Nm3 biogas which would contain 163 MWh. The biogas reactor and upgrade plant both need energy gas to function and uses around 14 MWh of the produced gas. In the end, the resulting upgraded biogas contains 149 MWh energy. Such an amount of gas can replace 15,1 m3 of diesel and thus reduce carbon dioxide emissions by 39,4 ton. The emissions from running the reactor and upgrade plant, combined with methane leakage amounts to 4,8 ton carbon dioxide. All of the biogas plants that were examined returns digestate and nutrients to farmlands which reduces the need for industrial fertelizer. The production of fertelizer uses alot of energy, and by returning digestate a reduction of 58 GJ energy and 3 ton CO2 can be achieved. This is not the case with the heat plant which instead has to place some of its produced ashes in landfills. If the exergy content in the biogas is compared to that of the heat it shows that there is a point to making gas instead of incinerating the waste. The biogas has about 50 % higher exergy content than the heat has and therefore it is possible to utilize the substrate more efficiently. Transporting coffee waste from Ericsson to different biogas plants will result in increased carbon dioxide emissions. The three plants investigated in this thesis are Henriksdals sewage treatment plant, the Himmerfjärd plant and Uppsala biogas plant. For each plant, drivning distance, pre treatment requirements of the coffee waste, and related costs were determined. Using methods from the Network for transportation and enviroment, the emissions for each case were calculated. The results show that the Henriksdal case will increase carbon dioxide emissions by two tons per year, and the other cases will increase emissions by four tons. The result from combining laboratory work, simulations and calculations show that the case where Henriksdal recives the coffee waste will reduce carbon dioxide emissions by 15,1 ton at a cost of 72 000 kr per year. The case with the Himmerfjärd plant will reduce emissions by 13,8 ton at a cost of 74 000 kr per year. The final case with Uppsala biogas plant will reduce emissions by 13,7 ton at the cost of 107 000 kr per year. And thus there are environmental benefits from producing biogas from the coffee waste, but they do come at a cost.

The release of the neurotoxic alkaloid saxitoxin by cyanobacterial cells was previously thought to occur primarily after cell lysis, yet recent evidence also suggests active toxin export by membrane transporters. Transporter proteins associated with STX biosynthesis in Cylindrospermopsis raciborskii T3 (sxtF and sxtM) and Anabaena circinalis 131C (naDt) were predicted to be involved in the export of STX from cyanobacterial cells. The main aim of this project was to characterise the transporters associated with STX biosynthesis, by investigation of their genetic prevalence, functional substrates and specific regulation. An sxtM homologue was discovered in A. circinalis 131C, as part of an sxt cluster, and found to be uniquely associated with STX-producing strains. Bioinformatic and phylogenetic analysis showed that the translated sxt transporters clustered with the NorM prokaryotic MATE sub-family and membrane topology analysis predicted 12 membrane-spanning regions. To characterise the functional substrates of the putative STX-transporters, they were heterologously expressed in the antibiotic-sensitive E. coli strain KAM32. Expression of the sxt MATES complemented host sensitivity to the cationic fluroquinolone antibiotics, ciprofloxacin and ofloxacin. Disruption of gene homologues of naDt and the sxt MATE genes in Synechocystis sp. PCC6803 yielded mutant strains with increased sensitivity to the toxic organic cations, methyl viologen and acriflavine. Transcription of the putative STX transporters, and the putative STX biosynthesis gene sxtA, was studied in C. raciborskii T3 and A. circinalis 131C under alkali and Na+ stress. Alkali stress (pH 9) decreased total STX levels in A. circinalis 131C and was correlated with a down-regulation of the putative transport and biosynthetic genes. In C. raciborskii T3, alkali stress promoted higher extracellular but lower intracellular STX levels, which also correlated with large increases in transcription of the putative STX transport genes.

Thesis (doctoral)--Universität, Düsseldorf, 2000.

Konstanz, Univ., Diss., 2004.

Zugl.: Aachen, Techn. Hochsch., Diss., 2009

Universiẗat, Diss., 2007--Frankfurt (Main). / Zsfassung in dt. und engl. Sprache.