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Functional Investigations into the Recognition Memory Network, its Association with Genetic Polymorphisms and Implications for Disorders of Emotional MemoryDörfel, Denise 22 January 2010 (has links)
Recent research, that has been focused on recognition memory, has revealed that two processes contribute to recognition of previously encountered items: recollection and familiarity (Aggleton & Brown, 1999; Eichenbaum, 2006; Eichenbaum, Yonelinas, & Ranganath, 2007; Rugg & Yonelinas, 2003; Skinner & Fernandes, 2007; Squire, Stark, & Clark, 2004; Wixted, 2007a; Yonelinas, 2001a; Yonelinas, 2002). The findings of neural correlates of recollection and familiarity lead to the assumption that there are different brain regions activated in either process, but there are, to the best of my knowledge, no studies assessing how these brain regions are working together in a recollection or a familiarity network, respectively. Additionally, there are almost no studies to date, which directly searched for overlapping regions. Therefore, in study I of the current thesis, brain regions associated to both recognition processes are searched investigated. Additionally, a connectivity analysis will search for functional correlated brain activations that either build a recollection or a familiarity network.
It is undoubtable that the Brain Derived Neurotrophic Factor (BDNF) is strongly involved in synaptic plasticity in the hippocampus (Bramham & Messaoudi, 2005) and there is evidence that a genetic variant of this neurotrophin (BDNF 66Met) is related to poorer memory performance (Egan, et al., 2003). Therefore, in study II of the current thesis, the effect of BDNF Val66Met on recollection and familiarity performance and related brain activations is investigated.
Finally, one could summarize, that serotonin, like BDNF, is strongly involved in brain development and plasticity as well as in learning and memory processes (Vizi, 2008). More precisely, there is evidence for alterations in the structure of brain regions, which are known to be involved in emotional memory formation and retrieval, like amygdala and hippocampus (Frodl, et al., 2008; Munafo, Brown, & Hariri, 2008; Pezawas, et al., 2005). One study found an slight epistatic effect of BDNF and 5-HTTLPR on the grey matter volume of the amygdala (Pezawas, et al., 2008). Therefore, in study III, it is investigated if such an interaction effect could be substantiated for the amygdala and additionally revealed for the hippocampus.
The results of the current thesis allow further comprehension of recollection, hence episodic memory, and point to a special role of the BDNF in temporal and prefrontal brain regions. Additionally, the finding of an epistatic effect between BDNF and serotonin transporter function point to the need of analyzing interactions between genes and also between genes and environmental factors which reveals more information than the study of main effects alone.
In conclusion, analyzing behavioral and neural correlates of episodic memory reveal allowed insights in brain functions that may serve as guideline for future studies in clinical populations with memory deficits, including susceptibility factors such as good or bad environment, as well as promising gene variants that influence episodic memory.
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Combinatorial Anticancer Therapy Strategy Using a Pan-Class I Glucose Transporter Inhibitor with Chemotherapy and Target Drugs in vitro and in vivoBachmann, Lindsey 28 April 2022 (has links)
No description available.
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Effekten av olika logistiklösningar : En studie kring fördelar och nackdelar med tredjepartslogistik och inbärning till ett projekt i DalarnaAndersson, Julia, Liedström, Matilda January 2021 (has links)
Inom byggbranschen har man börjat sett fördelar med att titta mer på logistiken iolika byggprojekt. Många olika studier har utförts kring vilka lösningar som finnsoch hur man kan använda dem.Denna studie utförs i samarbete med Skanska Sverige AB. Studien syftar till att påolika sätt undersöka vilka fördelar och nackdelar man kan se med att använda sigav logistiktjänsterna terminalisering och inbärning till ett byggprojekt i Dalarna.Byggprojektet som utgör det specifika fallet i studien är ett ombyggnadsprojekt aven grundskola. Elever vistas i detta skolområde samtidigt som ombyggnationenutförs etappvis inom det stängda arbetsområdet. Studien innefattar även tredje mandär trygghetsupplevelse kring arbetsplatsen undersöks. Inbärningens användbarhetdiskuteras därefter utifrån trygghetsupplevelsen kring och inom arbetsplatsen samtutifrån ekonomiskt och ekologiskt perspektiv.Metoder som används i studien är intervjuer med somliga från projektets ledning,en logistiker på Skanska, rektor för årskurs F-6, yrkesarbetare samt tredje man.Utöver dessa intervjuer utförs även en fältstudie som involverar observationer ochmätningar. Som avslut utförs överslagsberäkningar för att se om användning av ettexternt företag kan leda till ekonomisk lönsamhet.Studiens resultat visar hur man inom företaget ser på logistiklösningarnaterminalisering och inbärning idag. Här visas även vilka fördelar och nackdelarolika parter ser med tjänsterna. Fältstudiens mätningar visar hur många av tredjeman som rör sig kring arbetsområdet i anslutning till att skoldagen börjar.Överslagsberäkningar visar på att man kan se en besparing ifall man använder sigav ett inbärningsföretag som arbetar under kvällstid och detta sker i samband medatt man använder sig av terminalisering.Studiens slutsatser är att det inte finns en allmän lösning till hur logistikfrågan skalösas på olika projekt. Om det finns möjlighet för terminalisering i området ärdetta samt inbärning ett alternativ för projektet. / Within the construction industry the advantages of looking at the logistics todifferent projects has been acknowledged during the past couple of years.This study has been written in collaboration with Skanska Sverige AB. Thepurpose of the study is to, in different ways, examine what advantages anddisadvantages there are in using the logistics solutions terminalization (also knownto be a part of Third Party Logistics) and inside delivery to a specific project inDalarna, Sweden. This project is a remodeling project of a school with studentsfrom six to sixteen years old. Within the school area new parts of the school isbuilt while students are located in the yet existent buildings. This infer thatstudents move around the construction sites daily. The study also involves thirdparty people and how these people feel about the large transports connected to theproject. The inside delivery utility is then discussed based on the securityexperience within and around the construction site along with the economic andecological perspective of the service.The methods used in this study are interviews with three people of the projectmanagement, one person that works with logistics at the company, the headmasterof the younger students, skilled workers and third party people. Furthermore afield study is done that includes measurements and observations. As a close,calculations are done to determine if a economical profitability could be possibleby using inside delivery.Results from the study show how the logistics solutions terminalization and insidedelivery is looked at within Skanska today. Here, the advantages anddisadvantages with the different services are displayed from the perspectives of thepeople who were interviewed. The results from the measurements from the fieldstudy presents how many third party people that move adjacent to the two activeconstruction sites when the school day begins. The calculations show that it iseconomically beneficial to use inside delivery after the end of the workday whileused with terminalization.Conclusions of the study indicate that there are no overall solutions regarding howthe logistics must be used in different projects. If there is a possibility to use terminalization in the area where the project is situated, this, along with insidedelivery, is a good alternative for the project.
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Metal Containing Nucleosides that Function as Therapeutic and Diagnostic Agents Against Brain CancerWilliams, Jennifer Nicole 02 September 2014 (has links)
No description available.
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Characterization of Amino Acid Transporters : Transporters expressed in the central nervous system belonging to the Solute Carrier family SLC38Hellsten, Sofie Victoria January 2016 (has links)
In cells and organelles transporters are responsible for translocation of amino acids, sugars and nucleotides among others. In the central nervous system (CNS), amino acid transporters can function as neurotransmitter transporters and nutrient sensors. The Solute carrier (SLC) superfamily is the largest family of transporters with 395 members divided in 52 families. The system A and system N amino acid transporter family, SLC38, consists of 11 members, SNAT1-11 (SLC38A1-11). The members are expressed in the brain, exclusively in neurons or astrocytes and some in both. Amino acid signaling is mainly regulated via two pathways, the amino acid responsive (AAR) pathway and the mechanistic/mammalian target of rapamycin complex 1 (mTORC1) pathway. These pathways regulate the protein synthesis in opposite directions depending on the amino acid availability. SLC38 members along with other SLCs have been identified to participate in these pathways. In paper I, the regulation of SLC genes after complete amino acid starvation in mouse hypothalamic cells have been studied with microarray and we found that 47 SLC genes were significantly altered at five hours of starvation. Interestingly, we found that Slc38a1 and Slc38a7 were upregulated along with the known starvation responding gene, Slc38a2. A complementary starvation study for the SLC38 genes was performed using primary mouse embryonic cortex cells. We found that Slc38a1, Slc38a2, Slc38a5, Slc38a6 and Slc38a8 were upregulated while Slc38a3, Slc38a7 and Slc38a11 were downregulated. Three members from the SLC38 family, SNAT8 (paper IV), SNAT9 (paper III) and SNAT10 (paper II) have been histologically characterized in mouse brain and all these transporters are exclusively neuronal. SNAT8 and SNAT10 were also functionally characterized and shown to be transporters for alanine and glutamine among others. SNAT8 was shown to mediate sodium dependent transport and was classified to system A. SNAT10 was shown to be a sodium independent bidirectional transporter and displayed characteristics for system A and N. SNAT9 is a lysosomal component of the Ragulator-Rag complex which senses amino acid availability and activates mTORC1. In paper III we also found that Slc38a9 gene expression was upregulated following starvation and downregulated following high-fat diet in mouse brain.
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Bio-crude transcriptomics: Gene discovery and metabolic network reconstruction for the biosynthesis of the terpenome of the hydrocarbon oil-producing green alga, Botryococcus braunii race B (Showa)*Molnar, Istvan, Lopez, David, Wisecaver, Jennifer, Devarenne, Timothy, Weiss, Taylor, Pellegrini, Matteo, Hackett, Jeremiah January 2012 (has links)
BACKGROUND:Microalgae hold promise for yielding a biofuel feedstock that is sustainable, carbon-neutral, distributed, and only minimally disruptive for the production of food and feed by traditional agriculture. Amongst oleaginous eukaryotic algae, the B race of Botryococcus braunii is unique in that it produces large amounts of liquid hydrocarbons of terpenoid origin. These are comparable to fossil crude oil, and are sequestered outside the cells in a communal extracellular polymeric matrix material. Biosynthetic engineering of terpenoid bio-crude production requires identification of genes and reconstruction of metabolic pathways responsible for production of both hydrocarbons and other metabolites of the alga that compete for photosynthetic carbon and energy.RESULTS:A de novo assembly of 1,334,609 next-generation pyrosequencing reads form the Showa strain of the B race of B. braunii yielded a transcriptomic database of 46,422 contigs with an average length of 756 bp. Contigs were annotated with pathway, ontology, and protein domain identifiers. Manual curation allowed the reconstruction of pathways that produce terpenoid liquid hydrocarbons from primary metabolites, and pathways that divert photosynthetic carbon into tetraterpenoid carotenoids, diterpenoids, and the prenyl chains of meroterpenoid quinones and chlorophyll. Inventories of machine-assembled contigs are also presented for reconstructed pathways for the biosynthesis of competing storage compounds including triacylglycerol and starch. Regeneration of S-adenosylmethionine, and the extracellular localization of the hydrocarbon oils by active transport and possibly autophagy are also investigated.CONCLUSIONS:The construction of an annotated transcriptomic database, publicly available in a web-based data depository and annotation tool, provides a foundation for metabolic pathway and network reconstruction, and facilitates further omics studies in the absence of a genome sequence for the Showa strain of B. braunii, race B. Further, the transcriptome database empowers future biosynthetic engineering approaches for strain improvement and the transfer of desirable traits to heterologous hosts.
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DIET-INDUCED OBESITY: DOPAMINERGIC AND BEHAVIORAL MECHANISMS AS OUTCOMES AND PREDICTORSNarayanaswami, Vidya 01 January 2013 (has links)
Obesity and drug abuse share common neural circuitries including the mesocoticolimbic and striatal dopamine reward system. In the current study, a rat model of diet-induced obesity (DIO) was used to determine striatal dopamine function, impulsivity and motivation as neurobehavioral outcomes and predictors of obesity. For the outcome study, rats were randomly assigned a high-fat (HF) or a low-fat (LF) diet for 8 wk. Following the 8-wk HF-diet exposure, rats were segregated into obesity-prone and obesity-resistant groups based on maximum and minimum body weight gain, respectively, and neurobehavioral outcomes were evaluated. For the predictor study, neurobehavioral antecedents were evaluated prior to an 8-wk high-fat diet exposure and were correlated with subsequent body weight gain. Striatal D2 receptor density was determined by in vitro kinetic analysis of [3H]raclopride binding. DAT function was determined using in vitro kinetic analysis of [3H]dopamine uptake, methamphetamine-evoked [3H]dopamine overflow and no net flux in vivo microdialysis. DAT cell-surface expression was determined using biotinylation and Western blotting. Impulsivity and food-motivated behavior were determined using a delay discounting task and progressive ratio schedule for food-reinforcers, respectively. Relative to obesity-resistant, obesity-prone rats exhibited 18% greater body weight, 42% lower striatal D2 receptor density, 30% lower total DAT expression, 40% lower in vitro and in vivo DAT function, 45% greater extracellular dopamine concentration, and 2-fold greater methamphetamine-evoked [3H]dopamine overflow. Obesity-prone rats exhibited higher motivation for food, but were less impulsive relative to obesity-resistant rats. Neurobehavioral antecedents of DIO included greater motivation for high-fat reinforcers in rats subsequently shown to be obesity-prone relative to obesity-resistant. Impulsivity, DAT function and extracellular dopamine concentration did not predict the DIO-phenotype. Thus, motivation for food is linked to both initiation and maintenance of obesity. Importantly, obesity results in decreased striatal DAT function, which may underlie the maintenance of compulsive food intake in obesity.
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Structure and function of nitrate and nitrite transporters, NrtA and NitA, from Aspergillus nidulansSymington, Vicki F. January 2009 (has links)
Membrane proteins play an integral role in the control of ion transport across the cell membrane in biological systems. However, due to experimental constraints, structural and functional data available for these proteins is limited, especially considering their importance. In this study, two membrane proteins which transport nitrate and nitrate into the model filamentous ascomycete Aspergillus nidulans were investigated. Work on the twelve trans-membrane domain nitrate transport protein NrtA is well established. As a member of the major facilitator super family (MFS) the role of signature sequences characteristic of this family have previously been studied. Here, a series of point mutations were made to facilitate an understanding of key residues in the nitrate binding domain, the first nitrate signature motif and residues of the unique fungal central-loop domain. Using an expanded alignment package, the proposed secondary structure of NrtA was enhanced and used as a starting point for mutagenesis. Alanine scanning mutagenesis showed that glycine residues in the conserved nitrate nitrite porter (NNP) motif were critical for NrtA function. Two asparagines in the NNP were investigated; N160 and N168. N168 was found to be critical for NrtA function as all mutants were devoid of growth on nitrate solid agar medium though they expressed in the membrane to varying degrees. The nitrate binding site has been studied previously, revealing the interaction of conserved arginine residues with the anion as it traverses the bilayer. Though it was thought that mutations of residue T83 to a small, charge neutral, amino acid would substitute for no alteration to enzyme kinetics in mutant T83S was found when using ¹³NO₃⁻. Another major part of this thesis examined NitA which is part of a distinct nitrite transport family to NrtA (the Formate Nitrite Transporters, FNT). A mutagenesis approach targeted NitA residues conserved amongst homologous proteins. Residues in position D88 in an alignment of homologues were conserved in terms of charge. Mutagenesis of D88 revealed that maintaining charge at this position was essential for NitA function, likely due to a role in salt-bridge formation during conformational changes. Mutations to asparagine, glutamine, serine and valine showed reduced growth on agar though the protein was expressed to approximately wild-type levels. Nitrite uptake assays using a ¹³NO₂⁻ tracer were performed on D88N, D88E and D88Q and all showed wild-type Km and Vmax. Finally, the role of conserved asparagine residues found throughout NitA was investigated by mutagenesis. Expression studies revealed that mutants created in N122 and N246, changed to aspartic acid, lysine, glutamine and serine were generally not present in the membrane and thus did not grow on nitrite agar. However, mutations in N173 (in Tm 4) and N214 (in Tm 5), which are conserved in > 95 % of NitA homologues, showed varying degrees of growth and expression. Both of these residues are located in FNT signature motifs, so it is likely that they are involved with conformational changes or protein dynamics.
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β-Adrenergic Signalling Through mTOROlsen, Jessica M. January 2017 (has links)
Adrenergic signalling is part of the sympathetic nervous system and is activated upon stimulation by the catecholamines epinephrine and norepinephrine. This regulates heart rate, energy mobilization, digestion and helps to divert blood flow to important organs. Insulin is released to regulate metabolism of carbohydrates, fats and proteins, mainly by taking up glucose from the blood. The insulin and the catecholamine hormone systems are normally working as opposing metabolic regulators and are therefore thought to antagonize each other. One of the major regulators involved in insulin signalling is the mechanistic target of rapamycin (mTOR). There are two different complexes of mTOR; mTORC1 and mTORC2, and they are essential in the control of cell growth, metabolism and energy homeostasis. Since mTOR is one of the major signalling nodes for anabolic actions of insulin it was thought that catecholamines might oppose this action by inhibiting the complexes. However, lately there are studies demonstrating that this may not be the case. mTOR is for instance part of the adrenergic signalling pathway resulting in hypertrophy of cardiac and skeletal muscle cells and inhibition of smooth muscle relaxation and helps to regulate browning in white adipose tissue and thermogenesis in brown adipose tissue (BAT). In this thesis I show that β-adrenergic signalling leading to glucose uptake occurs independently of insulin in skeletal muscle and BAT, and does not activate either Akt or mTORC1, but that the master regulator of this pathway is mTORC2. Further, my co-workers and I demonstrates that β-adrenergic stimulation in skeletal muscle and BAT utilizes different glucose transporters. In skeletal muscle, GLUT4 is translocated to the plasma membrane upon stimulation. However, in BAT, β-adrenergic stimulation results in glucose uptake through translocation of GLUT1. Importantly, in both skeletal muscle and BAT, the role of mTORC2 in β-adrenergic stimulated glucose uptake is to regulate GLUT-translocation. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.</p>
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Caracterisation physiologique et fonctionnelle du transporteur anionique ATCLC-C chez Arabidopsis Thaliana / Physiological and functional characterization of the anion transporter AtCLC-c in Arabidopsis thalianaKroniewicz, Laetitia 25 January 2011 (has links)
Chez les végétaux supérieurs, la régulation des mouvements stomatiques permet de contrôler les échanges de CO2 et la montée de la sève brute tout en limitant les pertes excessives d'eau par transpiration. Ce contrôle est assuré par des variations rapides de la turgescence des deux cellules de garde formant le stomate dues à l'activité de nombreux canaux et transporteurs ioniques. Nous avons identifié un nouveau membre de la famille des CLC chez A. thaliana, AtCLC-c exprimé dans la cellule de garde. L'étude de l'expression d'AtCLC-c et du phénotype de mutants invalidés ont permis de démontrer son rôle dans l'ouverture stomatique à la lumière et la fermeture en réponse à l'ABA. Les mutants clcc accumulent moins d'ions Cl- dans leurs cellules de garde par rapport aux plantes sauvages et sont hypersensibles à un stress salin. Enfin, nous avons confirmé par des études d'électrophysiologie la sélectivité d'AtCLC-c aux ions Cl-. L'ensemble de ce travail montre l'importance du transporteur vacuolaire d'ions Cl- AtCLC-c dans les mouvements stomatiques et la tolérance au stress salin. / In plants, the high turgor is assured by ion transport and involves the creation and maintenance of a large vacuolar volume. In recent years, various chloride channels and transporters have been identified to be involved in specific functions such as plant nutrition, stomatal movements or metal tolerance. We have characterized a new member of the CLC family in A. thaliana, AtCLC-c, highly expressed in guard cell and up-regulated by ABA and salt treatment in the whole plant. Knock-out mutants in AtCLC-c are impaired in light-induced stomatal opening and ABA-induced stomatal closing correlated to a large decrease in guard cell Cl- content. Furthermore, clcc mutants are hypersensitive to salt stress compared to wild-type. Finally, using electrophysiological studies, we demonstrated that AtCLC-c is selective to Cl-. Altogether, this work shows that AtCLC-c is a tonoplastic Cl- transporter involved in stomatal movements and salt tolerance.
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