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This thesis investigates the feasibility of producing activated carbon from polysaccharides. Activated carbons are high surface area solids with rich surface functionality and as a result, find use in a variety of industrial separation processes. The market for activated carbon is already established and growing but there is a huge push to find sustainable alternatives for the raw material used for its production, which is primarily coal. While there exists a significant amount of research on agricultural residues as potential replacements, there is minimal information on using polysaccharides as precursors for the production of activated carbon. Using the patented PGX process, two separate approaches were employed for the synthesis of activated carbon. The first method relied on the porous network of PGX materials to be maintained during pyrolysis while the second approach used a chemical agent to create porosity during the pyrolysis. Gas sorption analysis revealed that the PGX structure was not maintained during the pyrolysis stage hence losing all its pore network and extended surface area. Additionally, no significant variation between the PGX and non PGX variants of the chemically activated polymers was observed. However, it was revealed that the interaction between zinc chloride and pectin produced exceptionally high specific surface area (exceeding 2000 m2 g-1) activated carbon. The produced carbon had a high degree of microporosity (up to 100%) with some flexibility present in tuning the porosity. Elemental analysis revealed the carbon to have high surface functionality and preliminary adsorption test for removal of heavy metal ions from water (Pb2+ and Cd2+) showed promising results with the in-house carbon performing better than a representative commercial carbon. This study relies on statistical methods including multiple design of experiment studies and advanced characterization techniques to analyze the manufacturing process and the properties of carbon in an attempt to find the best conditions for producing activated carbon from polysaccharides. / Thesis / Master of Applied Science (MASc)

Objective - To evaluate a surgical technique for performing laparoscopic bilateral ovariectomy in standing horses. Study Design - Experimental study. Animals or Sample population - 8 mares, age 2-20 years, weight 410-540 kg. Methods - Standing laparoscopic bilateral ovariectomy was performed in 8 mares with normal anatomy of the reproductive tract. The Harmonic Scalpel (an ultrasonically activated instrument) was used to transect the ovarian pedicle and to obtain hemostasis simultaneously. Necropsy was performed on 4 mares 3 days after surgery and 30 days following surgery on the remaining 4 mares. Gross and histopathologic evaluation of the ovarian pedicles was performed to characterize the effects of the Harmonic Scalpel on the transected tissue. Results - The Harmonic Scalpel achieved complete hemostasis of the vasculature of the ovarian pedicles in all mares. Median transection time for the ovarian pedicle was 28 minutes. Postoperative complications included transient fever in one mare, moderate subcutaneous emphysema in another, and incisional seroma formation in a third mare. Post-mortem examination 3 and 30 days postoperatively revealed no signs of generalized peritonitis, postoperative hemorrhage or adhesion formation. Mild to moderate acute inflammation, and scar formation with moderate chronic inflammation at the ovarian pedicle was found 3 and 30 days after surgery, respectively. Median depth of coagulation necrosis 3 days postoperatively was 2.87 mm. Conclusions - The Harmonic Scalpel appears to provide reliable hemostasis of the ovarian pedicle during elective laparoscopic ovariectomy in horses. Clinical Relevance - The Harmonic Scalpel represents a safe alternative to other means of hemostasis during elective laparoscopic ovariectomy in horses. / Master of Science

No / Cryptolepine, an indoloquinoline alkaloid in Cryptolepis sanguinolenta, has anti-inflammatory property. In this study, we aimed to evaluate the effects of cryptolepine on lipopolysaccharide (LPS)- induced neuroinflammation in rat microglia and its potential mechanisms. Microglial activation was induced by stimulation with LPS, and the effects of cryptolepine pretreatment on microglial activation and production of proinflammatory mediators, PGE2/COX-2, microsomal prostaglandin E2 synthase and nitric oxide/iNOS were investigated. We further elucidated the role of Nuclear Factor-kappa B (NF-κB) and the mitogen-activated protein kinases in the antiinflammatory actions of cryptolepine in LPS-stimulated microglia. Our results showed that cryptolepine significantly inhibited LPS-induced production of tumour necrosis factor-alpha (TNFα), interleukin-6 (IL-6), interleukin-1beta (IL-1β), nitric oxide, and PGE2. Protein and mRNA levels of COX-2 and iNOS were also attenuated by cryptolepine. Further experiments on intracellular signalling mechanisms show that IκB-independent inhibition of NF-κB nuclear translocation contributes to the anti-neuroinflammatory actions of cryptolepine. Results also show that cryptolepine inhibited LPS-induced p38 and MAPKAPK2 phosphorylation in the microglia. Cell viability experiments revealed that cryptolepine (2.5 and 5 μM) did not produce cytotoxicity in microglia. Taken together, our results suggest that cryptolepine inhibits LPS-induced microglial inflammation by partial targeting of NF-κB signalling and attenuation of p38/MAPKAPK2.

Yes / Inflammation of adipose tissue in obesity is associated with increased IL-1β, IL-6 and TNF-α secretion and proposed to contribute to insulin resistance. AMP-activated protein kinase (AMPK) regulates nutrient metabolism and is reported to have anti-inflammatory actions in adipose tissue, yet the mechanisms underlying this remain poorly characterised. The effect of AMPK activation on cytokine-stimulated proinflammatory signalling was therefore assessed in cultured adipocytes. AMPK activation inhibited IL-1β-stimulated CXCL10 secretion, associated with reduced interleukin-1 receptor associated kinase-4 (IRAK4) phosphorylation and downregulated MKK4/JNK and IKK/IκB/NFκB signalling. AMPK activation inhibited TNF-α-stimulated IKK/IκB/NFκB signalling but had no effect on JNK phosphorylation. The JAK/STAT3 pathway was also suppressed by AMPK after IL-6 stimulation and during adipogenesis. Adipose tissue from AMPKα1−/− mice exhibited increased JNK and STAT3 phosphorylation, supporting suppression of these distinct proinflammatory pathways by AMPK in vivo. The inhibition of multiple pro-inflammatory signalling pathways by AMPK may underlie the reported beneficial effects of AMPK activation in adipose tissue. / British Heart Foundation

A collaborative pilot study of the microflora on biological activated charcoal (BAC) filters employed in the tertiary treatment of drinking water revealed the principle bacterial genera to be Pseudomonas, Alcaligenes, Achromobacter, Bacillus, Micrococcus, Corynebacterium, Chromobacterium, Microcyclus and Paracoccus. The microbial population of the filters paralleled seasonal carbon dioxide production. Of particular interest were the effects of the BAC miroorganisms upon precursors of trihalomethanes (THMs). Mixed populations of BAC microorganisms were cultivated for 50 days in a mineral salts-humic acid medium. It was concluded that (1) the BAC microflora enhances the absorptive capacity of the filters; (2) chemico-physical and biological processes operate in concert to lower the concentration of precursors of THMs; and (3) few bacterial pathogens establish themselves on the filters.

Call number: LD2668 .T4 1986 K86 / Master of Science / Civil Engineering

5 mutations responsables de retard mental ont été identifiées dans le gène p21-activated kinase 3 (pak3). Nous avons récemment identifiés dans pak3 deux exons alternatifs très conservés appelés b et c. Ainsi, en plus du variants PAK3a (dépourvu des inserts b ou c), le gène pak3 code pour 3 nouveaux variants d’épissage PAK3b, PAK3c et PAK3cb qui sont constitutivement actifs et insensibles aux GTPases. De plus, contrairement à PAK1 et PAK3a, leur domaine d’auto-inhibition est incapable d’inhiber un domaine kinase. Ainsi, le but de ce projet était de comprendre le mécanisme de régulation de la kinase PAK3. Un modèle de régulation a récemment été proposé dans lequel PAK1 forme des homodimères pouvant être dissociés par les GTPases, permettant ainsi l’activation de la kinase. En se basant sur ces observations j’ai cherché à identifier les dimères PAK3 et j’ai montré que les kinases PAK3a, b, c et cb forment préférentiellement des hétérodimères avec PAK1. J’ai démontré l’existence de ces dimères dans le cerveau et j’ai mis en évidence que ces hétérodimères permettent à chaque monomère de réguler l’activité kinase de son partenaire in vitro. Ce travail permet de proposer un modèle de régulation symétrique pour PAK3a qui forme des hétérodimères avec PAK1 et un nouveau modèle de régulation asymétrique pour les variants d’épissage, également basé sur leur hétérodimérisation avec PAK1. Mes résultats montrant une corégulation des kinases PAK neuronales suggèrent d'une part que leur activation puisse être synchronisée et d'autre part que dans certaines situations physiopathologiques (Cancer et maladies neurologiques) leur dérèglement puissent interférer. / 5 mutations responsible for mental retardation have been identified in p21-activated kinase 3 (pak3) gene. We recently identified in pak3, two highly conserved alternative exons called b and c. In addition to the classical PAK3a variant (without any alternative exon), the pak3 gene encodes 3 new splice variants PAK3b, PAK3c and PAK3cb which are constitutively active and insensitive to GTPase activation. Moreover, unlike PAK1 or PAK3a, their autoinhibitory domain is unable to inhibit a kinase domain. The aim of this project was to understand how PAK3 regulation occurs. A model of regulation was recently proposed in which PAK1 forms homodimers that can be dissociated through GTPase binding, leading to kinase activation. Given these observations, I searched to identify PAK3 dimers and I showed that PAK3a, b, c and cb preferentially form heterodimers with PAK1. I demonstrated the existence of such dimers in the brain and that the different heterodimers allow each monomer to regulate the kinase activity of its partner. Through this study, I propose a symmetric regulation model for PAK3a which heterodimerizes with PAK1 and a new asymmetric regulation model for splice variants, also based on heterodimerization with PAK1. My results showing a co-regulation of neuronal PAK kinases suggest that their activation may be synchronized but also that, in some physiopathological situations (cancers and neurologic diseases), their misregulation may interfere.

For centuries, researchers have been trying to achieve precise control and tailor materials properties. Several approaches, i.e., thermo-activation, electro-activation, and photo-activation, have been widely utilized. As an alternate and fundamentally different approach, mechano-activation is still relatively less-known. In particular, understanding the roles of mechano-activated electronic and molecular structures is yet to be achieved. This research contributes the fundamental understanding in mechanisms of mechano-activation and its effects on materials properties. Experimental investigation and theoretical analysis were involved in the present research. A methodology was developed to introduce the mechnao-activation and to study its subsequent effects. There are three major areas of investigation involved. First, the means to introduce mechanoactivation, such as energetic particle collision or a bending deformation (tensile force); Second, in-situ and ex-situ characterization using AFM, FTIR, UV-Vis, and XPS etc. techniques; Third, theoretical analysis through modified Lennard-Jones potentials in order to explain the behavior of materials under mechano-activation. In the present research, experiments on a Diamond-Like Carbon (DLC) film, a Polyvinylidene Fluoride (PVDF) film, and the Silver-Crown Ether nanochains (Ag-NCs) were carried out. For DLC, the collision-induced transformation between hybridization states of carbon was confirmed, which also dominated the friction behavior of the film. For PVDF, results show that the applied tensile force induced the transformation of [alpha], [beta], and [upsilon] crystalline phase. In addition, the transformation observed was time and direction dependent. For Ag-NCs, a new approach based on the mechanism of mechano-activation was developed for nanochain structure synthesis. Molecular dynamics simulation and experimental results revealed that the formation of Ag-NCs is a synergetic physicalchemical procedure. Experimental results from DLC and PVDF were further used to validate the proposed potential, which brought new insight into the activation process. The current research achieves a precise control on engineering materials properties. The force-activated materials have wide applications in many areas, such as functional coating, sensing, and catalysis. In this study selected experiments have demonstrated the effects of mechanoactivation in different material systems (ceramic, polymer, metallic nano structure) and at different length scales. For the first time, a modified potential was proposed to explain the observed mechano-activation phenomena from the energy point of view. It was validated by experimental results of DLC and PVDF. The current research brings new understanding in mechano-activation and opens potential for its applications in tailoring materials properties.

<p>Analytical analyses conducted at the Himmerfjärden WWTP (285.000 PE connected) identified 70 pharmaceutical compounds belonging to different therapeutic classes. Such organic micropollutants at low detected concentration range of µg - ng l^-1 did not affect the treatment processes at WWTP. Results from analytical studies indicated continuous discharge of organic micropollutants to the surface water with a calculated load amounting to 1.51 kg day-1. Metoprolol, carbamazepine and naproxen were chosen for testing different removal methods. Oxygen Uptake Rate (OUR) tests were conducted to assess the bacterial activity of an activated sludge taken from a full scale aeration plant with the presence of selected target compounds.</p><p>A semi-technical scale membrane bioreactor ZeeWeed10™, treating final effluent from the Himmerfjärden WWTP (Sweden) was seeded with activated sludge from full scale biological stage. The membrane bioreactor (MBR) system placed after the final treatment appeared to be an insufficient technology for removal of residual amounts of organic micropollutants from WWTP effluents. Batch test studies with activated sludge taken from the membrane bioreactor and with application of granular activated carbon (GAC) filtration resulted in giving an overall assessment of removal efficiency. Metoprolol and carbamazepine tend to be resistant to the biodegradation process and in the dosed high concentration lead to bacterial cell decomposition in the activated sludge. Apparently, removal efficiency for naproxen exceeded the value of 46% with the spiked initial amount of 3.3 mg NAP g^-1MLSS. Application of the GAC filtration proved to be an efficient technique for removal of pharmaceutical compounds from treated wastewater.</p><p>Application of the statistical programme Modde7 was a time saving tool in studies of fouling occurrence. The effect of fouling phenomenon, which is a highly limiting factor for MBR performance, was minimised by adjusting the operational parameters as predicted by the Modde7 programme.</p>