This thesis deals with the problems associated with the lightning. It deals with the stablishment, descriptions and analyzes of risk the living organisms and objects are facing. The work focuses on the description and implementation of protection against these adverse effects. Its objective is to devise a system for lightning protection for chosen PV power plant to meet the requirements of standard of EN 62305. The work is also the analysis of shadow effects in the collecting system for PV power systems.

Die Sepsis ist ein gefürchtetes Krankheitsbild, das in hochentwickelten Industrienationen mit einer hohen Mortalität verknüpft ist und damit zu den häufigsten Todesursachen gehört. Die Pathomechanismen dieses komplexen und heterogenen Krankheitsbildes zu entdecken, gehört momentan zu den Hauptinteressengebieten der Sepsisforschung. Da die Interpretation klinischer Studien aufgrund der Heterogenität des Patientenguts schwierig ist, kommt der Entwicklung adäquater Tiermodelle eine entscheidende Bedeutung zu. Die hierbei gängigen Tiermodelle in Mäusen weisen jedoch Unzulänglichkeiten auf, die die Übertragung der in Tierexperimenten gewonnen Daten auf den klinischen Kontext nur teilweise ermöglichen. Eine Brücke kann hierbei das Tiermodell der humanisierten Maus schlagen, in der, durch Transplantation mit humanen hämatopoetischen Stammzellen, ein humanes Immunsystem reift. Die vorliegende Arbeit beschäftigt sich mit der Fragestellung, inwieweit die humanen Immunzellen in der humanisierten Maus in der Lage sind, auf LPS als Stimmulus zu reagieren. Darüberhinaus wird die Nutzung der Endotoxämie in der humanisierten Maus als alternatives Sepsismodell im Bezug zum klinischen Kontext untersucht. Hierbei ergab sich eine mögliche Nutzung des Endotoxämiemodells in der humanisierten Maus zur genaueren Erforschung des Zytokinmilieus, sowie neuer Surrogatmarker wie Pentraxin 3. Bezüglich der Reaktion einzelner immunologischer Subpopulationen und deren Bedeutung für die Klinik scheint eine Untersuchung an Modellen, die eine B- und T-Zell-Reifung nachvollziehen können und in der murine Residualzellen möglichst gering vorhanden sind, als sinnvoll.

Die meisten Lebewesen nutzen zur Abwehr von pathogenen Mikroorganismen u.a. ein weites Spektrum von antimikrobiellen, oft kationischen Peptiden. Etliche dieser natürlichen und künstlichen Peptide sind in der Lage, Bakterienprodukte wie das Lipopolysaccharid (LPS) Gram-negativer Bakterien zu binden. LPS ist als potenter Stimulator des Immunsystems ein bedeutender Faktor bei der Entstehung von Infektion und Entzündung. LPS-bindende kationische Peptide, zu denen auch von der LPS-Bindungssequenz des Limulus-anti-LPS-Faktors (LALF) abgeleiteten Ringpeptide gehören, wirken synergistisch zu den klassischen Antibiotika, ohne jedoch wie diese zu einer vermehrten LPS-Freisetzung zu führen. LALF-Peptide zeigten in bisher veröffentlichten Versuchen vielversprechende Ergebnisse bei der Bindung von LPS und in murinen Sepsismodellen. In der vorliegenden Arbeit wird in Versuchen mit humanen Monozyten und murinen Makrophagen gezeigt, dass neuartige LALF-Peptide eine durch LPS induzierte Ausschüttung des Zytokins TNF-alpha und des vasoaktiv wirksamen Stickstoffoxids wirkungsvoll unterdrücken können. Ferner wird in LPS-Bindungsassays nachgewiesen, dass dies durch eine Blockierung der LPS-Erkennung durch das LPS bindende Protein (LPB) verursacht wird. Die Verwendung von D-Aminosäuren verspricht dabei in ersten in vitro Experimenten eine Optimierung der Peptid-Eigenschaften. Die Entschlüsselung der Wirkmechanismen dieser neuartigen Peptide könnte Auswirkungen auf die Entwicklung neuer therapeutischer Interventionsstrategien bei Infektion und Sepsis haben. / In host defense against pathogenic microorganisms most organisms employ a broad spectrum of antimicrobial, often cationic peptides. Several of these natural or synthetic peptides are able to bind bacterial products like Lipopolysaccharide (LPS) of Gram-negative bacteria. As a potential stimulator of the immune system LPS is an important pathogenetic factor for infection and inflammation. Cationic LPS-binding peptides like cyclic peptides corresponding to the LPS-binding domain of the Limulus-anti-LPS-factor (LALF) have been shown to act synergistic to classic antibiotics. An advantage of these compounds, however, may be their lack of induction of LPS release. In previous studies LALF-peptides have shown promising results for binding LPS, and in murine sepsis models. Here we show in experiments with human monocytes and murine macrophages that novel LALF-derived peptides are able to effectively block the LPS-induces release of the cytokine TNF-alpha and of the vasoactive nitric oxide. In addition it is shown here by employing an LPS-binding assay that this activity is caused by inhibition of LPS-recognition brought about by the LPS binding protein (LBP). In first in vitro experiments the use of D-amino acids looks promising as they improve peptide quality. To further elucidate the mode of action of these novel peptides could lead to the development of new therapeutic strategies against infection and sepsis.

The proprotein convertases (PC) are endoproteolytic enzymes essential for the generation of bioactive peptides.The production of KO mice for some of these PCs has allowed us to identify many different physiological phenotypes for these enzymes. PC1/3 is traditionally classified as a neuroendocrine enzyme. This has been supported by many studies performed in PC1/3 KO mice, as well as human subjects deficient in PC1/3, where this enzyme is responsible for the cleavage of neuroendocrine substrates, namely POMC and pro-insulin. However, very little research has been done on the potential role of PC1/3 in the immune system, despite evidence of its expression in immune cells, including macrophages. In the present study, we investigate the PC1/3 KO mouse through an immunological aspect. Our laboratory has previously reported an increase in the expression of PC1/3 in the spleen following LPS stimulation. By examining closely the spleen, we observed a splenomegaly of the organ as well as a marked disorganization of the regions of the spleen, such as an invasion of the red pulp with the marginal zone, which may affect the proper immunological response. Labeling of different immune cells demonstrated a decrease in the dendritic cells present in the PC1/3 KO mouse spleen. An interesting phenotype that was observed in the PC1/3 KO mice is their sensitivity to an LPS-induced septic shock, which was evident by an exaggerated secretion of pro-inflammatory cytokines (IL-6, IL-1[bêta] et TNF-[alpha]). Furthermore, the present study identifies the macrophages as major contributors to the unbalanced secretion observed in the PC1/3 KO mice since we report an increase in cytokine secretion in isolated peritoneal macrophages. We also demonstrate a link with the adaptive immune system. A massive secretion of IFN-[gamma] was measured in the PC1/3 KO mouse plasma, supporting the notion that the Th1 pro-inflammatory pathway is predominant in these mice following an LPS challenge. Taking into account these results, the study presented identifies a novel and unconventional role of PC1/3 in the regulation of the innate immune system.

Azijos žemyne formuojasi pasaulio geopolitinis-ekonominis centras. Vienos svarbiausių valstybių šiame procese yra Kinijos Liaudies Respublika (toliau Kinija), Indija ir Pietų Korėja. Geopolitinio-ekonominio centro formavimosi laikotarpiu komplikuotas ir probleminis tampa valstybių ekonominio saugumo užtikrinimas. Iškyla klausimas kokias priemones ir kuo remiantis pasitelkia šios valstybės savo ekonominio saugumo stiprinimui. Šio tyrimo objektas yra Kinijos, Indijos ir Pietų Korėjos ekonominė diplomatija. Darbo tikslas: pritaikyti ir kritiškai įvertinti Herscher-Ohlin-Vanek (HOV) modelį įvykdant Kinijos, Indijos ir Pietų Korėjos ekonominės diplomatijos lyginamąją analizę po įstojimo į Pasaulio Prekybos Organizaciją. Tikslui pasiekti iškeliami šie uždaviniai: 1) ištirti saugumo kaitą ir ekonominės diplomatijos sampratą; 2) įvertinti HOV modelį bei jo metodologinį pritaikymą Kinijos, Indijos ir Pietų Korėjos ekonominės diplomatijos analizei; 3) išanalizuoti esminius Kinijos, Indijos ir Pietų Korėjos ekonominės diplomatijos bruožus; 4) ištirti Kinijos, Indijos ir Pietų Korėjos ekonominės diplomatijos įrankių panaudojimą ekonominiam saugumui užtikrinti; 5) empiriškai palyginus Kinijos, Indijos ir Pietų Korėjos ekonominės diplomatijos įrankius kritiškai įvertinti HOV modelį. Tyrimui naudojami metodai: aprašomasis metodas, kokybinių ir kiekybinių metodų sintezė, ekonominės diplomatijos HOV modelis bei lyginamasis metodas. Atlikus tyrimą gauti rezultatai, jog HOV modelis daugeliu... [toliau žr. visą tekstą] / In Asia develops new world geopolitical-ecanomic centre. Of most important countries in this process are China, India and South Korea. Complicated period of geopolitical-economic centre formation rises vulnerabilies and challenges for the assurance of these countries economic security. Rises questions that means and why use these countries for their economic security strengthening. The object of this research is the economic diplomacy of China, India and South Korea. The goal is: to use and critically evaluate Herscher-Ohlin-Vanek model after accomplished comparative analysis of China, India and South Korea economic diplomacy after their join to the World Trade Organization. The tasks are: 1) to survey the fluctuation of security and conception of economic diplomacy; 2) to evaluate HOV model and its methodological application to the analysis of China, India and South Korea economic diplomacy; 3) to analyse essential features of China, India and South Korea economic diplomacy; 4) to examine China, India and South Korea economic diplomacy tools appliance for the assurance of economic security; 5) after empirical comparision of China, India and South Korea economic diplomacy tools to critically evaluate HOV model. For the research are used: descriptive method, the synthesis of qualitive and quantitive methods, economic diplomacy HOV model and comparative analysis. After research obtained results show that HOV model in most of cases can be used to explain countries‘ economic... [to full text]

Mastitis is often bacterial in origin. Lipoteichoic acid (LTA) and lipopolysaccharide (LPS), endotoxins from gram-positive and gram-negative bacteria, respectively, are potent inducers of mammary gland inflammation. Inflammation can alter expression of transporters responsible for transport of substrates important in synthesis of milk constituents and cellular metabolic energy. Since, gram-positive and gram-negative bacterial infections cause a different clinical course of mastitis, I investigated whether LTA and LPS differentially alter proton-coupled (MCT1) and sodium-coupled monocarboxylate transporter (SMCT1, SMCT2) expression and functional outcomes of altered expression. Human mammary epithelial cells (MCF-12A) were incubated with 1 microgram/mL LPS or LTA for 6, 12 and 24 hours and mRNA expression of TNF-alpha, IL-1β, IL-6, MCT1, SMCT1, and SMCT2 were measured using Quantitative RT-PCR. LPS decreased SMCT1, but increased SMCT2 expression after 6 h, while LTA increased MCT1 expression at 6 h, followed by gradual decrease in expression until 24 h. To know whether such differential changes in transporter expression by LPS and LTA could cause changes in cellular energy production, I quantified creatine (Cr) and high-energy phosphate substrates (CrP, ATP, ADP, AMP) and oxygen consumption rates using HPLC and Hansatech oxygen electrode, respectively. At 12 h, LPS increased concentrations of Cr, CrP, ATP and ADP, whereas LTA caused changes in CrP and ADP concentrations relative to control. Both LPS and LTA decreased oxygen consumption rates after 12 h. Furthermore, to know whether changes in transporter expression lead to differences in substrate availability, I performed uptake studies for carnitine using radiolabelled tritium L-carnitine. LPS and LTA challenge did not affect the affinity, but caused a 2-3-fold increase in maximal activity (Vmax) of carnitine transport. Although increases in Vmax were not significant, the increase in Vmax after 12 h exposure by LPS and LTA corresponds to changes in mRNA expression of the OCTN2 transporter (previously reported in the laboratory). In conclusion, LPS and LTA differentially alter mRNA expression of transporters, which leads to changes in cellular energy levels and oxygen consumption rates and possibly to changes in the functional activity of transporters. Whether such differences contribute to the different clinical course of mastitis warrants further investigation.

This thesis concerns work on structure and membrane interactions of enzymes involved in lipid synthesis, biomembrane and cell wall regulation and cell defense processes. These proteins, known as glycosyltransferases (GTs), are involved in the transfer of sugar moieties from nucleotide sugars to lipids or chitin polymers. Glycosyltransferases from three types of organisms have been investigated; one is responsible for vital lipid synthesis in Arabidopsis thaliana (atDGD2) and adjusts the lipid content in biomembranes if the plant experiences stressful growth conditions. This enzyme shares many structural features with another GT found in gram-negative bacteria (WaaG). WaaG is however continuously active and involved in synthesis of the protective lipopolysaccharide layer in the cell walls of Escherichia coli. The third type of enzymes investigated here are chitin synthases (ChS) coupled to filamentous growth in the oomycete Saprolegnia monoica. I have investigated two ChS-derived MIT domains that may be involved in membrane interactions within the endosomal pathway. From analysis of the three-dimensional structure and the amino-acid sequence, some important regions of these very large proteins were selected for in vitro studies. By the use of an array of biophysical methods (e.g. Nuclear Magnetic Resonance, Fluorescence and Circular Dichroism spectroscopy) and directed sequence analyses it was possible to shed light on some important details regarding the structure and membrane-interacting properties of the GTs. The importance of basic amino-acid residues and hydrophobic anchoring segments, both generally and for the abovementioned proteins specifically, is discussed. Also, the topology and amino-acid sequence of GT-B enzymes of the GT4 family are analyzed with emphasis on their biomembrane association modes. The results presented herein regarding the structural and lipid-interacting properties of GTs aid in the general understanding of glycosyltransferase activity. Since GTs are involved in a high number of biochemical processes in vivo it is of outmost importance to understand the underlying processes responsible for their activity, structure and interaction events. The results are likely to be useful for many applications and future experimental design within life sciences and biomedicine. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Manuscript.</p>

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Cysteine cathepsins B, L and S are endosomal/lysosomal proteases that participate in numerous physiological systems. Cathepsin expression and activity are altered during various inflammatory diseases, including rheumatoid arthritis, atherosclerosis, neurodegenerative diseases and cancers. Early immune responses to microbial pathogens are mediated by pattern-recognition receptors, including Toll-like receptors (TLR). Signaling through TLR causes cell activation and release of inflammatory mediators, which can contribute to the severity of chronic inflammatory diseases. The impact of TLR cell activation on cathepsins B, L and S activities was investigated using live-cell enzymatic assays. Individual ligands of TLR4, TLR2 and TLR3 increased intracellular activities of the three cathepsins indicating the involvement of both MyD88-dependent and -independent pathways. To investigate the role of inflammatory cytokines in regulating these proteases, a lipopolysaccharide (LPS) non-responsive cell line was utilized. LPS non-responsive cells co-cultured with LPS responsive macrophages upregulated cathepsin activities. Furthermore, culture supernatants from LPS-stimulated macrophages increased cathepsin activities in LPS non-responsive cells, which could be reduced by neutralizing antibodies to TNF-α or IL-1β. These findings indicate cytokines regulate cathepsin activities during macrophage responses to TLR stimulation. Using LPS as a model for inflammation, the ability of the cannabinoids, delta9-tetrahydrocannabinol (THC), and CP55940 to suppress cysteine cathepsins during an inflammatory response was investigated. Cannabinoids, including the major psychoactive component of marijuana THC, modulate a variety of immune responses and have been proposed as possible therapeutics to control chronic inflammation. Cannabinoids may mediate their effects through receptor-dependent or independent mechanisms. Cannabinoid receptor subtype 1 (CB1) and receptor subtype 2 (CB2) have differential expression in leukocytes. Dose response studies showed that 1 nM THC was sufficient to inhibit cathepsin enhancement in LPS-stimulated cells. P388D1 macrophages expressed CB2 mRNA, but had no detectable CB1 mRNA indicating a role for the CB2 receptor. Utilizing a CB2-/- macrophage cell line, the role of CB2 receptor participation in THC inhibition of cysteine cathepsin upregulation was explored. THC did not affect cathepsin activity in LPS-stimulated cells lacking CB2 expression. These findings support the possibility of receptor selective agonists as therapeutic treatment during inflammatory diseases to prevent cathepsin involvement in pathological tissue destruction.