Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work was carried out in the county of Valen?a - RJ, with the objective to evaluate production and quality of the stargrass, in function of: two irrigation levels (with and without); four cut intervals (21, 28, 35 and 42 at the rainy season and 28, 35, 42 and 49 days at the dry season of the year); as well as four levels of nitrogen (0, 150, 300 e 600 kg/ha/year). The dry matter production (DMP) and the efficiency of the nitrogen utilization (ENU) in plots of 6,25 m2, were estimated from October 2004 to October 2005. In the months of January, June/July and September/October samples were collected to determine chemical composition and digestibility such as: crude protein (CP), neutral-detergent fiber (NDF) and in vitro dry matter digestibility (IVDMD). The Irrigation when increased DMP and ENU, reduced the forrage quality and only had significative effect (P<0,05) during the rainy season. The harvest intervals does not affected (P>0,05) on DMP. However, there was tendency to increase. Harvest intervals should be 42/49 days to obtain good forage quality and yield. The chemical composition and digestibility of the dry matter decreased with the spacing of the cuts and the effect of the interval of cuts on ENU was dependent of the irrigation. At that time it dries the irrigated treatments had her ENU increased with the decrease of the frequency of the cut. The nitrogen fertilization was the only factor that increased (P<0,05) DMP and the quality of the stargrass. However, the answer of DMP to the nitrogen fertilization was reduced and ENU was not affected in function of the nitrogen levels. In the conditions of experiment was realized, it is approved as the most appropriate handling of the studied factors: The interval of cuts of 42/49 days, that formed an alliance high yield with a satisfactory quality and the irrigation, only accomplished in favorable climatic conditions. / Este trabalho foi conduzido no munic?pio de Valen?a - RJ, com o objetivo de avaliar a produ??o e a qualidade do capim-estrela, em fun??o de: dois regimes h?dricos (irrigado e n?o-irrigado); quatro intervalos de cortes (21, 28, 35 e 42 na ?poca chuvosa e 28, 35, 42 e 49 dias na ?poca seca do ano); e quatro doses de nitrog?nio (0, 150, 300 e 600 kg/ha/ano). Durante o per?odo de outubro de 2004 a outubro de 2005, foram estimadas a produ??o de mat?ria seca (PMS) e a efici?ncia da aduba??o nitrogenada (EAN) em parcelas de 6,25 m2. Nos meses de janeiro, junho/julho e setembro/outubro coletaram-se amostras para a estimativa do valor nutritivo e digestibilidade, determinando a prote?na bruta (PB), a fibra em detergente neutro (FDN) e a digestibilidade in vitro da mat?ria seca (DIVMS). Os resultados mostraram que a irriga??o aumentou a PMS e a EAN, reduziu o valor nutritivo e DIV da mat?ria seca. Entretanto somente houve resposta (P<0,05) ao regime h?drico apenas quando as condi??es clim?ticas n?o foram limitantes ao crescimento da forrageira. O intervalo de cortes n?o alterou (P>0,05) a PMS, embora tenha sido observada a tend?ncia de incremento da mesma em fun??o da diminui??o da freq??ncia de cortes, sendo a maior produ??o obtida nos tratamentos 42/49 dias. A qualidade da forrageira diminuiu com o espa?amento dos cortes e o efeito do intervalo de cortes sobre a EAN foi dependente da irriga??o. Na ?poca seca do ano os tratamentos irrigados tiveram sua EAN aumentada com a diminui??o da freq??ncia do corte. A aduba??o nitrogenada foi o ?nico fator que aumentou (P<0,05), simultaneamente, a PMS e a qualidade do capim-estrela. No entanto, a resposta da PMS ? aduba??o nitrogenada foi pequena e a EAN n?o foi alterada (P>0,05) em fun??o das doses de nitrog?nio. Nas condi??es experimentais, preconiza-se como o manejo mais adequado: o intervalo de cortes de 42/49 dias, que aliou rendimentos elevados a uma qualidade satisfat?ria; e a irriga??o deve ser usada apenas quando as condi??es clim?ticas s?o favor?veis.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-10-13T20:11:22Z No. of bitstreams: 1 2016 - Leonardo dos Santos Fran?a Shockness.pdf: 1003791 bytes, checksum: efd5f4204bec8c095ea24c37002fd302 (MD5) / Made available in DSpace on 2017-10-13T20:11:22Z (GMT). No. of bitstreams: 1 2016 - Leonardo dos Santos Fran?a Shockness.pdf: 1003791 bytes, checksum: efd5f4204bec8c095ea24c37002fd302 (MD5) Previous issue date: 2016-02-29 / CAPES / One of the main factors that affect growth and persistence of grasses in the tropics, thus increasing the degradation of pastures, is a nitrogen deficiency in the soil. However, nitrogen fertilizers much burden the production costs, and the demand for food increasing year by year, has emphasized the need for sustainable alternatives, such as biological nitrogen fixation. It is necessary to do more research on Biological Nitrogen Fixation (BNF) in forage grasses, especially about diversity among nitrogen-fixing bacteria associated with these plants, so that new bacteria can be discovered, as well as its potential to FBN. This study aimed to isolate diazotrophic bacteria of the genus Azospirillum spp. or Herbaspirillum spp., from two cultivars of B. brizhanta (Marandu and Xara?s) and one of B. decumbens (IPEAN), to test them, and to assess their contribution to the growth of Brachiaria brizhanta cv. Marandu identifying the three most promising. This study was conducted at Embrapa Agrobiology in Serop?dica - RJ, in two stages. The first was to isolate possible diazotrophic bacteria from Brachiaria brizantha and B. decumbens plants, using the cultivars Marandu and Xara?s B. brizantha, and the cultivar IPEAN of B. decumbens. The isolation was performed using three semi-solid media, NFB, LGI and JNFb, where the first two selected bacteria of the genus Azospirillum, and the third one Herbaspirillum bacteria. There were selected 46 isolates and, after purification, it was obtained 15 isolates pure, and made the phenotypic characterization thereof. Further biochemical tests were the phosphate solubilization, acetylene reduction analysis (ARA), and production of acid-3-indole acetic (IAA). All tested isolates produced ARA ethylene, even in small quantities, with prominence for isolates L2, L4, J3, J6, J7 and J8. In the phosphate solubilization the isolates N1, L1, J2, J3, J4, J5, J6, J7, J8, and T14 were able to solubilize phosphate. In the EIA production the isolates N1, J1, J2, J3, J4, J5, J6, J7, J8 and J9 excelled. In the second phase it was conducted an experiment to study plant - bacteria interaction. It consisted of the inoculation of 15 isolates from the first phase plus three isolates known as references (SP245, Z94, CBAMC) in B. brizhanta cultivar Marandu, plus the control without inoculation and without N. In this experiment the isolates L2, L4 and J6 outstand when compared to the other seven parameters evaluated. On the basis of this study we can conclude that there are nitrogen fixing bacteria, phosphate solubilizing, and that produce 3-indoleacetic acid, associated to Brachiaria brizhanta and Brachiaria decumbens. The isolated bacteria of the two B. brizhanta cultivars (Marandu and Xara?s), and the Brachiaria decumbens (IPEAN) cultivar were more efficient in the growth of B. brizhanta cultivar Marandu than the bacteria standards obtained from other plant species. Also, among the 15 isolates from Brachiaria plants, the J6, L2 and L4 were statistically different from the others, and are considered the three most promising. / Um dos principais fatores que afeta o crescimento e a persist?ncia de gram?neas nos tr?picos, aumentando assim a degrada??o das pastagens, ? a defici?ncia de nitrog?nio no solo. Entretanto, fertilizantes nitrogenados oneram muito os custos de produ??o, e com a demanda por alimentos crescendo ano a ano, tem-se enfatizado a necessidade de alternativas sustent?veis, tal como a fixa??o biol?gica de nitrog?nio. Faz-se necess?rio pesquisas com Fixa??o Biol?gica de Nitrog?nio (FBN) em gram?neas forrageiras, principalmente sobre diversidade de bact?rias diazotr?ficas associadas a essas plantas, para que novas bact?rias possam ser descobertas, assim como seu potencial de FBN. Este trabalho teve como objetivo isolar bact?rias diazotr?ficas do g?nero Azospirillum Spp. ou Herbaspirillum Spp., provenientes de duas cultivares de B. brizhanta (Marandu e Xar?es) e de uma cultivar de B. decumbens (Ipean), testar as mesmas, e avaliar sua contribui??o no crescimento de Brachiaria brizhanta cv. Marandu identificando as tr?s mais promissoras. O trabalho foi realizado na Embrapa Agrobiologia em Serop?dica ? RJ, em duas etapas. Na primeira foi feito o isolamento de poss?veis bact?rias dizotr?ficas provenientes de plantas de Brachiaria brizantha e Brachiaria decumbens, sendo utilizadas as cultivares Marandu e Xara?s de B. brizantha e a cultivar IPEAN de B. decumbens. O isolamento foi realizado utilizando tr?s meios semiss?lidos, NFB, LGI e JNFB, onde os dois primeiros selecionaram bact?rias do g?nero Azospirillum, e o terceiro bact?rias do g?nero Herbaspirillum. Foram selecionados 46 isolados, e ap?s a purifica??o obteve-se 15 isolados puros, sendo feita a caracteriza??o fenot?pica dos mesmos, e posteriormente os testes bioqu?micos de solubiliza??o de fosfato, an?lise da redu??o de acetileno (ARA) e produ??o de ?cido-3-indolac?tico (AIA). Na ARA todos isolados avaliados produziram etileno, mesmo em pequenas quantidades, tendo destaque os isolados L2, L4, J3, J6, J7, e J8. Na solubiliza??o de fosfato os isolados N1, L1, J2, J3, J4, J5, J6, J7, J8 e T14 foram capazes de solubilizar fosfato. Na produ??o de AIA se sobressa?ram os isolados N1, J1, J2, J3, J4, J5, J6, J7, J8 e J9. Na segunda etapa foi realizado o experimento de intera??o planta - bact?ria; que consistiu da inocula??o dos 15 isolados da primeira etapa, acrescidos de tr?s isolados conhecidos como padr?es (SP245, Z94, CBAMC) em B. brizhanta cv. Marandu, mais a testemunha n?o inoculada e sem N. Neste experimento os isolados L2, L4 e J6 se destacaram em rela??o aos outros nos sete par?metros avaliados. Com base neste trabalho podemos concluir que existem bact?rias fixadoras de nitrog?nio, solubilizadoras de fosfato e que produzem ?cido-3-indolac?tico associadas a Brachiaria brizhanta e Brachiaria decumbens. As bact?rias isoladas de duas cultivares de B. brizhanta (Marandu e Xar?es) e de uma cultivar de B. decumbens (Ipean) se mostraram mais eficientes no crescimento de B. brizhanta cv. Marandu do que as bact?rias padr?es provenientes de outras esp?cies de plantas. Ainda, dentre os 15 isolados de plantas do g?nero Brachiaria, os isolados J6, L2 e L4 diferiram estatisticamente dos demais, sendo considerados os tr?s mais promissores.

A broca-da-cana Diatraeasaccharalis(Fabricius) é uma das pragas-alvo do milho geneticamente modificado que expressagene(s) que codifica(m) proteína(s) de BacillusthuringiensisBerliner(milho Bt) no Brasil. Para estabelecer estratégias proativas de manejo de resistência, os objetivos do presente trabalho foram (1)estabelecer linhas-básicas de suscetibilidade à proteína Cry1F de B. thuringiensisem populações de D. saccharalis coletadas nas principais regiões produtoras de milho no Brasil na safra de 2010/2011, (2) realizar monitoramentoda suscetibilidade de populações de D. saccharalis na safra 2011/2012 e (3) avaliar a atividade biológica do milho Bt (evento TC1507) em diferentes estádios fenológicos no controle de D. saccharalis em condições laboratoriais. Para a caracterização das linhas-básicas de suscetibilidade foram realizados bioensaios com a proteína purificada Cry1F aplicada superficialmente em dieta artificial.As CL50 de Cry1F estimadas variaram de 0,47 a 7,02 ng de Cry1F/ cm2 dieta artificial para as populações avaliadas (variação de ?15 vezes). Foi definida e validada a concentração diagnóstica de 112 ng de Cry1F/cm²,baseada na estimativa da CL99 das populações testadas para o monitoramento da suscetibilidade. A avaliação da atividade biológica de milho Bt (evento TC1507) foi realizada com dois híbridos (Pioneer 30F35 e Dow 2B688) nos estádios fenológicos V3, V6 e V9 e em duas épocas de plantio. Alta atividade de controle de D. saccharalis foi obtida para os dois híbridos de milho Bt nos diferentes estádios fenológicos e épocas de plantio. Portanto, verificou-se que a espécie D. saccharalis é altamente suscetível à proteína Cry1F. Contudo, a implementação de estratégias de manejo da resistência é de fundamental importância para preservar a vida útil da tecnologia de milho Bt como importante ferramenta em programas de MIP. / The sugarcane borer Diatraeasaccharalis (Fabricius) is one of the target pests of genetically modified maizeexpressinggenes that code for insecticidal proteins from Bacillus thuringiensis Berliner (Bt maize) in Brazil. To implement proactive resistance management strategies, we leaded studies (1) to establish baseline susceptibility to Cry1F protein from B. thuringiensis in populations of D. saccharalis collected from major maize production regions in Brazil during 2010/2011 growing season, (2) to leadsusceptibility monitoring in populations of D. saccharalis collected in 2011/2012 growing season, and (3) to assess the biological activity of Bt maize (event TC1507) at different growth stages forD. saccharaliscontrol under laboratory conditions. The baseline susceptibility wascharacterizedwith purified protein Cry1F applied superficially on artificial diet. The estimatesof LC50 of Cry1F ranged from 0.47 to 7.02 ng Cry1F/cm2of artificial diet for the populations evaluated (? 15-fold variation).A diagnostic concentration of 112 ng Cry1F/cm ² was defined and validated for monitoring the susceptibility based on estimation of CL99 of all tested populations. The biological activity of Bt maize (event TC1507) was assessed by using two hybrids (Pioneer 30F35 and Dow 2B688) at growth stages V3, V6 and V9 and two planting seasons. High level of D. saccharaliscontrol was obtained for the twoBt maize hybrids at different growth stages and planting seasons. Therefore, we conclude that D. saccharalis is highly susceptible to Cry1F protein. However, implementation of insect resistance management strategies is essentialin order to preserve the lifetime of Bttechnology as an important tool in IPM programs.

In modern computer systems, memory accesses and power management are the two major performance limiting factors. Accesses to main memory are very slow when compared to operations within a processor chip. Hardware write buffers, caches, out-of-order execution, and prefetch logic, are commonly used to reduce the time spent waiting for main memory accesses. Compiler loop interchange and data layout transformations also can help. Unfortunately, large data structures often have access patterns for which none of the standard approaches are useful. Using smaller data structures can significantly improve performance by allowing the data to reside in higher levels of the memory hierarchy. This dissertation proposes using lossy data compression technology called ’Compressive Hashing’ to create “surrogates”, that can augment original large data structures to yield faster typical data access. One way to optimize system performance for power consumption is to provide a predictive control of system-level energy use. This dissertation creates a novel instruction-level cost model called the variable-n-gram model, which is closely related to N-Gram analysis commonly used in computational linguistics. This model does not require direct knowledge of complex architectural details, and is capable of determining performance relationships between instructions from an execution trace. Experimental measurements are used to derive a context-sensitive model for performance of each type of instruction in the context of an N-instruction sequence. Dynamic runtime power prediction mechanisms often suffer from high overhead costs. To reduce the overhead, this dissertation encodes the static instruction-level predictions into a data structure and uses compressive hashing to provide on-demand runtime access to those predictions. Genetic programming is used to evolve compressive hash functions and performance analysis of applications shows that, runtime access overhead can be reduced by a factor of ~3x-9x.

Exposure to antibiotics is an important factor influencing the development of bacterial resistance.  In an era where very few new antibiotics are being developed, a strategy for the development of optimal dosing regimen and combination treatment that reduces the rate of resistance development and overcome existing resistance is of utmost importance. In addition, the optimal dosing in subpopulations is often not fully elucidated. The aim of this thesis was to develop pharmacokinetic (PK) and pharmacokinetic-pharmacodynamic (PKPD) models that characterize the interaction of antibiotics with bacterial growth, killing and resistance over time, and can be applied to guide optimization of dosing regimens that enhance the efficacy of mono- and combination antibiotic therapy. A mechanism-based PKPD model that incorporates the growth, killing kinetics and adaptive resistance development in Escherichia coli against gentamicin was developed based on  in vitro time-kill curve data. After some adaptations, the model was successfully applied for similar data on colistin and meropenem alone, and in combination, on one wild type and one meropenem-resistant strain of Pseudomonas aeruginosa. The developed population PK model for colistin and its prodrug colistin methanesulfonate (CMS) in combination with the PKPD model showed the benefits for applying a loading dose for this drug. Simulations predicted the variability in bacteria kill to be larger between dosing occasions than between patients. A flat-fixed loading dose followed by an 8 or 12 hourly maintenance dose with infusion duration of up to 2 hours was shown to result in satisfactory bacterial kill under these conditions. Pharmacometric models that characterize the time-course of drug concentrations, bacterial growth, antibacterial killing and resistance development were successfully developed. Predictions illustrated how PKPD models based on in vitro data can be utilized to guide development of antibiotic dosing, with examples advocating regimens that (i) promote bacterial killing and reduce risk for toxicity in preterm and term newborn infants receiving gentamicin, (ii) achieve a fast initial bacterial killing and reduced resistance development of colistin in critically ill patients by application of a loading dose, and (iii) overcome existing meropenem resistance by combining colistin and meropenem

With the increase in the complexity of computer systems, existing security measures are not enough to prevent attacks. Intrusion detection systems have become an integral part of computer security to detect attempted intrusions. Intrusion detection systems need to be fast in order to detect intrusions in real time. Furthermore, intrusion detection systems need to be robust against the attacks which are disguised to evade them. We improve the runtime complexity and space requirements of a host-based anomaly detection system that uses q-gram matching. q-gram matching is often used for approximate substring matching problems in a wide range of application areas, including intrusion detection. During the text pre-processing phase, we store all the q-grams present in the text in a tree. We use a tree redundancy pruning algorithm to reduce the size of the tree without losing any information. We also use suffix links for fast linear-time q-gram search during query matching. We compare our work with the Rabin-Karp based hash-table technique, commonly used for multiple q-gram matching. To analyze the robustness of network anomaly detection systems, we develop a new class of polymorphic attacks called polymorphic blending attacks, that can effectively evade payload-based network anomaly IDSs by carefully matching the statistics of the mutated attack instances to the normal profile. Using PAYL anomaly detection system for our case study, we show that these attacks are practically feasible. We develop a formal framework which is used to analyze polymorphic blending attacks for several network anomaly detection systems. We show that generating an optimal polymorphic blending attack is NP-hard for these anomaly detection systems. However, we can generate polymorphic blending attacks using the proposed approximation algorithms. The framework can also be used to improve the robustness of an intrusion detector. We suggest some possible countermeasures one can take to improve the robustness of an intrusion detection system against polymorphic blending attacks.

To fortify their cytoplasmic membrane and protect it from osmotic rupture, most bacteria surround themselves with a peptidoglycan (PG) exoskeleton. The PG synthases that build this structure are called penicillin-binding proteins (PBPs). Since they are the targets of penicillin and related antibiotics, the structures and in vitro biochemical functions of the PBPs have been extensively studied. However, the in vivo functions of the PBPs and the factors they work with to build the PG meshwork remain poorly understood. PBPs work in the context of multicomponent complexes organized by cytoskeletal elements. A major outstanding question has been whether or not these complexes contain factors required for PBP function. I addressed this using Escherichia coli as a model system by taking advantage of the synthetic lethal phenotype resulting from simultaneous inactivation of the major PG synthases: PBP1a and PBP1b. Using a screen for mutants synthetically lethal with the inactivation of PBP1b, I identified LpoA as a factor required for PBP1a function. A colleague in the lab performed the analogous screen for mutants synthetically lethal with the inactivation of PBP1a and identified LpoB as a factor required for PBP1b function. We showed that the Lpo factors are outer membrane lipoproteins that form specific trans-envelope complexes with their cognate PBPs in the inner membrane and that LpoB can stimulate the activity of PBP1b in vitro. Our results reveal unexpected complexity in the control of PBP activity and indicate that they likely receive regulatory input from the outer membrane in addition to cytoskeletal elements in the cytoplasm. To investigate the role of LpoB in morphogenesis further, I took a genetic approach that has identified PBP1b* variants capable of functioning in vivo in the absence of LpoB. Preliminary characterization of these variants indicates that LpoB has cellular functions in addition to PBP1b activation and that LpoB may be important for coordinating the two different catalytic activities of PBP1b. Future study of these mutants is likely to uncover important insights into PBP function and their control by the Lpo factors. These insights may open new avenues for the development of novel therapeutics that target the PBPs.

<p>Nitric oxide (NO) is an endogenous gaseous signaling molecule produced by three NO synthase isoforms (NOS1, 2, 3) and important in host defense. The induction of NOS2 during bacterial sepsis is critical for pathogen clearance but its sustained activation has long been associated with increased mortality secondary to multiple organ dysfunction syndrome (MODS). High levels of NO produced by NOS2 incite intrinsic cellular dysfunction, in part by damaging macromolecules through nitration and/or nitrosylation. These include mitochondrial DNA (mtDNA) and enzymes of key mitochondrial pathways required for maintenance of normal O2 utilization and energy homeostasis. However, animal studies and clinical trials inhibiting NOS2 have demonstrated pronounced organ dysfunction and increased mortality in response to live bacterial infections, confirming that NOS2 confers pro-survival benefits. Of particular interest here, the constitutive NOS1 and NOS3 have been linked to the up-regulation of nuclear genes involved in mitochondrial biogenesis but no comparable role has been described for NOS2. <italic> Therefore, I hypothesized that NOS2 is indispensible for host protection but must be tightly regulated to ensure NO levels are high enough to activate mitochondrial and other pro-survival genes, but below the threshold for cellular damage.</italic></p><p>This hypothesis was explored with two major Aims. The <italic>first Aim</italic> was to define the role of NOS2 in the activation of mitochondrial biogenesis in the heart of <italic>E. coli</italic>-treated mice. The <italic>second</italic> was to investigate the ability of NOS2 to be transcriptionally regulated by an enzyme previously shown to induce mitochondrial biogenesis, heme oxygenase-1 (HO-1). This hypothesis was tested using an <italic>in vivo</italic> model of sublethal heat-killed <italic>E. coli</italic> (<italic>HkEC</italic>) peritonitis in C57B/L6 (Wt), NOS2-/-, and TLR4-/- mice. Additionally, <italic>in vitro</italic> systems of mouse AML-12 or Hepa 1-6 cells pretreated with HO-1 activators or <italic>Hmox1</italic> shRNA prior to inflammatory challenge with lipopolysaccharide (LPS) +/- tumor necrosis factor-&alpha; (TNF-&alpha;). For the first Aim, Wt, NOS2-/-, and TLR4-/- mice were treated with (<italic>HkEC</italic> and cardiac tissue analyzed for mitochondrial function, expression of nuclear and mitochondrial proteins needed for mitochondrial biogenesis, and histological expression of NOS2 and TLR4 relative to changes in mitochondrial mass. For the second Aim, Wt mice were pretreated with hemin or carbon monoxide (CO) to activate HO-1 prior to <italic>HkEC</italic>-peritonitis. Liver tissue in these animals was evaluated at four hours for HO-1 induction, <italic>Nos2</italic> mRNA expression, cytokine profiles, and nuclear factor (NF)-&kappa;B activation. Liver cell lines were pretreated with hemin, CO-releasing molecule (CORM), or bilirubin one hour before LPS exposure and the <italic>Nos2</italic> transcriptional response evaluated at two and 24 hours. The MTT assay was used to confirm that <italic>in vitro</italic> treatments were not lethal. </p><p>These studies demonstrated that <italic>HkEC</italic> induced mtDNA damage in the heart that was repaired in Wt mice but not in NOS2-deficient mice. In KO mice, sustained mtDNA damage was associated with the reduced expression of nuclear (NRF-1, PGC-1&alpha;) and mitochondrial (Tfam, Pol-&gamma;) proteins needed for mitochondrial biogenesis. The findings thus supported that NOS2 is required for mitochondrial biogenesis in the heart during Gram-negative challenge. Evaluation of the relationship between HO-1 and NOS2 in murine liver was more complex; HO-1 activation in <italic>HkEC</italic>-treated Wt mice attenuated 4-hour <italic>Nos2</italic> gene transcription. In liver cell lines, hemin, CORM, and bilirubin were unable to suppress <italic>Nos2</italic> expression at the time of maximal induction (2 hours). <italic>Nos2</italic> was, however, suppressed by 24 hours, suggesting that the regulatory impact of HO-1 induction was not engaged early enough to reduce <italic>Nos2</italic> transcription at 2 hours. It is concluded that NOS2 induction in bacterial sepsis optimizes the expression of the mitochondrial biogenesis transcriptional program, which subsequently can also be regulated by HO-1/CO in murine liver. This provides a potential new mechanism by which immune suppression and mitochondrial repair can occur in tandem during the acute inflammatory response.</p> / Dissertation

The enzyme 3-deoxy-D-manno-octulosonate 8-phosphate (KDO8P) synthase catalyses the aldol condensation of the five-carbon sugar phosphate, arabinose 5-phosphate (A5P), and phosphoenol pyruvate (PEP) to give the eight-carbon phosphorylated sugar, KDO8P. It is the second committed step in the synthesis of KDO, a necessary component of the cell wall of Gram-negative bacteria. This thesis describes the design, synthesis and evaluation of a number of inhibitors of KDO8P synthase that utilise the functionality of one or both substrates. The KDO8P synthase family can be divided based on the requirement of a divalent metal ion. Chapter 2 describes the growth, purification and characterisation of an example from both the metal-independent KDO8P synthases (Neisseria meningitidis, Nme) and metal-dependent KDO8P synthases (Acidithiobacillus ferrooxidans, Afe) in order to utilise these enzymes for the inhibition studies described in this thesis. In Chapter 3, a number of small molecule PEP analogues were selected as mimics of KDO8P synthase reaction intermediates and tested as inhibitors of KDO8P synthase from N. meningitidis and A. ferrooxidans. Glyphosate, (E)-vinyl phosphonate and the fluorinated analogue of (E)-vinyl phosphonate were selected as mimics of the high-energy oxocarbenium intermediate through which the KDO8P synthase reaction is thought to occur. The two enantiomers of phospholactate were selected in order to investigate the chirality of the tetrahedral intermediate and determine the importance of this chirality for inhibition of KDO8P synthase. All five inhibitors were found to be moderate to poor inhibitors of both the KDO8P synthase from N. meningitidis and A. ferrooxidans. Chapter 4 describes the design and synthesis of inhibitors that incorporated structural features of the second substrate, A5P, in order to improve inhibition from that observed for the PEP analogues investigated in Chapter 3. A bisphosphate inhibitor was designed that incorporated a terminal phosphate moiety, representative of the phosphate of A5P. A large increase in inhibition was found, compared to the phospholactates from which it was derived. A structure-activity-relationship study was undertaken on this compound by design of compounds that lacked one of the two phosphate moieties of the bisphosphate inhibitor, in order to determine their relative importance. The inhibition results indicate that the primary terminal phosphate, thought to bind in the A5P phosphate binding site, is more important for inhibition of KDO8P synthase than the secondary phosphate. In Chapter 5 these investigations into the inhibition of KDO8P synthase are discussed in detail, and interpreted using the aid of computational studies. In addition several approaches are described for the completion and advancement of the studies presented here in this thesis.

In praktischen Aufgabenstellungen können zur Modellierung zufälliger Einflüsse, welche sich durch schwache Abhängigkeiten auszeichnen, schwach korrelierte zufällige Funktionen genutzt werden. Die nähere Untersuchung von Funktionalen schwach korrelierter zufälliger Funktionen ist durch die Gestalt der Lösungen von praktischen Fragestellungen motiviert. Die stochastischen Charakteristiken dieser Lösungen lassen sich im Allgemeinen nicht exakt bestimmen, so dass auf Approximationsverfahren zurückgegriffen werden muss. Diese stehen im Mittelpunkt der Dissertation. Zu Beginn werden Entwicklungen von Momenten und Kumulanten der betrachteten linearen Integralfunktionale schwach korrelierter Prozesse nach der Korrelationslänge des Prozesses hergeleitet und eine Vermutung über die exakte Darstellung der Kumulanten formuliert. Für Integralfunktionale von schwach korrelierten Simulationsprozessen, welche aus der Interpolation von Moving-Average-Prozessen entstehen, werden die definierten Charakteristiken hergeleitet. Außerdem steht die Approximation der unbekannten Dichtefunktion im Fokus der Arbeit. Es werden verschiedene Zugänge genutzt. Eine alternative Herleitung zur bereits in der Literatur untersuchten Gram-Charlier-Entwicklung wird in Form der Edgeworth-Entwicklung angegeben. Des Weiteren werden die Sattelpunkt-Approximation und die Maximum-Entropie-Methode untersucht und anhand von Simulationsergebnissen für Integralfunktionale von Simulationsprozessen miteinander verglichen. / In engineering applications stochastic influences which are characterized by weak dependencies can be modelled, among others, by weakly correlated random functions. The solutions of such problems shape up as integral functionals of weakly correlated random functions which motivates more detailed investigations. In general the exact calculation of stochastic characteristics of such integral functionals is impossible so that we have to be content with approximation methods this thesis focuses on. At the beginning expansions of moments and cumulants of linear integral functionals of weakly correlated random processes with respect to the correlation length are considered and an explicit formula of cumulants is conjectured. For integral functionals of weakly correlated random simulation processes, defined as interpolations of moving average processes, the required expansion coefficients are derived. Furthermore the approximation of the unknown probability density is requested. In the thesis there are different approaches used. First we state an alternative way to achieve the already known Gram Charlier approximation by means of Edgeworth expansion. Then we study two further methods, namely the saddlepoint approximation and the maximum entropy method and compare them on the basis of simulation results for integral functionals of simulation processes.