Analyse des Influenzastatus von Hausgeflügel in Freilandhaltung unter besonderer Berücksichtigung der Infektionsgefährdung durch Wildvögel

Wilde Wasservögel sind das natürliche Reservoir von Influenzaviren. Auch in Deutschland wurden in den letzten Jahren insbesondere in durchziehenden Wildenten Influenzaviren verschiedener Subtypen nachgewiesen, einschließlich der potentiellen Erreger der Geflügelpest H5 und H7. Bei Geflügelhaltungen mit Freilandauslauf besteht wegen möglicher Wildvogelkontakte ein erhöhtes Infektionsrisiko für das Wirtschaftsgeflügel, das untersucht werden sollte. In einer deutschlandweiten Stichprobe wurden insgesamt 486 Geflügelbetriebe mit Freilandauslauf auf das Vorkommen von aviären Influenzaviren getestet. Bei 2,9 % der 205 untersuchten Gänsebestände und bei 0,7 % der 143 Entenbestände wurde eine Influenzavirusinfektion nachgewiesen. Die 117 untersuchten Hühnerbestände sowie die 7 Putenbestände und 14 Hobbyhaltungen waren nicht infiziert. Die direkt oder über Antikörper nachgewiesenen Influenzaviren gehörten zu den Subtypen H3, H4, H6 und H12. Aus den angegebenen Daten der untersuchten Bestände zu Haltungs- und Hygieneparametern sowie zu möglichen und wirklich beobachteten Kontakten zu Wildvögeln wurde das spezifische Infektionsrisiko mittels eines Punktesystems eingestuft. Alle mit Influenzavirus infizierten Betriebe hatten ein mittleres Infektionsrisiko. Obwohl bei ca 10 % der Haltungen das Infektionsrisiko als sehr hoch eingestuft wurde, scheint die Ansteckung durch Wildvögel ein sehr seltenes Ereignis zu sein. Vermutet wird, dass es sich bei den in Ausläufen beobachteten Wildvögeln einschließlich der Wildenten um einheimische Standvögel handelte. Die saisonal in großer Zahl auftretenden Durchzügler nutzen Rastgebiete außerhalb der Ansiedlungen. Trotz der geringen Häufigkeit des Viruseintrages durch Wildvögel sollte zur Absicherung der gesamten Geflügelwirtschaft vor der Geflügelpest eine gesetzlich verankerte Überwachung der Geflügelhaltungen mit Freilandauslauf etabliert werden. Sie sollte zweimal jährlich nach dem Vogelzug erfolgen und besonders infektionsgefährdete Bestände umfassen

One-Dimensional Turbulence Simulations for Reactive Flows in Open and Closed Systems

The One-Dimensional Turbulence (ODT) model is applied to reactive flows in open and closed systems represented by a lifted jet flame in a vitiated coflow, and a constant volume autoignition configuration, respectively. ODT is a one-dimensional model for turbulent flow simulations, which uses a stochastic formulation to represent the effects of turbulent advection. Diffusion and reaction effects along the ODT domain are considered by deterministic evolution equations. This work is an effort to verify the applicability and efficiency of the model for open and closed systems. In the open system case, ODT results are compared against experimental results of a lifted methane/air jet flame detailed in the work of Cabra et al. (2005). In the closed system case, a periodic, constant volume domain is used to investigate the sensitivity of the ignition evolution to initial temperature and composition inhomogeneities of a lean n-heptane/air mixture. In the latter context, ODT results are compared to DNS results from Luong et al. (2015). The results for the jet and constant volume configuration show a reasonable match with the experimental and DNS data, considering the reduced order of the model and the underlying assumptions for each case. At the jet configuration, a dependence of the flame evolution on the turbulence intensity parameter can be seen. For the closed system, initial temperature and composition inhomogeneities allow a mitigation of the undesirable rapid pressure rise due to locally different ignition delay times

Avaliação dos níveis transcricionais de genes codificantes para bombas de efluxo em isolados de Mycobacterium tuberculosis resistentes ou não à isoniazida

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Farmácia, Florianópolis, 2017.A Tuberculose (TB) é uma doença causada por bactérias pertencentes ao Complexo Mycobacterium tuberculosis. Segundo a Organização Mundial de Saúde, estimou-se que em 2015, 10,4 milhões de pessoas desenvolveram TB mundialmente e 1,4 milhões morreram em decorrência da doença. No Brasil, foram registrados em 2015, 1027 casos de TB resistente aos fármacos. A isoniazida é um dos fármacos mais efetivos no tratamento da TB. Os principais mecanismos de resistência à isoniazida estão relacionados a mutações nos genes que codificam o ativador do fármaco (gene katG) e o alvo deste (gene inhA). Mutações nos genes katG e inhA são responsáveis por aproximadamente 75% dos casos de M. tuberculosis resistentes à isoniazida, no entanto, em 25% dos casos, tais mutações não são encontradas. Acredita-se que a superexpressão de proteínas do tipo bombas de efluxo sejam responsáveis por este percentual. O aumento na atividade de efluxo resulta na redução das concentrações intrabacterianas do fármaco, o que pode propiciar a sobrevivência de uma subpopulação bacteriana exposta ao constante estresse causado pelas concentrações subinibitórias do fármaco. Durante esta exposição, mutantes com alterações gênicas que favoreçam a resistência podem ser selecionados, possibilitando o estabelecimento de uma população resistente que se torna clinicamente significante. Sendo assim, objetivou-se com o presente estudo, avaliar os níveis de expressão dos genes que codificam para bombas de efluxo mmr, jefA, efpA, bacA e drrA em isolados clínicos de M. tuberculosis com diferentes perfis de susceptibilidade à isoniazida. Os isolados foram categorizados em três grupos: 1. isolados susceptíveis à isoniazida; 2. isolados susceptíveis à isoniazida provenientes de pacientes com baciloscopia positiva ao quarto mês de tratamento e 3. isolados com monorresistência primária à isoniazida. Os resultados obtidos por meio da técnica de Reação em Cadeia da Polimerase Quantitativa em Tempo Real foram comparados entre os grupos e em relação à cepa de referência M. tuberculosis H37Rv. Para os genes jefA, efpA e drrA não foi observada diferença significativa nos níveis de expressão entre os grupos. Desta forma, não foi possível estabelecer uma relação entre os níveis de expressão desses genes e o fenótipo de resistência apresentado pelos isolados. Para os genes mmr e bacA foi encontrada relação significativa entre os níveis basais de expressão e o fenótipo de monorresistência à isoniazida. O gene mmr, o qual codifica para proteínas da família Small Multidrug Resistance, apresentou valores de expressão basal aumentados nos isolados com monorresistência primária à isoniazida quando comparados aos isolados susceptíveis, sugerindo que este gene possa estar relacionado com a resistência à isoniazida. Os níveis de expressão basal do gene bacA nos isolados susceptíveis foram superiores aos níveis encontrados nos isolados com monorresistência primária à isoniazida, sugerindo que níveis reduzidos de expressão do gene bacA possam estar relacionados com a resistência à isoniazida. Os níveis de expressão basal de bacA observados em 83,3% dos isolados clínicos, tanto monorresistentes quanto susceptíveis foram menores que os níveis observados na cepa de referência M. tuberculosis H37Rv. O gene bacA codifica para transportadores do tipo ABC e atua na captação de vitamina B12.Abstract : Tuberculosis (TB) is a disease caused by bacteria belonging to the Mycobacterium tuberculosis Complex. According to the World Health Organization, in 2015, an estimated 10.4 million people developed TB worldwide and 1.4 million died from the disease. In Brazil, 1,027 cases of drug-resistant TB were recorded in 2015. Isoniazid is one of the most effective drugs in the treatment of TB. The major mechanisms of resistance to isoniazid are related to mutations in the genes that encode the drug activator (katG gene) and the drug target (inhA gene). Mutations in katG and inhA genes account for approximately 75% of isoniazid-resistant M. tuberculosis cases; however, in 25% of cases, such mutations are not found. It is believed that overexpression of efflux proteins accounts for this percentage. The increase in efflux activity results in the reduction of intrabacterial drug concentrations, which may lead the survival of a bacterial subpopulation exposed to constant stress of subinhibitory drug concentrations. During this exposition, mutants with alterations in genes that favor resistance can be selected, allowing the establishment of a resistant population that becomes clinically significant. Therefore, the aim of this study was to evaluate the expression levels of efflux pumps genes mmr, jefA, efpA, bacA and drrA in clinical isolates of M. tuberculosis with different isoniazid susceptibility profiles. The isolates were divided into three groups: 1. isoniazid-susceptible isolates, 2. isoniazid-susceptible isolates from patients with positive bacilloscopy after four months of treatment, and 3. isoniazid-resistant isolates. The results obtained using the Quantitative Real-Time Polymerase Chain Reaction technique were compared between the groups and in relation to the reference strain M. tuberculosis H37Rv. For the jefA, efpA and drrA genes, no significant difference in expression levels was observed between groups. Therefore, it was not possible to establish a relationship between the expression levels of these genes and the resistance phenotype of the isolates. For the mmr and bacA genes, a significant relationship was found between the expression levels and the isoniazid-monoresistant phenotype. The mmr gene, which encodes proteins from the Small Multidrug Resistance family, presented increased baseline expression values in isolates with primary isoniazid monoresistance, when compared to susceptible isolates, suggesting that this gene may be related to isoniazid resistance. Basal expression levels of the bacA gene in susceptible isolates were higher than levels found in isolates with primary isoniazid monoresistance, suggesting that reduced levels of the bacA gene may be related to isoniazid resistance. The basal expression levels of bacA observed in 83.3% of clinical isolates, both isoniazid-monoresistant and susceptible, were lower than the levels observed in the reference strain M. tuberculosis H37Rv. The bacA gene codes for ABC type transporters and acts on the uptake of vitamin B12

Ce3+, Eu2+ and Mn2+-activated alkaline earth silicon nitride phosphors and white-light emitting LED

The invention refers to an alkaline earth silicon nitride phosphor of the MSiN2 type that is activated by Ce3+ and/or Eu2+ and/or Mn2+ ions. A preferred embodiment of the phosphor is defined by the general formula MSiN2:A, wherein M is a divalent metal ion, especially Mg, Ca, Sr, Ba, Be and/or Zn, and A is an activator chosen from the group Ce3+, Eu2+ and/or Mn2+. A preferred application for this phosphors is a white-light emitting LED using the phosphor for conversion of radiation

Ce3+, Eu2+ and Mn2+-activated alkaline earth silicon nitride phosphors and white-light emitting LED

The invention refers to an alkaline earth silicon nitride phosphor of the MSiN2 type that is activated by Ce3+ and/or Eu2+ and/or Mn2+ ions. A preferred embodiment of the phosphor is defined by the general formula MSiN2:A, wherein M is a divalent metal ion, especially Mg, Ca, Sr, Ba, Be and/or Zn, and A is an activator chosen from the group Ce3+, Eu2+ and/or Mn2+. A preferred application for this phosphors is a white-light emitting LED using the phosphor for conversion of radiation

Turbulent mixing simulation using the Hierarchical Parcel-Swapping (HiPS) model

Turbulent mixing is an omnipresent phenomenon that permanently affects our everyday life. Mixing processes alsoplays an important role in many industrial applications. The full resolution of all relevant flow scales often poses a major challenge to the numerical simulation and requires a modeling of the small-scale effects. In transported Probability Density Function (PDF) methods, the simplified modeling of the molecular mixing is a known weak point. At this place, the Hierarchical Parcel-Swapping (HiPS) model developed by A.R. Kerstein [J. Stat. Phys. 153, 142-161 (2013)] represents a computationally efficient and novel turbulent mixing model. HiPS simulates the effects of turbulence on time-evolving, diffusive scalar fields. The interpretation of the diffusive scalar fields or a state space as a binary tree structure is an alternative approach compared to existing mixing models. The characteristic feature of HiPS is that every level of the tree corresponds to a specific length and time scale, which is based on turbulence inertial range scaling. The state variables only reside at the base of the tree and are understood as fluid parcels. The effects of turbulent advection are represented by stochastic swaps of sub-trees at rates determined by turbulent time scales associated with the sub-trees. The mixing of adjacent fluid parcels is done at rates consistent with the prevailing diffusion time scales. In this work, a standalone HiPS model formulation for the simulation of passive scalar mixing is detailed first. The generated scalar power spectra with forced turbulence shows the known scaling law of Kolmogorov turbulence. Furthermore, results for the PDF of the passive scalar, mean square displacement and scalar dissipation rate are shown and reveal a reasonable agreement with experimental findings. The described possibility to account for variable Schmidt number effects is an important next development step for the HiPS formulation. This enables the incorporation of differential diffusion, which represents an immense advantage compared to the established mixing models. Using a binary structure allows HiPS to satisfy a large number of criteria for a good mixing model. Considering the reduced order and associated computational efficiency, HiPS is an attractive mixing model, which can contribute to an improved representation of the molecular mixing in transported PDF methods

Formalin-fixed and paraffin-embedded tissues of chickens are useful for retrospective studies on pathology of H5N1 Highly Pathogenic Avian Influenza Virus (HPAI) outbreaks in Nigeria

In a retrospective study, histopathology and immunohistochemistry (IHC) were performed on formalin-fixed paraffin embedded (FFPE) archival tissues from chickens obtained during outbreaks of highly pathogenic avian influenza (HPAI) H5N1 that occurred in Nigeria in 2006 and 2007. Ten samples as representative of 10 outbreaks were selected, and following the detection of HPAI viral antigen in different chicken tissues using IHC, RNA was extracted from each sample and molecular analysis was performed using real-time reverse transcription-polymerase chain reaction (rRT-PCR) targeting matrix protein. Seven rRT-PCR positive samples were then subjected to conventional and rRT-PCR assays for the amplification of hemagglutinin (HA) gene. Four of them were further characterized by sequence analysis of a short HA2-part of the H5 gene. Along the 154 nucleotides sequenced, differences at 4 positions were detected in one sample. One of these mutations led to an amino acid exchange at position 544 (Ala>Thr) whereas the others were silent. The study suggests the potential application for retrospective IHC and PCR analysis of FFPE tissues from chickens involved in the AI outbreaks for pathologic studies and providing short fragment sequences which may help in the characterization of viral strains and tracing the outbreaks. This is important as archived poultry tissues can be re-examined for possibility of earlier introduction of the virus.Keywords: Avian influenza; FFPE; H5N1; Nigeria; Immunohistochemistry; real-time RT-PC

DETERMINAÇÃO DO POTENCIAL DE GERAÇÃO DE BIOGÁS A PARTIR DA BIODIGESTÃO ANAERÓBIA DE RESÍDUOS DA CULTURA DA BANANA INOCULADO COM DEJETO ANIMAL EM ENSAIO BMP

Rafaela Franqueto[1]Ester Kelly Starick[2]Joel Dias da Silva[3]  RESUMOOs resíduos do agronegócio apresentam potencial de reaproveitamento, em especial, por seu valor energético, na utilização como matéria-prima (biomassa) para produção de biogás. Neste processo de reaproveitamento, o ensaio do Potencial Bioquímico de Metano (BMP) pode ser utilizado na determinação de quão representativo é este potencial, ajudando na tomada de decisão na escolha de processos de valorização. O BMP é um ensaio efetuado em laboratório, em condições controladas, segundo recomendações de normas técnicas. Neste contexto, o presente estudo buscou determinar o potencial de geração de biogás a partir de resíduos de cultura de banana inoculado com dejetos animais em diferentes proporções utilizando BMP. O trabalho constituiu-se, inicialmente, de uma revisão bibliográfica, e posteriormente de ensaio experimental. Na etapa experimental, realizou-se: coleta e secagem dos resíduos (folha de bananeira e dejeto bovino), a realização de análises (série de sólidos, umidade, pH), que permitiram determinar as proporções a serem trabalhadas no ensaio experimental, montagem e o monitoramento dos reatores BMP por 60 dias por meio da verificação da variação de temperatura e pressão. Após os 60 dias, os resultados foram analisados levando em consideração a configuração (dejeto bovino:folha de bananeira), quando por fim foi possível determinar que o reator C  (10:1) foi aquele que apresentou os melhores resultados para a geração de biogás quando comparado com os demais reatores, com uma produção máxima de 0,83 NmL de biogás no 36º. dia. O reator A (proporção 1:1) e reator B (proporção 4:1) alcançaram a produção máxima no 7º. dia e 8º. dia; respectivamente, ambos com 0,35 NmL.  

Evaluation of a competitive ELISA for antibody detection against avian influenza virus

Active serologic surveillance is necessary to control the spread of the avian influenza virus (AIV). In this study, we evaluated a commercially-available cELISA in terms of its ability to detect AIV antibodies in the sera of 3,358 animals from twelve species. cELISA detected antibodies against reference H1- through H15-subtype AIV strains without cross reactivity. Furthermore, the cELISA was able to detect antibodies produced following a challenge of the AIV H9N2 subtype in chickens, or following vaccination of the AIV H9 or H5 subtypes in chickens, ducks and geese. Next, we tested the sensitivity and specificity of the cELISA with sera from twelve different animal species, and compared these results with those obtained by the hemagglutination-inhibition (HI) test, the "gold standard" in AIV sera surveillance, a second commercially-available cELISA (IZS ELISA), or the agar gel precipitation (AGP) test. Compared with the HI test, the sensitivities and specificities of cELISA were 95% and 96% in chicken, 86% and 88% in duck, 97% and 100% in turkey, 100% and 87% in goose, and 91% and 97% in swine, respectively. The sensitivities and specificities of the cELISA in this study were higher than those of IZS ELISA for the duck, turkey, goose, and grey partridge sera samples. The results of AGP test against duck and turkey sera also showed significant correlation with the results of cELISA (R-value >0.9). In terms of flock sensitivity, the cELISA correlated better with the HI test than with commercially-available indirect ELISAs, with 100% flock sensitivity