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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Broilerkyckling : Fiberrikt foder effektiviserar kycklingproduktionen

Samuelsson, Amanda, Slade, Lovisa, Thörnlund Persson, Sara January 2013 (has links)
Människan har tämjt och fött upp fåglar i 4000 år för att kunna äta deras kött. Idag förtärs broilerkyckling i hela världen och den har blivit ett lättillgängligt livsmedel. Konsumtionen av kyckling ökar och broilerkycklingens kött blir ett allt mer populärare matval. Forskare och producenter försöker upprätthålla den uppåtgående trenden och har därigenom utvecklat fodret, till exempel fiberrikt foder, för att kunna öka produktionen. Syftet med denna uppsats är att undersöka om fiberrikt foder för broilerkyckling kan effektivisera dess tillväxt och därmed öka produktionen så att efterfrågan kan tillgodoses. För att undersöka hur fiberrikt foder påverkar broilerkycklingens tillväxt har en litteraturstudie gjorts. Denna studie visar att det har pågått forskning inom detta ämne sedan 1950-talet. Denna forskning har resulterat i att broilerkycklingens tillväxt ökat markant och därmed har tillgången till kött blivit större. Denna utveckling har skett bland annat på grund av att fodret utvecklats. Fibrer visar sig kunna öka en broilerkycklings tillväxt olika mycket, beroende på om det är lösliga eller olösliga fibrer som tillsätts i fodret. Med olösligt fiber tillsatt i kosten kan broilerkycklingen öka i kroppsvikt och i slutändan tillgodose den stigande konsumtionen med mer kött utvunnet från mindre mängd foder. / B-uppsatser
2

Exogenous enzymes and irradiation of barley reduce the anti-nutritional activity of non-starch polysaccharides in broilers

Drew, Paul John 30 January 2009 (has links)
Interactions between non-starch polysaccharide (NSP) level, dietary lipid type, exogenous carbohydrase enzymes and irradiation were investigated. Ten treatment diets were fed to broilers in a performance and digestibility trial. Eight of the diets contained high levels of NSP, achieved by a high barley inclusion of 55% of the diet. Four of the treatments made use of non-irradiated barley, whereas the barley included in the other four diets was irradiated. By adding either 10% soya oil or yellow grease (fat) as the lipid source, sub groups were created which differed in fatty acid profile. Lastly, these treatments were further subdivided by supplementing one of the two diets from each subgroup with a commercially available combination of exogenous carbohydrase enzymes consisting of cellulases, xylanases and â - glucanases (Roxazyme G at 150 g/ton). The two control diets were based on maize (low NSP diets) with either soy oil or yellow grease. The high NSP diets had significantly lower (P<0.05) apparent metabolisable energy (AME) and lipid digestibility values than the low NSP diets. Lipid digestibility and AME values were also significantly lower (P<0.05) for diets containing yellow grease compared to soya oil. The birds that received yellow grease performed worse in terms of growth, feed intake and feed conversion ratio (FCR) than the oil-containing diets. These trends were evident throughout all treatments, although not always significant. The addition of carbohydrase to diets based on barley improved the dietary lipid digestibility and AME values. Significant improvements (P<0.05) in bird performance were noted for the barley diets with the yellow grease. Pre-irradiation of barley significantly increased (P<0.05) the AME value of diets, and improved lipid digestibility of the fat-containing treatment. The simultaneous combination of carbohydrase supplementation and barley irradiation proved to have an additive positive effect on feed quality and bird performance. For all treatments this combination improved the barley based diets to such an extent that it performed equally or significantly better (P<0.05) than its maize based counterpart. The irradiated barley-yellow grease based diets showed a more pronounced benefit with the addition of carbohydrase enzymes to the feed (P<0.05). / Dissertation (MSc(Agric))--University of Pretoria, 2008. / Animal and Wildlife Sciences / unrestricted
3

An analysis of web shops with New Psychoactive Substances and their marketing strategies

Pažitný, Martin January 2016 (has links)
The emergance of modern technologies has essential impact on the way people communicate, spend lisure and shop. The influence of internet has not avoid the market with psychoactive substances. Aproximately since 2008 has happend significant rise among the sops with new psychadelic substances(NPS). The rise of the shops has risen also an afford to monitor this new phenomenon. This thesis follows project Itrend that haas monitored the NPS shop in 2014 and 2015. The aim of the work is to provide more detailed estimate of this size of the market with NPS and the dynamics of its developement between years 2014 and 2106. The analysis of data overstep frame of project I­Trend. keywords: NSP,web shops, internet,marketing strategies
4

Caracterização funcional de uma PERK quinase de Arabidopsis thaliana que interage com a proteína NSP de Geminivírus / Functional characterization of an Arabidopsis thaliana PERK- like kinase that interacts with the Geminivírus NSP protein

Florentino, Lílian Hasegawa 23 February 2006 (has links)
Made available in DSpace on 2015-03-26T13:36:33Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1875030 bytes, checksum: 2c2c1497d43bb10ad7e10f009f941c57 (MD5) Previous issue date: 2006-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Geminiviruses constitute a large group of plant virus whose genome is packed as single-stranded DNA circles in a small, twinned isometric particle and is converted to double- stranded forms in nuclei of differentiated plant cells. Members of the genus Begomovirus, such as Cabbage leaf curl virus (CaLCuV), possess two genomic components, DNA-A and DNA-B. The DNA-A has the potential to code for five gene products (AV1, AC1, AC2, AC3, AC4) and is involved in replication, transcriptional activation of viral genes and encapsidation of the viral genome. The DNA-B encodes two movement proteins, the movement protein MP (BC1) and the nuclear shuttle protein NSP (BV1), both required for systemic infection. NSP shuttles the viral DNA between the nucleus and the cytoplasm and then acts cooperatively with MP to move the viral DNA cell-to-cell across the wall. The localization of NSP and its proposed role in cell-to-cell movement of the viral DNA predict that interactions with host factors may occur in both the cytoplasm and the nucleus. In fact, NSP has been demonstrated to interact with a plasma membrane receptor protein, designated NIK, and a nuclear acetyltransferase. A proline-rich extensin-like receptor protein kinase (PERK) was found to interact specifically with NSP of CaLCuV and of tomato-infecting geminiviruses, through yeast two-hybrid screening. The PERK-like protein, which we designated NsAK (NSP-associated kinase), is structurally organized into a proline-rich N-terminal domain followed by a transmembrane segment and a C-terminal serine/threonine kinase domain. The viral protein interacted stably with defective versions of the NsAK kinase domain but not with the potentially active enzyme in an in vitro binding assay. In vitro translated NsAK enhanced the phosphorylation level of NSP, indicating that NSP functions as substrate for NsAK. These results demonstrated that NsAK is an authentic serine/threonine kinase and suggested a functional link for the NSP-NsAK complex formation. This interpretation was corroborated by in vivo infectivity assays showing that loss of NsAK function delays the onset of CaLCuV infection and attenuates symptom development. Our data implicate NsAK as a positive contributor to geminivirus infection and suggest it may regulate NSP function. / Geminivírus constitui um grande grupo de vírus de planta, cujo genoma é empacotado na forma de DNA circular fita simples em partículas icosaédricas geminadas e é convertido em uma forma fita dupla no núcleo de células diferenciadas de plantas. A maioria dos membros do gênero Begomovirus, como o Cabbage leaf curl vírus (CaLCuV), possuem dois componentes genômicos, DNA-A e DNA-B. O DNA-A apresenta o potencial para codificar cinco produtos gênicos (AV1, AC1, AC2, AC3, AC4) e está envolvido na replicação, ativação transcricional de genes virais e encapsidação do genoma viral. O DNA-B codifica duas proteínas de movimento, Movement Protein MP (BC1) e Nuclear Shuttle Protein NSP (BV1), ambas requeridas para o estabelecimento de uma infecção sistêmica. NSP transporta o DNA viral entre o núcleo e o citoplasma e então atua cooperativamente com MP para transportar o DNA viral de célula-a-célula através da parede celular. A localização de NSP e seu papel proposto no movimento célula- a-célula do DNA viral predizem que podem ocorrer interações com fatores do hospedeiro tanto no citoplasma quanto no núcleo. De fato, foi demonstrado que NSP interage com uma proteína receptora da membrana plasmática, designada NIK, e uma acetiltransferase nuclear. Através de ensaio de duplo híbrido, foi identificada, uma PERK quinase ( proline-rich extensin-like receptor protein kinase ) de Arabidopsis thaliana que interage especificamente com NSP de CaLCuV e, também de geminivírus que infectam tomate, a qual foi designada NsAK ( NSP-associated kinase ) e é estruturalmente organizada em um domínio N-terminal rico em prolina seguido de um segmento transmembrana e de um domínio C-terminal de serina/treonina quinase. A proteína viral interagiu estavelmente com versões defectivas do domínio de quinase de NsAK, mas não com a enzima potencialmente ativa em um ensaio de ligação in vitro. NsAK traduzida in vitro aumentou o nível de fosforilação de NSP, indicando que NSP atua como substrato de NsAK. Estes resultados demonstram que NsAK é uma autêntica serina/treonina quinase e sugerem elo funcional para a formação do complexo NSP-NsAK. Esta interpretação foi corroborada por ensaios de infectividade in vivo, demonstrando que a perda de função de NsAK reduz a eficiência da infecção por CaLCuV e atenua o desenvolvimento dos sintomas. Estes dados implicam NsAK como um contribuidor positivo para a infecção por geminivírus e sugerem que NsAK pode regular a função de NSP.
5

Identificação de uma via de sinalização de defesa antiviral mediada por um receptor de membrana do tipo sinase (NIK) através da interação com proteína NSP de geminivírus / Identification of a receptor-like kinase (NIK) mediated antiviral defense signaling pathway through interaction with geminivirus nuclear shuttle protein, NSP

Santos, Anésia Aparecida dos 17 July 2007 (has links)
Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-06-14T11:23:47Z No. of bitstreams: 1 texto completo.pdf: 947659 bytes, checksum: e40a84800499bceebcf0b0b2051d2265 (MD5) / Made available in DSpace on 2016-06-14T11:23:47Z (GMT). No. of bitstreams: 1 texto completo.pdf: 947659 bytes, checksum: e40a84800499bceebcf0b0b2051d2265 (MD5) Previous issue date: 2007-07-17 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Geminivírus constituem um grupo de vírus com genoma composto de DNA de fita simples que se replicam no núcleo de células do hospedeiro através de um intermediário dupla fita, podendo ser constituídos por um genoma mono ou bi-segmentado. O transporte do DNA viral do núcleo para o citoplasma de geminivírus bi-segmentados requer a proteína viral designada NSP, Nuclear Shuttle Protein (BV1). A localização de NSP e seu papel proposto no movimento célula-a-célula do DNA viral predizem que podem ocorrer interações com fatores do hospedeiro tanto no citoplasma quanto no núcleo. Inicialmente foi demonstrado que a proteína NSP de geminivírus que infecta Arabidopsis Cabbage leaf Curl Virus (CaLCuV) interage com receptores cinase (RLK) contendo repetições ricas em leucina (LRR) designadas NIK (NSP-Interacting Kinase). A interação NSP-NIK foi mapeada em NIK1 e ocorre através de uma região de 81 resíduos de aminoácidos do domínio cinase (aa 422-502) que compreende o potencial sítio ativo ser/tre cinase (subdomínio VIbHrDvKssNxLLD) e a alça de ativação (subdomínio VII-DFGAk/rx, mais subdomínio VIII GtxGyiaPEY). A proteína comportou-se como um autêntico receptor cinase, sofrendo autofosforilação in vitro. Sendo, entretanto, a atividade cinase inibida pela proteína NSP. A fim de analisar o papel biológico da interação NSP-NIK, ensaios de infecção foram realizados em plantas contendo alelos nulos para o gene NIK1. Estes resultados demonstraram que a inativação dos alelos NIK1 e NIK3 aumentou a suscetibilidade à infecção causada pelo CaLCuV. Dada a sobreposição do domínio de interação com NSP com domínios regulatórios, foram realizados estudos bioquímicos através de mutagênese sítio dirigida em NIK1. A fim de mapear os sítios envolvidos na ativação da fosforilação de NIK1, o resíduo Thr-474 na alça de ativação foi substituído para resíduos de Ala, Asp ou Glu. Além disso, os resíduos Thr-468, Thr-469 e Ser-465 foram trocados por Ala. Foi demonstrado que a proteína receptora NIK1 exibe um padrão complexo de sítios de fosforilação, que agem independentemente em reações de transfosforilação e fosforilação de substratos. O resíduo de Thr-474 possui um papel central na ativação da proteína cinase, uma vez que os mutantes T474A e T474E apresentaram baixas atividades de auto e fosforilação do substrato. Similarmente, substituição do resíduo Gly-473 por Val juntamente com substituição de Thr-474 por Ala aboliu a autofosforilação e a fosforilação do substrato, sugerindo que, esta mutação acarreta modificações estruturais da alça de ativação que promovem impedimentos estéricos. Em contraste, a substituição dos resíduos Thr-469 e Ser465 por alaninas não causou impacto acentuado na autofosforilação, mas aumentou a atividade de fosforilação do substrato. Provavelmente, fosforilação desses resíduos provocam um efeito inibitório na atividade cinase. Além disso, foram conduzidos experimentos de complementação em A. thaliana nocautes para NIK. Complementação de NIK1 restaurou o fenótipo selvagem com a diminuição da suscetibilidade ao vírus. Em contraste, a expressão de NIK1 mutante com o domínio cinase inativo não reverteu o fenótipo do nocaute nik1, mantendo a elevada taxa de infecção. Estes resultados suportam o argumento de que o domínio cinase de NIK1 medeia uma via de sinalização que culmina em uma resposta de defesa. / Geminiviruses are small, single-stranded DNA viruses that replicate through doublestranded DNA intermediates in the nuclei of their plant hosts and can be mono or bipartite. The transport of bipartite viral DNA from the nucleus to the cytoplasm requires the viral protein NSP, and the nuclear shuttle protein NSP (BV1), both required for systemic infection. The localization of NSP and its proposed role in cell-to-cell movement of the viral DNA predict that interactions with host factors may occur in both the cytoplasm and the nucleus. Initially we have demonstrated that the NSP from an Arabidopsis-infecting geminivirus, Cabbage leaf Curl Virus (CaLCuV) interacts with a leucine rich repeat (LRR) receptor like kinases (RLK) designated NIK (NSP-Interacting Kinase). The NSP-NIK interaction occurs in NIK1 through an 81 amino acid region of the kinase domain (aa 422502) that encompasses the putative active site for ser/thr kinases (sub-domain VIbHrDvKssNxLLD) and the activation loop (sub-domain VII-DFGAk/rx, plus subdomain VIII -GtxGyiaPEY).The protein behaved like authentic receptor kinase undergo autophosphorylation in vitro. However, NSP protein inhibits the kinase activity. To unravel the biological significance of the NSP-NIK interaction we have selected nik null alleles for infection assays. Inactivation of NIK1 and NIK3 alleles enhanced the susceptibility to geminivirus infection. Given the overlap of the NSP-interacting domain with regulatory domains for kinase activity, we focused on site-directed mutagenesis studies on NIK1 To map the phosphorylation sites involved in activation of NIK1, we have replaced Thr-474 in the activation loop by Ala, Asp or Glu residues, whereas Thr-468, Thr-469 and Ser 465 were replaced by Ala. We found that NIK1 exhibits a complex pattern of phosphorylation sites that function independently in auto- and in substrate phosphorylation. The Thr-474 residue seems to play a pivotal role in the activation of the kinase protein, since the mutants T474A and T474E exhibited low auto- and substrate phosphorylation activities. Furthermore, the replacement of Gly-473 by Val in addition to Thr-474 by Ala abolished autophosphorylation and phosphorylation of substrate, sugesting that this mutation promotes a structural rearrangement of the A-loop that compromises activity. In contrast, the replacement of Thr469 and Ser-465 for alanines did not impact autophosphorylation significantly, but increased substrate phosphorylation activity. Possibly the phosphorylation of these residues impairs the kinase activity. In addition, we conducted complementation experiments in the nik1 genetic background. NIK1 expression in nik1 complemented the mutant and restored the wild type phenotype, with decreased virus susceptibility. In contrast, an inactive kinase domaincontaining NIK1 mutant did not reverse the enhanced susceptibility phenotype of the knockout lines and kept a high infection rate. These results are consistent with a model in which the kinase domain of NIK mediates a signaling pathway that culminates in antiviral defense.
6

Análise funcional da via de sinalização antiviral mediada por NIK em tomateiro / Functional analysis of the NIK-mediated antiviral signaling in tomato

Apfata, Jorge Alberto Condori 18 February 2010 (has links)
Made available in DSpace on 2015-03-26T13:36:45Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2928675 bytes, checksum: b8457e10b48f36e111d09ef311ae3d5a (MD5) Previous issue date: 2010-02-18 / The begomovirus NSP (nuclear shuttle protein) facilitates the transport of viral DNA from the nucleus to the cytoplasm and cooperates with the movement protein MP to promote the translocation of viral DNA to the adjacent, uninfected cells through plasmodesmata. NSP interacts with members of the LRR-RLK ( leucine-rich repeat receptor like kinase ) family, designated NIKs ( NSP-Interacting Kinase ). Binding of NSP to the activation loop of NIK inhibits kinase activity and hence the viral protein suppresses receptor autophosphorylation and defense responses. Mutagenesis assays in the activation loop of NIK have demonstrated that the threonine 474 residue is phosphorylated in vitro and plays a crucial role in the kinase activity that is required for signaling. Replacement of Thr-474 with aspartate produces the T474 mutant, which exhibits constitutive activation, enhanced substrate phosphorylation activity and less inhibitory effect by NSP binding. The goal of this investigation was to analyse the NIK kinase domain in defense responses against begomovirus in tomato. The NIK mutant T474D cDNA was placed under the control of 35S promoter into a binary vector for plant transformation (35S-AtNIK-T474D). Primary transformants were selected by PCR and the expression of the transgene was confirmed by normal and quantitative RT- PCR in independently transformed lines. NIK and NIK-T474D overexpression in tomato plants affected the overall developmental performance of transgenic lines, which display elongated stems and a root system less developed. These phenotypes were consistent with a cross-communication between the NIK-mediated antiviral signaling and developmental signaling pathways. Infectivity assays were carried out in AtNIK- and AtNIK-T474D-overexpressing lines, with the virus ToYSV-[MG-Bi2]. Overexpression of super active AtNIK-T474D altered the infection rate by ToYSV, and interfered in symptom development. As compared to untransformed plants and NIK- overexpressing 35S-AtNIK1-6 transgenic lines, independent transgenic AtNIK-T474D lines displayed lower infection rate and attenuated symptoms. These results confirmed in planta the essential role for phosphorylation of the Thr-474 residue for NIK function and underlined the possibility for the development of more efficient tolerance strategies against geminiviruses. / A proteína NSP de begomovírus facilita o transporte do DNA viral do núcleo para o citoplasma e coopera com a proteína de movimento MP para promover o transporte do DNA viral às células adjacentes não infectadas através dos plasmodesmas. A proteína NSP interage com membros da família LRR-RLK ( leucine- rich repeat receptor like kinase ), designados NIK ( NSP-Interacting Kinase ). A ligação de NSP na alça de ativação de NIK inibe a atividade quinase, e conseqüentemente, a proteína viral inibe a atividade de autofosforilação desses receptores e sua atividade de defesa antiviral. Estudos de mutagênese na alça de ativação de NIK demonstraram que o resíduo Treonina 474 é fosforilado in vitro e exerce uma função crucial para atividade de quinase que é requerida para sinalização antiviral. Mutação no resíduo de Thr-474 para aspartato resulta no mutante T474D que exibe ativação constitutiva, atividade de fosforilaçao do substrato aumentada e menor efeito inibidor de NSP. Este trabalho teve como objetivo caracterizar o domínio quinase de NIK na resposta de defesa antiviral em tomateiros. Tomateiros foram transformados com a construção que codifica para NIK super ativa (35S-AtNIK-T474D). Os transformantes primários foram selecionados por PCR e a expressão do transgene em linhagens independentes foi confirmada por RT-PCR normal e em tempo real. A super expressão da NIK1 e NIK- T474D super ativa em tomateiros promoveu um alongamento de entrenós, mas afetou negativamente o desenvolvimento do sistema radicular, demonstrando uma possível comunicação cruzada entre a via de sinalização antiviral mediada por NIK e vias de sinalização de desenvolvimento. Experimentos de infectividade foram conduzidos em linhagens transgênicas superexpressando AtNIK ou AtNIK-T474D, utilizando o vírus ToYSV-[MG-Bi2]. Super expressão de NIK super ativa alterou a taxa de infecção por ToYSV e interferiu no desenvolvimento dos sintomas. Comparado com as plantas não transformadas e a linhagem transgênica 35S-AtNIK1-6 superexpressando NIK normal, a taxa de infecção foi inferior e os sintomas mais atenuados em linhagens transgênicas independentes superexpressando AtNIK-T474D. Estes resultados confirmam in planta o papel essencial da fosforilação do resíduo de Treonina 474 de NIK e indicam a possibilidade de se desenvolverem estratégias de tolerância a geminivirus mais eficientes.
7

Vývoj personálního managementu ve firmě NSP / Personal management development in company NSP

Vyshnevska, Olha January 2008 (has links)
This work is about personal management in ukrainian branch of the american company Nature’s Sunshine Products (NSP). It provides analysis of its current situation and contains suggestions to develop personal management in the company, which should help to increase its effectiveness.
8

Insights into regulatory mechanisms of the NIK-mediated antiviral defense: new components and the molecular bases of the defense / Introspecções sobre os mecanismos regulatórios da via de sinalização antiviral mediada por NIK: novos componentes e bases moleculares da defesa

Machado, João Paulo Batista 20 July 2015 (has links)
Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2015-11-04T08:18:47Z No. of bitstreams: 1 texto completo.pdf: 7981213 bytes, checksum: aeec0f7b21a6f76f66efa6e3304727b3 (MD5) / Made available in DSpace on 2015-11-04T08:18:48Z (GMT). No. of bitstreams: 1 texto completo.pdf: 7981213 bytes, checksum: aeec0f7b21a6f76f66efa6e3304727b3 (MD5) Previous issue date: 2015-07-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A proteína NIK (NSP-interacting kinase), identificada por interagir com a proteína NSP (nuclear shuttle protein) de geminivírus, apresenta características estruturais, bioquímicas e biológicas condizentes com um autêntico receptor cinase envolvido na resposta de defesa à infecção por geminivírus. A ativação deste receptor imune resulta na fosforilação da proteína ribossomal L10 (RPL10) e na subsequente relocação nuclear desta proteína ribossomal. Apesar dos avanços obtidos com a identificação de RPL10, outras conexões moleculares que ligam a ativação de NIK à resposta antiviral ainda são desconhecidas, bem como a natureza deste mecanismo de defesa. Nesta investigação, foi identificado um novo componente efetor downstream da via de sinalização mediada por NIK, um fator de transcrição denominado LIMYB (L10-Interacting Myb domain-containing protein), isolado pela sua capacidade de interagir com RPL10 pelo sistema de duplo híbrido em leveduras. Ensaios de co-imunoprecipitação e de complementação de fluorescência bimolecular (BiFC) mostraram que o complexo RPL10-LIMYB ocorre estavelmente na planta, mais precisamente no núcleo das células vegetais. Estudos de caracterização funcional mostraram que LIMYB atua como um autêntico fator de transcrição, ligando-se ao promotor e inibindo a expressão de genes de proteínas ribossomais. Estes resultados sugerem que o mecanismo de defesa antiviral mediado por NIK baseia-se na supressão da tradução do hospedeiro. Para examinar esta hipótese, inicialmente foi avaliado os níveis de tradução em linhagens de tomate superexpressando um mutante superativo de AtNIK1 (T474D). Os resultados mostraram que as linhagens transgênicas apresentaram menor acúmulo de proteínas recentemente sintetizadas quando comparadas com plantas WT. Posteriormente, as linhagens de tomate superexpressando T474D foram infectadas com duas espécies de begomovírus altamente divergentes, ToYSV (Tomato yellow spot virus) e ToSRV (Tomato severe rugose virus). As linhagens transgênicas apresentaram sintomas atenuados ou foram assintomáticas. Estas observações foram associadas com um atraso na infecção viral, com taxas de infecção menores e com a redução no acúmulo de DNA viral em folhas sistêmicas infectadas. Apesar do fenótipo de tolerância exibido pelas linhagens superexpressando T474D e dos menores índices de síntese proteica, estas linhagens não apresentaram diferenças no desenvolvimento, no desempenho fisiológico e nas características horticulturais quando comparadas com plantas WT ou com linhagens superexpressando AtNIK1. Finalmente, foi determinado se a redução nos níveis de tradução global do hospedeiro causado pela superexpressão de T474D poderia prejudicar a síntese de proteínas virais. Para isto, frações polissomais foram isoladas a partir de linhagens WT e T474D infectadas com ToYSV e a presença de mRNA viral foi examinada nestas frações. Os resultados mostraram uma menor associação do mRNA que codifica a proteína do capsídeo viral nas frações de polissomos de linhagens T474D quando comparadas àquelas de linhagens não transformadas. Coletivamente, estes resultados indicam que begomovírus não são capazes de manter altos níveis de tradução de mRNA virais nas linhagens superexpressando o mutante T474D, indicando que a supressão global da síntese de proteínas, identificada nestes genótipos, pode proteger eficientemente as células contra a infecção por estes vírus. Entretanto, estudos da variação global na expressão gênica de plantas nik1 alelos nulos mostraram que a perda da função de NIK1 promoveu a indução de componentes do hub principal da sinalização a brassinosteróide e de hubs envolvidos na sinalização ao ácido salicílico e na imunidade antibacteriana. Estes resultados sugerem que NIK1 pode funcionar como um regulador negativo em vias de sinalização de desenvolvimento e imunidade, apesar de sua propriedade antiviral. / The NSP-interacting kinase (NIK) protein, identified through interaction with the geminivirus nuclear shuttle protein (NSP), displays structural, biochemical and biological characteristics consistent with an authentic receptor kinase involved in defense response against geminivirus infection. The activation of this immune receptor leads to phosphorilation of the ribosomal protein L10 (RPL10) and in the subsequent nuclear relocation of this ribosomal protein. Apart from the identification of RPL10 as a downtream component of the defense signaling, others molecular connections that link the NIK activation to the antiviral response, as well as the nature of this defense mechanism, remain to be determined. In this investigation, a new downstream effector component of the NIK-mediated signaling pathway, a transcription fator designated LIMYB (L10-Interacting Myb domain-containing protein), was identified by its capacity to interact with RPL10 through yeast two-hybrid system. Co-immunoprecipitation and bimolecular fluorescence complementation assays showed that RPL10-LIMYB complex occurs stably in the plant, specifically in the nucleus of plant cells. Functional characterization studies showed that LIMYB acts as an authentic transcription fator, binding to and inhibiting expression of ribosomal protein promoters. These results suggest that NIK-mediated antiviral defense mechanism is based on host translation suppression. To examine this hypothesis, the translation levels in tomato lines overexpressing the constitutively active mutant of AtNIK1 (T474D) was initially assessed. The results demonstrated that transgenic lines had lower accumulation of newly synthesized proteins when comparated to WT plants. Subsequently, T474D-overexpressing tomato lines were infected with two highly divergent begomovirus species, ToYSV (Tomato yellow spot virus) and ToSRV (Tomato severe rugose virus). The transgenic lines either displayed attenuated symptons or were asymptomatic. These findings were associated with delay in viral infections, lower infection rates and reduction in viral DNA accumulation in systemically infected leaves. Despite the tolerance phenotype and lower rates of protein synthesis displayed by T474D-overexpressing lines, no difference in the development, physiological performance and horticultural traits was observed between T474D-overexpressing and WT or AtNIK1-overexpressing lines. Finally, whether the reduction in overall levels of host translation caused by overexpression of T474D could affect the viral proteins synthesis was examined. For this purpose, polysomal fractions were isolated from WT and T474D lines infected with ToYSV and examined for the presence of viral mRNA. The results showed lower association of mRNA encoding viral capsid protein at the polysomes fractions of T474D lines when comparated to that of untransformed lines. Collectively, these results indicate that begomovirus are not able to maintain high levels of viral mRNA translation into T474D-overexpressing lines, indicating that the global suppression of the protein synthesis identified in these genotypes may efficiently protect cells against infection by these virus. However, studies of global changes in gene expression of nik1 null alleles revealed that loss of NIK1 function promoted induction of components of the main brassinosteroid signaling hub and of hubs involved in salicylic acid signaling and antibacterial immunity. These results suggest that NIK1 may function as a negative regulator in development and immunity signaling pathways, despite its antiviral property.
9

Evaluation of the Soul City HIV and AIDS social intervention programme for the youth in the Northern Cape South Africa

Le Tape, Andre Rhyno January 2017 (has links)
The goal of the study was to evaluate the content, implementation and applicability of the Soul City social intervention programme (SCI programme) about HIV and AIDS targeted at the youth in the Northern Cape from an ecosystems perspective. The goal of this study was achieved through the realisation of the objectives of the study. The objectives of the study were: To describe the phenomenon of HIV and AIDS among the youth in the Northern Cape, South Africa from an ecosystems perspective; to describe the NSP 2012-2016 and the Provincial Strategic Plan (PSP) for HIV and AIDS in South Africa; to describe and critically analyse the SCI programme's focus on the youth from the ecosystems perspective; to evaluate the content of the SCI programme for the youth with regard to HIV and AIDS in the Northern Cape in the context of the NSP 2012-2016 on HIV and AIDS from the field workers' perspective; to evaluate the implementation of the SCI programme for the youth on HIV and AIDS in the Northern Cape in the context of the NSP 2012-2016 on HIV and AIDS from the perspective of the youth as service users, and lastly, to provide guidelines for the content, applicability, implementation, monitoring and evaluation of the SCI programme for the youth with regard to HIV and AIDS in the context of the NSP 2012-2016, in order to enhance efforts to mitigate the impact of HIV and AIDS among the youth in the Northern Cape. Furthermore, a mixed-methods research approach was adopted to achieve the research goal. The quantitative and qualitative findings are described in Chapters 6 and 7 respectively. Triangulation, as mixed-method design, was utilised in this study. This enabled the researcher to produce complete and well-validated conclusions. The method of data collection for the part of the study about the youth was a group-administered questionnaire. For the qualitative part of this study, semi-structured interviews, with an interview schedule, were utilised to collect data related to the contents, applicability, implementation, monitoring and evaluation of the SCI programme from trained field workers working in the youth sector and specialising in HIV and AIDS. The quantitative data was analysed using both descriptive and association statistical analyses. In the present study, the researcher strived to ensure a high degree of face validity by allowing experts in the field, for example, social workers practising in the field of HIV and AIDS, to scrutinise the research instrument as part of the pilot test. The questionnaire was piloted with 20 youths to enhance both face and content validity further. In the current study, an acceptable degree of reliability was prioritised and therefore a Cronbach alpha coefficient of 0.70 for all categories of the questionnaire was sought. The qualitative data of the semi-structured interviews with Soul City programme implementers was analysed using thematic analysis. An independent reviewer reviewed the theme generation and analysis to ensure consistency or the interrater reliability of the findings. This aided the researcher to identify patterns or themes from direct quotations and to provide rich data representation. Verbatim quotations from the interviews were used to support the themes. To ensure data trustworthiness, a high premium was placed on credibility, transferability, conformability and dependability. Analyses of three different sources of data, namely the literature review, the youth programme attendees/recipients and interviews with Soul City field workers were undertaken to answer the following research question. "To what extent is the content and implementation of the Soul City social intervention programme applicable to the youth in the Northern Cape?" Subsequently, the sub-question of the study was: "Does the Soul City social intervention programme take the different levels of the ecosystems perspective into account regarding programme content and implementation?" Several key findings were made in the quantitative part of the study, with nine sections of the questionnaire which focussed on: the Biographic details of respondents; Objectives of the Soul City programme for the youth in the Northern Cape; Applicability and relevance of the content of the Soul City Programme; Knowledge gained through attending Soul City; Attitudinal change; Programme delivery; Programme content; Programme facilitation methods and general aspects. Key findings were that there was no statistical association found between any of the variables in most sections of the questionnaire except for combinations of five questions in sections D and G. There was a statistical association found with regard to age where the respondents indicated that the SCP contributed to them achieving their personal life goals. Also in Section D there was a statistical association found where the respondents could see the impact of the SCP on their lives. There was a statistical association found between where respondents indicated that the SCP should focus on ways/strategies to fight poverty in their communities and also when they indicated that the SCP should focus on involving important people/stakeholders such as youth leaders. Lastly, there was a statistical association found between where the respondents indicated that the capacity of the youth in the community to fight the further spread of HIV and AIDS could be built by visiting the community. From an ecosystems perspective, the SCP programme appeared to be influenced by or aligned to micro-, meso-, exo- and macrolevel factors with varying degrees of success and focus areas. The programme's exolevel focus appeared to be more prominent and to a lesser degree the macro- and microlevels. The research found that the SCP is relatively effective regarding programme content and facilitation methods albeit to a limited degree. Furthermore, what was repeatedly clear was a need for the SCP's programme continuation and sustainability, because adequate effort had not been made for this despite the programmes' apparent value when it was operational. / Thesis (DPhil)--University of Pretoria, 2017. / Social Work and Criminology / DPhil / Unrestricted
10

Innovation Among Nutrient Service Providers in the Midwest

DePrator, Francesca Victoria 19 October 2018 (has links)
No description available.

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