Mutagenesis by hydrogen peroxide treatment of mammalian cells: a molecular analysis

Hydrogen peroxide is an oxidizing agent which can be generated intracellularly either during normal metabolism or by treatment with external agents including solar UV radiation. Simian cells (CV-1) transfected with the SV40-based shuttle vector plasmid pZ189 have been treated with H2O2 and then incubated to allow repair and replication of the plasmid. The frequency of mutations at the supF locus of the recovered plasmid increases by a factor of up to four over the spontaneous value. The nucleotide changes associated with 100 spontaneous and 100 H2O2-induced mutants have been determined directly by sequencing a 150 bp fragment that includes the entire supF tRNA coding region. Deletions were observed in ∼45% of both the spontaneous and induced mutants, whereas single or multiple base changes arose in 68 and 57% of the induced and spontaneous mutants respectively. The spectrum of induced mutations is characterized by (i) the occurrence of deletions associated with base changes (16% of all mutants analysed) and (ii) small deletions of 3 bp and less (51% of all deletion mutants sequenced). Sixty-five per cent (15 out of 23) of all small deletions (spontaneous and induced) are associated with runs of between two and five identical bases and eight of them arise at a mutational ‘hotspot' region of five cytosines between bp 172 and 176. The majority (19 out of 30) of completely sequenced deletions observed in the spontaneous spectrum contain either (i) small (2-10 bp) direct repeat sequences that lie immediately outside one deletion terminus and immediately inside the second deletion terminus or (ii) small (2-3 bp) inverted repeat sequences lying immediately inside the two deletion termini. Most deletions that we have observed are therefore likely to arise as a consequence of specific aspects of DNA structur

Planning for the Protection of Industrial Land and Services in the Sustainable City - A Nelson, New Zealand Case Study

Industrial zoned land and industrial activities within cities are facing a number of challenges which could potentially see industry displaced from urban environments. Contributing to this is the inadequate coverage of industry in growth management strategies such as Smart Growth and the Compact City, which influence urban development and local planning legislation. The aim of this thesis was to confirm the increasing evidence that industrial activities remain vitally important to a city’s sustainable development and for ensuring the positive function of local economies. This was explored within the case study of Nelson, New Zealand, a region experiencing high levels of population and economic growth within a strictly limited land base. Industrial land is under increasing pressure with future supply expected to be exhausted within six years at the current rate of demand. Results of this research have confirmed the importance of industry within urban spaces and the need for tighter planning for the protection of industrial land and services if the city’s sustainable goals are to be achieved. Intensification was explored as a means by which industry can fit within smart growth strategies and can be reconceptualised to fit within the modern city. In addition, an industrial land supply method was developed as a practical starting point for local authorities to quantify future industrial land supply and also understand the complexity of issues relating to industrial sites and activities. Research enabled recommendations to be made which will assist planning and policy initiatives to ensure sustainable and more efficient industrial zone management

Visualizing and quantitating the spatiotemporal regulation of Ras/ERK signaling by dual-specificity mitogen-activated protein phosphatases (MKPs)

The spatiotemporal regulation of the Ras/ERK pathway is critical in determining the physiological and pathophysiological outcome of signaling. Dual-specificity mitogen-activated protein kinase (MAPK) phosphatases (DUSPs or MKPs) are key regulators of pathway activity and may also localize ERK to distinct subcellular locations. Here we present methods largely based on the use of high content microscopy to both visualize and quantitate the subcellular distribution of activated (p-ERK) and total ERK in populations of mouse embryonic fibroblasts derived from mice lacking DUSP5, a nuclear ERK-specific MKP. Such methods in combination with rescue experiments using adenoviral vectors encoding wild-type and mutant forms of DUSP5 have allowed us to visualize specific defects in ERK regulation in these cells thus confirming the role of this phosphatase as both a nuclear regulator of ERK activity and localization.</p

A promoção da capacidade absortiva dos recursos de cluster e o local buzz através das associações de produtores da caprinocultura no Cariri Paraibano

Purpose – This paper contributes to the literature on local buzz and the absorptive capacity of firms aiming the competitiveness of the local productive agglomerations. The associations of producers of goat's milk and derivatives of Cariri Paraibano were analyzed. They form a cluster of 881 partners and are responsible for the production of approximately 8,631 liters of goat milk per day. The research objective was to identify, based on the local buzz, the participants' awareness about the clustering benefits and the absorption of cluster resources.Design/methodology/approach – It used a qualitative methodology based on a case study. Various sources of evidence were used to guarantee the reliability of results. So, it performs triangulation of in-depth interviews, direct observation, and content analysis of documents.Findings – The results indicated the existence of knowledge about goat production, a similar level of absorptive capacity between the producer associations, and a degree of awareness of the advantages of being agglomerated. Also, findings evidenced external knowledge not absorbed by the producers that could be linked to the incompleteness of the association's role as cluster vectors.Originality/value – The sector dynamics depend on the organizations' view on the importance of information and its use in the operation of firms in order to increase their absorptive capacity.Proposta - Este artigo contribui para a literatura sobre local buzz e a capacidade absortiva das empresas visando a competitividade dos arranjos produtivos locais. Analisou-se as associações de produtores de leite de cabra e derivados do Cariri Paraibano que formam um aglomerado produtivo de 881 parceiros responsáveis pela produção de aproximadamente 8.631 litros de leite caprino por dia. O objetivo da pesquisa foi identificar a partir do local buzz a consciência dos participantes sobre os benefícios de integrarem este cluster e a absorção dos recursos do cluster.Desenho Metodológico - A metodologia aplicada é qualitativa, sendo um estudo de caso que realiza a triangulação de fontes de evidências, entrevistas em profundidade, observação direta e análise de conteúdo de documentos.Resultados - Os resultados indicaram a existência de conhecimento sobre a caprinocultura, similaridade no nível de capacidade absortiva entre as associações do cluster, e um grau de consciência das vantagens de estar aglomerado. Também indicaram que existem conhecimentos externos que não estão sendo absorvidos pelos produtores e que podem estar vinculados a incompletude do papel das associações como vetores do cluster.Originalidade - A dinâmica do setor depende da visão das organizações sobre a importância da informação e consequente, seu uso na operação das empresas a fim de ampliar a capacidade absortiva das mesmas

Avaliação clínica, ultra-estrutural e química de dentes que receberam selantes : estudo in vivo

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2013.O progresso científico na compreensão do processo carioso e o desenvolvimento dos materiais adesivos, possibilitou aos cirurgiões dentistas fazer mais que simplesmente remover tecido cariado. Este fato fez com que a principal preocupação dentro da odontologia nos últimos tempos tenha sido a pesquisa de meios e materiais que possam reduzir a ocorrência dessa enfermidade. Dentre as medidas mais utilizadas na prevenção da cárie em superfície oclusal está o selamento de fóssulas e fissuras. Neste contexto o objetivo deste estudo foi comparar a retenção clínica de selantes a base de ionômero de vidro e resina composta em fóssulas e fissuras de molares decíduos; avaliar a retenção dos dois materiais seladores por meio de microscopia eletrônica de varredura (MEV); bem como verificar os níveis de Cálcio (Ca), Fósforo (P) e Flúor (F) presentes no esmalte após a aplicação dos materiais. A presente pesquisa caracterizou um Ensaio Clinico Randomizado Split Mouth (boca dividida).Foram selecionadas 10 crianças com faixa etária entre 9 e 11 anos de idade, com indicação para aplicação de selantes em segundos molares inferiores decíduos. Os 20 dentes foram divididos em 2 grupos aleatórios, onde cada paciente recebeu o selante resinoso em um dente e o selante ionomérico no outro dente. Os espécimes foram submetidos a análise clínica e classificados quanto a presença do selante em: selante total, selante parcial e ausente, a mesma classificação foi utilizada para a análise por MEV. A medição dos elementos Ca, P e F foi realizada por meio da Espectometria de Energia Dispersiva (EDS). Os dados obtidos foram submetidos à análise estatística ao nível de significância de 5%. Os resultados relativos a avaliação clínica demonstraram que 100% dos selantes resinosos foram classificados como selante total, enquanto 40% dos selamentos com cimento de ionômero de vidro receberam a mesma classificação e 60% foram classificados como selante parcial. Contudo, a análise por MEV demonstrou que ambos os materiais apresentaram retenção semelhante à estrutura dentária (p=0,653). Com relação a troca iônica, verificou-se que os níveis dos íons Cálcio e Fósforo foram superiores no grupo Ionomérico com diferença significante entre os grupos (p=0,0136) e (p=0,0124) respectivamente. O estudo apresentou limitações para a aferição do íon Flúor. Os resultados demonstraram que o selante à base de cimento de ionômero de vidro mesmo após a perda parcial observada clinicamente, apresentou retenção semelhante ao material resinoso na análise por microscopia. Conclui-se que não houve diferenças estatísticas para avaliação da retenção entre os materiais estudados, mesmo após valores numericamente superiores de perda parcial observados clinicamente para o grupo ionomérico, sendo que os níveis dos íons Cálcio e Fósforo foram significativamente superiores neste grupo. ______________________________________________________________________________________ ABSTRACTScientific progress in understanding the carious process and the development of adhesive materials, enabled the dentists to do more than simply remove decayed tissue. This meant that the main concern in dentistry recently has been the research of means and materials that can reduce the occurrence of this disease. Among the most frequently used measures in prevention of caries in occlusal surface is the sealing of pits and fissures. Thus, the objective of this study was to compare the clinical retention of sealants based on glass ionomer and resin composite in pits and fissures of deciduous molars; to evaluate the retention of the two sealing materials by scanning electron microscopy (SEM), as well as checking levels Calcium (Ca), Phosphorus (P) and Fluoride (F) present in the enamel following application of the materials. This study featured a randomized clinical trial Split Mouth. Ten children with age between 9 and 11 years old , listed for application of sealants in deciduous lower second molars . The 20 teeth were divided into two random groups, where each patient received the resin sealant on one tooth and another tooth in glass ionomer sealant .The teeth were subjected to clinical examination and ranked as the presence of sealant: Sealant full, partial and missing sealant, the same classification was used for analysis by SEM. The measurement of calcium, phosphorus and fluoride elements was performed by through the EDS tool. Data were statistically analyzed at 5% significance level. The results of the clinical evaluation showed that 100% of resin sealants were classified as full sealant, while 40% of sealings with glass ionomer cement received the same rating and 60% were classified as partial sealant. However, analysis by scanning electron microscopy showed that both materials showed similar retention to tooth structure (p=0.653). Regarding to ion exchange, it was found that the levels of calcium and phosphorus ions were higher in the ionomer group with a significant difference between groups (p=0.0136) and (p=0.0124) respectively. The study presented limitations for the fluoride ion measurement. Results showed that the sealant based on glass ionomer cement even after the partial loss observed clinically, presented similar performance to resinous material by microscopy analysis of retention. It was concluded that there were no statistical differences for retention evaluation of the materials studied , even after numerically higher values of partial loss observed clinically for the ionomer group , and the levels of calcium and phosphorus ions were significantly higher in this group

As interações entre leitores na seção The long read do The Guardian : entre a política editorial de moderação e a participação das audiências ativas

Orientador(a): Prof(a). Dr(a). Claudia QuadrosDissertação (mestrado) - Universidade Federal do Paraná, Setor de Artes, Comunicação e Design, Programa de Pós-Graduação em Comunicação. Defesa : Curitiba, 16/04/2020Inclui referências: p. 134-138Resumo: As interações entre leitores e sites dos jornais impressos ganharam novos contornos ao longo das últimas duas décadas. Esta pesquisa pretende compreender como é feita a condução e a articulação da comunidade on-line de leitores em um dos maiores jornais do mundo, o britânico The Guardian. O foco está nas interações entre leitores da seção de jornalismo de profundidade (intitulada The long read) no site e de que forma essas participações são estimuladas e conduzidas pelo jornal para conquistar e manter a audiência ativa. Propõe-se identificar os tipos de interação; o estudo da política editorial de moderação do jornal; a demonstração de como ocorre a apropriação do espaço de comentários pelos leitores e a construção dialógica coletiva. A base teórica deste trabalho articula conceitos como a dinâmica das interações (THOMPSON, 2008/2019; FRAGOSO, 2001), audiências ativas (MASIP et al., 2015), política editorial de moderação (DOMINGO, 2015) e jornalismo long-form (LONGHI; WINQUES, 2015). Para esta análise foram escolhidas as reportagens long read eleitas entre as melhores do ano pelo The Guardian. Foram selecionados os textos que tiveram maior número de comentários de leitores - um texto por ano (entre 2015 a 2017). A avaliação dos comentários foi realizada por meio de Análise de Conteúdo, de Laurence Bardin (2016). Para tanto, foram selecionadas as três caixas de discussão por texto/ano com o maior número de comentários, entre as dez que tiveram mais recomendações pelos leitores. Para esta análise foram computados 400 comentários. A partir da análise desses materiais, abre-se a possibilidade de compreensão sobre o quanto a articulação da política editorial de moderação do The Guardian repercute nos níveis de engajamento e lealdade e na natureza da interação entre os leitores na seção The long read. Palavras-chave: Jornalismo digital. Audiências ativas. Política editorial de moderação. Interação. The Guardian.Abstract: Interactions between readers and websites of print newspapers have gained new contours over the past two decades. This research aims to understand how the online reader community is conducted and articulated in one of the largest newspapers in the world, The Guardian. The focus is on interactions between readers of the indepth journalism section (titled The Long Read) on the site and how these engagements are stimulated and led by the newspaper to engage and keep the audience active. It is proposed to identify the types of interaction; the study of the newspaper's moderation editorial policy; the demonstration of how readers' appropriation of the commentary space occurs and the collective dialogical construction. The theory articulates concepts such as the dynamics of interactions (THOMPSON, 2008/2019; FRAGOSO, 2001), active audiences (MASIP et al., 2015), moderation editorial policy (DOMINGO, 2015) and long-form journalism (LONGHI; WINQUES, 2015). For this analysis were chosen long read reports voted among the best of the year by The Guardian. We selected the texts that had the highest number of reader comments - one text per year (from 2015 to 2017). The commentaries are analysed using the methodological technique of Content Analysis, by Laurence Bardin (2016). For this, were selected the three discussion boxes per text/year with the highest number of comments, among the ten that had the most recommendations by readers. For this analysis, 400 comments were computed. From the analysis of these materials, it opens up the possibility of understanding how the articulation of The Guardian's moderation editorial policy impacts the levels of engagement and loyalty and the nature of interaction between readers in The long read section. Keywords: Digital journalism. Active audiences. Moderation editorial policy. Interaction. The Guardian

A search for an integrated peace framework for Angola : the case of Kuito-Bié and Viana.

Master of Social Science in Politics. University of KwaZulu-Natal, Pietermaritzburg 2016.The 2002 ceasefire agreement in Angola represented an unprecedented achievement as far as building peace is concerned. With the belligerents able to talk, the country had a great opportunity to embark on a full reconciliation process. However, the situation in the country is in the status of unresolvedness. The peace is still negative. There are no avenues for open dialogue for positive change. This thesis presents the various phases of the Angolan peace process, its shortcomings and success. Further, a suggestion for a full framework for Angola based on John Paul Lederach´s Integrated Framework for peacebuilding is given for the Angolan grassroots to embark on peace process starting from the bottom. The researcher selected 200 hundred respondents with experience of the war. One hundred from Kuito- Bié and the other hundred from Viana. Through snowball and purposive sampling participants were identified. Furthermore, the researcher interviewed with one member of MPLA, one from UNITA, one from the civil society and one from the Catholic Church. The results showed that the civil society is not satisfied with the current peace, and urges for a new era. Thus, Lederach´s peace structural framework fits well in Angola

Regulation of Caenorhabditis elegans p53/CEP-1–Dependent Germ Cell Apoptosis by Ras/MAPK Signaling

Maintaining genome stability in the germline is thought to be an evolutionarily ancient role of the p53 family. The sole Caenorhabditis elegans p53 family member CEP-1 is required for apoptosis induction in meiotic, late-stage pachytene germ cells in response to DNA damage and meiotic recombination failure. In an unbiased genetic screen for negative regulators of CEP-1, we found that increased activation of the C. elegans ERK orthologue MPK-1, resulting from either loss of the lip-1 phosphatase or activation of let-60 Ras, results in enhanced cep-1–dependent DNA damage induced apoptosis. We further show that MPK-1 is required for DNA damage–induced germ cell apoptosis. We provide evidence that MPK-1 signaling regulates the apoptotic competency of germ cells by restricting CEP-1 protein expression to cells in late pachytene. Restricting CEP-1 expression to cells in late pachytene is thought to ensure that apoptosis doesn't occur in earlier-stage cells where meiotic recombination occurs. MPK-1 signaling regulates CEP-1 expression in part by regulating the levels of GLD-1, a translational repressor of CEP-1, but also via a GLD-1–independent mechanism. In addition, we show that MPK-1 is phosphorylated and activated upon ionising radiation (IR) in late pachytene germ cells and that MPK-1–dependent CEP-1 activation may be in part direct, as these two proteins interact in a yeast two-hybrid assay. In summary, we report our novel finding that MAP kinase signaling controls CEP-1–dependent apoptosis by several different pathways that converge on CEP-1. Since apoptosis is also restricted to pachytene stage cells in mammalian germlines, analogous mechanisms regulating p53 family members are likely to be conserved throughout evolution