Carbon and nitrogen stocks in soil under castor bean in the semi-arid Caatinga of Brazil

Grande parte da produção brasileira de mamona encontra-se no Nordeste, como opção de cultura para a região semiárida no bioma Caatinga. O objetivo deste estudo foi avaliar as alterações nos estoques de C e N devido à mudança de uso do solo de vegetação natural para o cultivo de mamona no bioma Caatinga. Este trabalho foi realizado na Fazenda Floresta, no município de Irecê, no centro-norte baiano. O clima da região é do tipo BSwh (Köppen) - clima semiárido de altitude. O solo foi classificado em Latossolo Vermelho de textura argilosa. As situações avaliadas foram: três áreas cultivadas com mamona com diferentes tempos de implantação: (i) com 10 anos, (ii) com 20 anos e (iii) com 50 anos; e uma área de referência (vegetação nativa de Caatinga) contígua às situações avaliadas. Os estoques de C e N foram determinados em amostras de solo coletadas em cinco minitrincheiras, nas camadas de 0-5, 5-10, 10-20 e 20-30 cm. Os resultados mostraram que o constante aporte de resíduos vegetais na Caatinga promoveu a manutenção dos estoques de C (90 Mg ha-1) e N (10 Mg ha-1) para a camada de 0-30 cm. A mudança de uso da terra para o cultivo da mamona ocasiona redução em aproximadamente 50 % nos estoques de C e N do solo em relação à vegetação nativa nos primeiros 10 anos de implantação da cultura. A meia-vida da matéria orgânica do solo (MOS) calculada para essa situação na região do semiárido foi de 4,7 anos. O fator de emissão de C do solo, devido à mudança de uso da terra após 20 anos, conforme proposto pelo método do IPCC (2006), foi de 2,47 Mg C ano-1. Por meio do conjunto dos resultados, observa-se a fragilidade do solo do bioma Caatinga no que se refere à perda de MOS devido à mudança de uso da terra

Bacteria from tropical semiarid temporary ponds promote maize growth under hydric stress.

World climate change has triggered soil water stress and imposed limitations on agricultural production. Plant growth-promoting bacteria (PGPBs) have been an efficient strategy to improve the biological supply and growth of plants under distinct abiotic stress conditions. We hypothesized that the soils from a temporary pond may harbor PGPBs with potential strains which increase maize tolerance to water deficit. We studied rhizosphere and bulk soil of Mimosa bimucronata in a temporary pond from semiarid Northeast Brazil to access strains with characteristics to promote plant growth and mitigate abiotic stress for maize crop. We isolated 355 bacterial isolates, from which 96 were selected based on the morphophysiological characterization to assess IAA production (42 % produced over 50 ug mL-1 of IAA), calcium phosphate solubilization (with one isolate achieving medium IS), biofilm and exopolysaccharides production (66 % and 98 % of isolates, respectively). Based on these mechanisms, the 30 most promising bacterial isolates were selected to assess biological nitrogen fixation (74 % of the isolates showed nitrogenase activity greater than 20 C2H4.h-1.mg-1), ACC deaminase activity (80 % of isolates) and growth in medium with reduced water activity (8 % of isolates grew in medium with water activity (Aw) of 0.844). We sequenced the 16S rRNA gene from the seven most promising isolates in in vitro and in vivo assays, which were identified as Staphylococcus edaphicus, Bacillus wiedmannii, Micrococcus yunnanensis, Streptomyces alboflavus, Streptomyces alboflavus, Bacillus wiedmanni and Bacillus cereus. In vivo, eleven isolates and three bacterial consortia did not differ from the control with nutrient solution, for total leaf area and root dry mass of maize. S. alboflavus (BS43) had the best in vivo results, not differing from the control with nutrient solution. We highlight the unpublished potential of Staphylococcus edaphicus and Streptomyces alboflavus in promoting the growth of plants under water stress. In addition, it is the first report of bacteria isolated from a temporary pond in the Brazilian semiarid which promoting plant growth attributes and development

Links between plant and fungal communities across a deforestation chronosequence in the Amazon rainforest

Understanding the interactions among microbial communities, plant communities and soil properties following deforestation could provide insights into the long-term effects of land-use change on ecosystem functions, and may help identify approaches that promote the recovery of degraded sites. We combined high-throughput sequencing of fungal rDNA and molecular barcoding of plant roots to estimate fungal and plant community composition in soil sampled across a chronosequence of deforestation. We found significant effects of land-use change on fungal community composition, which was more closely correlated to plant community composition than to changes in soil properties or geographic distance, providing evidence for strong links between above- and below-ground communities in tropical forests. © 2014 International Society for Microbial Ecology All rights reserved

O processo de constituição de uma professora considerada inesquecivel

t: This research aims to analyze the mediators of the process of constitution of a teacher considered successful by students and peers. It is intended to identify and describe these mediators, as well the pedagogical practices of this teacher. This research aims to contemplate the following question: how it is constituted, and which practices of a teacher, regarded as an agent that, in addition to providing experiences related to the appropriation of knowledge, also brings students affectively positive content? The choice of this subject was organized and took place from previous experiences with the teacher in question. She was the teacher responsible for coordinating a Science Project (LEITE & FRACETTO, 2016) that aimed to guide scientific research in Middle School; moreover, through the researcher\u27s experiences of school and internship, it was possible to see through stances and speeches, that this subject is recognized by the school community as an excellent teacher, besides developing pedagogical practices with emphasis on Science content. So, this research uses the qualitative methodological approach, supported by the authors Lüdke& André (1986) and Bodgan&Biklen (1997), and the data collection procedure known as "recurrent interviews", characterized by Zanelli (1992) and Leite& Colombo (2006). It is in this context that this research has the intention to expose the process of constitution of a professional education in the light of the Historical-Cultural Theory of Vygotsky (1996, 1998a, 1998b, 1999, 2001, 2005), the Psychogenetic Theory of Wallon (1968, 1979, 1995), Leite\u27 studies (2002, 2005, 2006, 2012),and Fernandes (2014). It is concluded that the developed nucleus and subnucleus represent the significance of factors that may be related to the process of formation of that teacher, relating its constitution with the history of the subjective impact of her experiences, and also realizing a brief description of her pedagogical practices. It is hoped, therefore, that this task can be used to contribute to researches that aims to understand the universe of meanings of teacher formation, and help in the construction of subsidies that can be used to improve teaching and learning relations, emphasizing school management, from the studies of Sander (2007) and Garcia (1981), and public policies as essential for this process (FREITAS, 2012). Resum

Emotion and imagination in working with young children in early childhood education : an exploratory study based on Vygotsky's ideas

Orientadores: Lavínia Lopes Salomão Magiolino, Daniele Nunes Henrique SilvaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de EducaçãoResumo: Esta pesquisa se insere nas áreas da Psicologia e da Educação e tematiza a relação entre emoção e imaginação no desenvolvimento infantil, a partir das ideias de L. S. Vigotski. Objetivou-se, neste estudo, compreender e analisar indícios de processos desenvolvimentais que abrangem a emoção e a imaginação no trabalho com crianças muito pequenas, com enfoque em brincadeiras, dramatizações e contações de histórias. Num desdobramento desse objetivo mais geral, pretendeu-se também: 1. explorar indícios da relação entre emoção, imaginação e realidade por meio de atividades que envolveram brincadeira, contação de história e dramatização; 2. analisar situações empíricas que deram visibilidade à produção indicial do signo emocional comum; 3. refletir criticamente a respeito dos entraves para promoção de situações pedagógicas favoráveis à emergência de processos criadores no contexto educacional, bem como de suas implicações para o desenvolvimento da criança muito pequena. Metodologicamente, optou-se pela realização de uma pesquisa-ação-participativa, com videogravação de episódios elucidativos da temática investigada, a partir da análise microgenética dos dados. Para tanto, foram realizadas oito oficinas temáticas com uma turma de crianças de um ano e meio a três anos de idade, em uma instituição de educação infantil localizada em uma cidade do interior do estado de São Paulo. Essas oficinas envolveram ainda a professora e duas agentes de educação infantil. A análise do material focalizou a discussão conceitual dos seguintes aspectos: a) a função combinatória da imaginação em sua relação com a realidade e com a experiência da criança muito pequena; b) o processo de criação e de transformação do significado dos objetos a partir da interação criança-criança e criança-adulto; c) os indícios da relação entre imaginação e emoção no processo de imitação/criação infantil; d) a complexidade dos processos emocionais em sua relação com a imaginação e a realidade, considerando o papel central da significação nesse processo. As situações empíricas vivenciadas ao longo da pesquisa promoveram reflexões importantes acerca do contexto educacional e de sua relação com os processos desenvolvimentais das crianças investigadas. Destacou-se a postura ativa dos adultos na mediação das atividades realizadas nas interações entre crianças, tanto para incentivar quanto para coibir processos emocionais e imaginativos, tendo em vista a organização do trabalho pedagógico. A delimitação teórica sobre a temática, atrelada à investigação empírica, colaborou para o adensamento de reflexões no campo da educação e da psicologia, na medida em que apontam para processos desenvolvimentais complexos que envolvem a imaginação e a emoção na educação infantil e que precisam ser considerados para redimensionamento dos fundamentos, conceitos e práticas pedagógicasAbstract: This research is inserted in the areas of Psychology and Education focusing on the relationship between emotion and imagination in child development, based on the ideas of L. S. Vygotsky. This study aimed to understand and analyze evidence of developmental processes that involve emotion and imagination in working with very young children, focusing on play, dramatizations and storytelling. In an unfolding of this more general objective, the intention was also to: 1- explore evidence of the relationship between emotion, imagination and reality through activities that involved play, storytelling and dramatization; 2- analyze empirical situations that gave visibility to the index production of the common emotional sign; 3- reflect critically on the obstacles to the promotion of pedagogical situations favorable to the emergence of creative processes in the educational context, as well as their implications for the development of very young children. Methodologically, it was opted for conducting a participatory action-research, with video recording of explanatory episodes of the investigated theme, based on a microgenetic analysis of the data. For this purpose, eight thematic workshops were held with a group of children from one and a half to three years old, in a child education institution located in a city in the interior of the state of São Paulo. These workshops also involved the teacher and two child education agents. The analysis of the material focused on the conceptual discussion of the following aspects: a) the combinatorial function of the imagination in its relationship with reality and with the experience of the very young child; b) the process of creating and transforming the meaning of objects based on the child-child and child-adult interaction; c) evidence of the relationship between imagination and emotion in the child imitation / creation process; d) the complexity of emotional processes in their relationship with imagination and reality, considering the central role of meaning in this process. The empirical situations experienced throughout the research promoted important reflections about the educational context and its relationship with the developmental processes of the investigated children. It can be highlighted the active posture of adults in mediating the activities performed in the interactions between children, both to encourage and to restrain emotional and imaginative processes, with a view to organizing pedagogical work. The theoretical delimitation on the theme, linked to empirical research, contributed to the densification of reflections in the field of education and psychology, insofar as they point to complex developmental processes that involve imagination and emotion in education that need to be considered in order to resize the foundations, concepts and pedagogical practicesMestradoEducaçãoMestra em Educaçã