134 research outputs found
Caracterização dos quintais agroflorestais urbanos na cidade de Alta Floresta-MT
O presente estudo teve por objetivo caracterizar os quintais agroflorestais urbanos, no município de Alta Floresta-MT, Brasil. Foram entrevistados 30 mantenedores utilizando entrevistas semiestruturadas. Os quintais possuem área média de 1,28 ha. O tempo médio de ocupação dos quintais é de 15 anos. Nenhum informante soube responder o que é um quintal agroflorestal. As espécies vegetais nos quintais possuem diversas origens. A periodicidade da manutenção dos quintais é diária. As tratos culturas são poda, desbrota, adubação, controle de formigas e cupins. Utilizam-se adubos químicos e agrotóxicos para o controle de espécies espontâneas, de insetos e doenças. Há criação de animais, além da presença de animais silvestres. Observou-se heterogeneidade na caracterização dos quintais agroflorestais urbanos.This study aimed to characterize urban agroforestry gardens and the profile of the maintainers of these, in the municipality of Alta Floresta-MT, Brazil. Thirty maintainers were interviewed using semi-structured interviews. The gardens have an average area of 1.28 ha.
The average time of occupancy of the yards is 15 years. No informant could answer what is an agroforestry yard. Plant species in backyards have diverse origins. The frequency of maintenance of gardens is daily. Culture treatments are pruning, thinning, fertilization, ant control and termites. Chemical fertilizers and pesticides are used for the control of spontaneous species of insects and diseases. There are farm animals and the presence of wild animals. There was heterogeneity in the characterization of urban agroforestry yards.Eje A5: Sistemas de conocimientoFacultad de Ciencias Agrarias y Forestale
Caracterização dos quintais agroflorestais urbanos na cidade de Alta Floresta-MT
O presente estudo teve por objetivo caracterizar os quintais agroflorestais urbanos, no município de Alta Floresta-MT, Brasil. Foram entrevistados 30 mantenedores utilizando entrevistas semiestruturadas. Os quintais possuem área média de 1,28 ha. O tempo médio de ocupação dos quintais é de 15 anos. Nenhum informante soube responder o que é um quintal agroflorestal. As espécies vegetais nos quintais possuem diversas origens. A periodicidade da manutenção dos quintais é diária. As tratos culturas são poda, desbrota, adubação, controle de formigas e cupins. Utilizam-se adubos químicos e agrotóxicos para o controle de espécies espontâneas, de insetos e doenças. Há criação de animais, além da presença de animais silvestres. Observou-se heterogeneidade na caracterização dos quintais agroflorestais urbanos.This study aimed to characterize urban agroforestry gardens and the profile of the maintainers of these, in the municipality of Alta Floresta-MT, Brazil. Thirty maintainers were interviewed using semi-structured interviews. The gardens have an average area of 1.28 ha.
The average time of occupancy of the yards is 15 years. No informant could answer what is an agroforestry yard. Plant species in backyards have diverse origins. The frequency of maintenance of gardens is daily. Culture treatments are pruning, thinning, fertilization, ant control and termites. Chemical fertilizers and pesticides are used for the control of spontaneous species of insects and diseases. There are farm animals and the presence of wild animals. There was heterogeneity in the characterization of urban agroforestry yards.Eje A5: Sistemas de conocimientoFacultad de Ciencias Agrarias y Forestale
Extracellular VirB5 Enhances T-DNA Transfer from Agrobacterium to the Host Plant
VirB5 is a type 4 secretion system protein of Agrobacterium located on the surface of the bacterial cell. This localization pattern suggests a function for VirB5 which is beyond its known role in biogenesis and/or stabilization of the T-pilus and which may involve early interactions between Agrobacterium and the host cell. Here, we identify VirB5 as the first Agrobacterium virulence protein that can enhance infectivity extracellularly. Specifically, we show that elevating the amounts of the extracellular VirB5—by exogenous addition of the purified protein, its overexpression in the bacterium, or transgenic expression in and secretion out of the host cell—enhances the efficiency the Agrobacterium-mediated T-DNA transfer, as measured by transient expression of genes contained on the transferred T-DNA molecule. Importantly, the exogenous VirB5 enhanced transient T-DNA expression in sugar beet, a major crop recalcitrant to genetic manipulation. Increasing the pool of the extracellular VirB5 did not complement an Agrobacterium virB5 mutant, suggesting a dual function for VirB5: in the bacterium and at the bacterium-host cell interface. Consistent with this idea, VirB5 expressed in the host cell, but not secreted, had no effect on the transformation efficiency. That the increase in T-DNA expression promoted by the exogenous VirB5 was not due to its effects on bacterial growth, virulence gene induction, bacterial attachment to plant tissue, or host cell defense response suggests that VirB5 participates in the early steps of the T-DNA transfer to the plant cell
Rethinking non-traditional resistance at work : the case of the Indian Diaspora in Mauritius
Resistance at work can take many forms and this is reflected in the multiple ways it has been theorised in research. In this paper, I use postcolonial theory to analyse employee resistance in Mauritius. To do this, I deploy Homi Bhabha’s concepts of mimicry, ambivalence and hybridity to explore non-traditional forms of resistance among the Indian Diaspora working in the hotel industry. Using ethnographic research, I firstly look at its ‘home’-making practices as it is within the home that visions of community emerge (Bhabha, 1994) which could later influence behaviours at work. I argue that the Diaspora maintains connections with its ancestral roots via routine religious practices and language use while concomitantly resisting assimilation in the local context. The analysis is then extended to their workplace where further forms of non-traditional resistance are found to be enacted which are strongly influenced by the same values emerging at home
Endogenous antigen processing drives the primary CD4+ T cell response to influenza.
By convention, CD4+ T lymphocytes recognize foreign and self peptides derived from internalized antigens in combination with major histocompatibility complex class II molecules. Alternative pathways of epitope production have been identified, but their contributions to host defense have not been established. We show here in a mouse infection model that the CD4+ T cell response to influenza, critical for durable protection from the virus, is driven principally by unconventional processing of antigen synthesized within the infected antigen-presenting cell, not by classical processing of endocytosed virions or material from infected cells. Investigation of the cellular components involved, including the H2-M molecular chaperone, the proteasome and γ-interferon-inducible lysosomal thiol reductase revealed considerable heterogeneity in the generation of individual epitopes, an arrangement that ensures peptide diversity and broad CD4+ T cell engagement. These results could fundamentally revise strategies for rational vaccine design and may lead to key insights into the induction of autoimmune and anti-tumor responses
Rethinking non-traditional resistance at work: The case of the Indian Diaspora in Mauritius
Improving collection efforts to avoid loss of biodiversity: lessons from comprehensive sampling of lycophytes and ferns in the subtropical Atlantic Forest
An Anomalous Type IV Secretion System in Rickettsia Is Evolutionarily Conserved
Bacterial type IV secretion systems (T4SSs) comprise a diverse transporter family functioning in conjugation, competence, and effector molecule (DNA and/or protein) translocation. Thirteen genome sequences from Rickettsia, obligate intracellular symbionts/pathogens of a wide range of eukaryotes, have revealed a reduced T4SS relative to the Agrobacterium tumefaciens archetype (vir). However, the Rickettsia T4SS has not been functionally characterized for its role in symbiosis/virulence, and none of its substrates are known.Superimposition of T4SS structural/functional information over previously identified Rickettsia components implicate a functional Rickettsia T4SS. virB4, virB8 and virB9 are duplicated, yet only one copy of each has the conserved features of similar genes in other T4SSs. An extraordinarily duplicated VirB6 gene encodes five hydrophobic proteins conserved only in a short region known to be involved in DNA transfer in A. tumefaciens. virB1, virB2 and virB7 are newly identified, revealing a Rickettsia T4SS lacking only virB5 relative to the vir archetype. Phylogeny estimation suggests vertical inheritance of all components, despite gene rearrangements into an archipelago of five islets. Similarities of Rickettsia VirB7/VirB9 to ComB7/ComB9 proteins of epsilon-proteobacteria, as well as phylogenetic affinities to the Legionella lvh T4SS, imply the Rickettsiales ancestor acquired a vir-like locus from distantly related bacteria, perhaps while residing in a protozoan host. Modern modifications of these systems likely reflect diversification with various eukaryotic host cells.We present the rvh (Rickettsiales vir homolog) T4SS, an evolutionary conserved transporter with an unknown role in rickettsial biology. This work lays the foundation for future laboratory characterization of this system, and also identifies the Legionella lvh T4SS as a suitable genetic model
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