Federal University of Roraima

About: Federal University of Roraima is a based out in . It is known for research contribution in the topics: Population & Thermogravimetry. The organization has 981 authors who have published 1218 publications receiving 7849 citations. The organization is also known as: Federal University of Roraima.

Sclerotium delphinii causing concentric leaf spots in Piper nigrum in Brazil

Abstract: Sclerotium delphinii is a common pathogen that causes wilting in a number of plants. In recent years, the genus Sclerotium has been reported as one of those responsible for leaf spots in Piper nigrum in the Amazonian humid tropical regions. In 2017–2018, several black pepper plants presented symptoms of concentric leaf spots. Five isolates were obtained in this study for morphological and phylogenetic characterizations and pathogenicity test. Initially, the gene regions (ITS and LSU) were amplified and sequenced. Phylogenetic analysis confirmed the grouping of the five isolates with the S. delphinii reference isolate (CBS 672.71). The isolates produced sclerotia in all culture media, but some of them altered their capacity to produce sclerotia. The inoculated isolates induced irregular necrotic lesions in the pathogenicity assay using detached leaves. The symptomatic leaves were re-isolated and the fungus culture obtained. No fungus growth was observed in the leaves used as control. This study is the first record of S. delphinii causing leaf spots on P. nigrum in Brazil.

Hydro-edaphic conditions defining richness and species composition in savanna areas of the northern Brazilian Amazonia.

Abstract: BACKGROUND Studies on plant communities in the Amazon have reported that different hydro-edaphic conditions can affect the richness and the species composition of different ecosystems. However, this aspect is poorly known in the different savanna habitats. Understanding how populations and plant communities are distributed in these open vegetation areas is important to improve the knowledge about which environmental variables influence the occurrence and diversity of plants in this type of regional ecosystem. Thus, this study investigated the richness and composition of plant species in two savanna areas of the northern Brazilian Amazonia, using the coverage (%) of the different life forms observed under different hydro-edaphic conditions as a structural reference. NEW INFORMATION We report 128 plant species classified in 34 botanical families distributed in three savanna habitats with different levels of hydro-edaphic restrictions. In this study, the habitats are conceptually presented and they integrate environmental information (edaphic factors and drainage type), which determines differences between floristic composition, species richness and coverage (%) of plant life forms.

Are seedlings diagnostic in Neotropical Entada (Leguminosae)? Seedling morphology supports the reinstatement of Entada polyphylla

Abstract: Entada (Leguminosae) is a pantropical genus encompassing four Neotropical species, E. gigas ( E. sect . Entada ), E. polyphylla, E. polystachya and E. simplicata ( E . sect. Entadopsis ). However, the taxonomic status of E. polyphylla is still disputed, being treated as a separate species or a variety of E. polystachya. This article aims to take a comprehensive view of seedlings of Neotropical Entada, addressing the question of whether seedling morphology provide diagnostic characters that support the recognition of E. polyphylla at the species level. Seedlings of E. polyphylla were described and illustrated, whilst seedling data for the remaining Neotropical species were based on the literature. Entada polyphylla has an exclusive set of seedling characters within E. sect . Entadopsis, including cryptocotylar, hypogeal, reserve seedlings, long cotyledonary petioles, short cotyledon lobes, cataphylls and alternate, bipinnate eophylls. Therefore, seedling morphology supports the recognition of E. polyphylla as a distinct species and its reinstatement is here proposed. In addition, each of the four New World species of Entada can be diagnosed by their seedlings, and an identification key is also provided.

A geometria de poder do conflito territorial entre fazendeiros e Guaranis-Kaiowás na fronteira do Brasil com o Paraguai (Geometry of power of conflict between farmers and territorial Guarani-Kaiowas on the border of Brazil with Paraguay)

Abstract: Tomando por base o conflito territorial entre fazendeiros e Guaranis-Kaiowas na fronteira do Brasil com o Paraguai, analisamos a geometria de poder que envolve o processo de demarcacao das terras indigenas no estado do Mato Grosso do Sul. Partindo da dinâmica de desterritorializacao vinculada a expansao da “modernizacao da agricultura” pelas monoculturas de soja, pecuaria e mais recentemente da cana-de-acucar, analisamos a luta de reterritorializacao dos povos indigenas pelo movimento de retomada de territorios tradicionais, os tekohas, em “acampamentos contingentes” articulados em redes de multiplas frentes de luta e escalas espaciais. A complexa geometria de poder dessa multiplicidade de sujeitos e produzida pela articulacao dos povos Guarani-Kaiowa em redes, em escalas de acao, partindo da local ate a internacional. Esse movimento promove, por parte dos fazendeiros, uma reacao de oposicao, construida por meio de aliancas e coalizacoes de classe, o que mobiliza contra-ataques para conter as territorialidades alternativas e de resistencia. Palavras-chave: fronteira, geometria de poder, demarcacao de terras indigenas, territorialidade Guarani-Kaiowa, Mato Grosso do Sul. ABSTRACT Based on the territorial conflict between farmers and Guarani-Kaiowas on the border of Brazil and Paraguay, we analyze the geometry of power that involves the process of demarcation of indigenous land in Mato Grosso do Sul. Leaving the dynamics of deterritorialization linked to expansion “modernization of agriculture”, monoculture soybean, livestock and more recently with cane sugar, we analyze the struggle of the indigenous peoples of repossession by the movement of resumption of traditional territories, tekohas in “contingent camps” articulated in networks multiple fronts of struggle and spatial scales. The complex geometry of power this multiplicity of subjects is produced by the articulation of the Guarani-Kaiowa people in networks, scales of action, starting from the local to the international. This movement promotes, by farmers, a reaction of opposition, built through alliances and coalitions class, which mobilizes counterattacks to contain alternatives and resistance territoriality. Keywords: border, power geometry, demarcation of indigenous lands, territoriality Guarani-Kaiowa, Mato Grosso do Sul. RESUMEN Con base en el conflicto territorial entre los agricultores y los Guarani-Kaiowas en la frontera de Brasil y Paraguay, se analiza la geometria del poder que implica el proceso de demarcacion de las tierras indigenas en Mato Grosso do Sul Dejando la dinamica de desterritorializacion vinculados a la expansion “modernizacion de la agricultura”, monocultivo de soja, la ganaderia y, mas recientemente, con azucar de cana, se analiza la lucha de los pueblos indigenas de la toma de posesion por el movimiento de la reanudacion de los territorios tradicionales, tekohas en “campos de contingentes” articulados en redes multiples frentes de lucha y de escalas espaciales . La compleja geometria del poder esta multiplicidad de sujetos se produce por la articulacion del pueblo Guarani-Kaiowa en redes, escalas de accion, a partir de lo local a lo internacional. Este movimiento promueve, por los agricultores, una reaccion de la oposicion, construido a traves de alianzas y coaliciones de clase, lo que moviliza a los contraataques para contener alternativas y territorialidad resistencia. Palabras clave: frontera, geometria poder, de demarcacion de las tierras indigenas, la territorialidad Guarani-Kaiowa, Mato Grosso do Sul. DOI: 10.5654/actageo2014.0004.0011

Corpos que bebem, dançam e trabalham juntos: entre os ritmos da festa e do trabalho coletivo nos Andes peruanos

Abstract: Em Andamarca, uma comunidad camponesa dos Andes peruanos, as festas e o trabalho coletivo consistem em momentos de grande importância, propicios para compartilhar comidas, bebidas e esforcos. O trabalho coletivo e empregado na construcao de casas de adobe, limpeza e construcao de canais de irrigacao, caminhos e estradas. Para os andamarquinos, a realizacao de atividades em equipes cria uma dinâmica capaz de proporcionar uma especie de competicao positiva, alem da manutencao e geracao de vinculos enquanto todos estao determinados a alcancar um objetivo comum. A divisao em grupos gera animo , isto e, a forca e a disposicao necessarias para realizar atividades consideradas duras e pesadas. Para que tal forca nao se acabe, durante o trabalho e feita uma distribuicao de substâncias que tambem produzem animo como bebidas alcoolicas e folhas de coca. O mesmo sucede nas festas, momentos em que a distribuicao e o consumo de bebidas alcoolicas sao fundamentais para fazer os participantes dancar, para gerar alegria e vontade de gozar, enfim, para criar uma determinada atmosfera ou ambiente caracteristico dos momentos de celebracao. Com base numa pesquisa etnografica, este texto propoe uma breve comparacao entre as festas e o trabalho coletivo, mostrando aproximacoes e diferencas entre esses dois movimentos, tendo em vista que o compartilhamento de esforcos e de substâncias sao meios fundamentais para alcancar a constituicao de coletivos em ambos os momentos. Ademais, os dois movimentos implicam transformacoes de ordem corporal e subjetiva a ponto de moldarem nao so o corpo mas tambem a pessoa andamarquina.