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.

Ecologia global contra diversidade cultural? Conservação da natureza e povos indígenas no Brasil: O Monte Roraima entre Parque Nacional e terra indígena Raposa-Serra do Sol

Abstract: Nature conservation policies in different countries are increasingly linked to global ecological decision making. Examples of such linkages abound, and range from priorities and policy objectives defined in international forums and institutions to the action of global environmentally concerned NGOs, to global environmental and sustainable development funds and programmes, and new economic opportunities represented by emerging markets for global ecological services and environmental commodities. These policies often clash with the needs and rights of different populations, since the implementation of man-excluding protected areas is given priority over other models of biodiversity conservation and sustainable use. Brazil is no exception to this rule: today, nature conservation policies are entering in direct conflict with policies preserving indigenous people’s rights to cultural difference. This is happening at different levels, and in several different local contexts, from the Atlantic to the Amazon and the Guyana Shield regions. Global policy priorities and funding can contribute to explain these conflicts, as the global ecological link contributes to redefine national and local political relations. The case of Mount Roraima National Park, overlapping with the Raposa-Serra do Sol Indigenous Land, illustrates how conservation policies based on man exclusion, such as National Parks, conceived and implemented in a top-down fashion, stimulate pre-existing political and land rights conflicts. Approached through a different angle, this case also indicates a possible way to viable solutions. By talking, canoeing and walking with the Ingariko Indians across the Serra do Sol, their own cultural ecological perspective can be perceived as a fundamental element in natural resource conservation. Adopting the indians' cultural perspective to elucidate their effective rules for the use and management of natural resources can be the starting point to develop and implement ecologically effective and socially beneficial management plans. Re-directing global willingness to pay for biodiversity conservation to indigenous peoples would contribute to make that happen.

Dano de frio em limas-ácidas Tahiti, colhidas em diferentes épocas e submetidas a tratamentos térmicos e bioquímicos

Abstract: O estudo objetivou o estabelecimento de um metodo efetivo e satisfatorio do controle do dano de frio em limas-acidas. Os frutos colhidos no municipio de Boa Vista-RR, 140 e 150 dias apos a floracao, apresentaram valores medios de 7,9 e 8,2 oBrix; 6,3 e 6,0 mL de acido citrico.100mL de polpa-1 e pH de 2,8 e 3,0, respectivamente, nas duas colheitas. Apos cada colheita, os frutos foram levados ao laboratorio de Fitotecnia/UFRR, onde foram selecionados, limpos e submetidos aos tratamentos: T1 - controle; T2, T3 e T4 - condicionamento a 35oC, por 6, 12 e 24 horas, respectivamente; T5 - aquecimento intermitente a 20oC, por 8 horas, apos 5 e 10 dias a 1oC; T6 - aquecimento intermitente a 20oC, por 8 horas, apos 10 e 20 dias a 1oC; T7 - ethephon a 1.500 mg.L-1; T8 - ethephon a 3.000 mg.L-1. Os tratamentos T9 ao T16, diferenciaram-se dos tratamentos T1 a T8, apenas, na data da colheita (10 dias apos a primeira). O experimento foi avaliado a cada 15 dias, durante 75 dias, a 1 ± 0,5 oC e 92 ± 5 % de UR, quanto ao dano de frio, aspecto visual, perda de massa fresca, solidos soluveis (SS), acidez titulavel (AT), SS/AT (ratio - RT), clorofila total e acido ascorbico. O atraso na colheita nao proporcionou efeito significativo algum. Todos os tratamentos, a excecao do controle e do aquecimento intermitente aos 10 e 20 dias, foram eficientes no controle do dano de frio. No entanto, o tratamento quimico e o condicionamento termico aceleraram precocemente o metabolismo dos frutos, principalmente no que concerne a perda de massa fresca e ao aspecto visual. O maior teor de clorofila total e de acido ascorbico, bem como o melhor aspecto visual, a nao-incidencia de podridoes e a menor perda de massa fresca foram detectadas nos frutos submetidos ao aquecimento intermitente aos 5 e 10 dias. Os SS, AT e RT estavam dentro dos padroes de qualidade e nao variaram estatisticamente entre os tratamentos.

Does Oil Rich in Alpha-Linolenic Fatty Acid Cause the Same Immune Modulation as Fish Oil in Walker 256 Tumor-Bearing Rats?

Abstract: Objective: Polyunsaturated fatty acids n-3 (PUFA n-3) have shown effects in reducing tumor growth, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) abundantly present in fish oil (FO). When these fatty acids are provided in the diet, they alter the functions of the cells, particularly in tumor and immune cells. However, the effects of α-linolenic fatty acid (ALA), which is the precursor of EPA and DHA, are controversial. Thus, our objective was to test the effect of this parental fatty acid. Methods: Non-tumor-bearing and tumor-bearing Wistar rats (70 days) were supplemented with 1 g/kg body weight of FO or Oro Inca® (OI) oil (rich in ALA). Immune cells function, proliferation, cytokine production, and subpopulation profile were evaluated. Results: We have shown that innate immune cells enhanced phagocytosis capacity, and increased processing and elimination of antigens. Moreover, there was a decrease in production of pro-inflammatory cytokines (tumor necrosis factor-alpha ...

Arbuscular mycorrhizal fungi (Glomeromycota) communities in tropical savannas of Roraima, Brazil

Abstract: Savanna vegetation in the northern region of Brazil is jeopardized by several anthropogenic activities including cattle ranching and extensive agriculture, and soil biota of these ecosystems is virtually unknown. The soils in savannas are poor in nutrients, very acidic, and subject to drought, and under these conditions, arbuscular mycorrhizal fungi (AMF) are likely to play a key role on plant nutrition and improving soil structure. In this study, we surveyed AMF communities in five savanna locations in Roraima state, Northern Brazil. AMF species were identified using two approaches: field collected spores and trap cultures. Twenty-three AMF species were identified, including 21 species in field samples, 8 species in trap cultures, of which 15 and 2 were unique to field and trap culture samples, respectively. Gigaspora margarita, Dentiscutata heterogama, and Glomus sp1 were the most frequent species recovered from all locations. AMF communities were dominated by members of Gigasporaceae that accounted for 50 to 87% of the total species richness within each location. Spore numbers differed across locations and ranged from 5 to 25 spores 100 cm−3 soil. Redundancy analysis indicated that soil organic matter was the only selected predictor among soil parameters and correlated positively with occurrence of Glomus heterosporum. We conclude that savannas in Roraima harbor a high sporulating AMF species richness with communities dominated by members of Gigasporaceae and that organic carbon is an important edaphic factor influencing AMF community composition in this ecosystem.