83 research outputs found
Challenges and opportunities for a South America Waterway System
South America has been developed from its coast to its hinterlands since the beginning of its Western colonization. However, to this point, no significant effort has been made to integrate its interior. Waterways transportation can be considered the most sustainable inland mode of transportation due to its low CO2 emissions per ton of cargo transport. With this in mind, this paper investigates the history, challenges and opportunities of the past proposals for the construction of the South America Waterway System (SAWS) connecting the La Plata, Amazon, and Orinoco river basins. It focuses on particular challenges of the proposed waterway. (i) a comparison between the deforestation surrounding existing road and waterway infrastructure in the Amazon, (ii) the large water level variation in the Amazon basin, (iii) and the alternatives for storing water to reduce the impacts of floods and droughts in the proposed waterway. We conclude that deforestation surrounding existing waterways is practically zero and that groundwater storage has an important role in storing water for the basin and reservoirs, a limited one. The SAWS can significantly foster South American integration, encourage sustainable extraction of natural resources in the region and help the conservation of the Amazon forest
IFNL4 ss469415590 polymorphism is associated with unfavourable clinical and immunological status in HIV-infected individuals
AbstractThe IFNL4 ss469415590 polymorphism, in high linkage disequilibrium with the IL28B rs12979860 variant, has been associated with hepatitis C virus clearance. We evaluated whether ss469415590 is associated with clinical and immunovirological parameters in human immunodeficiency virus-infected subjects. We found an independent association of the IFNL4 ss469415590 polymorphism with higher prevalence of AIDS-defining illnesses and lower CD4 T cell numbers. These results suggest the existence of common host defence mechanisms against different viral infections
Determination of metals in medicinal plants highly consumed in Brazil
In this work, samples of the medicinal plants: Boldo (Peumus boldus), Castanha da Índia (Aesculus hippocastanum), Chá Verde (Camelia sinensis), Erva Cidreira (Melissa officinalis), Espinheira Santa (Maytenus ilicifolia), Guaraná (Paullinia cupana), Maracujá (Passiflora sp.), Mulungu (Erythrina velutina), Sene (Cassia angustifolia) and Valeriana (Valeriana officinalis) were evaluated BY using the Neutron Activation Analysis technique (NAA- k0) in order to determine the levels of metals and other chemical contaminants. The results showed the presence of non essential elements to the human body. The diversity of chemical impurities found even at low concentration levels, considering the potential for chronic toxicity of these elements, reinforces the need to improve the implementation of good practices by growers and traders, and the hypothesis of lack of quality control in plant products
Evaluation of PCR and multiplex PCR in relation to nested PCR for diagnosing Theileria equi
Conventional PCR (PCRTeq) for diagnosing Theileria equi and multiplex PCR (M/PCRTeq-Bc) for diagnosing T. equi and Babesia caballi were comparatively evaluated with nested PCR (N/PCR-Teq) for diagnosing equine piroplasmosis. In DNA sensitivity determinations, in multiple dilutions of equine blood that had tested positive for T. equi, PCR-Teq and N/PCR-Teq detected hemoparasite DNA in the larger dilutions (1:128), but did not differ significantly from the M/PCRTeq-Bc (1:64). In analyses on equine serum tested by ELISA, there was high agreement between this serological test and PCR-Teq (k = 0.780) and moderate agreement with N/PCR-Teq (k = 0.562) and M/PCRTeq-Bc (k = 0.488). PCR-Teq found a higher frequency of T. equi both in extensively and intensively reared horses, but this was not significant in relation to N/PCR-Teq (P>0.05), and both PCRs indicated that there was an endemic situation regarding T. equi in the population of horses of this sample. PCR-Teq was only significantly different from M/PCR-Teq-Bc (P<0.05). PCR-Teq presented high sensitivity and specificity, comparable to N/PCR-Teq, but with the advantage of higher speed in obtaining results and lower costs and risks of laboratory contamination. This accredits PCR-Teq for epidemiological studies and for determinations on affected horses
Consumo de matéria seca e desempenho de novilhas das raças Girolando e Guzerá sob suplementação na caatinga, na época chuvosa, em Pernambuco, Brasil
Com os objetivos de estimar o consumo de matéria seca e avaliar a variação do peso vivo de novilhas, conduziu-se um experimento no período entre março e julho de 2003, com quatro estratégias de suplementação: sem suplementação (controle); torta de algodão (1 kg); palma-forrageira (10 kg); e de palma (5,0 kg) + torta de algodão (0,5 kg). O fornecimento de suplemento não influenciou o consumo de matéria seca (MS) do pasto nativo, no entanto afetou o consumo de MS total. O consumo de matéria seca total diferiu entre as raças, com valores de 5,44 e 6,75 kg/dia, respectivamente, para as raças Guzerá e Girolando. Nos animais sob suplementação com torta de algodão, o consumo de MS total foi superior ao do grupo controle (sem suplementação), porém semelhante ao daqueles sob suplementação com palma-forrageira e com torta de algodão + palma-forrageira. O ganho de peso vivo médio diário (de 517 e 434 g/animal, respectivamente, para os grupos Girolando e Guzerá) não diferiu entre as raças nem foi influenciado pela interação raça õ suplementação. Entre as estratégias de suplementação, no entanto, os valores tiveram diferença significativa e foram de 412, 620, 371 e 498 g/animal/dia, respectivamente, para os grupos controle e sob suplementação com torta de algodão; palma-forrageira; torta de algodão + palma-forrageira. No semiárido de Pernambuco, a suplementação com 1 kg de torta de algodão na época chuvosa do ano melhora o ganho de peso médio diário, independentemente da raça do animal
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