Universidade Federal de Minas Gerais

About: Universidade Federal de Minas Gerais is a education organization based out in Belo Horizonte, Minas Gerais, Brazil. It is known for research contribution in the topics: Population & Context (language use). The organization has 41631 authors who have published 75688 publications receiving 1249905 citations.

The rotten apples of Brazil's agribusiness

Abstract: Brazil's inability to tackle illegal deforestation puts the future of its agribusiness at risk In the increasingly polarized international political arena, it has become difficult to find common ground to solve Brazil's ongoing environmental crisis, which has global as well as local implications. International buyers of Brazil's agricultural commodities have raised concerns about products that are contaminated by deforestation (i.e., deforestation occurred during the process of producing the product) (text S12). European Union (EU) criticism of the Brazilian government bolsters demands to boycott Brazilian products and to withhold ratification of the trade agreement reached in 2019 between the EU and Mercosur, the South American trade bloc. Among the concerns is that increasing greenhouse gas (GHG) emissions from deforestation and forest fires in Brazil could cancel out EU climate change mitigation efforts. The Brazilian government and agribusiness contend that national laws ensure high conservation standards, and hence trading bans should not include legally authorized deforestation (1). Here, we address the interlinkage between illegal deforestation in the Amazon and Cerrado—the largest Brazilian biomes with the highest rates of deforestation—and EU imports of Brazil's soy and beef, the country's major agricultural commodities (table S9). Although most of Brazil's agricultural output is deforestation-free, we find that 2% of properties in the Amazon and Cerrado are responsible for 62% of all potentially illegal deforestation and that roughly 20% of soy exports and at least 17% of beef exports from both biomes to the EU may be contaminated with illegal deforestation. Raising awareness is important to press Brazil to conserve its environmental assets and to promote international political will for cutting telecoupled GHG emissions. This could be achieved, for example, through the environmental safeguards of the Mercosur-EU trade agreement, which require EU imports to comply with the export country's legislation.

The Central Siberian Origin for Native American Y Chromosomes

Abstract: Y chromosomal DNA polymorphisms were used to investigate Pleistocene male migrations to the American continent. In a worldwide sample of 306 men, we obtained 32 haplotypes constructed with the variation found in 30 distinct polymorphic sites. The major Y haplotype present in most Native Americans was traced back to recent ancestors common with Siberians, namely, the Kets and Altaians from the Yenissey River Basin and Altai Mountains, respectively. Going further back, the next common ancestor gave rise also to Caucasoid Y chromosomes, probably from the central Eurasian region. This study, therefore, suggests a predominantly central Siberian origin for Native American paternal lineages for those who could have migrated to the Americas during the Upper Pleistocene.

Operon mer: bacterial resistance to mercury and potential for bioremediation of contaminated environments.

Abstract: Mercury is present in the environment as a result of natural processes and from anthropogenic sources. The amount of mercury mobilized and released into the biosphere has increased since the beginning of the industrial age. Generally, mercury accumulates upwards through aquatic food chains, so that organisms at higher trophic levels have higher mercury concentrations. Some bacteria are able to resist heavy metal contamination through chemical transformation by reduction, oxidation, methylation and demethylation. One of the best understood biological systems for detoxifying organometallic or inorganic compounds involves the mer operon. The mer determinants, RTPCDAB, in these bacteria are often located in plasmids or transposons and can also be found in chromosomes. There are two classes of mercury resistance: narrow-spectrum specifies resistance to inorganic mercury, while broad-spectrum includes resistance to organomercurials, encoded by the gene merB. The regulatory gene merR is transcribed from a promoter that is divergently oriented from the promoter for the other mer genes. MerR regulates the expression of the structural genes of the operon in both a positive and a negative fashion. Resistance is due to Hg2+ being taken up into the cell and delivered to the NADPH-dependent flavoenzyme mercuric reductase, which catalyzes the two-electron reduction of Hg2+ to volatile, low-toxicity Hg0. The potential for bioremediation applications of the microbial mer operon has been long recognized; consequently, Escherichia coli and other wild and genetically engineered organisms for the bioremediation of Hg2+-contaminated environments have been assayed by several laboratories.

Deep into the mud: ecological and socio-economic impacts of the dam breach in Mariana, Brazil

Abstract: We review the ecological and socio-economic impacts of the catastrophic dam failure in Mariana, Brazil. Tailing management practices by Samarco mining company ultimately caused a dam breach that abruptly discharged between 55 and 62 million m3 of tailings into the Doce River watershed. On November 5th, 2015, a tsunami of slurry engulfed the small district of Bento Rodrigues, loading the Doce River and its estuary with toxic tailings along a 663.2 km trajectory, extending impacts to the Atlantic coast. Acute ecological impacts will adversely affect livelihoods of more than 1 million people in 41 riparian municipalities by reducing local access to fisheries resources, clean water, crop production sites, hydroelectric power generation and raw materials. The threats to riverine human communities are particularly critical for the disadvantaged populations from remote areas that rely on subsistence agriculture and fisheries, and are uniquely vulnerable to long-term heavy metal exposure. At the landscape scale, we predict multiple negative impacts, ranging from alterations of the genetic diversity of fish populations to long-term vegetation loss and poor regeneration in contaminated areas. Consequently, compromised soil stability and runoff control will increase the risk of further geomorphologic disturbance, including landslides, bank failure and mass movements. We propose spatially explicit long-term monitoring frameworks and priority mitigation measures to cope with acute and chronic risks. We posit that, from a national perspective, disastrous impacts like that of Doce River may become more frequent, given the recent regulatory changes that undermine both institutional governance structures and enforcement of environmental regulation.

Composition of green and roasted coffees of different cup qualities

Abstract: One of the most important criteria used for assessing coffee quality is based on sensory analysis and is referred to as cup quality. The presence of defective coffee beans is quite relevant to coffee quality. However, the majority of data on coffee properties are restricted to supposedly good quality beans. Therefore, the present study is aimed at an evaluation of physical and chemical attributes of coffees of different qualities, both green and roasted. Arabica coffee samples, previously classified by cup as soft (higher quality), hard, rioysh and rio (lower quality), were roasted at 200 °C for 1 h. Regarding attributes of green coffee beans, both bean density and volume were higher for the soft sample compared to the rio one. The soft sample also presented higher protein levels, due to its higher caffeine contents. The rio sample presented lower lipid contents, probably associated to the presence of defective beans. Acidity increased and pH levels decreased as cup quality decreased, probably due to the effect of defective beans that undergone fermentation (sour beans). After roasting, the rio sample presented higher density and trigonelline levels, indicating that it did not roast to the same degree as the other samples.