Universidade Federal de Mato Grosso

About: Universidade Federal de Mato Grosso is a education organization based out in Cuiabá, Brazil. It is known for research contribution in the topics: Population & Species richness. The organization has 7748 authors who have published 10181 publications receiving 89994 citations.

Fatores ambientais sobre a germinação de Emilia sonchifolia

Abstract: The knowledge of basic aspects of the biology of weeds can contribute significantly to the development of strategies for their handling. Emilia sonchifolia is a weed spread throughout the Brazilian territory; it presents moderate aggressiveness being found in agricultural and urban areas. This work aimed to evaluate germination of E. sonchifolia seeds in temperature conditions and brightness, stress osmotic, saline and pH of solution. Four experiments were accomplished: a) combination of four temperatures (20 oC, 25 oC, 30 oC and 35 oC) in two conditions of brightness (light absence and presence); b) seven levels of osmotic stress provided for PEG6000 (0; -0.1; -0.2; -0.4; -0.6; -0.8 and -1.0 MPa); c) six levels of saline stress provided for NaCl (0.0; -0.2; -0.4; -0.6; -0.8 and -1.0 MPa) and d) six pH levels (3.0; 5.0; 6.0; 7.0; 9.0 and 11.0) in buffer solutions. The germination of E. sonchifolia seeds was maximized in the presence of light , at constant temperatures of 25 and 30 oC. There was reduction of germination in conditions with osmotic stress starting from -0.1 MPa and of -0.2 MPa for saline stress. E. sonchifolia is sensive to pH variation, with greater germination of seeds occurring only at pH 6.0.

Integrated production systems: An alternative to soil chemical quality restoration in the Cerrado-Amazon ecotone

Abstract: Soil organic carbon (SOC) is the main terrestrial carbon reservoir. The spatial distribution of SOC is mainly regulated by environmental factors and anthropogenic activity. Historically, land-use change has been responsible for much of the world’s greenhouse gas emissions. However, carbon storage can be improved through agricultural management, either by increasing carbon inputs through higher crop yields or by delaying the release of carbon into the atmosphere. Therefore, it is essential to correctly choose which cover crops to use and how long these crops will remain in the crop rotation system. In order to clarify these issues, the objective of this work was to evaluate the chemical quality and changes in soil carbon stock between no-tillage and soybean/corn crop succession systems and integrated crop-livestock systems. The study was carried out in Querencia (MT), Brazil, located in the Cerrado/Amazon ecotone. The integrated systems were studied between 2007 and 2014. These systems followed annual crop rotation and forage rotation, and were laid out as a consortium or were isolated, with the aim of producing grain and meat. In order to determine soil chemical properties, 170 sampling plots were randomized among the treatments. The highest carbon values were observed in the integrated crop-livestock systems (ICL), probably due to higher inputs of organic residues. Crop rotation with plants of different families allowed better land use and soil exploration. However, integrated production systems comprising longer pasture periods, no-tillage, and soybean/corn crop succession decreased soil carbon. When comparing carbon stocks from 2010 to 2014, only integrated production systems ICL2 and ICL3 were able to increase carbon stocks. Our results highlight the importance of length of growing and correct choice of cover crops in maintaining SOC stocks, and thus provide insights to improve SOC stocks in agricultural land in Brazil's main producing region.

Thermodynamic properties of drying process and water absorption of rice grains

Abstract: This study aimed to obtain the drying and water absorption curves of husk rice grain (Oryza sativa L.), cv. Urucuia, as well as the thermodynamic properties. Five temperatures (35°C, 45°C, 55°C, 65°C and 75°C) were used. Two terms, logarithmic, modified Midilli, Page and Verma models were used to model the drying process, and the Peleg model was used to model the soaking process. The modified Midilli and Peleg models satisfactorily accounted for the processes of drying and absorption of water, respectively. The activation energy for the drying and soaking was 51.03 and 37.06 kJ mol−1, respectively. The enthalpy and entropy decreased with increasing temperature, regardless of the process. Their values ranged between −6.60 and 48.47 kJ mol−1 and between −0.1084 and −0.2464 kJ mol−1 K−1 for enthalpy and entropy, respectively. The Gibbs free energy increased with increasing temperature, with values between 69.36 and 86.22 kJ mol−1.

Personality, dangerous driving, and involvement in accidents: Testing a contextual mediated model

Abstract: The present study tested the role of various personality traits in explaining dangerous driving and involvement in accidents, using a contextual mediated model (N = 311). We initially found direct effects of personality traits on dangerous driving indicators (Big-5, Dark Triad, sensation seeking, aggression, and impulsivity). Subsequently, personality variables with predictive power were tested in the mediation model. Indirect effects of anger, psychopathy and sensation seeking on the history of involvement in traffic accidents were found, which was predicted directly by risky driving. The results are discussed based on the characteristics of each trait. Overall, our research replicates and extends previous findings and highlights the importance of psychological evaluations (e.g., personality test) when prospective drivers are applying for a driver license.