Search

Text mining has been used for various purposes, such as document classification and extraction of domain-specific information from text. In this paper we present a study in which text mining methodology and algorithms were properly employed for academic dishonesty (cheating) detection and evaluation on open-ended college exams, based on document classification techniques. Firstly, we propose two classification models for cheating detection by using a decision tree supervised algorithm. Then, both classifiers are compared against the result produced by a domain expert. The results point out that one of the classifiers achieved an excellent quality in detecting and evaluating cheating in exams, making possible its use in real school and college environments

Habitat loss and natural vegetation fragmentation are significant causes of global biodiversity decline, impacting plant and animal species negatively. This issue is worrisome in the private areas of Cerrado in Brazil, which is the second-largest biome, considered a hotspot for biodiversity conservation, and a provider of ecosystem services. Herein, we present a novel integrated approach to define priority areas for biodiversity conservation and environmental compensation in Cerrado, using multicriteria analysis. Our approach combines variables like deforestation projection, integral index of connectivity, threatened species occurrence, and environmental information of rural properties, ranking the importance of remaining native vegetation for biodiversity conservation and forest certificate issuance. Landscape metrics were used to observe and predict land use and land cover changes from 1988 to 2038. We found a loss of native vegetation in the Cerrado superior to 20% between 1988 and 2018, associated with increased of its fragmentation and its connectivity loss, especially after 2008. Natural cover was replaced mostly by pasture and more recently by agriculture. Moreover, we determined that is expected a loss of native vegetation of around 55% by 2038 in the study area. The proposed approach can predict the consequences of future changes in the landscape of the private areas in the Cerrado biome. It should be replicated in other ecosystems, supporting the decision-making process for biodiversity protection. [ABSTRACT FROM AUTHOR]

The impact of agricultural land-use on soil microbial community composition and enzyme activity has not been extensively investigated in Ultisols. We investigated soil health parameters by analyzing phospholipid fatty acids (PLFAs), extracellular enzyme activity, C and N stocks, and soil structure. Four land uses were established in a tropical climate region of Brazil: native Cerrado (savanna), monoculture pasture [Urochloa brizantha (Hochst. Ex A. Rich.) R. Webster 'Marandu'], an integrated crop-livestock system (ICLS), and maize (Zea mays)-fallow in a no-tillage system. Soil microbial biomass was 40% higher in the native Cerrado than in the monoculture pasture, ICLS, and no-tillage maize. Soil organic carbon was positively correlated with microbial community composition (MB; gram–; AC; AMF; Fungi; F: B ratio) and enzyme activity (bG, AP, NAG). Large macroaggregates were positively correlated with bG, AP, and AMF. In summary, the native Cerrado had a higher level of carbon at the soil surface and greater soil structure with increased microbial biomass, gram+ bacteria, AMF, fungi, and F:B ratio in a tropical region of Brazil. However, bG and AP enzyme activities were lower in the ICLS and no-till maize at the soil surface (0–5 cm) compared to the native Cerrado. The conversion of native Cerrado to agricultural systems shifted the soil microbial community composition, enzyme activity, C and N, and soil structure of this sandy soil of the Brazilian Cerrado. [ABSTRACT FROM AUTHOR]

Soil microbial community and enzyme activity regulate carbon and nutrient cycling in soils. No‐till has elevated levels of carbon at the soil surface compared to intensively tilled soils. The introduction of crop diversification in agricultural systems increases soil carbon protection and aggregate stability. Thus, the association of no‐till with crop diversification may change the soil microbial distribution and enhance activity in comparison with tilled soils with no crop diversification. We tested this hypothesis assessing the soil microbial community and enzyme activity in a long‐term (32 yr) experiment with contrasting soil management (no‐tillage, (NT) and conventional tillage (CT)) and cropping systems in southern Brazil. Long‐term NT increased microbial biomass at 0–5 cm. In contrast, soil microbial biomass was higher in deeper soil layers (10–30 cm) of CT. No‐tillage and crop diversification increased the activity of β‐glucosidase, acid phosphatase and N‐acetyl‐glucosaminidase. The benefits of an intensified/diversified crop rotation were offset by soil tillage. The higher abundance of PLFA groups at 0–5 cm and 10–30 cm of respective NT and CT soils were correlated with increased C and nutrient levels (N, Ca2+, Mg2+) and decreased Al3+. Highlights: Crop diversification increased the soil microbial biomass and individual PLFA groups.No‐till without crop diversification did not change microbial biomass.No‐till with crop diversification increased enzyme activity.Subsoil fertility restricted microbial responses in a no‐till Oxisol. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciência & Saúde Coletiva is the property of Associacao Brasileira de Pos-Graduacao em Saude Coletiva and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents a study which examined propagation of vancomycin A-containing Enterococcus faecium and Enterococcus faecalis strains in hospital patients with multilocus sequence typing (MLST) lineages. Several testst are performed including water sample collection and analysis, microdilution technique and polymerase chain reaction (PCR). The vancomycin-resistance in both strains are measured.

We report changes in the molecular epidemiology of vanA -containing Enterococcus during the intra and interhospital spread of high-risk clones, in Southeastern Brazil. While VRE faecalis predominated during 1998 to 2006, a reversal has been observed in the last years, where VRE faecium belonging to ST114, ST203, ST412, ST478 and ST858 have become endemic. [ABSTRACT FROM AUTHOR]