Universidade Federal Rural do Rio de Janeiro

About: Universidade Federal Rural do Rio de Janeiro is a education organization based out in Seropédica, Brazil. It is known for research contribution in the topics: Population & Species richness. The organization has 6405 authors who have published 9852 publications receiving 105911 citations.

Reassessment of the potential economic impact of cattle parasites in Brazil

Abstract: The profitability of livestock activities can be diminished significantly by the effects of parasites. Economic losses caused by cattle parasites in Brazil were estimated on an annual basis, considering the total number of animals at risk and the potential detrimental effects of parasitism on cattle productivity. Estimates in U.S. dollars (USD) were based on reported yield losses among untreated animals and reflected some of the effects of parasitic diseases. Relevant parasites that affect cattle productivity in Brazil, and their economic impact in USD billions include: gastrointestinal nematodes - $7.11; cattle tick (Rhipicephalus (Boophilus) microplus) - $3.24; horn fly ( Haematobia irritans) - $2.56; cattle grub (Dermatobia hominis) - $0.38; New World screwworm fly ( Cochliomyia hominivorax) - $0.34; and stable fly (Stomoxys calcitrans) - $0.34. The combined annual economic loss due to internal and external parasites of cattle in Brazil considered here was estimated to be at least USD 13.96 billion. These findings are discussed in the context of methodologies and research that are required in order to improve the accuracy of these economic impact assessments. This information needs to be taken into consideration when developing sustainable policies for mitigating the impact of parasitism on the profitability of Brazilian cattle producers.

Change in carbon and nitrogen stocks in soil under 13 years of conventional or zero tillage in southern Brazil

Abstract: The objective of this study was to determine in a long-term experiment (13 years) the effect of three different crop rotations (R1: wheat (Triticum aestivum)–soybean (Glycine max), R2: wheat–soybean–vetch (Vicia villosa)–maize (Zea mays), and R3: wheat–soybean–oat (Avena sativa)–soybean–vetch–maize) under zero tillage (ZT) and conventional tillage (CT) on the stocks of soil organic matter (SOM) in a clayey Oxisol soil of Passo Fundo, Rio Grande do Sul. At the end of 13 years, soil samples were taken to a depth of 100 cm, and analysed for bulk density, chemical composition and 13 C natural abundance. Under a continuous sequence of wheat (winter) and soybean (summer) the stock of soil organic C to 100 cm depth under ZT (168 Mg ha −1 ) was not significantly different (LSD at P = 0.05 of 11 Mg ha −1 ) to that under CT (168 Mg ha −1 ). However, in the rotations with vetch planted as a winter green-manure crop (R2 and R3), soil C stocks were approximately 17 Mg ha −1 higher under ZT than under CT. Between 46 and 68% of this difference occurred at 30–85 cm depth. The 13 C abundance data indicated that under ZT the decomposition of the original native SOM was not affected by the different composition of crops in the different rotations, but under CT the rotations R2 and R3, which included vetch and maize, stimulated the decay of the original native SOM compared to the continuous wheat/soybean sequence (R1). It appears that the contribution of N2 fixation by the leguminous green manure (vetch) in the cropping system was the principal factor responsible for the observed C accumulation in the soil under ZT, and that most accumulated C was derived from crop roots. © 2003 Elsevier B.V. All rights reserved.

Payments for ecosystem services and the fatal attraction of win-win solutions

Abstract: In this commentary we critically discuss the suitability of payments for ecosystem services and the most important challenges they face. While such instruments can play a role in improving environmental governance, we argue that over-reliance on payments as win-win solutions might lead to ineffective outcomes, similar to earlier experience with integrated conservation and development projects. Our objective is to raise awareness, particularly among policy makers and practitioners, about the limitations of such instruments and to encourage a dialogue about the policy contexts in which they might be appropriate.

Use of essential oils in active food packaging: Recent advances and future trends

Abstract: Background Essential oils (EOs) extracted from plants have been the focus of numerous researches due to their potential in the food and pharmaceutical industries and aromatherapy. Scope and approach The effectiveness of EO may be observed in antimicrobial and antioxidant tests. Volatile compounds are present in EOs and are responsible by their biological activities, namely antimicrobial and antioxidant capacity. Several manuscripts and patents have emerged with applications of EOs and their constituents, and their incorporation into food packaging. These packages with EOs have shown efficiency against microorganisms and oxidants in vitro, in tests with food and/or food simulants evaluation tests. In line with this, chromatographic techniques can be used to identify the main volatile compounds present in EOs or to determine the compounds that migrated from packaging to food or food simulants. This review provides a concise and critical insight in the use of EOs with emphasis in food applications. The innovative food packaging applications are highlighted and future trends are discussed. Key findings and conclusions In general, EOs extend food stability during storage, inhibiting the growth of spoilage or pathogenic microorganisms and protecting against oxidation. Moreover, in spite of the potential of EOs, more studies should evaluate their safety and possible side effects before considering their use for food purposes.

Impact of environment and social gradient on Leptospira infection in urban slums.

Abstract: Background Leptospirosis has become an urban health problem as slum settlements have expanded worldwide. Efforts to identify interventions for urban leptospirosis have been hampered by the lack of population-based information on Leptospira transmission determinants. The aim of the study was to estimate the prevalence of Leptospira infection and identify risk factors for infection in the urban slum setting.