Universidade Estadual de Londrina

About: Universidade Estadual de Londrina is a education organization based out in Londrina, Brazil. It is known for research contribution in the topics: Population & Toxoplasma gondii. The organization has 13052 authors who have published 19291 publications receiving 212123 citations.

Photoaging and chronological aging profile: Understanding oxidation of the skin.

Abstract: The impact of chronological aging and photoaging on the skin is particularly concerning, especially when oxidative stress is involved. This article provides evidence of quantitative and qualitative differences in the oxidative stress generated by chronological aging and photoaging of the skin in HRS/J hairless mice. Analysis of the results revealed an increase in lipid peroxides as the skin gets older and in photoaged skin (10.086 ± 0.70 η MDA/mg and 14.303 ± 1.81 η MDA/mg protein, respectively), although protein oxidation was only verified in chronological aged skin (15.449 ± 0.99 η protein/mg protein). The difference between both skin types is the decay in the capacity of lipid membrane turnover revealed by the dislocation of older skin to the left in the chemiluminescence curve. Imbalance between antioxidant and oxidation processes was verified by the decrease in total antioxidant capacity of chronological and photoaged skins. Although superoxide dismutase remained unchanged, catalase increased in the 18 and 48-week-old skin groups and decreased in irradiated mice, demonstrating that neither enzyme is a good parameter to determine oxidative stress. The differences observed between chronological and photoaging skin represent a potential new approach to understanding the phenomenon of skin aging and a new target for therapeutic intervention.

The costs of soil erosion

Abstract: The aim of this study was a survey of the estimated costs of soil erosion, an issue of fundamental importance in view of the current worldwide discussions on sustainability. A list was drawn up of research papers on erosion (on-site and offsite effects) and their respective costs. The estimates indicate the amount of resources spent in the process of soil degradation, raising a general awareness of the need for soil conservation. On-site costs affect the production units directly, while off-site costs create a burden borne by the environment, economy and society. In addition, estimating the costs of soil erosion should be effective to alert the agricultural producers, society and government for the need for measures that can be implemented to bring erosion under control. Among the various estimates of soil erosion costs between 1933 a 2010, the highest figure was 45.5 billion dollars a year for the European Union. In the United States, the highest figure was 44 billion dollars a year. In Brazil, estimates for the state of Parana indicate a value of 242 million dollars a year, and for the state of Sao Paulo, 212 million dollars a year. These figures show, above all, that conservation measures must be implemented if crop and livestock farming production are to be sustainable.