Moving beyond the concept of "primary forest" as a metric of forest environment quality.

The United Nations Food and Agriculture Organization (FAO) has been reporting country-level area in primary forests in its Global Forest Resource Assessment since 2005. The FAO definition of a primary forest (naturally regenerated forest of native species where there are no clearly visible indications of human activities and the ecological processes are not significantly disturbed) is generally accepted as authoritative and is being used in policy making. However, problems with this definition undermine our capacity to obtain globally coherent estimates. In addition, the current reporting on primary forests fails to consider the complementarily of non-primary forests toward the maintenance of ecosystem services. These issues undermine the appropriate tracking of changes in primary and non-primary forests, and the assessment of impacts of such changes on ecosystem services. We present the case for an operational reconsideration of the primary forest concept and discuss how alternatives or supplements might be developed.

Formation of methemoglobin by photoactivation of nitrofurantoin or of 5-nitrofurfural in rats exposed to UV-A light.

The antibacterial drug nitrofurantoin (NFT) is notorious for causing hemolytic anemia, which may be related to the methemoglobinemia, another side-effect of NFT. As NFT is photolabile, and nitrite, well known as a MetHb generator, is an important photoproduct of NFT, it seems not unlikely that light is a cause of NFT-induced MetHb formation. When rats were irradiated with UV-A immediately after oral NFT administration, the amount of MetHb significantly increased: 0.97 +/- 0.37% n = 36 (P less than 0.001 Student's t-test, control value: 0.5%). An increase in MetHb was also observed with rats simultaneously exposed to UV-A and the major photodecomposition product of NFT, viz. 5-nitrofurfural. In addition in vitro experiments proved the formation of MetHb as a result of photoactivation of NFT. Nitrite, photochemically formed from nitrofurfural and from the metabolite nitrofuroic acid, plays an important role. A dark reaction of the other photoproduct, nitrofurfural, with hemoglobin also appeared to cause a considerable amount of MetHb in vitro. However, because of rapid deactivation of nitrofurfural by either photodecomposition or metabolism, this dark reaction is not expected to contribute to the in vivo MetHb formation.