Global climate change and dengue

Abstract

Perhaps one of the most discussed scientific issues regarding the environment nowadays is global climate change. Numerous scientists around the world are putting in tremendous efforts trying to understand several aspects of this worldwide phenomenon that will affect human life on this planet. Actually, various studies point out that the effects of climate change can already be felt in some areas and are starting to concern many governments. Those authors have focused their study in a sediment core raised from the middle of the Márcio lake, situated in Amapá. This region is located about 10 km from the Amazon River and is presently inhabited by a community of former slaves that established small settlements starting in the XVIII century. Toledo and Bush analyzed the core samples for "fossil" pollen and charcoal records and were able to determine an abrupt change of vegetation surrounding the lake about 5000 years ago. Furthermore, they show that approximately at that time a great impact on the environment occurred, which might have been caused by a combination of factors, including human occupation.There is another paper of this issue of the AABC that provides information about a current problem that is being intensively discussed in the Brazilian society: dengue. Particularly in Rio de Janeiro, this human pathogen that is transmitted by infected mosquitoes is of great concern, taking epidemic proportions, apparently spreading to other regions of the country. Gisela F. Trindade and colleagues from the Fundação Oswaldo Cruz have studied the replication of some flaviviruses -including dengue viruses, in rhesus monkeys. Their results might be another step contributing to the development of vaccines against dengue and other related diseases.

Holocene coastal vegetation changes at the mouth of the Amazon River

“…In fact, during the late Holocene local and regional controlling factors become more perceptible. Forces such as precipitation, which strongly influences run-off and river discharge, can result in local "eustatic" sea-level variations (e.g., Mörner, 1996) and significant salinity gradient changes along estuaries (e.g., Lara and Cohen, 2006).…”