Towards a low carbon economy in the Amazon: the role of land-use policies

Climate change, rising oil prices and the global financial crisis has put sustainability and ‘green growth’ of the economy on the political agenda. While the transition towards a “low carbon” economy in developed countries like in the European Union should mainly be found in renewable energy production, developing countries like Brazil face with high land use emissions which will further rise in the coming decades without proper policy instruments. Deforestation and cattle production are the main sources of land use emissions in Brazil and we expect that these emissions will further rise with liberalisation of agricultural trade. A transition towards a “low carbon” economy in Brazil thus calls for appropriate, and effective land-use policies. Agricultural intensification on one hand can meet the world demand for soy and beef. For example we calculate that increasing the meat content of cattle can reduce emissions from deforestation up to 30%, but intensification may also accelerate further deforestation of Cerrado and Amazon forests. In order to avoid such additional deforestation, large areas of degraded lands have to be taken back into production, which requires large agricultural investments. In addition, (new) economic instruments, monitoring, law enforcement and appropriate conservation policies are also needed to halt further deforestation and biodiversity loss. The recently amended change of the Forest Code policy, for example, is expected to accelerate deforestation further, thus making more difficult to reach mitigation targets for the Brazilian State

High levels of T lymphocyte activation in Leishmania-HIV-1 co-infected individuals despite low HIV viral load

<p>Abstract</p> <p>Background</p> <p>Concomitant infections may influence HIV progression by causing chronic activation leading to decline in T-cell function. In the Americas, visceral (AVL) and tegumentary leishmaniasis (ATL) have emerged as important opportunistic infections in HIV-AIDS patients and both of those diseases have been implicated as potentially important co-factors in disease progression. We investigated whether leishmaniasis increases lymphocyte activation in HIV-1 co-infected patients. This might contribute to impaired cellular immune function.</p> <p>Methods</p> <p>To address this issue we analyzed CD4⁺T absolute counts and the proportion of CD8⁺T cells expressing CD38 in <it>Leishmania</it>/HIV co-infected patients that recovered after anti-leishmanial therapy.</p> <p>Results</p> <p>We found that, despite clinical remission of leishmaniasis, AVL co-infected patients presented a more severe immunossupression as suggested by CD4⁺T cell counts under 200 cells/mm³, differing from ATL/HIV-AIDS cases that tends to show higher lymphocytes levels (over 350 cells/mm³). Furthermore, five out of nine, AVL/HIV-AIDS presented low CD4⁺T cell counts in spite of low or undetectable viral load. Expression of CD38 on CD8⁺T lymphocytes was significantly higher in AVL or ATL/HIV-AIDS cases compared to HIV/AIDS patients without leishmaniasis or healthy subjects.</p> <p>Conclusions</p> <p><it>Leishmania </it>infection can increase the degree of immune system activation in individuals concomitantly infected with HIV. In addition, AVL/HIV-AIDS patients can present low CD4⁺T cell counts and higher proportion of activated T lymphocytes even when HIV viral load is suppressed under HAART. This fact can cause a misinterpretation of these laboratorial markers in co-infected patients.</p

ELISA versus PCR for diagnosis of chronic Chagas disease: systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Most current guidelines recommend two serological tests to diagnose chronic Chagas disease. When serological tests are persistently inconclusive, some guidelines recommend molecular tests. The aim of this investigation was to review chronic Chagas disease diagnosis literature and to summarize results of ELISA and PCR performance.</p> <p>Methods</p> <p>A systematic review was conducted searching remote databases (MEDLINE, LILACS, EMBASE, SCOPUS and ISIWeb) and full texts bibliography for relevant abstracts. In addition, manufacturers of commercial tests were contacted. Original investigations were eligible if they estimated sensitivity and specificity, or reliability -or if their calculation was possible - of ELISA or PCR tests, for chronic Chagas disease.</p> <p>Results</p> <p>Heterogeneity was high within each test (ELISA and PCR) and threshold effect was detected only in a particular subgroup. Reference standard blinding partially explained heterogeneity in ELISA studies, and pooled sensitivity and specificity were 97.7% [96.7%-98.5%] and 96.3% [94.6%-97.6%] respectively. Commercial ELISA with recombinant antigens studied in phase three investigations partially explained heterogeneity, and pooled sensitivity and specificity were 99.3% [97.9%-99.9%] and 97.5% [88.5%-99.5%] respectively. ELISA's reliability was seldom studied but was considered acceptable. PCR heterogeneity was not explained, but a threshold effect was detected in three groups created by using guanidine and boiling the sample before DNA extraction. PCR sensitivity is likely to be between 50% and 90%, while its specificity is close to 100%. PCR reliability was never studied.</p> <p>Conclusions</p> <p>Both conventional and recombinant based ELISA give useful information, however there are commercial tests without technical reports and therefore were not included in this review. Physicians need to have access to technical reports to understand if these serological tests are similar to those included in this review and therefore correctly order and interpret test results. Currently, PCR should not be used in clinical practice for chronic Chagas disease diagnosis and there is no PCR test commercially available for this purpose. Tests limitations and directions for future research are discussed.</p

Track A Basic Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138319/1/jia218438.pd