31 research outputs found
Ajuste de uma função de afilamento via minimização da soma dos desvios absolutos
Os inventários florestais para múltiplos produtos requerem estimativas exatas do diâmetro, comprimento e volume de cada produto. As equações de afilamento têm sido usadas para descrever precisamente a forma da árvore uma vez que estas funções fornecem estimativas de diâmetro a qualquer altura ou de altura em qualquer diâmetro. Este trabalho aplica um modelo de programação por metas para estimar os parâmetros de duas equações de afilamento para descrever a forma do tronco de árvores individuais. O modelo de programação por metas gera parâmetros que minimizam a soma dos desvios absolutos (MOTAD). Esses parâmetros gerados pelo método MOTAD foram comparados aos parâmetros gerados pelo método dos mÃnimos quadrados ordinários (OLS). A análise se baseou em dados de cubagem de 178 árvores obtidas em plantios clonais de eucaliptos conduzidos na região sul da Bahia. Os valores dos parâmetros estimados por ambos os métodos de ajuste para as duas funções de afilamento mostraram-se muito semelhantes. Não houve diferença significativa entre os indicadores usados para avaliar a qualidade dos parâmetros estimados pelos dois métodos de ajuste. Os métodos OLS e MOTAD mostraram-se igualmente precisos na estimação de diâmetros e volumes com casca e sem casca.Multiple product inventories of forests require accurate estimates of the diameter, length and volume of each product. Taper functions have been used to precisely describe tree form, once they provide estimates for the diameter at any height or the height at any diameter. This study applied a goal programming technique to estimate the parameters of two taper functions to describe individual tree forms. The goal programming formulation generates parameters that minimize total absolute deviations (MOTAD). These parameters generated by the MOTAD method were compared to those of ordinary least squares (OLS) method. The analysis used a set of 178 trees cut from cloned eucalyptus plantations in the Southern part of the state of Bahia, Brazil. The values of the estimated parameters for the two taper functions resulted very similar when the two methods were compared. There was no significant difference between the two fitting methods according to the statistics used to evaluate the quality of the generated estimates. OLS and MOTAD resulted equally precise in the estimation of diameters and volumes outside and inside bark
Using supply chain data to monitor zero deforestation commitments: an assessment of progress in the Brazilian soy sector
Zero deforestation commitments (ZDCs) are voluntary initiatives where companies or countries pledge to eliminate deforestation from their supply chains. These commitments offer much promise for sustainable commodity production, but are undermined by a lack of transparency about their coverage and impacts. Here, using state-of-the-art supply chain data, we introduce an approach to evaluate the impact of ZDCs, linking traders and international markets to commodity-associated deforestation in the sub-national jurisdictions from which they source. We focus on the Brazilian soy sector, where we find that ZDC coverage is increasing, but under-represents the Cerrado biome where most soy-associated deforestation currently takes place. Though soy-associated deforestation declined in the Amazon after the introduction of the Soy Moratorium, we observe no change in the exposure of companies or countries adopting ZDCs to soy-associated deforestation in the Cerrado. We further assess the formulation and implementation of these ZDCs and identify several systematic weaknesses that must be addressed to increase the likelihood that they achieve meaningful reductions in deforestation in future. As the 2020 deadline for several of these commitments approaches, our approach can provide independent monitoring of progress toward the goal of ending commodity-associated deforestation
Abstracts from the 8th International Conference on cGMP Generators, Effectors and Therapeutic Implications
This work was supported by a restricted research grant of Bayer AG
Plasmonically amplified bioassay – Total internal reflection fluorescence vs. epifluorescence geometry
his paper investigates plasmonic amplification in two commonly used optical configurations for fluorescence readout of bioassays – epifluorescence (EPF) and total internal reflection fluorescence (TIRF). The plasmonic amplification in the EPF configuration was implemented by using crossed gold diffraction grating and Kretschmann geometry of attenuated total reflection method (ATR) was employed in the TIRF configuration. Identical assay, surface architecture for analyte capture, and optics for the excitation, collection and detection of emitted fluorescence light intensity were used in both TIRF and EPF configurations. Simulations predict that the crossed gold diffraction grating (EPF) can amplify the fluorescence signal by a factor of 102 by the combination of surface plasmon-enhanced excitation and directional surface plasmon-coupled emission in the red part of spectrum. This factor is about order of magnitude higher than that predicted for the Kretschmann geometry (TIRF) which only took advantage of the surface plasmon-enhanced excitation. When applied for the readout of sandwich interleukin 6 (IL-6) immunoassay, the plasmonically amplified EPF geometry designed for Alexa Fluor 647 labels offered 4-times higher fluorescence signal intensity compared to TIRF. Interestingly, both geometries allowed reaching the same detection limit of 0.4 pM despite of the difference in the fluorescence signal enhancement. This is attributed to inherently lower background of fluorescence signal for TIRF geometry compared to that for EPF which compensates for the weaker fluorescence signal enhancement. The analysis of the inflammation biomarker IL-6 in serum at medically relevant concentrations and the utilization of plasmonic amplification for the fluorescence measurement of kinetics of surface affinity reactions are demonstrated for both EPF and TIRF readout
Latin American and Caribbean Forests in the 2020s: Trends, Challenges, and Opportunities
This monograph presents expert assessments of four different facets of Latin American and Caribbean (LAC) forests at the start of the 2020s. In Chapter 1, Dan Nepstad and coauthors distill lessons from case studies of the application of various approaches to forest conservation and restoration in four countries: Brazil, Costa Rica, Ecuador, and Peru. In Chapter 2, Carlos Nobre and coauthors examine the two-way links between forests and climate change. They summarize what we know about the effects of climate change on forests and human migration in LAC, and the effects of forest loss and degradation on global and regional climate change. In addition, they present case studies of some of these links for Brazil and Costa Rica. In Chapter 3, Brent Sohngen explores LAC forest management, including LAC trends in international trade in timber and bioenergy, sustainable forest management, nontimber forest products, illegal logging, property rights, and climate change as it affects managed forests. In addition, Dr. Sohngen summarizes an original analysis of future timber supply potential using the Global Timber Model. Finally, in Chapter 4, Simone Bauch presents an analysis of the IADBGs experience with forest projects over the past 13 years. Having reviewed IADBG documents on all 99 forest projects approved by bank during this period and interviewed 23 current and former bank staff, Dr. Bauch presents a brief recent history of IADBG forest projects, an overview of the major determinants of project development, and an analysis of trends in forest projects, including their number, funding, objectives, themes, and locations. An Introduction by the editor, Allen Blackman, discusses the broad issues these expert assessment address and summarizes their key findings