Abstract: Summary While around 20% of the Amazonian forest has been cleared for pastures and agriculture, one fourth of the remaining forest is dedicated to wood production [1]. Most of these production forests have been or will be selectively harvested for commercial timber, but recent studies show that even soon after logging, harvested stands retain much of their tree-biomass carbon and biodiversity [2,3]. Comparing species richness of various animal taxa among logged and unlogged forests across the tropics, Burivalova et al.[4] found that despite some variability among taxa, biodiversity loss was generally explained by logging intensity (the number of trees extracted). Here, we use a network of 79 permanent sample plots (376 ha total) located at 10 sites across the Amazon Basin [5] to assess the main drivers of time-to-recovery of post-logging tree carbon (Table S1). Recovery time is of direct relevance to policies governing management practices (i.e., allowable volumes cut and cutting cycle lengths), and indirectly to forest-based climate change mitigation interventions. © 2015 Elsevier Ltd.

Abstract: Black pod rot, caused by Stramenopiles of the genus Phytophthora, leads to serious production losses in all cocoa growing zones. In order to reduce the impact of these pests, preference is given to genetic control using resistant varieties, and sources of resistance are actively being sought, particularly in wild cacao trees. Surveys were undertaken in the natural cacao tree populations of south-eastern French Guiana between 1985 and 1995 and an abundant amount of plant material belonging to a particular genetic group, the “Guiana” group, was collected. A great deal of work has shown the merits of this genetic group as a source of resistance to Phytophthora palmivora and megakarya. We describe here the results of a global study to assess the resistance of the 186 clones in the “Guiana” group “core collection” to a Guianese strain of Phytophthora capsici (strain Reg 2-6). This study, which used an efficient methodology (fifteen series of tests on leaf discs and a statistical test adapted to the ordinal nature of the basic data), showed that the “Guiana” genetic group is a major source of resistance to P.capsici. Strain Reg 2-6 proves to be particularly virulent, as the Scavina 6 control, an international reference for resistance to Phytophthora, is not resistant to it. However, 24 clones of the “Guiana” group are, and 92 have proved to be more resistant than Scavina 6, thereby showing the interest of the group in genetically controlling P.capsici.Thus, of the clones in the Guiana group that are more resistant to P.capsici than Scavina 6, some, which are also resistant to P.palmivora and/or Phytophthora megakarya, and also displaying some other notable qualities, could be incorporated into cocoa genetic improvement programmes in countries where P.capsici is rife on cacao trees.

Abstract: A comparative study of 9H-pyrido[3,4-b]indole (norharmane) and 1-methyl-9H-pyrido[3,4-b]indole (harmane) as inhibitors for C38 steel corrosion in 1 M HCl solution at 25 degrees C was carried out. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behavior in the absence and presence of different concentrations of these inhibitors. The OCP as a function of time were also established. Cathodic and anodic polarization curves show that norharmane and harmane are a mixed-type inhibitors. Adsorption of indole derivatives on the C38 steel surface, in 1 M HCl solution, follows the Langmuir adsorption isotherm model. The Delta G degrees(ads) values were calculated and discussed. The potential of zero charge (PZC) of the C38 steel in inhibited solution was studied by the EIS method, and a mechanism for the adsorption process was proposed. Raman spectroscopy confirmed that indole molecules strongly adsorbed onto the steel surface. The electronic properties of indole derivates, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR). (C) 2010 Elsevier Ltd. All rights reserved.

Abstract: The inhibition effect of alkaloids extract from Oxandra asbeckii plant (OAPE) on the corrosion of C38 steel in 1 M hydrochloric acid solution has been investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The corrosion inhibition efficiency increases on increasing plant extracts concentration. Cathodic and anodic polarization curves show that OAPE is a mixed-type inhibitor. The effect of temperature on the corrosion behavior of C38 steel in 1 M HCl with and without addition of plant extract was studied in the temperature range 25-55 degrees C. The thermodynamic functions of dissolution and adsorption processes were calculated from experimental polarization data and the interpretation of the results are given. The adsorption of this plant extract on the C38 steel surface obeys the Langmuir adsorption isotherm. Surface analysis (Raman) was also carried out to establish the corrosion inhibitive property of this plant extract in HCl solution. (C) 2010 Elsevier Ltd. All rights reserved.

Abstract: We developed nuclear and plastid single nucleotide polymorphism (SNP) and insertion/deletion (INDEL) markers for Dipteryx species using a combination of restriction associated DNA sequencing (RADSeq) and low coverage MiSeq genome sequencing. Of the total 315 loci genotyped using a MassARRAY platform, 292 loci were variable and polymorphic among the 73 sampled individuals from French Guiana, Brasil, Peru, and Bolivia. A final set of 56 nuclear SNPs, 26 chloroplast SNPs, 2 chloroplast INDELs, and 32 mitochondrial SNPs identifying significant population structure was developed. This set of loci will be useful for studies on population genetics of Dipteryx species in Amazonia.