33 research outputs found

    Nut production in Bertholletia excelsa across a logged forest mosaic: implications for multiple forest use

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    Although many examples of multiple-use forest management may be found in tropical smallholder systems, few studies provide empirical support for the integration of selective timber harvesting with non-timber forest product (NTFP) extraction. Brazil nut (Bertholletia excelsa, Lecythidaceae) is one of the world’s most economically-important NTFP species extracted almost entirely from natural forests across the Amazon Basin. An obligate out-crosser, Brazil nut flowers are pollinated by large-bodied bees, a process resulting in a hard round fruit that takes up to 14 months to mature. As many smallholders turn to the financial security provided by timber, Brazil nut fruits are increasingly being harvested in logged forests. We tested the influence of tree and stand-level covariates (distance to nearest cut stump and local logging intensity) on total nut production at the individual tree level in five recently logged Brazil nut concessions covering about 4000 ha of forest in Madre de Dios, Peru. Our field team accompanied Brazil nut harvesters during the traditional harvest period (January-April 2012 and January-April 2013) in order to collect data on fruit production. Three hundred and ninety-nine (approximately 80%) of the 499 trees included in this study were at least 100 m from the nearest cut stump, suggesting that concessionaires avoid logging near adult Brazil nut trees. Yet even for those trees on the edge of logging gaps, distance to nearest cut stump and local logging intensity did not have a statistically significant influence on Brazil nut production at the applied logging intensities (typically 1–2 timber trees removed per ha). In one concession where at least 4 trees ha-1 were removed, however, the logging intensity covariate resulted in a marginally significant (0.09) P value, highlighting a potential risk for a drop in nut production at higher intensities. While we do not suggest that logging activities should be completely avoided in Brazil nut rich forests, when a buffer zone cannot be observed, low logging intensities should be implemented. The sustainability of this integrated management system will ultimately depend on a complex series of socioeconomic and ecological interactions. Yet we submit that our study provides an important initial step in understanding the compatibility of timber harvesting with a high value NTFP, potentially allowing for diversification of forest use strategies in Amazonian Perù

    Conservation performance of different conservation governance regimes in the Peruvian Amazon

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    State-controlled protected areas (PAs) have dominated conservation strategies globally, yet their performance relative to other governance regimes is rarely assessed comprehensively. Furthermore, performance indicators of forest PAs are typically restricted to deforestation, although the extent of forest degradation is greater. We address these shortfalls through an empirical impact evaluation of state PAs, Indigenous Territories (ITs), and civil society and private Conservation Concessions (CCs) on deforestation and degradation throughout the Peruvian Amazon. We integrated remote-sensing data with environmental and socio-economic datasets, and used propensity-score matching to assess: (i) how deforestation and degradation varied across governance regimes between 2006–2011; (ii) their proximate drivers; and (iii) whether state PAs, CCs and ITs avoided deforestation and degradation compared with logging and mining concessions, and the unprotected landscape. CCs, state PAs, and ITs all avoided deforestation and degradation compared to analogous areas in the unprotected landscape. CCs and ITs were on average more effective in this respect than state PAs, showing that local governance can be equally or more effective than centralized state regimes. However, there were no consistent differences between conservation governance regimes when matched to logging and mining concessions. Future impact assessments would therefore benefit from further disentangling governance regimes across unprotected land.This work was supported by the Economic and Social Research Council (grant number ES/I019650/1); Cambridge Political Economy Society; Cambridge Philosophical Society; St John’s College; and the Geography Department at the University of Cambridge

    Posttraumatische longhernia

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    Analysis of changes in triacylglycerol ratios in mouse liver and plasma in response to a liver X receptor agonist

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    An LC-MS method was developed for the analysis of triacylglycerols (TAG) in mouse liver extracts and plasma samples. C57 Mice were treated with two LXR agonists that have been shown to upregulate TAGs, T0901317 (T1317) or Org 264693 and compared to vehicle dosed animals. The dose used was 30 mg kg(-1), once daily, with three different dose regimes; 24 H, 48 H and 5 day. The TAG ratios measured were C52: 2/C54: 3 and C52: 3/C54: 4, which corresponded to a decrease in the palmitate and an increase in oleate composition of the TAGs. A significant change in the C52: 2/C54: 3 ratio was observed with all dose regimes and a good correlation was obtained between liver and plasma samples. In a separate study, the same compounds were dosed to LXR alpha and LXR beta knock-out (KO) mice at 30 mg kg(-1), once daily, for 5 days. The LXR beta KO mice showed similar TAG ratio changes to the C57 mice, whereas the LXR alpha KO mice showed no change in TAG ratios versus vehicle dosed animals. Measurements of lipid liability in response to an LXR agonist are typically made by measuring total liver TAG levels, which here, only showed a significant effect after the 48 H and 5 day dose regimes. By using a ratio measurement analysis could be performed on plasma samples, greatly simplifying the sample preparation procedure, without the requirement for either calibration curves or an internal standard
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