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Restoring aboveground carbon and biodiversity: a case study from the Nile basin, Ethiopia
Wolde Mekuria,Simon Langan,Robyn Johnston,Beyene Belay,Dagninet Amare,Tadesse Gashaw,Abeyou Wale,Gizaw Desta,Andrew Noble 한국산림과학회 2015 Forest Science And Technology Vol.11 No.2
In Ethiopia, exclosures in landscapes have become increasingly important to improving ecosystem services and reversing biodiversity losses. The present study was conducted in Gomit watershed, northern Ethiopia, to: (i) investigate the changes in vegetation composition, diversity and aboveground biomass and carbon following the establishment of exclosures; and (ii) analyse the economic returns of aboveground carbon sequestration and assess the perception of local communities on land degradation and exclosures. A space-for-time substitution approach was used to detect the changes in aboveground carbon, species composition, and diversity. Exclosures of 1-, 2-, 3-, 4-, 5-, and 7-years-old and a communal grazing land were selected. Household surveys, key informant interviews, and a financial analysis were used to assess the perception of local communities and the value of exclosure impacts, respectively. Significant (P D 0.049) differences in species diversity and considerable increases in aboveground carbon (ranged from 0.6 to 4.2 t C ha ¡1), CO2 storage (varied between 2.1 and 15.3 t CO2 ha ¡1), woody species composition, and richness (ranged from five to 28) were observed following the establishment of exclosures. Exclosures generated temporary certified emission reductions (tCER) of 3.4, 2.1, 7.5, 12.6, 12.5, and 15.3 Mg CO2 ha ¡1 after 1, 2, 3, 4, 5, and 7 years, respectively. The net present value (NPV) of the aboveground carbon sequestered in exclosures ranged from US$6.6 to US$37.0 per hectare and increased with exclosure duration. At a watershed level, 51.4 Mg C ha ¡1 can be sequestered, which represents 188.6 Mg CO2 ha ¡1, resulting in tCER of 139.4 Mg CO2 ha ¡1 and NPV of US$478.3 per hectare. This result would suggest that exclosures can potentially improve local communities’ livelihoods beyond rehabilitating degraded lands if carbon stored in exclosures is traded. Communities in the watershed demonstrated that exclosures are effective in restoring degraded lands and they are benefiting from increased fodder production and reduced impacts of soil erosion. However, the respondents are also concerned over the sustainability of exclosure land management, as further expansion of exclosures aggravates degradation of remaining communal grazing lands and causes fuel wood shortages. This suggests that the sustainability of exclosure land management can be attained only if these critical concerns are addressed by a joint effort among government agencies, nongovernmental organizations, and communities.
A guide to studying human hair follicle cycling <i>in vivo</i>
Oh, Ji Won,Kloepper, Jennifer,Langan, Ewan A.,Kim, Yongsoo,Yeo, Joongyeub,Kim, Min Ji,Hsi, Tsai-Ching,Rose, Christian,Yoon, Ghil Suk,Lee, Seok-Jong,Seykora, John,Kim, Jung Chul,Sung, Young Kwan,Kim, M Nature Publishing Group 2016 The Journal of investigative dermatology Vol.136 No.1
<P>Hair follicles (HFs) undergo life-long cyclical transformations, progressing through stages of rapid growth (anagen), regression (catagen), and relative “quiescence” (telogen). Since HF cycling abnormalities underlie many human hair growth disorders, the accurate classification of individual cycle stages within skin biopsies is clinically important and essential for hair research. For preclinical human hair research purposes, human scalp skin can be xenografted onto immunocompromised mice to study human HF cycling and manipulate long-lasting anagen <I>in vivo</I>. While available for mice, a comprehensive guide on how to recognize different human hair cycle stages <I>in vivo</I> is lacking. Here, we present such a guide, which uses objective, well-defined, and reproducible criteria and integrates simple morphological indicators with advanced, (immuno)-histochemical markers. This guide also characterizes human HF cycling in xenografts and highlights the utility of this model for <I>in vivo</I> hair research. Detailed schematic drawings and representative micrographs provide examples of how best to identify human HF stages, even in sub-optimally sectioned tissue, and practical recommendations are given for designing human-on-mouse hair cycle experiments. Thus, this guide seeks to offer a benchmark for human hair cycle stage classification, for both hair research experts and newcomers to the field.</P>
Cho, Dae Won,Latham, John A.,Park, Hea Jung,Yoon, Ung Chan,Langan, Paul,Dunaway-Mariano, Debra,Mariano, Patrick S. American Chemical Society 2011 Journal of organic chemistry Vol.76 No.8
<P>New types of tetrameric lignin model compounds, which contain the common β-O-4 and β-1 structural subunits found in natural lignins, have been prepared and carbon−carbon bond fragmentation reactions of their cation radicals, formed by photochemical (9,10-dicyanoanthracene) and enzymatic (lignin peroxidase) SET-promoted methods, have been explored. The results show that cation radical intermediates generated from the tetrameric model compounds undergo highly regioselective C−C bond cleavage in their β-1 subunits. The outcomes of these processes suggest that, independent of positive charge and odd-electron distributions, cation radicals of lignins formed by SET to excited states of sensitizers or heme-iron centers in enzymes degrade selectively through bond cleavage reactions in β-1 vs β-O-4 moieties. In addition, the findings made in the enzymatic studies demonstrate that the sterically large tetrameric lignin model compounds undergo lignin peroxidase-catalyzed cleavage via a mechanism involving preliminary formation of an enzyme−substrate complex.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/joceah/2011/joceah.2011.76.issue-8/jo200253v/production/images/medium/jo-2011-00253v_0002.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jo200253v'>ACS Electronic Supporting Info</A></P>