Phytochemical Screening and Antioxidant Activity of Selekop (Lepisanthes Amoena) Fruit

Selekop (Lepisanthes amoena (Hassk.) Leenh.) plant leaves are used by the Dayak tribe of East Kalimantan as traditional cosmetics. Selekop fruit is also edible, but not well known. This study was conducted to obtain the phytochemical content and antioxidant assay in flesh, seed and pericarp extracts from the fruit of Selekop. Phytochemical analysis was conducted on ethanol extract for identification of flavonoid, alkaloid, tannin, saponin, triterpenoid and steroid. The antioxidant activity was done by DPPH assay with ascorbic acid as positive control. The flesh contained flavonoid, saponin, and tannin; the seed contained flavonoid, alkaloid, saponin, triterpenoid, and tannin; and the pericarp contained flavonoid, alkaloid, saponin, triterpenoid, and tannin. Analysis of antioxidant activity revealed the following Inhibitory Concentration (IC50 values): 122.51 ppm of flesh, 63.30 ppm of seed, 53.21 ppm of pericarp and 3.06 ppm of ascorbic acid. Based on these results, the ethanol extract of the seed and the flesh had a phytochemical content and antioxidant activity which was better than the flesh extract from Selekop fuit

Overriding water table control on managed peatland greenhouse gas emissions

Global peatlands store more carbon than is naturally present in the atmosphere1,2. However, many peatlands are under pressure from drainage-based agriculture, plantation development and fire, with the equivalent of around 3% of all anthropogenic greenhouse gases emitted from drained peatland3–5. Efforts to curb such emissions are intensifying through the conservation of undrained peatlands and rewetting of drained systems6. Here we report CO2 eddy covariance data from 16 locations and CH4 data from 41 locations in the British Isles, and combine them with published data from sites across all major peatland biomes. We find that the mean annual effective water-table depth (WTDe; that is, the average depth of the aerated peat layer) overrides all other ecosystem- and management-related controls on greenhouse gas fluxes. We estimate that every 10 cm of reduction in WTDe could reduce the net warming impact of CO2 and CH4 emissions (100-year Global Warming Potentials) by at least 3 t CO2e ha-1 yr-1, until WTDe is < 30 cm. Raising water levels further would continue to have a net cooling effect until WTDe is < 10 cm. Our results suggest that greenhouse gas emissions from peatlands drained for agriculture could be greatly reduced without necessarily halting their productive use. Halving WTDe in all drained agricultural peatlands, for example, could reduce emissions by the equivalent of over 1% of global anthropogenic emissions

Structure and function of Spc42 coiled-coils in yeast centrosome assembly and duplication

Centrosomes and spindle pole bodies (SPBs) are membraneless organelles whose duplication and assembly is necessary for bipolar mitotic spindle formation. The structural organization and functional roles of major proteins in these organelles can provide critical insights into cell division control. Spc42, a phosphoregulated protein with an N-terminal dimeric coiled-coil (DCC), assembles into a hexameric array at the budding yeast SPB core, where it functions as a scaffold for SPB assembly. Here, we present in vitro and in vivo data to elucidate the structural arrangement and biological roles of Spc42 elements. Crystal structures reveal details of two additional coiled-coils in Spc42: a central trimeric coiled-coil and a C-terminal antiparallel DCC. Contributions of the three Spc42 coiled-coils and adjacent undetermined regions to the formation of an ∼145 Å hexameric lattice in an in vitro lipid monolayer assay and to SPB duplication and assembly in vivo reveal structural and functional redundancy in Spc42 assembly. We propose an updated model that incorporates the inherent symmetry of these Spc42 elements into a lattice, and thereby establishes the observed sixfold symmetry. The implications of this model for the organization of the central SPB core layer are discussed

BOREAS TF-9 SSA-OBS Tower Flux, Meteorological, and Soil Temperature Data

The BOREAS TF-9 team collected energy, carbon dioxide, and water vapor flux data at the BOREAS SSA-OBS site during the growing season of 1994 and most of the year for 1996. From the winter of 1995 to 1996, soil temperature data were also collected and provided. The data are available in tabular ASCII files