Three-year measurement of methane emission from an Indonesian paddy field

Yearly and seasonal (rainy and dry seasons) variations of CH₄ emission from a Sumatra paddy field were measured for 3 years. The mean CH₄ emission rates during the growth period were in the range of 16.0–26.1 mg CH₄ m^-2 h^-1 for the chemical fertilizer plots and 23.3–34.9 mg CH₄ m^-2 h^-1 for the plots with rice straw application, respectively. The increase in the amounts of CH₄ emission by rice straw application were from 1.3 to 1.6 times. There was no significant difference in the mean CH₄ emission rates between rainy and dry seasons.Total amounts of CH₄ emitted during the period of rice growth were in the ranges of 29.5–48.2 and 43.0–64.6 g CH₄ m^-2 for the plots applied with chemical fertilizer and those with rice straw application, respectively. Nearly the same amounts of CH₄ were emitted in the first and second half of the growth period, irrespective of rice straw application.     

Mangrove blue carbon stocks and dynamics are controlled by hydrogeomorphic settings and land‐use change

Globally, carbon‐rich mangrove forests are deforested and degraded due to land‐use and land‐cover change (LULCC). The impact of mangrove deforestation on carbon emissions has been reported on a global scale; however, uncertainty remains at subnational scales due to geographical variability and field data limitations. We present an assessment of blue carbon storage at five mangrove sites across West Papua Province, Indonesia, a region that supports 10% of the world's mangrove area. The sites are representative of contrasting hydrogeomorphic settings and also capture change over a 25‐years LULCC chronosequence. Field‐based assessments were conducted across 255 plots covering undisturbed and LULCC‐affected mangroves (0‐, 5‐, 10‐, 15‐ and 25‐year‐old post‐harvest or regenerating forests as well as 15‐year‐old aquaculture ponds). Undisturbed mangroves stored total ecosystem carbon stocks of 182–2,730 (mean ± SD: 1,087 ± 584) Mg C/ha, with the large variation driven by hydrogeomorphic settings. The highest carbon stocks were found in estuarine interior (EI) mangroves, followed by open coast interior, open coast fringe and EI forests. Forest harvesting did not significantly affect soil carbon stocks, despite an elevated dead wood density relative to undisturbed forests, but it did remove nearly all live biomass. Aquaculture conversion removed 60% of soil carbon stock and 85% of live biomass carbon stock, relative to reference sites. By contrast, mangroves left to regenerate for more than 25 years reached the same level of biomass carbon compared to undisturbed forests, with annual biomass accumulation rates of 3.6 ± 1.1 Mg C ha^?1 year^?1. This study shows that hydrogeomorphic setting controls natural dynamics of mangrove blue carbon stocks, while long‐term land‐use changes affect carbon loss and gain to a substantial degree. Therefore, current land‐based climate policies must incorporate landscape and land‐use characteristics, and their related carbon management consequences, for more effective emissions reduction targets and restoration outcomes.     

Gibberellin mediates the development of gelatinous fibres in the tension wood of inclined Acacia mangium seedlings

Background and Aims

Gibberellin stimulates negative gravitropism and the formation of tension wood in tilted Acacia mangium seedlings, while inhibitors of gibberellin synthesis strongly inhibit the return to vertical growth and suppress the formation of tension wood. To characterize the role of gibberellin in tension wood formation and gravitropism, this study investigated the role of gibberellin in the development of gelatinous fibres and in the changes in anatomical characteristics of woody elements in Acacia mangium seedlings exposed to a gravitational stimulus.

Methods

Gibberellin, paclobutrazol and uniconazole-P were applied to the soil in which seedlings were growing, using distilled water as the control. Three days after the start of treatment, seedlings were inclined at 45 ° to the vertical and samples were harvested 2 months later. The effects of the treatments on wood fibres, vessel elements and ray parenchyma cells were analysed in tension wood in the upper part of inclined stems and in the opposite wood on the lower side of inclined stems.

Key Results

Application of paclobutrazol or uniconazole-P inhibited the increase in the thickness of gelatinous layers and prevented the elongation of gelatinous fibres in the tension wood of inclined stems. By contrast, gibberellin stimulated the elongation of these fibres. Application of gibberellin and inhibitors of gibberellin biosynthesis had only minor effects on the anatomical characteristics of vessel and ray parenchyma cells.

Conclusions

The results suggest that gibberellin is important for the development of gelatinous fibres in the tension wood of A. mangium seedlings and therefore in gravitropism.     

The Epidemiology,Virology and Clinical Findings of Dengue Virus Infections in a Cohort of Indonesian Adults in Western Java

Background

Dengue has emerged as one of the most important infectious diseases in the last five decades. Evidence indicates the expansion of dengue virus endemic areas and consequently the exponential increase of dengue virus infections across the subtropics. The clinical manifestations of dengue virus infection include sudden fever, rash, headache, myalgia and in more serious cases, spontaneous bleeding. These manifestations occur in children as well as in adults. Defining the epidemiology of dengue in a given area is critical to understanding the disease and devising effective public health strategies.

Methodology/Principal Findings

Here, we report the results from a prospective cohort study of 4380 adults in West Java, Indonesia, from 2000–2004 and 2006–2009. A total of 2167 febrile episodes were documented and dengue virus infections were confirmed by RT-PCR or serology in 268 cases (12.4%). The proportion ranged from 7.6 to 41.8% each year. The overall incidence rate of symptomatic dengue virus infections was 17.3 cases/1,000 person years and between September 2006 and April 2008 asymptomatic infections were 2.6 times more frequent than symptomatic infections. According to the 1997 WHO classification guidelines, there were 210 dengue fever cases, 53 dengue hemorrhagic fever cases (including one dengue shock syndrome case) and five unclassified cases. Evidence for sequential dengue virus infections was seen in six subjects. All four dengue virus serotypes circulated most years. Inapparent dengue virus infections were predominantly associated with DENV-4 infections.

Conclusions/Significance

Dengue virus was responsible for a significant percentage of febrile illnesses in an adult population in West Java, Indonesia, and this percentage varied from year to year. The observed incidence rate during the study period was 43 times higher than the reported national or provincial rates during the same time period. A wide range of clinical severity was observed with most infections resulting in asymptomatic disease. The circulation of all four serotypes of dengue virus was observed in most years of the study.     

Bisleuconothine A,an eburnane–aspidosperma bisindole alkaloid from Leuconotis griffithii

A new bisindole alkaloid, bisleuconothine A (1) consisting of an eburnane–aspidosperma type skeleton, was isolated from the bark of Leuconotis griffithii. The structure including absolute stereochemistry was elucidated on the basis of 2D NMR data and X-ray analysis. Bisleuconothine A (1) showed cell growth inhibitory activity against various human cancer cell lines.     

Enzymatic grafting of functional molecules to the lignin model dibenzodioxocin and lignocellulose material

Laccase-mediated grafting of functional molecules presents an eco-friendly approach to functionalize lignocellulose materials. In this study functional molecules in the form of reactive phenolic amines, hydrophobicity enhancing fluorophenols and selected wood preservatives, were for the first time successfully coupled onto the lignin model compound dibenzodioxocin (Db) as demonstrated by HPLC-MS analysis. A 1:1-coupling was demonstrated for various combinations including Db and tyramine (m/z 620.5), Db and 3-O-methyldopamine (m/z 650.5), Db and 4-hydroxy-3-methoxybenzylamine (m/z 636.5), Db and 4-fluoro-2-methylphenol (m/z 609.5), and Db and 2-phenylphenol (m/z 653.5). Fungal laccases from Trametes hirsuta and T. villosa were more efficient in mediating the coupling of tyramine to dibenzodioxocin and beech (Fagus sylvatica) wood than a Bacillus sp. laccase with lower redox potential. This work presents for the first time a model for functionalizing of lignocellulose using the lignin model dibenzodioxocin.     

Enzymatic synthesis of lignin-siloxane hybrid functional polymers

This study combines the properties of siloxanes and lignin polymers to produce hybrid functional polymers that can be used as adhesives, coating materials, and/or multifunctionalized thin-coating films. Lignin-silica hybrid copolymers were synthesized by using a sol-gel process. Laccases from Trametes hirsuta were used to oxidize lignosulphonates to enhance their reactivity towards siloxanes and then were incorporated into siloxane precursors undergoing a sol-gel process. In vitro copolymerization studies using pure lignin monomers with aminosilanes or ethoxytrimethylsilane and analysis by 2?Si NMR spectroscopy revealed hybrid products. Except for kraft lignin, an increase in lignin concentration positively affected the tensile strength in all samples. Similarly, the viscosity generally increased in all samples with increasing lignin concentration and also affected the curing time.     

Secondary metabolism in tobacco

Tobacco has been quite well studied phytochemically, more than 2500 compounds have been identified. Here, the secondary metabolism in tobacco will be reviewed in a biosynthetic perspective. Major groups of compounds which have extensively been studied are the isoprenoids, alkaloids, cinnamoylputrescines, flavonoids, and anthocyanins. Their biosynthetic pathways and its regulation, and their occurrence in cell cultures and in intact plants will be discussed.