Mitochondrial genomic divergence in coelacanths (Latimeria): slow rate of evolution or recent speciation?

Dating the divergence between the two known living species of coelacanths has remained a difficult issue because of the very ancient origin of this lineage of fish, which is more closely related to tetrapods than to other fishes. We sequenced the complete mitochondrial genome of a recently captured individual of the Indonesian coelacanth in order to solve this issue. Using an approach based on loglinear models, we studied the molecular divergence between the two species of coelacanths and three other pairs of species, one that has diverged recently (Pan) and two that have diverged more distantly in the past. The loglinear models showed that the divergence between the two species of coelacanths is not significantly different from the two species of Pan. A detailed gene by gene analysis of the patterns of nucleotide and amino acid substitutions between these two pairs of species further supports the similarity of these divergences. On the other hand, a molecular dating analysis suggested a much older origin of the two coelacanth species (between 20 and 30 million years ago). We discuss the potential reasons for this discrepancy. The analysis of new individuals of the Indonesian coelacanth will certainly help to solve this issue.     

Shifting cultivation in peatlands

Transboundary haze pollution from smoke from land preparation fires has become a perennial problem in Indonesia, especially in the last 10 years during the dry season. Most of that smoke originates from illegal land preparation fires for oil palm and industrial forest plantation as well as from shifting cultivation, which is usually blamed for the smoke. In order to understand the role of fire in shifting cultivation areas dominated by peat soils, research was conducted during the dry season of 2001 on land belonging to the community of Pelalawan village, Pelalawan district, Riau province, Indonesia. The research showed that burning did not affect all peat areas equally. No peat was burned on a fibric site, while burning on a hemic site varied in depth from 6.0 cm to 12.6 cm, and on a sapric site from 15.4 cm to 31.9 cm. Further, on the fibric site only phosphorus increased significantly following burning, while on the hemic only the base saturation increased; on the sapric site, however, both base saturation and phosphorus increased compared to the condition before burning. These data show that if fire is continues to be used for land preparation in peat areas, peat becomes critically endangered.     

Decomposition kinetics of dimethyl methylphospate(chemical agent simulant) by supercritical water oxidation

Supercritical water oxidation （SCWO） has been drawing much attention due to effectively destroy a large variety of high-risk wastes resulting from munitions demilitarization and complex industrial chemical. An important design consideration in the development of supercritical water oxidation is the information of decomposition rate. In this paper, the decomposition rate of dimethyl methylphosphonate（DMMP）, which is similar to the nerve agent VX and GB（Sarin） in its structure, was investigated under SCWO conditions. The experiments were performed in an isothermal tubular reactor with a H2O2 as an oxidant. The reaction temperatures were ranged from 398 to 633℃ at a fixed pressure of 24 MPa. The conversion of DMMP was monitored by analyzing total organic carbon （TOC） on the liquid effluent samples. It is found that the oxidative decomposition of DMMP proceeded rapidly and a high TOC decomposition up to 99.99% was obtained within 11 s at 555℃. On the basis of data derived from experiments, a global kinetic equation for the decomposition of DMMP was developed. The model predictions agreed well with the experimental data.     

Supercritical water oxidation for the destruction of toxic organic wastewaters： A review

The destruction of toxic organic wastewaters from munitions demilitarization and complex industrial chemical clearly becomes an overwhelming problem if left to conventional treatment processes. Two options, incineration and supercritical water oxidation （SCWO）, exist for the complete destruction of toxic organic wastewaters. Incinerator has associated problems such as very high cost and public resentment; on the other hand, SCWO has proved to be a very promising method for the treatment of many different wastewaters with extremely efficient organic waste destruction 99.99% with none of the emissions associated with incineration. In this review, the concepts of SCWO, result and present perspectives of application, and industrial status of SCWO are critically examined and discussed.     

Assessment of carbon leakage in multiple carbon-sink projects: a case study in Jambi Province,Indonesia

Rehabilitation of degraded forest land through implementation of carbon-sink projects can increase terrestrial carbon (C) stock. However, carbon emissions outside the project boundary, which is commonly referred to as leakage, may reduce or negate the sequestration benefits. This study assessed leakage from carbon-sink projects that could potentially be implemented in the study area comprised of 11 sub-districts in the Batanghari District, Jambi Province, Sumatra, Indonesia. The study estimates the probability of a given land use/cover being converted into other uses/cover, by applying a logit model. The predictor variables were: proximity to the center of the land use area, distance to transportation channel (road or river), area of agricultural land, unemployment (number of job seekers), job opportunities, population density and income. Leakage was estimated by analyzing with and without carbon-sink projects scenarios. Most of the predictors were estimated as being significant in their contribution to land use cover change. The results of the analysis show that leakage in the study area can be large enough to more than offset the project’s carbon sequestration benefits during the period 2002–2012. However, leakage results are very sensitive to changes of carbon density of the land uses in the study area. By reducing C-density of lowland and hill forest by about 10% for the baseline scenario, the leakage becomes positive. Further data collection and refinement is therefore required. Nevertheless, this study has demonstrated that regional analysis is a useful approach to assess leakage.     

Nanobiosensor approaches for pollutant monitoring

Environmental Chemistry Letters - The presence of pollutants at trace levels in the environment is a major health issue, but there are actually few rapid analytical techniques that meet the growing...     

Effects of cadmium on metallothionein and histology in gills of tilapia (Oreochromis niloticus) at different salinities

The objectives of this study were to evaluate the effects of sublethal cadmium concentrations on the levels of cadmium, metallothionein (MT) and histological changes in gills of East Java strain tilapia (Oreochromis niloticus) at different salinity levels. The levels of cadmium in control gills were not significantly different at 0, 5 and 10 practical salinity unit (PSU). The cadmium concentrations in gills of cadmium-exposed fish were significantly higher at 0 PSU than at 5, 10 and 15 PSU. The MT concentrations in control gills were not significantly different at 0, 5, and 10 PSU. The MT concentrations of cadmium-exposed fish were significantly higher than those in respective control groups at 0, 5 and 10 PSU. Significant gill damage occurred in fish exposed to cadmium at lower salinity. The epithelial lifting was noted at gills of fish exposed to 2.5 mg/L of cadmium at 0 PSU, and telangiectasis was observed at gills exposed to 5 mg/L of cadmium at 0 PSU. The level of gill damage decreased with increasing salinity of media. The increased MT and histological changes in gills of our findings could be a protective response of animals to toxic effect of cadmium.     

Effect of cadmium on survival and osmoregulation of various developmental stages of the shrimp Penaeus japonicus (Crustacea: Decapoda)

The object of this study was to evaluate the acute toxicity of cadmium in different post-embryonic stages of the penaeid shrimp Penaeus japonicus (Bate, 1888) and to determine the effect of sublethal cadmium on the osmoregulatory capacity used as an indicator of physiological condition. Tolerance to cadmium increases with the developmental stage. The least tolerant stages are the nauplii (48 h LC₅₀: 124 g Cd l^-1) and the zoeae (96 h LC₅₀: 10 to 30 g Cd l^-1). The most tolerant stages are the postlarvae (96 h LC₅₀: 200 to 3500 Cd l^-1) and juveniles (96 h LC₅₀: 5500 g Cd l^-1). In juvenile shrimp, 2000 g Cd l^-1 significantly reduce hypo- and hyper-OC. The effect of cadmium on hypo- and hyper-osmoregulatory capacity illustrates a dose- and time-dependent response. Surviving shrimp recover their hypo-osmoregulatory capacity after 6 d of readaptation in cadmium-free seawater.     

Hydrothermal decomposition of pentachlorophenol in subcritical and supercritical water with sodium hydroxide addition

Hydrothermal decomposition of pentachlorophenol （PCP, C6HC150）, as the probable human carcinogen, was investigated in a tubular reactor under subcritical and supercritical water with sodium hydroxide （NaOH） addition. The experiments were conducted at a temperature range of 30（0-420℃ and a fixed pressure of 25 MPa, with a residence time that ranged from 10 s to 70 s. Under the reaction conditions, the initial PCP concentrations were varied from 0.25 to 1.39 mmol/L, and the NaOH concentrations were varied from 2.5 to 25 times of the concentrations of PCP. The result of this study showed that PCP conversion in supercritical water was highly dependent on the reaction temperature, residence time, and NaOH concentration. PCP conversion in subcritical water is, however, only dependent on reaction temperature. NaOH concentration and residence times were found to have little effect on PCP conversion in subcritical condition. It was found that NaOH concentration affected the dechlorinations of PCP in the supercritical water. The intermediates detected were proposed to be tetrachlorophenol and trichlorophenol, respectively.