Model of turbulence penetration into a suspension layer on a sediment bed and effect on vertical solute transfer

The vertical diffusional mass (solute) transfer through a suspended sediment layer, e.g. at the bottom of a lake, reservoir or estuary, by the propagation of velocity fluctuations from above was investigated. The attenuation of the velocity fluctuations in the suspension layer and the associated effect on solute transfer through the suspension layer was simulated. To represent large eddies traveling downstream in water over a high-concentration suspended sediment layer, a streamwise velocity fluctuation moving in downstream direction was imposed along the upper boundary of the suspension layer. Velocity fluctuations and downstream velocity were normalized by the shearvelocity (U_*) at the top of the suspension layer. Streamwise and vertical velocity components inside the suspension layer, were obtained from the 2-D continuity and the Navier–Stokes equations. The persistence of turbulence with depth—as it penetrates from the overlying water into the suspension layer—was found to depend on its amplitude, its period, and on the apparent viscosity of the suspension. The turbulence was found to propagate efficiently into the suspension layer when its frequency is low, and the apparent viscosity of the suspension is high. Effects on vertical mass transfer were parameterized by penetration depth and effective diffusion coefficient, and related to apparent viscosity of the suspension, Schmidt number and shear velocity on top of the suspension layer. The enhancement of turbulence penetration by viscosity is similar to the flow near an oscillating flat plate (Stokes’ second problem), but is opposite to turbulence penetration into a stationary porous and permeable sediment bed. The information is applicable to water quality modeling mear the sediment/water interface of lakes, river impoundments and estuaries.     

Achieving sustainable development goals through participatory forest management: Examples from South-Eastern Bangladesh

Forests managed through peoples' participation can help to achieve a number of sustainable development goals (SDGs). This paper, drawing data from four participatory forest management (PFM) projects in south-eastern Bangladesh, explored: (a) the factors that influenced the outcomes of PFM; and (b) contribution of PFM towards achieving selected SDGs. The research used observation, semi-structured household interviews, group discussions, vegetation survey and Ostromʼs design principles for data collection, Divergent forest conditions and factors in four PFM sites have had differential contribution to SDGs. Heterogeneity of user groups, insufficient coordination, absence of motivation, and land tenure conflicts had affected the attainment of SDGs. The PFM helped to achieve 9–11 SDGs comprising poverty reduction (Goal 1), improving food security (Goal 2), maintaining health and well-being (Goal 3), enhancing childrensʼ education (Goal 4), fair access to jobs and committees (Goals 5 and 10), sources of clean drinking water (Goal 6), affordable energy for cooking (Goal 7), increased household economy (Goal 8), climate change through carbon sequestration (Goal 13), forest conservation (Goal 15), and partnerships with relevant institutions (Goal 16). In order to achieve SDGs, PFM could be viewed as an integral part of government development strategies, which needs sectoral coordination and integration of relevant policies.     

Distribution of PCDDs, PCDFs and dioxin-like PCBs in the blood, testis and adipose tissue of suckling beef calves

To determine the distribution of persistent organochlorine compounds in beef cattle, concentrations of 2,3,7,8-substituted PCDDs, PCDFs and dioxin-like PCBs were measured in the blood, testes and adipose tissue of four two-month-old Japanese Black calves. Of 29 congeners analyzed, 19, 20 and 28 were detected in the blood, testes and adipose tissue, respectively, of three or all calves. Total toxic equivalents (TEQs) were similar in the testes and adipose tissue, and approximately two times higher than in the blood on a lipid weight basis (P<0.05). More PCDDs and PCDFs had accumulated in the testes than in adipose tissue (P<0.01), but more dioxin-like PCBs were found in adipose tissue than in the testes (P<0.0001). Accumulation patterns in the testes and adipose tissue varied among the congeners of PCDD and PCDF, whereas the patterns were similar in dioxin-like PCBs. In particular, highly substituted PCDD congeners were detected at high concentrations in the testes but at lower concentrations in adipose tissue compared with other congeners. By contrast, accumulation levels of highly substituted PCDFs were lower in both those tissues than the other congeners. In conclusion, it was demonstrated that PCDDs, PCDFs and dioxin-like PCBs leave the circulation and accumulate in the testes and adipose tissue in bovine calves. It was suggested that congeners of PCDD, especially highly substituted PCDDs, and PCDFs have a tendency to accumulate in the testis and dioxin-like PCB congeners accumulate readily in adipose tissue.     

Zooplankton fisheries of the world: A review

About 20 species of zooplankters (copepods, mysids, euphausiids, sergestids, and Scyphomedusae) are commercially fished and utilised as food or feed today. The annual world catch of crustacean zooplankton is probably a little less than 210,000 tons and accounts for 11% of the total crustacean catch in the world. The present status of plankton harvesting in various parts of the world is described. Problems in development of plankton fisheries are discussed.     

Material properties of water-swelling material used as a water cutoff treatment material at waste landfill sites

Water-swelling material (WSM) is a fluid sealant obtained by blending high-absorbency polymer, a filler, and a solvent by using a synthetic resin elastomer as the base material. In this research, we studied experimentally the composition of WSM, the extent of swelling, the strength of the WSM and the long-term performance of the swelling material used as a jointed water cutoff treatment material at waste landfill sites. One of the results was that adjusting the degree of etherification of the high-absorbency polymer, which is a component of the WSM, and the resin content of the synthetic elastomer contributed to improvement of the swelling of the sealant and the strength of the swelling material. Further, in long-term tests, the strength of the WSM tended to become stabilized and it was confirmed that it had sufficient pressure resistance for use in coastal landfill sites, where its application as a water cutoff treatment material is being considered.     

Individual variation in pheromone emission and termination patterns in female Anomala cuprea

Summary. Individual variations in pheromone emission patterns were examined in a scarab beetle, Anomala cuprea Hope (Coleoptera: Scarabaeidae), by headspace collection of airborne volatiles from individual females. The amount of pheromone obtained varied among virgin females, and about 16% of these females (“silent” females) did not emit detectable amount of pheromone throughout the experimental period. There was no clear temporal pattern of peak pheromone emission for 19 days after the onset. More than half of the laboratory mated females completely stopped releasing pheromone after the first mating, while the rest of them continued releasing pheromone, frequently followed by additional mating. Received 26 March 2001; accepted 28 January 2002.     

Decolorization of oxygen-delignified bleaching effluent and biobleaching of oxygen-delignified kraft pulp by non-white-rot fungus Geotrichum candidum Dec 1

Decolorization of oxygen-delignified bleaching effluent (abbreviated as OBE) and biobleaching of oxygen-delignified kraft pulp (OKP) were conducted using a non-white rot fungus Geotrichum candidum Dec 1 (abbreviated as Dec 1) which has ability to decolorize various synthetic dyes and molasses. Dec 1 decolorized up to 77% of OBE for 6 days. In addition, Dec 1 increased the brightness of OKP from 47.8% to 51.2% and decreased the kappa value of OKP from 12.4 to 10.4 points during a 6-day incubation period at a 25% of pulpconcentration. At 2% pulp-concentration, the brightness of OKP increased by 13% and the kappa value of OKP decreased by 4 points only for a 3-day incubation period. When the decolorized OBE was used for bleaching of OKP, the brightness of OKP increased to 62.7% under the shaking culture to a 2% pulp-concentration using culture fluid of decolorized OBE. It was revealed that Dec 1 is a potential to apply for decolorization of wastewater and biobleaching of pulp in paper-mills.     

Neonatal outcomes of congenital diaphragmatic hernia in full term versus early term deliveries: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to review the optimal timing of delivery at term for neonates with prenatally diagnosed congenital diaphragmatic hernia (CDH). We reviewed the literature up to December 19, 2022 using MEDLINE and the Cochrane Library databases. The inclusion criteria were original articles, comparative studies of CDH neonates delivered at an early term (37–38 weeks of gestation) and at full term (39 weeks of gestation or later), and comparative studies investigating outcomes of CDH neonates. Six studies met the inclusion criteria, including 985 neonates delivered at an early term and 629 delivered at full term. The cumulative rate of survival to discharge showed no significant difference between CDH neonates delivered at an early term (395/515; 76.7%) or at full term (345/467; 73.9%) (risk ratio [RR] 1.01; 95% confidence interval [CI], 0.89–1.16; p = 0.85). Furthermore, the number of neonates requiring oxygen therapy at discharge was not significantly different between CDH neonates delivered at an early term (32/370; 8.6%) and at full term (14/154; 9.1%) (RR, 0.99; 95% CI, 0.36–2.70; p = 0.99). Therefore, the optimal timing of delivery at term for neonates with CDH remains unclear.     

Effects of Nitrogen Supply on the Sensitivity to O3 of Growth and Photosynthesis of Japanese Beech (Fagus crenata) Seedlings

To obtain basic information for evaluating critical levels of O₃ under different nitrogen loads for protecting Japanese beech forests, two-year-old seedlings of Fagus crenata Blume were grown in potted andisol supplied with N as NH₄NO₃ solution at 0, 20 or 50 kg ha⁻¹ year⁻¹ and exposed to charcoal-filtered air or O₃ at 1.0, 1.5 and 2.0 times the ambient concentration from 16 April to 22 September 2004. The O₃ induced significant reductions in the whole-plant dry mass, net photosynthetic rate at 380 μmol mol⁻¹ CO₂ (A ₃₈₀), carboxylation efficiency (CE) and concentrations of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and total soluble protein (TSP) in the leaves. The concentrations of Rubisco and TSP were negatively correlated with the concentration of leaf acidic amino acid, suggesting that O₃ enhanced the degradation of protein such as Rubisco. The N supply to the soil did not significantly change the whole-plant dry mass and A ₃₈₀, whereas it significantly increased the CE and concentrations of Rubisco and total amino acid. No significant interactive effects of O₃ and N supply to the soil were detected on the growth, photosynthetic parameters and concentrations of protein and amino acid in the leaves. In conclusion, N supply to the soil at ≤50 kg ha⁻¹ year⁻¹ does not significantly change the sensitivity to O₃ of growth and net photosynthesis of Fagus crenata seedlings.