Hybridization of the natural antibiotic, cinnamic acid, with layered double hydroxides (LDH) as green pesticide

Background, aim, and scope  

Heavy application of highly toxic synthetic pesticides has been committed to protect crops against insects and diseases, which have brought about serious environmental problems. Thus, an inevitable and fundamental issue has been how to protect crops without harmful effects on nature. As a fascinating nature-compatible approach, we have attempted to hybridize soil-compatible layered double hydroxides (LDHs) with natural antibiotic substances. Only a few of natural antibiotic substances are available for pest control mainly because of their inherent properties such as easy degradability, high minimum inhibition concentration for practical application, and often extremely low availability, whereas LDHs exhibit unique properties such as anion exchange capacity, acid lability, and high affinity to ubiquitous carbonate ion which make them an excellent inorganic matrix to carry labile biomolecules in soils. This study focuses on the behavior of cinnamate–LDH hybrid in soils and the evaluation of its potentials as a green pesticide.     

Development of freshwater sediment management standards for organic matters, nutrients, and metals in Korea

Korean water quality managers are required to promptly develop national assessment standards for freshwater sediment quality due to the Four Major River Restoration Project in Korea in 2009. We conducted this study to develop sediment management standards (SMSs), determining obviously and severely polluted sediment, which could have adverse impacts on water quality and aquatic ecosystem. The SMSs values were derived from the 95th percentile of concentration distribution for organic matter and nutrients in sediment quality database. For the SMSs of metals, foreign sediment quality guidelines (SQGs) were adopted. As a result, 13 % for loss on ignition (LOI), 1,600 mg/kg for total phosphorus (TP), and 5,600 mg/kg for total nitrogen (TN) were set as the SMSs for freshwater sediment in Korea. These values were higher than the range of heavily polluted sediment from USEPA Region 5 guideline derived by the similar approaches for the Great Lakes harbor sediments, and similar or lower than the severe effect level (SEL) from provincial sediment quality guideline (PSQG) of Ontario, Canada by screening level concentration (SLC) approach. However, SMSs in the present study are appropriate considering the concentration ranges and the Korean SMSs’ definition for freshwater sediments in Korea. The Puget Sound marine sediment cleanup screening level (CSL) in Washington State, USA were adopted as the Korean SMSs for As (93 mg/kg), Cd (6.7 mg/kg), Cr (270 mg/kg), Cu (390 mg/kg), Pb (530 mg/kg), and Zn (960 mg/kg) in freshwater sediments. Hg concentration (0.59 mg/kg) of CSL was too low to determine the polluted freshwater sediments in Korea, and the SEL of Ontario, Canada for mercury concentration (2 mg/kg) was selected as the SMS for Hg. These values were found reasonable through the assessment of applicability with the datasets from locations directly affected by obvious point sources. These results indicate that SMSs for organic matter, nutrient, and metals derived within the present study can successfully determine obviously and severely polluted sediment in Korea. However, the SMSs have limits to specifically determine the effects of polluted sediment on water quality and aquatic ecosystem in Korea. Thus, we will revise and specify SMSs considering those effects and further sediment quality assessment framework in the near future.     

Simple ultrasonic diagnosis of osteogenesis imperfecta type II in early second trimester

Osteogenesis imperfecta (OI) Type II was diagnosed accurately in an at-risk fetus at 16 weeks gestation by real-time sonography. The most important findings were shortening, deformity and possibly fracture in the long bones particularly the femurs. Ultrasonic visualization of these signs in a fetus at risk will provide direct evidence in the diagnosis of OI Type II and any additional investigations are not indicated.     

Preface Coping with hydrological extremes

Mitigation and Adaptation Strategies for Global Change -     

Cadmium ion sorption onto lignocellulosic biosorbent modified by sulfonation: the origin of sorption capacity improvement

Juniper (Juniperus monosperma), a small-diameter underutilized material, has been studied as a lignocellulosic biosorbent for removing heavy metals from water. In this study, juniper wood was modified by sulfonation to enhance sorption capacity for cadmium in water. The origin of the enhancement was investigated by observing the sorption behaviors and the change in surface functional group concentrations. Cadmium sorption by all juniper wood biosorbents studied was fast and the sorption capacity decreased with decreasing pH, similar to results found for other biosorbents. Sulfonated juniper was found to have at least twice the sorption capacity for cadmium removal from water compared to that of untreated juniper, though the sorption capacity increased with increasing pH. A slight increase in carboxylate content after sulfonation was likely responsible for a small portion of the enhancement. Elemental analysis showed an increase in sulfur content after sulfonation. Diffuse reflectance infrared Fourier transform (DRIFT) spectra showed a decrease in the band at 1660 cm(-1) in the range of carbonyl groups as a result of sulfonation. This indicates that coniferaldehyde groups in the lignin of juniper wood corresponding to this band were substituted into sulfonic acid groups after sulfonation. This interpretation was supported by both the color forming reaction with phloroglucinol-hydrochloric acid and the reaction mechanisms from the acid sulfite pulping process. Consequently, the enhancement of cadmium sorption capacity of juniper wood by sulfonation mainly originated from the production of sulfonic acid groups, which are binding sites for heavy metals.     

Studies on the biology of the red sea bream Chrysophrys major III. Metabolic response to starvation in different salinities

Red sea breams were kept at 20°C without food at 3 salinities (full sea water, 950 mOsm kg^-1; 2/3 sea water, 640 mOsm kg^-1; 1/3 sea water, 330 mOsm kg^-1). In fish adapted to all 3 salinities, starvation resulted in marked decline of plasma FFA and -hydroxybutyrate and liver glycogen levels but plasma glucose and lactate concentrations were maintained. These findings suggest that with the onset of starvation, enhanced hepatic glycogenolysis and decreased fat utilization occurred. Fish, adapted to full and 2/3 sea water, could not survive for more than 19 d without food. However, fish adapted to 1/3 sea water could tolerate 27 d of starvation. Enhanced survival during starvation in 1/3 sea water was observed to be associated with maintenance of plasma protein and elevation of hepatic glucose-6-phosphate dehydrogenase activity. It is suggested that sea breams be transferred to an iso-osmotic medium whenever the threat of starvation prevails, but this suggestion has yet to be evaluated in economic terms.Please communicate with Dr. Norman Y. S. Woo     

Ecology of marine fouling organisms at Eastern Johore Strait

Marine biofouling causes problems to marine structure and obstructs condenser tubes in cooling systems which use sea water as the coolant. The main purpose of this study is to investigate the seasonal ecology of biofouling organisms such as the green mussel, Perna viridis, the dominant fouling species in the Eastern Johore Straits at the Senoko Power Station. The spawning time and its relationship with environmental conditions were studied. The physical, chemical and biological conditions of the sea at Senoko were monitored for a year. Settling slides were used to study the fouling succession in different monsoon seasons. The study showed that there were two main spawning peaks for the green mussel and that these peaks occurred during the intermonsoon months of November and April. These peaks were also correlated with the bimodal patterns for salinity, dissolved oxyen, bivalve veliger larval density and total plankton biomass of the Eastern Johore Strait water. Succession patterns were similar during the two monsoon seasons, however, the rate of fouling was probably greater during the southwest monsoon months. It is therefore advisable that the control or reduction of biofouling in Eastern Johore Strait should take into account the seasonal fluctuations and spawning of the fouling organisms.     

Public perception of locally unwanted facilities in Hong Kong: implications for conflict resolution

This paper aims to investigate factors affecting public attitude towards the siting of locally unwanted land uses (LULUs) and to explore the possible strategies to resolve such conflicts. Three questionnaire surveys were undertaken in communities with different siting experiences and socio-economic profiles. Over 750 individuals were successfully interviewed in each study district. The three communities were found to share similar risk beliefs but show variations in the level of awareness of and response to LULUs. In communities with a disproportionate share of LULUs, many residents did not trust the government in handling LULU issues and thought that the siting process was unfair. The results of the binary logistic regression analysis show that people are likely to oppose the siting of a LULU in their community if they have a negative siting experience, do not perceive the need, accord a high risk to the facility and have a low level of trust in government. The resolution strategies preferred by the public are greater public participation and effective mitigation of risks and impacts, rather than provision of compensation and incentives. All these call for policy-makers to be sensitive to local concerns, engage the public in the process, communicate risks effectively and foster trust building.     

Effect of reactive media composition and co-contaminants on sulfur-based autotrophic denitrification

As a part of a study developing a biological reactive barrier system to treat nitrate-contaminated groundwater, the effects of reactive media composition and co-contaminants on sulfur-oxidizing autotrophic denitrification were investigated. The size of sulfur granules affected the denitrification rates; kinetic constants of 2.883, 2.949, and 0.677 mg-N(1/2)/L(1/2)/day were obtained when the granule sizes were below 2 mm, between 2 and 5 mm, and over 5 mm, respectively. When the volume ratios of sulfur to limestone were 1:1, 2:1, 3:1, and 4:1, kinetic constants of 5.490, 3.903, 4.072, and 2.984 mg-N(1/2)/L(1/2)/day were obtained, respectively. The presence of TCE up to 20 mg/L didn't significantly affect nitrate removal efficiency. At the TCE concentration of 80 mg/L, however, nitrate removal was markedly inhibited. Also, Zn and Cu inhibited the denitrification activity at more than 0.5 mg/L of concentration whereas Cr (VI) did not significantly affect the nitrate removal efficiency at all levels tested.     

Evaluation of SWAT sub-daily runoff estimation at small agricultural watershed in Korea

A study was undertaken for the prediction of runoff flow from 0.8 ha field-sized agricultural watershed in South Korea using Soil and Water Assessment Tool (SWAT) sub-daily. The SWAT model with sub-daily configuration predicted flow from the watershed within the range of acceptable accuracy. The SWAT sub-daily simulations were carried out for a total of 18 rainfall events, 9 each for calibration and validation. Overall trend and extent of matching simulated flow for the rainfall events in 2007-2008 with measured data during the calibration process were coefficient of determination (R²) value of 0.88 and Nash and Sutcliffe Efficiency (E_NS) value of 0.88. For validation, R² and E_NS values were 0.9 and 0.84, respectively. Whereas R² and E_NS values for simulation results using daily rainfall data were 0.79 and -0.01, respectively, that were observed to be out of acceptable limits for the model simulation. The importance of higher time resolution (hourly) precipitation records for flow simulation were evaluated by comparing R² and E_NS with 15 min, 2 h, 6 h and 12 h precipitation data, which resulted in lower statistics with increases in time resolution of precipitation data. The SWAT sub-daily sensitivity analysis was performed with the consideration of hydraulic parameter and was found as in the rank order of CN2 (curve number), ESCO (soil evaporation compensation factor), GW_DELAY (ground water delay time), ALPHA_BF ( base flow alpha factor), GWQMN ( a threshold minimum depth of water in the shallow aquifer required for return flow to occur) , REVAPMN (minimum depth of water in shallow aquifer for re-evaporation to occur) , LAT_TIME (lateral flow travel time) respectively. These sensitive parameters were evaluated at 10% higher and lower values of the parameters, corresponding to 70.5% higher and 23.2% lower in simulated flow out from the SWAT model. From the results obtained in this study, hourly precipitation record for SWAT sub-daily with Green-Ampt infiltration method was proven to be efficient for runoff estimation at field sized watershed with higher accuracies that could be efficiently used to develop site-specific Best Management Practices (BMPs) considering rainfall intensity, rather than simply using daily rainfall data.