A comparison of flux chambers and ambient air sampling to measure gamma-hexachlorocyclohexane volatilisation from canola (Brassica napus) fields

The insecticide gamma-hexachlorocyclohexane (gamma-HCH) is primarily used in Canada in treatments of canola (Brassica napus) seed. It has been shown that gamma-HCH so applied will volatilise with 12-30% entering the atmosphere within 6 wk after the seed is planted. Both flux chambers and high-volume air samplers were used to measure gamma-HCH volatilisation from a canola field and the results from each method compared. Daily samples were collected from three flux chambers located on the field. gamma-HCH was found in the air of the chambers on the first day after planting. Volatilisation rates were low for the first 7d (40.0 mg ha(-1) wk(-1)) but increased during the second week (143.8 mg ha(-1) wk(-1)). This was consistent with previous studies. Weekly composite air samples, from three heights above the canola field, were used to calculate volatilisation rates from the field. These were 190 mg ha(-1) wk(-1) (week 1) and 420 mg ha(-1) wk(-1) (week 2). Soil temperatures in the open field were warmer than those under the flux chambers and this may have contributed to the higher ambient air measurements.     

Prenatal diagnosis of Pierre–Robin sequence as part of Stickler syndrome

Stickler syndrome or hereditary progressive arthro-ophthalmopathy, is an autosomal dominant condition characterized by ocular manifestations, arthritic changes, orofacial features and deafness, in variable degrees. We report the first case of prenatal diagnosis of Stickler syndrome in a child with a Pierre–Robin sequence (PRS) causing a polyhydramnios. When isolated polyhydramnios is not explained by immunological, metabolic or infectious causes, swallowing difficulty due to PRS must be considered. As PRS is aetiologically heterogenous, the prognosis depends on the cause. Genetic investigations and familial history must be taken into account. Here, in a context of familial Stickler syndrome, making the prenatal diagnosis of PRS as part of Stickler syndrome allowed us to reassure the parents and to anticipate airway trouble at the child's birth. Copyright © 2002 John Wiley & Sons, Ltd.     

A predictive study of emotional labor and turnover

The current study examined how the emotional labor strategies of deep acting and surface acting directly influence emotional exhaustion and turnover intentions, and indirectly impact actual turnover among a sample of bank tellers. Turnover data were collected from organizational records 6 months after participants responded to a survey that measured emotional labor strategies, emotional exhaustion, and turnover intentions. Results showed that turnover intentions mediated the relationship between deep acting and actual turnover. Additionally, surface acting had indirect effects on turnover through emotional exhaustion and turnover intentions. Copyright © 2009 John Wiley & Sons, Ltd.     

Environmental impacts of building materials and building services components for commercial buildings in Hong Kong

The growing concerns over the environmental impacts of buildings have led to increasing demands for more environmental friendly buildings and building materials. Hitherto, there are not any comprehensive studies that show the overall environmental impact profiles of building materials and building services components for buildings. This paper intends to bridge this gap by reporting overall lifecycle environmental profiles of buildings as well as the ranking orders of environmental impacts of all the building materials and building services materials and components for commercial buildings. Twenty-five commercial buildings in Hong Kong, which include three Grade A office buildings, four Grade B office buildings, one Grade C office buildings, four retail centers and three hotels, have been selected for our study. Based upon these collected samples, no statistical differences were found in the average lifecycle environmental impacts for different building types despite some minor variations were detected. Subsequently, 10 types of building materials and 10 types of building services components have been identified for their significant lifecycle environmental impacts on commercial buildings. Among all, concrete, reinforcement bar, copper power cables, and copper busbars were ranked to be the four most significant materials or components to the total lifecycle environmental impacts. These should form the major targets for improvements in environmental performance of commercial buildings.     

Plant extract-mediated synthesis of aluminum oxide nanoparticles for water treatment and biomedical applications: a review

Environmental Chemistry Letters - Nanotechnologies have contributed to disease control and prevention, but conventional synthesis of nanoparticles rarely meets the strict requirements of green...     

Electrochemical treatment of domestic wastewater using boron-doped diamond and nanostructured amorphous carbon electrodes

The performance of the electrochemical oxidation process for efficient treatment of domestic wastewater loaded with organic matter was studied. The process was firstly evaluated in terms of its capability of producing an oxidant agent (H₂O₂) using amorphous carbon (or carbon felt) as cathode, whereas Ti/BDD electrode was used as anode. Relatively high concentrations of H₂O₂ (0.064 mM) was produced after 90 min of electrolysis time, at 4.0 A of current intensity and using amorphous carbon at the cathode. Factorial design and central composite design methodologies were successively used to define the optimal operating conditions to reach maximum removal of chemical oxygen demand (COD) and color. Current intensity and electrolysis time were found to influence the removal of COD and color. The contribution of current intensity on the removal of COD and color was around 59.1 and 58.8 %, respectively, whereas the contribution of treatment time on the removal of COD and color was around 23.2 and 22.9 %, respectively. The electrochemical treatment applied under 3.0 A of current intensity, during 120 min of electrolysis time and using Ti/BDD as anode, was found to be the optimal operating condition in terms of cost/effectiveness. Under these optimal conditions, the average removal rates of COD and color were 78.9?±?2 and 85.5?±?2 %, whereas 70 % of total organic carbon removal was achieved.     

Impact of hydroxylated and non-hydroxylated aliphatic glucosinolates in Arabidopsis thaliana crosses on plant resistance against a generalist and a specialist herbivore

Glucosinolates (GSs) are part of a two-component defence system, characteristic for the Brassicales, including the model species Arabidopsis thaliana (L.) Heynh. The defence activity of GSs is associated with different side chain structures. The AOP genes are central in side-chain modification. AOP2 mediates formation of alkenyl GS from a methylsulfinyl precursor, whereas AOP3 catalyzes production of hydroxy-alkyl GSs from the same precursor. Although several studies have assessed the role of GSs in plant defence, the function of specific aliphatic GSs in plant defence is still not clarified. Structural different GSs may influence insect herbivores differentially. We created a set of plant lines derived of a cross between two A. thaliana accessions, Gie-0 × Sap-0, which dominantly accumulate either 3-methylsulfinylpropyl GS or 3-hydroxypropyl GS. The generalist Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) and the crucifer-specialist Pieris brassicae (L.) (Lepidoptera: Pieridae) were used as model insects, to study effects of individual aliphatic GSs on lepidopteran herbivores with a different feeding specialization. However, the experiments revealed that weight gain of S. exigua and P. brassicae third and fourth-larval instars was similar on both chemotypes. But leaf consumption of the generalist was higher on 3-methylsulfinylpropyl-producing lines with low GS levels (23.2 μmol g⁻¹) than on 3-hydroxypropyl-producing lines that contained a more than twofold higher amount of GSs (60 μmol g⁻¹). In contrast, no differential effects of non-hydroxylated and hydroxylated GSs were found on the specialist P. brassicae. Our study indicates that there is no simple relationship between GS content and insect responses.     

Community exposure to arsenic in the Mekong river delta, Southern Vietnam

We examined the daily inorganic arsenic (i-As) intake from drinking water and rice in 45 households (75 individuals) in the An Giang province, Southern Vietnam. The daily i-As intake ranged from 28-102 μg d(-1), equivalent to the daily dose of 0.6-1.9 μg d(-1) kg((body wt))(-1). Increased As concentrations were observed in human hair in the study location. Approximately 67% (n = 44), 42% (n = 28), and 15% (n = 10) of the hair samples had As levels exceeding 1, 3, and 10 μg g(-1), respectively. The total As concentrations in female and male hair correlated well with the total daily i-As intake. Measurement of As concentrations in the hair of people who were consuming or had previously consumed As from contaminated sources may help predict the onset of negative health effects. We suggested an application of the Bayes's theorem to calculate the probability that an individual in a population will acquire a negative health effect, given that the concentration of arsenic in the subject's hair has been determined.     

Application of WRF-Chem to simulate air quality over Northern Vietnam

Environmental Science and Pollution Research - The WRF-Chem (Weather Research and Forecasting with Chemistry) model is implemented and validated against ground-based observations for meteorological...