Effects of bacteria on metal bioavailability,speciation, and mobility in different metal mine soils: a column study

Purpose  

Successful phytoremediation depends mainly on the bioavailability of heavy metals in the soil. Recently, soil microbes possess several mechanisms that are able to change metal bioavailability in the soil, which provides a new strategy for investigating biogeochemical cycling of metals in contaminated soils. Three metal mines soils with elevated concentrations of Cd, Pb, and Zn from China were applied in this column study to (1) evaluate the effects of metal tolerant bacterial inoculation (Burkholderia cepacia, accession number: AB051408) on metal release, (2) monitor the migration of metals in the rhizospheric horizon (0–20 cm), and (3) investigate metal speciation and sequential fractions in soil.     

Structures,dynamics and stability of reef fish assemblages in non‐reefal coral communities in Hong Kong,China

• 1. A detailed study on the spatial and temporal patterns of reef fish assemblages associated with non‐reefal coral communities at A Ma Wan (AMW) and A Ye Wan (AYW) in Tung Ping Chau, Hong Kong, China, was carried out using an underwater visual census method from January 1998 to December 1999.
• 2. The study identified a total of 106 species (76 genera in 39 families) of fish in the study sites, in which 88 species were recorded in AMW and 78 species in AYW. Seasonal patterns in the abundance and species richness of all reef fishes and most of the frequently encountered families/trophic groups in both study sites were observed. Seasonal fluctuation of macroalgae, the influence of recruitment of larvae, and the possible seasonal variation in the behaviour of fish may all contribute to these observed seasonal patterns.
• 3. Multidimensional scaling (MDS) ordinations demonstrated that there were spatial variations in the fish community structures within and between sites. Such spatial patterns were possibly related to the spatial variation of the coral community structures in the study sites. The ordinations also showed that the fish community structures in the study sites were not seasonally stable. Such temporal instability of the fish community structures may be partly due to habitat isolation among the fish communities around the island.
• 4. These results imply that preservation and enhancement of habitat connectivity of the coral communities should be one of the main conservation strategies for the reef fish communities of Tung Ping Chau, and those of Hong Kong in general. This strategy may be equally applicable to other non‐reefal coral communities elsewhere around the world.

Copyright © 2008 John Wiley & Sons, Ltd.     

Place,identity and immigrant communities: The organisation of the Yulan Festival in post‐war Hong Kong

Abstract: In the process of migration, some traditions persist while others do not. The Yulan Festival, also known as the Ghost Festival, continues to be observed by different subethnic Chinese migrant groups in Hong Kong for a variety of reasons. Although the festival organisation accentuates subethnic distinctions, paradoxically it also enables different groups to integrate into the larger community. The activities articulate various meanings of ‘place’– as ‘ancestral place’ on the mainland where
the rituals are believed to originate, as the specific locality/neighbourhood in Hong Kong where the festival is held, and Hong Kong as a whole. This article, based on interviews with Chiu Chow and Hoklo participants, shows how they think of the different meanings of ‘place’, which in turn reflects the way they make sense of the process of migration.     

Ecological Performance of the Restored South East New Territories (SENT) Landfill in Hong Kong (2000–2012)

South East New Territories (SENT) landfill (Phase I) was saturated with wastes and capped with a cover system to prevent rainfall infiltration and gas emission and to support plant growth. Subsequently, a revegetation program was conducted in 1997. Line transects were used for monitoring (i) the restored area (AT), (ii) the area adjacent to AT (BT) and (iii) the area outside AT, which served as control (CT). Flora and fauna diversities, plant performance (chlorophyll florescent and stomatal resistance of Acacia confusa) and soil properties were monitored during 2000–2012. There were 28, 24 and 23 plant species, and 61, 39 and 61 animal species found at AT, BT and CT during the past 13 years, respectively. The total number of plants recorded at AT fluctuated considerably, and was more stable at BT, especially CT. The results of similarity analyses showed that the plant community at AT were significantly different (P < 0·01) from those at BT and CT, whereas no difference was noted among fauna communities at different sites. Soil properties, including pH, bulk density, moisture content, total organic content, organic matter, total Fe and total Zn were significantly different (P < 0·05) among sites. The decreasing trend of soil pH in all sites indicated that regional soil acidification may have occurred. Soil moisture content and stomatal resistance of A. confusa were negatively correlated, which showed that AT was more subjected to drought than BT and CT. Plants in restored area were more sensitive to the changes in environmental conditions compared with those of control site. Copyright © 2015 John Wiley & Sons, Ltd.     

Root Morphology and Anatomy Affect Cadmium Translocation and Accumulation in Rice

Paddy fields contaminated with cadmium (Cd) present decreased grain yield and produce Cd-contaminated grains. Screening for low-Cd-accumulating cultivars is a useful method to reduce the amount of Cd in the grains. The present study aimed to examine the roles of the root morphology and anatomy in Cd translocation and accumulation in rice plants. Twenty-two rice cultivars were used in the first experiment, after which two cultivars [Zixiangnuo (ZXN) and Jinyou T36 (JYT36)] were selected and used in subsequent experiments under hydroponic conditions. The results showed that there were significant differences in Cd concentrations in the shoots (ranging from 4 to 100 mg/kg) and the Cd translocation rates (shoot/root) (from 7% to 102%) among the 22 cultivars, and the shoot Cd concentration was significantly correlated with the Cd translocation rate of the 22 cultivars under 0.1 mg/L Cd treatment. Compared with cultivar ZXN, JYT36 had greater root Cd uptake and accumulation but lower shoot Cd accumulation and Cd translocation rate. The number of root tips per surface area of cultivar ZXN was greater than that of JYT36, while the average root diameter was lower than that of JYT36. Compared with ZXN, JYT36 had stronger apoplastic barriers, and the Casparian bands and suberin lamellae in the root endodermis and exodermis were closer to the root apex in both the control and Cd treatments, especially for suberin lamellae in the root exodermis with Cd treatments, with a difference of 25 mm. The results also showed that, compared with ZXN, JYT36 had greater percentages of Cd bound in cell walls and intracellular Cd but lower Cd concentrations in the apoplastic fluid under the Cd treatment. The results suggested that Cd translocation, rather than root Cd uptake, is a key process that determines Cd accumulation in the rice shoots. The root morphological and anatomical characteristics evidently affect Cd accumulation in the shoots by inhibiting Cd translocation, especially via the apoplastic pathway. It was possible to pre-screen low-Cd-accumulating rice cultivars on the basis of their root morphology, anatomical characteristics and Cd translocation rate at the seedling stage.     

Comparative analysis of caffeoylquinic acids and lignans in roots and seeds among various burdock (Arctium lappa) genotypes with high antioxidant activity

Caffeoylquinic acids and lignans in the crude extracts of both roots and seeds from different burdock ( Arctium lappa L.) genotypes were simultaneously characterized and systematically compared by LC-MS and matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (MALDI-QIT-TOF MS), and their antioxidant activities were also investigated. A total of 14 lignans were identified in burdock seeds and 12 caffeoylquinic acids in burdock roots. High levels of caffeoylquinic acids were also detected in burdock seeds, but only trace amounts of lignans were found in burdock roots. Burdock seeds contained higher concentrations of lignans and caffeoylquinic acids than burdock roots. Quantitative analysis of caffeoylquinic acids and lignans in roots and seeds of various burdock genotypes was reported for the first time. Great variations in contents of both individual and total phenolic compounds as well as antioxidant activities were found among different genotypes. Burdock as a root vegetable or medicinal plants possessed considerably stronger antioxidant activity than common vegetables and fruits.     

Hull split and damaged almond volatiles attract male and female navel orangeworm moths

A blend of volatiles derived from the emissions of almonds at hull split and mechanically damaged almonds was compared to almond meal, the current monitoring standard for the insect pest navel orangeworm (NOW). Field trapping studies were performed to determine the blend's ability to attract adult NOW. The blend comprised racemic 1-octen-3-ol, ethyl benzoate, methyl salicylate, acetophenone, and racemic (E)-conophthorin. Ethyl acetate was used as a solvent with a blend component concentration of 100 mg/mL. The blend attracted both sexes of NOW when tested in five 2-week intervals spanning the first three flights of NOW in commercial almond orchards in the southern Central Valley of California. The blend demonstrated consistently higher capture rates for female NOW throughout the evaluation period, but unlike almond meal it significantly attracted males. Reported is a survey of the major and minor volatiles emitted from almonds at hull split, the key period of vulnerability to NOW infestation. Also reported is the attractancy of a formulated test blend based on the host plant volatile emissions, electroantennographic screening experiments, and field trapping studies. The results of this test blend highlight progress toward a host-plant-based attractant for NOW, a major insect pest of California tree nuts that presently lacks an adequate monitoring tool.     

From followers to market leaders: Asian electronics firms in the global economy

Abstract: This paper aims to explain how a number of leading electronics firms from Asian newly industrialised economies of Hong Kong, Singapore, South Korea and Taiwan are articulated into global production networks and become major players in their respective market niches. Developing a triangular theoretical framework, I seek to explain the complex relationships between the dynamic articulation of these leading Asian electronics firms into different global production networks and their simultaneous upgrading from typical followers to market leaders. As a critique of the dominant developmental state discourse, I argue that the interplay between corporate strategies and home base advantages within the context of changing global production networks can offer a better explanation of the differentiated competitive outcomes of these Asian firms. This paper draws upon original data collected through personal interviews with top executives from leading electronics firms in the four Asian newly industrialised economies. I conclude the paper with some implications for theory and policy in relation to corporate development in Asian economies.