Persistent Organic Pollutants in Singapore's Coastal Marine Environment: Part II,Sediments

Polycyclic aromatic hydrocarbons (PAHs) can enter the marine environment from a variety of anthropogenic sources. As some PAHs are known or suspected carcinogens and mutagens, their potential hazard to human health and the natural environment warrants investigation. This is the first reported study on the prevalence and concentration of PAHs in marine sediments from Singapore's coastal environment, and accompanies the report by Basheer et al. (2003) on the measurement of persistent organic pollutants (POPs) in seawater. The concentration of 16 PAH, classified as USEPA priority pollutants were analysed in sediments from 22 sample stations located within the northeastern and southwestern regions of Singapore's marine waters. The total PAH concentration varied between 15.22 μg g^-1 and 82.41 μg g^-1 in the northeastern region and between 13.63 μg g^-1 and 84.92 μg g^-1in the southwestern region. The highest concentration of total PAH i.e. 84.92 μg g^-1 was recorded at a site adjacent to a petrochemical refinery. Among the sixteen individual PAHs, chrysene, indeno[1,2,3-cd]pyrene and benzo[a]anthracene were most prevalent in the sediments. The relatively low kinetic/thermodynamic isomer ratios for PAHs suggest that PAHs of pyrogenic origin are predominant in Singapore's coastal environment. The distribution of higher molecular weight i.e. (4–5 ring) individual PAHs corresponded to mixture profiles typical of those originating from high temperature combustion processes subjected to photolytic degradation during long-range atmospheric transportation. A comparison of total PAH concentration data for sediments collected from Singapore relative to those reported for other countries indicates a moderate level of PAH contamination in Singapore's coastal marine sediments.     

A survey of entomopathogenic nematodes of the families Steinernematidae and Heterorhabditidae (Nematoda: Rhabditida) in Damascus countryside of Syria

A survey of entomopathogenic nematodes was conducted in Damascus countryside from January 2011 to December 2013. Soil samples were tested for the presence of steinernematid and heterorhabditid nematodes by baiting with Galleria mellonella larvae. Of the 189 soil samples studied 17 were positive for entomopathogenic nematodes (9%), with 11 of these positive samples (65%) containing Heterorhabditis and 6 (35%) Steinernema isolates. Morphological studies were carried out to characterize eight isolates. The Heterorhabditis isolates collected in Syria were identified as Heterorhabditis zealandica (Poinar, 1990), Heterorhabditis indica (Poinar et al., 1992) and Heterorhabditis bacteriophora (Poinar, 1990). Heterorhabditis zealandica was isolated from 4 sites. Heterorhabditis indica and H. bacteriophora were isolated from two sites each. Entomopathogenic nematodes were mainly found in stone fruit orchards and apple orchards but also in citrus groves, vineyards, and walnut orchards.     

Genome wide association study of grain yield and yield related traits in spring bread wheat (Triticum aestivum L.) under drought and heat conditions in three different locations

Journal of Crop Science and Biotechnology - Abiotic stress, especially drought and heat, affects cereal yields and wheat production worldwide, more particularly in West and South Asia, North...     

Persistent Organic Pollutants in Singapore's Coastal Marine Environment: Part I,Seawater

Persistent organic pollutants (POPs) continue to receive widespread attention as harmful contaminants in the global environment. Increasingly, there have been concerns regarding adverse effects on marine wildlife due to the potential of POPs to induce adverse health effects, including the disruption of endocrine systems. Marine water samples within one kilometer of the coastline of Singapore were analysed to determine prevalent concentrations of a range of persistent organic pollutants (POPs). Samples were collected from 0.5 m and mid-depth (approximately 14 m depth) at twenty-two locations. POPs analysed are classed as USEPA priority pollutants, and included: sixteen polycyclic aromatic hydrocarbons (PAHs); eight polychlorinated biphenyls (PCBs); and twelve organochlorine pesticides (OCPs). Total PAH concentrations varied from 88.44 to 1419.57 ng l^-1 at the surface, and 129.78 to 940.41 ng l^-1 at mid-depth. Total OCP concentrations varied between 4.90 ng l^-1 to 22.04 ng l^-1 at surface, and 4.09 to 18.05 ng l^-1 at mid-depth. Total PCB concentrations varied from 0.22 ng l^-1 to 20.41 ng l^-1 at surface and 0.4 to 10.79 ng l^-1 at mid-depth. In general, the distribution profile shows that the surface concentrations of POPs are higher than at mid depth. Concentrations of PAHs were considered higher than reported levels for several other countries, whereas levels of OCPs and PCBs are generally lower than reported levels for other Asian countries.     

Parasitoids on codling moth Cydia pomonella (Lepidoptera: Tortricidae) in apple and walnut orchards in Syria

A survey was performed between 2007 and 2013 to investigate the complex of parasitoids on Cydia pomonella (codling moth) in apple and walnut orchards in Syria. This study showed the presence of 17 species belonging to 7 families from two orders (Hymenoptera and Diptera). The families Ichneumonidae and Braconidae were most common, comprising 8 and 4 species, respectively. Mastrus ridibundus and Neoplectops pomonella were new records for Syria.     

Parasitoids belonging to the genus Aphytis Howard (Hymenoptera: Aphelinidae) in Citrus orchards in Lattakia,Syria

A survey of the common Aphytis spp. Howard (Hymenoptera: Aphelinidae) parasitoids was carried out at four citrus orchards (which were not treated with chemical pesticides) in AL‐Hanade, Stamo, Tarjano and Hmaiem in Lattakia Governorate from September 2010 to September 2011. Six parasitoid species of the genus Aphytis were reared from living armoured scale insects isolated in four states. They were Aphytis lepidosaphes (Compere), Aphytis lingnanesis (Compere), Aphytis chrysomphali (Mercet), Aphytis melinus (DeBach), Aphytis maculicornis (Masi) and Aphytis hispanicus (Mercet).     

Primary and secondary Hymenopteran parasitoids of scale insects (Homoptera: Coccoidea) in fruit orchards in Syria

A survey for primary and secondary Hymenopteran parasitoids of scale insects (Homoptera: Coccoidea) in fruit orchards (apple, plum, date, olive, fig, citrus), was conducted in Syria during 2009–2012. Thirty three species of parasitoids belonging to the families Aphelinidae, Encyrtidae, Eulophidae and Pteromalidae were recorded as parasitoids on scale insects. Thirty two of these were primary parasitoids and one was a hyperparasitoid. The family with the greatest number of genera and species is Encyrtidae with 8 genera (48% of the total) and 12 species (35% of the total). The genus with the greatest number of Encyrtid species was Metaphycus. Parasitoids of scale insects identified included several species already included on the List of biological control agents widely used in the EPPO region ‘EPPO Positive list' and suggestions for additions to this list were made.     

Scale insect species (Hemiptera: Coccoidea) in Syria

Scale insects in Syria were surveyed between 2009 and 2015. This study showed that Diaspididae and Coccidae were the most common families, comprising 5 and 8 species, respectively. The remaining families found comprised 1 species each. New records of Coccoidea fauna from Syria were Parlatoria blanchardi, Phoenicococcus marlatti, Coccus hesperidum, Coccus pseudomagnoliarum and Chionaspis etrusca.     

The influence of bearing cycles on olive oil quality response to irrigation

Five rates of water application were applied in a 4 year study on olive (Olea europaea) varieties 'Barnea' and 'Souri'. Increased irrigation lead to increased tree-scale oil yields, lower polyphenol content, and, frequently, higher oil acidity. These effects were predominant in "off" years. The fatty acid profile was influenced primarily by bearing level and variety and secondarily by irrigation rate. The saturated to unsaturated fatty acid ratio was higher in "off" than in "on" years, and the monounsaturated fatty acid to polyunsaturated fatty acid ratio was higher in "on" years as a result of the fact that oleic and stearic acids were higher in "on" years, while palmitic, palmitoleic, and linoleic acids were greater in "off" years. Squalene was higher in 'Souri' than in 'Barnea' oils, was not affected by bearing cycle, and was consistently lower in oil from trees receiving the lowest irrigation level.     

Development and characterization of a fibroblastic‐like cell line from caudal fin of the red‐line torpedo,Puntius denisonii (Day) (Teleostei: Cyprinidae)

A fibroblastic‐like cell line was established from the ornamental fish, red‐line torpedo (Puntius denisonii). The red‐line torpedo fin (RTF) cell line is being maintained in Leibovitz's L‐15 medium supplemented with 10% fetal bovine serum (FBS) for over 1 year at 28 °C on a continuous basis in normal atmosphere. The growth rate of RTF cells increased as the FBS proportion increased from 5% to 20% at 28 °C with optimum growth at the concentrations of 10% FBS. The morphology of RTF cell was predominantly fibroblastic like. Propagation of these cell lines was serum dependent, with a low plating efficiency (<15%). Karyotyping analysis of RTF cells at the 25th passage indicated that the modal chromosome number was 2n=50. The cell line was cryopreserved in liquid nitrogen at ?196 °C and could be recovered from storage after 6 months with good cell viability. Polymerase chain reaction amplification of a fragment of two mitochondrial genes, 16S rRNA and CO1, confirmed the identity of these cell lines with those reported from this animal species, confirming that the cell lines originated from P. denisonii. The bacterial extracellular products from Vibrio cholerae MTCC3904 and Aeromonas hydrophila were found to be toxic to RTF. The cell lines were not susceptible to viral nervous necrosis virus, a marine fish virus.