Concentrations of Heavy Metals (Cu, Cd, Zn and Ni) and PAHs in Perna viridis Collected from Seaport and Non-seaport Waters in the Straits of Johore.
- Bulletin of environmental contamination and toxicology
- Published over 6 years ago
In this study, the ranges of pollutants found in the soft tissues of Perna viridis collected from Kg. Masai and Kg. Sg. Melayu, both located in the Straits of Johore, were 0.85-1.58 μg/g dry weight (dw) for Cd, 5.52-12.2 μg/g dw for Cu, 5.66-8.93 μg/g dw for Ni and 63.4-72.3 μg/g dw for Zn, and 36.4-244 ng/g dry weight for ∑PAHs. Significantly (p < 0.05) higher concentrations of Cd, Cu, Ni, Zn and ∑PAHs in the mussels were found in the water of a seaport site at Kg. Masai than a non-seaport site at Kg. Sg. Melayu population. The ratios of low molecular weight/high molecular weight hydrocarbons (2.94-3.42) and fluoranthene/pyrene (0.43-0.45) in mussels from both sites indicated the origin of the PAHs to be mainly petrogenic. This study has demonstrated the utility of using the soft tissues of P. viridis as a biomonitor of PAH contamination and bioavailability in the coastal waters of Peninsular Malaysia.
- Journal of the American Mosquito Control Association
- Published over 2 years ago
Based on an ethnobotanical study on use for plant species against mosquito bites in the Kota Tinggi District, Johor State, Malaysia, 3 plants selected for study, Citrus aurantifolia (leaves), Citrus grandis (fruit peel), and Alpinia galanga (rhizome), were extracted using hydrodistillation to produce essential oils. These essential oils were then formulated as a lotion using a microencapsulation process and then tested for their repellent effect against Aedes aegypti. N,N-diethyl-m-toluamide (deet) was also prepared in the same formulation and tested for repellency as controls. Four commercial plant-based repellent (KAPS(®), MozAway(®), BioZ Natural(®), and Mosiquard(®)) also were incorporated in the bioassay for comparison purposes. Bioassays revealed that at 20% concentration all repellent formulations demonstrated complete protection for 2 h and >90% for 4 h post-application. The A. galanga-based formulation provided the greatest level of protection (98.91%), which extended for 4 h post-application and was not significantly different from deet at similar concentration. When compared with commercial plant-based repellents (KAPS(®), MozAway(®), and BioZ Natural(®)), the 3 lotion formulations showed significantly better protection against Ae. aegypti bites, providing >90% protection for 4 h. In conclusion, our 3 plant-based lotion formulations provided acceptable levels of protection against host-seeking Ae. aegypti and should be developed.
Fine scale population structure of Malays - the major population in Malaysia, has not been well studied. This may have important implications for both evolutionary and medical studies. Here, we investigated the population sub-structure of Malay involving 431 samples collected from all states from peninsular Malaysia and Singapore. We identified two major clusters of individuals corresponding to the north and south peninsular Malaysia. On an even finer scale, the genetic coordinates of the geographical Malay populations are in correlation with the latitudes (R(2) = 0.3925; P = 0.029). This finding is further supported by the pairwise FST of Malay sub-populations, of which the north and south regions showed the highest differentiation (FST [North-south] = 0.0011). The collective findings therefore suggest that population sub-structure of Malays are more heterogenous than previously expected even within a small geographical region, possibly due to factors like different genetic origins, geographical isolation, could result in spurious association as demonstrated in our analysis. We suggest that cautions should be taken during the stage of study design or interpreting the association signals in disease mapping studies which are expected to be conducted in Malay population in the near future.
Coeliccia erici Laidlaw, 1917 is re-described and illustrated for both sexes; its taxonomic history and the confusion surrounding it is discussed. Coeliccia kimurai Asahina, 1990 is shown to be a junior synonym of C. erici. Coelicca sameerae sp. nov. (holotype ♂, small stream near Sungai Lasir, Tasik Kenyir, Terengganu, Malaysia, deposited in the Natural History Museum, London) is described from both sexes from Peninsular Malaysia; this species had been confused with C. erici until now. A remark on the status of Coeliccia simillima Laidlaw, 1917 is made.
Resting strategies of planktonic organisms are important for the ecological processes of coastal waters and their impacts should be taken into consideration in management of water bodies used by multiple industries. We combined different approaches to evaluate the importance of resting stages in Singapore coastal waters. We used molecular approaches to improve the knowledge on Singapore biodiversity, we sampled and extracted cysts from sediments to evaluate the density of resting stages in Johor Strait, and we compared systematically information on Singapore planktonic biodiversity to existing published information on resting stages from these reported organisms. This is the first study evaluating the importance of resting stages in Singapore waters. Above 120 species reported in Singapore are known to produce resting stages though no previous work has ever been done to evaluate the importance of these strategies in these waters. The results from the resting stage survey confirmed 0.66 to 5.34 cyst g-1 dry weight sediment were present in the Johor Strait suggesting that cysts may be flushed by tidal currents into and out of the strait regularly. This also suggest that the blooms occurring in Singapore are likely due to secondary growth of Harmful Algae Bloom species in the water rather than from direct germination of cysts from sediment. Finally, we discuss the importance of these resting eggs for three main national industries in Singapore (shipping, marine aquaculture and provision of drinking water through seawater desalination). We argue that this study will serve as a baseline for some of the future management of Singapore waters.
Limited information exists regarding juvenile generalized pustular psoriasis (GPP). We aim to determine the clinical profile and outcome of Malaysians with juvenile GPP.
Here, taxonomic notes on species from three genera of bark crickets are presented. A new locality is recorded for Duolandrevus (Bejorama) parvulus Gorochov, 2016: Singapore. Two new species of Landrevinae are described: one species of Endodrelanva Gorochov, 1999 from Singapore: Endodrelanva jimini sp. nov.; one species of Odontogryllodes Chopard, 1969 from Fraser’s Hill, Peninsular Malaysia: Odontogryllodes gratus sp. nov. The male of Odontogryllodes latus Chopard, 1969 is also described for the first time and female is redescribed. Keys to all known species of Endodrelanva and Odontogryllodes is provided.
In this dataset, we distinguish 15 accessions of Garcinia mangostana from Peninsular Malaysia using Fourier transform-infrared spectroscopy coupled with chemometric analysis. We found that the position and intensity of characteristic peaks at 3600-3100 cm(-) (1) in IR spectra allowed discrimination of G. mangostana from different locations. Further principal component analysis (PCA) of all the accessions suggests the two main clusters were formed: samples from Johor, Melaka, and Negeri Sembilan (South) were clustered together in one group while samples from Perak, Kedah, Penang, Selangor, Kelantan, and Terengganu (North and East Coast) were in another clustered group.
Intestinal parasitic infections (IPIs) are still major health problems in many developing countries including Malaysia, particularly in the poor and socioeconomically deprived rural and remote communities in Peninsular Malaysia. This study was conducted to determine the prevalence of IPIs and to identify the key factors associated with intestinal polyparasitism as well as to evaluate the knowledge, attitude and practices (KAP) on IPIs among rural Orang Asli and Malay communities in Terengganu, Malaysia.
Impact of northern and southern air mass transport on the temporal distribution of atmospheric (210)Po and (210)Pb in the east coast of Johor, Malaysia
- Environmental science and pollution research international
- Published over 2 years ago
Concentration activities of (210)Pb and (210)Po in the PM10 were determined to discuss their distribution and chemical behavior in relation to meteorological parameters especially in air mass transport during monsoon events. Marine aerosol samples were collected between January 2009 and December 2010 at the coastal region of Mersing, which is located in the southern South China Sea and is about 160 km northeast of Johor Bahru, as part of the atmosphere-ocean interaction program in Malaysia. About 47 PM10 samples were collected using the Sierra-Andersen model 1200 PM10 sampler over a 2-year sampling campaign between January 2009 and December 2010. Samples were processed using acid digestion sequential extraction techniques to analyze various fractions such as Fe and Mn oxides, organic matter, and residual fractions. While, (210)Pb and (210)Po activities were measured with the Gross Alpha/Beta Counting System model XLB-5 Tennelec® Series 5 and the Alpha Spectrometry (model Alpha Analyst Spectroscopy system with a silicon-surface barrier detector), respectively. The distribution activities of (210)Pb and (210)Po in the PM10 samples were varied from 162 to 881 μBq/m(3) with mean value of 347 ± 170 μBq/m(3) and from 85 to 1009 μBq/m(3) with mean value of 318 ± 202 μBq/m(3), respectively. The analysis showed that (210)Po activity in our samples lies in a border and higher range than global distribution values due to contributions from external sources injected to the atmosphere. The speciation of (210)Pb and (210)Po in marine aerosol corresponds to transboundary haze; e.g., biomass burning especially forest fires and long-range air mass transport of terrestrial dust has enriched concentrations of particle mass in the local atmosphere. The monsoon seems to play an important role in transporting terrestrial dust from Indo-China and northern Asia especially during the northeast monsoon, as well as biogenic pollutants originating from Sumatra and the southern ASEAN region during southwest monsoon events.