11 research outputs found

    Remote sensing for mapping RAMSAR heritage site at Sungai Pulai Mangrove Forest Reserve, Johor, Malaysia.

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    The Sungai Pulai Mangrove Forest Reserve (SPMFR) is the largest riverine mangrove system in Johore. In 2003 about 9,126 ha of the Sungai Pulai mangrove was designated as a RAMSAR site. RAMSAR sites are wetland areas that are deemed to have international importance and are included in the List of Wetlands of International Importance. The SPMFR plays a significant socio-economic role to the adjacent 38 villages. Satellite remote sensing is a useful source of information where it provides timely and complete coverage for vegetation mapping especially in mangroves where the accessibility is difficult. This study was carried out to identify and map land cover types using SPOT-4 imagery at the Sungai PulaiRAMSAR site and its surrounding areas. Through unsupervised classification technique a total of seven classes of land cover type were mapped, where about 90% mapping accuracy was gained from the accuracy assessment. Later, vegetation densities were classified into five levels namely very high, high, medium, low and very low based on crown density scale using vegetation indices model such as NDVI, AVI and OSAVI. Results from NDVI and OSAVI model were almost similar but AVl model detected more on medium vegetation which did not show the real ground condition. The study concludes that SPOT-4 imagery was able to discriminate mangrove area clearly from other land covers type. Vegetation indices model can be used as a tool for mapping vegetation density level in the SPMFR and its surrounding area. Therefore Vl:s models from remote sensing are useful to monitor and manage the mangrove forest for sustainable management and preserve the SPMFR as a RAMSAR site in Peninsular Malaysia

    Factors affecting commencement and cessation of smoking behaviour in Malaysian adults

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    <p>Abstract</p> <p>Background</p> <p>Tobacco consumption peak in developed countries has passed, however, it is on the increase in many developing countries. Apart from cigarettes, consumption of local hand-rolled cigarettes such as <it>bidi </it>and <it>rokok daun </it>are prevalent in specific communities. Although factors associated with smoking initiation and cessation has been investigated elsewhere, the only available data for Malaysia is on prevalence. This study aims to investigate factors associated with smoking initiation and cessation which is imperative in designing intervention programs.</p> <p>Methods</p> <p>Data were collected from 11,697 adults by trained recording clerks on sociodemographic characteristics, practice of other risk habit and details of smoking such as type, duration and frequency. Smoking commencement and cessation were analyzed using the Kaplan-Meier estimates and log-rank tests. Univariate and multivariate Cox proportional hazard regression models were used to calculate the hazard rate ratios.</p> <p>Results</p> <p>Males had a much higher prevalence of the habit (61.7%) as compared to females (5.8%). Cessation was found to be most common among the Chinese and those regularly consuming alcoholic beverages. Kaplan-Meier plot shows that although males are more likely to start smoking, females are found to be less likely to stop. History of betel quid chewing and alcohol consumption significantly increase the likelihood of commencement (p < 0.0001), while cessation was least likely among Indians, current quid chewers and kretek users (p < 0.01).</p> <p>Conclusions</p> <p>Gender, ethnicity, history of quid chewing and alcohol consumption have been found to be important factors in smoking commencement; while ethnicity, betel quid chewing and type of tobacco smoked influences cessation.</p

    Remote Sensing For Mapping Ramsar Heritage Site At Sungai Pulai Mangrove Forest Reserve, Johore, Malaysia

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    The Sungai Pulai Mangrove Forest Reserve (SPMFR) is the largest riverine mangrove system in Johore State. In 2003 about 9,126 ha of the Sungai Pulai mangrove was designated as a RAMSAR site. RAMSAR sites are wetland areas that are deemed to have international importance and are included in the List of Wetlands of International Importance. The SPMFR playa significant role for socio-economic to the adjacent 38 villages. The villagers depends on the estuary as its mudflats, an ideal feeding, spawning and fattening ground, support a significant proportion of fish species. Other mangrove uses include wood cutting, charcoal production, aquaculture activities and eco-tourism. The current development of Iskandar Development Region (IDR) and construction of a new port at the river estuary may represent a direct impact on the mangrove ecosystem, causing shorelines erosion and water pollution from associated reclamation and dredging works. However the conservation management of the site is managed in line with Integrated Management'Plan for the sustainable use of mangroves in Iohor state. Satellite remote sensing'is a useful source of information as it provides timely and complete coverage for vegetation mapping especially in mangroves where the access is difficult. This study was carried out to identify and map land cover types using SPOT 4 image in the Sungai Pulai-RAMSAR site and its surrounding areas. Unsupervised classification technique has produce eight classes of land cover type over the study site. Ground verification was carried out to verify and assess the accuracy of classification. The results showed that approximately 90% of the area was classified correctly. Vegetation density was classified into five levels namely very high, high, medium, low and very low based on crown density scale. The study concludes that SPOT 4 was capable to discriminate mangrove area clearly from other land covers type, meanwhile vegetation indices model can be used as a tool for mapping vegetation density level in the SPMFR and its surrounding area. Results clearly showed usefulness of remote sensing for monitoring, management and development of mangrove forest for sustainable management and preserve the SPMFR as a RAMSAR site in Peninsular Malaysia

    Influence of Ground Tyre Rubber Devulcanisates on Morphology and Properties of Tread Tyre Formulation

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    The use of reclaimed and devulcanised material in virgin rubber compounds has attracted the attention of many rubber industries due to increasing raw material costs, diminishing resources and growing awareness of environmental issues. Several methods have been developed to reclaim rubber waste, for example, thermo-and chemo-mechanical processes, microwave regeneration, microbial action and ultrasonic regeneration. However, extensive research on processes for high-quality recycling materials based on waste tyres is still lacking. In this study, optimised processing conditions for the devulcanisation of whole passenger car tyres using diphenyldisulphide (DPDS) as a devulcanisation aid will be applied. The devulcanised ground tyre rubber (D-GTR) obtained from the process was blended on top of the original tyre tread formulation at different concentrations. The results so far indicate that the addition of D-GTR influences the properties of the blend, but to a lesser extent than the commercially used powder or reclaim types do, for which loadings less than 5% can be applied. The main reason for the influence of D-GTR on the rubber properties is inhomogeneities in the D-GTR/virgin rubber blend and quality aspects of raw GTR

    Analysis of ketamine and norketamine in hair samples using molecularly imprinted solid-phase extraction (MISPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS)

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    An anti-ketamine molecularly imprinted polymer (MIP) was synthesized and used as the sorbent in a solid-phase extn. protocol to isolate ketamine and norketamine from human hair exts. prior to LC-MS/MS anal. Under optimized conditions, the MIP was capable of selectively rebinding ketamine, a licensed anesthetic that is widely misused as a recreational drug, with an apparent binding capacity of 0.13 μg ketamine per mg polymer. The limit of detection (LOD) and lower limit of quantification (LLOQ) for both ketamine and norketamine were 0.1 ng/mg hair and 0.2 ng/mg hair, resp., when 10 mg hair were analyzed. The method was linear from 0.1 to 10 ng/mg hair, with correlation coeffs. (R2) of better than 0.99 for both ketamine and norketamine. Recoveries from hair samples spiked with ketamine and norketamine at a concn. of 50 ng/mg were 86% and 88%, resp. The method showed good intra- and interday precisions
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