Fabrication of Cationic Exchange Polystyrene Nanofibers for Drug Delivery

Purpose: To prepare polystyrene nanofiber ion exchangers (PSNIE) with surface cation exchange functionality using a new method based on electrospinning and also to optimize crosslinking and sulfonation reactions to obtain PSNIE with maximum ion exchange capacity (IEC).Method: The nanofibers were prepared from 15% w/v polystyrene solution in dimethylacetamide (DMAc) containing 0.025 %w/v tetrabutylammonium bromide (TBAB) using electrospinning technique, followed by crosslinking with sulfuric acid/formaldehyde in a ratio ranging from 100/0 to 50/50 v/v and sulfonation in sulfuric acid. Degree of crosslinking was determined as the amount of fibers that remained in dichloromethane. The morphology and diameter of the fibers were evaluated by scanning electron microscopy (SEM) while IEC of PSNIE was performed by salt splitting titration.Results: PSNIE crosslinked with a sulfuric acid/formaldehyde ratio of 90/10 with 0.1 %w/v silver sulfate for 10 min at 70°C and sulfonated in 98 % sulfuric acid with 0.2 %w/v silver sulfate as the catalyst at 100°C for 30 min showed a maximum IEC of 3.21 meq/g-dry-PSNIE. Increase in  sulfonation temperature caused the IEC of PSNIE to increase due to faster sulfonation. It was observed that the higher the temperature the faster the rate of sulfonation reaction. The diameter of the fibers after sulfonation was 404 ± 42 nm.Conclusion: These results indicate that PSNIE can be successfully prepared by electrospinning. Furthermore, cationic drug can be loaded onto the novel PSNIE for controlled release delivery.Keywords: Polystyrene, Ion exchange capacity, Nanofibers, Ion exchangers, Crosslinking, Sulfonation

Economic valuation of recreational resources in rural area

Quantitative studies on economic value of resources in rural area are carried out by determining the benefits gained by the tourists using the resources at the site. The value then can be used to imply the importance of conservation of resources to the communities. As many rural tourism destinations depend on the natural resources to be the main product of the tourism development, failure to take measures to conserve the natural resources in rural areas may cause overuse and sometime leading to irreversible damage. An alternative way to determine the value of resources is by using the travel cost method (TCM) which is an environmental valuation technique. TCM is site specific. Modification to the basic travel cost model (TCM) will account for other factors that may influence the demand for the rural tourism resources. The benefit from resources will be measured through the determination of a recreation demand curve for a particular site using the concept of consumer surplus. Hence, this paper intends to highlight the usefulness of economic valuation for a sustainable rural tourism setting and the biases of basic TCM which in turn induces the need for a modified TCM to obtain a perfect measure of the value of resources to tourist

Demand model of international visitors to the Kilim Karst Geoforest Park, Langkawi : application of ITCM model

Kilim Karst Geoforest Park in Langkawi offers rural tourism attractions to the visitors. The rural tourism demand model of international visitors to the site can be developed using the non-market valuation techniques. One of the common techniques is using the revealed preference technique, which is the Travel Cost Model (TCM). There have been various modifications made to the basic TCM developed by Clawson 1959. Modification of the basic TCM takes into account other factors that may shift the demand of visitors. The individual travel cost model (ITCM) has been employed in the research. Thus, the main objective of this article is to develop the rural tourism demand model for the park using the individual travel cost model (ITCM). In addition, the basic TCM model is estimated to determine the consumer surplus value of the international visitors to the park. Structured questionnaire and face-to-face data collection method are employed to obtain the primary data from 330 international visitors using the convenient sampling technique. Poisson regression analysis has been conducted to estimate the basic TCM model. The finding for ITCM shows that the consumer surplus value per trip for the Langkawi model €6993 is greater than for the Kilim models (€1437 and €633) for the Poisson regression analysis

Total economic value of ecosystem services in Malaysia: a review

Southeast Asia contains the world’s third largest tropical forests, currently experiencing a high deforestation rate, thus highlighting the need for conservation efforts. The full potential of ecosystem services in tropical forests has never been completely quantified in economic or monetary terms. This potential value is accessible by extraction of readily available information in both market and non-market terms. As such, an economic valuation approach is capable to estimate the full range of an ecosystem services benefits provided by a tropical forest. This paper reviews the suitable indicators pertinent to a Total Economic Value (TEV) of tropical forests to propose a conceptual framework for the TEV of Tropical Forest in Southeast Asia. The failure to impute price on ecosystems services in tropical forests would result in a misguided policy and the society would be in detrimental as a result of misallocation of resources

Exploring economic valuation and impact of rural tourism

Economic valuation studies can be used to determine conservation values of resources to consumers. Since rural tourism development depends greatly on the availability of natural resources, an economic valuation of natural resources can be used to gauge sustainability of rural tourism in the future. In addition, economic impact studies on rural tourism development will convey the effect of the development on employment, business and government revenue in the region. The findings from these studies could be beneficial to policy makers in terms of making appropriate decisions on the conservation of natural resources and rural tourism development in Malaysia. There are various methods used by researchers for economic valuation and economic impact studies. Hence this paper intends to bring to light the function of these studies in the development of rural tourism. Besides, the paper also highlights the usefulness of these studies for policy makers, state governments and park managers in terms of making appropriate plans for the development of tourism particularly in rural areas. Finally, it intends to explore various methods used in these studies by researchers

Fish hobbyists’ willingness to donate for wild fighting fish (Betta livida) conservation in Klang Valley

Betta livida is an endangered endemic species of wild fighting fish affected by habitat degradation and exploitation. Despite this concern, the literature on the conservation of wild betta is negligible. Conservation is a non-use value, whereas the species itself is a use-value because they are sought after in the ornamental fish trade business. Therefore, the contingent valuation method (CVM) was applied in this study to establish the monetary value for species conservation by determining hobbyists’ willingness to donate (WTD) for conservation. Fish hobbyists are the most prominent backbone of the industry and are the most acquainted with the targeted species. Hence, hobbyists’ knowledge, perceptions and attitude towards species conservation have also been explored and weighed against the WTD. Purposive sampling was employed with a total of 150 respondents in Klang Valley. The findings show that the WTD was influenced by double-bound CVM, age (AGE) and hobbyists who owned the species (OWNB). In contrast, knowledge, perceptions and attitudes were not significant. Using probit regression analysis, hobbyists’ WTD for species conservation was MYR 9.04 annually. The survey also revealed concern for species that are wild-caught by hobbyists. Hence, the results of this study offer preliminary insights into the WTD for wild betta and local freshwater fish conservation in Malaysia

Carbon stock and sequestration valuation in a mixed dipterocarp forest of Malaysia

Forest degradation and deforestation are some of the major global concerns as they can reduce the forest carbon stock and sequestration capacity. However, the carbon stock and sequestration potential in a mixed dipterocarp tropical forest remains unclear due to a lack of information. This study was carried out on the carbon stock and estimated its economic value to justify its conservation. Six plots were established in the Endau Rompin National Park, Johor and subplots measuring 50 × 20 m were established in each plot. All trees greater than 15 cm DBH (diameter at breast height) were identified and the parameters measured included tree height and diameter. The aboveground carbon (AGC) content was about 222 Mg(C) ha-1, belowground carbon (BGC) was 53 Mg (C) ha-1 and it was 6 Mg (C) ha-1 for other components. In total, the carbon stock amounted to 281 Mg (C) ha-1. On the other hand, the total CO2 sequestrated in the mixed dipterocarp forest amounted to 1,040 t CO2 ha-1. The carbon value was estimated at RM32,240 t CO2 ha-1 or $7,280 t CO2 ha-1. Therefore, the study found that the dipterocarp forest should be preserved to mitigate greenhouse gas emissions

Demand of international visitors to the Kilim Karst Geoforest Park Langkawi

Kilim Karst Geoforest Park (KKGP) offers pristine nature based attractions to visitors. Apart from local visitors, the park receives many international visitor arrivals from all over the world. The demand model of international visitors to the park can be developed using one of the common environmental valuation techniques, the Travel Cost Method (TCM). The Individual Travel Cost Model (ITCM) has been employed in the research. Thus, the article develops the demand model of international visitors to the KKGP and determines the economic value of the park. Structured questionnaire and face-to-face data collection method are employed to obtain the primary data from 330 international visitors using the purposive sampling technique. The analysis using the Poisson regression shows that the travel cost, time cost, quality of site, age and education variables, are significant at 95% confidence level. The consumer surplus per visitor/year is found to be €216 or RM 864, whilst the economic value of the park is estimated to be €27 million or RM 108 million. Findings from the study will be useful for Langkawi Development Authority (LADA) to justify on monetary allocations made by the federal government for the tourism development at the park

Travel cost adjustment of international multiple destination visitors to the Kilim Karst Geoforest Park, Langkawi, Malaysia

Kilim Karst Geoforest Park (KKGP) located in Langkawi island offers pristine nature-based attractions to visitors. Apart from local visitors, the park receives many international visitor arrivals from all over the world. The demand model of international visitors to the park can be developed using one of the common environmental valuation techniques, the Travel Cost Method (TCM). And, using the demand curve, the benefit obtained by the international visitors to the park can be estimated using the concept of consumer surplus. In this research, the Individual Travel Cost Model (ITCM) has been employed. One of the common issues in travel cost studies is to obtain the specific travel cost attributable to the specific location for multiple destination visitors. Thus, the article determines the consumer surplus value of international visitors from the travel cost adjustment. A structured questionnaire and face-to-face data collection method were employed to obtain the primary data from 330 international visitors using the purposive sampling technique. The study has found that the consumer surplus estimated using the unadjusted travel cost model was greater than for the adjusted travel cost model thus suggesting an overestimation of the benefit gained by visitors. The consumer surplus value was estimated to be ϵ 216/ RM 864

Economic valuation using Travel Cost Method (TCM) IN Kilim Karst Geoforest Park, Langkawi, Malaysia

Kilim Karst Geoforest Park is a special conservation area within a Permanent Forest Reserve (PFR), consisting of limestone landscape, an extensive mangrove forest system, beaches, coastal wetlands and islands. However, the limestone, forest reserve and mangrove areas have been identified as environmentally sensitive, and are under threat by development activities. Currently, there is a lack of information on the economic benefits of the geoforest park, in terms of services. A demand model of international visitors to the Kilim Karst Geoforest Park (KKGP) was derived and compared the benefit estimated using both travel cost and consumer surplus adjustment techniques. The Travel Cost Method (TCM) has been employed to derive the demand model, whilst the concept of consumer surplus was used for value determination and comparison. The findings showed that the benefit estimated using travel cost adjustments, based on satisfaction attained, is euro288,000,000, and number of hours spent in the park is euro141,000,000, which was greater than that for the consumer surplus adjustment based on satisfaction attained euro278,640,000 and number of hours spent euro123,840,000. The study proposed the travel cost adjustment technique findings rather than the consumer surplus adjustment technique, since it was based on specific KKGP model estimation. In conclusion, the findings on the monetary value of the geoforest park will alert the community regarding the importance of conserving KKGP