Browse publications by year: 2019

  1. Fulltext Sociodemographic determinants of good sexual and reproductive health (SRH) knowledge among secondary school children in Kuantan, Pahang, Malaysia
    Raja Nurul Najwa Raja Ismail, Halimatus Sakdiah Minhat
    Malaysian Journal of Medicine and Health Sciences, 2019;15(2):104-111.
    MyJurnal
    Introduction: Adolescence being a transition phase from a child to an adult, commonly associated with high-risk sexual behaviours, which put them at risks of sexually transmitted diseases (STD), HIV and unwanted pregnancy. All these risks can be prevented by having adequate knowledge on sexual and reproductive health (SRH). Hence, this study aimed to determine the sociodemographic determinants of good SRH knowledge among secondary school children in Kuala Kuantan, Pahang Malaysia. Methods: A cross-sectional study was conducted among 687 sec- ondary school children in Kuala Kuantan, Kuantan, Pahang, using self-administered questionnaire. A multistage cluster sampling was employed to recruit the respondents. Three levels of analysis were conducted to describe the characteristics of the respondents and determining the determinants of good SRH knowledge. Data was analysed using Statistical Package of IBM SPSS Statistics Version 24 and the p value was set to be less than 0.05. Results: The proportion with good SRH knowledge was 58.4%. Upper secondary school age group (AOR 7.142, 95% CI: 4.830, 10.560) and smokers (AOR 2.597, 95% CI: 1.348, 5.004) were found to be significant determinants of good SRH knowledge. Conclusions: The percentage of respondents with good SRH knowledge was just slightly above average. As expected, older school children has the strongest likelihood of having good SRH knowledge. Whether the good SRH knowledge is contributed by the existing SRH curriculum is unclear and requires further exploration. In view of the alarming SRH issues involving younger school children, strategic plan are needed to instil the knowledge at earlier age.
  2. Fulltext Effect of honey cocktail on macular thickness, retinal nerve fiber layer thickness and optic nerve head parameters in post-menopausal women
    Premala Devi Sivagurunathan, Noorlaila Baharuddin, Zunaina Embong, Raja Norliza Raja Omar, Nurzulaikha Abdullah, Yee, Cheng Kueh, et al.
    Malaysian Journal of Medicine and Health Sciences, 2019;15(2):93-103.
    MyJurnal
    Introduction: Honey postulated may have an estrogenic effect on the retinal estrogenic receptors. The aim of the study is to compare the mean macular thickness, retinal nerve fiber layer (RNFL) thickness and optic nerve head (ONH) parameters with and without honey cocktail supplement in post-menopausal women. Methods: A ran- domised interventional study was conducted from March 2014 to July 2015. A total of 60 post-menopausal women were selected and randomised into 2 groups: honey cocktail (20 mg/day) and control. Macular thickness, RNFL thickness and ONH parameters were measured using optical coherence tomography at baseline and at 3 months post honey cocktail supplementation. Results: The mean global macular thickness and RNFL thickness were signifi- cantly thicker in post-menopausal women with honey cocktail at 3 months post supplement (p = 0.002 and 0.033 respectively). There was a significant increase in the mean change of global macular thickness and RNFL thickness in honey cocktail group at 3 months post supplement (p < 0.001 and < 0.001 respectively). Although there was no significant difference in the ONH parameters at 3 months post supplement between the two groups but there was significant increase in the mean change of rim area (p = 0.003), and significant reduce in the mean change of cup area (p = 0.001) and cup-disc-ratio (p
  3. Fulltext Risk factors of insulin refusal among type 2 diabetes mellitus patients with poor glycaemic control at Tanglin Health Clinic, Kuala Lumpur
    Puvanese Rebecca Pillai Simon, Salmiah Md. Said, Ahmad Zaid Fattah, Shamsul Azhar Shah
    Malaysian Journal of Medicine and Health Sciences, 2019;15(2):84-92.
    MyJurnal
    Introduction: The number of patients with poor glycaemic control who refuse insulin therapy is alarming. Factors that contribute to insulin refusal are important to study to identify high risk groups so that appropriate measures can be taken to prevent progression of uncontrolled diabetes. The objective of this study is to determine the risk factors of insulin refusal among type 2 diabetes mellitus patients with poor glycaemic control at Tanglin Health Clinic, Kuala Lumpur, Malaysia. Methods: A case control study was conducted among 216 cases and 230 controls using stratified sampling method. Cases were defined as patients with HbA1C more than 7.5% but not on insulin therapy despite being offered by the doctor whereas controls consist of patients with HbA1C of more than 7.5% but already on insulin therapy. Data was collected from April until May 2018, using a self-administered questionnaire. Analysis was done via IBM SPSS version 23.0. Results: Response rate for cases was 93.9% and response rate for controls was 100%. Risk factors of insulin refusal among poor glycaemic control includes age above 60 years old, tertiary level education, duration of diabetes less than 10 years, poor level of knowledge on insulin, fear on injection pain and fear to bruising due to injections. Conclusion: Hence, efforts must be taken to tackle the modifiable factors such as knowledge on insulin and diabetes, and fear on injections and bruises.
  4. Fulltext Determining the merit of inferior vena cava distensibility index in the estimation of fluid responsiveness in ventilated septic patient in intensive care unit
    Mohd Zulfakar Mazlan, Farah Nursuhada Mohd Subakir, Shamsul Kamalrujan Hassanin
    Malaysian Journal of Medicine and Health Sciences, 2019;15(2):77-83.
    MyJurnal
    Introduction: There is no single haemodynamic parameters either static central venous pressure (CVP) or dynamic stroke volume variation, inferior vena cava distensibility index (SVV,IVCd) that can be used precisely to assess fluid responsiveness. It must be performed concurrently with clinical assessment. Therefore, this study was conducted to determine the correlation between these 3 parameters. Methods: This was a cross sectional non-interventional study conducted in intensive care unit. Each patient who fulfilled the criteria will have their CVP, SVV and IVCd measured instantaneously. Analysis of correlation was done using bivariate (Pearson) correlation, while agreement between SVV and IVCd was assessed using Cohen’s Kappa analysis. Results: A total of 37 patients were enrolled in this study. 70.3% were males and 29.7% were females. Mean age was 59.7 ± 13.3. Mean APACHE score was 24.1 ± 6.1. IVCd had significant positive correlation with SVV (r = 0.391, p = 0.017). Agreement between IVCd and SVV was 0.329 (0.95 CI = 0.0174 – 0.6412; p = 0.033). There was non-significant negative correlation between IVCd with CVP and SVV with CVP with r = -0.155 (p=0.359) and r = -0.068 (p= 0.691) respectively. Conclusion: There is only fair cor- relation between IVCd and SVV in determining fluid responsiveness. However, CVP does not correlate to both SVV and IVCd. Neither one of them is a good method in assessing fluid responsiveness during standard care in our centre. Therefore, the usage of above methods needs to combine with clinical parameters to yield better result.
  5. Five New Species of Guimaraesiella (Phthiraptera: Ischnocera) from Broadbills (Aves: Passeriformes: Calyptomenidae: Eurylaimidae)
    Gustafsson DR, Malysheva OD, Tolstenkov OO, Bush SE
    J Parasitol, 2019 12;105(6):846-857.
    PMID: 31730418
    Five new species of Guimaraesiella Eichler, 1949 are described and illustrated from hosts in the Eurylaimidae and Calyptomenidae. They are Guimaraesiella corydoni n. sp. from Corydon sumatranus laoensis Meyer de Schauensee, 1929 ; Guimaraesiella latirostris n. sp. from Eurylaimus ochromalus Raffles, 1822 ; Guimaraesiella cyanophoba n. sp. from Cymbirhynchus macrorhynchus malaccensis Salvadori, 1874 and C. m. siamensis Meyer de Schauensee and Ripley, 1940 ; Guimaraesiella altunai n. sp. from Calyptomena viridis caudacuta Swainson, 1838 ; and Guimaraesiella forcipata n. sp. from Eurylaimus steerii steerii Sharpe, 1876 . These represent the first species of Guimaraesiella described from the Calyptomenidae and Eurylaimidae, as well as the first species of this genus described from the Old World suboscines.
    MeSH terms: Animals; Bird Diseases/parasitology*; Female; Malaysia; Male; Philippines; Thailand; Tick Infestations/parasitology; Tick Infestations/veterinary*; Passeriformes/parasitology*; Ischnocera/anatomy & histology; Ischnocera/classification*
  6. Fulltext The Biological Evaluation of Conventional and Nano-Hydroxyapatite-Silica Glass Ionomer Cement on Dental Pulp Stem Cells: A Comparative Study
    Hii SC, Luddin N, Kannan TP, Ab Rahman I, Nik Abdul Ghani NR
    Contemp Clin Dent, 2019;10(2):324-332.
    PMID: 32308298 DOI: 10.4103/ccd.ccd_581_18
    BACKGROUND: Despite their lower strength, glass ionomer cements (GICs) are widely used as restorative materials because of their anti-cariogenic properties, direct adhesion to tooth structure and good biocompatibility. Recently, the addition of nano-hydroxyapatite (nano-HA)-silica to conventional GIC (cGIC) has been shown to improve the strength of cGIC. However, the biocompatibility and cell attachment properties of this material are unknown.

    AIMS: This study aims to evaluate and compare the cytotoxicity and cell attachment properties of cGIC and nano-HA-silica-GIC on dental pulp stem cells (DPSCs).

    METHODS AND MATERIALS: Material extracts of nano-HA-silica-GIC and cGIC were prepared into seven serial dilutions and applied to 96 well plates seeded with DPSCs. After 72 h, the cell viability was determined using MTT assay. The DPSCs cell attachment properties were examined under scanning electron microscope (SEM) after 24 and 72 h. Kruskal-Wallis test was used to analyse the data for MTT assay (P < 0.05). SEM images of cell attachment properties were also described.

    RESULTS: Nano-HA-silica-GIC and cGIC was shown to be slight to non-cytotoxic at all concentrations, except 200 mg/ml. Moderate cytotoxicity has been observed at 200 mg/ml concentration where nano-HA-silica-GIC and cGIC revealed cell viability values of 44.38 and 42.15%, respectively. Nano-HA-silica-GIC demonstrated better cell viability values than cGIC at all concentrations except for 6.25 and 12.5 mg/ml. Nevertheless, the results were not statistically significant (P > 0.05). SEM examination revealed the increasing numbers of DPSCs attached to both groups with prominent filopodia, especially after 72 h.

    CONCLUSIONS: Nano-HA-silica-GIC exhibited good biocompatibility which is comparable to cGIC and favoured the attachment of DPSCs.

  7. Fulltext LCMS/MS metabolite profiling and analysis of acute toxicity effect of the ethanolic extract of centella asiatica on zebrafish model
    Fauziahanim Zakaria, Wan Norhamidah Wan Ibrahim, Intan Safinar Ismail, Hafandi Ahmad, Nurhuda Manshoor, Norhadiani Ismail, et al.
    Pertanika Journal of Science & Technology, 2019;27(2):985-1003.
    MyJurnal
    Centella asiatica or known as ‘pegaga’ in Malaysia, is a popular medicinal herb, which is being used as main ingredient or incorporated into various herbal products. Apart from efficacy, the chemical profile and potential toxic effect of the plant are two important aspects of concern towards ensuring product satisfaction and safety of consumers. This paper reports the qualitative and quantitative chemical analysis of the leaf ethanolic extract of C. asiatica using LCMS/MS. The acute toxiciy effect of the extract and selected marker chemical constituents were further analysed using a zebrafish model. Twenty constituents, were identified and the main chemical marker constituents of the plant viz asiaticoside, asiatic acid, and madecassic acid were further quantified. Asiaticoside was found to be present in higher concentration than the other marker constituents. Meanwhile in the acute toxicity test, the LD50 of the extract on the zebrafish model was determined to be 1250 mg/L while 100% mortality was observed at the highest test concentration of 2500 mg/L. However, acute toxicity evaluation on four marker triterpenoids of the herb, i.e asiatic acid, madecassic acid, asiaticoside and madecassoside, indicated them to be quite safe on the zebrafish model, with no mortality shown for test concentrations between 10 to 500 mg/kg BW.
  8. Fulltext Chemical constituents and biological activities of South East Asia marine sponges: a review
    Lee, Kah Nyan, Maulidiani, Faridah Abas, Ahmed, Mediani, Leong, Sze Wei, Intan Safinar Ismail, et al.
    Pertanika Journal of Science & Technology, 2019;27(2):953-983.
    MyJurnal
    The ocean has an exceptional resource with various groups of natural products that are potentially useful for biomedical and other applications. Marine sponges have prominent characteristic natural products with high diversity. They produce many vital therapeutic metabolites with prominent biological activities. Marine invertebrates and microbial communities are the primary producers of such metabolites. Among the richest sources of these metabolites, class Demospongiae and the order Haplosclerida and genus Xestopongiae from family Petrosiidae are of interest. This review summarizes the research that has been conducted on two classes, eight orders, twelve families and fourteen genera of marine sponges available in the South East Asia region, covering the literature of the last 20 years. Ninety-five metabolites including alkaloids, sterols, terpenoids, quinones isolated from marine sponges collected in South East Asia along with their bioactivities especially cytotoxicity and antibacterial activities were reported in this review. Chemistry and biology are highly involved in studying marine sponges. Thus, tight collaboration is needed for understanding their taxonomy aspects. This review will outline chemistry and biological aspects, challenge, limitation, new idea and a clear future perspective on the discovery of new drugs from South East Asia’s marine sponges.
  9. Fulltext Post-weaning exposure to Bisphenol a induces histological changes in the liver
    Siti Sarah Mohamad Zaid, Siti Nur Hajar Rohim, Goh, Yong Meng, Noordin Mohamed Mustapha
    Pertanika Journal of Science & Technology, 2019;27(2):943-951.
    MyJurnal
    Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) widely used in industry as a plasticizer for the production of polycarbonate plastics and epoxy resins. The liver is highly sensitive to BPA, even at low doses. The objective of the study is to investigate the effect of BPA on histo-architecture of the liver in post-weaning rats. Post-weaning female rats were exposed to BPA by oral gavage over a six weeks period. The results showed that even at low environmental doses, BPA exposure had adverse effects on the liver histoarchitecture, thereby disrupting the functions of cellular. The administration of BPA resulted in severe hepatocytes necrosis, dilated sinusoid, and depicting features of conspicuous Kupffer cells. The results may be due to the generation of reactive oxygen species (ROS) by BPA. In conclusion, post-weaning exposure of BPA resulted in significant histological alterations due to ROS generation.
  10. Fulltext Quality of life among patients with brain pathology in a Malaysian hospital
    Das, Priscilla, Naing, Nyi Nyi, Nadiah Wan Arfah, KO, Naing Noor Jan, Yee, Cheng Kueh, Rasalingam, Kantha
    Pertanika Journal of Science & Technology, 2019;27(2):921-931.
    MyJurnal
    The objective of this study was to determine the prevalence of symptoms and problems in Malaysian brain pathology patients. A total of 100 respondents in Kuala Lumpur Hospital were included in this cross-sectional study. The study utilized European Organization for Research and Treatment of Cancer Quality Of Life questionnaire (EORTC QLQ-C30). Patient with a “symptom/problem” having the minimum response of “a little”. A response of “quite a bit” was defined as having a “severe symptom/problem”. The two most prevalent “symptoms/problems” among the neurological disorder patients were fatigue (65%; severe: 28%) and reduced cognitive functioning (64%; severe: 25%). The mean number of “symptoms/problems” ranged from 4.63 (meningioma) to 6.80 (cerebellar edema) while the mean number of “severe symptoms/problems” ranged from 1.39 (astrocytic glioma) to 2.8 (cerebellar edema). Therefore special attention should be given to these patients in order to improve the overall quality of life of the patients.
  11. Fulltext The Execution of the Green Building Project in Klang Valley, Malaysia: A Pilot Study
    Nor Kalsum Mohd Isa, Albahori, Ainul Samihah, Kamarul Ismail, Anuar Alias
    Pertanika Journal of Science & Technology, 2019;27(2):911-919.
    MyJurnal
    Execution of the green building project specifically among the housing developers in Malaysia is still at its infancy. As of August 2016, there are only 16 housing projects certified by the Green Building Index (GBI) under the category of Residential New Construction (RNC) since the assessment systems established in 2010. The authors address this issue in the context of the factors affecting the execution of the green building project among the housing developers in Klang Valley. A pilot study by using questionnaire survey was conducted among 30 housing developers from 10 different zones divided by the Ministry of Housing and Local Government, Malaysia. This paper aimed to report the results of the reliability test of the designed questionnaire. The results based on the Cronbach’s Alpha analysis showed that the items used in the questionnaire were reliable and obtained an acceptable level of internal consistency, which were relevant for the main study. The pilot study revealed that only 9 out of 30 respondents had the completed or ongoing green building projects. The findings exposed the level of knowledge, emotion, value, attitude, behavior and the potential factors affecting the execution of the green building projects among the housing developers in Klang Valley.
  12. Fulltext The influence of change management and e-learning in Malaysian private higher education institutions
    Sukumaran, Sheila Devi
    Pertanika Journal of Science & Technology, 2019;27(2):897-910.
    MyJurnal
    The purpose of this research is to analyse the influence of change management and e-learning in Malaysian private higher education institutions focusing on educators’ perspectives. The conceptual framework was modified in combination of various theories from Systemic Change Models and E-learning Cycle Models. A self-administered questionnaire adapted from Siebel 4.0-2 Survey Questionnaires (SSQ) by Hambling, 2010 was the data collection instrument. The sample consisted of educators from private higher education institutions with visions or missions based on e-learning implementation in Malaysia. As per findings, through review of the visions and missions, the selected private higher education institutions integrated teaching and learning with Stepwise Multiple regression analysis, has a significant relationship on independent variables that contribute to e-learning implementation.
  13. Fulltext Fire test and effects of fire retardant on the natural ability of timber: a review
    Sulaiha Ali, Siti Aslina Hussain, Mohd Zahirasri Mohd Tohir
    Pertanika Journal of Science & Technology, 2019;27(2):867-895.
    MyJurnal
    Timber is one of the most sustainable and renewable raw materials available. Globally, it has been increasingly used for the manufacture of home and workplace furniture. Timber products are known to have ignition resistance and a low heat release rate. These characteristics delay burning and maintain the structural durability of a product, protecting both the occupants and their properties in a fire. Timber, however, experiences thermal degradation during combustion, yielding smoke, heat, toxic gases, and char when burned. To understand the fire conduct of timber, extensive knowledge in its process of decomposition is essential. This paper, therefore, reviewed the methods of flammability tests widely employed to investigate the reaction of timber and timber-based product to fire, namely cone calorimeter test, room-corner test, limiting oxygen index (LOI) test, furnace test, and single burning item test (SBI). In addition, an overview of the fire retardant treatments; impregnation and coatings was also presented. The potential effects of fire retardants on the durability, strength, hygroscopicity, corrosion, machinability, glueing characteristics, and paintability of the timber were also highlighted.
  14. Fulltext A side-sensitive modified group runs control chart with auxiliary information to detect process mean shifts
    Mim, Faijun Nahar, Saha, Sajal, Chong, Michael Khoo Boon, Khatun, Mahfuza
    Pertanika Journal of Science & Technology, 2019;27(2):847-866.
    MyJurnal
    This study aims to develop a side-sensitive modified group runs control chart using auxiliary information (SSMGR-AI) to enhance the speed of detecting mean shifts in a process. The average run length (ARL) and expected average run length (EARL) criteria are adopted as performance measures of the proposed chart. The performance of the proposed chart is compared to the exponentially weighted moving average chart with AI (EWMA-AI) and the run sum chart with AI (RS-AI), in terms of the ARL and EARL criteria. The results reveal that the optimal SSMGR-AI chart generally outperforms all charts under comparison for detecting shifts in the process mean. An application with numerical data is presented to elaborate the implementation of the SSMGR-AI chart.
  15. Fulltext Water quality characteristic of the National Hydraulic Research Institute of Malaysia (NAHRIM) lake undergoing remediation by the constructed wetlands: a baseline study
    Aliyu, Aliyu Danjuma, Go, Rusea, Hishamuddin Omar, Syazrin Syima Sharifuddin, Azroie Muhammad, Bashirah Fazli
    Pertanika Journal of Science & Technology, 2019;27(2):565-587.
    MyJurnal
    This study was conducted to determine the baseline water quality characteristics of a contaminated NAHRIM lake undergoing remediation by the constructed wetlands, based on the physico-chemical and biological parameters. The sampling was conducted for six months (May-October) in 2016 from 5 stations of the lake and analysed using APHA standard methods for water and wastewater analysis, while Malaysian water quality index (WQI) was used to calculate quality of the lake. The results showed that, the Conductivity, Dissolved Oxygen, NO3-N, NO2-N, PO4, Temperature, Turbidity, TDS, TSS, and Zn were under class I, while pH, B and COD were categorized under class II. NH3-N, BOD, Fe, Escherichia coli, Total coliform and Mn were categorized as class III. Moreover, Al was not given any classification under NWQS but their concentration did not exceed EPA guidelines. Furthermore, as compared to the water samples from the constructed wetlands that reported a class III WQI, the lake was observed to show an overall class II WQI. This is suggestive of the retaining and remedial role of the constructed wetlands being the first point of contact for the contaminants going to the lake. Thus the lake is suitable for recreational activities.
  16. Fulltext A functional data approach to the estimation of mortality and life expectancy at birth in developing countries
    Syazreen Niza Shair, Nur Azhani Zolkifli, Nur Faiqah Zulkefli, Azizah Murad
    Pertanika Journal of Science & Technology, 2019;27(2):797-814.
    MyJurnal
    The functional data model has recently received increasing attention particularly in their application to mortality forecasting. The advantage of this method over the well-known Lee-Carter model is the ability to treat the underlying process as functional, and provide estimations that are robust to outliers. This research investigates the accuracy of functional data approach in estimating the mortality rates and life expectancy at births in developing countries including Malaysia, Indonesia, Thailand and Singapore. The functional data method was applied to these countries’ mortality data, and the out-sample forecast errors showed that, in terms of overall, the functional data model was more accurate than that of the original Lee-Carter model for males and females. The results provide evidence that the functional model is accurate to forecast the life expectancy at births for developing countries.
  17. Fulltext Real and complex wavelet transform approaches for Malaysian speaker and accent recognition
    Rokiah Abdullah, Muthusamy, Hariharan, Vijean, Vikneswaran, Zulkapli Abdullah, Farah Nazlia Che Kassim
    Pertanika Journal of Science & Technology, 2019;27(2):737-752.
    MyJurnal
    A new approach for speaker and accent recognition based on wavelets, namely Discrete Wavelet Packet (DWPT), Dual Tree Complex Wavelet Packet Transform (DT- CWPT) and Wavelet Packet Transform (WPT) based non-linear features are investigated. The results are compared with conventional MFCC and LPC features. k-Nearest Neighbors (k-NN), Support Vector Machine (SVM) and Extreme Learning Machine (ELM) classifier are used to quantify the speaker and accent recognition rate. The database for the research was developed using English digits (0~9) and Malay words. The highest accuracy for speaker recognition obtained is 93.54% while for accent recognition; it is 95.86% using Malay words. Combination of features for speaker recognition is obtained from ELM classifier is 98.68 % and for accent recognition is 98.75 % using Malay words.
  18. Fulltext Evaluating the surrounding physical habitat for Thynnichthys Thynnoides’s spawning areas using a visual-based habitat assessment at Rui river, Perak
    Mohamad Radhi Amonodin, Rohasliney Hashim, Mohammad Noor Amal Azmai, Zarul Hazrin Hashim
    Pertanika Journal of Science & Technology, 2019;27(2):703-714.
    MyJurnal
    This study was conducted to evaluate the physical habitat of spawning areas for Thynnicthys thynnoides (T. thynnoides) in the Rui River, Gerik, Perak. Five sampling sites of Rui River’s floodplain were chosen. Sampling was conducted between May and October 2015 by using a visual-based habitat assessment developed for Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers: Periphyton, Benthic Macroinvertebrates and Fish. This study showed that T. thynnoides still migrated to the upper stream of Rui River during spawning season mainly in August. Habitat assessment scoring indicated that the physical habitat structure of Rui River fell into a suboptimal category, which was most likely able to support fish populations and thus providing a suitable habitat for T. thynnoides during the spawning season. Conclusively, it was observed that the T. thynnoides population was dependent on environmental conditions.
  19. Fulltext An overview on biodegradation of carbamate pesticides by soil bacteria
    Mohd Yunus Abd Shukor, Wan Lutfi Wan Johar, Normala Halimoon, Mohammed Umar Mustapha
    Pertanika Journal of Science & Technology, 2019;27(2):547-563.
    MyJurnal
    Carbamates are poisonous pesticides which have been used widely in agriculture production for decades. Unlike other pesticides such as organophosphate, carbamate pesticides are not persistent in the environment however, their degradation is crucial due to their toxicity to living system. The World Health Organization, categorized carbamate pesticide as toxic, hazardous and restricted for use. Example of carbamates pesticides include Carbaryl, Aldicarb, Methomyl, Carbofuran, and Propoxur. They are extensively used to control many insect and pests of crops. Presently, there is significant awareness regarding the negative effects of pesticides due to their ability to pollute soil and water bodies. Most pesticides are readily degraded or metabolized by microbes. Carbamate pesticide degradation by microorganisms relies not only on the availability of microbes with suitable biodegradative enzymes, but also on the various ecological factors. This reviewarticle outlines the present development in biodegradation of carbamate pesticides, their toxicity and enzymatic degradation as well as their degradative pathways.
  20. Fulltext Analysis of oil palm leaf phyllotaxis towards development of models to determine the fresh fruit bunch (FFB) maturity stages, yield and site-specific harvesting
    Zulfadhli Mustafa Albakri, Muhamad Saufi Mohd Kassim, Ahmad Fikri Abdullah, Hazreen Haizi Harith
    Pertanika Journal of Science & Technology, 2019;27(2):659-672.
    MyJurnal
    In order to ensure the optimum quality of palm oil, oil palm fruit needs to be harvested at the optimum maturity to avoid free fatty acid (FFA) accumulation. The high content of FFA not only reduces the quality of palm oil but also increases the refining cost. Optimum maturity based on plantation standard operating procedure (SOP) is determined by identifying the tree with loose fruit on the ground. The matured bunch is further identified based on the colour of the bunch. This paper presents a research work on formulation and validation of mathematical equations to estimate the maturity stages (age in weeks) of fresh fruit bunch (FFB) based on FFB position in oil palm phyllotaxis (spiral leaves arrangement) as an additional feature to confirm the maturity level of oil palm FFB. Regression analysis showed that the proposed method was able to estimate the maturity stages of oil palm FFB with the coefficient of determination R2 = 0.9 and a root mean square error (RMSE) of 1.58 weeks. The FFB yield estimation model and harvesting can be created based on the extracted data using the formula which will help in the planning of harvesting operation. Plantation manager can use this information to generate yield variability map and estimate the appropriate number of workers and machine. Planned harvesting operation can save a significant amount of time in site harvesting operation.
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