Antimicrobial activity and essential oils of Curcuma aeruginosa,Curcuma mangga,and Zingiber cassumunar from Malaysia

Objective:To analyze the chemical composition of the essential oils of Curcuma aeruginosa (C.aeruginosa),Curcuma mangga(C.mangga),and Zingiber cassumunar(Z.cassumunar). and study their antimicrobial activity.Methods:Essential oils obtained by steam distillation were analyzed by gas chromatography-mass speclrometry(GC-MS).The antimicrobial activity of the essential oils was evaluated against four bacteria:Bacillus cereus(H.cereus).Staphylococcus aureus(S.aureus).Escherichia coli(E.coli).and Pseudomonas aeruginosa(P.aeruginosa);and two fungi:Candida albicans(C.albicans) and Cyptococcus neoformans(C.neoformans),using disc-diffusion and broth microdilution methods.Results:Cycloisolongifolene,8.9-dehydro-9- formyl(35.29%) and dihydrocoslunolide(22.51%) were the major compounds in C.aeruginosa oil; whereas caryophyllene oxide(18.71%) and caryophyllene(12.69%) were the major compounds in C.mangga oil:and 2,6.9,9-tetramethyl-2.6.10-cycloundecatrien-1-one(60.77%) andα-caryophyllene(23.92%) were abundant in Z.cassumunar oil.The essential oils displayed varying degrees of antimicrobial activity against all lested microorganisms.C.mangga oil had the highest and most broad-spectrum activity by inhibiting all microorganisms tested,with C.neoformans being the most sensitive microorganism by having the lowest minimum inhibitory concentration(MIC) and minimum fungicidal concentration(MFC) values of 0.1μL/mL. C.aeruginosa oil showed mild antimicrobial activity,whereas Z.cassumunar had very low or weak activity against the tested microorganisms.Conclusions:The preliminary results suggest promising antimicrobial properties of C.mangga and C.aeruginosa,which may be useful for food preservation,pharmaceutical treatment and natural therapies.

Impact of coastal development on mangrove cover in Kilim river, Langkawi Island, Malaysia

We examined the impact of various coastal developments on mangrove cover along the Kilim River, Langkawi Island, Malaysia between 1996 and 2008. We analysed images from Systeme Probatoire d＇Observation de la Tarre （SPOT） of Kilim River using supervised classification and Principal Component Analysis （PCA）. Over 8% （176.83 ha] of mangrove cover was degraded along the Kilim River from its total area of 2153.07 ha during the past 14 years. We identified several causes of mangrove degradation, including mangrove clearing （38%）, mangrove conversion to commercial area （21%）, residential area （19%）, agriculture （12%）, aquaculture （12%） and wake current （6%）. Langkawi is one of the main tourism islands in Malaysia. Tthe pace of coastal development throughout the entire island including Kilim River had suppressed the mangroves propagation over the years. Long term monitoring of mangrove ecosystems is essentials to ensure the survival and sustainability of mangrove associated biodiversity.

Antimicrobial activity of mangrove plant(Lumnitzera littorea)

Objective:To investigate the antimicrobial activities of n-hexane.ethyl acetate and methanol extracts of the leaves of Lumnitzera littorea(L littorea) against six human pathogenic microbes. Methods:The antimicrobial activity was evaluated using disc diffusion and microdilution methods.Results:The antimicrobial activities of the crude extracts were increased with increasing the concentration.It is clear that n-hexane extract was the most effective extract. Additionally.Gram positive Bacillus cereus(B.cereus) appear to be the most sensitive strain while Pseudomonas aeruginosa(P.aeruginosa) and the yeast strains(Candida albicans(C. albicans) and Cryptococcus neoformans(C.neqformans)) appear to be resistance to the tested concentrations since no inhibition zone was observed.The inhibition of microbial growth at concentration as low as 0.04 mg/ml.indicated the potent antimicrobial activity of L littorea extracts.Conclusions:The obtained results are considered sufficient for further study to isolate the compounds responsible for the activity and suggesting the possibility of finding potent antibacterial agents from L littorea extracts.

Apoptosis,antimicrobial and antioxidant activities of phytochemicals from Garcinia malaccensis Hk.f

Objective:To study the chemical constituents of stembark of Garcinia malaccenm（G.malaccenm） together with apoptotic.antimicrobial and antioxidant activities.Methods:Purification and structure elucidation were carried out by chromatographic and spectroscopic techniques, respectively.MTT and trypan blue exclusion methods were performed to study the cytotoxic activity.Antibacterial activity was conducted by dise diffusion and microdilulion methods, whereas antioxidant activities were done by ferric thiocyanate method and DPPH radical scavenging.Results:The phylochemical study led lo the isolation ofα,β-mangostin and cycloarl-24-en-3β-ol.α-Mangostin exhibited cytotoxic activity against HSC-3 cells with an IC50 of 0.33μM.β- andα-mangostin showed activity against K562 cells with IC50 of 0.40μM and 0.48μM,respectively,α-Mangostin was active against Gram-positive bacteria, Staphylococcus aureus（S.aureus） and Bacilus anthracis（B.anthmcis） with inhibition zone and MIC value of（19 mm;0.02S mg/mL） and（20 mm;0.013 mg/mL）,respectively.In antioxidant assay,α-mangostin exhibited activity as an inhibitor of lipid peroxidation.Conclusions:G.malaccenm presenceα- andβ-mangostin and cycloart-24-en-3β-ol.β-Mangostin was found very active against H.SC-3 cells and KS62.The results suggest that mangoslins derivatives have the potential to inhibit the growth of cancer cells by inducing apoptosis.In addition,α-andβ-mangostin was found inhibit the growth of Cram-positive pathogenic bacteria and also showed the activity as an inhibitor of lipid peroxidation.

Geochemistry of the Rare Earth Elements (REE) Distribution in Terengganu Coastal Waters: A Study Case from Redang Island Marine Sediment

A study on the rare earth elements (REEs) of Redang Island marine sediments was conducted in August 2011 during the premonsoon season. Bottom sediments were collected from 27 sampling stations on board UMT Discovery II vessel using a Smith McIntyre grab and analyzed for rare earth elements (REEs) using inductively coupled plasma mass spectrometry (ICP-MS). Results showed that the REEs patterns in sediments reflected the source rock patterns with an overall order of abundance such as: light rare earth elements (LREE) > middle rare earth element (MREE) > high rare earth elements (HREE). The chondrite normalized patterns of REEs showed enrichment of LREEs over HREEs with La/Yb of 13.6 while the chondrite normalized value showed low (Gd/Yb)N ratios (2.12) which was illustrated in the flat HREE pattern. The chondrite normalized REE patterns of sediments showed the enrichment of LREE and depletion of HREE. From our findings, REEs concentrations in the study area were found to be of geogenic origins and the distributions were not influenced by anthropogenic sources.

In vitro antimicrobial activity of mangrove plant Sonneratia alba

Objective:To investigate the antimicrobial property of mangrove plantSonneratia alba(S. alba).Methods:The antimicrobial activity was evaluated using disc diffusion and microdilution methods against six microorganisms. Soxhlet apparatus was used for extraction with a series of solvents,n-hexane, ethyl acetate and methanol in sequence of increasing polarity.Results:Methanol extract appeared to be the most effective extract whilen-hexane extract showed no activity. The antimicrobial activities were observed against the gram positive bacteria Staphylococcus aureus(S. aureus) and Bacillus cereus(B. cereus), the gram negative Escherichia coli(E. coli) and the yeast Cryptococcus neoformans. Pseudomonas aeruginosa and Candida albicans appeared to be not sensitive to the concentrations tested since no inhibition zone was observed.E. coli(17.5 mm) appeared to be the most sensitive strain followed by S. aureus(12.5 mm)and B. cereus(12.5 mm).Conclusions:From this study, it can be concluded that S. alba exhibit santim icrobial activities against certain microorganisms.

Feed-Forward Artificial Neural Network Model for Air Pollutant Index Prediction in the Southern Region of Peninsular Malaysia

This paper describes the application of principal component analysis (PCA) and artificial neural network (ANN) to predict the air pollutant index (API) within the seven selected Malaysian air monitoring stations in the southern region of Peninsular Malaysia based on seven years database (2005-2011). Feed-forward ANN was used as a prediction method. The feed-forward ANN analysis demonstrated that the rotated principal component scores (RPCs) were the best input parameters to predict API. From the 4 RPCs, only 10 (CO, O3, PM10, NO2, CH4, NmHC, THC, wind direction, humidity and ambient temp) out of 12 prediction variables were the most significant parameters to predict API. The results proved that the ANN method can be applied successfully as tools for decision making and problem solving for better atmospheric management.

Galactagogue effects of Musa x paradisiaca flower extract on lactating rats

Objective:To investigate the potential of Musa x paradisiaca(M.x paradisiaca)flower extracts in promoting milk production of lactating rats and its effects on growth of the suckling pups. Methods:Galactagogue activity was evaluated in terms of quantity of milk produced from the rats treated with petroleum ether,ethanol or water extracts of the flower.Lactating rats(n=5) of Spraque Dawley with six pups each were administered with the extracts in the amount of 500 mg/kg body weight,while the control rats were given an equivalent amount of distilled water.The rats were daily administered via oral feeding starting from Day 5 until Day 14 and the performance of milk production was measured along the experimental period by weight-suckle-weight method. Results were statistically analyzed using SPSS by means of ANOVA at 0.05 and was expressed as their mean±standard deviation.The rates of pups’ growth were measured as the weight gain along the experimental period.Results:The rats treated with aqueous extract produced higher milk than control and ethanol groups.Aqueous extract was identified to increase milk production by 25%,while petroleum ether extract by 18%.The mean of yields produced by the rats during suckling period for aqueous,petroleum ether,ethanol and control were 4.62±2.45,4.37±1.93,3.65±1.89 and 3.69±1.79,respectively.Growth rates of pups for the rats treated with control,aqueous, ethanol extract and petroleum ether were(1.85±0.49),(1.78±0.56),(1.65±0.46)and(1.56±0.42) g/pup, respectively.Conclusions:The present study reveals the potential of M.x paradisiaca flower to enhance milk production of nursing mothers which could be exploited for commercialization of the isolated extract.

Rigid‑Body Analysis of a Beveled Shape Structure in Regular Waves Using the Weakly Compressible Smoothed Particle Hydrodynamics(WCSPH)Method

In many cases of wave structure interactions,three-dimensional models are used to demonstrate real-life complex environ-ments in large domain scales.In the seakeeping context,predicting the motion responses in the interaction of a long body resembling a ship structure with regular waves is crucial and can be challenging.In this work,regular waves interacting with a rigid foating structure were simulated using the open-source code based on the weakly compressible smoothed par-ticle hydrodynamics(WCSPH)method,and optimal parameters were suggested for diferent wave environments.Vertical displacements were computed,and their response amplitude operators(RAOs)were found to be in good agreement with experimental,numerical,and analytical results.Discrepancies of numerical and experimental RAOs tended to increase at low wave frequencies,particularly at amidships and near the bow.In addition,the instantaneous wave contours of the sur-rounding model were examined to reveal the efects of localized waves along the structure and wave dissipation.The results indicated that the motion response from the WCSPH responds well at the highest frequency range(ω>5.235 rad/s).

Conservation and Utilization of Crop Genetic Resources in Malaysia： Mardi＇s Effort

Malaysian Agriculture Research and Development Institute （MARDI） is the country＇s major custodian of the nation＇s crops genetic resources. It has a global responsibility in the conservation of genetic resources of banana, sweet potato and citrus, and national responsibility for the conservation of crops, such as rice, tropical fruits and some herbs and medicinal plant species. MARDI rice seed genebank at Seberang Prai in the state of Penang was established in 1984 and currently holds 12,770 registered rice accessions, of which 53% are of local origin. In addition, MARDI also conserves genes in the field, mostly for underutilized tropical fruit genetic resources. At present, about 168 species of underutilized, rare and wild tropical fruit species consisting of about 2,000 accessions, the largest in the country, are being conserved. The species include ＂kuini＂ （Mangifera odorata）, ＂bacang＂ （Mangifera foetida）, ＂binjai＂ （Mangifera caesia）, ＂cerapu＂ （ Garcinia praniana）, ＂rambai＂ （Baccaurea motleyana）, ＂asam gelugor＂ （ Garcinia atroviridis）, ＂terap＂ （drthocarpus odoratissimus） and ＂pulasan＂ （Nephellium rambutan-ake）. The accessions are mostly conserved ex situ in field genebanks located at the various MARDI stations throughout the country. Although the conservation of the various crop species genetic resources is important, the real challenge is enhancing its utilisation. The main objective of the paper was to share and disseminate information related to works conducted and strategies opted by MARDI on the conservation and utilization of crop genetic resources. Information on species of crops that are available in MARDI＇s genebank was also highlighted together with brief information of some of the associated traits of significant importance posses by those genetic resources.

Assessing the Potential of Mangrove Educotourism to Marine Protected Area: A Case of Tioman and Tulai Islands, Pahang, Malaysia

Mangroves composition and species are richly diverse in Tioman and Tulai Island. A total of 23 mangrove species have been found consisting of exclusive and non-exclusive species in Kg. Juara, Kg. Nipah, Kg. Paya, Kg. Genting and Tulai Island. The abundance mangrove species are Rhizophora X lamarckii, Rhizophora apiculata, Rhizophora mucronata and Brugueira gymnorrhiza. From supervised classification, total of 59.90 hectares mangrove covers have been identified in both islands, with 86.49% in Tioman Island (52.76 hectares) and 13.51% in Tulai Island (7.14 hectares). A new hybrid species has been found (Rhizophora X lamarckii) dominated in Tulai Island, combination between Rhizophora stylosa and Rhizophora apiculata. At the mean time only mangrove area in Teluk Bakau, Tulai Island is considered as the focal destination of tourists to the area. However, other mangrove areas in Tioman Island are also potential to be promoted as tourist destination areas. Although the mangrove area is only a part of the scenery, its presence obviously enhances tourist attraction. The basic facilities such as information counter, walking trails, garbage boxes and toilets are considered necessary. The main information panel and site map should be provided on the mangrove sites. Boardwalks may be constructed for visitor to access the mangrove area without destroying the root system and stand. The actual site of these facilities and on-site information guides should be strategically placed in order to provide beneficial information and as well as to sustain the biophysical stability of the sites. Since mangroves provide various important functions in nature, it hopes that the mangrove educotourism activity will influence the people and community’s attitudes to the environment, conservation and sustainable development in a very positive way.

Zinc-doped hydroxyapatite-zeolite/polycaprolactone composites coating on magnesium substrate for enhancing in-vitro corrosion and antibacterial performance

This work is focused on developing zinc-doped hydroxyapatite-zeolite(Zn HA-Zeo)and polycaprolactone(PCL)composite coatings on magnesium(Mg)substrate to improve the corrosion resistance and antimicrobial properties.Dip-coating technique was used to coat Zn HA-Zeo/PCL on the Mg substrate at room temperature.The samples were subjected to field emission scanning electron microscopy(FESEM),X-ray diffraction(XRD),Fourier transform infrared(FTIR),energy dispersive X-ray spectroscopy(EDX)and antimicrobial potential.Results demonstrated that composite coatings consist of HA,scholzite,zeolite,and PCL phases.EDX spectra indicated the presence of calcium(Ca),silicon(Si),aluminum(Al),zinc(Zn),phosphorus(P)and oxygen(O).The composite surface appeared in spherical-like microstructure on coating with thickness ranging 226-260μm.Zinc-doped HA-Zeo composite coating had a high corrosion resistance and provided sufficient protection to the Mg surface against galvanic corrosion.Doped Zn HA-Zeo coating samples exhibited superior disc inhibition by confirming antimicrobial activity against the E.coli as compared to HA-Zeo sample.Altogether these results showed that the Zn HA-Zeo coatings not only improved the corrosion resistance,but also enhanced the antimicrobial property and hence they can be used as suitable candidates for implant applications.

Zinc-oxide nanoparticle-based saturable absorber deposited by simple evaporation technique for Q-switched fiber laser

A Q-switched erbium-doped fiber laser(EDFL)incorporating zinc-oxide(ZnO)nanoparticles-based saturable absorber(SA)is proposed and demonstrated.To form the SA,the ZnO nanoparticles,which are originally in the powder form,are first dissolved in ethanol and subsequently deposited onto the surface of fiber ferrule by using the adhesion effect with the evaporation technique.By integrating the ZnO nanoparticle-based SA into a laser cavity of an EDFL,a self-started and stable Q-switching is achieved at a low threshold power of 20.24 mW.As the pump power is increased,the pulse repetition rate is tunable from 10.34 kHz to 25.59 kHz while pulse duration decreases from 21.39μs to 3.65μs.Additionally,this Q-switched laser has a maximum energy per pulse of 19.34 nJ and an average output power of 0.46 mW.These results indicate the feasibility and functionality of the ZnO nanoparticles-based SA for Q-switched generation,which offers the flexibility and easy integration of the SA into a ring laser cavity.

Optical Code Generating Device Using 1×N Asymmetric Hollow Waveguide Couplers

An optical code generating device for security access system application is presented. The code generating device constructed using asymmetric hollow optical waveguide coupler design provides a unique series of output light intensities which are successively used as an optical code. The design of the waveguide is made using two major components which are asymmetric Y-junction splitter and a linear taper. Waveguiding is done using a hollow waveguide structure. Construction of higher level 1×N hollow waveguide coupler is done utilizing a basic 1×2 asymmetric waveguide coupler design together with a cascaded design scheme. Non-sequential ray tracing of the asymmetric hollow optical waveguide couplers is performed to predict the optical transmission properties of the waveguide. A representation of the code combination that can be generated from the device is obtained using combinatory number theory.

Longtail Tuna (Thunnus tonggol) Consumption Frequency in Terengganu, Malaysia

In Terengganu, Longtail tuna or Thunnus tonggol is one of the most popular marine fishes landed by fishermen and has a high demand among customers. This species often served with a unique local delicacy called Nasi Dagang and Ikan Singgang, one of the favourite meals during breakfast by local communities. Since people have always consumed this species, therefore this study aims to identify the consumption rate of this species among Terengganu people. Specifically, this survey data obtained from 124 respondents, ages ranged from 15 to 60 years old from five districts in Terengganu, including Besut, Kuala Nerus, Kuala Terengganu, Hulu Terengganu, and Kemaman. Generally, the estimated amount of this species consumption is 239.7 g per person and 1.83 times per week. From the formula calculated, the amount of this species consumed by one person is 437.4 g/person/week. This value can use to calculate the permissible tolerable weekly intake (PTWI) to estimate the intake of pollutants, such as heavy metals in the human body.

Broad bandwidth SOA-based multiwavelength laser incorporating a bidirectional Lyot filter

We demonstrate a broad bandwidth multiwavelength laser based on a bidirectional Lyot filter and a semiconductor optical amplifier with a mechanism of intensity-dependent loss as the flatness agent. A wide bandwidth of a multiwavelength spectrum of 32.9 nm within a 5 dB uniformity is obtained under optimized polarization param- eters. For this case, the number of generated lasing lines is 329 with a fixed wavelength separation of 0.1 nm. The power stability of this multiwavelength laser is less than 1.35 dB within 200 min time frame. This shows that the bidirectional Lyot filter provides an alternative option for multiwavelength generation in laser systems.