Effects of gamma irradiation on egg hatchability, pupation, and adult emergence of the immature stages of the oriental fruit fly, Bactrocera dorsalis (hendel) (diptera: tephritidae) from Malaysia

Studies on the effect of irradiation on egg hatchability, pupation and adult emergence of the immature stages of the Oriental Fruit Fly, Bactrocera dorsalis (Hendel) was conducted in Malaysian Nuclear Agency, Dengkil, Selangor, Malaysia using a Co-60 source. Eggs, 1st instars to 3rd instars larvae and pupae stages were treated separately with dosages 50Gy to 400Gy to determine the most tolerance stage and the optimum dose for provide quarantine security. Each treatment involves a minimum of 100 individuals for each dose with four replications. The hatch from eggs to 1st instar larvae, pupation from eggs and all of three instars larvae to pupae, and eclosion from pupae to adult, were used as criteria to determine the effect of irradiation. Egg hatch was completely inhibited by 100Gy for early egg and 300Gy for late eggs. Dose of 200Gy and 250Gy were able to prevent completely pupation when treated from egg stage and 1st instar larvae, respectively. Unfortunately, those dosages did not affect pupation when applied to 2nd and 3rd instars, but it did prevent any from emerging as adults. Adult emergence was 100% prevented when eggs and all larvae were treated at 100Gy as compared to pupae was not completely prevented even by 400Gy. Among the four immature stages of B. dorsalis, the 3rd instar larvae (inside fruits) and pupae (outside fruits) were found to be the most tolerance stage and the early eggs are the most susceptible stage to irradiation. Our results suggest that minimum dose 100 to 150Gy is sufficient to provide a high level of quarantine security against this important pest and the dose might allow for irradiation be accepted as a quarantine treatment for most tropical fruits from Malaysia

Antibiotics resistance of Vibrio spp. isolated from diseased seabass and tilapia in cage culture

Vibriosis has become one of the most important bacterial diseases in marine cultured organisms in recent years. This study was focusing on isolation and identification of Vibrio spp. isolated from diseased seabass (Lates calcarifer), tilapia (Oreochromis niloticus) and seawater from Sri Tujuh lagoon in East Coast of Malaysia; also determination of antibiotic resistance patterns among Vibrio spp. Vibrio species isolated from diseased seabass in Pantai Sri Tujuh, Tumpat, Kelantan were screened for their antibiotic sensitivity patterns by Kirby-Bauer method. A total of 47 isolates belonging to three different species were identified which are V. parahaemolyticus, V. vulnificus, and V. alginolyticus. In this study, high incidence of erythromycin, chloramphenicol and sulfamethoxazole resistance was observed among the Vibrio isolates, whereas all isolates were susceptible to oxytetracycline. Vibrio isolates were 96% resistant to one or more different classes of antibiotic, and 17 different resistance patterns were identified. The MAR index of 0.4 indicating the Vibrio spp. in these farmed fish might have been indiscriminately and continuously exposed to those antibiotics during culturing stages of the fish. This study showed that multidrug-resistant Vibrio spp. were common in diseased seabass and tilapia cultured at Sri Tujuh lagoon. These essential findings suggested involvement of seafood in transmission of these pathogen to human. In addition, oxytetracycline can be used as a treatment to combat vibriosis in diseased seabass and tilapia

Antibiotics Resistance of Vibrio spp. Isolated from Diseased Seabass and Tilapia in Cage Culture

Vibriosis has become one of the most important bacterial diseases in marine cultured organisms in recent years. This study was focusing on isolation and identification of Vibrio spp. isolated from diseased seabass (Lates calcarifer), tilapia (Oreochromis niloticus) and seawater from Sri Tujuh lagoon in East Coast of Malaysia; also determination of antibiotic resistance patterns among Vibrio spp. Vibrio species isolated from diseased seabass in Pantai Sri Tujuh, Tumpat, Kelantan were screened for their antibiotic sensitivity patterns by Kirby-Bauer method. A total of 47 isolates belonging to three different species were identified which are V. parahaemolyticus, V. vulnificus, and V. alginolyticus. In this study, high incidence of erythromycin, chloramphenicol and sulfamethoxazole resistance was observed among the Vibrio isolates, whereas all isolates were susceptible to oxytetracycline. Vibrio isolates were 96% resistant to one or more different classes of antibiotic, and 17 different resistance patterns were identified. The MAR index of 0.4 indicating the Vibrio spp. in these farmed fish might have been indiscriminately and continuously exposed to those antibiotics during culturing stages of the fish. This study showed that multidrug-resistant Vibrio spp. were common in diseased seabass and tilapia cultured at Sri Tujuh lagoon. These essential findings suggested involvement of seafood in transmission of these pathogen to human. In addition, oxytetracycline can be used as a treatment to combat vibriosis in diseased seabass and tilapia

Insight into the origin of chikungunya virus in Malaysian non-human primates via sequence analysis

Chikungunya virus (CHIKV) is maintained in the sylvatic cycle in West Africa and is transmitted by Aedes mosquito species to monkeys. In 2006, four verified CHIKV isolates were obtained during a survey of arboviruses in monkeys (Macaca fascicularis) in Pahang state, Peninsular Malaysia. RNA was extracted from the CHIKV isolates and used in reverse transcription polymerase chain reactions (RT-PCR) to amplify PCR fragments for sequencing. Nucleic acid primers were designed to generate overlapping PCR fragments that covered the whole viral sequence. A total of 11,238 base pairs (bp) corresponding to open reading frames (ORFs) from our isolates and 47 other registered isolates in the National Center for Biotechnology Information (NCBI) were used to elucidate sequences, amino acids, and phylogenetic relationships and to estimate divergence times by using MEGA 7.0 and the Bayesian Markov chain Monte Carlo method. Phylogenetic analysis revealed that all CHIKV isolates could be classified into the Asian genotype and clustered with Bagan Panchor clades, which are associated with the chikungunya outbreak reported in 2006, with sequence and amino acid similarities of 99.9% and 99.7%, respectively. Minor amino acid differences were found between human and non-human primate isolates. Amino acid analysis showed a unique amino acid at position 221 in the nsP1region, at which a glycine (G) was found only in monkey isolates, whereas arginine (R) was found at the same position only in human isolates. The time to the most recent common ancestor (MRCA) estimation indicated that CHIKV probably started to diverge from human to non-human primates in approximately 2004 in Malaysia. The results suggested that CHIKV in non-human primates probably resulted from the spillover of the virus from humans. The study will be helpful in understanding the movement and evolution of CHIKV in Malaysia and globally. © 2019 The Author(s

Electrochemistry of Hg(II) Salts in Room-Temperature Ionic Liquids

The electrochemistry of HgCl(2) and [Hg(NTf(2))(2)] ([NTf(2)](-) = bis-{(trifluoromethyl)sulfonyl}imide) has been studied in room temperature ionic liquids. It has been found that the cyclic voltammetry of Hg(II) is strongly dependent on a number of factors (e.g., concentration, anions present in the mixture, and nature of the working electrode) and differs from that found in other media. Depending on conditions, the cyclic voltammetry of Hg(II) can give rise to one, two, or four reduction peaks, whereas the reverse oxidative scans show two to four peaks. Diffuse reflectance UV-vis spectroscopy and X-ray powder diffraction have been used to aid the assignment of the voltammetric waves

Marshall stability properties of asphaltic concrete with kaolin clay under aging

The influence of kaolin clay on marshal stability properties of asphaltic concrete AC14 at different aging conditions was presented in this study. These aging conditions were named as un-aged, short-term, and long-term aging. The conventional asphalt binder of penetration grade 60/70 was used in this investigation. Four different levels of kaolin clay replacement were employed (i.e. 0%, 3%, 6%, and 9% by binder weight). Asphalt concrete mixes were prepared at selected optimum asphalt content (5%). The performance was evaluated based on Marshall Stability and voids characteristics. Results indicated the improving stability performance that the mixes modified with kaolin clay have under aging conditions. The result also showed that the use of 6% to 9% kaolin clay can produce more durable asphalt concrete mixtures with better serviceability

Marshall stability properties of asphaltic concrete with kaolin clay under aging

The influence of kaolin clay on marshal stability properties of asphaltic concrete AC14 at different aging conditions was presented in this study. These aging conditions were named as un-aged, short-term, and long-term aging. The conventional asphalt binder of penetration grade 60/70 was used in this investigation. Four different levels of kaolin clay replacement were employed (i.e. 0%, 3%, 6%, and 9% by binder weight). Asphalt concrete mixes were prepared at selected optimum asphalt content (5%). The performance was evaluated based on Marshall Stability and voids characteristics. Results indicated the improving stability performance that the mixes modified with kaolin clay have under aging conditions. The result also showed that the use of 6% to 9% kaolin clay can produce more durable asphalt concrete mixtures with better serviceability

Refinement of the ISO 9126 model for evaluating software product quality in e-Book

Despite the widespread use of e-Book in education, there is yet a standard framework for evaluating the quality of software products in e-Book.Research efforts mainly focus on technological breakthroughs and limited to attention has been given to the evaluation of software product quality.As such, this paper aims to propose a refinement of the ISO 9126 model for evaluating software product quality in e-Book.Popular Software Quality Models are reviewed including McCall, Boehm, FURPS, Dromey and ISO 9126.Refinements to ISO 9126 resulted in the identification of five quality characteristics (Functionality, Reliability, Usability, Efficiency,Portability) and 16 sub -characteristics (Suitability, Accurateness, Security, Interoperability, Maturity, Fault Tolerance, Recoverability, Understandability, Learnability, Operability, Attractiveness, Time Behavior, Adaptability, Installability, Coexistence, Replaceability).There are two contributions of this work: a Software Quality Model for e-Book; and the identification of quality metrics to support the evaluation of software product. The refined model provides a formal method for evaluating software product quality in e- Book and the quality metrics serves as a foundation for the development of survey instruments and computer support system. It is hoped that this work would spark interest for the development of better e- Book applications