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Comparative Study of the Effects of Fluconazole and Voriconazole on Candida glabrata, Candida parapsilosis and Candida rugosa Biofilms
No full textInfections by non-albicans Candida species are a life-threatening condition, and formation of biofilms can lead to treatment failure in a clinical setting. This study was aimed to demonstrate the in vitro antibiofilm activity of fluconazole (FLU) and voriconazole (VOR) against C. glabrata, C. parapsilosis and C. rugosa with diverse antifungal susceptibilities to FLU and VOR. The antibiofilm activities of FLU and VOR in the form of suspension as well as pre-coatings were assessed by XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction assay. Morphological and intracellular changes exerted by the antifungal drugs on Candida cells were examined by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results of the antibiofilm activities showed that FLU drug suspension was capable of killing C. parapsilosis and C. rugosa at minimum inhibitory concentrations (MICs) of 4× MIC FLU and 256× MIC FLU, respectively. While VOR MICs ranging from 2× to 32× were capable of killing the biofilms of all Candida spp tested. The antibiofilm activities of pre-coated FLU were able to kill the biofilms at ¼× MIC FLU and ½× MIC FLU for C. parapsilosis and C. rugosa strains, respectively. While pre-coated VOR was able to kill the biofilms, all three Candida sp at ½× MIC VOR. SEM and TEM examinations showed that FLU and VOR treatments exerted significant impact on Candida cell with various degrees of morphological changes. In conclusion, a fourfold reduction in MIC50 of FLU and VOR towards ATCC strains of C. glabrata, C. rugosa and C. rugosa clinical strain was observed in this study
Does colour matter? Genetic differentiation of colour morphs of the Asian golden web spider Nephila antipodiana (Araneae: Nephilidae)
No full textHere we present the first attempt to test for genetic differentiation among four distinct colour morphs of the Asian golden web spider Nephila antipodiana Walckenaer. Fragments of the 18S rRNA (18S) and cytochrome c oxidase subunit I (COI) genes were sequenced in eight populations of N. antipodiana belonging to four distinct colour morphs: Yellow, yellowish green, and two newly discovered morphs, reddish yellow and white-spotted. The nuclear sequences amplified from females of the four colour morphs were identical. The mitochondrial COI sequences, on the other hand, revealed slightly higher variation by recovering three haplotypes belonging to two different clades. Clade I comprises yellow, yellowish green and reddish yellow morphs from the mainland of Southeast Asia and Java, whereas clade II is restricted to white-spotted morph originating from Borneo. The low genetic divergence between both clades, despite being distinctive, undoubtedly provides new insight into the genetic diversity of this polymorphic species
Serological evidence of high leptospira exposure among indigenous people (Orang Asli) in peninsular Malaysia using a recombinant antigen-based ELISA
No full textThe lifestyles of the indigenous people (Orang Asli) of Peninsular Malaysia who traditionally live close to the forest, put them at higher risk of exposure to zoonotic diseases. Leptospirosis has recently emerged as one of the most important diseases of public health concern. Here, we aimed to obtain a baseline data on the level of Leptospira exposure among the 107 Orang Asli volunteers using a recombinant antigen-based ELISA, previously shown to have sensitivity of ~90.0% in comparison to the microscopic agglutination test (MAT). Among the Orang Asli volunteers in this study, 60.7% had IgM against Leptospira and 57.9% were anti-Leptospira IgG positive. Of these seropositive individuals, 29.9% had both anti-Leptospira IgM and IgG antibodies. Age was found to be a significant predictor for exposure to Leptospira (P < 0.05) with the younger Orang Asli population more likely to be tested positive for anti-Leptospira IgM. The finding of high Leptospira exposure among the Orang Asli volunteers could be due to their socio-economic practices and dependency on the forest for their livelihood. The rapid and sensitive recombinant antigen-based ELISA used in the study, could possibly complement MAT for the epidemiological surveillance of leptospirosis, especially among the underserved populations
A Bilingual Child’s Two Writing System
No full textThe present study focusses on the writing evolution of a fourth-grade Japanese bilingual child who lives in Malaysia through the use of Howards' (2003) Two-Way Narrative Writing Assessment Rubric. This study examined the changes occurred in a bilingual child's journals written in Japanese and English, and to explore if there has been any interaction between his writing skills of the two languages. The data collection involved document analysis of his written journals. The document analysis of the written journals was based on word count, logography errors, and writing evolution (e.g., subject matter, sentence formation, and usage of adjectives). The findings of this study indicated that the participants' writing is grammatically correct in English, and both Japanese and English journals have a clear subject matter. However, further analysis on sentence formation and adjectives revealed that the participant has written poorly in his Japanese journals compared to his English journals. Thus, these findings point to the significance that schooling in two languages and early exposure of target language could have effectively supported the participant learning of writing skills. Through contrastive analysis, this study reflects on the successful evolution of bilingualism where it is possible for a bilingual child to acquire two different writing systems simultaneously
The ESL teachers' Willingness To communicate in English
No full textWillingness to communicate (WTC) as introduced by McCroskey and Bear (1985) has developed and been perceived by many as a critical field. Unfortunately, there is a noticeable gap in research on the willingness to communicate (WTC) in English among ESL teachers in the Malaysian context. This study aims to investigate the ESL teachers' willingness to communicate in English in terms of gender and school locations. The four constructs of communication in WTC are group discussions, interpersonal, public, and talking in meetings. Through both criterion and convenience sampling, 250 ESL teachers from twenty-five schools were chosen for this research. Survey questionnaire with a total of 20 items adopted from McCroskey (1992) was used as the data collection instrument. Findings reveal that ESL teachers' willingness to communicate in English is generally high and that the teachers were more willing to converse and exchange ideas orally in English during the meeting rather than in group or public. Female participants were significantly different in their overall willingness to communicate as they were more willing to communicate in groups and public. The within-group comparison also shows that school locations (urban and rural) affect ESL teachers' willingness to communicate in English. The findings also suggest that schools should encourage more ESL teachers to participate in activities such as debates, drama, public speaking, English language clubs/society, and empower them by providing professional development workshops or training
Purification of the recombinant enhanced green fluorescent protein from Escherichia coli using alcohol + salt aqueous two-phase systems
No full textThe enhanced green fluorescent protein (EGFP) is widely used as a marker in life science. Currently, purifications of the EGFP mostly involve chromatographic methods, which are multistep, time-consuming and costly. In the present study, the recombinant EGFP expressed in Escherichia coli was purified using an economic aqueous two-phase system (ATPS). Short-chain aliphatic alcohol and organic salt were chosen as the phase-forming components owing to their recyclability and biodegradability, respectively. The partition behaviour of EGFP was evaluated under the varying conditions of ATPS, including types and concentrations of phase-forming components, feedstock concentration, and pH. In an optimal primary 2-g ATPS comprising 1-propanol and tripotassium citrate, a high recovery of EGFP (i.e., 92.1%) was attained in the salt-rich bottom phase. To facilitate the easy recovery of purified EGFP, a secondary ATPS was used to back extract the EGFP to a new top ethanol-rich top phase, and the ethanol was removed from the purified EGFP via evaporation. The 1-propanol and ethanol used in the primary and secondary ATPSs (i.e. 20-g system) were successfully recycled in three successive rounds of EGFP purification, yielding the average EGFP purification factor of 11.34 and 75.7% of EGFP yield. The purification of EGFP using the two stages of alcohol + salt ATPSs is efficient in terms of operation time, cost and process scalability
Autoclaved Lime-Saline Soil Products: Reactivity Assessments and Effects of Quartz Sand
No full textOver the last few decades, the high growth rate in China's construction industry has increased the demand for building materials. Thus, the sustainable use and conservation of quality clay soil for brick production has attracted much attention in recent years. This paper investigates the technical feasibility of using saline soil as a raw material for the production of autoclaved lime-saline soil products. The reactivity of lime-saline soil under different autoclave temperatures (120, 150, and 175°C), pressures (0.10, 0.38, and 0.78 MPa), and times (1, 2, 3, and 6 h) was assessed. The experimental results indicate that saline soil's reactivity increased with increasing lime content as well as autoclave temperature, pressure, and reaction time. However, the reaction process seemed to be significant only for the first 2 h. The mixture proportions were varied to further examine the effects of sand sizes and their replacement content for saline soil on the properties of autoclaved specimens. It was observed that specimens containing 25-85% saline soil possessed compressive strength ranging from 17 to 36 MPa with relatively low water absorption (4.0-6.8%). Thermal analysis results indicate that tobermorite is responsible for the higher mechanical strength gain for the autoclaved specimens. The overall results have proved that it is feasible to produce an autoclaved lime-saline soil product with a lower environmental impact
Computational intelligence approaches for classification of medical data: State-of-the-art, future challenges and research directions
No full textThe explosive growth of data in volume, velocity and diversity that are produced by medical applications has contributed to abundance of big data. Current solutions for efficient data storage and management cannot fulfill the needs of heterogeneous data. Therefore, by applying computational intelligence (CI) approaches in medical data helps get better management, faster performance and higher level of accuracy in detection. This paper aims to investigate the state-of-the-art of computational intelligence approaches in medical data and to categorize the existing CI techniques, used in medical fields, as single and hybrid. In addition, the techniques and methodologies, their limitations and performances are presented in this study. The limitations are addressed as challenges to obtain a set of requirements for Computational Intelligence Medical Data (CIMD) in establishing an efficient CIMD architectural design. The results show that on the one hand Support Vector Machine (SVM) and Artificial Immune Recognition System (AIRS) as a single based computational intelligence approach were the best methods in medical applications. On the other hand, the hybridization of SVM with other methods such as SVM-Genetic Algorithm (SVM-GA), SVM-Artificial Immune System (SVM-AIS), SVM-AIRS and fuzzy support vector machine (FSVM) had great performances achieving better results in terms of accuracy, sensitivity and specificity
Biopolymeric electrolyte based on glycerolized methyl cellulose with NH4Br as proton source and potential application in EDLC
No full textIn the present work, biopolymer electrolyte films based on MC doped with NH4Br salt and plasticized with glycerol were prepared by solution casting method. Fourier transform infrared (FTIR) spectroscopy analysis confirms the interaction between MC, NH4Br, and glycerol. X-ray diffraction (XRD) explains that the enhancement of conductivity is affected by the degree of crystallinity. This result is verified by field emission scanning electron microscopy (FESEM). For unplasticized system, sample containing 25 wt% of NH4Br possesses the highest ionic conductivity of (1.89 ± 0.05) × 10−4 S cm−1. The addition of 30 wt% glycerol increases the conductivity value up to (1.67 ± 0.04) × 10−3 S cm−1. The conduction mechanism was best presented by the correlated barrier hopping (CBH) model. The linear sweep voltammetry (LSV) and cyclic voltammetry (CV) result confirms the suitability of the highest conducting electrolyte to be employed in the fabrication of electrochemical double layer capacitor (EDLC)
A New Routing Approach for Mobile Ad Hoc Systems Based on Fuzzy Petri Nets and Ant System
No full textMobile ad hoc network (commonly called MANET) comprises a large and relatively dense population of mobile units that move in any territory, and its only means of communication is the use of wireless interfaces without using pre-existing infrastructure or centralized administration. Moreover, routing should provide a strategy for sending data at any time between a pair of nodes (i.e., source and destination) across a network. However, the main problem is to determine an optimal routing of packets across the network. The main objective of the proposed protocol is to find the least-cost investment in nominal capacities that ensures the routing of nominal traffic and guarantees its survivability in case of any arc or node failure. In this context, the fuzzy synchronized Petri net is substantially adopted in the modeling of the routing and detection/decision functions that use a synchronized fuzzy transition approach, where the ant system is used to find a solution for the problem of uncertainty events in ad hoc networks. The obtained results show the effectiveness of the proposed synchronized Fuzzy Ant System (SynFAnt) protocol compared to four protocols. The SynFAnt routing protocol improves the packet delivery ratio, the throughput, the end-to-end delay, and the acceptance rate of the QoS flows