Displaying publications 1 - 20 of 1371 in total

Abstract:
Sort:
  1. Tan SY, Arshad H, Abdullah A
    PLoS ONE, 2019;14(1):e0207191.
    PMID: 30605474 DOI: 10.1371/journal.pone.0207191
    Mobile Augmented Reality (MAR) requires a descriptor that is robust to changes in viewing conditions in real time application. Many different descriptors had been proposed in the literature for example floating-point descriptors (SIFT and SURF) and binary descriptors (BRIEF, ORB, BRISK and FREAK). According to literature, floating-point descriptors are not suitable for real-time application because its operating speed does not satisfy real-time constraints. Binary descriptors have been developed with compact sizes and lower computation requirements. However, it is unclear which binary descriptors are more appropriate for MAR. Hence, a distinctive and efficient accuracy measurement of four state-of-the-art binary descriptors, namely, BRIEF, ORB, BRISK and FREAK were performed using the Mikolajczyk dataset and ALOI dataset to identify the most appropriate descriptor for MAR in terms of computation time and robustness to brightness, scale and rotation changes. The obtained results showed that FREAK is the most appropriate descriptor for MAR application as it able to produce an application that are efficient (shortest computation time) and robust towards scale, rotation and brightness changes.
  2. Mahadir Naidu B, Mohd Yusoff MF, Abdullah S, Musa KI, Yaacob NM, Mohamad MS, et al.
    PLoS ONE, 2019;14(1):e0207472.
    PMID: 30605462 DOI: 10.1371/journal.pone.0207472
    High blood pressure is a worldwide problem and major global health burden. Whether alone or combined with other metabolic diseases, high blood pressure increases the risk of cardiovascular disease. This study is a secondary data analysis from the National Health and Morbidity Survey 2015, a population-based study that was conducted nationwide in Malaysia using a multi-stage stratified cluster sampling design. A total of 15,738 adults ≥18-years-old were recruited into the study, which reports the prevalence of hypertension stages among adults in Malaysia using the JNC7 criteria and determinants of its severity. The overall prevalence of raised blood pressure was 66.8%, with 45.8% having prehypertension, 15.1% having Stage 1 hypertension, and 5.9% having Stage 2 hypertension. In the multivariate analysis, a higher likelihood of having prehypertension was observed among respondents with advancing age, males (OR = 2.74, 95% CI: 2.41-3.12), Malay ethnicity (OR = 1.21, 95% CI: 1.02-1.44), lower socioeconomic status, and excessive weight. The factors associated with clinical hypertension (Stages 1 and 2) were older age, rural residency (Stage 1 OR = 1.22, Stage 2 OR = 1.28), Malay ethnicity (Stage 2 OR = 1.64), diabetes (Stage 2 OR = 1.47), hypercholesterolemia (Stage 1 OR = 1.34, Stage 2 OR = 1.82), being overweight (Stage 1 OR = 2.86, Stage 2 OR = 3.44), obesity (Stage 1 OR = 9.01, Stage 2 OR = 13.72), and lower socioeconomic status. Almost 70% of Malaysian adults are at a risk of elevated blood pressure. The highest prevalence was in the prehypertension group, which clearly predicts a future incurable burden of the disease. Public health awareness, campaigns through mass and social media, and intervention in the work place should be a priority to control this epidemic.
  3. Muazu Musa R, P P Abdul Majeed A, Taha Z, Chang SW, Ab Nasir AF, Abdullah MR
    PLoS ONE, 2019;14(1):e0209638.
    PMID: 30605456 DOI: 10.1371/journal.pone.0209638
    k-nearest neighbour (k-NN) has been shown to be an effective learning algorithm for classification and prediction. However, the application of k-NN for prediction and classification in specific sport is still in its infancy. The present study classified and predicted high and low potential archers from a set of physical fitness variables trained on a variation of k-NN algorithms and logistic regression. 50 youth archers with the mean age and standard deviation of (17.0 ± 0.56) years drawn from various archery programmes completed a one end archery shooting score test. Standard fitness measurements of the handgrip, vertical jump, standing broad jump, static balance, upper muscle strength and the core muscle strength were conducted. Multiple linear regression was utilised to ascertain the significant variables that affect the shooting score. It was demonstrated from the analysis that core muscle strength and vertical jump were statistically significant. Hierarchical agglomerative cluster analysis (HACA) was used to cluster the archers based on the significant variables identified. k-NN model variations, i.e., fine, medium, coarse, cosine, cubic and weighted functions as well as logistic regression, were trained based on the significant performance variables. The HACA clustered the archers into high potential archers (HPA) and low potential archers (LPA). The weighted k-NN outperformed all the tested models at itdemonstrated reasonably good classification on the evaluated indicators with an accuracy of 82.5 ± 4.75% for the prediction of the HPA and the LPA. Moreover, the performance of the classifiers was further investigated against fresh data, which also indicates the efficacy of the weighted k-NN model. These findings could be valuable to coaches and sports managers to recognise high potential archers from a combination of the selected few physical fitness performance indicators identified which would subsequently save cost, time and energy for a talent identification programme.
  4. Mamman M, Hanapi ZM, Abdullah A, Muhammed A
    PLoS ONE, 2019;14(1):e0210310.
    PMID: 30682038 DOI: 10.1371/journal.pone.0210310
    The increasing demand for network applications, such as teleconferencing, multimedia messaging and mobile TV, which have diverse requirements, has resulted in the introduction of Long Term Evolution (LTE) by the Third Generation Partnership Project (3GPP). LTE networks implement resource allocation algorithms to distribute radio resource to satisfy the bandwidth and delay requirements of users. However, the scheduling algorithm problem of distributing radio resources to users is not well defined in the LTE standard and thus considerably affects transmission order. Furthermore, the existing radio resource algorithm suffers from performance degradation under prioritised conditions because of the minimum data rate used to determine the transmission order. In this work, a novel downlink resource allocation algorithm that uses quality of service (QoS) requirements and channel conditions to address performance degradation is proposed. The new algorithm is formulated as an optimisation problem where network resources are allocated according to users' priority, whereas the scheduling algorithm decides on the basis of users' channel status to satisfy the demands of QoS. Simulation is used to evaluate the performance of the proposed algorithm, and results demonstrate that it performs better than do all other algorithms according to the measured metrics.
  5. Teh LCL, Caddell R, Allison EH, Finkbeiner EM, Kittinger JN, Nakamura K, et al.
    PLoS ONE, 2019;14(1):e0210241.
    PMID: 30682056 DOI: 10.1371/journal.pone.0210241
    Sustainability standards for seafood mainly address environmental performance criteria and are less concerned with the welfare of fisheries workers who produce the seafood. Yet human rights violations such as slavery and human trafficking are widespread in fisheries around the world, and underscore the need for certification bodies and other seafood supply chain actors to improve social performance, in addition to addressing environmental challenges. Calls for socially responsible seafood have referenced human rights law and policy frameworks to shape the guiding principles of socially responsible seafood and to provide the legal machinery to implement these aspirations, but practical guidance on how to achieve this is lacking. To provide clarity on this challenge, we reviewed the literature concerning human rights in the seafood supply chain, and prepared an analysis of opportunities and challenges to implement socially responsible seafood through relevant human rights, legal and policy instruments. We observe that human rights laws are generally framed in favour of addressing violations of civil and political rights, but there remains considerable scope for applying economic, social and cultural (ESC) rights in this context. Other challenges include weakly defined ESC rights infringements, a lack of straightforward mechanisms to enforce human rights entitlements, and practical difficulties such as resources to support and secure rights. On the positive side, governments can draw on international instruments to inspire national policies and legislation to eliminate illegalities from the seafood supply chain. However, for socially responsible seafood principles to translate into tangible actions, these objectives must be rooted in clear legal obligations and be supported by sufficient national capacity and political will.
  6. Yeow TP, Aun ES, Hor CP, Lim SL, Khaw CH, Aziz NA
    PLoS ONE, 2019;14(1):e0211210.
    PMID: 30682116 DOI: 10.1371/journal.pone.0211210
    It remains widely perceived that early-onset Type 2 Diabetes (T2D) in children and adolescents is rare and clinically distinct from Type 1 Diabetes (T1D). We studied the challenges of classifying subtypes of early-onset diabetes using clinical features and biomarkers, and management of these patients. We reviewed retrospectively the record of patients < 25 years old who attended the diabetes clinic in Penang General Hospital, Malaysia between 1st December 2012 and 30th June 2015. We examined their clinical features, C-peptide and pancreatic autoantibodies. Comparisons were made between T1D and T2D for magnitude, demographics, metabolic status and complications. We studied 176 patients with a mean age of 20 ± 3.7 years, 43.2% had T1D, 13.6% had T2D, and 13.6% had mixed features of both. When tested, pancreatic autoantibodies were positive in 59.4% of the T1D. T2D presented two years later than T1D at 14.3 years, 20% were asymptomatic at presentation, and 50% required insulin supplementation despite fasting c-peptide of > 250 pmol/L. HbA1C of ≤ 8.0% (64 mmol/mol) was achieved in 30.3% of T1D, 58.3% of T2D on OAD and 16.7% of T2D on insulin. The T2D had greater cardiovascular risk with higher body mass index, more dyslipidaemia, higher blood pressure and earlier onset of nephropathy. The overlapping clinical features, variable autoimmunity, and beta-cell loss complicate classification of young diabetes. Pancreatic autoantibodies and C-peptide did not always predict diabetes subtypes nor respond to insulin. The poor metabolic control and high cardiovascular risk burden among the T2D highlight the need for population-based study and focused intervention.
  7. A Hamid MS, Sazlina SG
    PLoS ONE, 2019;14(1):e0209746.
    PMID: 30625165 DOI: 10.1371/journal.pone.0209746
    BACKGROUND: Childhood overweight and obesity has emerged as a major public health threat worldwide with challenges in its management. This review assessed the effectiveness of interventions for childhood overweight and obesity.

    METHODS: A systematic literature search was conducted using CINAHL, EMBASE, Ovid MEDLINE, PsycINFO and SPORTDiscus databases to retrieve articles published from 1st January 2000 to 31st December 2017. Randomised controlled trials (RCTs) and quasi-experimental studies comparing different strategies in managing overweight and obesity among schoolchildren (6 to 12 years of age) were included. The main outcomes of interest were reductions in weight related variables included anthropometry and body composition measurements. All variables were analysed using random effects meta-analyses.

    RESULTS: Fourteen studies were reviewed, 13 were RCTs and one was a quasi-experimental study. The risk of bias for randomisation was low risk for all of RCTs except for one, which was unclear. The risk of bias for randomisation was high for the quasi-experimental study. Most interventions incorporated lifestyle changes and behavioural strategies such as coping and problem solving skills with family involvement. The meta-analyses did not show significant effects of the intervention in reducing weight related outcomes when compared with controls.

    CONCLUSION: Meta-analyses of the selected studies did not show significant effects of the interventions on weight related outcomes among overweight and obese schoolchildren when compared with controls. The role of interdisciplinary team approaches with family involvement using behaviour and lifestyle strategies to curb obesity among schoolchildren is important.

  8. Nikitina L, Paidi R, Furuoka F
    PLoS ONE, 2019;14(1):e0210668.
    PMID: 30640925 DOI: 10.1371/journal.pone.0210668
    Quantitative applied linguistics research often takes place in restricted settings of an intact language classroom, workplace, phonetics laboratory or longitudinal sample. In such settings the samples tend to be small, which raises several methodological problems. The main aim of the current paper is to give a detailed explanation of methodological and practical implications inherent in a robust statistical method called bootstrapped quantile regression (BQR) analysis. Importantly for applied linguistics research, the BQR method could help to deal with methodological difficulties inherent in small sample studies. The current study employed a moderately small sample (N = 27) of students learning the Japanese language in a Malaysian public university. It examined the relationships between the students' language learning motivation (specifically, integrative orientation), the students' images or stereotypes about Japan and their global attitudes toward the target language country and its people. The findings indicated that there was a statistically significant relationship between the students' attitudes toward the target language country and their integrative orientation. In addition, these attitudes were found to be the most constant determinant of the integrative orientation. Besides the applied linguistics research, the BQR method can be used in a variety of the human sciences research where a sample size is small.
  9. Hariono M, Choi SB, Roslim RF, Nawi MS, Tan ML, Kamarulzaman EE, et al.
    PLoS ONE, 2019;14(1):e0210869.
    PMID: 30677071 DOI: 10.1371/journal.pone.0210869
    Dengue virus Type 2 (DENV-2) is predominant serotype causing major dengue epidemics. There are a number of studies carried out to find its effective antiviral, however to date, there is still no molecule either from peptide or small molecules released as a drug. The present study aims to identify small molecules inhibitor from National Cancer Institute database through virtual screening. One of the hits, D0713 (IC50 = 62 μM) bearing thioguanine scaffold was derivatised into 21 compounds and evaluated for DENV-2 NS2B/NS3 protease inhibitory activity. Compounds 18 and 21 demonstrated the most potent activity with IC50 of 0.38 μM and 16 μM, respectively. Molecular dynamics and MM/PBSA free energy of binding calculation were conducted to study the interaction mechanism of these compounds with the protease. The free energy of binding of 18 calculated by MM/PBSA is -16.10 kcal/mol compared to the known inhibitor, panduratin A (-11.27 kcal/mol), which corroborates well with the experimental observation. Results from molecular dynamics simulations also showed that both 18 and 21 bind in the active site and stabilised by the formation of hydrogen bonds with Asn174.
  10. Aldoghachi AF, Tor YS, Redzun SZ, Lokman KAB, Razaq NAA, Shahbudin AF, et al.
    PLoS ONE, 2019;14(1):e0211241.
    PMID: 30677092 DOI: 10.1371/journal.pone.0211241
    BACKGROUND: Brain-derived neurotrophic factor (BDNF) is a neurotrophin found in abundance in brain regions such as the hippocampus, cortex, cerebellum and basal forebrain. It has been associated with the risk of susceptibility to major depressive disorder (MDD). This study aimed to determine the association of three BDNF variants (rs6265, rs1048218 and rs1048220) with Malaysian MDD patients.

    METHODS: The correlation of these variants to the plasma BDNF level among Malaysian MDD patients was assessed. A total of 300 cases and 300 matched controls recruited from four public hospitals within the Klang Valley of Selangor State, Malaysia and matched for age, sex and ethnicity were screened for BDNF rs6265, rs1048218 and rs1048220 using high resolution melting (HRM).

    FINDINGS: BDNF rs1048218 and BDNF rs1048220 were monomorphic and were excluded from further analysis. The distribution of the alleles and genotypes for BDNF rs6265 was in Hardy-Weinberg equilibrium for the controls (p = 0.13) but was in Hardy Weinberg disequilibrium for the cases (p = 0.011). Findings from this study indicated that having BDNF rs6265 in the Malaysian population increase the odds of developing MDD by 2.05 folds (95% CI = 1.48-3.65). Plasma from 206 cases and 206 controls were randomly selected to measure the BDNF level using enzyme-linked immunosorbent assay (ELISA). A significant decrease in the plasma BDNF level of the cases as compared to controls (p<0.0001) was observed. However, there was no evidence of the effect of the rs6265 genotypes on the BDNF level indicating a possible role of other factors in modulating the BDNF level that warrants further investigation.

    CONCLUSION: The study indicated that having the BDNF rs6265 allele (A) increase the risk of developing MDD in the Malaysian population suggesting a possible role of BDNF in the etiology of the disorder.

  11. Jaddi NS, Abdullah S
    PLoS ONE, 2019;14(1):e0208308.
    PMID: 30608936 DOI: 10.1371/journal.pone.0208308
    Optimization of an artificial neural network model through the use of optimization algorithms is the common method employed to search for an optimum solution for a broad variety of real-world problems. One such optimization algorithm is the kidney-inspired algorithm (KA) which has recently been proposed in the literature. The algorithm mimics the four processes performed by the kidneys: filtration, reabsorption, secretion, and excretion. However, a human with reduced kidney function needs to undergo additional treatment to improve kidney performance. In the medical field, the glomerular filtration rate (GFR) test is used to check the health of kidneys. The test estimates the amount of blood that passes through the glomeruli each minute. In this paper, we mimic this kidney function test and the GFR result is used to select a suitable step to add to the basic KA process. This novel imitation is designed for both minimization and maximization problems. In the proposed method, depends on GFR test result which is less than 15 or falls between 15 and 60 or is more than 60 a particular action is performed. These additional processes are applied as required with the aim of improving exploration of the search space and increasing the likelihood of the KA finding the optimum solution. The proposed method is tested on test functions and its results are compared with those of the basic KA. Its performance on benchmark classification and time series prediction problems is also examined and compared with that of other available methods in the literature. In addition, the proposed method is applied to a real-world water quality prediction problem. The statistical analysis of all these applications showed that the proposed method had a ability to improve the optimization outcome.
  12. Contreras-Jodar A, Nayan NH, Hamzaoui S, Caja G, Salama AAK
    PLoS ONE, 2019;14(2):e0202457.
    PMID: 30735497 DOI: 10.1371/journal.pone.0202457
    The aim of the study is to identify the candidate biomarkers of heat stress (HS) in the urine of lactating dairy goats through the application of proton Nuclear Magnetic Resonance (1H NMR)-based metabolomic analysis. Dairy does (n = 16) in mid-lactation were submitted to thermal neutral (TN; indoors; 15 to 20°C; 40 to 45% humidity) or HS (climatic chamber; 37°C day, 30°C night; 40% humidity) conditions according to a crossover design (2 periods of 21 days). Thermophysiological traits and lactational performances were recorded and milk composition analyzed during each period. Urine samples were collected at day 15 of each period for 1H NMR spectroscopy analysis. Principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) assessment with cross validation were used to identify the goat urinary metabolome from the Human Metabolome Data Base. HS increased rectal temperature (1.2°C), respiratory rate (3.5-fold) and water intake (74%), but decreased feed intake (35%) and body weight (5%) of the lactating does. No differences were detected in milk yield, but HS decreased the milk contents of fat (9%), protein (16%) and lactose (5%). Metabolomics allowed separating TN and HS urinary clusters by PLS-DA. Most discriminating metabolites were hippurate and other phenylalanine (Phe) derivative compounds, which increased in HS vs. TN does. The greater excretion of these gut-derived toxic compounds indicated that HS induced a harmful gastrointestinal microbiota overgrowth, which should have sequestered aromatic amino acids for their metabolism and decreased the synthesis of neurotransmitters and thyroid hormones, with a negative impact on milk yield and composition. In conclusion, HS markedly changed the thermophysiological traits and lactational performances of dairy goats, which were translated into their urinary metabolomic profile through the presence of gut-derived toxic compounds. Hippurate and other Phe-derivative compounds are suggested as urinary biomarkers to detect heat-stressed dairy animals in practice.
  13. Zulkefli NN, Masdar MS, Wan Isahak WNR, Md Jahim J, Md Rejab SA, Chien Lye C
    PLoS ONE, 2019;14(2):e0211713.
    PMID: 30753209 DOI: 10.1371/journal.pone.0211713
    Adsorption technology has led to the development of promising techniques to purify biogas, i.e., biomethane or biohydrogen. Such techniques mainly depend on the adsorbent ability and operating parameters. This research focused on adsorption technology for upgrading biogas technique by developing a novel adsorbent. The commercial coconut shell activated carbon (CAC) and two types of gases (H2S/N2 and H2S/N2/CO2) were used. CAC was modified by copper sulfate (CuSO4), zinc acetate (ZnAc2), potassium hydroxide (KOH), potassium iodide (KI), and sodium carbonate (Na2CO3) on their surface to increase the selectivity of H2S removal. Commercial H2S adsorbents were soaked in 7 wt.% of impregnated solution for 30 min before drying at 120°C for 24 h. The synthesized adsorbent's physical and chemical properties, including surface morphology, porosity, and structures, were characterized by SEM-EDX, FTIR, XRD, TGA, and BET analyses. For real applications, the modified adsorbents were used in a real-time 0.85 L single-column adsorber unit. The operating parameters for the H2S adsorption in the adsorber unit varied in L/D ratio (0.5-2.5) and feed flow rate (1.5-5.5 L/min) where, also equivalent with a gas hourly space velocity, GHSV (212.4-780.0 hour-1) used. The performances of H2S adsorption were then compared with those of the best adsorbent that can be used for further investigation. Characterization results revealed that the impregnated solution homogeneously covered the adsorbent surface, morphology, and properties (i.e., crystallinity and surface area). BET analysis further shows that the modified adsorbents surface area decreased by up to 96%. Hence, ZnAc2-CAC clarify as the best adsorption capacity ranging within 1.3-1.7 mg H2S/g, whereby the studied extended to adsorption-desorption cycle.
  14. Sufyan M, Abd Rahim N, Tan C, Muhammad MA, Sheikh Raihan SR
    PLoS ONE, 2019;14(2):e0211642.
    PMID: 30763331 DOI: 10.1371/journal.pone.0211642
    The incessantly growing demand for electricity in today's world claims an efficient and reliable system of energy supply. Distributed energy resources such as diesel generators, wind energy and solar energy can be combined within a microgrid to provide energy to the consumers in a sustainable manner. In order to ensure more reliable and economical energy supply, battery storage system is integrated within the microgrid. In this article, operating cost of isolated microgrid is reduced by economic scheduling considering the optimal size of the battery. However, deep discharge shortens the lifetime of battery operation. Therefore, the real time battery operation cost is modeled considering the depth of discharge at each time interval. Moreover, the proposed economic scheduling with battery sizing is optimized using firefly algorithm (FA). The efficacy of FA is compared with other metaheuristic techniques in terms of performance measurement indices, which are cost of electricity and loss of power supply probability. The results show that the proposed technique reduces the cost of microgrid and attain optimal size of the battery.
  15. Rahman NA, Abu Hanifah S, Mobarak NN, Su'ait MS, Ahmad A, Shyuan LK, et al.
    PLoS ONE, 2019;14(2):e0212066.
    PMID: 30768616 DOI: 10.1371/journal.pone.0212066
    For the past decade, much attention was focused on polysaccharide natural resources for various purposes. Throughout the works, several efforts were reported to prepare new function of chitosan by chemical modifications for renewable energy, such as fuel cell application. This paper focuses on synthesis of the chitosan derivative, namely, O-nitrochitosan which was synthesized at various compositions of sodium hydroxide and reacted with nitric acid fume. Its potential as biopolymer electrolytes was studied. The substitution of nitro group was analyzed by using Attenuated Total Reflectance Fourier Transform Infra-Red (ATR-FTIR) analysis, Nuclear Magnetic Resonance (NMR) and Elemental Analysis (CHNS). The structure was characterized by X-ray Diffraction (XRD) and its thermal properties were examined by using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Whereas, the ionic conductivity of the samples was analyzed by electrochemical impedance spectroscopy (EIS). From the IR spectrum results, the nitro group peaks of O-nitrochitosan, positioned at 1646 and 1355 cm-1, were clearly seen for all pH media. At pH 6, O-nitrochitosan exhibited the highest degree of substitution at 0.74 when analyzed by CHNS analysis and NMR further proved that C-6 of glucosamine ring was shifted to the higher field. However, the thermal stability and glass transition temperatures were decreased with acidic condition. The highest ionic conductivity of O-nitrochitosan was obtained at ~10-6 cm-1. Overall, the electrochemical property of new O-nitrochitosan showed a good improvement as compared to chitosan and other chitosan derivatives. Hence, O-nitrochitosan is a promising biopolymer electrolyte and has the potential to be applied in electrochemical devices.
  16. Chong LC, Ganesan H, Yong CY, Tan WS, Ho KL
    PLoS ONE, 2019;14(2):e0211740.
    PMID: 30707739 DOI: 10.1371/journal.pone.0211740
    Macrobrachium rosenbergii nodavirus (MrNV) is the causative agent of white tail disease (WTD) which seriously impedes the production of the giant freshwater prawn and has a major economic impact. MrNV contains two segmented RNA molecules, which encode the RNA dependent RNA polymerase (RdRp) and the capsid protein (MrNV-CP) containing 371 amino acid residues. MrNV-CP comprises of the Shell (S) and the Protruding (P) domains, ranging from amino acid residues 1-252 and 253-371, respectively. The P-domain assembles into dimeric protruding spikes, and it is believed to be involved in host cell attachment and internalization. In this study, the recombinant P-domain of MrNV-CP was successfully cloned and expressed in Escherichia coli, purified with an immobilized metal affinity chromatography (IMAC) and size exclusion chromatography (SEC) up to ~90% purity. Characterization of the purified recombinant P-domain with SEC revealed that it formed dimers, and dynamic light scattering (DLS) analysis demonstrated that the hydrodynamic diameter of the dimers was ~6 nm. Circular dichroism (CD) analysis showed that the P-domain contained 67.9% of beta-sheets, but without alpha-helical structures. This is in good agreement with the cryo-electron microscopic analysis of MrNV which demonstrated that the P-domain contains only beta-stranded structures. Our findings of this study provide essential information for the production of the P-domain of MrNV-CP that will aid future studies particularly studies that will shed light on anti-viral drug discovery and provide an understanding of virus-host interactions and the viral pathogenicity.
  17. Rama Rao S, Liew TS, Yow YY, Ratnayeke S
    PLoS ONE, 2018;13(5):e0196582.
    PMID: 29734361 DOI: 10.1371/journal.pone.0196582
    Invasive snails in the genus Pomacea have spread across Southeast Asia including Peninsular Malaysia. Their effects on natural and agricultural wetlands are appreciable, but species-specific effects are less clear because of morphological similarity among the species. Our objective was to establish diagnostic characteristics of Pomacea species in Malaysia using genetic and morphological criteria. The mitochondrial COI gene of 52 adult snails from eight localities in Peninsular Malaysia was amplified, sequenced, and analysed to verify species and phylogenetic relationships. Shells were compared using geometric morphometric and covariance analyses. Two monophyletic taxa, P. canaliculata and P. maculata, occurred in our samples. The mean ratio of shell height: aperture height (P = 0.042) and shell height: shell width (P = 0.007) was smaller in P. maculata. P. maculata co-occurred with P. canaliculata in five localities, but samples from three localities contained only P. canaliculata. This study is the first to confirm the presence of two of the most invasive species of Pomacea in Peninsular Malaysia using a molecular technique. P. canaliculata appears to be the more widespread species. Despite statistical differences, both quantitative and qualitative morphological characteristics demonstrated much interspecific overlap and intraspecific variability; thus, shell morphology alone cannot reliably verify species identity. Molecular techniques for distinguishing between these two highly invasive Pomacea species are needed to understand their specific ecological niches and to develop effective protocols for their management.
  18. Imai N, Furukawa T, Tsujino R, Kitamura S, Yumoto T
    PLoS ONE, 2018;13(5):e0197391.
    PMID: 29763452 DOI: 10.1371/journal.pone.0197391
    While many tropical countries are experiencing rapid deforestation, some have experienced forest transition (FT) from net deforestation to net reforestation. Numerous studies have identified causative factors of FT, among which forest scarcity has been considered as a prerequisite for FT. In fact, in SE Asia, the Philippines, Thailand and Viet Nam, which experienced FT since 1990, exhibited a lower remaining forest area (30±8%) than the other five countries (68±6%, Cambodia, Indonesia, Laos, Malaysia, and Myanmar) where forest loss continues. In this study, we examined 1) the factors associated with forest scarcity, 2) the proximate and/or underlying factors that have driven forest area change, and 3) whether causative factors changed across FT phases (from deforestation to net forest gain) during 1980-2010 in the eight SE Asian countries. We used production of wood, food, and export-oriented food commodities as proximate causes and demographic, social, economic and environmental factors, as well as land-use efficiency, and wood and food trade as underlying causes that affect forest area change. Remaining forest area in 1990 was negatively correlated with population density and potential land area of lowland forests, while positively correlated with per capita wood production. This implies that countries rich in accessible and productive forests, and higher population pressures are the ones that have experienced forest scarcity, and eventually FT. Food production and agricultural input were negatively and positively correlated, respectively, with forest area change during 1980-2009. This indicates that more food production drives deforestation, but higher efficiency of agriculture is correlated with forest gain. We also found a U-shaped response of forest area change to social openness, suggesting that forest gain can be achieved in both open and closed countries, but deforestation might be accelerated in countries undergoing societal transition. These results indicate the importance of environmental, agricultural and social variables on forest area dynamics, and have important implications for predicting future tropical forest change.
  19. Zamli KZ, Din F, Ahmed BS, Bures M
    PLoS ONE, 2018;13(5):e0195675.
    PMID: 29771918 DOI: 10.1371/journal.pone.0195675
    The sine-cosine algorithm (SCA) is a new population-based meta-heuristic algorithm. In addition to exploiting sine and cosine functions to perform local and global searches (hence the name sine-cosine), the SCA introduces several random and adaptive parameters to facilitate the search process. Although it shows promising results, the search process of the SCA is vulnerable to local minima/maxima due to the adoption of a fixed switch probability and the bounded magnitude of the sine and cosine functions (from -1 to 1). In this paper, we propose a new hybrid Q-learning sine-cosine- based strategy, called the Q-learning sine-cosine algorithm (QLSCA). Within the QLSCA, we eliminate the switching probability. Instead, we rely on the Q-learning algorithm (based on the penalty and reward mechanism) to dynamically identify the best operation during runtime. Additionally, we integrate two new operations (Lévy flight motion and crossover) into the QLSCA to facilitate jumping out of local minima/maxima and enhance the solution diversity. To assess its performance, we adopt the QLSCA for the combinatorial test suite minimization problem. Experimental results reveal that the QLSCA is statistically superior with regard to test suite size reduction compared to recent state-of-the-art strategies, including the original SCA, the particle swarm test generator (PSTG), adaptive particle swarm optimization (APSO) and the cuckoo search strategy (CS) at the 95% confidence level. However, concerning the comparison with discrete particle swarm optimization (DPSO), there is no significant difference in performance at the 95% confidence level. On a positive note, the QLSCA statistically outperforms the DPSO in certain configurations at the 90% confidence level.
  20. Rahman F, Hassan M, Rosli R, Almousally I, Hanano A, Murphy DJ
    PLoS ONE, 2018;13(5):e0196669.
    PMID: 29771926 DOI: 10.1371/journal.pone.0196669
    Bioinformatics analyses of caleosin/peroxygenases (CLO/PXG) demonstrated that these genes are present in the vast majority of Viridiplantae taxa for which sequence data are available. Functionally active CLO/PXG proteins with roles in abiotic stress tolerance and lipid droplet storage are present in some Trebouxiophycean and Chlorophycean green algae but are absent from the small number of sequenced Prasinophyceaen genomes. CLO/PXG-like genes are expressed during dehydration stress in Charophyte algae, a sister clade of the land plants (Embryophyta). CLO/PXG-like sequences are also present in all of the >300 sequenced Embryophyte genomes, where some species contain as many as 10-12 genes that have arisen via selective gene duplication. Angiosperm genomes harbour at least one copy each of two distinct CLO/PX isoforms, termed H (high) and L (low), where H-forms contain an additional C-terminal motif of about 30-50 residues that is absent from L-forms. In contrast, species in other Viridiplantae taxa, including green algae, non-vascular plants, ferns and gymnosperms, contain only one (or occasionally both) of these isoforms per genome. Transcriptome and biochemical data show that CLO/PXG-like genes have complex patterns of developmental and tissue-specific expression. CLO/PXG proteins can associate with cytosolic lipid droplets and/or bilayer membranes. Many of the analysed isoforms also have peroxygenase activity and are involved in oxylipin metabolism. The distribution of CLO/PXG-like genes is consistent with an origin >1 billion years ago in at least two of the earliest diverging groups of the Viridiplantae, namely the Chlorophyta and the Streptophyta, after the Viridiplantae had already diverged from other Archaeplastidal groups such as the Rhodophyta and Glaucophyta. While algal CLO/PXGs have roles in lipid packaging and stress responses, the Embryophyte proteins have a much wider spectrum of roles and may have been instrumental in the colonisation of terrestrial habitats and the subsequent diversification as the major land flora.
Filters
Contact Us

Please provide feedback to Administrator (tengcl@gmail.com)

External Links