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Elucidating the biogeographical variation of the venom of Naja naja (spectacled cobra) from Pakistan through a venom-decomplexing proteomic study
No full textNaja naja is a medically important species that is distributed widely in South Asia. Its venom lethality and neutralization profile have been reported to vary markedly, but the understanding of this phenomenon has been limited without a comprehensive venom profile for the Pakistani N. naja. This study set to investigate the venom proteome of Pakistani N. naja applying reverse-phase HPLC, SDS-PAGE, mass spectrometry and data-mining approaches. The venom enzymatics and antigen binding activities were also studied. A total of 55 venom proteins comprising 11 toxin families were identified, with three-finger toxins (75.29%) being the predominant component, followed by phospholipase A2 (14.24%) and other proteins (< 5%). The enzyme activities of most of the venom components were also detected in this work. The high abundance of long neurotoxins (LNTX, 21.61%) in the Pakistani N. naja venom is varied from that reported for N. naja venoms from other geographical origins. The venom exhibited high immunoreactivity toward Naja kaouthia monovalent antivenom (NKMAV), which was raised against the LNTX-predominated heterologous Thai N. kaouthia venom. Together, the findings show that the Pakistani N. naja venom is predominated by LNTX, and this unique property correlates with its high lethality and effective neutralization by the heterologous NKMAV. Biological significance: This study reveals the compositional details of the venom proteome of Pakistani spectacled cobra (Naja naja). The protein subtypes, proteoforms, and relative abundances of individual proteins were comprehensively revealed in this study, following a venom decomplexing proteomic approach. The Pakistani cobra venom is unique among the rest of the N. naja venom composition reported thus far, as it contains a high abundance of alpha-neurotoxins (predominated by long neurotoxins); these are highly potent post-synaptic neuromuscular blockers that cause paralysis and are principal toxins that account for the high lethality of the venom (LD50 = 0.2 μg/g in mice). In contrast, previous reports showed that the N. naja venoms of India and Sri Lanka had a lower content of neurotoxins and a relatively higher value of LD50. The Pakistani cobra venom demonstrated sufficient immunoreactivity toward three antivenom products manufactured outside Pakistan (including the Indian product VINS), however the potency of antigen binding was the highest toward Naja kaouthia monovalent antivenom, a heterologous antivenom raised against a long neurotoxin-predominated venom of the Thai monocled cobra. From the practical standpoint, the findings indicate that the treatment of N. naja envenomation in Pakistan may be improved by the production of a locale-specific antivenom, in which the antivenom produced contains more antibodies that can target and react more specifically with the highly abundant lethal neurotoxins in the Pakistani N. naja venom
Spatio-temporal analysis of maximum Urban heat signature in urban forest: The case of University of Indonesia, Depok, West Java
No full textUrban temperature changes dynamically due to the rapid changes of urban land-use/land-cover. Urban forest is important to maintain the urban temperature at a pleasant level. Theoretically, vegetation could absorb more sun's radiation thus the urban forest can reduce maximum urban heat signature. This study assesses the capability of the urban forest in lowering the maximum temperature recorded in urban heat signature (UHS). UHS refers to a variety of heat characteristics based on different types of land-use/land-cover. The assessment was based on spatio-temporal analysis of surface temperature in the study area over a two-year period. Results showed a declining level of heat between built-up area (average of 30°C) and urban forest (average of 27°C) from 2013 to 2015 period. There is a difference of 4°C in maximum temperature between dense and sparse green areas, especially at 1pm. The presence of urban forest could reduce maximum urban heat signature
Influence of bed deposit in the prediction of incipient sediment motion in sewers using artificial neural networks
No full textThis study investigates the performance of artificial neural networks in predicting the incipient sediment motion in sewers. Two neural network algorithms, i.e. feed forward neural network (FFNN) and radial basis function (RBF), were employed to estimate the critical velocity over varying sediment thickness, median grain size and water depth. Empirical data from five studies were fed into the models and the performance of each model was scrutinized based on three performance criteria. Prediction from FFNN was found to give higher accuracy than values obtained from RBF. Analysis was also extended to observe the correlation between the predicted critical velocity (Formula presented.) with calculated critical velocity (Formula presented.) using five empirical equations developed using non-linear regression analysis. Prediction by FFNN proved to have the highest accuracy compared to the RBF and the values obtained through empirical equations described in this study
A highly sensitive multiplexed FBG pressure transducer based on natural rubber diaphragm and ultrathin aluminium sheet
No full textPressure measurement with a good sensitivity has always been a concern in most of the engineering applications and biomedical field. In this paper, a multiplexed FBG bonded on an ultrathin aluminium sheet which act as a cantilever deflected due to a deformation from a natural rubber based diaphragm has been proposed and studied. By using two gratings inscribed on a single optical fibre which senses the positive and negative strain has enhanced the sensitivity of the pressure transducer recorded at 329.56 pm/kPa or corresponding to 10.7893 kPa−1 across the range of 0 to 10 kPa with a good linearity of 99.76%. Furthermore, the thermal cross-sensitivity is compensated
Metabolomic profiles of tropical Chlorella and Parachlorella species in response to physiological changes during exponential and stationary growth phase
No full textChlorella species are known to be potential algal candidates for biodiesel production due to their ability to store high lipid content and their natural metabolic versatility. An understanding of physiology and metabolic capacity of indigenous Chlorella strains is potentially useful for future biodiesel production in the tropical environment. The primary aim of this study was to assess the photosynthetic performance, biochemical content and fatty acid composition of Chlorella and Parachlorella species grown and harvested during exponential (EX) and stationary (STA) growth phases in batch culture. Physiological data suggested that the cells responded to these conditions by initiating lipid accumulation when growing from EX to STA phase. An increase of lipid and saturated fatty acids (SFA) contents was observed in STA, although this trend was not consistent across the different strains of Chlorella and Parachlorella species. To gain further insights into metabolomic adaptation at different growth phases, metabolites were extracted from selected Chlorella and Parachlorella strains at EX and STA phase. These metabolic profiles were analysed resulting in identification of 74 metabolites. Metabolomic profiles of Parachlorella showed that there was an increase in recycling of amino acids and nucleic acids at STA phase. The metabolites associated with photosynthesis and chlorophyll biosynthesis were also repressed while carbon sources were channelled into lipid biosynthesis. Meanwhile, Chlorella species showed a similar response in carbon allocation for lipid accumulation with lesser influence on amino acid and chlorophyll degradation. Therefore, Chlorella and Parachlorella species exhibit different changes in metabolic responses at different growth phases, which may be the result of metabolic adaptations arising from their evolutionary plasticity. Overall, our results expand the current understanding of metabolomics of Chlorella and Parachlorella species and provide valuable insights into their lipid accumulation during different stages, which is important for optimization of lipid productivity for biodiesel production
Effect of Air and Argon Sintering Atmospheres on Properties and Hydrothermal Aging Resistance of Y-TZP Ceramics
No full textIn this work, we investigated the role of sintering atmosphere and temperature on low-temperature degradation of 3 mol.% yttria tetragonal zirconia polycrystals ceramics. Green compacts were prepared by die-pressing followed by cold isostatic pressing at 200 MPa. The green bodies were sintered between the temperature range of 1250 and 1500 °C in air and argon gas atmosphere. Sintered samples were tested to determine bulk density, Young’s modulus, Vickers hardness and fracture toughness. The results revealed that the mechanical properties of air-sintered samples were better than that of argon-sintered samples sintered at 1400 °C and below while the argon sintering marginally improves the fracture toughness and hardness when sintered at 1450 °C and above. FESEM images showed that the tetragonal grain size was similar when sintered in argon atmosphere. However, regardless of sintering atmosphere, grain growth was inevitable as the sintering temperature was increased. Hydrothermal aging test in superheated steam was performed in an autoclave at temperature of 180 °C and 10 bar pressure up to 12 h. Effect of aging on tetragonal-to-monoclinic phase transformation was measured by using x-ray diffraction. The phase transformation was found to be strongly influenced by the sintering temperature and sintering atmosphere. The sample sintered at 1500 °C in argon atmosphere exhibited rapid phase transformation compared to air atmosphere, while the samples sintered at or below 1400 °C in argon showed no phase transformation after 12-h exposure in steam environment
QuickCount ® : A novel automated software for rapid cell detection and quantification
No full textWe describe a novel automated cell detection and counting software, QuickCount ® (QC), designed for rapid quantification of cells. The Bland–Altman plot and intraclass correlation coefficient (ICC) analyses demonstrated strong agreement between cell counts from QC to manual counts (mean and SD: -3.3 ± 4.5; ICC = 0.95). QC has higher recall in comparison to ImageJ auto , CellProfiler and CellC and the precision of QC, ImageJ auto , CellProfiler and CellC are high and comparable. QC can precisely delineate and count single cells from images of different cell densities with precision and recall above 0.9. QC is unique as it is equipped with real-time preview while optimizing the parameters for accurate cell count and needs minimum hands-on time where hundreds of images can be analyzed automatically in a matter of milliseconds. In conclusion, QC offers a rapid, accurate and versatile solution for large-scale cell quantification and addresses the challenges often faced in cell biology research
Towards developing a valid scoring tool for bronchitis during flexible bronchoscopy
No full textBackground: A valid bronchoscopic scoring tool for bronchitis would be useful for clinical and research purposes as currently there are none in children. From 100 digitally recorded flexible bronchoscopies (FB), we related the various macroscopic features to airway neutrophil % to develop a FB-derived bronchitis score (BScoreexp). We aimed to develop a FB-derived bronchitis tool. Methods: FB recordings for six visualised features: secretions (amount and color) and mucosal appearance (erythema, pallor, ridging, oedema) based on pre-determined criteria on a pictorial chart were assessed by two physicians independently, blinded to the clinical history. These features were used to obtain various models of BScoreexp that were plotted against bronchoalveolar lavage (BAL) neutrophil % using a receiver operating characteristic (ROC) curve. Inter- and intra-rater agreement (weighted-kappa, K) were assessed from 30 FBs. Results: Using BAL neutrophilia of 20% to define inflammation, the highest area under ROC (aROC) of 0.71, 95%CI 0.61-0.82 was obtained by the giving three times weightage to secretion amount and color and adding it to erythema and oedema. Inter-rater K values for secretion amount (K = 0.87, 95%CI 0.73-1.0) and color (K = 0.86, 95%CI 0.69-1.0) were excellent. Respective intra-rater K were 0.95 (0.87-1.0) and 0.68 (0.47-0.89). Other inter-rater K ranged from 0.4 (erythema) to 0.64 (pallor). Conclusion: A repeatable FB-defined bronchitis scoring tool can be derived. However, a prospective study needs to be performed with larger numbers to further evaluate and validate these results
Assessing the ecological health status using macrobenthic communities of tropical coastal water
No full textThe relative contributions of natural and anthropogenic fluctuations are different in shaping habitat health status and natural benthic communities in tropical coastal water. Understanding responses of coastal benthic communities to these fluctuations are still equivocal and thus available data are inadequate. Here, multiple analytical approaches were used to address the significant risk factors and their impacts on coastal benthic habitat health through space and time. A total abundance of 1436 ± 612 individuals of 33 benthic species were counted and identified from 22 sampling stations across eight sampling periods over the two years of study. Bioassay results showed that the benthic community is moderately exposed to anthropogenic pollutants in Klang Strait coastal water. The results showed that there were no significant temporal changes of habitat health status and macrobenthic community structure; however, spatial changes were significant and synchronized with anthropogenic and natural fluctuations. This study demonstrates that Cd and Hg levels and sediment characteristics played the primary role in shaping the habitat health and macrobenthic assemblages, whereas the influence of other factors were insignificant
Cell Proliferation and DNA Repair Ability of Ganoderma neo-japonicum (Agaricomycetes): An Indigenous Medicinal Mushroom from Malaysia
No full textGanoderma neo-japonicum is an annual polypore that grows on decaying bamboo in the forests of Malaysia. The indigenous Temuan tribe uses this species as a medicinal mushroom to cure fever and epilepsy and to improve body strength. The potential use of G. neo-japonicum in genoprotection and DNA repair was established using a single-cell gel electrophoresis (comet) assay. The effects of the ethanol and hot aqueous extracts from wild and culti-vated basidiocarps, solid substrate-fermented (SSF) wheat grains, and mycelia via submerged culture on H2O2-damaged murine RAW264.7 macrophages were investigated. An ethanol extract from wild basidiocarps showed the most significant protective effect on murine RAW264.7 macrophages, followed by ethanol and hot water extracts of cultivated basidiocarps, and this effect was dose dependent. However, only the ethanol extracts from SSF and submerged culture showed significant protective effects compared with the control. As for DNA repair ability, only the ethanol extract from wild and cultivated basidiocarps showed significant results when compared with the negative control. The findings suggest the potential therapeutic use of G. neo-japonicum in genome protection and as a DNA repair stimulator