Inflammation and endothelial dysfunction are key components in atherogenesis. Should the status of these pro-atherogenesis factors be enhanced during prolonged confined space travel, specific countermeasures need to be instituted to prevent these processes to ensure safe outcome for astronauts during space expeditions. Six crew members were exposed to prolonged, confined isolation for 520 days. Standard exercise and diet regime were instituted throughout isolation phase. Age and gender-matched healthy, free living controls were recruited in parallel. Serial serum and whole blood were analysed for biomarkers of inflammation (hsCRP and IL-6) and endothelial activation (sICAM-1, sVCAM-1 and E-selectin). Flow-mediated dilatation (FMD) of the artery was performed following the standard protocols set by the International Brachial Artery Reactivity Task Force by trained personnel. There was decreased sVCAM-1 concentration in crew members compared to baseline. However, there was significant decrease in percentage dilatation from baseline in FMD of the brachial artery in the crew members. Percent change increment was observed in hsCRP while percent change reduction was seen in sVCAM-1. The enhanced inflammation and reduced endothelial function could possibly be attributed to the rigorous exercise instituted throughout the confinement period. Furthermore, possible haemoconcentration as a result of psychosocial stress and/ or exercise-induced physiological response could further explain elevations in hsCRP, and unlikely pathological. Furthermore, endothelial activation was attenuated during isolation, suggesting that the diet and exercise program instated throughout the period improved endothelial function.
The abuse of antibiotics usage in bird industry has resulted in the emerging antibiotic resistant Enterococci worldwide which has posed a threat clinically to human health. The present study was to screen and identify the potential virulence agents in antibiotic resistance E. faecalis in bird industry in Borneo. Enterococcus bacteria collected from the birds’ faeces and indoor air inside ten birdhouses were identified to species level and their antibiotic resistance was checked using antibiotic susceptibility discs. Specific primers using PCR assay were intended for the detection of four potential virulence genes (ace, AS, efaA, gelE). Out of the thirty-seven Enterococci faecal bacteria, the prevailing bacteria found were Enterococcus qallinacum (51%), Enterococcus faecalis (35%) and Enterococcus harae (8%). The airborne bacteria were reported as Enterococcus faecalis (5%) and Enterococcus qallinacum (1%). Twenty-seven percent of isolates were reported to have Multiple Antibiotic Resistance (MAR) index ≥ 0.2 with 9 distinct resistance patterns formed. E. faecalis showed higher resistance to vancomycin. Virulence genes were successfully reported in the 15 E. faecalis isolates. Sixty-seven percent of isolates were detected positive for four virulence genes, 27% possessed three (AS, efaA, gelE) genes and 6% possessed two (ace, AS) genes. Antibiotic resistance and virulence genes detection were significantly correlated. These virulence genes or antibiotic resistance genes were important in the pathogenesis of E. faecalis infections.
An ideal model organism for neurotoxicology research should meet several characteristics, such as low cost and amenable for high throughput testing. Javanese medaka (JM) has been widely used in the ecotoxicological studies related to the marine and freshwater environment, but rarely utilized for biomedical research. Therefore, in this study, the applicability of using JM in the neurotoxicology research was assessed using biochemical comparison with an established model organism, the zebrafish. Identification of biochemical changes due to the neurotoxic effects of ethanol and endosulfan was assessed using Fourier Transform Infrared (FTIR) analysis. Treatment with ethanol affected the level of lipids, proteins, glycogens and nucleic acids in the brain of JM. Meanwhile, treatment with endosulfan showed alteration in the level of lipids and nucleic acids. For the zebrafish, exposure to ethanol affected the level of protein, fatty acid and amino acid, and exposure to endosulfan induced alteration in the fatty acids, amino acids, nucleic acids and protein in the brain of zebrafish. The sensitive response of the JM toward chemicals exposure proved that it was a valuable model for neurotoxicology research. More studies need to be conducted to further develop JM as an ideal model organism for neurotoxicology research.
This paper presents parameters analysis for the estimated modal damping ratio using a new version of the automated enhanced frequency domain decomposition (AEFDD). The purpose of this study is to provide a better choice of a maximum number of points of time segments and modal assurance criterion (MAC) index number regarding to the variable level of system damping (low and high damped structure) and degree of freedom of the system. According current literature, frequency domain (FD) methods seem to have the problem with providing a correct identification of the modal damping ratio, since the correct estimate of modal damping is still an open problem and often leads to biased estimates. This technique is capable of providing consistent modal parameters estimation, particularly for modal frequencies and mode shapes. As a necessary fundamental condition, the algorithm has been assessed first from computed numerical responses according to random white noise, acting on different shear-type frame structures and corrupted with noise. Results indicate that reducing the value of natural frequencies and modal damping ratios of the modes under analysis demands longer time segments and a high value of the maximum number of points for adequate information on the decaying correlation functions when computing a modal damping ratio. In addition, the results also prove that the MAC index does not significantly affect the results for the low damped system. However, the use of a high MAC index value for the high damped system significantly introduces large error bound and it becomes worse, particularly for the higher modes, as the standard deviation of percentage error increases gradually. Furthermore, the use of a MAC index for a high number of points of time segments significantly increases the standard deviation of the percentage error.
Voice pathology analysis has been one of the useful tools in the diagnosis of the pathological voice, as the method is non-invasive, inexpensive, and can reduce the time required for the analysis. This paper investigates feature extraction based on the Dual-Tree Complex Wavelet Packet Transform (DT-CWPT) using energy and entropy measures tested with two classifiers, k-Nearest Neighbors (k-NN) and Support Vector Machine (SVM). Massachusetts Eye and Ear Infirmary (MEEI) voice disorders database and Saarbruecken Voice Database (SVD) were used. Five datasets of voice samples were used from these databases, including normal and abnormal samples, Cysts, Vocal Nodules, Polyp, and Paralysis vocal fold. To the best of the authors’ knowledge, very few studies were done on multiclass classifications using specific pathology database. File-based and frame-based investigation for two-class and multiclass were considered. In the two-class analysis using the DT-CWPT with entropies, the classification accuracy of 100% and 99.94% was achieved for MEEI and SVD database respectively. Meanwhile, the classification accuracy for multiclass analysis comprised of 99.48% for the MEEI database and 99.65% for SVD database. The experimental results using the proposed features provided promising accuracy to detect the presence of diseases in vocal fold.
Malaysia is the world’s third largest exporter of liquified natural gas and the second largest oil and natural gas producer in Southeast Asia, following Indonesia. The potential air pollutants released from the industry may affect the health of the population. The primary objective of this study was to determine the potential health risk among the population in the zone of impact. This was a comparative case study between controlled and uncontrolled emissions based on the air dispersion modelling. Hazard quotient (HQ) was used to assess non-carcinogenic risk, while lifetime cancer risk (LCR) was used to assess carcinogenic risk. All ambient air pollutant levels were within permissible levels and adhered to the standard. The HQ for hydrogen sulphide and benzene was less than one in all scenarios. The LCR for benzene was acceptable in all scenarios. Advanced pollution prevention equipment should be installed within the gas emission system to treat the final emission to meet prescribed permissible limits. Continuous ambient air monitoring and effective control measures should be practiced to ensure the sustainability of clean air. The health risk assessment showed no risk of developing malignancy and non-cancer disorder among the workers and general population living surround the petrochemical plants. This allows the development of the petroleum refinery plants to be continued.
Monitoring of land use change is crucial for sustainable resource management and development planning. Up-to-date land use change information is important to understand its pattern and identify the drivers. Remote sensing and geographic information system (GIS) have proven as a useful tool to measure and analyze land use changes. Recent advances in remote sensing technology with digital image processing provide unprecedented possibilities for detecting changes in land use over large areas, with less costs and processing time. Thus, the objective of this study was to assess the land use changes in upper Prek Thnot watershed in Cambodia from 2006 until 2018. Geospatial tools such as remote sensing and GIS were used to process and produce land use maps from Landsat 5 TM, Landsat 7 ETM+ and Landsat 8. The post-classification comparison was conducted for analysing the land use changes. Results show forest area was greatly decreased by 1,162.06 km2 (33.67%) which was converted to rubber plantation (10.55 km2 ), wood shrub (37.65 km2 ), agricultural land (1,099.71 km2 ), built-up area (17.76 km2 ), barren land (3.65 km2 ), and water body (14.69 km2 ). Agricultural land increased by 1,258.99 km2 (36.48%), while wood shrub declined by 161.88 km2 (4.69%). Rubber plantation, built-up area, barren land, and water bodies were increased by 10.55 km2 (0.31%), 33.64 km2 (0.97%), 4.87 km2 (0.14%) and 15.89 km2 (0.46%), respectively. The decrease of forest and wood shrub had resulted due to population growth (1.8% from 2008 to 2019) and land conversion for agricultural purposes. Hence, this study may provide vital information for wise sustainable watershed’s land management, especially for further study on the effect of land use change on runoff in this area.
Increased disposal of heavy metals, including lead (II) (Pb(II)) into the environment calls for a reliable and sustainable solution. In this study, nano-sized biochar from sago activated sludge was proposed for the removal of Pb(II). Sago activated sludge was pyrolysed in a tube furnace followed by a chemical activation to yield nano-sized particles ranging from 45 to 75 nm. The nano-sized biochar obtained was characterised and the influence of pH (2 – 10), initial Pb(II) concentration (1 – 5 mg/L), contact time (30 – 90 mins) and adsorbent dosage (0.1 – 0.5 g) was investigated in a batch adsorption study. Response surface methodology (RSM) approach with central composite design (CCD) was used as statistical tools to optimize the adsorption process by relating the mutual interactions among all studied variables. Characterisation of the prepared adsorbent showed that large surface area was observed on sludge activated carbon (78.863 m2 /g) compared with sludge biochar (8.044 m2 /g) and sludge biomass (1.303 m2 /g). The batch adsorption best fitted the Langmuir isotherm (maximum adsorption capacity, Q0 = 3.202 × 10-3 mg/g, R-squared value = 0.9308). The RSM indicated that the optimum Pb(II) removal (99.87%) was at 0.5 g of adsorbent, 5 mg/L initial concentration and 30 min contact time. This study is significant because utilisation of sago effluent will reduce sago manufacturing waste by conversion into a value-added product as adsorbent to adsorb Pb(II) in wastewater.
Continuous professional development (CPD) has gained prominence in the last decade to meet improved self-development and health care services among health professionals. Being practitioners serving clients in health care, therefore, necessitates the importance of the physiotherapist’s participation in activities of CPD. This paper aims to identify how physiotherapists view CPD, barriers to its progress and its impact on healthcare practice. This is a qualitative study with one-to-one interview sessions involving open-ended questions to facilitate free flow of idea that are rich with information. Twentytwo physiotherapist (17 females and 5 males) participated. Four main themes were generated following analysis: (i) comprehension of what is CPD (ii) outcome of CPD (iii) barriers to undertaking CPD and (iv) strategies to improve participation in CPD. Further sub-themes were generated from the themes suggestive of physiotherapists’ awareness and concerns related to CPD activities and problems encountered when embarking on CPD participation. In conclusion, physiotherapists should recognise the importance of participation in CPD activities either for self-development or to provide effective health care services. The main barrier to CPD activities that was identified was a support system that facilitates enhancement in such activities. This has major implication such as mandatory participation in CPD among staff and for managers to ensure that an effective mechanism is in place such as funding, schedule events and moral support.
Familial hypercholesterolaemia (FH) is a genetic disease that causes the elevation of lowdensity lipoprotein cholesterol (LDL-C), which subsequently leads to premature coronary heart disease (CHD). Features which have been reported to be associated with FH include lipids level, tendon xanthomata, and history of CHD. The Ordinal Logistic Regression model using the classification of FH patients with the Dutch Lipid Clinic Network Criteria (DLCN) as the dependent variable (where 1=Possible, 2=Probable, 3=Definite) was developed and evaluated for different types of link functions. The FH patients (n = 449) were recruited from health screening programmes conducted in hospitals and clinics in Malaysia from 2010 to 2018. Results indicate there is a significant association between FH categories with demographic factors (ethnicity and smoking) and physical symptoms (corneal arcus and xanthomata). The Ordinal Logistic Regression using Cauchit link function has lower Akaike Information Criterion (AIC) value, higher Nagelkerke’s R-Square and classification accuracy compared to Probit and Logit link function, diastolic blood pressure, corneal arcus and xanthomata were found to be significant covariates of FH.
Application of the Internet of things (IoT) for data collection in solar drying can be very efficient in collecting big data of drying parameters. There are many variables involved so it is hard to find a model to predict the moisture content of the food product during drying. In model building, interaction terms should be incorporated because they also contribute to the model. Eight selection criteria (8SC) is a very useful method in model building. This study applied ordinary least squares (OLS) regression and ridge regression with 8SC in model building to predict the moisture content of drying fish. A total of eighty models were considered in this study. One best model was chosen each from OLS regression and ridge regression. M78.7.3 with a total of eleven independent variables was the best OLS model after conducting multicollinearity and coefficient test. Next, the best ridge model M56.0.0 was obtained after the coefficient test. The mean absolute percentage error (MAPE) was used to measure the accuracy of the prediction model. For OLS model M78.7.3, the MAPE value was 15.7342. The MAPE value for ridge model M56.0.0 was 17.4054. From the MAPE value, OLS model M78.7.3 provided a better estimation than the ridge model M56.0.0. However, OLS model M78.7.3 violated the normality assumptions of residuals. This is highly caused by the outlier problem. So, due to non- normality of the residuals and presence of outliers in the dataset, ridge regression is preferred for the best forecast model.
The new emergence and re-emergence of arbovirus infections transmitted by Aedes mosquitoes have been spreading across Southeast Asia, Central Africa, United States, tropical Oceania and has become a major of public health concern. These arbovirus diseases were found to have a similar vector, symptoms, and environments. The situation is complex due to no specific vaccine or treatments being available for the diseases. Therefore, vector control is currently the best defense against arbovirus diseases, but with its own challenges such as the difficulty in controlling scattered breeding sites and biological behavior. Herein, we present a literature review of studies on current techniques proposed to combat dengue transmission that can fill a crucial gap in vector control programs, which is the inability of conventional control methods to eliminate and destroy cryptic breeding sites. In particular, we focused on the concept of autodissemination, which is a self-delivery technique by manipulating the behavior of mosquitoes, carrying the insecticide and disseminating it to cryptic breeding sites. This technique has shown promising results in some countries and can be considered as an additional tool in a vector control program. Therefore, we conducted Boolean searches in several electronic databases including Google Scholar, PubMed, SciELO and ScienceDirect to identify relevant published data regarding dengue and autodissemination techniques.
Graphene oxide (GO) is a reliable additive used to improve the wax crystal inhibition performance of pour point depressant (PPD). In understanding the lateral size effect on wax crystal inhibition, PPD emulsions containing graphene oxide of different lateral sizes were prepared. The parameters of pour point reduction (PPR) and dissipated wax crystallisation enthalpy were considered in the assessment of wax inhibition performance. PPR was measured using a pour point tester in accordance to ASTM D-97, while the enthalpy dissipation was evaluated via differential scanning calorimetry (DSC) under cooling cycle. The study revealed that the addition of GO lowered the wax crystallisation enthalpy, as indicated by the lesser amount of precipitated wax present in the model oil. The enthalpy underwent a decrease from 25.04 to 23.97 Jg-1 with decreasing GO lateral size. It is evident from the pour point test that the use of different GO lateral sizes significantly affects the wax inhibition, as verified through the highest PPR of 10o C displayed by the EJGO5 sample (with addition of the smallest lateral size of 1 µm). In short, manipulating the GO lateral size in sonicated samples boosted the PPR up to 100% compared to the unsonicated sample (EJGO1). Furthermore, smaller lateral size provides more nucleation site for wax co-crystallisation, hence preventing the neighbouring wax crystals from attaching and forming a looser crystal structure. The thermal characteristics of the PPD emulsions were also examined through DSC technique, which revealed that the emulsions thermal properties were unaffected by the addition of GO.
A mid-size combine harvester with 2.76 m reaping width and 103.53 hp engine output has been employed in grain corn production, especially by small-scale grain corn farmers. This study attempted to determine field performances of a typical mid-size combine harvester by measuring its effective field capacity (EFC), field efficiency (FE), fuel consumption (FC) and field machine index (FMI). Different types of energy inputs such as fuel, machinery, human, included direct, indirect, renewable and non-renewable energy involved in grain corn harvesting were also measured. The field measurements were carried out in 3 ha of grain corn farm, under similar field conditions using a typical mid-size combine harvester. The average values of EFC, FE, FC and FMI for the mid-size combine harvester were found to be 0.23 ha/h, 34.97%, 37.25 lit/ha and 0.91, respectively. The average equivalent energy values of fuel, machinery and human energy were 1780.70 MJ/ha, 587.73 MJ/ha and 8.53 MJ/ha, respectively. The average values of the direct and indirect energy were 1789.23 MJ/ha and 587.73 MJ/ha, respectively. The average values of renewable and non-renewable energy were recorded at 8.53 MJ/ha and 2368.42 MJ/ha, respectively. The mid-size combine harvester investigated in this study exhibited good field performance characteristic using a reasonable amount of energy consumption as compared to harvesting operation for other grain crops. From the results, it can be concluded that good practice in harvesting operation could improve field performance, and minimise operational costs and energy consumption.
The problems that arise in multitudinous fields often involve solving complex nonlinear ordinary differential equations (ODE), and it remains challenging since the actual solutions to these problems are hard to obtain. In this regard, the solution strategy with the formulation of Fourier series expansion, calculus of variation and metaheuristic algorithm, was introduced to determine the approximate solution of the nonlinear ODE. The nonlinear ODE was formulated as an optimization problem, specifically, the mothflame optimization (MFO) algorithm and flower pollination algorithm (FPA) were utilized to find the coefficients of the Fourier series. This paper aimed to determine the feasibility of the proposed method to solve the ODEs with different characteristics and compare the obtained results with other optimization algorithms. Moreover, the suitable number of terms (NT) of Fourier series were determined for different test problems for MFO and FPA. The quantitative analysis in terms of the generational distance (GD) metric demonstrated that the approximate solutions were reasonably accurate, with the low GD within the range of 1E-03 to 1E-05 for all test problems. The comparative analysis showed that the approximate performances of MFO and FPA were superior to or comparable with the genetic algorithm, particle swarm optimization and water cycle algorithm.
This work demonstrates the tunability of tapered single mode fiber (SMF) and tapered polarization maintaining fiber (PMF) filters based on fiber twisting method. One end of the tapered fiber was twisted from 0o until 100o using the Vytran Fiber Processing System. Observation on the spectral output shows that the fiber twisting technique is a viable option to impart tunability in tapered fibers with total shift of 15 and 10 nm, respectively for SMF and PMF. Better tunability is observed in the SMF filter due to its simple physical structure and more straightforward interferometry effect but a significantly higher extinction ratio is observed for the PMF filter. Both filters exhibited region of linear wavelength shift with corresponding R2 values of 0.9924 and 0.9294 for SMF and PMF. The simplicity and reliability of the filter may pave the way for the development of a practical and compact tunable all-fiber filter for laser systems.
High Leverage Points (HLPs) are outlying observations in the X -directions. It is very imperative to detect HLPs because the computed values of various estimates are affected by their presence. It is now evident that Diagnostic Robust Generalized Potential which is based on the Minimum Volume Ellipsoid (DRGP(MVE)) is capable of detecting multiple HLPs. However, it takes very long computational running times. Another diagnostic measure which is based on Index Set Equality denoted as DRGP(ISE) is put forward with the main aim of reducing its running time. Nonetheless, it is computationally not stable and still suffers from masking and swamping effects. Hence, in this paper, we propose another version of diagnostic measure which is based on Reweighted Fast Consistent and High Breakdown (RFCH) estimators. We call this measure Diagnostic Robust Generalized Potential based on RFCH and it is denoted by DRGP(RFCH). The results of simulation study and real data indicate that our proposed method outperformed the other two methods in term of having the least computing time, highest percentage of correct detection of HLPs and smallest percentage of swamping and masking effects compared to the DRGP(MVE) and DRGP (ISE).
The main objectives of this study were to introduce a bubble irrigation system, compare the wetting fronts created by the bubble and free-flow systems, and test the viability of a bubble irrigation system. Two laboratory experiments were conducted using 2D flow to measure the wetting fronts. The first experiment measured the free-flow infiltration using an inverted, open plastic bottle. The second experiment tested the bubble-flow technique using an inverted, closed plastic bottle (ICPB). The results showed that the bubble-flow system created a larger width of wetting fronts at the beginning of the infiltration and then expanded less than that of the free-flow system. In contrast, the infiltration depth of the wetting fronts created by the bubble-flow system was much lower than that of the free-flow system. In conclusion, the wetting front width and depth in the bubble-flow system were slightly smaller than those in the free-flow system. In addition, the wetting fronts created by the ICPB were not moved upwards significantly, which proves the ability of specific distribution of the bubble-flow system on the wetting fronts. Therefore, the bubble irrigation system can be used as an alternative for distributing the moisture content in soil profiles.
Food distribution and diversity is a significant factor that determines the habitat and site selection of avian species. Its effects on the health, reproduction, survival rate, diversity indices, population structure and home range of avian species. In wetland ecosystem, bird home range and population structure is influenced by richness and diversity of food resources and availability of suitable foraging sites. The aim of the study was to ascertain the food variety of Lesser Whistling Duck – Dendrocygna javanica in Paya Indah Wetland Reserve (PIWR). A scan method was employed from strategic places or blinds using a spotting scope and binocular to determine the food selection and density by Distance sampling point count method. Food items were categorised into the aquatic plants (AP), aquatic invertebrates (AIV), aquatic vertebrates (AV), terrestrial plants (TP), terrestrial vertebrates (TV) and terrestrial invertebrates (TIV). Distance analysis indicated that PIWR harboured 3.88 ± 0.00 birds per ha (n = 188 individuals). In addition, the results revealed that higher bird relative abundance of Lesser Whistling Duck concentrated in the shallow of Belibis lake that was rich in submerged and emergent vegetation (Eleocharis dulcis, Philydrum lanuginosum, Utricularia vulgaris, and Potamogeton perfoliatus). Kruskal–Wallis H test showed that food items were significantly different. Lesser Whistling Duck showed strong correlationship with AIV (r2 = 1.00, P < 0.05) and negative relationship with water TP (r2 = –0.061, P< 0.05). The regression model highlighted that Lesser Whistling Duck significantly preferred aquatic invertebrates, r2 = –0.686±0.68; P
Endless industrial development and growing society occasionally create an enormous volume of wastewater, which leads to some issues on wastewater treatment. Existing conventional screening processes have various limitations and drawbacks. Therefore, this study investigated the use of a combination of non-corrosive stainless steel wool and a permanent magnet to increase magnetic gradient, hence reducing suspended matter in sewage through turbidity test. An approach for optimizing the reduction of suspended matter through turbidity analysis was conducted using central composite design (CCD) under response surface methodology (RSM). Three critical independent variables, such as magnet strength, circulation time, and steel wool, and turbidity removal as the response, were further studied to analyze their interaction effects. As a result, an optimal value of turbidity removal was found at 90.3% under the specified optimum conditions of magnet strength of 245 mT, 116 g of non-corrosive stainless steel wool, and 16 h of circulation time. Statistical analysis had shown that the magnet strength, circulation time, and steel wool significantly affected the turbidity removal performance. Furthermore, design of experiment was significantly verified by a small range of error between predicted and actual data. Consequently, a higher gradient of magnetic separation was proven to effectively remove suspended matter using inexpensive non-corrosive stainless steel wool without using magnetic adsorbent. Thus, the suggested approach was found to be cost-effective and environmentally friendly for sewage treatment.