The Sharpened Romberg Test (SRT) is a test of balance commonly used in Diving Medicine. Interpretation of an abnormal test can be confounded by several factors. This study was conducted to further evaluate the usefulness of the SRT. In the first part of the study, naval and civilian volunteers in a Naval Base were recruited as subjects. The SRT scores were recorded in two separate trials; once in the morning (4 attempts) and once in the evening (4 attempts) to evaluate the effect of practice on the SRT. In the second part of the study immediate pre- and post-dive scores in a group of divers were measured to evaluate: (1) the effect of decompression; (2) the effect of the normal post-dive fatigue; and (3) the vestibular effect of swaying after a boat ride. Comparisons were also made between the distributions of the SRTs of the normal subjects and those of a retrospective group of DCI patients treated at the Slark Hyperbaric Unit, Royal New Zealand Navy Hospital (RNZNH), Auckland. The SRT was found to have an early learning effect. Second attempts were significantly better than the first (p<0.001) within the same trial. However this learning effect plateaued by the third and fourth attempts. No difference was found between trials (morning and evening). There was a post-dive decline in the scores of the first attempts only (p<0.05). Subsequent second to fourth attempts were not affected by diving. The practice effect is only evident between the first and second attempts within the same trial but not between trials. The pre- and post-dive data showed that the SRT was not affected by decompression, post-dive fatigue or the vestibular sensation of swaying that is commonly experienced after a boat ride. Comparison of the distributions between controls and DCI patients showed a bimodal pattern. Fifty-four percent (54%) of the DCI patients had 'normal' scores (60 seconds), while 14% had scores between 16-35 seconds and 32% scored less than 15 seconds. In contrast, 95% of the control groups had 'normal' scores while 5% scored between 16-35 seconds. Therefore, accepting a score of less than 40 seconds as being "abnormal" will give the SRT a sensitivity of 46%, specificity of 95% and predictive value of 82%.
Two cases of cerebral arterial gas embolism (CAGE) occurred after a decompression incident involving five maintenance crew during a cabin leakage system test of a Hercules C-130 aircraft. During the incident, the cabin pressure increased to 8 in Hg (203.2 mm Hg, 27 kPa) above atmospheric pressure causing intense pain in the ears of all the crew inside. The system was rapidly depressurized to ground level. After the incident, one of the crew reported chest discomfort and fatigue. The next morning, he developed a sensation of numbness in the left hand, with persistence of the earlier symptoms. A second crewmember, who only experienced earache and heaviness in the head after the incident, developed retrosternal chest discomfort, restlessness, fatigue and numbness in his left hand the next morning. Both were subsequently referred to a recompression facility 4 d after the incident. Examination by the Diving Medical Officer on duty recorded left-sided hemianesthesia and Grade II middle ear barotrauma as the only abnormalities in both cases. Chest X-rays did not reveal any extra-alveolar gas. Diagnoses of Static Neurological Decompression Illness were made and both patients recompressed on a RN 62 table. The first case recovered fully after two treatments, and the second case after one treatment. Magnetic resonance imaging (MRI) of the brain and bubble contrast echocardiography performed on the first case 6 mo after the incident were reported to be normal. The second case was lost to follow-up. Decompression illness (DCI) generally occurs in occupational groups such as compressed air workers, divers, aviators, and astronauts. This is believed to be the first report of DCI occurring among aircraft's ground maintenance crew.
A double-blind study was carried out to compare the efficacy and tolerability of nomifensine and amitriptyline in 17 Malaysian patients with moderate to severe depression. The two drugs did not differ with regard to antidepressant effect but nomifensine-treated subjects report fewer side-effects with no complaints of palpitations. Nomifensine also increases capacity for work and activity.
Hydrolysis of virgin coconut oil (VCO) had been carried out by using an immobilised lipase from Mucor miehei (Lipozyme) in a water-jacketed batch reactor. The kinetic of the hydrolysis was investigated by varying the parameters such as VCO concentration, enzyme loading, water content, and reaction temperature. It was found that VCO exhibited substrate inhibition at the concentration more than 40% (v/v). Lipozyme also achieved the highest production of free fatty acids, 4.56 mM at 1% (w/v) of enzyme loading. The optimum water content for VCO hydrolysis was 7% (v/v). A relatively high content of water was required because water was one of the reactants in the hydrolysis. The progress curve and the temperature profile of the enzymatic hydrolysis also showed that Lipozyme could be used for free fatty acid production at the temperature up to 50°C. However, the highest initial reaction rate and the highest yield of free fatty acid production were at 45 and 40°C, respectively. A 100 hours of initial reaction time has to be compensated in order to obtain the highest yield of free fatty acid production at 40°C.
A water extraction method has been used to extract plant proteins from the roots of Eurycoma longifolia harvested from Perak and Pahang, Malaysia. On the basis of the spectroscopic Bradford assay, Tongkat Ali Perak and Pahang contained 0.3868 and 0.9573 mg mL(-1) of crude protein, respectively. The crude proteins were separated by one dimensional 15% sodium dodecyl sulphate polyacrylamide gel electrophoresis into two (49.8 and 5.5 kD) and four (49.8, 24.7, 21.1 and 5.5 kD) protein spots for Tongkat Ali Perak and Pahang, respectively. Isoleucine was present in the highest concentration significantly. Both plant samples showed differences in the mineral and trace element profiles, but the minerals calcium, magnesium and potassium were present in the highest concentration. The highly concerned toxic metals such as arsenic and lead were not detected.
Termites from the genus Odontotermes are known to contain numerous species complexes that are difficult to tell apart morphologically or with mitochondrial DNA sequences. We developed markers for one such cryptic species complex, that is, Odontotermes srinakarinensis sp. nov. from Maxwell Hill Forest Reserve (Perak, Malaysia), and characterised them using a sample of 41 termite workers from three voucher samples from the same area. We then genotyped 150 termite individuals from 23 voucher samples/colonies of this species complex from several sites in Peninsular Malaysia. We analysed their population by constructing dendograms from the proportion of shared-alleles between individuals and genetic distances between colonies; additionally, we examined the Bayesian clustering pattern of their genotype data. All methods of analysis indicated that there were two distinct clusters within our data set. After the morphologies of specimens from each cluster were reexamined, we were able to separate the two species morphologically and found that a single diagnostic character found on the mandibles of its soldiers could be used to separate the two species quite accurately. The additional species in the clade was identified as Odontotermes denticulatus after it was matched to type specimens at the NHM London and Cambridge Museum of Zoology.
Pollen flow and population genetic structure among 30 potentially flowering individuals of Neobalanocarpus heimii, a tropical emergent tree, were investigated in a lowland tropical rainforest of Malaysia using microsatellite polymorphism. The 248 offspring in the vicinity of five reproductive trees of the 30 potentially flowering trees were used in paternity analysis for pollen-flow study. Four primer pairs, developed in different species of dipterocarps, were adopted to detect microsatellite polymorphism. Based upon microsatellite polymorphism, pollen flow and seed migration were detected. Pollen-flow events of more than 400 m were observed directly, based on paternity analysis in the study plot. The estimated average mating distance of the five reproductive trees was 524 m. This result suggests that reproduction of this species is mediated by a long-distance pollinator. The haplotypes of some offspring were not compatible with the nearest reproductive tree. Thus, the results suggest that some seeds are dispersed by a seed dispersal vector. Investigation of genetic structure showed significant and negative correlation of genetic relatedness and spatial distances between the 30 potentially flowering trees, but this correlation was weak. We suggest that long-distance gene flow and seed migration are responsible for the poorly developed genetic structure of this species.
Anaerobic digestion (AD) serves as a promising alternative for waste treatment and a potential solution to improve the energy supply security. The feasibility of AD has been proven in some of the technologically and agriculturally advanced countries. However, development is still needed for worldwide implementation, especially for AD process dealing with municipal solid waste (MSW). This paper reviews various approaches and stages in the AD of MSW, which used to optimise the biogas production and quality. The assessed stages include pre-treatment, digestion process, post-treatment as well as the waste collection and transportation. The latest approaches and integrated system to improve the AD process are also presented. The stages were assessed in a relatively quantitative manner. The range of energy requirement, carbon emission footprint and the percentage of enhancement are summarised. Thermal hydrolysis pre-treatment is identified to be less suitable for MSW (-5% to +15.4% enhancement), unless conducted in the two-phase AD system. Microwave pre-treatment shows consistent performance in elevating the biogas production of MSW, but the energy consumption (114.24-8,040 kWeh t-1) and carbon emission footprint (59.93-4,217.78 kg CO2 t-1 waste) are relatively high. Chemical (∼0.43 kWeh m-3) and membrane-based (∼0.45 kWeh m-3) post-treatments are suggested to be a lower energy consumption approach for upgrading the biogas. The feasibility in terms of cost (scale up) and other environmental impacts (non-CO2 footprint) needs to be further assessed. This study provides an overview to facilitate further development and extended implementation of AD.
Lignocellulosic waste (LW) is abundant in availability and is one of the suitable substrates for anaerobic digestion (AD). However, it is a complex solid substrate matrix that hinders the hydrolysis stage of anaerobic digestion. This study assessed various pre-treatment and post-treatments of lignocellulosic waste for anaerobic digestion benefiting from advanced P-graph and GaBi software (Thinkstep, Germany) from the perspective of cost and environmental performances (global warming potential, human toxicity, ozone depletion potential, particulate matter, photochemical oxidant creation, acidification and eutrophication potential). CaO pre-treatment (P4), H2S removal with membrane separation post-treatment (HSR MS) and without the composting of digestate is identified as the cost-optimal pathway. The biological (P7- Enzyme, P8- Microbial Consortium) and physical (P1- Grinding, P2- Steam Explosion, P3- Water Vapour) pre-treatments alternatives have lower environmental impacts than chemical pre-treatments (P4- CaO, P5- NaOH, P6- H2SO4) however they are not part of the near cost optimal solutions. For post-treatment, the near cost optimal alternatives are H2S removal with organic physical scrubbing (HSR OPS) and H2S removal with amine scrubbing (HSR AS). HSR AS has a better performance in the overall environmental impacts followed by HSR MS and HSR OPS. In general, the suggested cost-optimal solution is still having relatively lower environmental impacts and feasible for implementation (cost effective). There is very complicated to find a universal AD solution. Different scenarios (the type of substrate, the scale, product demand, policies) have different constraints and consequently solutions. The trade-offs between cost and environment performances should be a future extension of this work.
This review covers the recent advancements in selected emerging energy sectors, emphasising carbon emission neutrality and energy sustainability in the post-COVID-19 era. It benefited from the latest development reported in the Virtual Special Issue of ENERGY dedicated to the 6th International Conference on Low Carbon Asia and Beyond (ICLCA'20) and the 4th Sustainable Process Integration Laboratory Scientific Conference (SPIL'20). As nations bind together to tackle global climate change, one of the urgent needs is the energy sector's transition from fossil-fuel reliant to a more sustainable carbon-free solution. Recent progress shows that advancement in energy efficiency modelling of components and energy systems has greatly facilitated the development of more complex and efficient energy systems. The scope of energy system modelling can be based on temporal, spatial and technical resolutions. The emergence of novel materials such as MXene, metal-organic framework and flexible phase change materials have shown promising energy conversion efficiency. The integration of the internet of things (IoT) with an energy storage system and renewable energy supplies has led to the development of a smart energy system that effectively connects the power producer and end-users, thereby allowing more efficient management of energy flow and consumption. The future smart energy system has been redefined to include all energy sectors via a cross-sectoral integration approach, paving the way for the greater utilization of renewable energy. This review highlights that energy system efficiency and sustainability can be improved via innovations in smart energy systems, novel energy materials and low carbon technologies. Their impacts on the environment, resource availability and social well-being need to be holistically considered and supported by diverse solutions, in alignment with the sustainable development goal of Affordable and Clean Energy (SDG 7) and other related SDGs (1, 8, 9, 11,13,15 and 17), as put forth by the United Nations.
This study was carried out to investigate the physicochemical properties of compost from oil palm empty fruit bunches (EFB) inoculated with effective microorganisms (EM∙1™). The duration of microbial-assisted composting was shorter (∼7 days) than control samples (2 months) in a laboratory scale (2 kg) experiment. The temperature profile of EFB compost fluctuated between 26 and 52 °C without the presence of consistent thermophilic phase. The pH of compost changed from weak acidic (pH ∼5) to mild alkaline (pH ∼8) because of the formation of nitrogenous ions such as ammonium (NH4 (+)), nitrite (NO2 (-)), and nitrate (NO3 (-)) from organic substances during mineralization. The pH of the microbial-treated compost was less than 8.5 which is important to prevent the loss of nitrogen as ammonia gas in a strong alkaline condition. Similarly, carbon mineralization could be determined by measuring CO2 emission. The microbial-treated compost could maintain longer period (∼13 days) of high CO2 emission resulted from high microbial activity and reached the threshold value (120 mg CO2-C kg(-1) day(-1)) for compost maturity earlier (7 days). Microbial-treated compost slightly improved the content of minerals such as Mg, K, Ca, and B, as well as key metabolite, 5-aminolevulinic acid for plant growth at the maturity stage of compost. Graphical Abstract Microbial-assisted composting on empty fruit bunches.
Both total phenolic content (TPC) and total flavonoid content (TFC) of Labisia pumila extracts were determined spectrophotometrically. L. pumila leaves extracted in 60% methanol (MeOH) were fractionated on C18 cartridge and the antioxidant property of each fraction was determined by measuring free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity. The 40% MeOH fraction exhibited the highest scavenging activity. Nine flavonols (quercetin, myricetin and kaempferol), two flavanols (catechin and epigallocatechin) and nine phenolic acids were identified from this active fraction by UPLC-ESI-MS/MS, and confirmed by comparison with the mass spectra of standard aglycones, theoretical fragments generated from MS Fragmenter software, and literature values.
Microsatellite markers were developed for Johannesteijsmannia lanceolata to assess the genetic diversity and mating system of this alarmingly endangered species.
Microsatellite markers of an important medicinal plant, Eurycoma longifolia (Simaroubaceae), were developed for DNA profiling and genetic diversity studies.
Simple sequence repeats (SSRs) derived from expressed sequence tags (ESTs) are valuable markers because they represent transcribed regions and often transferable to related taxa. Here, we report the development and characterization of EST-SSRs from Shorea leprosula. Fifty-four sequences containing SSRs were identified in 2003 unigenes assembled from 3159 ESTs. Twenty-four EST-SSRs were developed, of which four gave multiple amplifications, five were found to be monomorphic and 15 showed polymorphism, with allele numbers ranging from two to 17 in a single Pasoh Forest Reserve population of 24 individuals. The observed and expected heterozygosities ranged from 0.05 to 0.91 and from 0.16 to 0.93, respectively. Cross-species transferability of the 15 loci to 36 species within Dipterocarpaceae revealed between four and 14 loci that gave positive amplification and 10 loci were found to be transferable to more than 15 species.
A field survey of Virgin Jungle Reserve (VJR) compartments in Peninsular Malaysia allowed us to identify six populations of Intsia palembanica for this study. These were Pasoh Forest Reserve (FR) (Pasoh), Sungai Lalang FR (Lalang), Bukit Lagong FR (Lagong), Bubu FR (Bubu), Bukit Kinta FR (Kinta), and Bukit Perangin FR (Perangin). About 40 adult individuals were sampled in each population. In addition, progeny arrays were collected from nine mother plants at Lagong for a mating system study. A total of nine allozymes, encoded by 14 putative gene loci, were consistently resolved in I. palembanica. The mating system study showed that the species exhibited a mixed-mating system, with multilocus outcrossing rate of 0.766. The levels of diversity were comparably high (mean number of alleles per polymorphic locus = 2.4, mean effective number of alleles per polymorphic locus = 1.64, and mean expected heterozygosity (H(e)) = 0.242), and the majority of the diversity was partitioned within population (G(ST) = 0.040 and F(ST) = 0.048). Significant levels of inbreeding were detected in Bubu and Perangin. Probability tests of recent effective population size reduction using the Infinite Allele Model showed the occurrence of genetic bottlenecks on Lalang and Kinta. Two genetically unique populations (Pasoh and Perangin) were inferred using jackknife analysis. By using the neutral mutation rates, effective population size (N(e)) to maintain the H(e) was 80-800 000 individuals. A simulation study based on pooled samples, however, circumscribed the N(e) to 200 and 210 individuals. Implications of the study for managing the species and the VJRs are discussed.
Tectonic movements, climatic oscillations, and marine transgressions during the Cenozoic have had a dramatic effect on the biota of the tropical rain forest. This study aims to reveal the phylogeography and evolutionary history of a Peninsular Malaysian endemic tropical timber species, Neobalanocarpus heimii (Dipterocarpaceae). A total of 32 natural populations of N. heimii, with 8 samples from each population were investigated. Fifteen haplotypes were identified from five noncoding chloroplast DNA (cpDNA) regions. Overall, two major genealogical cpDNA lineages of N. heimii were elucidated: a widespread southern and a northern region. The species is predicted to have survived in multiple refugia during climatic oscillations: the northwestern region (R1), the northeastern region (R2), and the southern region (R3). These putative glacial refugia exhibited higher levels of genetic diversity, population differentiation, and the presence of unique haplotypes. Recolonization of refugia R1 and R2 could have first expanded into the northern region and migrated both northeastwards and northwestwards. Meanwhile, recolonization of N. heimii throughout the southern region could have commenced from refugia R3 and migrated toward the northeast and northwest, respectively. The populations of Tersang, Pasir Raja, and Rotan Tunggal exhibited remarkably high haplotype diversity, which could have been the contact zones that have received an admixture of gene pools from the northerly and also southerly regions. As a whole, the populations of N. heimii derived from glacial refugia and contact zones should be considered in the conservation strategies in order to safeguard the long-term survival of the species.