Myogenic tone is the response of the vascular smooth muscle to an increase in intraluminal pressure with vasoconstriction and with vasodilation when the pressure is decreased. Such myogenic tone contributes a level of physiological basal tone in response to neurohumoral stimuli. In spite of myogenic tone discovery by Sir William Bayliss 100 years ago, questions still remain regarding the underlying signaling mechanism of the myogenic response. Studies have shown that increased intraluminal pressure or wall tension leads to membrane depolarization, voltage-operated calcium channel (VOCC), stretch-activated cation (SAC) channels, extracelullar matrix (ECM) and actin cytoskeleton. Recently, evidence has shown a potential role for reactive oxygen species (ROS) as a key signalling mediator in the genesis of myogenic tone. The identification of the primary mechanosensors in the initiation of pressure-dependent myogenic tone is essential as these components could be potential therapeutical targets in the future.
Enamel demineralization is associated with decrease in saliva pH due to fermentation of sugar by oral commensal. Thus, exploring the changing pattern of saliva pH is meaningful in dental caries prevention. The aim of this study was to compare the changing pattern of saliva pH after consuming different types of sweeteners (sucrose and maltitol). Methods: It was a case-control study involving 14 male patients attending IIUM dental clinic who were selected with the intention of getting seven patients with high caries risk ( DMFT ≥6) and seven patients with low caries risk (DMFT ≤3) with initial saliva pH interval of 6.5 to7.5. Patients were asked to consume snacks containing 8 gram sucrose and 8 gram maltitol as sweeteners. The changing pH values of the saliva were measured by Waterproof pHTestr 10BNC (Oakton, Vernon Hills, USA) seven times consecutively at 0 (before snack consumption), and at 5, 10, 15, 20, 30 and 60 minutes after snack consumption. The pH values of saliva of patients with low and high caries risk after consuming sucrose and maltitol were statistically analized by using Anova and Tukey-HSD tests at α = 0.05. Result: There were significant differences in saliva pH changes between low-risk group and high-risk group after consuming sucrose and maltitol. Conclusion: The changing patterns of saliva pH in high-risk patients were lower than those of low-risk patients after consuming two types of snacks containing sucrose and maltitol.
The production of ethanol, from glucose in batch and fed batch culture, was investigated. In the fed batch culture, the glucose feeding was added into the culture at 16th hour of fermentation. The effects of different glucose concentration feeding rates on ethanol fermentation were investigated for fed batch culture. The 2gL-1hr-1 glucose concentration feeding rate was found to give higher ethanol yield (2.47 g ethanol g glucose-1), with respect to substrate consumed as compared to 8 gL-1hr-1 (0.23 g ethanol g glucose-1) and 4 gL-1hr-1 (0.20 g ethanol g glucose-1). The ethanol yield with respect to substrate consumed obtained in batch culture was 0.81 g ethanol g glucose-1. The fed batch culture at 2 gL-1hr-1 glucose concentration feeding rate was proven to be a better fermentation system than the batch culture. The specific growth rate, specific glucose consumption rate and specific ethanol production rate for the fed batch fermentation, at 2 gL-1hr-1 glucose concentration feeding rate, were 0.065 hr-1, 1.20 hr-1 and 0.0009 hr-1, respectively.
Many studies have shown that probiotic strains added to a number of probiotic products are not compatible to that of
claimed. It is thus of note to validate probiotic strains added to probiotic products. In this study, three probiotic drinks,
A, B and C, were cultured on MRS agar and the number of bacterial colonies was enumerated. The bacterial counts
recovered from A (9.3 ± 6.9 log CFU/ml) and C (9.0 ± 6.9 log CFU/ml) were signifi cantly higher than B (5.2 ± 3.5 log
CFU/ml) and achieved the minimal amount recommended for probiotic bacteria. All of the isolates appeared as gram
positive rods microscopically and were proven to be catalase negative. However, there were only A1, A2, B4 and C1 that
were highly tolerant to the gastrointestinal pH 3 to 6. The four isolates produced and secreted antimicrobial substances
which inhibited the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). C1 showed the greatest
growth inhibition by forming 17.50-mm and 17.85-mm inhibition zones against E. coli and S. aureus, respectively. The
16s rDNA sequencing and phylogenetic analysis were performed to further identify the twelve isolates. The twelve isolates
were found to be Lactobacillus (L.), particularly L. casei and L. paracasei. However, the bacteria isolated from drink B
were incompatible to the labelled ones. In conclusion, probiotic drinks are possible to contain different bacterial counts
and probiotic strains from the labelled ones. These differences might affect health benefi ts rendered by probiotic strains
to consumers.
Elevated temperature affects marine benthic algae by reducing growth and limits the transport of electron or carbon fixation which may reduce the ability of the cell to use light. This resulting excess light energy may cause photoinhibition. In this study, the photosystem II of the benthic microalgal communities from Casey, eastern Antarctic were relatively unaffected by significant changes in temperatures up to 8ºC, along with high PAR level (450 μmol photons m–2 s–1). Similarly, the community was able to photosynthesize as the temperature was reduced to –5ºC. Recovery from saturating and photoinhibiting irradiances was not significantly influenced by temperatures at both –5ºC and 8ºC. These responses were consistent with those recorded by past experiments on Antarctic benthic diatoms and temperate diatoms which showed that climate change did not have a significant impact on the ability of benthic microalgae to recover from photoinhibitory temperature stress.
Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use of peptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study of biological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries of existing disciplines. Many self-assembling systems are range from bi- and tri-block copolymers to DNA structures as well as simple and complex proteins and peptides. The ultimate goal is to harness molecular self-assembly such that design and control of bottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes of life and non-life science applications. Such aspirations can be achieved through understanding the fundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.
Cassava starch was used as feedstock for production of bioethanol by Saccharomyces cerevisiae. The cassava starch was hydrolyzed using commercial α-amylase and glucoamylase enzymes followed by a batch ethanol fermentation process using saccharified starch slurry. By using 110 g/L of reducing sugar from saccharified starch slurry, the ethanol yield was promising with maximum ethanol concentration of 20.6 g/L recorded after 55 hours of cultivation process. Three different models - the Logistic model, Luedeking-Piret-like equation and Gompertz equation - were used to characterize and explain the cell growth, reducing sugar consumption and production formation, respectively. The kinetic parameters were estimated by fitting the experimental data to the proposed models using non-linear regression analysis. The correlation coefficient r2 values for the Logistic model, Luedeking-Piret-like equation and the Gompertz equation were 0.994, 0.996 and 0.990, respectively. The high correlation coefficient values indicate that the proposed models were able to describe the ethanol fermentation process.
The term Developing Nations has to be used with caution as it had traditionally included a wide array of countries outside the developed world of North America, Western Europe and Japan (and a few other countries such as Australia and South Africa). The characteristics which defined these “emerging markets” were a Gross National Product (GNP) per capita which was below that of the developed economies, the potential for market growth and an environment with continued economic and political instability. However, as many of these countries have grown at different rates and have economic and other drivers which are very different and disparate, definitions of this sector have become more fragmented. (Copied from article).
The beneficial impact of the differential biofeedback intervention technique on modification in autonomic competence, as well as the ultimate impact on bilateral shooting ability, were studied on young and competitive male soccer players. A total of 45 young high-performing soccer players in the age range of 18 to 24 years were recruited. At first, the players were subjected to baseline evaluation of psychomotor (i.e., reaction time - RT), physiological (viz. resting heart-rate; VO2Max, electrical muscle potentiality, etc.), and psychobiological indices (such as skin conductance components - latency, amplitude and recovery time). Thereafter, they were equally categorized into: Control Group, Experimental Group I [who received skin conductance (Sc) biofeedback training], and Experimental Group II [who received electromyography (EMG) biofeedback intervention training]. Participants of the experimental groups were subjected to their respective interventions (Sc & EMG biofeedback intervention training), which were imparted for 24 sessions (15 mins/day; 2 days/week for 12 weeks). After six weeks of intervention, mid-term evaluation of all of the aforementioned parameters (assessed during baseline evaluation) was performed. Thereafter, intervention sessions continued following the identical protocol for six weeks. At the end of the 12th week, a post-intervention assessment on all of the psychological, psychomotor and psychobiological variables was carried out on all of the participants to verify the effect of training on dependent measures. Post-intervention analyses revealed improvements in physiological, psychobiological and performance parameters, which could be rationally attributed to the differential biofeedback therapeutic interventions introduced to the experimental groups. The outcome suggested that both interventions facilitated improvement in bilateral shooting ability, while indepth analyses clarified that a higher extent of autonomic recovery emerged as the most significant factor facilitating shooting ability in the experimental groups.
Salmonella has caused foodborne illnesses globally and it has been a rising threat on fresh produce. The objective of this study was to determine the prevalence and concentration of Salmonella spp., Salmonella Typhi and Salmonella Typhimurium in freshly prepared fruit juice sold at hawker stalls. Analysis was conducted by employing most probable number-polymerase chain reaction (MPN-PCR). A total of 50 freshly prepared fruit juices were examined and the prevalence of Salmonella spp., Salmonella Typhi and Salmonella Typhimurium in the fruit juices were 34%, 20% and 10%, respectively, with an estimated microbial load varying from 0 to 42 MPN/g. Of the five different fruits, carrot juice had the highest prevalence of Salmonella spp. (60%) and Salmonella Typhi (40%). However, Salmonella Typhimurium was detected in apple (30%), orange (10%) and starfruit juice (10%). Factors contributing to the presence of Salmonella were cross-contamination and poor sanitation practice. Besides, negligence on temperature and storage time also led to the growth of Salmonella. Proper monitoring and risk assessment are needed in order to establish control measures to ensure the quality and safety of fruit juices in Malaysia.
This study aimed to determine the biofilm formation ability by Salmonella Typhi on cucumber, mango and guava surface, as well as to determine the relationship between time contact and biofilm formation. Crystal violet assay was performed to quantify the biofilm formation based on the value of optical density at 570 nm of the destaining crystal violet at the specific interval time. The result showed that the attachment of the bacterial cells on the fresh produce surface increased with the contact time. The readings of OD570at time 12 h for cucumber, mango and guava surfaces were 0.824, 0.683 and 0.598, respectively, indicating that the biofilm formation by Salmonella Typhi on different fresh produce surface varied with time. Since the result showed that Salmonella Typhi formed biofilm on fresh produce surfaces, hygienic practice from farm to fork including handling, processing, distribution and storage of the fresh produce should be of concern.
Hepatitis A virus infection occurs globally and is causing a public health concern, primarily in developing countries due to its persistent circulation in the environment. The improved sanitary condition and increase in awareness of personal hygiene have led to the marked reduction of HAV prevalence in industrialized countries during childhood and to a shift of the infection towards adulthood. HAV is an environmentally stable, positive single stranded RNA virus that is primarily transmitted by the fecal-oral route, person to person contact or ingestion of contaminated food and drink. One of the main causes leading to HAV infection is epidemiologically linked to the consumption of raw or undercooked shellfish particularly oysters and clams. Due to their filter-feeding style, these shellfishes readily concentrate viruses from the surrounding water containing municipal sewage, and as a consequence pose a health threat to consumers. Therefore, development of detection techniques possessing the requisite sensitivity and specificity for the practical routine monitoring purposes is of great importance necessary for the protection of shellfish-consuming public. Nucleic acid based method such as reverse transcription PCR has emerged as the popular method of choice in view of its rapidity, accuracy and
sensitivity in contrary of the time-consuming conventional cell culture and hybridization techniques. However, detection of hepatitis A virus is firstly hampered by the non-cytophatic effect of wild type HAV strain, secondly, the low concentration of viral genome present in the environmental sample which requires effective isolation and concentration of virions and lastly the labor-extensive purification and thorough removal of the abundance of the PCR inhibitors which will unfavorably reduce the efficiency of PCR detection.
The invention of microarray technology has enabled expression levels of thousands of genes to be monitored at once. This modernized approach has created large amount of data to be examined. Recently, gene regulatory network has been an interesting topic and generated impressive research goals in computational biology. Better understanding of the genetic regulatory processes would bring significant implications in the biomedical fields and many other pharmaceutical industries. As a result, various mathematical and computational methods have been used to model gene regulatory network from microarray data. Amongst those methods, the Bayesian network model attracts the most attention and has become the prominent technique since it can capture nonlinear and stochastic relationships between variables. However, structure learning of this model is NP-hard and computationally complex as the number of potential edges increase drastically with the number of genes. In addition, most of the studies only focused on the predicted results while neglecting the fact that microarray data is a fragmented information on the whole biological process. Hence this study proposed a network-based inference model that combined biological knowledge in order to verify the constructed gene regulatory relationships. The gene regulatory network is constructed using Bayesian network based on low-order conditional independence approach. This technique aims to identify from the data the dependencies to construct the network structure, while addressing the structure learning problem. In addition, three main toolkits such as Ensembl, TFSearch and TRANSFAC have been used to determine the false positive edges and verify reliability of regulatory relationships. The experimental results show that by integrating biological knowledge it could enhance the precision results and reduce the number of false positive edges in the trained gene regulatory network.
Objective: This case report highlights on the challenges in the management of people with bipolar disorder. Method: We report a case of 36 year-old lady living with this disorder and her journey in a search for a meaningful life. Result: Adherence to treatment is a major determinant of outcome in bipolar patient like Ms WMY. Poor insight, negative attitudes towards treatment and poor understanding of medications and the illness can all lead to reduced adherence. Conclusion: This case demonstrates on how poverty of insight, poor social support, on-going stressors with significant life events and poor compliance to treatment create a series of stumbling blocks in recovery from bipolar disorder.
Lattice Boltzmann Model for Shallow Water Equation with Turbulence Modeling (LABSWETM) is used to study the flow patterns of sidewall friction effects. The lattice Boltzmann method (LBM) approach in recovery the macroscopic governing equation which is shallow water equation from the microscopic flow behavior of particle movement as described by kinetic theory is explored. With the solution of force term to be used in lattice Boltzmann equation, the boundary condition of LBM is explored. With the use of bed and wall friction coefficients, the importance of Manning’s coefficient in determining the outcome of flow patterns simulation is explained. For model verification, the model represents a straight channel with a circular cavity attached to it. The result of this simulation includes the water circulation patterns, cross-section of average velocity distribution, and water depth. For validation, the cross-sections of the model in term of velocity vectors are compared against alternative numerical and experimental data.
Aquaculture is a growing industry with a great potential towards the contribution of the country’s total
fish requirement. Serious efforts have been done to develop and improve the production of fish by rearing high value fish in tanks or ponds. Under the Third National Agricultural Policy (1998-2010), the target is to annually produce 1.93 million tonnes of fish worth approximately RM8.3 billion by the year 2010. Consequently, the development of an automatic fish feeding machine can be very beneficial to the growth of the aquaculture industry. This device was developed to overcome labour problems in the industry and introduce a semi-automatic process in the aquaculture industry. It has the ability to dispense dried fish food in various forms such as pellets, sticks, tablets or granules into fish tanks or ponds in a controlled manner for a stipulated time. The automatic fish feeder is controlled by a digital timer and it is capable of feeding the fish in accordance with a pre-determined time schedule without the presence of an operator, and at a feeding rate of 250g/min. The feeder can be adjusted to the desired height and conveniently moved around to be positioned adjacent to the pond or tank. Meanwhile, its hopper can be covered and easily dissembled to change the size of the hopper to accommodate different capacities of feed. This automatic fish feeder can be implemented in aquaculture system to convenience to fish culturists.
Clubfoot is associated with leg length inequality, with the affected leg being shorter as a consequence of the hypoplasia. Early treatment of a minimally hypoplastic clubfoot usually allows catchup growth and both legs equalise in length after a few years. Late treatment however is associated with a shortening of the affected foot. A case is described where late treatment of a severe clubfoot is assocated with lengthening of the affected leg.
Mercury emission into the atmosphere is a global concern due to its detrimental effects on human health in general. The two main sources of mercury emission are natural sources and anthropogenic sources. Mercury emission from natural sources include volcanic activity, weathering of rocks, water movement and biological processes which are obviously inevitable. The anthropogenic sources of mercury emission are from coal combustion, cement production and waste incineration. Thus, in order to reduce mercury emission it is appropriate to investigate how mercury is released from the anthropogenic sources and consequently the mercury removal technology that can be implemented in order to reduce mercury emission into the atmosphere. Many alternatives have been developed to reduce mercury emission and the recent application of activated carbon showed high potential in the adsorption of elemental mercury. This paper discusses the ability of activated carbon and variable parameters that influence mercury removal efficiency in flue gas.