45 research outputs found
Robotic System For Hazardous Chemical Experiment
Normally the experiments conducted in laboratories are done manually. This may
lead to unpredictable accidents. It can cause damage to both experiment apparatus
and its user. Results obtained from the experiment conducted manually are not
accurate especially if the same experiment has to be repeated for many times. This
technique needs to be improved.
The main objective of this project is to provide a robotic system that is capable of
handling hazardous chemical processing and experiments at laboratories. It can be
reprogrammed to perform various tasks with flexible degrees of freedom. This system is called Robolab. This project starts from the development of a simple
concept of XYZ movements and gripper, into a final form of a Cartesian robot.
The main structure of the Robolab can be divided into software and hardware
parts. The software is responsible to drive the robotic arms in order to move to a
precise position and at the same time control the inputs and outputs devices of the
system. The program consists of various functions such as home routine, stop
routine, process routine, jog/manual routine and on-error routine. Meanwhile, the
hardware of the Robolab system can be divided into electrical and mechanical
modules.
The electrical module consists of a power distribution system, a SmartStep/3
control board and a personal computer. The mechanical consists of an end
effector, a pneumatic system, a Z-axis module, a Y-axis module, an X-axis
module, a pipette module, a vibrator module, a conveyor belt system, a system
base and jigs and fixtures module.
A personal computer is needed to download program into the EPROM of the
motion controller through the connection of RS232 host link system. The motion
controller acts as the main processor of the robotic system. The actuators are used
to drive the mechanical robotic arm. This robot also has a built-in fault detection
system. It will inform its main controller if any particular faults occur to the
system.The SmartStep/3 controller is chosen for this project to control the robot. CTERM,
a terminal emulator is specially configured for the controller to use on pc. MlNT's
flexible and powerful command set is used as a solution to motion control
applications.
From the experimental results, it is proven that the proposed robotic arm was
successfully designed, constructed and controlled
Spatial and temporal dynamics of suspended sediment concentrations in coastal waters of the South China Sea, off Sarawak, Borneo: ocean colour remote sensing observations and analysis
High-quality ocean colour observations are increasingly accessible to support various monitoring and research activities for water quality measurements. In this paper, we present a newly developed regional total suspended solids (TSSs) empirical model using MODIS Aqua's Rrs(530) and Rrs(666) reflectance bands to investigate the spatial and temporal variation in TSS dynamics along the southwest coast of Sarawak, Borneo, with the application of the Open Data Cube (ODC) platform. The performance of this TSS retrieval model was evaluated using error metrics (bias = 1.0, MAE = 1.47, and RMSE = 0.22, in milligrams per litre) with a log10 transformation prior to calculation as well as using a k-fold cross-validation technique. The temporally averaged map of the TSS distribution, using daily MODIS Aqua satellite datasets from 2003 until 2019, revealed that large TSS plumes were detected – particularly in the Lupar and Rajang coastal areas – on a yearly basis. The average TSS concentration in these coastal waters was in the range of 15–20 mg L−1. Moreover, the spatial map of the TSS coefficient of variation (CV) indicated strong TSS variability (approximately 90 %) in the Samunsam–Sematan coastal areas, which could potentially impact nearby coral reef habitats in this region. Study of the temporal TSS variation provides further evidence that monsoonal patterns drive the TSS release in these tropical water systems, with distinct and widespread TSS plume variations observed between the northeast and southwest monsoon periods. A map of relative TSS distribution anomalies revealed strong spatial TSS variations in the Samunsam–Sematan coastal areas, while 2010 recorded a major increase (approximately 100 %) and widespread TSS distribution with respect to the long-term mean. Furthermore, study of the contribution of river discharge to the TSS distribution showed a weak correlation across time at both the Lupar and Rajang river mouth points. The variability in the TSS distribution across coastal river points was studied by investigating the variation in the TSS pixels at three transect points, stretching from the river mouth into territorial and open-water zones, for eight main rivers. The results showed a progressively decreasing pattern of nearly 50 % in relation to the distance from shore, with exceptions in the northeast regions of the study area. Essentially, our findings demonstrate that the TSS levels on the southwest coast of Sarawak are within local water quality standards, promoting various marine and socio-economic activities. This study presents the first observation of TSS distributions in Sarawak coastal systems with the application of remote sensing technologies and aims at enhancing coastal sediment management strategies for the sustainable use of coastal waters and their resources.</p
Hypersensitivity reactions to human papillomavirus vaccine in Australian schoolgirls: retrospective cohort study
Objective To describe the outcomes of clinical evaluation, skin testing, and vaccine challenge in adolescent schoolgirls with suspected hypersensitivity to the quadrivalent human papillomavirus vaccine introduced in Australian schools in 2007
Permissive Transcriptional Activity at the Centromere through Pockets of DNA Hypomethylation
DNA methylation is a hallmark of transcriptional silencing, yet transcription has been reported at the centromere. To address this apparent paradox, we employed a fully sequence-defined ectopic human centromere (or neocentromere) to investigate the relationship between DNA methylation and transcription. We used sodium bisulfite PCR and sequencing to determine the methylation status of 2,041 CpG dinucleotides distributed across a 6.76-Mbp chromosomal region containing a neocentromere. These CpG dinucleotides were associated with conventional and nonconventional CpG islands. We found an overall hypermethylation of the neocentric DNA at nonconventional CpG islands that we designated as CpG islets and CpG orphans. The observed hypermethylation was consistent with the presence of a presumed transcriptionally silent chromatin state at the neocentromere. Within this neocentric chromatin, specific sites of active transcription and the centromeric chromatin boundary are defined by DNA hypomethylation. Our data demonstrate, for the first time to our knowledge, a correlation between DNA methylation and centromere formation in mammals, and that transcription and “chromatin-boundary activity” are permissible at the centromere through the selective hypomethylation of pockets of sequences without compromising the overall silent chromatin state and function of the centromere
Screening of endophytic fungi for biofuel feedstock production using palm oil mill effluent as a carbon source
Edwin Sia Sien Aun1, Joanne Yeo Suan Hui1, Julie Wong Wei Ming1, Jenny Choo Cheng Yi1, Changi Wong1,
Aazani Mujahid2, Moritz Müller1
Denial of long-term issues with agriculture on tropical peatlands will have devastating consequences
Non peer reviewe
Ndfip1 regulates nuclear Pten import in vivo to promote neuronal survival following cerebral ischemia
PTEN (phosphatase and tensin homologue deleted on chromosome TEN) is the major negative regulator of phosphatidylinositol 3-kinase signaling and has cell-specific functions including tumor suppression. Nuclear localization of PTEN is vital for tumor suppression; however, outside of cancer, the molecular and physiological events driving PTEN nuclear entry are unknown. In this paper, we demonstrate that cytoplasmic Pten was translocated into the nuclei of neurons after cerebral ischemia in mice. Critically, this transport event was dependent on a surge in the Nedd4 family–interacting protein 1 (Ndfip1), as neurons in Ndfip1-deficient mice failed to import Pten. Ndfip1 binds to Pten, resulting in enhanced ubiquitination by Nedd4 E3 ubiquitin ligases. In vitro, Ndfip1 overexpression increased the rate of Pten nuclear import detected by photobleaching experiments, whereas Ndfip1⁻/⁻ fibroblasts showed negligible transport rates. In vivo, Ndfip1 mutant mice suffered larger infarct sizes associated with suppressed phosphorylated Akt activation. Our findings provide the first physiological example of when and why transient shuttling of nuclear Pten occurs and how this process is critical for neuron survival.Jason Howitt, Jenny Lackovic, Ley-Hian Low, Adam Naguib, Alison Macintyre, Choo-Peng Goh, Jennifer K. Callaway, Vicki Hammond, Tim Thomas, Matthew Dixon, Ulrich Putz, John Silke, Perry Bartlett, Baoli Yang, Sharad Kumar, Lloyd C. Trotman, and Seong-Seng Ta
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Investigative study about sources and consequences of emotional toxicity in the workplace.
This paper uses the term 'emotional toxicity' to denote stress in the workplace to suggest that the consequences of stress are toxins which can and do cause harm. This paper deals with two constructs of emotional toxicity; its sources and consequences. Qualitative research design and methods are deployed in three areas : the data source is obtained from a compilation of verbatim interviews given by people talking about their work, a grounded theory approach was used to do the data analyse, and finally, the presentation of the findings was done using illustrative data and narrative means.Master of Science (Knowledge Management
Bioassay-guided isolation of antibiotics from selected marine bacteria
As a response to the widespread emergence of antibiotic resistant bacteria, a study was devised to isolate selected marine bacteria to test for its antibacterial activity. A total of six bacterial isolates which were P5.1.2, 3.1.2, B2.4A, B.24C, B2.6A, and S 1.2.3 were subjected to preliminary screening via agar-well diffusion assay against Gram-positive (Staphylococcus aureus) and Gram negative (Escherichia coli, Enterobacter aerogenes, and Salmonella typhi) test bacteria. Bacterial isolate P5.1.2 which was tentatively identified as Klebsiella sp. was only found active against Gram positive test bacteria while others showed no activity. Antibiotic extraction from this isolate P5.1.2 was done from culture growing it on solid media. Dried cultures were then subjected to subsequent extraction using six solvents which were hexane, chloroform, dichloromethane, ethyl acetate, methanol, and water. A time-course experiment was conducted to determine the optimum age of harvesting. All six extracts from the selected bacterial isolate were subjected to antibacterial screening against the test bacteria via agar-well diffusion method and the presence of halo around the wells was examined. Methanol, chloroform, and ethyl acetate crude extracts showed antibacterial activities and the minimum inhibitory concentration (M1C) values were I mg/ml, 0.25 mglml and 0.125 mg/ml respectively. These results supports that marine environment is capable of producing new antibiotic substances