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The role of lysophosphatidic acid in the pathogenesis of oral squamous cell carcinoma / Mariati Abdul Rahman
Get PDFOral squamous cell carcinoma continues (OSCC) is the sixth most common cancer
worldwide and accounts for 300,000 new cases yearly with a five-year survival rate of
approximately 50%. Current treatment relies on surgery combined with radiotherapy
and/or chemotherapy. Major challenges include late presentation, treatment resistance,
second primary tumours and other co-morbidities. Thus, there is a compelling need to
develop novel therapeutic strategies to improve prognosis and reduce the late burden of
the disease and a further understanding into the molecular pathogenesis of the disease
could ultimately lead to better management strategies. This study investigated the role of
lysophosphatidic acid (LPA) signalling in the pathogenesis of OSCC. LPA is a lipid
signalling molecule that regulates many normal physiological processes. LPA is
increasingly recognized as being a central mediator of chronic inflammation, which
promotes cancer growth, immune invasion, metastasis and treatment resistance. The
results of the present study demonstrated that gene expression for the enzyme autotaxin,
which produces LPA, and LPA receptor 3 (LPAR3) were upregulated in OSCC tissues.
Functionally, LPAR3 was shown to mediate LPA-induced migration and invasion in
OSCC cell lines using the LPAR1/3 inhibitor, Ki16425, and shRNA mediated
knockdown of LPAR3. LPA protected OSCC cells exposed to low doses of radiation via
LPAR3, although effect appeared to be cell specific. Possible crosstalk between LPA,
EGFR and COX-2 was also investigated. LPA-induced phosphorylation of EGFR was
variable, possibly due to high basal levels of phosphorylated EGFR in some OSCC cell
lines. By contrast, LPA increased COX-2 levels in all OSCC cell lines examined via
LPAR3. Furthermore, LPA-induced OSCC cell migration was attenuated by the COX-2
inhibitor, NS398, and this inhibitor decreased the survival of LPA treated OSCC.
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Collectively these data show that COX-2 mediates some of the biological effects of LPA
in OSCC cells. Circulating plasma LPA levels in OSCC patients were also investigated
for the first time using LC-MSMS. In the present study, the profile of LPA species was
different in plasma from OSCC patients compared to normal controls. LPA levels were
significantly different among normal, early and advanced groups for LPA 18:0, LPA 18:1
and LPA 20:4. Pairwise comparison between two selected LPA species using scatterplots
differentiated the three sample groups (Pair1- LPA 18:1versus LPA 18:2, Pair2 – LPA
18:2 versus LPA 20:4 and Pair3- LPA 18:1 versus LPA 20:4.). Principle component
analysis clearly differentiated normal plasma from plasma from both early and advanced
cancer stages. Further analysis of the LPA profiles, rather than measuring individual LPA
species, might reveal novel pathological or prognostic benefits. In conclusion, LPA
synthesis and signalling is deregulated in OSCC. Crosstalk between LPAR3 and COX-2
mediates some of the pro-tumorigenic effects of this lipid which could potentially be
exploited to improve the management of this disease. Disruption of this signalling
pathway could provide novel therapeutic opportunities for patients with OSCC.
Keywords: LPA, OSCC, migration, radioresistance, crosstal
The impact of ignored negligible losses in engineering design: Baerodynamic drag on ET425M high speed train as study case / Muhammad Hafizuddin Zainal Abidin
Get PDFET425M high speed train built by Siemens for Express Rail Link to operate between Kuala Lumpur Sentral station to Kuala Lumpur International Airport. ET425M air conditioning units that installed on the roof section not incorporated with any air deflector design to mitigate additional air resistance. The additional drag resistance adds to train motion resistance that leads to higher traction effort thus conclude to additional power consumption. With using Ansys Fluent solver, the drag force, drag coefficient and max pressure acts on the original air conditioning unit design of ET425M is determined and compared with introduction of air deflector with various angle. With introduction of air deflector with angle of 20 degree, the drag force showed reduction of 27% reduction of drag force, 29% reduction of drag coefficient and 46% reduction of max pressure when train simulated moving at train velocity of 160Km/h. With using approximation and assumption method by comparing the difference of tractive effort to determine the relationship between reductions of air resistance with power consumption, a reduction of 3% is achieved which translated to saving of RM 7,458,674 for operation of 30 years with current train operation frequency
Assessment of awareness in mobile phone waste recycling program among consumers in Kuala Lumpur / Nur Syazwina Kamardzaman
Get PDFTechnology become more advance nowadays and the advancement produce a large numbers of electronic devices. The lifespan of the device become shorter when the feature become more tech. Due to the advancement of the technology, a large number of electronic waste were produce. E-waste are also one of the pollution that can affected the environment beside air and water pollution. Each year, roughly about 400 million waste mobile phones were generated around the world and make it as one of the cause of e-waste pollution (Xu, Zhang, He, Li, & Huang, 2016). This research project is to make assessment regarding consumers’ awareness and willingness on recycling e-waste mobile phone and tablet. This project also to make some recommendation regarding policies or framework for consumer e-waste recycling for Malaysia. Results shows that most of the respondents (56.67%) have 1-2 units of unused mobile phone. Respondents keeping their unused mobile phone at home as spare mobile phones. Respondents claimed that they changing their old mobile phone because it not working anymore, but choose to keep at home as spare phone. This shows that respondents have personal attachment with their old mobile phone and it will take some time to separate from old mobile phone. Majority of respondents (67.33%) stated that they never heard about any information regarding e-waste recycling. Its shows that lack of information lead to low rate of e-waste recycling. Respondents are aware that e-waste cannot mix with ordinary garbage, but lack of awareness make respondents do not recycle their unused mobile phone. Respondent have basic knowledge about materials inside mobile phone but less knowledge about mobile phone recycling. Information is important in enhancing consumers’ participation in recycling and government should provide more information about e-waste to increase consumers understanding especially about laws, regulation and recycling system. As respondents lack about e-waste recycling knowledge, their willingness to recycle their unused mobile phone are uncertain. The results shows that respondents are somewhat willing to take part if e-waste recycling was organised. This is due to their inadequate of information about the advantage when recycling waste mobile phone. Respondents need some incentive or compensation as motivation for their recycling action. Majority of respondents want cash payment or voucher as an incentive for their recycling action. Only 3.33% of respondents’ are willing to pay for recycling fee. Unwilling respondents (42.67%) stated that it is government responsibility to provide the recycling. Some also stated that it will burden their income and they are willing to sell the unused mobile phone to the second-hand market for low price. Experiences from developed countries shows that stable and complete recycling system require cooperation of all shareholder such as government, manufacturers, retailers, telecommunication service and consumers. Results shows that respondents thinks it is a responsibility of all share holder, and it shows they are aware about the cooperation of all shareholder. Improvement in law and regulation, development of e-waste infrastructural and education are some improvement that need to improve e-waste management system in Malaysia
Feasibility of diesel-biodiesel-alcohol blend fuels for diesel engine / Ali Shahir Shawkat
Get PDFThe energy policies and the ever-growing energy demand of the world require an alternative to fossil fuels. Among the alternative fuels, diesel–ethanol blend or the diesohol blend or the diesel-biodiesel blends might be good options. But these binary blends possess some problems. Diesel-biodiesel blends possess higher density, higher viscosity, lower heating value, poor cold flow properties and higher CN etc., which hinders its use. When biodiesel is added to diesel-bioethanol blends or bioethanol is added to diesel-biodiesel blends then the physicochemical properties of the ternary blends become almost similar to fossil diesel fuel and also remains stable. Thus, the use of ternary blends will eradicate the problems of using binary blends, make the biodiesel and bioethanol more feasible for the CI engines and in the meantime will increase the portion of the oxygen content of the fuel. The objectives of this study is to first develop a density and kinematic viscosity models to calculate the density and viscosity of ternary blends using bioethanol and biodiesel with diesel fuel and compare performance and emission of diesel-biodiesel-bioethanol blends with diesel-biodiesel-propanol, diesel-biodiesel-butanol, diesel-biodiesel-pentanol and diesel-biodiesel-hexanol blends. Five different biodiesels (palm, coconut, soybean, mustard and calophyllum inophyllum biodiesel) have been used with anhydrous bioethanol (99.9% pure) and neat diesel. Initially, density and viscosity models of neat diesel, 5 different biodiesels and bioethanol have been developed with respect to temperature (15°C-100°C). Later, 30 different diesel-biodiesel-bioethanol blends were prepared (each biodiesel×6 blends=30 blends) to measure the density and viscosity at different temperatures. To calculate the density of the diesel-biodiesel-bioethanol blends at 15°C, one density model is proposed with respect to components portion and their individual density which has a very high accuracy rate. To calculate the kinematic viscosity of diesel-biodiesel-bioethanol blends at 40°C, three correlation equations are proposed. To compare the performance and emission between ternary blends, the biodiesel has been kept constant while replacing the alcohol in the blend. Palm biodiesel (PBD) has been selected as the test biodiesel fuel which is considered as the most prospective renewable energy sources of Malaysia in recent years. Initially neat diesel and B20 (80% diesel+20% palm biodiesel) have been tested in the single cylinder Yanmar CI engine. Later, ternary blends of diesel-biodiesel-alcohol were tested. In all the ternary blends, the amount of diesel and PBD were kept constant which were 70% and 20% respectively while only varying the alcohol. Engine tests were conducted at variable speed, ranging from 1000 rpm to 2400 rpm and constant load at full throttle. Engine performance parameters like brake specific fuel consumption (BSFC), brake thermal efficiency (BTE) and engine emissions like nitrogen oxides (NOX), hydrocarbons (HC) and carbon monoxide (CO) were measured. Performance and exhaust emissions variation of the ternary blends from the baseline fuels, i.e. neat diesel and P20, were compared for the assessment of the improvement quantitatively
Sleepiness and tiredness among doctors working in a tertiary hospital: Is it work related or is there underlying sleep disorders? / Imelda Kong Wei
Get PDFBackground
Doctors who work in a tertiary hospital may frequently complain of sleepiness
and tiredness. Majority of trainee doctors attribute these symptoms to the nature of their
work having to do frequent night shifts or more than 24 hours work shift causing
irregular sleep patterns and sleep deprivation. There are still limited data regarding sleep
disorders among trainee doctors. Hence this study is to look at prevalence of obstructive
sleep apnea (OSA) among doctors working in a tertiary hospital and also to identify if
the sleepiness and tiredness is caused by undiagnosed OSA.
Methods
A prospective cross-sectional study is performed among doctors working in a
tertiary hospital. All doctors recruited will be required to fill up the demographic data,
STOP-Bang and Epworth Sleepiness Scale questionnaires. A wristwatch pulse oximetry
will be given to each participant for home nocturnal oxygen saturation monitoring during
sleep. Participant will have to wear the wristwatch to sleep overnight till the next day.
Participant with oxygen desaturation index (ODI) of 10 and above will be offered a home
sleep apnea testing (ApneaLink ResMed) to further evaluate the apnea hypoapnea index
(AHI) for diagnosis of moderate to severe OSA. The STOP-Bang and ESS scores will
be compared and correlate with data collected from the wristwatch pulse oximetry.
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Results
Among the 130 of doctors recruited in this study, 39 (30%) found to have ODI
of >5 and 19 subjects with ODI >10. Further evaluation with home sleep study showed 4
(3.1%) doctors had moderate OSA and 6 (4.6%) confirmed to have severe OSA. The
prevalence of excessive daytime sleepiness (ESS >10) was 21% , tiredness (51%) and
perception of inadequate sleep (41%). However there is no association between tiredness
or sleepiness and OSA. The predictors of perception of having inadequate sleep were
snoring (OR= 0.32; p=0.0015; 95%CI:0.12-0.8) and average sleep time during on-call
(OR=0.57; p<0.001; 95%CI:0.4-0.8). While BMI and snoring were the significant
predictors for OSA with odd ratio (OR) of 1.33 (p<0.001; 95% CI:1.14-1.55) and 5.14
(p=0.006; 95% CI:1.59-16.67) respectively.
Conclusions
Our study have shown significant prevalence of undiagnosed moderate to severe
OSA among young doctors. Snoring and BMI are the only independent predictors for
OSA. STOP BANG is not so accurate to predict OSA in young, healthy and non-obese
population. ODI from high resolution oximetry is a good screening tool to detect OSA.
We have demonstrated that shorter average sleep during on-call time as well as snoring
are predictors of perception of always having inadequate sleep among the doctors
participated in this study
Anaesthesia for laparoscopic abdominal surgery: A survey on the choice of airway management amongst anaesthesiologists / Imaan Abdul Rahim
Get PDFBackground
Laparoscopic abdominal surgery is now a widely established minimally invasive
surgical technique. Anaesthetic techniques have evolved and been refined to tailor to the
anticipated physiological changes associated with laparoscopic abdominal surgery. The
cuffed tracheal tube was previously thought to be the gold-standard airway management
in laparoscopic abdominal surgeries. This is slowly being replaced by second generation
supraglottic airway devices. This survey aims to examine and compare practices in airway
management in laparoscopic abdominal surgery.
Methods
This study is a cross-sectional survey involving various government and private
hospitals in the Klang Valley and Selangor. The survey questionnaire was distributed via
email in Google Form format. The responses were tabulated and analysed, with the chisquare test performed to calculate p-value for sector and experience.
Results
The questionnaire was distributed to a total of 129 anaesthesiologists. Out of
those, we received 95 responses but were only able to use 90 after considering inclusion
and exclusion criteria. The majority of respondents (67.8%) use only ETT whereas 32.2%
use LMA. Cross tabulation revealed significant correlation between work sector and
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duration of experience in choice of airway management with p value for each being 0.009
and 0.027 respectively. Most in the LMA group choose low risk patients and maintain
certain parameters to minimise risk of aspiration. The ETT-only group mainly cited lack
of experience of junior colleagues and support staff, and potential medicolegal
repercussions (49.1%, 39.2% and 39.2% respectively) as reasons for their choice.
Conclusion
Junior trainees and anaesthetic support staff should be educated on how to ensure
safe usage of LMA in laparoscopic abdominal surgery. At the same time, more evidence
needs to be gathered to enable the provision of such a training. A localised protocol could
also be created to ensure standard practices can be implemented in the use of LMA in
LAS
Image classification and segmentation for efficient surveillance applications / Maryam Asadzadeh Kaljahi
Get PDFImage or video-based surveillance systems are playing a vital role in developing smart city and disaster management, such as flood and air pollution, etc. The need for the above surveillance systems is increasing exponentially. As a result, there is a demand for developing an accurate, efficient and safe system. There are existing systems for solving the above issues but the performance of the systems degrades or inconsistent for the different applications and situations. Besides, most existing systems do not aim to combine image processing and networking as one system for addressing the challenges. Therefore, there is immense scope for developing a new image-based surveillance system, which can cope with the causes of different applications and situations with minimum changes. To address the above research challenge, the proposed work is divided into three sub-challenges, namely, classification of images for developing a generalized system, segmentation for image size reduction and detecting region for safe landing for the purpose of safety. To solve the above challenge-1, in the past, the methods are developed, which include content-based image retrieval, scene categorization, and deep learning-based. The main issue of these methods is that the methods are limited to particular shapes of the objects in the images. In the same way, deep learning-based methods expect a large number of labeled samples and high computations. Therefore, the methods are limited to specific classification but not the classification considered in this work, which requires the generalized method. Thus, the proposed work aims at developing a new method for extracting edge strength and sharpness for classification of different image classes namely, soil, flood, air pollution, plant growth and garbage scene images. The reason to choose the above features is that these features can be used to extract unique observation in the images irrespective of objects shape. To address the challenge-2, edge, texture, color and deep learning-based methods are proposed in the past. However, the methods are sensitive to background complexity and may not work
well for the proposed image classes because each image can contain multiple colors, texture, etc. Therefore, the proposed work introduces a general saliency-based method for segmenting common region of the images. To find a solution to the above challenge-3, the existing methods extract texture, edges, and color for detecting flat region (safe landing zone) in the images. However, these methods are not adequate for the proposed images of complex background. Hence, the proposed work explores Gabor orientation responses for studying flat and rough region instead of magnitude values. The developed methods would be evaluated on different datasets to validate their performance
The role of religion on sport anxiety among elite athletes in Malaysia: An exploratory study / Syazana Shahdan
Get PDFAnxiety is known to have an influence on psychological and physiological aspects of athletes especially when it becomes uncontrollable, and religion has been viewed with great potential in controlling anxiety levels. Hence, this study aimed to explore the role of religion on sport anxiety among elite athletes in Malaysia. It employed the Interpretative Phenomenological Analysis (IPA) approach in order to have a deeper understanding of the research topic. Seventeen elite athletes (10 males, 7 females, age range: 19-to-26 years old) with various sport background voluntarily participated in arranged interviews. There are four religious affiliations involved in this study: Islam, Buddhism, Christianity, and Hinduism. The study found six religious coping strategies and seven positive psychological effects of utilizing religion to cope with sport anxiety. Prayers was identified as the most popular strategy used and calmness was the most mentioned effect of religion when utilize to alleviate anxiety levels. The findings show that religion can play an important role as an effective coping strategy to deal with sport-related anxiety among athletes who believe in religion
The interaction effect of organizational and individual factors on knowledge sharing behavior: The case of Kazakhstan / Sanat Kozhakhmet
Get PDFOne of the key challenges for contemporary organizations is finding methods of motivating employees to share their knowledge and expertise with their peers. A number of firms try to deal with this challenge by implementing different knowledge management systems. However, despite investments in knowledge management systems, knowledge sharing often does not simply occur. Research findings report that a significant reason for this is that individuals are often reluctant or uneager to share their personal knowledge. Consequently, it is important to understand the factors that might influence employees’ behavior in this arena. Previous studies have attempted to understand knowledge sharing behavior from different perspectives; however, only a few of them have pursued both an organizational and a psychological perspective on how knowledge sharing behavior is instigated. The aim of this study is to fill that gap by investigating how investment in employee development and psychological capital influence knowledge sharing behavior. In addition, this research seeks to explore how organizational identification moderates the investment in employee development-psychological capital and psychological capital-knowledge sharing behavior links. From a critical review of the literature, a research model was proposed to address the answers to the research questions. Data was collected through questionnaires completed by 240 employees of large companies operating in Kazakhstan, and Partial Least Squares Path Modeling was used to analyze the data. The research findings support four out of the six hypotheses. The results revealed that the influence of investment in employee development on knowledge sharing behavior was mediated by psychological capital. Moreover, it was found that organizational identification moderates the relationship between employees’ psychological capital and knowledge sharing behavior. However, the same variable did not modify the relationship between investment in employee development and psychological capital. The results of this research can help companies by allowing them to better understand how to foster knowledge sharing behavior in a more effective way. In addition, the study provides theoretical and practical contributions to knowledge management studies
A critical discourse analysis of the representations of sex trafficking victims in Malaysia / Puspalata C Suppiah
Get PDFTrafficking of women for sexual purposes has been a major cause of concern in recent years. It is a global phenomenon that has spread extensively in both developing and developed countries. In Malaysia, sex-trafficking victims have been subjected to severe marginalisation in society unlike other social groups such as migrants and refugees. Within the legislation, victims are criminalised and treated as illegal immigrants, and therefore charged with immigration offences. More critically, the conflation between the terms “victims of sex trafficking” and “prostitutes” has led to the use of the terms interchangeably by popular mainstream newspapers in Malaysia. The disparity that exists between both groups can negatively impact on victims’ lives, giving rise to a growing body of literature that criticises the discourse of trafficking. The way sex-trafficking victims are represented differently could further lead to the denial of sex trafficking as a legitimate concern in Malaysia. In order for sex trafficking to be viewed as an important and urgent human rights issue, it is necessary to highlight the ways in which victims are represented and explain why certain representations can be damaging for such a social group. In this study, the representation of sex-trafficking victims is explored from two perspectives: the media and interview narratives. The Discourse-historical Approach (DHA) and Sociosemantic Network of Social Actors were primarily used as frameworks to examine the media representation of sex-trafficking victims. A total of 120 newspaper articles between 2010 and 2016 were selected for analysis. Victims’ personal experiences and self-representations were also examined through a Thematic Narrative Approach based on interview data of 15 women from five Southeast Asian countries. The interviews were conducted both at a national shelter home for rescued sex workers and in the field. Analysis of media texts revealed foreign women in sex work being commonly depicted as offenders in terms of legislation, rather than as victims of sex trafficking. Victims’ voices remain underrepresented while an extensive amount of space was given to prominent and elite social actors. Analysis of the interview narratives led to the emergence of four main themes that drew attention to victims’ vulnerability and lack of power. In particular, the stigma of “whore” attached to sex work had affected the women despite their legitimate victim status. Analysing the voices of women in sex work offers new perspectives about sex-trafficking issues that are affecting millions of women in society and ensures that research is responsive to their needs since it is through these women’s voices that “unheard” stories are exposed. Additionally, the knowledge generated from this study could provide insights for newspaper journalists so that they become more sensitive and responsible of the media coverage on sex trafficking as well as promote legislative reform about sex trafficking