Mechanistic behaviour and molecular interactions of heat shock protein 47 (HSP47)

This project involves the study of heat shock protein 47 (HSP47), which is a molecular chaperone crucial for collagen biosynthesis. It exhibits a high degree of sequence homology with members of the serine protease inhibitor (serpin) superfamily, though HSP47 does not possess the inhibitory activity. It is a single-substrate chaperone, and binds only to collagen. ‘Knock-out’ of the hsp47 gene impairs the secretion of correctly folded collagen triple helix molecules leading to embryonic lethality in mice. Thus the aim of this project was to elucidate the specific mechanism that governs the binding to and release from collagen at the molecular level, known as the ‘pH-switch mechanism’. Emphasis is given on histidine (His) residues as the HSP47-collagen dissociation pH is similar to the pKa of the imidazole side chain of His residues. Site directed mutagenesis was used to mutate surface His residues, based on a mouse HSP47 homology model. The effects of the mutations on the behaviour of HSP47 were then assessed by collagen binding assays and structural analyses with circular dichroism (CD). All mutants were found to have good solubility and retain their binding ability to collagen like wild-type HSP47 in batch assay, but perturbed behaviour was seen in column experiment. Mutation of His residue at position 191 (H191) causes the shift in the collagen dissociation pH, while mutation of H197 and/or 198 disrupt the specific HSP47-collagen interaction. H191, 197 and 198 are predicted to be located in the region near the C-terminus of strand 3 of β-sheet A (s3A) in the homology model, a region specifically known as the ‘breach cluster’ in serpin nomenclature. The extent of conformational rearrangement of this region was further investigated by means of intrinsic tryptophan fluorescence spectroscopy using a series of single tryptophan (Trp) mutants. Results from analyses performed on the mutants did not contradict the observation seen in His mutational work, as Trp residues in the ‘breach’ cluster are likely to be located in the dynamic region of HSP47 pH-triggered conformational change. In conclusion, this study establishes the importance of His residues in the ‘breach cluster’ to HSP47 pH-switch behaviour. Finally, a model for HSP47 pH-switch mechanism was proposed from data obtained via mutagenesis experiments. The model is hoped to assist future research into HSP47 cellular behaviour and will also be of great use in therapeutic applications involving the molecular chaperone

Investigation of linearity between mechanical properties of wood using graphical method

Some basic requirements are set for small clear specimen data to incorporate Malaysian timbers into equivalent European timber strength classes. In general, the correlation between structural and small clear specimen test results must be established for every timber group regardless of origin. This paper introduces a sort-plot technique for analysing the correlation of some mechanical properties of timber in selecting appropriate parametric model. Bending test was conducted on mixed species hardwoods for the determination of strength and stiffness values of both structural and small size specimens. The results showed that the sort-plot diagrams demonstrate an obvious linearity pattern between timber properties despite having poor regression values. The technique verified that properties of timber in structural and small size specimens correlated linearly

Managing small computer training premises: A case study on Pusat Komuniti Siber, Jitra

There has been a vast number of training premises set-up and introduced lately for providing community with opportunity to continue learning. This is an advantage not only for their existence but also the fees are affordable even though by local communities. Well-managed training programs by considering the trainees, trainers, apparatus and teaching medium can contribute to the basis of producing K-Workers. A research has been conducted partly using TIER model to investigate whether the computer training program at Pusat Komuniti Siber (PKS), Jitra has been well managed using TIMO model and the results show that the mean after training program is far encouraging than the mean before training. This paper's objectives are to illustrate the training program - how the training is organized - and trainees' perception towards the training program. Other than that, this paper visualizes what is being done at PKS, Jitra

EEG affective modelling for dysphoria understanding

Dysphoria is a state of dissatisfaction, restlessness or fidgeting. It is a state of feeling unwell in relation to mental and emotional discomfort. If this state is not carefully handled, it may lead to depression, anxiety, and stress. To date, 21-item instruments of Depression, Anxiety and Stress Scale (DASS) is employed to measure dysphoria. Although DASS provides a quantitative assessment of the human affective state, it is subjected to interpretation. To complicate matters, pre-cursor emotion and pre-emotion of the participants can result in biasness of the DASS report. Hence, a more direct method in measuring human affective state by analyzing the brain pattern is proposed. The approach can also address the dynamic affective state which is needed in detecting dysphoria. Brain waves pattern are collected using the electroencephalogram (EEG) device and used as the input to analyze the underlying emotion. In this paper, relevant features were extracted using Mel-frequency cepstral coefficients (MFCC) and classified with Multi-Layer Perceptron (MLP). The experimental results show potential of differentiating between positive and negative emotion with comparable accuracy. Subsequently, it is envisaged that the proposed model can be extended as a tool that can be used to measure stress and anxiety in work places and education institutions

Performance of oscillatory flow reactor and stir tank reactor in solvent fermentation from palm oil mill effluent

Advance in mixing technology has developed a new way of mixing fluids by introducing an oscillatory motion to replace the conventional mechanical agitation or an air bubble displacement. This new way of mixing breakthrough has been implemented in an Oscillatory Flow Reactor (OFR). This research will be focus on the performance of OFR as a bioreactor by comparing with Stir Tank Reactor (STR), which is the traditional device in fermentation. The experimental work was conducted in an OFR and a STR with a working volume of 1.5 l. Solvent production strain, Clostridium acetobutylicum NCIMB 13357 was grown in OFR and STR, using fresh Palm Oil Mill Effluent (POME) as growth medium. All of the experiments were conducted anaerobically under batch mode for 72 hours at constant temperature of 35°C. Comparisons of the growth trend and solvent fermentation performance for both devices were investigated. Total solvents (acetone, butanol and ethanol) produced in an OFR was comparable with that of STR. Total solvents production in OFR is 1.8 times higher than that of STR resulted in total 1.6 g/l of solvents. The results of this investigation showed that OFR has an excellent potential as an alternative device in fermentation processes

Dysphoria detection using EEG signals

Dysphoria is a state faced when one experienced disappointment. If it is not handled properly, dysphoria may trigger acute stress, anxiety and depression. Typically, the individual who experienced dysphoria are in-denial because dysphoria is always being associated with negative connotations such as incompetency to handle pressure, weak personality and lack of will power. To date, there is no accurate instrument to measure dysphoria except using questionnaire by psychologists, such as: Depression, Anxiety and Stress Scale (DASS) and Nepean Dysphoria Scale (NDS-24). Participants may suppress or exaggerate their answers resulting in misdiagnosis. In this work, a theoretical Dysphoria Model of Affect (DMoA) is developed for dysphoria detection. Based on the hypothesis that dysphoria is related to negative emotion, the input from brain signal is captured using electroencephalogram (EEG) device to detect negative emotions. The results from analyzing the EEG signals were compared with DASS and NDS questionnaires for correlation analysis. It is observed that the proposed DMoA approach can identify negative emotions ranging from 55% to 77% accuracy. In addition, the NDS questionnaire seems to provide better distinction for dysphoria as compared to DASS and is similar to the result yielded by DMoA in detecting dysphoria. Thus, DMoA approach can be used as an alternative for early dysphoria detection to assist early intervention in identifying the patients’ mental states. Subsequently, DMoA approach can be implemented as another possible solution for early detection of dysphoria thus providing an enhancement to the present NDS instruments providing psychologists and psychiatrists with a quantitative tool for better analysis of the patients’ state

Interpretasi guru Bahasa Melayu terhadap penyerapan elemen falsafah bahasa untuk penyatupaduan nasional: satu kajian analisis keperluan

Kajian ini bertujuan untuk meninjau keperluan pembangunan model falsafah bahasa untuk penyatupaduan nasional berdasarkan pandangan guru Bahasa Melayu di sekolah kebangsaan dan sekolah jenis kebangsaan. Tatacara penyelidikan ini menggunakan kaedah kajian reka bentuk dan untuk tujuan pembangunan model. Berpandukan kaedah ini fasa analisis keperluan merupakan fasa pertama daripada tiga fasa yang dijalankan bagi memastikan model yang dibangunkan boleh menepati kehendak pengguna. Dalam fasa analisis keperluan ini, pengumpulan data dijalankan melalui kaedah tinjauan menggunakan soal selidik ke atas 200 orang peserta kajian yang meliputi guru Bahasa Melayu yang mengajar di Sekolah Menengah Kebangsaan (SMK), Sekolah Kebangsaan (SK), Sekolah Jenis Kebangsaan Cina (SJKC) dan Sekolah Jenis Kebangsaan Tamil (SJKT) di negeri Kelantan, Pulau Pinang, Negeri Sembilan dan Perak. Analisis data dibahagikan kepada empat tema utama, iaitu: (1) Persepsi guru tentang konsep Falsafah Bahasa dalam pendidikan Bahasa Melayu, (2) Persepsi guru terhadap konsep penyatupaduan Nasional dalam hubungannya dengan pendidikan Bahasa Melayu, (3) Tahap kemahiran guru berkaitan elemen-elemen falsafah bahasa untuk dilaksanakan dalam proses pengajaran bahasa Melayu, (4) Tahap penerimaan guru terhadap penyerapan elemen falsafah bahasa dalam pengajaran Bahasa Melayu sebagai strategi penyatupaduan nasional. Dapatan kajian menunjukkan bahawa model falsafah bahasa untuk penyatupaduan nasional berpotensi untuk dibangunkan. Hasil dapatan juga akan digunakan dalam fasa pembinaan model prototaip di fasa berikutnya. Penemuan ini dijangka dapat memberikan gambaran bahawa pembangunan model falsafah bahasa untuk penyatupaduan nasional ini diperlukan untuk memupuk penyatupaduan dalam kalangan murid pelbagai etnik berdasarkan pandangan guru Bahasa Melayu yang mengajar di kawasan bandar dan luar bandar