Optimization Strategies, Kinetics and Modeling of Cell Growth in Centella Asiatica Cell Culture

C. asiatica (Umbelliferae) or locally known as "pegaga" cell suspension culture is used as a model system to produce triterpenoids (TTPs). Cell growth and TTPs production were optimized at shake flask level. Different factors such as nutritional requirement and environmental conditions were screened and optimized using Response Surface Methodology (RSM) experimental design. Preliminary study of laboratory-scale bioreactor was done to study cell growth at regulated pH. Kinetics and modeling studies were carried out aimed at evaluating growth and production parameters for better understanding and control of the process. This study was conducted as foundation for production of triterpenoids at commercial scale. Growth medium (G) was developed for optimum cell growth by manipulation of different inoculum age and size, sucrose concentration, hormone combination and concentration, incubatOptimization strategies by RSM has established cell growth of C. asiatica above 16 g L⁻¹ at 25°C, pH 5.65 and light intensity of 734 lux; medium NH₄⁺:NO₃⁻ ratio between 0.45-0.9, higher pol-at 2.6 mM, sucrose concentration around 6.68% in combination with 0.84 mg L⁻¹ IAA and 1.17 mg L⁻¹ BAP and higher total number of nitrogen around 40 mM. Maximum cell dry weight around 27 g L⁻¹ was attained with G medium. However, TTPs production was not significantly affected by all factors because of very low production. Cell growth rate at 0.09 day⁻¹ (td=7.5 days) was 1.5 times higher when medium pH was controlled at pH 4 in stirred-tank: bioreactor. However, maximum cell dry weight at 8.6 g L⁻¹ was 1.5 times higher when pH was not controlled, with in almost three times more efficient sucrose utilization at 0.28 g cell g⁻¹ sucrose. Higher growth rate at 0.18 day⁻¹ in bioreactor cultivation (B) was only 20% higher than shake flask cultivation However, maximum cell dry weight at 10.5 g L⁻¹ in M was 14% higher than in B.A 97% confidence was achieved by fitting three unstructured growth models; Monod, Logistic and Gompertz equations to the cell growth data. The deviation in Logistic and Gompertz models could be due the model was developed for substrateindependent growth and fungi growth, respectively

Penggunaan strategi komunikasi dalam rutin perundingan makna

Sifat kerjasama dalam komunikasi antara pelajar dan penutur natif dilihat dapat membantu meningkatkan kecekapan komunikatif pelajar. Kecekapan komunikatif merupakan pendekatan yang memberi fokus kepada interaksi dan komunikasi. Kajian ini merupakan sebuah kajian kualitatif yang menganalisis data yang diperolehi daripada interaksi pelajar bersama penutur natif bahasa Sepanyol. Kajian ini dijalankan untuk melihat penggunaan strategi komunikasi (SK) dalam rutin perundingan makna oleh pelajar bahasa Sepanyol dalam komunikasi mediasi komputer secara sinkronis semasa perbualan bersama penutur natif berlangsung. Sebanyak 12 jenis SK yang dikaji dalam kajian ini. Seramai 60 orang pelajar elektif bahasa Sepanyol dari tiga buah universiti iaitu Universiti Kebangsaan Malaysia, Universiti Utara Malaysia dan Universiti Putra Malaysia dipilih sebagai responden kajian. Responden terdiri daripada pelajar Tahap I, Tahap II dan Tahap III. Data utama kajian ialah teks perbualan pelajar bersama penutur natif dalam laman sembang atas talian. Perbualan ini merupakan perbualan bebas yang berlangsung selama dua jam bagi setiap sesi. Jumlah keseluruhan masa perbualan adalah selama 120 jam. Tujuan penggunaan SK adalah untuk meningkatkan kefasihan dan kelangsungan perbualan tanpa terlalu menitikberatkan ketepatan dalam konteks bahasa sasaran. Model Zhao (2010) dan Model Smith (2003) dijadikan panduan untuk melihat kepada fasa rutin perundingan makna. Dapatan kajian menunjukkan bahawa pelajar tanpa mengira tahap kecekapan bahasa menggunakan SK tertentu dalam setiap fasa rutin perundingan makna. Penggunaan SK yang sesuai dalam rutin perundingan membantu pelajar untuk menjayakan komunikasi. Implikasi kajian ini menunjukkan para pelajar dapat meningkatkan kecekapan komunikatif mereka dalam bahasa asing yang dipelajari

Ultrasonication effects on ultrafiltration membrane cleaning and fouling mitigation

Mitigation of fouling on hollow fiber ultrafiltration membrane using ultrasonication has been carried out. The effects of different contact times, at constant frequency and power of 28 kHz and 60 Watt, respectively on membrane cleaning with and without chemical agents were studied. Results showed that the best optimal membrane cleaning achieved were sonicating in 15 minutes without any chemical agents, with 57% recoveries.It should be noted that the presence of the chemical agent increased the effectiveness of ultrasonic cleaning compared to using water. The best combination method recovered the initial flux to at 67% using 1M of NaOH and 10 min sonication. This is likely the consequence of expanded cavitations movement occurring in the more surface-dynamic result

Review on biofilm processes for wastewater treatment

This review paper discusses the application of biofilm as an alternative technology for the treatment of wastewater under various loading and operation conditions. In the past few years the biofilm technology has become more common and widely used in the world to meet the requirement for clean water sources of the world’s growing population. Besides, the conventional wastewater treatment plants like activated sludge process present some shortcomings such as not very flexible method (if there is sudden change in the character of sewage and the effluent of bad quality is obtained), so better system is urgently needed to provide additional capacity with the least possible cost and to meet the standard effluent by the local authorities. The increased incoming flow of wastewater to the treatment plants and organic loading always demand for additional treatment capacity. Fundamental research into biofilm is presented in this paper in sections that discuss the use of biofilm whereby a comparison between suspended and fixed film, old and new biofilm are made. Besides, bed types namely moving bed, fixed bed and floating bed, un-submerged fixed film systems of trickling filters and rotating biological contactors are explained. Nutrients removal of nitrogen and phosphorus and nano technology application in biofilm are also explained. Results from investigations of different applications carried out at the laboratory and pilot scales are also discussed

Forecasting a winner for Malaysian Cup 2013 using soccer simulation model

This paper investigates through soccer simulation the calculation of the probability for each team winning Malaysia Cup 2013.Our methodology used here is we predict the outcomes of individual matches and then we simulate the Malaysia Cup 2013 tournament 5000 times.As match outcomes are always a matter of uncertainty, statistical model, in particular a double Poisson model is used to predict the number of goals scored and conceded for each team.Maximum likelihood estimation is use to measure the attacking strength and defensive weakness for each team. Based on our simulation result, LionXII has a higher probability in becoming the winner, followed by Selangor, ATM, JDT and Kelantan.Meanwhile, T-Team, Negeri Sembilan and Felda United have lower probabilities to win Malaysia Cup 2013. In summary, we find that the probability for each team becominga winner is small, indicating that the level of competitive balance in Malaysia Cup 2013 is quite hig

Headmaster’s Transformational Leadership and Teacher’s Organisational Commitment in Primary School

The study aimed to explore the level of headmaster’s transformational leadership/the level of teachers/organizational commitment and the relationship between headmaster’s leadership style and the organisational commitment of primary school teachers in Beaufort, Sabah, Malaysia. The model of transformational leadership developed by Bass (1985) and the organisational commitment model which was developed by Meyer and Allen (1991) served as the theoretical framework for the study. The transformational leadership classified into inspirational motivation intellectual stimulation and individual consideration. The organisational commitment on the other hand divided into affective commitment; continuance commitment and normative commitment. Data was obtained from 130 Beauforts, primary schools teachers. The research only dealt with Grade A schools. Two questionnaires were used as the main instrument; Alimo-Metcalfe’s (2001) Transformational Leadership Questionnaire (TLQ) which consisted of 21 items and Meyer and Aliens (1997) Organisational Commitment Questionnaire (OCQ)/ which consisted of 18 items. Data was analysed with SPSS for windows version 15.0. An average positive relationship between headmaster’s inspirational motivation and teacher’s organisational commitment was found. As perceived by the teachers/ the level of headmaster’s transformational leadership in Beaufort, was high in most schools. The research also indicated that the level of teacher’s organisational commitment was average. This research also suggested numbers of ways to improve teacher’s organisational commitment

Open globe injury in Hospital Serdang - an 8-year retrospective review

Introduction: Open globe injury may lead to devastating visual outcome. Urgent management and subsequent follow-up is important to maximise recovery. More data on open globe injury in Malaysia is needed to identify risk groups and prognostic factors. This study was carried out to investigate open globe injury, the socio-epidemic profile, clinical characteristics and outcome of the open globe injury in the Hospital Serdang, Malaysia. Methods: All patients managed for open globe injury to Hospital Serdang from January 2006 to December 2013 were included in this retrospective case review. Student’s T-test was used to determine difference between means and chi-square for categorical data. P value of less than 0.05 was regarded as statistically significant. Results: There were 155 patients managed for open globe injury with three of them had bilateral involvement. As such, there were 158 cases eligible for analysis in this study. The average age was 32.2 ± 16.5 years (mean ± standard deviation, SD). Male was at higher risk for open globe injury. Predictors for poor visual outcome were foreign nationality (p=0.047), lid laceration (0.008), type of injury (p=0.001), site of injury (p=0.008), RAPD (p<0.001), uveal prolapse (p<0.001), hyphaema (p=0.008), lens damage (p=0.010), vitreous loss (0.014), retinal detachment (p=0.011), intraocular foreign body (IOFB) (0.014) and poor presenting uncorrected visual acuity (UCVA) (p<0.001). Conclusions: Occupational injury was a main cause of open globe injury in Hospital Serdang. Although in general the visual outcome is good, effort should be put to prevent work-related injury

Batch and semi-continuous biogas production from cattle manure

Anaerobic digestion of cattle manure was investigated to estimate the volume and the quality of biogas produced for both batch and semi-continuous system. The process was performed in a lab scale bioreactor at 55oC; the semi-continuous experiment was conducted at an organic loading rate (OLR) of 1.7 kg VS m-3 day-1 equivalent to hydraulic retention time (HRT) of 20 days. The volatile solid-based biogas and methane yield were observed to be averagely 0.346 m3 kg -1 VS added and 0.19 m3 kg -1 VS added respectively. The average methane content was 55% from the cattle manure during the anaerobic digestion process. Overall, the result of this study indicates that the quality of biogas obtained from the cattle wastes can be used for heat and power productio

Komunikasi mediasi komputer secara sinkronus (KMK-S) dalam proses pembelajaran bahasa Sepanyol sebagai bahasa asing

Interaksi secara autentik dalam bahasa sasaran merupakan salah satu elemen penting dalam proses pembelajaran bahasa asing. Namun demikian pelajar di Malaysia mempunyai peluang yang amat terhad untuk berinteraksi dalam bahasa asing yang dipelajari. Komunikasi Mediasi Komputer secara sinkronus (KMK-S) dijangka dapat memberi peluang kepada pelajar untuk berkomunikasi secara semulajadi dengan penutur natif di samping meningkatkan kemahiran interaktif mereka. Tujuannya adalah untuk mengalakkan kecekapan linguistik dan pragmatik mereka. Selain itu, program laman sembang khususnya dapat membantu pelajar untuk berinteraksi dengan penutur natif seperti keadaan sebenar bagaimana bahasa itu digunakan. Kajian ini dijalankan untuk mengkaji apakah persepsi pelajar terhadap penggunaan KMK-S dalam pembelajaran bahasa Sepanyol. Selain itu kajian ini akan menjelaskan apakah manfaat pedagogi terhadap penggunaan KMK-S dalam pembelajaran bahasa Sepanyol sebagai bahasa asing. Percantuman KMK-S dalam pembelajaran bahasa Sepanyol diharapkan dapat meningkatkan pendedahan dan penggunaan bahasa ini kepada pelajar

Anaerobic digestion of cattle manure: influence of inoculum concentration

This study evaluated the performance of anaerobic treatment of cattle manure (CM) with palm oil mill effluent (POME) inoculum in terms of biogas production and volatile solid (VS) reduction. The objective of the study was to determine the effect of substrate to (POME) ratio used as inoculum on digester performance. The study was conducted in a 10-L lab-scale bioreactor operated at thermophilic (53oC) temperature. The result from the study showed that anaerobic digestion of cattle manure with POME inoculum can be done successfully in batch and semi-continuous mode. Biogas production was observed to commence immediately and the POME inoculum shown a strong influence on the initial biogas production rate. Average biogas yield was estimated to be about 0.346 and 0.299 m3 kg-1 VS added for the CM(5) : POME(1.5) and CM(5) : POME(1) respectively. However, nearly similar chemical oxygen demand (COD) removal of 33% and 30% with volatile solids (VS) removal of 58.6% and 52% for the CM(5):P0ME(1.5) and CM(5):POME(1), respectively was achieved. These results are hopeful for the treatment of cattle wastes and POME mass available in Malaysia