In this paper, a model called graph partitioning and transformation model (GPTM) which transforms a connected graph into a single-row network is introduced. The transformation is necessary in applications such as in the assignment of telephone channels to caller-receiver pairs roaming in cells in a cellular network on real-time basis. A connected graph is then transformed into its corresponding single-row network for assigning the channels to the caller-receiver pairs. The GPTM starts with the linear-time heuristic graph partitioning to produce two subgraphs with higher densities. The optimal labeling for nodes are then formed based on the simulated annealing technique. Experimental results support our hypothesis that GPTM efficiently transforms the connected graph into its single-row network.
The Contraves Autolyzer 801 is a 20 parameter cell counter that operates on the principle of impedance. This evaluation study found that the within-batch precision for 5 of its parameters--WBC, RBC, Hb, Hct and Plt--had coefficients of variation below 5%, while the counts for red cell parameters were reproducible for up to 3 days. The analyser exhibited good linearity for all the parameters. When compared with 2 other counters--the Coulter S-Plus and the Coulter M350, some degree of proportional and constant bias due to unsuitable calibration were detected in the WBC, Hct and Plt parameters. Otherwise it showed generally good correlation in all the parameters and also with the manual PCV method. Carry over was negligible in the red cell parameters. The Contraves Autolyzer 801 is easy to operate and readily accepted by operators.
A system for computerising full blood picture reporting developed in-house using dBASE IV on IBM-compatible microcomputers in a local area network environment is described. The software package has a user-friendly interface which consists of a horizontal main menu bar with associated pull-down submenus. The package captures data directly from an automatic blood cell counter and provides options to modify or delete records, search for records, print interim, final or cumulative reports, record differential counts with an emulator, facilitate house-keeping activities which include backing-up databases and repairing corrupted indices. The implementation of this system has helped to improve the efficiency of reporting full blood picture in the haematology laboratory.
The location model proposed in the past is a predictive discriminant rule that can classify new observations into one
of two predefined groups based on mixtures of continuous and categorical variables. The ability of location model to
discriminate new observation correctly is highly dependent on the number of multinomial cells created by the number
of categorical variables. This study conducts a preliminary investigation to show the location model that uses maximum
likelihood estimation has high misclassification rate up to 45% on average in dealing with more than six categorical
variables for all 36 data tested. Such model indicated highly incorrect prediction as this model performed badly for
large categorical variables even with large sample size. To alleviate the high rate of misclassification, a new strategy
is embedded in the discriminant rule by introducing nonlinear principal component analysis (NPCA) into the classical
location model (cLM), mainly to handle the large number of categorical variables. This new strategy is investigated
on some simulation and real datasets through the estimation of misclassification rate using leave-one-out method. The
results from numerical investigations manifest the feasibility of the proposed model as the misclassification rate is
dramatically decreased compared to the cLM for all 18 different data settings. A practical application using real dataset
demonstrates a significant improvement and obtains comparable result among the best methods that are compared. The
overall findings reveal that the proposed model extended the applicability range of the location model as previously it
was limited to only six categorical variables to achieve acceptable performance. This study proved that the proposed
model with new discrimination procedure can be used as an alternative to the problems of mixed variables classification,
primarily when facing with large categorical variables.
This study determined the effect of growth media and culture concentration on the growth, proximate, and microelement composition of Ankistrodesmus falcatus. The culture of A. falcatus was done using three media, namely Modified COMBO Medium (COMBO), Bold's Basal Medium (BBM), and Bristol, at two concentrations (50% and 100%). The results obtained show that the cell density (>3.5 × 107 cells/mL), optical density (>0.24), and specific growth rate (>0.429%/day) were significantly higher (p ≤ 0.05) in BBM and COMBO than in Bristol (<3.1 × 107 cells/mL; <0.23; <0.416%/day, respectively) at both concentrations. However, biomass was higher in BBM (>2.20 g/L) than in COMBO (1.87-2.13 g/L), while Bristol had the lowest value observed (1.70-1.73 g/L). Biochemical and microelement composition showed variations between media and at the different concentrations, with higher values observed in BBM and COMBO. Based on the growth parameters and nutritional composition, it was concluded that BBM and COMBO were better media for the propagation of A. falcatus growth than Bristol. The study also demonstrated that the microalgae can be cultured using half of the media's concentration to lower production costs.
This study describes the adaptations of diatoms, Cylindrotheca fusiformis and other marine diatoms, in a new formulated enriched medium Tris-phosphate seawater (TP-SW). The medium was designed to maintain long-term cultures of wide-range marine diatoms in laboratory that produces high biomass of cultures. The diatoms were adapted and cultivated in the medium for 15 days and the number of cells was recorded daily. It was found that the number of cells declined after two weeks indicating death phase of the cells. This indicates that the TP-SW medium has supported the growth of diatoms during the period and can be used to cultivate diatoms in vitro. Studies on the TP-SW medium must be done to obtain optimal medium that can provide not only a conducive environment for the survival of diatoms but also high biomass production.
The flow distribution of a proton exchange membrane fuel cell within a manifold plays an important role on its performance. This study presents a numerical analysis of the flow distribution behavior within different manifold configurations. A two-dimensional model with 75 cells was employed to study the flow behavior. The variation in the stoichiometry and number of cells was also studied. Three different flow configurations were considered with different numbers of flow inlets and outlets. The flow characteristics, such as the pressure and velocity variations in the manifold and cells, were measured to determine the effects of the different flow configurations. The results indicated that the double inlet/outlet configuration had the best flow distribution when using 75 cells. Moreover, increasing the stoichiometry resulted in a better flow distribution to the cells in a stack.
A novel thin-film multijunction solar cell based on nanocrystalline silicon (nc-Si:H) is presented in this paper. Existing thin-film double junction solar cells are based on amorphous silicon carbide (aSiC:H) and amorphous silicon layers. Such solar cells have limited efficiency due to lower absorption and poor charge transport properties of the a-SiC:H layer. These solar cells have maximum achieved efficiency of about 8.8%. In this work, a-SiC:H has been replaced with nc-Si:H layer and the double junction solar cell has been redesigned. The proposed structure has been simulated with Silvaco TCAD (ATLAS). The simulated results indicated a step increase in the performance of the solar cell with open circuit voltage Voc=2 .096 V and efficiency 77 = 102%. It was proven that the nc-Si:H is a suitable material for the development of an efficient thin film multijunction solar cell.
In incomplete contingency tables, some cells may contain structural zeros. The quasi-independence model, which is a generalization of the independence model, is most commonly model used to analyze incomplete contingency tables. Goodness of fit tests of the quasi-independence model are usually based on Pearson chi square test statistic and likelihood ratio test statistic. In power divergence statistics family, the selection of power divergence parameter is of interest in multivariate discrete data. In this study, a simulation study is conducted to evaluate the performance of the power divergence statistics under quasi independence model for particular power divergence parameters in terms of power values.
Tumor necrosis factor alpha (TNFα) is a multifunctional cytokine which plays a pivotal role in the pathogenesis of rheumatoid arthritis (RA). Apart from its well recognized proinflammatory properties, it is known to interfere with lipid metabolism and erythropoiesis. We evaluated the effects of adalimumab on hematologic, lipid and inflammatory parameters using data from patients on adalimumab 40 mg fortnightly from 2 centers in Malaysia. Mean changes in laboratory values from baseline to Weeks 4, 12 and 24 were compared using paired T test and Wilcoxon signed-rank test. We studied 18 patients with RA who were on adalimumab 40 mg fortnightly. The inflammatory markers i.e. erythrocyte sedimentation rate and C reactive protein showed significant changes as early as at week 4 compared to baseline with p values of 0.003 and 0.005, respectively. From a baseline of high disease activity with a mean Disease Activity Score using 28 joint counts (DAS 28) of 5.3, there was a steady improvement in the disease activity and remission was achieved at week 24 with a DAS 28 of 2.4. The hemoglobin level improved at week 12 (p=0.013) and this was sustained till week 24. As opposed to previous studies, the LDL level significantly decreased at week 12 (p=0.015) and this change persisted till week 24 (p=0.001). The total cholesterol showed a similar pattern as the LDL. The pharmacodynamics of adalimumab therapy in rheumatoid arthritis extend beyond the joints with favorable effects on haemoglobin and lipid profile.
Study site: Putrajaya Hospital and Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
Different counter electrode (CE) materials based on carbon and Cu2S were prepared for the application in CdS and CdSe quantum dot-sensitized solar cells (QDSSCs). The CEs were prepared using low-cost and facile methods. Platinum was used as the reference CE material to compare the performances of the other materials. While carbon-based materials produced the best solar cell performance in CdS QDSSCs, platinum and Cu2S were superior in CdSe QDSSCs. Different CE materials have different performance in the two types of QDSSCs employed due to the different type of sensitizers and composition of polysulfide electrolytes used. The poor performance of QDSSCs with some CE materials is largely due to the lower photocurrent density and open-circuit voltage. The electrochemical impedance spectroscopy performed on the cells showed that the poor-performing QDSSCs had higher charge-transfer resistances and CPE values at their CE/electrolyte interfaces.
Combination between tissue engineering and other fields has brought an innovation in the area of regenerative medicine which ultimate aims are to repair, improve, and produce a good tissue construct. The availability of many types of scaffold, both synthetically and naturally have developed into many outstanding end products that have achieved the general objective in tissue engineering. Interestingly, most of this scaffold emulates extracellular matrix (ECM) characteristics. Therefore, ECM component sparks an interest to be explored and manipulated. The ECM featured in human amniotic membrane (HAM) provides a suitable niche for the cells to adhere, grow, proliferate, migrate and differentiate, and could possibly contribute to the production of angiogenic micro-environment indirectly. Previously, HAM scaffold has been widely used to accelerate wound healing, treat bone related and ocular diseases, and involved in cardiovascular repair. Also, it has been used in the angiogenicity study, but with a different technical approach. In addition, both side of HAM could be used in cellularised and decellularised conditions depending on the objectives of a particular research. Therefore, it is of paramount importance to investigate the behavior of ECM components especially on the stromal side of HAM and further explore the angiogenic potential exhibited by this scaffold.
This research was conducted to evaluate the effects of supplementation of jackfruit puree on probiotic (Lactobacillus acidophilus FTDC 1295) in terms of cell count, viability and nutritional value of dadih. Four samples of dadih were prepared in this investigation; Control, Jackfruit dadih, Probiotic dadih and Jackfruit Probiotic dadih (Control, ConJD, ConPD and JPD respectively). Results revealed that dadih supplemented with jackfruit puree (JPD) directly improved the probiotic cell counts which are significantly higher than the dadih without jackfruit puree (ConPD). The high probiotic viability in dadih (ConPD 92%; JPD 96%) indicated that it can be an effective probiotic delivery vehicle. The chemical compositions (moisture, total solids, fat, protein, mineral, organic acid, and pH) showed variations in its pattern due to the differential in formulations and the incorporations of probiotic bacteria. In addition, the Total Phenolic Content and the antioxidant capacity were reported to be the highest in dadih supplemented with jackfruit puree and probiotic (JPD) as compared with other dadih samples. These are attributed by the presence of jackfruit puree and probiotic in the samples which effectively increased the total phenolic content which directly increase the antioxidant activity
Introduction: Dengue is one of the commonest infections in Malaysia and it is a notiﬁ able disease. Even
though the diagnosis of classical dengue fever and dengue haemorrhagic fever can be recognized clinically, the diagnosis remains a challenge in areas where it could not be differentiated with other febrile illnesses. The aim of this study was to focus on the speciﬁ c and consistent morphological features observed in blood ﬁ lms of dengue infection. Materials and Methods: In all 400 cases of dengue infection serologically diagnosed in the Tengku Ampuan Afzan Hospital (HTAA) during May to October 2007, only a total of 27 cases had blood ﬁ lms examined, and thus were included in this study. These blood ﬁ lms were re-examined by two pathologists from HTAA. The full blood count parameters were also retrieved and studied. Results: We consistently found typical reactive lymphocytes [n= 23 (85%)] and thrombocytopenia [n=21, (77.8%)] in the cases. However, leucopenia was present only in 9 cases (33%). Conclusion: The presence of typical reactive lymphocyte is a consistent ﬁ nding in dengue fever and thus could have a signiﬁ cant role in supporting the diagnosis of dengue infection.
For many years counting cells and identifying them under the microscope has been the conventional method to determine the number of abnormal and normal cells in cancers. During the last decade, studies have shown that the detection and quantification of residual tumor cells is important in predicting the clinical outcome of several types of hematological malignancies. Detection of
minimal residual disease (MRD) is now becoming routinely implemented in treatment protocols and is increasingly used for guiding therapy and for evaluation of new treatment modalities (Raanani & Hashomer, 2004). A wide variety of techniques have been developed to detect residual malignant cells beyond the sensitivity of conventional approaches by cell morphology. One of these technology is by real time quantitative (RQ) polymerase chain reaction (PCR) using the Taqman and LightCycler systems.
Liver perfusion has been the standard method to digest and isolate liver
cells including liver sinusoidal endothelial cells (LSEC). Poor cannulating skills through
portal vein results in a waste of animal resource. Familiarization of both liver perfusion
technique and adhering strictly to aseptic technique during cell handling ensure high
cell yield, minimum morphology disruption and cell contamination. We aimed to present
a method of liver perfusion procedure followed by the isolation of LSEC. (Copied from article).
The growth of several biological tissues is known to be controlled in part by local geometrical features, such as the curvature of the tissue interface. This control leads to changes in tissue shape that in turn can affect the tissue's evolution. Understanding the cellular basis of this control is highly significant for bioscaffold tissue engineering, the evolution of bone microarchitecture, wound healing, and tumor growth. Although previous models have proposed geometrical relationships between tissue growth and curvature, the role of cell density and cell vigor remains poorly understood. We propose a cell-based mathematical model of tissue growth to investigate the systematic influence of curvature on the collective crowding or spreading of tissue-synthesizing cells induced by changes in local tissue surface area during the motion of the interface. Depending on the strength of diffusive damping, the model exhibits complex growth patterns such as undulating motion, efficient smoothing of irregularities, and the generation of cusps. We compare this model with in vitro experiments of tissue deposition in bioscaffolds of different geometries. By including the depletion of active cells, the model is able to capture both smoothing of initial substrate geometry and tissue deposition slowdown as observed experimentally.
The issue of classifying objects into groups when measured variables in an experiment are mixed has attracted the attention of statisticians. The Smoothed Location Model (SLM) appears to be a popular classification method to handle data containing both continuous and binary variables simultaneously. However, SLM is infeasible for a large number of binary variables due to the occurrence of numerous empty cells. Therefore, this study aims to construct new SLMs by integrating SLM with two variable extraction techniques, Principal Component Analysis (PCA) and two types of Multiple Correspondence Analysis (MCA) in order to reduce the large number of mixed variables, primarily the binary ones. The performance of the newly constructed models, namely the SLM+PCA+Indicator MCA and SLM+PCA+Burt MCA are examined based on misclassification rate. Results from simulation studies for a sample size of n=60 show that the SLM+PCA+Indicator MCA model provides perfect classification when the sizes of binary variables (b) are 5 and 10. For b=20, the SLM+PCA+Indicator MCA model produces misclassification rates of 0.3833, 0.6667 and 0.3221 for n=60, n=120 and n=180, respectively. Meanwhile, the SLM+PCA+Burt MCA model provides a perfect classification when the sizes of the binary variables are 5, 10, 15 and 20 and yields a small misclassification rate as 0.0167 when b=25. Investigations into real dataset demonstrate that both of the newly constructed models yield low misclassification rates with 0.3066 and 0.2336 respectively, in which the SLM+PCA+Burt MCA model performed the best among all the classification methods compared. The findings reveal that the two new models of SLM integrated with two variable extraction techniques can be good alternative methods for classification purposes in handling mixed variable problems, mainly when dealing with large binary variables.
Two experiments were conducted to develop Acartia erythraea and Oithona brevicornis cultures: The performance of five microalgal diets to produce nauplii, copepodites and adults of A. erythraea; and the performance of the same diets to produce nauplii, copepodites and adults of O. brevicornis. The five different microalgal diets were Isochrysis galbana (IG), Chaetoceros affinis (CA), Chlorella marina (CM), Nannochloropsis oculata (NO) and mixed algae (mixture of IG, CA, CM and NO at an equal abundance to provide the exact cell density). The results indicated that the abundance of both A. erythraea and O. brevicornis was higher in tanks supplied with IG and mixed algae than the tanks supplied with CA, CM and NO. IG and mixed algal diets were statistically similar on the mean abundance for both A. erythraea and O. brevicornis. The maximum production of A. erythraea nauplii was observed on day 12 of culture period and the nauplii production decreased from day 13 onwards. The mean abundance of A. erythraea copepodites and adults increased along with time up to the end of the culture period. In the case of O. brevicornis nauplii, the maximum abundance was observed on day 9 day of culture period and the nauplii production decreased from day 10 onwards. The mean abundance of O. brevicornis copepodites and adults increased gradually from the beginning to the end of the culture period. Under the experimental conditions of this study, both IG and mixed algal diets can be recommended for the best growth performance of A. erythraea and O. brevicornis.