A Dynamic Quantitative Microbial Risk Assessment for Norovirus in Potable Reuse System

This study describes the results of a dynamic quantitative microbial risk assessment (QMRA) for norovirus (NoV) that was used to evaluate the relative significance of foodborne, person-to-person, and person-to-sewage-to-person transmission pathways. This last pathway was incorporated into simulated potable reuse systems to evaluate the adequacy of typical treatment trains, operational conditions, and regulatory frameworks. The results confirm that secondary and foodborne transmission dominate the overall risk calculation and that waterborne NoV likely contributes no appreciable public health risk, at least in the scenarios modeled in this study. De facto reuse with an environmental buffer storage time of at least 30 days was comparable or even superior to direct potable reuse (DPR) when compound failures during advanced treatment were considered in the model. Except during these low-probability failure events, DPR generally remained below the 10−4 annual risk benchmark for drinking water. Based on system feedback and the time-dependent pathogen load to the community\u27s raw sewage, this model estimated median raw wastewater NoV concentrations of 107–108 genome copies per liter (gc/L), which is consistent with high-end estimates in recent literature

Extra-curricular activities lead to healthy social skills among students in Malaysia

This paper discusses the benefit of extra-curricular activities in social skills among students in Malaysia. Student’s participation in extra- curricular activities can increase the social skills in terms of self-confidence, building relationship with the others, collaboration, etc. On the other hand, it can develop positive relationship outside the classroom environment and act as a catalyst for social skills. What's more, through additional curricular exercises, the creation of phenomenal human capital from the physical, passionate, otherworldly and scholarly perspective can be produced

Some properties of Potato Virus M (PVM) in Crude Sap and in Pure Preparations

A study was performed to determine some properties of the potato virus M (PVM) in crude sap and in pure preparations. In crude sap the virus was shown to have a dilution end point value of 10- 4, longevity in vitro particles sedimented as one peak with a sedimentation coefficient value of 162 s. The buoyant density in cesium chloride was 1.304 gm/cm ~ Electrophoresis in polyacrylamide gels showed that the virus possessed only one protein subunit with a molecular weight of 39,300 daltons

Fitting statistical distribution of extreme rainfall data for the purpose of simulation

In this study, several types of probability distributions were used to fit the daily torrential rainfall data from 15 monitoring stations of Peninsular Malaysia from the period of 1975 to 2007. The study of fitting statistical distribution is important to find the most suitable model that could anticipate extreme events of certain natural phenomena such as flood and tsunamis. The aim of the study is to determine which distribution fits well with the daily torrential Malaysian rainfall data. Generalized Pareto, Lognormal and Gamma distributions were the distributions that had been tested to fit the daily torrential rainfall amount in Peninsular Malaysia. First, the appropriate distribution of the daily torrential rainfall was identified within the selected distributions for rainfall stations. Then, data sets were generated based on probability distributions that mimic a daily torrential rainfall data. Graphical representation and goodness of fit tests were used in finding the best fit model. The Generalized Pareto was found to be the most appropriate distribution in describing the daily torrential rainfall amounts of Peninsular Malaysia. The outputs can be beneficial for the purpose of generating several sets of simulated data matrices that mimic the same characteristics of rainfall data in order to assess the performance of the modification method compared to classical method

Role of macrophage and associated cytokines in the regulation of breast tumour lymphovascular invasion

Lymphovascular invasion, including both blood and lymphatic vessel invasion, is an important step in tumourigenesis and is a prerequisite event in the complex process of metastasis. In breast cancer, data suggest that lymphatic vessels plays a significant role by being the major route for lymphatic vessel invasion (LVI) and that inflammatory cells, may be involved in its regulation. Macrophage, a major component of inflammatory infiltrate, has been shown to be importance in tumour growth and metastasis. The biomolecular mechanisms by which macrophage can mediate dissemination of tumour cells through the lymphatic compartment are, however, not yet fully understood. In the first part of this project, CD68 (total) and CD163 (M2 subtype) macrophages were examined in two consecutive sections of 89 full-face invasive breast cancer samples. The density and localisation of macrophages were assessed using the Chalkley-grid counting method and their association with clinicopathological variables and clinical outcome was identified. A high count of CD68 macrophages was associated with the presence of lymphatic vessel invasion (LVI) and a high microvessel density (MVD), and tumour with high microvessel densities had high expression of CD163 macrophages, confirming a role for macrophage in mediating the process of angiogenesis and metastasis via lymphatic vessels. CD68 and CD163 macrophages were not associated with disease-free or breast cancer-specific survivals. In order to elucidate previous conflicting data by our lab, suggesting that recombinant, and macrophage-induced IL-1β can mediate in vitro LVI, with patient based IHC data showing that high expression of tumour IL-1β was associated with improved disease specific survival and was not associated with LVI, it was of interest to study the expression of IL-1β signalling-related proteins including caspase-1, IL-1R I, IL-1R II, IL-1RacP, and IL-1RA. This was conducted in 1902 early stage invasive breast cancer patients, with long-term follow-up, using IHC. In addition, serum IL-1β concentration was measured in a matched subset of patients using enzyme-linked immunosorbent assay (ELISA) and expression levels examined for associations with the above proteins as well as clinicopathological criteria and patient prognosis. Although pre-requisites for IL-1 signalling pathways are present in breast tumours, tumour IL-1β expression was not strongly correlated with the expression of caspase-1, IL-1R I, IL-1R II, IL-1RacP and IL-1RA. Caspase-1, IL-1R I, IL-1R II, IL-1RacP and IL-1RA were not independent prognostic factors. The analysis of the markers stained in the current study could not provide any further elucidation of the conflict between previous in vitro and IHC studies regarding the role of IL-1β in regulating LVI. The third part of the study dealt with IHC and in vitro investigations of macrophage-associated cytokines (IL-6 and IL-10) to assess their role in regulating LVI in breast cancer. Scratch wound migration assays were conducted to examine the influence of L-6 and IL-10 on breast cancer cell migration with results showing that low concentrations of IL-6 induced migration, whereas high concentrations inhibited it. Similarly, a high concentration of IL-10 also inhibited breast cancer cell migration. In addition, the effect of these cytokines, IL-6 and IL-10, on the tumour- endothelial (blood and lymphatic) adhesive process was also studied. Static adhesion assays showed that the adhesion patterns of breast cancer cell lines to the endothelial cells did not change following pre-stimulation of either blood or lymphatic endothelial cells with either IL-6 or IL-10. Thus, in vitro data suggest that both cytokines may not play a significant role in regulating LVI other than their effect on migration. The important of IHC expression of IL-6 and IL-10 were examined in a large cohort of early stage invasive breast cancer patients. Data showed that high expressions of IL-6 and IL-10 in breast cancer tissues were not associated with the presence of LVI. A significant association was found between high expression of IL-6, and longer disease-free interval, but it was not associated with improved disease-free survival. However, high IL-10 expression was not associated with improved disease-free survival, and breast cancer-specific survival. In the final part of the project, the correlation between macrophage-associated cytokines including IL-1β, IL-6, and IL-10 and their downstream signalling elements, and target genes was assessed using Spearman’s rank correlation test. Expression data for downstream signalling elements was provided via collaboration with the Breast Pathology group. No strong correlations were observed between these cytokines. In addition, their expressions in breast cancer tissues were not strongly correlated with downstream signalling compartments, or target genes. In conclusion, macrophages seem to play an important role in regulating LVI, with such LVI being almost entirely invasion of lymphatic vessels. Macrophage and macrophage-associated cytokines (IL-6 and IL-10) have been found to potential play role in breast cancer progression, with preliminary in vitro data suggesting that this may be via tumour cell migration rather than influencing tumour-endothelial cell interaction and LVI. This project has shed some light on the role of macrophage-associated cytokines in regulating LVI however more studies are needed to determine the mechanisms whereby IL-1β, IL-6, and IL-10 regulate the progression and prognosis of breast cancer

Three Level Single Phase Photovoltaic and Wind Power Hybrid Inverter

AbstractThis paper presents a new topology of three-level single phase photovoltaic (PV) and wind power hybrid inverter. It consists of three main circuits; they are a hybrid controller circuit, a charger circuit, a pulse driver and full bridge circuit. The inverter is installed in front of Electrical Energy and Industrial Electronic Systems (EEIES) Cluster, Universiti Malaysia Perlis, Northern Malaysia. Its main energy source is a PV array and wind power generation. In this research, AC three-level waveform and square wave single phase PV and wind power hybrid inverter are developed and created by a microcontroller PIC16F627A-I/P and analyzed their performance comparisons. The result shows that the AC waveform which is formed by the PV and wind power hybrid inverter will effect on AC load rms voltage, AC current and current total harmonic distortion (CTHD), for a load of 20W 220V 50Hz AC water pump, its AC load rms voltage and current are higher when the single phase PV and wind power hybrid inverter is formed as AC square wave than as AC three-level waveform, but the CTHD is lower when the single phase PV and wind power hybrid inverter is formed as AC three-level waveform than as AC square wave

Effect of annealing temperatures on TiO2 thin films prepared by spray pyrolysis deposition method

Titanium dioxide (TiO2) nanoparticles thin film has been successfully synthesized by a spray pyrolysis deposition method by using an air compressor on a fluorine-doped tin oxide (FTO) substrate and was annealed at different temperature. TiO2 is the most common oxide as an electrode in dye sensitized solar cell (DSSC) which still has chances of improvements to increase its efficiency as an electrode. The efficiency of a DSSC was relatively low but modifications on every part of a DSSC were currently in research progress and an increase in adsorbed dye molecules was considered a potential. Thus, the influences of annealing temperature on structural and morphological properties of TiO2 have been studied using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively, while the efficiency of the films in a solar cell was studied by a solar simulator. The FESEM result showed several degrees of porosity obtained by varying the annealing temperature. The crystallinity of TiO2 investigated by XRD showed that the crystallinity of the TiO2 thin films was generally unaffected by the annealing temperature. The relationship between the properties and the efficiency of the films as an electrode was also studied

FIXED-POLE ACTIVE PI FILTER DESIGN FOR HIGH FREQUENCY NONLINEAR PLL MODELS

A Phase-locked loop (PLL) is a basic control system that attempts to produce an output waveform that can match with the input reference signal in the shortest time possible. A filter is one of the main components in the PLL blocks, and it plays a very important role to determine the range of input frequency that can ensure the system stays in a locked condition. This paper focuses on designing a fixed-pole active PI filter which is suitable for high-frequency PLL-based circuits such as those used in clock generators. As PLL is bound to fall out of lock due to the nonlinear effects from its phase detector, a new approach is introduced in this work which is to combine the linear and nonlinear control method to ensure stability. Having had the phase margin specified a priori, it is shown by simulation that the allowable range of input frequency such that the system remains locked can be expanded

Fundamental Shape Discrimination of Underground Metal Object Through One-Axis Ground Penetrating Radar (GPR) Scan

Ground Penetrating Radar (GPR) was used in this research to detect or recognize the buried objects underground. Hyperbolic signals formed by datagram of GPR after detection the buried objects which quite similar to each other in term of metal shapes. The research was tested on the metal cube and metal cylinder by using the A-scan of GPR. There are steps in this signal processing step which are pre-processing step, feature extraction, and classification process. The segmentation process hyperbolic signals were segmented one by one and normalize from the negative to positive signals. The hyperbole from the metal cylinder and metal cube that had been buried in the ground is differentiated using four features of their respective A-scans which are found the maximum value of amplitude signal graph, the number of peaks in the signals graph, skewness, and standard deviation values. Finally, the classification process used learning algorithm of Multi-Layer Perceptron (MLP) was a test on Bayesian Regulation Backpropagation (BR) was given the highest accuracy, 98.70% as a classifier to classify the metal shapes which are a metal cube and metal cylinder