Population abundance of Aedes albopictus and culex quinquefasciatus in 24 hours cycle in residential areas, penang using different trapping methods

The increasing concern on the current activity of Aedes albopictus and Culex quinquefasciatus mosquitoes as pest and diseases vector in the residential areas require thorough and immediate evaluation. Therefore, 24 hours trapping was conducted at the urban Sungai Dua and sub-urban Batu Maung residence area, Penang, Malaysia, using two different traps; BG- Sentinel Trap and CDC Fay-Prince Light Trap under two different light conditions to investigate the possibility effect of light to both mosquito species. CDC Fay-Prince light trap was effective in trapping Cx. quinquefasciatus than BG–Sentinel traps. The results indicated that both traps were ineffective to capture Ae. albopictus. In this study, the peak activity of Ae. albopictus was not following the diel host-seeking activity which this species active at daylight (6:00am–8:00am) and during night time (6:00pm–8:00pm). Whereas, Cx. quinquefasctus was captured mostly during the nocturnal time (12:00am–6:00am) with a greater number of Cx. quinquefasciatus mosquitoes captured under no light conditions. Meteorological parameter recorded within experiment such as temperature, relative humidity, and wind speed did not correlate with the abundance of both mosquito species (p> 0.05). However, light intensity parameters significantly affected Cx. quinquefasciatus mosquito abundance in both residential areas (p= 0.002), but not the Ae. albopictus mosquitoes (p= 0.086 Sungai Dua; p= 0.803 Batu Maung) as light is not a primary cue attraction factor to any host source towards this species. Ovitraps seem to be better tools for collecting and surveillance population of Ae. albopictus mosquitoes as compared to BG- Sentinel trap (Paired t-test; p= 0.019) and CDC Fay-Prince light trap (Paired t-test; p= 0.025). As a conclusion, BG-Sentinel trap and CDC Fay-Prince light traps is a not suitable tool for monitoring the activities of Ae. albopictus in the residential area, but CDC Fay-Prince light traps still found effective to use to capture Cx. quinquefasciatus. This study has therefore established immature sampling as the most effective method of capturing Ae. albopictus in a residential area

Multifarious roles of feeding behaviours in rove beetle, Paederus fuscipes

The rice green leafhopper Nephotettix virescens Distant (Hemiptera: Cicadellidae), zigzag leafhopper Recilia dorsalis Motschulsky (Hemiptera: Cicadellidae), and brown planthopper Nilaparvata lugens Stål (Hemiptera: Delphacidae) are the most economically important insect pests infesting rice crop. Paederus fuscipes Curtis has been reported as the natural predator for these rice pest species in Southeast Asia. Under laboratory conditions, we evaluated the prey preference of this generalist predator when it encountered the three main agricultural pests of rice plant. P. fuscipes typically displayed a Type II functional response for all prey species. However, at high prey densities they consumed predominantly R. dorsalis with highest attack rate on dead R. dorsalis prey. Conversely, significantly highest time was needed to handle live R. dorsalis. When various density of preys was tested simultaneously, the predator showed greater preferences towards R. dorsalis and Ni. lugens. We observed the behavioral response of P. fuscipes predator on its prey items. Highest number of searching and capturing attempt was most frequently displayed on live Ni. lugens prey species. Whereas, P. fuscipes spent more feeding time in consuming dead prey compared to the alive ones. Overall, P. fuscipes showed successful control of small and soft body crop pests at low prey density

Pembuatan Dan Uji Kualitas Bahan Bakar Alternatif(Biodiesel) Dari Minyak kelapa (Cocos nucifera)

Hasil penelitian menunjukkan bahwa minyak kelapa dapat dibuat sebagai bahan bakar alternatif (biodiesel) dan biodiesel yang dihasilkan dari minyak kelapa tersebut memiliki kualitas atau mutu yang baik sebagai bahan bakar. Hal ini didukung dari beberapa uji kualitas yang dilakukan antara lain uji kadar air, massa jenis, viskositas, bilangan asam, gliserol bebas dan gliserol total, kadar ester alkil dan angka iodium. Hasil yang didapat memenuhi Standar Nasional Indonesia untuk biodiesel

REAL-TIME CLASSIFICATION OF FACIAL EXPRESSIONS USING A PRINCIPAL COMPONENT ANALYSIS AND CONVOLUTIONAL NEURAL NETWORK

Classification of facial expressions has become an essential part of computer systems and human-computer fast interaction. It is employed in various applications such as digital entertainment, customer service, driver monitoring, and emotional robots. Moreover, it has been studied through several aspects related to the face itself when facial expressions change based on the point of view or perspective. Facial curves such as eyebrows, nose, lips, and mouth will automatically change. Most of the proposed methods have limited frontal Face Expressions Recognition (FER), and their performance decrease when handling non-frontal and multi-view FER cases.  This study combined both methods in the classification of facial expressions, namely the Principal Component Analysis (PCA) and Convolutional Neural Network (CNN) methods. The results of this study proved to be more accurate than that of previous studies. The combination of PCA and CNN methods in the Static Facial Expressions in The Wild (SFEW) 2.0 dataset obtained an accuracy amounting to 70.4%; the CNN method alone only obtained an accuracy amounting to 60.9%

Efficacy of different parts of Tridax procumbens as a potential biolarvicide against Aedes aegypti and Aedes albopictus

The epidemic of dengue and Zika outbreak transmitted by Aedes mosquitoes has been a global issue and plenty of preventive measurements are being used. Due to environmental awareness, people are opting on bioinsecticide. The objective of this research is to study on the effectiveness of different parts of Tridax procumbens plant on Aedes aegypti and Aedes albopictus larvae. Tridax procumbens are endemic plants in Malaysia. Using WHO standard larval bioassay, third instar larvae of Ae. aegypti and Ae. albopictus were exposed to different concentrations, ranging between 250ppm-2500ppm for three different parts of T. procumbens plant extracts obtained from Soxhlet extraction. Larval mortality was observed after 24-hour exposure. The highest toxicity for Ae. aegypti was recorded by T. procumbens stem extract with the LC50 of 799.78ppm. The pairwise comparison showed, the highest mean mortality value for stem did not show any significant difference with leaves; however, it did show a significant difference with flowers when tested on Ae. aegypti (P<0.05). Meanwhile for Ae. albopictus, the highest toxicity recorded with the LC50 of 583.63ppm was by the T. procumbens flower extract. The mean mortality value for flower showed significant differences from other plant parts when tested on Ae. albopictus (P<0.05). This indicates that T. procumbens is effective in killing both Ae. aegypti and Ae. albopictus

Variable selection in high dimensional data with interactions

A common research area in statistical machine learning has been variable selection in high dimensional settings. In recent years, numerous effective approaches have been created to deal with these challenges. In order to improve the prediction accuracy of the model for the given dataset, this study sought to present a double approach variable selection method when pairwise interactions between the explanatory variables exist and to choose the smallest explanatory variable set (considering interactions among them). In this study, a double step method consolidating Random Forest and Adaptive Elastic Net was further examined to mimic potential health effects of environmental contamination. When there were existing interactions in the data or none at all, the double step approach was compared to the single-step adaptive elastic net method and two-step CART paired with the adaptive elastic net method. Using significant statistical tests like RMSE, R2, and the quantity of the variable chosen for the final model, the success of the strategies was measured. The double step RF+AENET approach produces a simple, constrained model. Despite the complex association between exposure variables, it has the lowest false detection rate for null interactions. A set of variables that have correlation with the result are effectively retained by the screening and variable reduction processes in the RF step of the RF+AENET approach. The double step RF+AENET performs prediction better than a single technique and chooses a sparse model that is close to the true model. Thus, it can be said that when there are pairwise interactions between variables in the simulated biological dataset, the double step technique is a better method for model prediction and parameter estimation

Attraction factors for Paederus fuscipes ' dispersal, a vector of Paederus dermatitis towards human residential premises

Paederus fuscipes, a vector of Paederus dermatitis in most tropical and subtropical countries of the world have a high prevalence in human dwellings due to their positively phototaxic behaviour which has caused a tremendous impact on human health. In this paper, P. fuscipes dispersal flights were studied for two seasons of the rice cultivation phases in residential premises built close to rice field areas (≈32-60 m and 164 m) in mainland Penang, Malaysia. We examined the effects of different light illuminance, building floor level and their association with rice stages as a focal cause of P. fuscipes dispersion from the rice fields towards human dwellings. The present study showed a significant interaction between different light illuminances and rice cultivation phases in attracting P. fuscipes to disperse and invade human dwellings. The highest number of P. fuscipes was captured near the bright light. P. fuscipes flights increased in line with each floor level, and the highest captures took place at higher building floor levels (levels 2 and 3) compared to lower building floor levels (ground floor and level 1) of a three storey apartment in both rice seasons. This finding not only conveys a better understanding on P. fuscipes dispersal pattern, but also draws public attention on the occurrence of dermatitis linearis caused by the Paederus beetles

The Influence of Mosquito Predators on Population Dynamics of Endemic and Exotic Mosquitoes

The presence of predators can shape the population dynamics of prey. Here, I evaluated the influence of predators on mosquito populations by direct effects through predation, and indirect effects through sub-lethal responses. The predator under investigation was the backswimmer Anisops wakefieldi. I first quantified the relationship between mosquito and predator populations in animal drinking water troughs, and correlated their abundance with water volume and environmental factors. Logistic regression indicated that the presence of mosquitoes was primarily affected by three factors; predator numbers, week of observation, and water volume. A translocation experiment was established to understand the pre- and post-treatment effects on mosquito survival after exposure to the predator Anisops wakefieldi. The presence of these predators in water troughs significantly decreased subsequent survival of mosquito prey within two days posttranslocation. A major hypothesis in invasion ecology suggests that native predators have less impact on exotic species relative to native prey species, enabling exotic species to establish and thrive in novel environments. This is the "escape from natural enemies" hypothesis. Contrary to this hypothesis A. wakefieldi, a native New Zealand predator, showed a greater preference, and consumed more of the exotic mosquito Aedes (Ochleratatus) notoscriptus compared to the native (Culex pervigilans) mosquito larvae. Anisops wakefieldi exhibited a decelerating Type II functional response for both prey species, but consumed more exotic mosquito species at high prey densities and displayed higher attack rates. The effects of the preference of this predator on mosquito behaviour were examined. In the presence of predators the exotic species, Ae. notoscriptus, demonstrated significantly higher levels of "thrashing" behaviours, apparently making itself more obvious to the predators. In contrast Cx. pervigilans fulfilled the "threat sensitivity" hypothesis by altering its behaviour towards "resting", known to be the best strategy for avoiding predators. In addition to lethal effects, predators can substantially alter prey populations by means of sub-lethal influences. To further our understanding of how predators limit mosquito abundance, I developed an experiment based on adult mosquito oviposition. I predicted that the New Zealand native mosquito, Cx. pervigilans would likely avoid containers with A. wakefieldi or their kairomones. Contrary to our predictions, Cx. pervigilans appeared to ignore the presence of predators and their kairomones when choosing oviposition habitats and the number of egg rafts was not significantly affected by the density of predators. Culex pervigilans eggs from the oviposition experiment were reared in two different laboratory conditions: (A) in clean water without any traces of predators, or (B) in water with the same treatments as in field. This experiment was established in order to have better understand on what happens to the next generation after exposure to A. wakefieldi predators or their kairomones. Sub-lethal effects were still apparent in the developing larvae. I observed a significant reduction in the survival rate of Cx. pervigilans in the presence of predators and their kairomones, even when the eggs were only exposed briefly to water containing either predators or kairomones in the field, and were then reared in clean water without any traces of the predator. No effect was observed on the sex ratio of Cx. pervigilans, or the development times of each life stage. Overall, this thesis has highlighted the importance of predators in influencing mosquito populations, not only through direct predation, but also in indirect and sub-lethal ways. This study may have implications for the dynamics of other predator-prey systems. Despite this, we are only beginning to understand the complex interactions between predators and prey

Kajian Pengenalan Ekspresi Wajah menggunakan Metode PCA dan CNN

Pengenalan ekspresi wajah secara cepat menjadi bagian penting dalam sistem komputer dan interaksi antar manusia dan komputer karena cara yang paling ekspresif dalam menunjukkan emosi sebagai manusia adalah melalui ekspresi wajah. Dalam kajian ini, pengenalan eskpresi wajah dipelajari melalui beberapa aspek yang berhubungan dengan wajah itu sendiri. Ketika eskpresi wajah berubah, lekukan pada wajah seperti alis, hidung, bibir dan mulut akan otomatis berubah. Dalam kajian ini, akan dibahas mengenai sistem pengenalan ekspresi wajah secara realtime menggunakan metode PCA dan CNN. Dimana metode PCA yang akan digunakan untuk pengektraksi fitur adalah metode Eigenfaces sedangkan untuk pengklasifiksian akan menggunakan metode CN

Rancangan Perilaku Belanja Customer pada E-marketplace dengan algoritma Hybrid Improved Tabu Search untuk optimasi Association Rule Mining (FP-Growth)

Kebiasaan seseorang dalam melakukan transaksi belanja pada suatu e-marketplace mempunyai suatu pola kesamaan memilih produk yang sama. Association Rule Mining merupakan salah satu teknik  menambang data informasi yang berguna dalam mengidentifikasi kebiasaan tersebut. Kegiatan transaksi dirancang untuk mempermudah pelanggan dalam menentukan produk belanja sesuai kebutuhan  yang diinginkan dengan tujuan kenyamanan berbelanja, terutama kemudahan dalam memberi masukan relasi produk sebagai rekomendasi berdasarkan konsumen lain pada umumnya. Penelitian ini menentukan pola perilaku belanja pelanggan pada E-marketplace dengan bantuan  Hybrid Improved Particle Swarm Optimization integrasi dengan Tabu Search dan Association Rule Mining dengan algoritma FP Growth dalam menentukan kebiasaan berbelanja pelanggan