摘要 :
Toxorhynchites splendens larvae are a natural predator of dengue vector mosquitolarvae, Aedes albopictus. This study was carried out to evaluate the predation rate of Tx.splendens third instar larvae on Ae. albopictus larvae in 24...
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Toxorhynchites splendens larvae are a natural predator of dengue vector mosquitolarvae, Aedes albopictus. This study was carried out to evaluate the predation rate of Tx.splendens third instar larvae on Ae. albopictus larvae in 24 h. Each predator was offered preyat a density between 10 to 50 individuals. Predation rate of Tx. splendens were also testedwith two manipulated factors; various types of container and different water volumes. Theexperiment was evaluated in man-made containers (tin cans, plastic drinking glasses andrubber tires) and natural container (bamboo stumps) which were filled with different watervolumes (full, half full, 1/4 full, and 1/8 full). The prey density and the characteristics of thecontainer were found as significant factors which influence the predation rate of Tx.splendens. The predator consumed significantly more prey at higher prey densities (40 and 50preys) compared to the lowest density (10 preys) (F=3.935, df=4, p=0.008). The resultsshowed significantly higher consumption in horizontal shaped container of rubber tire than invertical shape of bamboo stumps (F=3.100, df=3, p=0.029). However, the water volume hadno significant effect on predation rate of Tx. splendens (F=1.736, df=3, p=0.162). We generallysuggest that Tx. splendens is best to be released in discarded tires or any other containerswith horizontal shape design with wide opening since Tx. splendens can become more effectivein searching prey in this type of container design. This predator is also a suitable biocontrolcandidates to be introduced either in wet and dry seasons in Malaysia.
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摘要 :
Epoxidized natural rubber-alumina nanoparticle composites were prepared by melt compounding with an internal mixer for a constant filler loading of 10 phr. Mixer parameters such as the mixing temperature, mixing time, and rotor sp...
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Epoxidized natural rubber-alumina nanoparticle composites were prepared by melt compounding with an internal mixer for a constant filler loading of 10 phr. Mixer parameters such as the mixing temperature, mixing time, and rotor speed were screened and optimized with response surface methodology to maximize the impact strength. The parameters were selected as three independent variables and the impact strength (J/m) was selected as the response in a screening factor study. The mixing temperature and its interaction terms were identified as insignificant factors with a P value greater than 0.0500. The optimum calculated values of the tested variables (rotor speed and mixing time) for the maximum impact strength were found to be a rotor speed of 60 rpm and a mixing time of 6 min with a predicted impact strength of 208.88 J/m. These predicted optimum parameters were tested in real experiments. The final impact strength was found to be close to the predicted value of 215.84 J/m, with only a 3.33% deviation.
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摘要 :
The parasitic protozoan fauna in sixty-six anurans comprising of Duttaphrynusmelanostictus, Phrynoidis juxtaspera, Hylarana erythraea and Polypedates leucomystaxcollected from Zoo Negara Malaysia was investigated. The distribution...
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The parasitic protozoan fauna in sixty-six anurans comprising of Duttaphrynusmelanostictus, Phrynoidis juxtaspera, Hylarana erythraea and Polypedates leucomystaxcollected from Zoo Negara Malaysia was investigated. The distribution and prevalence rateof parasitic species in the digestive tract and blood were examined. Seven species of intestinalprotozoa (Opalina ranarum, Cepedea dimidiata, Nycthetorus cordiformis, Entamoebaranarum, Iodamoeba butschlii, Endamoeba blattae, and Tritrichomonas sp.) and two speciesof blood protozoa (Lankesterella sp. and Trypanosoma sp.) were recorded. Opalina ranarumwas the most common protozoan found in the rectum and intestine (prevalence rate: 34.8%)infecting all host species, with P. juxtaspera heavily infected with the parasite, whereasTritrichomonas sp. was the least prevalent intestinal species infecting only D. melanostictus.Both Lankesterella sp. and Trypanosoma sp. were found in the blood of H. erythraea.
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