The dominant Anopheles vectors of human malaria in the Asia-Pacific region: occurrence data, distribution maps and bionomic précis

<p>Abstract</p> <p>Background</p> <p>The final article in a series of three publications examining the global distribution of 41 dominant vector species (DVS) of malaria is presented here. The first publication examined the DVS from the Americas, with the second covering those species present in Africa, Europe and the Middle East. Here we discuss the 19 DVS of the Asian-Pacific region. This region experiences a high diversity of vector species, many occurring sympatrically, which, combined with the occurrence of a high number of species complexes and suspected species complexes, and behavioural plasticity of many of these major vectors, adds a level of entomological complexity not comparable elsewhere globally. To try and untangle the intricacy of the vectors of this region and to increase the effectiveness of vector control interventions, an understanding of the contemporary distribution of each species, combined with a synthesis of the current knowledge of their behaviour and ecology is needed.</p> <p>Results</p> <p>Expert opinion (EO) range maps, created with the most up-to-date expert knowledge of each DVS distribution, were combined with a contemporary database of occurrence data and a suite of open access, environmental and climatic variables. Using the Boosted Regression Tree (BRT) modelling method, distribution maps of each DVS were produced. The occurrence data were abstracted from the formal, published literature, plus other relevant sources, resulting in the collation of DVS occurrence at 10116 locations across 31 countries, of which 8853 were successfully geo-referenced and 7430 were resolved to spatial areas that could be included in the BRT model. A detailed summary of the information on the bionomics of each species and species complex is also presented.</p> <p>Conclusions</p> <p>This article concludes a project aimed to establish the contemporary global distribution of the DVS of malaria. The three articles produced are intended as a detailed reference for scientists continuing research into the aspects of taxonomy, biology and ecology relevant to species-specific vector control. This research is particularly relevant to help unravel the complicated taxonomic status, ecology and epidemiology of the vectors of the Asia-Pacific region. All the occurrence data, predictive maps and EO-shape files generated during the production of these publications will be made available in the public domain. We hope that this will encourage data sharing to improve future iterations of the distribution maps.</p

Land-based poly-eco-aquaculture of abalone and seaweed in a small scale recirculating system using a recycled freezer container

To minimize environmental problems associated with aquaculture, we wanted to develop an abalone and seaweed polyculture approach in a small scale recirculating aquaculture system housed in an air-conditioned recycled freezer container. We conducted two experiments; each used two recirculating systems. Each system consisted of two biofilters and two abalone culture tanks. Each abalone culture tank contained three plastic baskets for abalone. In the first experiment one of the systems also incorporated a protein skimmer (PS) to evaluate its effects on water quality and abalone growth. In the second experiment, the same system was incorporated with both a PS and a seaweed culture tank (PSS) to evaluate their combined effects on water quality and abalone growth. The abalone stocking density was 20 individuals (average weight 5.3-0.08 g and 8.7-1.9 g in the first and second experiment) per basket. Pelleted artificial feed was supplied six days per week at 2.3% of abalone body weight per day. The pH, dissolved oxygen (DO), total inorganic nitrogen (TIN), total inorganic phosphorus (TIP), and bacterial abundance were monitored daily. The duration of first and second experiments were 87 and 70 days. DO concentration was significantly higher in the system with the PS. An opposite trend was observed in TIN concentration and bacterial abundance. PS had no effect on pH or TIP. PSS influenced water quality parameters and bacterial abundance similar to PS except TIP, which was greater in the system with PSS than without. Treatment effects on growth, feed consumption, and FCR were similar in both experiments. Abalone consumed less feed and had significantly higher FCR and lower growth rates in the control. However, feed consumption, FCR and growth rate of abalone were comparatively better in the PSS system than in the PS system. The PSS system was not only better for abalone growth, but also produced an additional crop in the form of seaweed. The system did not discharge waste. Therefore, future abalone culture systems can be focused on this model. However, more research is necessary before extrapolating results to an industrial level

Effects of protein skimming on water quality, bacterial abundance and abalone growth in land based recirculating aquaculture systems

Recirculating aquaculture systems can reduce many challenges associated with open culture systems but maintaining suitable water quality in recirculating system is difficult. Protein skimmer removes organic matter from the water before it breaks down into nitrogenous waste. Therefore, the aim of this study was to evaluate the effects of protein skimming on water quality, bacterial abundance and abalone growth in recirculating aquaculture system. Two recirculating systems utilizing artificial seawater were housed in an air-conditioned, insulated recycle frozen container (4.3×1.9×1.9 m) to maintain optimum water temperature (19.2 0.80C) for abalone growth. Each system consisted of two biofilters (100 and 200 L) and two abalone culture tanks (each 200 L) containing three plastic baskets (each 50 × 34 × 6 cm, with 12 mm mesh). One culture system incorporated a protein skimmer. Over an experimental period of 87 days, protein skimming resulted in significantly better water quality, heterotrophic bacterial abundance and abalone growth. Results indicate recirculating abalone culture systems with protein skimmer housed in an air-conditioned, insulated recycle frozen container may provide a viable alternative to current land-based, flow-through systems. More research is needed to further increase the efficiency of this system

Land based abalone culture in re-circulating systems using a recycled freezer container

To minimize environmental problems associated with aquaculture, we wanted to develop abalone culture approach in small scale re-circulating aquaculture system housed in an air-conditioned recycled freezer container. Protein skimmer (PS) removes organic matter from the water before it breaks down into nitrogenous waste. The aim of this study was to elucidate the effects of PS, shelter and feeding interval on water quality, bacteria count and feed intake, feces excretion, growth and FCR of hybrid abalone (Haliotis discus hannai x H. sieboldi) in a small scale re-circulating system. A frozen container (4.3x1.9x1.9m) was used to maintain optimum water temperature at 19.2±0.8℃ for abalone growth for 87 days. Each system consisted of two bio-filters (100 and 200L) and two abalone culture tanks (each 200L) containing three plastic baskets (50x34x6cm, with 12mm mesh). The abalone stocking density was 20 individuals (5.3±0.8g). PS increased feed intake and shell growth of abalone. Shelter increased abalone growth and FCR. Feed intake was highest at a pattern of 2 days feeding after 1 day none feeding. Results indicate re-circulating abalone culture systems with PS housed in an air-conditioned recycle frozen container may provide a viable alternative to land based, flow through systems

Landbased poly-eco-aquaculture of abalone and seaweed in the small scale recirculating system using the recycled frozen container

To minimize environmental problems associated with aquaculture, we wanted to develop an abalone and seaweed polyculture approach in a small scale recirculating aquaculture system housed in an air-conditioned recycled freezer container. We conducted two experiments; each used two recirculating systems. Each system consisted of two biofilters and two abalone culture tanks. Each abalone culture tank contained three plastic baskets for abalone. In the first experiment one of the systems also incorporated a protein skimmer (PS) to evaluate its effects on water quality and abalone growth. In the second experiment, the same system was incorporated with both a PS and a seaweed culture tank (PSS) to evaluate their combined effects on water quality and abalone growth. The abalone stocking density was 20 individuals (average weight 5.3-0.08 g and 8.7-1.9 g in the first and second experiment) per basket. Pelleted artificial feed was supplied six days per week at 2.3% of abalone body weight per day. The pH, dissolved oxygen (DO), total inorganic nitrogen (TIN), total inorganic phosphorus (TIP), and bacterial abundance were monitored daily. The duration of first and second experiments were 87 and 70 days. DO concentration was significantly higher in the system with the PS. An opposite trend was observed in TIN concentration and bacterial abundance. PS had no effect on pH or TIP. PSS influenced water quality parameters and bacterial abundance similar to PS except TIP, which was greater in the system with PSS than without. Treatment effects on growth, feed consumption, and FCR were similar in both experiments. Abalone consumed less feed and had significantly higher FCR and lower growth rates in the control. However, feed consumption, FCR and growth rate of abalone were comparatively better in the PSS system than in the PS system. The PSS system was not only better for abalone growth, but also produced an additional crop in the form of seaweed. The system did not discharge waste. Therefore, future abalone culture systems can be focused on this model. However, more research is necessary before extrapolating results to an industrial level

Antifungal activity of extracts and phenolic compounds from Barringtonia racemosa L. (Lecythidaceae)

The antifungal activity of methanolic, ethanolic and boiling water extracts of Barringtonia racemosa leaves, sticks and barks were investigate against Fusarium sp., Tricoderma koningii, Penicillium sp.,Ganoderma tropicum, Ganoderma lucidum, Aspergillus sp. and Rhizopus sp. at concentration of 50 mg/ml. Better antifungal activity was observed with the methanolic extracts in all aerial parts of B.racemosa that showed excellent inhibitory activity against all the fungi tested. The strongest inhibitory activity effect was observed with the methanolic extract of leaf against Fusarium sp. (53.45%), G.lucidum (34.57%), Aspergillus sp. (32.27%) and T. koningii (20.99%). Remarkable are also the specific effects of the boiling water extract of leaf against Fusarium sp. (51.72%) and with the ethanolic extractof bark against Rhizopus sp. (37.50%). None of the boiling water extracts of leaf, stick and bark showed inhibitory activity effect against G. tropicum and T. koningii. Among different fungi tested, Fusarium sp.was found to be more sensitive to B. racemosa extracts when compared to others. The increase in the production of phenolics in the extracts can be correlated with the induction of resistance in treatedplant against phytopathogenic fungi. HPLC analysis of the extract of B. racemosa (leaves, sticks and barks) showed two different phenolic acids (gallic acid and ferrulic acid) and four different flavonoids(naringin, rutin, luteolin and kaempferol). The results of present study provide scientific basis for the use of the plant extract in the future development as antifungal, antibacterial, antioxidant and antiinflammatory agent

Determination of filler content for natural filler polymer composite by thermogravimetric analysis

© 2015 Akadémiai Kiadó, Budapest, Hungary. Determination of filler content by thermogravimetric (TG) analysis is commonly utilized to investigate the effectiveness of processing methods for composite materials and to quantify the dispersion of filler within the matrix. However, the existing analysis method is not capable of accurately predicting the filler content for natural fiber composites for the case where thermal degradation of the filler and matrix occurs within similar temperature ranges. In the present study, the authors have proposed a generic equation for the determination of filler content which can be utilized for any given range of thermal degradation temperatures in natural filler polymer composites. Oil palm shell unsaturated polyester composites were selected to verify the proposed equation using the TG test with the results indicating good agreement between the estimated and experimental filler contents with a maximum error on the order of 10 %. The suggested technique provides a simple, yet generic, approach to determining the filler content of green or lignocellulose-based polymer composites by TG analysis