Invasion History of the Oriental Fruit Fly, Bactrocera dorsalis, in the Pacific-Asia Region: Two Main Invasion Routes

The oriental fruit fly, Bactrocera dorsalis, was initially recorded in Taiwan Island in 1912, and has dispersed to many areas in the Pacific-Asia region over the last century. The area of origin of the species may be confidently placed in South-East China. However, routes of range expansion to new areas and underlying population processes remain partially unclear, despite having been the subject of several studies. To explore the invasion history of this species, a partition of the cox1 gene of mitochondrial DNA was used to investigate genetic diversity, haplotype phylogeny and demographic history of 35 populations, covering China and South-East Asia and including marginal populations from Pakistan and Hawaii. Based on neighbor-joining tree analysis and the distribution of haplotypes, two main invasion routes are inferred: one from South-East China to Central China, another from South-East China to South-East Asia, with both routes probably coinciding in Central China. Populations in Taiwan Island and Hainan Island might have originated in South-East China. The marginal populations in Pakistan and Hawaii might have undergone founding events or genetic bottlenecks. Possible strategies for the control of this species are proposed based on the invasion history and reconstructed expansion routes

The Oriental Fruit Fly, Bactrocera dorsalis, in China: Origin and Gradual Inland Range Expansion Associated with Population Growth

The oriental fruit fly, Bactrocera dorsalis, expanded throughout mainland China in the last century to become one of the most serious pests in the area, yet information on this process are fragmentary. Three mitochondrial genes (nad1, cytb and nad5) were used to infer the genetic diversity, population structure and demographic history of the oriental fruit fly from its entire distribution range in China. High levels of genetic diversity, as well as a significant correspondence between genetic and geographic distances, suggest that the invasion process might have been gradual, with no associated genetic bottlenecks. Three population groups could be identified, nevertheless the overall genetic structure was weak. The effective number of migrants between populations, estimated using the coalescent method, suggested asymmetric gene flow from the costal region of Guangdong to most inland regions. The demographic analysis indicates the oriental fruit fly underwent a recent population expansion in the Central China. We suggest the species originated in the costal region facing the South China Sea and gradually expanded to colonize mainland China, expanding here to high population numbers

A Novel Buffer Tank to Attenuate the Peak Flow of Runoff

Impermeable pavements and roofs in urban areas convert most rainfall to runoff, which is commonly discharged to local sewers pipes and finally to the nearby streams and rivers. In case of heavy rain, the peak flow of runoff usually exceeds the carrying capacity of the local sewer pipes, leading to urban flooding. Traditional facilities, such as green roofs, permeable pavements, soakaways, rainwater tanks, rain barrels, and others reduce the runoff volume in case of a small rain but fail in case of a heavy rain. Here we propose a novel rainwater buffer tank to detain runoff from the nearby sealed surfaces in case of heavy rain and then to discharge rainwater from an orifice at the tank’s bottom. We found that considering a 100m2 rooftop with 0.80 runoff coefficient and a 10cm rainfall depth for an hour, a cubic tank with internal edge side of a square of 2 m attenuates the peak flow about 45%. To reduce a desirable peak flow, the outlet orifice of the buffer tank must be optimized according to site-specific conditions. The orifice can be set at an elevation from the tank’s bottom to create a dead storage for harvesting rainwater

Lowering emissivity of concrete roof tile\u27s underside cuts down heat entry to the building

Buildings in Southern China widely use a double-skin roof to reduce heat entry through the roof to the building interior during summertime. Concrete roof tiles are preferably installed as the outmost layer of the double-skin roof due to their resistance to hail and wind damages and their attractive price. However, after construction, the tile’s top tends to be darkened by dust deposit and algae growth, increasing the heat entry through the roof to the building. Here, we show that this heat entry can be curtailed by lowering the emissivity at the tile’s underside. Temperatures and heat fluxes at different elevations of a double-skin roof with concrete tiles as the outmost layer of the roof are monitored. The underside of each concrete tile is coated with a specific paint to get a unique emissivity. Observations reveal that lowering the emissivity of concrete roof tiles could cut down the summer heat gain of buildings in tropical regions

A review of research progress on mechanisms of peritoneal fibrosis related to peritoneal dialysis

Peritoneal dialysis (PD) is an effective alternative treatment for patients with end-stage renal disease (ESRD) and is increasingly being adopted and promoted worldwide. However, as the duration of peritoneal dialysis extends, it can expose problems with dialysis inadequacy and ultrafiltration failure. The exact mechanism and aetiology of ultrafiltration failure have been of great concern, with triggers such as biological incompatibility of peritoneal dialysis solutions, uraemia toxins, and recurrent intraperitoneal inflammation initiating multiple pathways that regulate the release of various cytokines, promote the transcription of fibrosis-related genes, and deposit extracellular matrix. As a result, peritoneal fibrosis occurs. Exploring the pathogenic factors and molecular mechanisms can help us prevent peritoneal fibrosis and prolong the duration of Peritoneal dialysis

An ABC Algorithm with Recombination

Artificial bee colony (ABC) is an efficient swarm intelligence algorithm, which has shown good exploration ability. However, its exploitation capacity needs to be improved. In this paper, a novel ABC variant with recombination (called RABC) is proposed to enhance the exploitation. RABC firstly employs a new search model inspired by the updating equation of particle swarm optimization (PSO). Then, both the new search model and the original ABC model are recombined to build a hybrid search model. The effectiveness of the proposed RABC is validated on ten famous benchmark optimization problems. Experimental results show RABC can significantly improve the quality of solutions and accelerate the convergence speed