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The energy transfer (ET) between organic molecules and semiconductors is a crucial mechanism for enhancing the performance of semiconductor-based optoelectronic devices, but it remains undiscovered. Here, ultrafast optical pump-probe spectroscopy was utilized to directly reveal the ET between organic Alq 3 molecules and Si semiconductors. Ultrathin SiO 2 dielectric layers with a thickness of 3.2-10.8 nm were inserted between Alq 3 and Si to prevent charge transfer. By means of the ET from Alq 3 to Si, the SiO 2 thickness-dependent relaxation dynamics of photoexcited carriers in Si have been unambiguously observed on the transient reflectivity change (Δ R / R ) spectra, especially for the relaxation process on a time scale of 200-350 ps. In addition, these findings also agree with the results of our calculation in a model of long-range dipole-dipole interactions, which provides critical information for developing future optoelectronic devices.

Cultivating microalgae using municipal wastewater can treat wastewater and recover algal biofuel as an energy source. Wastewater provides necessary nutrients such as nitrogen, phosphorus, and water for microalgal growth. Due to the complexity of the components of municipal wastewater and the complex symbiotic and antagonistic relationship between microalgae and bacteria, it is necessary to select the suitable dominant bacterial species that can promote the microalgae to achieve high lipid production and algal biofuel production using municipal wastewater. Based on the microalgal growth and lipid production, we selected Photosynthetic bacteria and W4 bacteria from 13 different types of bacteria and analyzed the microbial community structure of the municipal wastewater at the end of the microalgal culture cycle. Laboratory test results showed that the amount of lipid production by Photosynthetic bacteria and W4 was 0.114 g·L -1 and 0.113 g·L -1 , which is 22.58% and 21.50% higher than the production by the control group, respectively. According to the gas chromatography (GC) analysis of the lipids, Photosynthetic bacteria and W4 bacteria exerted a relatively low influence on the composition of fatty acids of Chlorella pyrenoidosa but increased the content of monounsaturated fatty acids that improve the grade of biodiesel. The results of the analysis of microbial community structure of the municipal wastewater showed that Photosynthetic and W4 bacteria reduced the richness and diversity of bacterial communities and have the potential to become the dominant bacterial community.

Cultivating microalgae using municipal wastewater can achieve not only treatment of the wastewater but also recovery of algae for use as a biofuel energy source. Wastewater provides necessary nutrients, such as nitrogen and phosphorus, and water for microalgal growth. Because of the complexity of components of municipal wastewater, variety of adaptability, and tolerance to wastewater of different microalgal species, it is necessary to select a suitable microalgal species with high performance in lipid production and identify proper pretreatment of the wastewater to achieve high lipid production using municipal wastewater for algal biofuel production. Based on microalgal growth, lipid production, and clean-up performance of wastewater, we selected Scenedesmus obliquus wild strain and Chlorella pyrenoidosa mutant by ion beam implantation from a test group for the biofuel production. Laboratory test results showed that S. obliquus wild strain and C. pyrenoidosa mutant had respective lipid productions of 0.43 g·L -1 and 0.33 g·L -1 , with more C16-C18 fatty acids, which were suitable for biodiesel production. The pollutant removals from the wastewater by S. obliquus wild strain and C. pyrenoidosa mutant were COD, 86.4% vs. 81.8%; NH 4 + -N, 100.0% vs. 100.0%; TN, 94.3% vs. 94.9%; and TP, 93.4% vs. 94.2% respectively. The two different microalgal strains required different pretreatments. After removal of large particles, the raw wastewater could be directly used for the cultivation of S. obliquus wild strain. To grow C. pyrenoidosa mutant with municipal wastewater, pretreatment procedures including precipitation followed by filtration should be employed.

Algal biofuel has become an attractive alternative of petroleum-based fuels in the past decade. Microalgae have been proposed as a feedstock to produce biodiesel, since they are capable of mitigating CO2 emission and accumulating lipids with high productivity. This article is an overview of the updated status of biofuels, especially biodiesel production from microalgae including fundamental research, culture selection and engineering process development; it summarizes research on mathematical and life cycle modeling on algae growth and biomass production; and it updates global efforts of research and development and commercialization attempts. The major challenges are also discussed.

Growth is an important trait in animal breeding. However, the genetic effects underpinning fish growth variability are still poorly understood. QTL mapping and analysis of candidate genes are effective methods to address this issue. We conducted a genome-wide QTL analysis for growth in tilapia. A total of 10, 7 and 8 significant QTLs were identified for body weight, total length and standard length at 140 dph, respectively. The majority of these QTLs were sex-specific. One major QTL for growth traits was identified in the sex-determining locus in LG1, explaining 71.7%, 67.2% and 64.9% of the phenotypic variation (PV) of body weight, total length and standard length, respectively. In addition, a candidate gene GHR2 in a QTL was significantly associated with body weight, explaining 13.1% of PV. Real-time qPCR revealed that different genotypes at the GHR2 locus influenced the IGF-1 expression level. The markers located in the major QTL for growth traits could be used in marker-assisted selection of tilapia. The associations between GHR2 variants and growth traits suggest that the GHR2 gene should be an important gene that explains the difference in growth among tilapia species.

Background: Tilapia is the common name for a group of cichlid fishes and is one of the most important aquacultured freshwater food fish. Mozambique tilapia and its hybrids, including red tilapia are main representatives of salt tolerant tilapias. A linkage map is an essential framework for mapping QTL for important traits, positional cloning of genes and understanding of genome evolution., Results: We constructed a consensus linkage map of Mozambique tilapia and red tilapia using 95 individuals from two F1 families and 401 microsatellites including 282 EST-derived markers. In addition, we conducted comparative mapping and searched for sex-determining loci on the whole genome. These 401 microsatellites were assigned to 22 linkage groups. The map spanned 1067.6 cM with an average inter-marker distance of 3.3 cM. Comparative mapping between tilapia and stickleback, medaka, pufferfish and zebrafish revealed clear homologous relationships between chromosomes from different species. We found evidence for the fusion of two sets of two independent chromosomes forming two new chromosome pairs, leading to a reduction of 24 chromosome pairs in their ancestor to 22 pairs in tilapias. The XY sex determination locus in Mozambique tilapia was mapped on LG1, and verified in five families containing 549 individuals. The major XY sex determination locus in red tilapia was located on LG22, and verified in two families containing 275 individuals., Conclusions: A first-generation linkage map of salt tolerant tilapia was constructed using 401 microsatellites. Two separate fusions of two sets of two independent chromosomes may lead to a reduction of 24 chromosome pairs in their ancestor to 22 pairs in tilapias. The XY sex-determining loci from Mozambique tilapia and red tilapia were mapped on LG1 and LG22, respectively. This map provides a useful resource for QTL mapping for important traits and comparative genome studies. The DNA markers linked to the sex-determining loci could be used in the selection of YY males for breeding all-male populations of salt tolerant tilapia, as well as in studies on mechanisms of sex determination in fish.

Isolation and identification of the autochthonous starter from a naturally fermented meat allows control of the fermentation process and promises microbiological safety for this specialty. Thus the purpose of this study was to identify the lactic acid bacteria and coagulase-negative cocci present in a traditional Taiwanese naturally fermented ham (TNFH) and to study the microbial dynamics at different ripening stages; the approach was a combination of conventional microbiological cultivation, polymerase chain reaction-denaturing gradient gel electrophoresis and DNA sequencing. In total, twelve different strains of lactic acid bacteria and three Staphylococcus strains were identified in the TNFH samples, whereas only 5 dominant strains were observed in the TNFH samples when the DGGE as a culture-independent method was applied. The bacterial ecology on the surface of the samples was mainly characterized by the stable presence of Lactobacillus sakei and Staphylococcus saprophyticus; nonetheless Leuconostoc mesenteroides and Carnobacterium divergens were the most abundant bacteria found in the final product. These results are also agreed with the findings of the culture-independent method. In addition, Microbacterium spp., Carnobacterium spp., Enterobacter spp., Brochothrix spp., Enterococcus spp., and Bacillus spp. were also present at the beginning of the ripening, but few bacteria were found at the center of the TNFH samples during the early ripening stages. However, after 30 days of ripening, the microbial ecology at the center of the TNFH samples paralleled that of the surface. Finally, as far as we have been able to determine, our report is the first to investigate the microbiological dynamics in fermented meat products using combination of cultivation, the Harrison disc method, DGGE and DNA sequencing as the culture-dependent method. Our report is also the first to show the presence of Staphylococcus arlettae in a fermented sausage and ham product., (2009. Published by Elsevier Ltd.)

Porcine uncoupling protein-3 gene was used to study its effect on carcass and meat quality traits. The UCP3 partial translated regions in skeletal muscle from four pig breeds were sequenced and the comparison of the fragment sequences among four pig breeds showed that there were three coding-region single nucleotide polymorphisms (cSNP), of which the mutation at 842 bp of the open reading frame can result in the amino acid chang between methionine and threonine, so we selected the mutation as polymorphic site. The detection of polymorphic fragment by the technique of single strand conformation polymorphism (SSCP) and chi2 analysis among three pig breeds indicated that the distribution of three genotypes(AA, AB and BB) was significantly different between Meishan and Large White or Meishan and Landrace( P < 0.01). In addition, association analysis of UCP3 polymorphism with carcass and meat quality traits was conducted in the F2 generation from the Large White x Meishan resource family, the results with GLM analysis showed that UCP3 polymorphism has significant effect on several carcass and meat quality traits and also additive effect on some carcass and meat quality traits predominated in the resource family. It implied that UCP3 gene could be a candidate gene locus or a linked marker to a major gene, which affects the porcine carcass traits and meat quality traits significantly.