Linkage and mapping analyses of the no glue egg gene Ng in the silkworm (Bombyx mori L.) using simple sequence repeats (SSR) markers

In the silkworm, Bombyx mori, no glue egg is mainly controlled by Ng (No glue) gene, which is located on the 12th chromosome. Owning to a lack of crossing over in females, reciprocal backcrossed F1 (BC1) progenies were used for linkage analysis and mapping of the Ng gene based on the simple sequence repeats (SSR) linkage map using silkworm strains H9 and P50, which are Ng mutant and normal to egg, respectively. The Ng gene was found to be linked to three SSR markers. Using a reciprocal BC1M cross, we constructed a linkage map of 36.4 cM, with Ng mapped at 15.9 cM and the nearest SSR marker at a distance of 7.4 cM. Based on fine genome map of domesticated silkworm (B. mori), the result of Kaikoblast show that the physical distance between the near markers (containing Ng gene) is 181.7 Kb. Further analysis show that BGIBMGA005833, BGIBMGA005835 and BGIBMGA005836 are closer to Ng, and the BGIBMGA005835 is nearest to Ng, which physical distance is 44 Kb.Key words: Gene location, linkage analysis, microsatellite, Ng, silkworm

Building ventilation as an effective disease intervention strategy on a large and dense social contact network

published_or_final_versio

Economic dispatch savings in the coal-fired power sector: an empirical study of China

© 2018 The current equal share dispatch approach has often been criticized for its negative influence on the electricity system operation in China, which worsens the energy security, environmental sustainability and affordability problems. To provide references for the on-going electricity market reform, this study employs an optimization model to quantify the economic dispatch savings in the coal-fired power sector. Key findings are summarized as follows: (1) The heat rates of 2803 coal generators in China range from 273.91 gce/kWh to 348.38 gce/kWh units in 2014, and the great differences among these generators at different geographical areas exhibit the necessity for economic dispatch. (2) 5.67% of the coal used for power generation could be saved from economic dispatch in a provincial level, the monetary value of which can reduce the average electricity price by 0.0058 yuan/kWh in 2014. (3) Three major political and economic challenges hinder the transition from the current dispatch mode to economic dispatch, namely the insufficient running hours for cost recovery, limited cross-border trading due to electricity over-supply and local protectionism, and the political economy problems from generators of different ownership types.This work was supported by China's National Key R&D Program (2016YFA0602603), National Natural Science Foundation of China (Nos. 71521002, 71273031 and 71573013) and China Scholarship Council (CSC) (201501310015)

Investment in carbon dioxide capture and storage combined with enhanced water recovery

Carbon dioxide capture and storage combined with enhanced deep saline water recovery (CCS-EWR) is a potential approach to mitigate climate change. However, its investment has been a dilemma due to high costs and various uncertainties. In this study, a trinomial tree modelling-based real options approach is constructed to assess the investment in CCS-EWR retrofitting for direct coal liquefaction in China from the investor perspective. In this approach, the uncertainties in CO2 prices, capital subsidies, water resource fees, the residual lifetime of direct coal liquefaction plants, electricity prices, CO2 and freshwater transport distance, and the amount of certified emission reductions (CERs) are considered. The results show that the critical CER price for CCS-EWR retrofits is 7.15 Chinese yuan per ton (CNY/ton) higher than that (141.95 CNY/ton) for CCS retrofits. However, the exemption from water resource fees for freshwater recovered from saline water and a subsidy of 26% of the capital cost are sufficient to eliminate the negative impact of enhanced deep saline water recovery (EWR) on the investment economy of CCS-EWR. In addition, when the residual lifetime is less than 14 years, CCS-EWR projects are still unable to achieve profitability, even with flexible management and decision making; therefore, investors should abandon CCS-EWR investments. On the whole, the investment feasibility for CCS-EWR technology is not optimistic despite access to preferential policies from the government. It is necessary to establish a carbon market with a high and stable CER price

Social contacts and the locations in which they occur as risk factors for influenza infection

The interaction of human social behaviour and transmission is an intriguing aspect of the life cycle of respiratory viral infections. Although age-specific mixing patterns are often assumed to be the key drivers of the age-specific heterogeneity in transmission, the association between social contacts and biologically confirmed infection has not previously been tested at the individual level. We administered a questionnaire to participants in a longitudinal cohort survey of influenza in which infection was defined by longitudinal paired serology. Using a variety of statistical approaches, we found overwhelming support for the inclusion of individual age in addition to contact variables when explaining odds of infection: the best model not including age explained only 15.7% of the deviance, whereas the best model with age explained 23.6%. However, within age groups, we did observe an association between contacts, locations and infection: median numbers of contacts (or locations) reported by those infected were higher than those from the uninfected group in every age group other than the youngest. Further, we found some support for the retention of location and contact variables in addition to age in our regression models, with excess odds of infection of approximately 10% per additional 10 contacts or one location. These results suggest that, although the relationship between age and incidence of respiratory infection at the level of the individual is not driven by self-reported social contacts, risk within an age group may be.published_or_final_versio

Learning environments research in English classrooms

Although learning environments research has thrived for decades in many countries and school subjects, English classroom environment research is still in its infancy. This article paves the way for expanding research on English classroom environments by (1) reviewing the limited past research in English classrooms and (2) reporting the first study of English learning environments in Singaporean primary schools. For a sample of 441 grade 6 students, past research in other subjects was replicated in that a modified version of the What Is Happening In this Class? questionnaire was cross-validated, classroom environment was found to vary with the determinants of student sex and ethnicity, and associations emerged between students’ attitudes and the nature of the classroom environment

A novel mechanistic model for nitrogen removal in algal-bacterial photo sequencing batch reactors

© 2018 Elsevier Ltd A comprehensive mathematical model was constructed to evaluate the complex substrate and microbial interaction in algal-bacterial photo sequencing batch reactors (PSBR). The kinetics of metabolite, growth and endogenous respiration of ammonia oxidizing bacteria, nitrite oxidizing bacteria and heterotrophic bacteria were coupled to those of microalgae and then embedded into widely-used activated sludge model series. The impact of light intensity was considered for microalgae growth, while the effect of inorganic carbon was considered for each microorganism. The integrated model framework was assessed using experimental data from algal-bacterial consortia performing sidestream nitritation/denitritation. The validity of the model was further evaluated based on dataset from PSBR performing mainstream nitrification. The developed model could satisfactorily capture the dynamics of microbial populations and substrates under different operational conditions (i.e. feeding, carbon dosing and illuminating mode, light intensity, influent ammonium concentration), which might serve as a powerful tool for optimizing the novel algal-bacterial nitrogen removal processes

Beating the channel capacity limit for linear photonic superdense coding

Dense coding is arguably the protocol that launched the field of quantum communication. Today, however, more than a decade after its initial experimental realization, the channel capacity remains fundamentally limited as conceived for photons using linear elements. Bob can only send to Alice three of four potential messages owing to the impossibility of carrying out the deterministic discrimination of all four Bell states with linear optics, reducing the attainable channel capacity from 2 to log_2 3 \approx 1.585 bits. However, entanglement in an extra degree of freedom enables the complete and deterministic discrimination of all Bell states. Using pairs of photons simultaneously entangled in spin and orbital angular momentum, we demonstrate the quantum advantage of the ancillary entanglement. In particular, we describe a dense-coding experiment with the largest reported channel capacity and, to our knowledge, the first to break the conventional linear-optics threshold. Our encoding is suited for quantum communication without alignment and satellite communication.Comment: Letter: 6 pages, 4 figures. Supplementary Information: 4 pages, 1 figur

Detection of Ligation Products of DNA Linkers with 5′-OH Ends by Denaturing PAGE Silver Stain

To explore if DNA linkers with 5′-hydroxyl (OH) ends could be joined by commercial T4 and E. coli DNA ligase, these linkers were synthesized by using the solid-phase phosphoramidite method and joined by using commercial T4 and E. coli DNA ligases. The ligation products were detected by using denaturing PAGE silver stain and PCR method. About 0.5–1% of linkers A–B and E–F, and 0.13–0.5% of linkers C–D could be joined by T4 DNA ligases. About 0.25–0.77% of linkers A–B and E–F, and 0.06–0.39% of linkers C–D could be joined by E. coli DNA ligases. A 1-base deletion (-G) and a 5-base deletion (-GGAGC) could be found at the ligation junctions of the linkers. But about 80% of the ligation products purified with a PCR product purification kit did not contain these base deletions, meaning that some linkers had been correctly joined by T4 and E. coli DNA ligases. In addition, about 0.025–0.1% of oligo 11 could be phosphorylated by commercial T4 DNA ligase. The phosphorylation products could be increased when the phosphorylation reaction was extended from 1 hr to 2 hrs. We speculated that perhaps the linkers with 5′-OH ends could be joined by T4 or E. coli DNA ligase in 2 different manners: (i) about 0.025–0.1% of linkers could be phosphorylated by commercial T4 DNA ligase, and then these phosphorylated linkers could be joined to the 3′-OH ends of other linkers; and (ii) the linkers could delete one or more nucleotide(s) at their 5′-ends and thereby generated some 5′-phosphate ends, and then these 5′-phosphate ends could be joined to the 3′-OH ends of other linkers at a low efficiency. Our findings may probably indicate that some DNA nicks with 5′-OH ends can be joined by commercial T4 or E. coli DNA ligase even in the absence of PNK

Experimental study of temperature effect on the mechanical tensile fatigue of hydrated lime modified asphalt concrete and case application for the analysis of climatic effect on constructed pavement

Previous experimental studies have suggested that hot mixed asphalt (HMA) concrete using hydrated lime (HL) to partially replace the conventional limestone dust filler at 2.5% by the total weight of all aggregates showed an optimum improvement on several key mechanical properties, fatigue life span and moisture susceptibility. However, so far, the knowledge of the thermal response of the modified asphalt concrete and thermal influence on the durability of the pavement constructed are still relatively limited but important to inform pavement design. This paper, at first, reports an experimental study of the tensile fatigue life of HMA concrete mixes designed for wearing layer application. Tests were conducted under three different temperatures for five mixes of different HL contents and one with no use of HL. On the experimental data, temperature effect on material fatigue was characterized in terms of the S-N curve modelling parameters. At last, numerical modelling, set at a climatic scenario in the UK, was performed to analyse and compare the seasonal climatic thermal influence on the fatigue life of two pavement structures using and not using the HL modified HMA concrete. Both the experiment and modelling have demonstrated that the 2.5% HL HMA concrete largely enhances the fatigue life of the material and the constructed pavement