Sodium nitroprusside, ferricyanide, nitrite and nitrate decrease the thermo-dormancy of lettuce seed germination in a nitric oxide-dependent manner in light

AbstractLettuce (L. sativa L. ‘Jianye Xianfeng No. 1’) seeds can exhibit both photodormancy and thermodormancy (thermoinhibition); however, the mechanism for thermoinhibition of seed germination is poorly understood. Here, we have investigated the response of lettuce seed germination to temperature and light, the effect of sodium nitroprusside (SNP), potassium ferricyanide (Fe(III)CN), nitrite, nitrate and NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) on the thermoinhibition of seed germination, and the inhibiting role of PTIO on SNP, Fe(III)CN, and acidified nitrite to determine the mechanisms of thermoinhibition of seed germination. Our data showed that the optimal temperature for Jianye Xianfeng No. 1 lettuce seed germination was 13–15°C in darkness, and 11–19°C in light. The thermoinhibition of seed germination could be decreased by SNP, Fe(III)CN, nitrite and nitrate in light and by nitrite and nitrate in darkness. Changes in lettuce seed germination caused by PTIO at 1–200μM were not observed at the optimal temperatures. Germination was increased by PTIO at 1–100μM and was decreased by PTIO at 200μM in light at 23°C, and that was gradually decreased by 1–200μM in darkness at 17°C. In light, SNP, Fe(III)CN and vapours produced by SNP, Fe(III)CN and acidified nitrite could effectively decrease the thermoinhibition of seed germination, and these promoting effects were inhibited by PTIO at 200μM. In darkness, nitrate and nitrite at 5 and 10mM plus PTIO stimulated the germination of seeds. Our data show that thermoinhibition of lettuce seed germination is temperature- and light-dependent, was decreased by SNP, Fe(III)CN, nitrite and nitrate in a nitric oxide-dependent manner in light

PISA and high-performing education systems: explaining Singapore's education success

Singapore’s remarkable performance in Programme for International Student Assessment (PISA) has placed it among the world’s high-performing education systems (HPES). In the literature on HPES, its ‘secret formula’ for education success is explained in terms of teacher quality, school leadership, system characteristics and educational reform. This article offers an alternative explanation for the education success of Singapore and, in so doing, questions the basic assertions of the HPES literature and, in particularly, the use of PISA results as the prime indicator of the educational performance of a school system. The explanation is informed by a historical perspective on the development of the Singapore education system and based upon a body of empirical findings on the nature of pedagogical practice in classrooms, both of which are vital for understanding the educational performance of Singapore’s education system. The article concludes by addressing the implications of this analysis for educational policy borrowing

Generation of N-qubit W state with rf-SQUID qubits by adiabatic passage

A simple scheme is presented to generate n-qubit W state with rf-superconducting quantum interference devices (rf-SQUIDs) in cavity QED through adiabatic passage. Because of the achievable strong coupling for rf-SQUID qubits embedded in cavity QED, we can get the desired state with high success probability. Furthermore, the scheme is insensitive to position inaccuracy of the rf-SQUIDs. The numerical simulation shows that, by using present experimental techniques, we can achieve our scheme with very high success probability, and the fidelity could be eventually unity with the help of dissipation.Comment: to appear in Phys. Rev.

The Singapore curriculum: Convergence, divergence, issues and challenges

In this concluding chapter we discuss how policy, programmatic and classroom curricula reflect, on the one hand, global features and tendencies, and on the other, distinct national traditions and practices. Through this examination, we relate what has been happening in Singapore to what has been happening in the world in terms of curriculum reform and globalization, and make clear how curriculum reform policy, curriculum development, and classroom enactment in Singapore have responded to globalization in distinctive ways. We conclude by identifying a set of issues, problems, and challenges that not only concern policymakers and reformers in Singapore but (which we believe) would be generally useful for policymakers, educators, and researchers in other countries

Luminous Infrared Galaxies in the Local Universe

We study the morphology and star formation properties of 159 local luminous infrared galaxy (LIRG) using multi-color images from Data Release 2 (DR2) of the Sloan Digital Sky Survey (SDSS). The LIRGs are selected from a cross-correlation analysis between the IRAS survey and SDSS. They are all brighter than 15.9 mag in the r-band and below redshift ~ 0.1, and so can be reliably classified morphologically. We find that the fractions of interacting/merging and spiral galaxies are ~ 48% and ~ 40% respectively. Our results complement and confirm the decline (increase) in the fraction of spiral (interacting/merging) galaxies from z ~1 to z ~ 0.1, as found by Melbourne, Koo & Le Floc'h (2005). About 75% of spiral galaxies in the local LIRGs are barred, indicating that bars may play an important role in triggering star formation rates > 20 M_{sun}/yr in the local universe. Compared with high redshift LIRGs, local LIRGs have lower specific star formation rates, smaller cold gas fractions and a narrower range of stellar masses. Local LIRGs appear to be either merging galaxies forming intermediate mass ellipticals or spiral galaxies undergoing high star formation activities regulated by bars.Comment: 22 pages, 5 figures, accepted for publication in ApJ, title changed, typos corrected,major revisions following referee's comments,updated reference

Helicoverpa armigera nucleopolyhedrovirus occlusion-derived virus-associated protein, HA100, affects oral infectivity in vivo but not virus replication in vitro

ORF100 (ha100) of Helicoverpa armigera nucleopolyhedrovirus (HearNPV) has been reported as one of the unique genes of group II alphabaculoviruses encoding a protein located in the occlusion-derived virus (ODV) envelope and nucleocapsid. The protein consists of 510 aa with a predicted mass of 58.1 kDa and is a homologue of poly(ADP–ribose) glycohydrolase in eukaryotes. Western blot analysis detected a 60 kDa band in HearNPV-infected HzAM1 cells starting at 18 h post-infection. Transient expression of GFP-fused HA100 in HzAM1 cells resulted in cytoplasmic localization of the protein, but after superinfection with HearNPV, GFPfused HA100 was localized in the nucleus. To study the function of HA100 further, an ha100-null virus was constructed using bacmid technology. Viral one-step growth curve analyses showed that the ha100-null virus had similar budded virus production kinetics to that of the parental virus. Electron microscopy revealed that deletion of HA100 did not alter the morphology of ODVs or occlusion bodies (OBs). However, bioassays in larvae showed that the 50% lethal concentration (LC50) value of HA100-null OBs was significantly higher than that of parental OBs; the median lethal time (LT50) of ha100-null OBs was about 24 h later than control virus. These results indicate that HA100 is not essential for virus replication in vitro. However, it significantly affects the oral infectivity of OBs in host insects, suggesting that the association HA100 with the ODV contributes to the infectivity of OBs in vivo

Genetic diversity analysis of various red spider miteresistant upland cotton cultivars based on RAPD

This study is carried out to analyze the genetic diversity of red spider mite-resistant cotton (Gossypium hirsutum) cultivars that are applied in cultivar identification and breeder's right protection of cottons. The genomic DNA was used as template and random primers were used to analyze the genetic diversity of 21 accessions of Gossypium hirsutum by RAPD-PCR. Among the 100 primers screened, 20 primers could generate 176 fragments, 96.02% of which were polymorphic ones. The similarity coefficient of cultivars was between 0.2273 - 0.9773. The average values of effective number of alleles, Nei’s gene diversity and Shannon’s information index were 1.7391, 0.4017, and 0.5773, respectively. Cluster analysis based on UPGMA revealed that 21 cultivars could be divided into three groups. The analysis revealed that it was corresponding to the geographical distribution and most of the lines had a wide genetic base.Key words: Cotton, red spider mite, RAPD, genetic diversity, cluster analysi

Transit premium and rent segmentation: A spatial quantile hedonic analysis of Shanghai Metro

When measuring the betterment effect of public transit, most of the existing econometric research tends to use residential property price data and to focus on the conditional mean rather than the conditional variance in terms of the implicit price premium paid for access to public transit. However, because property sale price partly reflects speculation on future capital gains, it sheds little light on the renters' willingness-to-pay for living near public transportation facilities, let alone the variation in rent premium for transit proximity. We in this paper employ a spatial quantile hedonic regression method to gauge the rental impact of metro stations on a large sample of two-bedroom-one-bathroom (2b1b) apartments across 2575 residential complex communities (or “xiaoqu” in mandarin Chinese) in Shanghai, China, as observed between December 2012 and January 2013. We find: a) a community’s geographic adjacency to the nearest Shanghai Metro station tends to correlate positively with the xiaoqu’s average asking rent of 2b1b apartments, indicating a significant rent premium for transit proximity; b) although the transit premium fluctuates across the different rent levels, the variation is statistically insignificant, suggesting no evidence of transit-induced segmentation of the local private residential rental market. Apart from its policy implications, this paper demonstrates a US-China comparative perspective and a novel spatial quantile regression approach to test the segmentation effect of mass transit in a dynamic urban housing market