Pan-STARRS1 DISCOVERY OF TWO ULTRALUMINOUS SUPERNOVAE AT(z) approximate to 0.9

We present the discovery of two ultraluminous supernovae (SNe) at z approximate to 0.9 with the Pan-STARRS1 Medium Deep Survey. These SNe, PS1-10ky and PS1-10awh, are among the most luminous SNe ever discovered, comparable to the unusual transients SN 2005ap and SCP 06F6. Like SN 2005ap and SCP 06F6, they show characteristic high luminosities (M-bol approximate to -22.5 mag), blue spectra with a few broad absorption lines, and no evidence for H or He. We have constructed a full multi-color light curve sensitive to the peak of the spectral energy distribution in the rest-frame ultraviolet, and we have obtained time series spectroscopy for these SNe. Given the similarities between the SNe, we combine their light curves to estimate a total radiated energy over the course of explosion of (0.9-1.4) x 10(51) erg. We find photospheric velocities of 12,000-19,000 km s(-1) with no evidence for deceleration measured across similar to 3 rest-frame weeks around light curve peak, consistent with the expansion of an optically thick massive shell of material. We show that, consistent with findings for other ultraluminous SNe in this class, radioactive decay is not sufficient to power PS1-10ky, and we discuss two plausible origins for these events: the initial spin-down of a newborn magnetar in a core-collapse SN, or SN shock breakout from the dense circumstellar wind surrounding a Wolf-Rayet star.

Effect of alkali on methylene blue (CI Basic Blue 9) and other thiazine dyes

A detailed study of the action of alkali on methylene blue (Cl. Basic Blue 9) and other thiazine dyes was carried out through a combination of UV/visible spectroscopy, thin layer chromatography, mass and NMR spectrometry and computational methods. In 0.1 M aq alkali solution, methylene blue forms a highly coloured, lipophilic species that is mainly Bernthsen's methylene violet i.e. a hydrolysis decomposition product, this being contrary to the report of a red N-hydroxy methylene blue adduct. The nature of the heterocyclic nitrogen atom in C.I. Basic Blue 9 is discussed and it is concluded there is no basis for the proposal of nucleophile addition at this site of the dye. In contrast, other thiazine dyes are deprotonated by alkali to form their neutral, highly coloured, lipophilic conjugate base forms. (C) 2010 Elsevier Ltd. All rights reserved.

The incidences of trisomy 8, trisomy 9 and D20S108 deletion in polycythaemia vera: an analysis of blood granulocytes using interphase fluorescence in situ hybridization:an analysis of blood granulocytes using interphase fluorescence in situ hybridization

We have used interphase fluorescence in situ hybridization (IFISH) to detect trisomy 8, trisomy 9 and 20q deletion in circulating granulocytes from patients with polycythaemia vera (PV). Out of 64 PV patients, 15 (23%) exhibited an abnormality. Two patients had trisomy 9, three had trisomy 8 and 10 patients had hemizygous deletion of D20S108 (a locus in the 20q common deleted region). Aberrant nuclei ranged from 10% to 80% in these 15 cases. There was no correlation between the presence of a marker and sex, age, interval between presentation and IFISH analysis, neutrophil or platelet count or therapy. Conventional marrow cytogenetic karyotype results were available in 23 cases and there was concurrence between these and blood IFISH in 16 cases (13 normal and three with 20q/D20S108 deletion by both methods). Three patients with D20S108 deletion by IFISH were normal by previous marrow cytogenetic testing and four cases with 20q deletion by previous marrow cytogenetics had normal blood granulocytes according to IFISH. Thus, we confirm that trisomies 8 and 9 and deletion of 20q are diagnostically useful markers of PV. IFISH analysis of blood granulocytes is a practical method for detecting these markers, but as an adjunct to, not as a substitute for, conventional marrow cytogenetics.

Biological effectiveness on live cells of laser driven protons at dose rates exceeding 109 Gy/s

The ultrashort duration of laser-driven multi-MeV ion bursts offers the possibility of radiobiological studies at extremely high dose rates. Employing the TARANIS Terawatt laser at Queen's University, the effect of proton irradiation at MeV-range energies on live cells has been investigated at dose rates exceeding 109 Gy/s as a single exposure. A clonogenic assay showed consistent lethal effects on V-79 live cells, which, even at these dose rates, appear to be in line with previously published results employing conventional sources. A Relative Biological Effectiveness (RBE) of 1.4±0.2 at 10% survival is estimated from a comparison with a 225 kVp X-ray source.

Cell type-dependent uptake, localization, and cytotoxicity of 1.9 nm gold nanoparticles

Background: This follow-up study aims to determine the physical parameters which govern the differential radiosensitization capacity of two tumor cell lines and one immortalized normal cell line to 1.9 nm gold nanoparticles. In addition to comparing the uptake potential, localization, and cytotoxicity of 1.9 nm gold nanoparticles, the current study also draws on comparisons between nanoparticle size and total nanoparticle uptake based on previously published data.

Methods: We quantified gold nanoparticle uptake using atomic emission spectroscopy and imaged intracellular localization by transmission electron microscopy. Cell growth delay and clonogenic assays were used to determine cytotoxicity and radiosensitization potential, respectively. Mechanistic data were obtained by Western blot, flow cytometry, and assays for reactive oxygen species.

Results: Gold nanoparticle uptake was preferentially observed in tumor cells, resulting in an increased expression of cleaved caspase proteins and an accumulation of cells in sub G1 phase. Despite this, gold nanoparticle cytotoxicity remained low, with immortalized normal cells exhibiting an LD50 concentration approximately 14 times higher than tumor cells. The surviving fraction for gold nanoparticle-treated cells at 3 Gy compared with that of untreated control cells indicated a strong dependence on cell type in respect to radiosensitization potential.

Conclusion: Gold nanoparticles were most avidly endocytosed and localized within cytoplasmic vesicles during the first 6 hours of exposure. The lack of significant cytotoxicity in the absence of radiation, and the generation of gold nanoparticle-induced reactive oxygen species provide a potential mechanism for previously reported radiosensitization at megavoltage energies.

A Randomized Controlled Trial Evaluation of Time to Read, a Volunteer Tutoring Program for 8-9 Year Olds

Tutoring is commonly employed to prevent early reading failure, and evidence suggests that it can have a positive effect. This article presents findings from a large-scale (n = 734) randomized controlled trial evaluation of the effect of Time to Read—a volunteer tutoring program aimed at children aged 8 to 9 years—on reading comprehension, self-esteem, locus of control, enjoyment of learning, and future aspirations. The study found that the program had only a relatively small effect on children’s aspirations (effect size +0.17, 95% confidence interval [0.015, 0.328]) and no other outcomes. It is suggested that this lack of evidence found may be due to misspecification of the program logic model and outcomes identified and program-related factors, particularly the low dosage of the program.

The effect of a healthy lifestyle programme on 8-9 year olds from social disadvantage

Aims: This study assessed the efficacy of a school-based healthy lifestyle intervention (Sport for LIFE) for increasing physical activity, decreasing sedentary behaviour, reducing screen time behaviour, encouraging healthy attitudes and behaviour to nutrition, and reducing body mass index (BMI) in 8–9-year-old primary school children from lower socioeconomic backgrounds in Northern Ireland.

Methods: A non-randomised controlled trial of 416 children from 24 schools took part. Schools were randomly assigned to one of two groups, an intervention or control group with 12 schools in each group. The intervention group received a 12-week school-based programme based on social cognitive theory. At baseline and follow-up, groups completed questionnaires assessing physical activity, screen time behaviour and dietary patterns. On each occasion anthropometric assessments of height and weight were taken. Physical activity and sedentary behaviour were measured by accelerometry.

Results Significant effects were observed for vigorous, moderate and light activity for the intervention group at follow-up. Sedentary behaviour was significantly reduced for the intervention group but not for the control group. No significant effects of the intervention on BMI, screen time behaviour or attitudes to nutrition, with the exception of non-core foods, were shown.

Conclusions: The programme was effective in increasing physical activity and reducing sedentary behaviour, however no significant changes in screen time behaviour and attitude to nutrition, with the exception of non-core foods, were observed. Future research ideas are offered for tackling low levels of physical activity in children.

Understanding Parental Influence on Educational Outcomes Among 9 Year Olds in Ireland: The Mediating Role of Resources, Attitudes and Children's Own Perspectives

The relationship between parental background and children's educational outcomes has been a dominant theme within the sociology of education. There has been an on-going debate as to the relative merits of explanations which focus on the role of socio-cultural reproduction and those which focus on rational choice. However, many empirical studies within the social stratification tradition fail to allow for children's own agency in shaping the relationship between social background and schooling outcomes. This paper draws on the first wave of a large-scale longitudinal study of over 8,000 nine-year-old children in Ireland, which combines information from parents, school principals, teachers and children themselves. Both social class and parental education are found to have significant effects on reading and mathematics test scores among nine year olds. These effects are partly mediated by home-based educational resources and activities, parents' educational expectations for their child, and parents' formal involvement in the school. More importantly, children's own engagement with, and attitudes to, school significantly influence their academic performance. The influence of children's own attitudes and actions can thus reinforce or mitigate the effect of social background factors. The analysis therefore provides a bridge between the large body of research on the intergenerational transmission of inequality and the emerging research and policy literature on children's rights.