Autographa californica multiple nucleopolyhedrovirus ODV-E56 envelope protein is required for oral infectivity and can be substituted functionally by Rachiplusia ou multiple nucleopolyhedrovirus ODV-E56

he Autographa californica multiple nucleopolyhedrovirus (AcMNPV) odv-e56gene encodes an occlusion-derived virus (ODV)-specific envelope protein, ODV-E56. In a previous analysis, the odv-e56 gene was found to be under positive selection pressure, suggesting that it may be a determinant of virus host range. To assess the role of ODV-E56 in oral infectivity and host range, we constructed recombinant AcMNPV clones (Ac69GFP-e56lacZ and AcIEGFP-e56lacZ) in which ODV-E56 protein synthesis was eliminated by inserting a β-galactosidase (lacZ) expression cassette into the odv-e56 open reading frame. We also constructed a recombinant virus, Ac69GFP-Roe56, in which the native AcMNPV odv-e56 coding sequence was replaced with that of Rachiplusia oumultiple nucleopolyhedrovirus (RoMNPV), a closely related virus that is significantly more virulent towards some host species than AcMNPV. The odv-e56 recombinant viruses exhibited no alterations in polyhedron production and morphogenesis or in the production of infectious budded virus in cell culture. In bioassays using three lepidopteran host species, the oral infectivities of the odv-e56 mutant viruses Ac69GFP-e56lacZ and AcIEGFP-e56lacZ were profoundly impaired compared with those of wild-type and control recombinant viruses. Oral infectivity was restored fully by marker rescue of the odv-e56 mutant viruses with either the AcMNPV or the RoMNPVodv-e56 gene. In bioassays using two host species that are more susceptible to RoMNPV than to AcMNPV, Ac69GFP-Roe56 killed larvae with LC50 values similar to those of recombinant viruses expressing AcMNPV ODV-E56. This result indicated that replacement of the AcMNPV odv-e56 gene with the RoMNPV orthologue did not increase virulence against these two species

Experts on e-learning: insights gained from listening to the student voice!

The Student Experience of e-Learning Laboratory (SEEL) project at the University of Greenwich was designed to explore and then implement a number of approaches to investigate learners’ experiences of using technology to support their learning. In this paper members of the SEEL team present initial findings from a University-wide survey of nearly a 1000 students. A selection of 90 ‘cameos’, drawn from the survey data, offer further insights into personal perceptions of e-learning and illustrate the diversity of students experiences. The cameos provide a more coherent picture of individual student experience based on the totality of each person’s responses to the questionnaire. Finally, extracts from follow-up case studies, based on interviews with a small number of students, allow us to ‘hear’ the student voice more clearly. Issues arising from an analysis of the data include student preferences for communication and social networking tools, views on the ‘smartness’ of their tutors’ uses of technology and perceptions of the value of e-learning. A primary finding and the focus of this paper, is that students effectively arrive at their own individualised selection, configuration and use of technologies and software that meets their perceived needs. This ‘personalisation’ does not imply that such configurations are the most efficient, nor does it automatically suggest that effective learning is occurring. SEEL reminds us that learners are individuals, who approach learning both with and without technology in their own distinctive ways. Hearing, understanding and responding to the student voice is fundamental in maximising learning effectiveness. Institutions should consider actively developing the capacity of academic staff to advise students on the usefulness of particular online tools and resources in support of learning and consider the potential benefits of building on what students already use in their everyday lives. Given the widespread perception that students tend to be ‘digital natives’ and academic staff ‘digital immigrants’ (Prensky, 2001), this could represent a considerable cultural challenge

Hubble Space Telescope Fine Guidance Sensor Parallaxes of Galactic Cepheid Variable Stars: Period-Luminosity Relations

(abridged) We present new absolute trigonometric parallaxes and relative proper motions for nine Galactic Cepheid variable stars: l Car, zeta Gem, beta Dor, W Sgr, X Sgr, Y Sgr, FF Aql, T Vul, and RT Aur. We obtain these results with astrometric data from Fine Guidance Sensor 1r, a white-light interferometer on Hubble Space Telescope. We find absolute parallaxes with an average sigma_pi/pi = 8%. Two stars (FF Aql and W Sgr) required the inclusion of binary astrometric perturbations, providing Cepheid mass estimates. With these parallaxes we compute absolute magnitudes in V, I, K, and Wesenheit W_{VI} bandpasses corrected for interstellar extinction and Lutz-Kelker-Hanson bias. Adding our previous absolute magnitude determination for delta Cep, we construct Period-Luminosity relations for ten Galactic Cepheids. We compare our new Period-Luminosity relations with those adopted by several recent investigations, including the Freedman and Sandage H_0 projects. Adopting our Period-Luminosity relationship would tend to increase the Sandage H_$ value, but leave the Freedman H_0 unchanged. Comparing our Galactic Cepheid PLR with those derived from LMC Cepheids, we find the slopes for K and W_{VI} identical in the two galaxies within their respective errors. Our data lead to a W_{VI} distance modulus for the Large Magellanic Cloud, m-M = 18.50\pm0.03, uncorrected for any metallicity effects. Applying recently derived metalllcity corrections yields a corrected LMC distance modulus of (m-M)_0=18.40\pm0.05. Comparing our Period-Luminosity relationship to solar-metallicity Cepheids in NGC 4258 results in a distance modulus, 29.28 \pm 0.08, which agrees with that derived from maser studies.Comment: Accepted paper; to appear in the Astronomical Journa

High pressure evolution of Fe2_{2}O3_{3} electronic structure revealed by X-ray absorption

We report the first high pressure measurement of the Fe K-edge in hematite (Fe$_2$O$_3$) by X-ray absorption spectroscopy in partial fluorescence yield geometry. The pressure-induced evolution of the electronic structure as Fe$_2$O$_3$ transforms from a high-spin insulator to a low-spin metal is reflected in the x-ray absorption pre-edge. The crystal field splitting energy was found to increase monotonically with pressure up to 48 GPa, above which a series of phase transitions occur. Atomic multiplet, cluster diagonalization, and density-functional calculations were performed to simulate the pre-edge absorption spectra, showing good qualitative agreement with the measurements. The mechanism for the pressure-induced phase transitions of Fe$_2$O$_3$ is discussed and it is shown that ligand hybridization significantly reduces the critical high-spin/low-spin pressure.Comment: 5 pages, 4 figures and 1 tabl

Influence of first developer solvent levels on the information storage capacity of negative and reversal images

Silver halide solvents are commonly used in the first developer of a reversal process to obtain brighter highlights and a higher effective speed. An investigation was carried out to determine the effect of a low and high level of solvent on the sensitometric char acteristics as well as the covering power, granularity, modulation transfer function (MTF) and the information storage capacity of Plus-X reversal film 7276. The investigation was designed such that the only variable in the systems studied was the first developer. D-67, i.e., D-19 containing two grams liter^-1 of potassium thiocyanate, was chosen as the high solvent first developer. D-19 with twenty-five grams liter^-1 of sodium sulfite, designated D19-25 in this investigation, was the low solvent first developer. Four systems were studied: 1) negative images developed in a low solvent developer (D19-25) 2) positive images developed in D-19 using a low solvent first developer (D19-25) 3) negative images developed in a high solvent developer (D-6 7) 4) positive images developed in D-19 using a high solvent first developer (D-67) The information storage capacity for each system was calculated from the signal to noise ratio across the spatial frequency range of zero cycles mm^-1 to twenty-five cycles mm^-1. The signal to noise ratio was determined from the gamma value of the D-log H curves, the MTF and the Wiener spectrum ordinate value derived from the granularity. Comparisons between the systems were made for each parameter as well as the information storage capacity. The comparisons were made two different ways: 1) at equal densities and 2) at equal exposures. No significant differences attributable to the solvent were found in the granularity, MTF and the information storage capacity when the ccmparisons were made at density levels of 0.50, 1.00 and 1.50 above base plus fog. Differences were seen in the covering power of each system. Slower speed and dark highlights, as evidenced in the positive D-log H curves, were obtained using D19-25 as the first developer. In creasing the exposure to compensate for the lower speed would not correct the dim highlights. This indicated that perhaps a more viable comparison could be made at equal exposure levels. Differences were observed in the covering power, granularity and information storage capacity when the comparisons were made at equal exposure levels. The covering power did not appear to influence the information storage capacity results since the trends were not the same. The covering power of the D-67 negative system was lower than the D19-25 negative system due to solution-physical development effects. The covering power of the positive systems were not different. The covering power values obtained for the positive systems were about forty- five percent higher than the covering power values. The granularity affected the information storage capacity re sults the most. As the granularity increased across the exposure range the amount of information detected decreased. Larger dif ferences were observed between the positive systems than the negative systems . Positive images developed in D-67 showed cleaner highlights, i.e., a lower D_min. level on the D-log H curve, a higher effective speed, about a ten percent decrease in granularity and an increase of about eighteen percent in the information storage capacity. Processing in a high solvent first developer provided a distinct advantage over development in a low solvent developer in terms of the parameters investigated in this study

Understanding local ethnic inequalities in childhood BMI through cross-sectional analysis of routinely collected local data

Background: Local-level analysis of ethnic inequalities in health is lacking, prohibiting a comprehensive understanding of the health needs of local populations and the design of effective health services. Knowledge of ethnic disparities in child weight status is particularly limited by overlooking both the heterogeneity within ethnic groupings; and the complex ecological contexts in which obesity arises. This study aimed to establish whether there was variation in childhood BMI across ethnic groups in Coventry, and the influence of individual, school and neighbourhood contexts, using routinely collected local data. Methods: National Child Measurement Programme data were compiled for the period 2007/8-2014/15 and combined with routinely collected local data reflecting school performance and demographics, and school and neighbourhood physical environments. Multi-level modelling using Monte Carlo Markov Chain methods was used to account for the clustering of children within schools and neighbourhoods. Ethnic group differences in BMI z-score (zBMI) were explored at 4-5 years and 10-11 years for girls and boys alongside individual, school and neighbourhood covariates. Results: At age 4-5 years (n = 28,407), ethnic group differences were similar for boys and girls, with children from South Asian, White other, Chinese and 'any other' ethnic groups having a significantly lower zBMI, and Black African children having a higher zBMI, versus White British (WB) children. Patterns differed considerably at age 10-11 years (n = 25,763) with marked sex differences. Boys from White other, Bangladeshi and Black African groups had a significantly higher zBMI than WB boys. For girls, only children from Black ethnic groups showed a significantly higher zBMI. Area-level deprivation was the only important school or neighbourhood covariate, but its inclusion did not explain ethnic group differences in child zBMI. Conclusion: This analysis contributes to the existing literature by identifying nuanced patterns of ethnic disparities in childhood adiposity in Coventry, supporting the targeting of early obesity prevention for children from Black African groups, as well as girls from Black Caribbean and Black other ethnic backgrounds; and boys from Bangladeshi and White other ethnic backgrounds. It also demonstrates the utility of exploring routinely collected local data sets in building a comprehensive understanding of local population needs.</p

Specific nuclear envelope transmembrane proteins can promote the location of chromosomes to and from the nuclear periphery

BACKGROUND: Different cell types have distinctive patterns of chromosome positioning in the nucleus. Although ectopic affinity-tethering of specific loci can be used to relocate chromosomes to the nuclear periphery, endogenous nuclear envelope proteins that control such a mechanism in mammalian cells have yet to be widely identified. RESULTS: To search for such proteins twenty three nuclear envelope transmembrane proteins were screened for their ability to promote peripheral localization of human chromosomes in HT1080 fibroblasts. Five of these proteins had strong effects on chromosome 5, but individual proteins affected different subsets of chromosomes. The repositioning effects were reversible and the proteins with effects all exhibited highly tissue-restricted patterns of expression. Depletion of two nuclear envelope transmembrane proteins that were preferentially expressed in liver each reduced the normal peripheral positioning of chromosome 5 in liver cells. CONCLUSIONS: The discovery of nuclear envelope transmembrane proteins that can modulate chromosome position and have restricted patterns of expression may enable dissection of the functional relevance of tissue-specific patterns of radial chromosome positioning.Publisher PDFPeer reviewe

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO