Photometric and proper motion study of neglected open cluster NGC 2215

Optical UBVRI photometric measurements using the Faulkes Telescope North were taken in early 2011 and combined with 2MASS JHK$_s$ and WISE infrared photometry as well as UCAC4 proper motion data in order to estimate the main parameters of the galactic open cluster NGC 2215 of which large uncertainty exists in the current literature. Fitting a King model we estimate a core radius of 1.12$'\pm$0.04$'$ (0.24$\pm$0.01pc) and a limiting radius of $4.3'\pm$0.5$'$ (0.94$\pm$0.11pc) for the cluster. The results of isochrone fits indicates an age of $log(t)=8.85\pm0.10$ with a distance of $d=790\pm90$pc, a metallicity of $[Fe/H]=-0.40\pm0.10$ dex and a reddening of $E(B-V)=0.26\pm0.04$. A proportion of the work in this study was undertaken by Australian and Canadian upper secondary school students involved in the Space to Grow astronomy education project, and is the first scientific publication to have utilized our star cluster photometry curriculum materials.Comment: 10 pages, 9 Figures, 3 Table

Mechanism for nitrogen isotope fractionation during ammonium assimilation by Escherichia coli K12

Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 110 (2013): 8696-8701, doi:10.1073/pnas.1216683110.Organisms that use ammonium as the sole nitrogen source discriminate between [15N] and [14N] ammonium. This selectivity leaves an isotopic signature in their biomass that depends on the external concentration of ammonium. To dissect how differences in discrimination arise molecularly, we examined a wild-type (WT) strain of Escherichia coli K12 and mutant strains with lesions affecting ammonium-assimilatory proteins. We used isotope ratio mass spectrometry (MS) to assess the nitrogen isotopic composition of cell material when the strains were grown in batch culture at either high or low external concentrations of NH3 (achieved by controlling total NH4Cl and pH of the medium). At high NH3 (≥0.89 µM), discrimination against the heavy isotope by the WT strain (−19.2‰) can be accounted for by the equilibrium isotope effect for dissociation of NH4+ to NH3 + H+. NH3 equilibrates across the cytoplasmic membrane, and glutamine synthetase does not manifest an isotope effect in vivo. At low NH3 (≤0.18 µM), discrimination reflects an isotope effect for the NH4+ channel AmtB (−14.1‰). By making E. coli dependent on the low-affinity ammonium-assimilatory pathway, we determined that biosynthetic glutamate dehydrogenase has an inverse isotope effect in vivo (+8.8‰). Likewise, by making unmediated diffusion of NH3 across the cytoplasmic membrane rate-limiting for cell growth in a mutant strain lacking AmtB, we could deduce an in vivo isotope effect for transport of NH3 across the membrane (−10.9‰). The paper presents the raw data from which our conclusions were drawn and discusses the assumptions underlying them.This work was supported by NIH grant GM38361 to S.K. J.M.H. thanks WHOI for support as an emeritus scientist.2013-11-0

Recognition and property in Hegel and the early Marx

The article attempts to show, first, that for Hegel the role of property is to enable persons both to objectify their freedom and to properly express their recognition of each other as free, and second, that the Marx of 1844 uses fundamentally similar ideas in his exposition of communist society. For him the role of ‘true property’ is to enable individuals both to objectify their essential human powers and their individuality, and to express their recognition of each other as fellow human beings with needs, or their ‘human recognition’. Marx further uses these ideas to condemn the society of private property and market exchange as characterised by ‘estranged’ forms of property and recognition. He therefore uses a structure of ideas which Hegel had used to justify the institutions of private property and market exchange in order to condemn those same institutions. It is concluded that Marx’s adoption from Hegel of the idea that property as the means of self-objectification and of expressed recognition, leaves his vision of communism open to the charge that in it, just as in market society, the relations between human beings are mediated by things

Access to diarylmethanols by Wittig rearrangement of ortho-, meta- and para-benzyloxy-N-butylbenzamides

Authors thank EPSRC (UK) for a DTA studentship to ADH (Grant EP/L505079/1), EPSRC (UK) and CRITICAT Centre for Doctoral Training for a studentship to RAI (Grant code: EP/L016419/1) and the EPSRC UK National Mass Spectrometry Facility at Swansea University.The N-butyl amide group, CONHBu, has been found to be an effective promoter of the [1,2]-Wittig rearrangement of aryl benzyl ethers and thus allow the two-step synthesis of isomerically-pure substituted diarylmethanols starting from simple hydroxybenzoic acid derivatives. The method is compatible with a wide range of functional groups including methyl, methoxy and fluoro, although not with nitro and, unexpectedly, is applicable to meta as well as ortho and para isomeric series.Publisher PDFPeer reviewe

A novel route for identifying starch diagenetic products in the archaeological record

This work introduces a novel analytical chemistry method potentially applicable to the study of archaeological starch residues. The investigation involved the laboratory synthesis of model Maillard reaction mixtures and their analysis through Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS). Thus, starch from sixteen plant species were matured while reacting it with the amino acid glycine. The FTICR-MS analysis revealed > 5,300 molecular compounds, with numerous unique heteroatom rich compound classes, ranging from 20 (Zea mays) to 50 (Sorghum bicolor). These classes were investigated as repositories of chemical structure retaining source and process-specific character, linked back to botanical provenance. We discussed the Maillard reaction products thus generated, a possible pathway for the preservation of degraded starch, while also assessing diagenetic recalcitrance and adsorption potential to mineral surfaces. In some cases, hydrothermal experimentation on starches without glycine reveals that the chemical complexity of the starch itself is sufficient to produce some Maillard reaction products. The article concludes that FTICR-MS offers a new analytical window to characterize starchy residue and its diagenetic products, and is able to recognize taxonomic signals with the potential to persist in fossil contexts.Introduction Materials and methods - Sample preparation and characterization - FTICR-MS analysis Results - Characterization of Maillard reaction products based on atomic ratios (H/C, O/C, N/C, N/O) and compound class distribution - Variations in molecular distribution Discussion - The Maillard reaction products - Preservation pathway - Diagenetic recalcitrance of Maillard reaction products Conclusion

Support induced charge transfer effects on electrochemical characteristics of Pt nanoparticle electrocatalysts

The electrokinetic properties of Pt nanoparticles supported on Carbon (Pt/C) and Boron Carbide-Graphite composite (Pt/BC) are compared over a wide potential range. The influence of the support on the electronic state of Pt was investigated via in-situ X-ray Absorption Spectroscopy. Pt d-band filling, determined from XANES white line analysis, was lower and nearly constant between 0.4 and 0.95V vs. RHE for Pt/BC, indicating more positively charged particles in the double layer region and a delay in the onset of oxide formation by about 0.2V compared to the Pt/C catalyst, which showed a marked increase in d-band vacancies above 0.8V vs. RHE. Moreover, δμ analysis of the XANES data indicated a lack of sub-surface oxygen for the Pt/BC catalyst compared to the Pt/C catalyst above 0.9V vs. RHE. Additional anion adsorption on the Pt/BC in the double layer region, detected by CO displacement, was also confirmed by XANES analysis of the d-band occupancy. The H 2 oxidation activities of electrodes with low catalyst loadings were assessed under high mass transport conditions using the floating electrode methodology. The metal-support interaction between the Pt and BC support improved the maximum hydrogen oxidation current density by 1.4 times when compared to Pt/C

Kinds of well-being: A conceptual framework that provides direction for caring

This article offers a conceptual framework by which different kinds and levels of well-being can be named, and as such, provides a foundation for a resource-oriented approach in situations of illness and vulnerability (rather than a deficit-oriented approach). Building on a previous paper that articulated the philosophical foundations of an existential theory of well-being (“Dwelling-mobility”), we show here how the theory can be further developed towards practice-relevant concerns. We introduce 18 kinds of well-being that are intertwined and inter-related, and consider how each emphasis can lead to the formulation of resources that have the potential to give rise to well-being as a felt experience. By focusing on a much wider range of well-being possibilities, practitioners may find new directions for care that are not just literal but also at an existential level

Slow violence and toxic geographies : ‘out of sight’ to whom?

Toxic pollution is a form of violence. This article explores the gradual brutalities that communities surrounded by petrochemical infrastructure endure over time. Contributing to political geographies of violence and environmental justice, this paper puts the concept of ‘slow violence’ into critical comparison with work on ‘structural violence’. In doing so, the paper makes two key contributions: First, it emphasizes the intimate connections between structural and slow forms of harm, arguing that structural inequality can mutate into noxious instances of slow violence. Second, the paper pushes back against framings of toxic landscapes as entirely invisible to the people they impact. Instead of accepting the standard definition of slow violence as ‘out of sight’, we have to instead ask the question: ‘out of sight to whom?’ In asking this question, and taking seriously the knowledge claims of communities who inhabit toxic spaces, we can begin to unravel the political structures that sustain the uneven geographies of pollution. Based on long-term ethnographic research in a postcolonial region of Louisiana, nicknamed ‘Cancer Alley’, this paper reveals how people gradually ‘witness’ the impacts of slow violence in their everyday lives. Finally, drawing on the notion of ‘epistemic violence’, the paper suggests that slow violence does not persist due to a lack of arresting stories about pollution, but because these stories do not count, thus rendering certain populations and geographies vulnerable to sacrifice

From Aristotle to Arendt : a phenomenological exploration of forms of knowledge and practice in the context of child protection social work in the UK

This paper attempts to explore the relationship between different forms of knowledge and the kinds of activity that arise from them within child protection social work practice. The argument that social work is more than either ‘science’ or ‘art’ but distinctly ‘practice’ is put through a historical description of the development of Aristotle’s views of the forms of knowledge and Hannah Arendt’s later conceptualisations as detailed in The Human Condition (1958). The paper supports Arendt’s privileging of Praxis over Theoria within social work and further draws upon Arendt’s distinctions between Labour, Work and Action to delineate between different forms of social work activity. The author highlights dangers in social work relying too heavily on technical knowledge and the use of theory as a tool in seeking to understand and engage with the people it serves and stresses the importance of a phenomenological approach to research and practice as a valid, embodied form of knowledge. The argument further explores the constructions of service users that potentially arise from different forms of social work activity and cautions against over-prescriptive use of ‘outcomes’ based practice that may reduce the people who use services to products or consumables. The author concludes that social work action inevitably involves trying to understand humans in a complex and dynamic way that requires engagement and to seek new meanings for individual humans

Using Genomic Sequencing for Classical Genetics in E. coli K12

We here develop computational methods to facilitate use of 454 whole genome shotgun sequencing to identify mutations in Escherichia coli K12. We had Roche sequence eight related strains derived as spontaneous mutants in a background without a whole genome sequence. They provided difference tables based on assembling each genome to reference strain E. coli MG1655 (NC_000913). Due to the evolutionary distance to MG1655, these contained a large number of both false negatives and positives. By manual analysis of the dataset, we detected all the known mutations (24 at nine locations) and identified and genetically confirmed new mutations necessary and sufficient for the phenotypes we had selected in four strains. We then had Roche assemble contigs de novo, which we further assembled to full-length pseudomolecules based on synteny with MG1655. This hybrid method facilitated detection of insertion mutations and allowed annotation from MG1655. After removing one genome with less than the optimal 20- to 30-fold sequence coverage, we identified 544 putative polymorphisms that included all of the known and selected mutations apart from insertions. Finally, we detected seven new mutations in a total of only 41 candidates by comparing single genomes to composite data for the remaining six and using a ranking system to penalize homopolymer sequencing and misassembly errors. An additional benefit of the analysis is a table of differences between MG1655 and a physiologically robust E. coli wild-type strain NCM3722. Both projects were greatly facilitated by use of comparative genomics tools in the CoGe software package (http://genomevolution.org/)