Large Magellanic Cloud Planetary Nebula Morphology: Probing Stellar Populations and Evolution

Planetary Nebulae (PNe) in the Large Magellanic Cloud (LMC) offer the unique opportunity to study both the Population and evolution of low- and intermediate-mass stars, by means of the morphological type of the nebula. Using observations from our LMC PN morphological survey, and including images available in the HST Data Archive, and published chemical abundances, we find that asymmetry in PNe is strongly correlated with a younger stellar Population, as indicated by the abundance of elements that are unaltered by stellar evolution (Ne, Ar, S). While similar results have been obtained for Galactic PNe, this is the first demonstration of the relationship for extra-galactic PNe. We also examine the relation between morphology and abundance of the products of stellar evolution. We found that asymmetric PNe have higher nitrogen and lower carbon abundances than symmetric PNe. Our two main results are broadly consistent with the predictions of stellar evolution if the progenitors of asymmetric PNe have on average larger masses than the progenitors of symmetric PNe. The results bear on the question of formation mechanisms for asymmetric PNe, specifically, that the genesis of PNe structure should relate strongly to the Population type, and by inference the mass, of the progenitor star, and less strongly on whether the central star is a member of a close binary system.Comment: The Astrophysical Journal Letters, in press 4 figure

Genome-to-genome analysis highlights the effect of the human innate and adaptive immune systems on the hepatitis C virus

Outcomes of hepatitis C virus (HCV) infection and treatment depend on viral and host genetic factors. Here we use human genome-wide genotyping arrays and new whole-genome HCV viral sequencing technologies to perform a systematic genome-to-genome study of 542 individuals who were chronically infected with HCV, predominantly genotype 3. We show that both alleles of genes encoding human leukocyte antigen molecules and genes encoding components of the interferon lambda innate immune system drive viral polymorphism. Additionally, we show that IFNL4 genotypes determine HCV viral load through a mechanism dependent on a specific amino acid residue in the HCV NS5A protein. These findings highlight the interplay between the innate immune system and the viral genome in HCV control

Detailed Decomposition of Galaxy Images. II. Beyond Axisymmetric Models

We present a two-dimensional (2-D) fitting algorithm (GALFIT, Version 3) with new capabilities to study the structural components of galaxies and other astronomical objects in digital images. Our technique improves on previous 2-D fitting algorithms by allowing for irregular, curved, logarithmic and power-law spirals, ring and truncated shapes in otherwise traditional parametric functions like the Sersic, Moffat, King, Ferrer, etc., profiles. One can mix and match these new shape features freely, with or without constraints, apply them to an arbitrary number of model components and of numerous profile types, so as to produce realistic-looking galaxy model images. Yet, despite the potential for extreme complexity, the meaning of the key parameters like the Sersic index, effective radius or luminosity remain intuitive and essentially unchanged. The new features have an interesting potential for use to quantify the degree of asymmetry of galaxies, to quantify low surface brightness tidal features beneath and beyond luminous galaxies, to allow more realistic decompositions of galaxy subcomponents in the presence of strong rings and spiral arms, and to enable ways to gauge the uncertainties when decomposing galaxy subcomponents. We illustrate these new features by way of several case studies that display various levels of complexity.Comment: 41 pages, 22 figures, AJ accepted. Minor changes. Full resolution version of this paper is available at: http://users.obs.carnegiescience.edu/peng/work/galfit/galfit3.pd

Association between canine leishmaniosis and Ehrlichia canis co-infection: a prospective case-control study

Abstract Background In the Mediterranean basin, Leishmania infantum is a major cause of disease in dogs, which are frequently co-infected with other vector-borne pathogens (VBP). However, the associations between dogs with clinical leishmaniosis (ClinL) and VBP co-infections have not been studied. We assessed the risk of VBP infections in dogs with ClinL and healthy controls. Methods We conducted a prospective case-control study of dogs with ClinL (positive qPCR and ELISA antibody for L. infantum on peripheral blood) and clinically healthy, ideally breed-, sex- and age-matched, control dogs (negative qPCR and ELISA antibody for L. infantum on peripheral blood) from Paphos, Cyprus. We obtained demographic data and all dogs underwent PCR on EDTA-blood extracted DNA for haemoplasma species, Ehrlichia/Anaplasma spp., Babesia spp., and Hepatozoon spp., with DNA sequencing to identify infecting species. We used logistic regression analysis and structural equation modelling (SEM) to evaluate the risk of VBP infections between ClinL cases and controls. Results From the 50 enrolled dogs with ClinL, DNA was detected in 24 (48%) for Hepatozoon spp., 14 (28%) for Mycoplasma haemocanis, 6 (12%) for Ehrlichia canis and 2 (4%) for Anaplasma platys. In the 92 enrolled control dogs, DNA was detected in 41 (45%) for Hepatozoon spp., 18 (20%) for M. haemocanis, 1 (1%) for E. canis and 3 (3%) for A. platys. No Babesia spp. or “Candidatus Mycoplasma haematoparvum” DNA was detected in any dog. No statistical differences were found between the ClinL and controls regarding age, sex, breed, lifestyle and use of ectoparasitic prevention. A significant association between ClinL and E. canis infection (OR = 12.4, 95% CI: 1.5–106.0, P = 0.022) was found compared to controls by multivariate logistic regression. This association was confirmed using SEM, which further identified that younger dogs were more likely to be infected with each of Hepatozoon spp. and M. haemocanis, and dogs with Hepatozoon spp. were more likely to be co-infected with M. haemocanis. Conclusions Dogs with ClinL are at a higher risk of co-infection with E. canis than clinically healthy dogs. We recommend that dogs diagnosed with ClinL should be tested for E. canis co-infection using PCR

Growing Greener: Creating a New Values-based Environmental Engagement Toolkit for SME Intermediaries

This paper explores a radically different way of facilitating energy and environmental initiatives in small and medium-sized enterprises (SMEs). In terms of energy policy, smaller firms in Europe are exempted from most of the major fiscal and regulatory mechanisms that are applied to larger organisations. Policies to reduce energy demand and associated carbon emissions in SMEs are largely based on providing incentives, such as face-to-face support and grants for energy efficiency in buildings. Energy advisors are therefore key intermediaries, providing advice and encouraging the uptake of low carbon technologies and practices by SMEs. Previous studies have found that advisors often find it difficult to engage effectively with SME owners and managers, and that traditional ‘win-win’ messaging can have limited impact, resulting in implementation problems such as under-investment in energy-saving technologies, reluctance to adopt new environmental practices, and a tendency to revert to previous ways of operating once the incentive is removed. Recent research also suggests that SME owners’ and managers’ personal values play an important mediating role in their response to environmental issues, acting in combination with more established factors such as educational background, access to resources and the views of customers and suppliers. The implication is that policy interventions in this area could be delivered in more cost-effective ways if accompanied by a more nuanced, values-based approach to engagement. This paper reports findings from ‘Growing Greener’ a UK multi-disciplinary project that aims to equip advisors and other types of intermediary with the skills, knowledge and understanding they need in order to incorporate a values-based approach into their existing interactions with SMEs. It opens with an overview of the policy context and a brief overview of the relevant research literature. The main section explains how the research team co-produced a values-based engagement toolkit in conjunction with a group of energy advisors and external specialists. The design process included a series of facilitated ‘narrative workshops’, where advisors shared their experiences and experimented with early versions of the engagement tools. This is followed by an outline of the completed engagement ‘toolkit’, which includes free-to-access online course, a communication guide and an interactive engagement tool. These three inter-related components are designed to help advisors to engage SMEs beyond a narrow, cost-benefit framework, and in turn help SME owners and managers to connect low carbon choices with the personal and business values that are important to them as individuals. Our findings indicate the potential for more effective, longer-lasting interventions beyond the low hanging fruit of building efficiency measures

Detailed Structural Decomposition of Galaxy Images

We present a two-dimensional (2-D) fitting algorithm (GALFIT) designed to extract structural components from galaxy images, with emphasis on closely modeling light profiles of spatially well-resolved, nearby galaxies observed with the Hubble Space Telescope. Our algorithm improves on previous techniques in two areas, by being able to simultaneously fit a galaxy with an arbitrary number of components, and with optimization in computation speed, suited for working on large galaxy images. We use 2-D models such as the ``Nuker'' law, the Sersic (de Vaucouleurs) profile, an exponential disk, and Gaussian or Moffat functions. The azimuthal shapes are generalized ellipses that can fit disky and boxy components. Many galaxies with complex isophotes, ellipticity changes, and position-angle twists can be modeled accurately in 2-D. When examined in detail, we find that even simple-looking galaxies generally require at least three components to be modeled accurately, rather than the one or two components more often employed. We illustrate this by way of 7 case studies, which include regular and barred spiral galaxies, highly disky lenticular galaxies, and elliptical galaxies displaying various levels of complexities. A useful extension of this algorithm is to accurately extract nuclear point sources in galaxies. We compare 2-D and 1-D extraction techniques on simulated images of galaxies having nuclear slopes with different degrees of cuspiness, and we then illustrate the application of the program to several examples of nearby galaxies with weak nuclei.Comment: 29 pages, 14 figures, abridged version. Full version AJ accepted. For full version with high resolution figures, go to: http://zwicky.as.arizona.edu/~cyp/work/galfit.ps.g

Glycaemic Index, Glycaemic Load and dietary fibre characteristics of two commercially available fruit smoothies

In light of the updated Eatwell Guide and the corresponding change in the consumption of fruit smoothies, the aim of this study was to measure the glycaemic index and load of two commercial fruit smoothies and to investigate the retention of dietary fibre following production. In vitro analysis was performed to identify fibre material (cellulose and pectins) using calcofluor staining and immunocytochemical labelling. A repeated measures crossover study was conducted (n 10) to determine the Glycaemic Index (GI) and Glycaemic Load (GL) of the smoothies. Results showed that dietary fibre was still present in the smoothies after processing (16.9-17.5% cellular material by dry weight). The GI was low for both smoothies (39 and 36), whereas the GL was medium and borderline-low, respectively (11.4 and 9.7). The retention of fibre in these smoothies may have a potential positive effect on glycaemic response and may contribute to daily fibre requirements

Biomarker discovery and redundancy reduction towards classification using a multi-factorial MALDI-TOF MS T2DM mouse model dataset

Diabetes like many diseases and biological processes is not mono-causal. On the one hand multifactorial studies with complex experimental design are required for its comprehensive analysis. On the other hand, the data from these studies often include a substantial amount of redundancy such as proteins that are typically represented by a multitude of peptides. Coping simultaneously with both complexities (experimental and technological) makes data analysis a challenge for Bioinformatics