Constraints on the pMSSM from LAT Observations of Dwarf Spheroidal Galaxies

We examine the ability for the Large Area Telescope (LAT) to constrain Minimal Supersymmetric Standard Model (MSSM) dark matter through a combined analysis of Milky Way dwarf spheroidal galaxies. We examine the Lightest Supersymmetric Particles (LSPs) for a set of ~71k experimentally valid supersymmetric models derived from the phenomenological-MSSM (pMSSM). We find that none of these models can be excluded at 95% confidence by the current analysis; nevertheless, many lie within the predicted reach of future LAT analyses. With two years of data, we find that the LAT is currently most sensitive to light LSPs (m_LSP < 50 GeV) annihilating into tau-pairs and heavier LSPs annihilating into b-bbar. Additionally, we find that future LAT analyses will be able to probe some LSPs that form a sub-dominant component of dark matter. We directly compare the LAT results to direct detection experiments and show the complementarity of these search methods.Comment: 24 pages, 9 figures, submitted to JCA

Dark Energy from structure: a status report

The effective evolution of an inhomogeneous universe model in any theory of gravitation may be described in terms of spatially averaged variables. In Einstein's theory, restricting attention to scalar variables, this evolution can be modeled by solutions of a set of Friedmann equations for an effective volume scale factor, with matter and backreaction source terms. The latter can be represented by an effective scalar field (`morphon field') modeling Dark Energy. The present work provides an overview over the Dark Energy debate in connection with the impact of inhomogeneities, and formulates strategies for a comprehensive quantitative evaluation of backreaction effects both in theoretical and observational cosmology. We recall the basic steps of a description of backreaction effects in relativistic cosmology that lead to refurnishing the standard cosmological equations, but also lay down a number of challenges and unresolved issues in connection with their observational interpretation. The present status of this subject is intermediate: we have a good qualitative understanding of backreaction effects pointing to a global instability of the standard model of cosmology; exact solutions and perturbative results modeling this instability lie in the right sector to explain Dark Energy from inhomogeneities. It is fair to say that, even if backreaction effects turn out to be less important than anticipated by some researchers, the concordance high-precision cosmology, the architecture of current N-body simulations, as well as standard perturbative approaches may all fall short in correctly describing the Late Universe.Comment: Invited Review for a special Gen. Rel. Grav. issue on Dark Energy, 59 pages, 2 figures; matches published versio

Gene and repetitive sequence annotation in the Triticeae

The Triticeae tribe contains some of the world’s most important agricultural crops (wheat, barley and rye) and is perhaps, one of the most challenging for genome annotation because Triticeae genomes are primarily composed of repetitive sequences. Further complicating the challenge is the polyploidy found in wheat and particularly in the hexaploid bread wheat genome. Genomic sequence data are available for the Triticeae in the form of large collections of Expressed Sequence Tags (>1.5 million) and an increasing number of bacterial artificial chromosome clone sequences. Given that high repetitive sequence content in the Triticeae confounds annotation of protein-coding genes, repetitive sequences have been identified, annotated, and collated into public databases. Protein coding genes in the Triticeae are structurally annotated using a combination of ab initio gene finders and experimental evidence. Functional annotation of protein coding genes involves assessment of sequence similarity to known proteins, expression evidence, and the presence of domain and motifs. Annotation methods and tools for Triticeae genomic sequences have been adapted from existing plant genome annotation projects and were designed to allow for flexibility of single sequence annotation while allowing a whole community annotation effort to be developed. With the availability of an increasing number of annotated grass genomes, comparative genomics can be exploited to accelerate and enhance the quality of Triticeae sequences annotation. This chapter provides a brief overview of the Triticeae genomes features that are challenging for genome annotation and describes the resources and methods available for sequence annotation with a particular emphasis on problems caused by the repetitive fraction of these genomes

The Role of Local Intermediaries in the Process of Digitally Engaging Non-Users of the Internet

This article aims to provide a better understanding of the process of becoming digitally engaged. Those who cannot utilise digital networks are systematically disadvantaged, particularly in a hyper-connected world in which services are provided online by default. By interviewing and observing clients and trainers at a telecentre, the ACT Digital Hub, this study investigated the process that non-internet users undergo-from digital readiness to digital engagement-in order to become adept users. Intermediaries such as telecentres play a crucial role in equipping non-users with digital readiness, which is a precursor to digital media literacy. Social environment also plays a significant role in non-users' digital readiness. Rather than focusing merely on the provision of access to bridge the digital divide, we need a longer-term investment in adequate environments, such as sustainable community training centres, that nurture digital readiness.</p