Relating pore fabric geometry to acoustic and permeability anisotropy in Crab Orchard Sandstone: A laboratory study using magnetic ferrofluid

Pore fabric anisotropy is a common feature of many sedimentary rocks. In this paper we report results from a comparative study on the anisotropy of a porous sandstone (Crab Orchard) using anisotropy of magnetic susceptibility (AMS), acoustic wave velocity and fluid permeability techniques. Initially, we characterise the anisotropic pore fabric geometry by impregnating the sandstone with magnetic ferro-fluid and measuring its AMS. The results are used to guide subsequent measurements of the anisotropy of acoustic wave velocity and fluid permeability. These three independent measures of anisotropy are then directly compared. Results show strong positive correlation between the principal directions given from the AMS, velocity anisotropy and permeability anisotropy. Permeability parallel to the macroscopic crossbedding observed in the sandstone is 240% higher than that normal to it. P and S-wave velocity anisotropy and AMS show mean values of 19.1%, 4.8% and 3.8% respectively, reflecting the disparate physical properties measured

Recent advances in the application of stable isotope ratio analysis in forensic chemistry

This review paper updates the previous literature in relation to the continued and developing use of stable isotope ratio analysis in samples which are relevant to forensic science. Recent advances in the analysis of drug samples, explosive materials, and samples derived from human and animal samples are discussed. The paper also aims to put the use of isotope ratio mass spectrometry into a forensic context and discuss its evidential potential

Comparing international coverage of 9/11 : towards an interdisciplinary explanation of the construction of news

This article presents an interdisciplinary model attempting to explain how news is constructed by relying on the contributions of different fields of study: News Sociology, Political Communications, International Communications, International Relations. It is a first step towards developing a holistic theoretical approach to what shapes the news, which bridges current micro to macro approaches. More precisely the model explains news variation across different media organization and countries by focusing on the different way the sense of newsworthiness of journalists is affected by three main variables: national interest, national journalistic culture, and editorial policy of each media organization. The model is developed on the basis of an investigation into what shaped the media coverage of 9/11 in eight elite newspapers across the US, France, Italy and Pakistan

Climate-mediated diversification of turtles in the Cretaceous

The file attached is the published version of the article

Tearing Out the Income Tax by the (Grass)Roots

Landscapes are increasingly fragmented, and conservation programs have started to look at network approaches for maintaining populations at a larger scale. We present an agent-based model of predator–prey dynamics where the agents (i.e. the individuals of either the predator or prey population) are able to move between different patches in a landscaped network. We then analyze population level and coexistence probability given node-centrality measures that characterize specific patches. We show that both predator and prey species benefit from living in globally well-connected patches (i.e. with high closeness centrality). However, the maximum number of prey species is reached, on average, at lower closeness centrality levels than for predator species. Hence, prey species benefit from constraints imposed on species movement in fragmented landscapes since they can reproduce with a lesser risk of predation, and their need for using anti-predatory strategies decreases.authorCount :

The detection of the imprint of filaments on cosmic microwave background lensing

Galaxy redshift surveys, such as 2dF, SDSS, 6df, GAMA and VIPERS, have shown that the spatial distribution of matter forms a rich web, known as the cosmic web. The majority of galaxy survey analyses measure the amplitude of galaxy clustering as a function of scale, ignoring information beyond a small number of summary statistics. Since the matter density field becomes highly non-Gaussian as structure evolves under gravity, we expect other statistical descriptions of the field to provide us with additional information. One way to study the non-Gaussianity is to study filaments, which evolve non-linearly from the initial density fluctuations produced in the primordial Universe. In our study, we report the first detection of CMB (Cosmic Microwave Background) lensing by filaments and we apply a null test to confirm our detection. Furthermore, we propose a phenomenological model to interpret the detected signal and we measure how filaments trace the matter distribution on large scales through filament bias, which we measure to be around 1.5. Our study provides a new scope to understand the environmental dependence of galaxy formation. In the future, the joint analysis of lensing and Sunyaev-Zel'dovich observations might reveal the properties of `missing baryons', the vast majority of the gas which resides in the intergalactic medium and has so far evaded most observations

Prevalence and dynamics of ribosomal DNA micro-heterogeneity are linked to population history in two contrasting yeast species

Despite the considerable number and taxonomic breadth of past and current genome sequencing projects, many of which necessarily encompass the ribosomal DNA, detailed information on the prevalence and evolutionary significance of sequence variation in this ubiquitous genomic region are severely lacking. Here, we attempt to address this issue in two closely related yet contrasting yeast species, the baker's yeast Saccharomyces cerevisiae and the wild yeast Saccharomyces paradoxus. By drawing on existing datasets from the Saccharomyces Genome Resequencing Project, we identify a rich seam of ribosomal DNA sequence variation, characterising 1,068 and 970 polymorphisms in 34 S. cerevisiae and 26 S. paradoxus strains respectively. We discover the two species sets exhibit distinct mutational profiles. Furthermore, we show for the first time that unresolved rDNA sequence variation resulting from imperfect concerted evolution of the ribosomal DNA region follows a U-shaped allele frequency distribution in each species, similar to loci that evolve under non-concerted mechanisms but arising through rather different evolutionary processes. Finally, we link differences between the shapes of these allele frequency distributions to the two species' contrasting population histories

Multiple ITS Copies Reveal Extensive Hybridization within Rheum (Polygonaceae), a Genus That Has Undergone Rapid Radiation

During adaptive radiation events, characters can arise multiple times due to parallel evolution, but transfer of traits through hybridization provides an alternative explanation for the same character appearing in apparently non-sister lineages. The signature of hybridization can be detected in incongruence between phylogenies derived from different markers, or from the presence of two divergent versions of a nuclear marker such as ITS within one individual.In this study, we cloned and sequenced ITS regions for 30 species of the genus Rheum, and compared them with a cpDNA phylogeny. Seven species contained two divergent copies of ITS that resolved in different clades from one another in each case, indicating hybridization events too recent for concerted evolution to have homogenised the ITS sequences. Hybridization was also indicated in at least two further species via incongruence in their position between ITS and cpDNA phylogenies. None of the ITS sequences present in these nine species matched those detected in any other species, which provides tentative evidence against recent introgression as an explanation. Rheum globulosum, previously indicated by cpDNA to represent an independent origin of decumbent habit, is indicated by ITS to be part of clade of decumbent species, which acquired cpDNA of another clade via hybridization. However decumbent and glasshouse morphology are confirmed to have arisen three and two times, respectively.These findings suggested that hybridization among QTP species of Rheum has been extensive, and that a role of hybridization in diversification of Rheum requires investigation

Therapeutic issues in HIV/HCV-coinfected patients

The importance of treating hepatitis C virus (HCV)-associated morbidities in a growing population of patients coinfected with human immunodeficiency virus (HIV) has increased since the introduction of highly active antiretroviral therapy. As a result, investigative attention is turning to HCV-related liver disease and treatment-associated issues in coinfection. HIV/HCV-coinfected patients have higher HCV RNA loads and show more rapid progression of fibrosis than do monoinfected patients. Combination therapy with pegylated interferon plus ribavirin (RBV) is the standard of care for HCV in coinfected patients. Therapy slows fibrosis progression, but toxicity prevents identification of the most effective RBV dose. Coinfected patients have about a threefold greater risk of antiretroviral therapy-associated hepatotoxicity than patients with HIV only. Other challenges include anaemia, mitochondrial toxicity, drug–drug interactions and leucopenia. Thus, chronic hepatitis C should be treated in HIV/HCV-coinfected patients, but steps must be taken to prevent and treat potential toxicities. The first European Consensus Conference on the Treatment of Chronic Hepatitis B and C in HIV Co-infected Patients was held March 2005 in Paris to address these issues. This article reviews the peer-reviewed literature and expert opinion published from 1990 to 2005, and compares results with presentations and recommendations from the Consensus Conference to best present current issues in coinfection