Star-forming galaxies in low-redshift clusters: Data and integrated galaxy properties

This paper is a continuation of an ongoing study of the evolutionary processes affecting cluster galaxies. Both CCD R band and H alpha narrow-band imaging was used to determine photometric parameters (m_(r), r_(24), H alpha flux and equivalent width) and derive star formation rates for 227 CGCG galaxies in 8 low-redshift clusters. The galaxy sample is a subset of CGCG galaxies in an objective prism survey of cluster galaxies for H alpha emission. It is found that detection of emission-line galaxies in the OPS is 85%, 70%, and 50% complete at the mean surface brightness values of 1.25 x 10^(-19), 5.19 x 10^(-20), and 1.76 x 10^(-20) W m^(-2) arcsec^(-2), respectively, measured within the R band isophote of 24 mag arcsec^(-2) for the galaxy. The CCD data, together with matched data from a recent H alpha galaxy survey of UGC galaxies within 3000 km s^(-1), will be used for a comparative study of R band and H alpha surface photometry between cluster and field spirals.Comment: Accepted for publication in A&A. 11 pages, including 6 figure

Investigation of the siliceous hydrogel phase formation in glass-ionomer cement paste

The microstructure evolution of a complex glass-ionomer cement (GIC) paste over the first 72 h of the cement setting reaction was investigated by small-angle neutron scattering (SANS) and infrared spectroscopy. GIC is a biocompatible material which is clinically used for dental fillings. In this study, GIC pastes were prepared, following the ISO9917-1:2007 cement preparation method, from medical grade poly(acrylic acid), SiO₂–Al₂O₃–P₂O₅–CaO–CaF₂ -based fluoroaluminosilicate glass and H₂O/D₂O solvent. During the setting reaction, polyacrylic acid attacks the fluoroaluminosilicate glass particles to form a siliceous hydrogel phase, glass core and hydrated polyacrylate matrix. The formation of the siliceous hydrogel structure and cross-linking of polyacrylate chains play important roles to harden the GIC. Infrared spectroscopy was used to identify the formation of the hydrogel phase and cross-linkage in GIC paste. In addition this paper reports SANS measurements for GIC pastes at different contrast conditions (H₂O:D₂O ratio) from the Bilby instrument at the Australian Centre for Neutron Scattering, ANSTO, Australia. The SANS data provide microstructure information for the hydrogel phase in GIC paste over the length scale of 10–5000 Å

Re-structuring of marine communities exposed to environmental change

Species richness is the most commonly used but controversial biodiversity metric in studies on aspects of community stability such as structural composition or productivity. The apparent ambiguity of theoretical and experimental findings may in part be due to experimental shortcomings and/or heterogeneity of scales and methods in earlier studies. This has led to an urgent call for improved and more realistic experiments. In a series of experiments replicated at a global scale we translocated several hundred marine hard bottom communities to new environments simulating a rapid but moderate environmental change. Subsequently, we measured their rate of compositional change (re-structuring) which in the great majority of cases represented a compositional convergence towards local communities. Re-structuring is driven by mortality of community components (original species) and establishment of new species in the changed environmental context. The rate of this re-structuring was then related to various system properties. We show that availability of free substratum relates negatively while taxon richness relates positively to structural persistence (i.e., no or slow re-structuring). Thus, when faced with environmental change, taxon-rich communities retain their original composition longer than taxon-poor communities. The effect of taxon richness, however, interacts with another aspect of diversity, functional richness. Indeed, taxon richness relates positively to persistence in functionally depauperate communities, but not in functionally diverse communities. The interaction between taxonomic and functional diversity with regard to the behaviour of communities exposed to environmental stress may help understand some of the seemingly contrasting findings of past research

Star-forming galaxies in low-redshift clusters: Comparison of integrated properties of cluster and field galaxies

We investigate the effect of the cluster environment on the star formation properties of galaxies in 8 nearby Abell clusters. Star formation properties are determined for individual galaxies using the equivalent width of H alpha plus [NII] line emission from narrow-band imaging. Equivalent width distributions are derived for each galaxy type in each of 3 environments - cluster, supercluster (outside the cluster virial radius) and field. The effects of morphological disturbance on star formation are also investigated. We identify a population of early-type disk galaxies in the cluster population with enhanced star formation compared to their field counterparts. The enhanced cluster galaxies frequently show evidence of disturbance, and the disturbed galaxies show marginal evidence for a higher velocity dispersion, possibly indicative of an infalling population.Comment: 9 pages, 10 figures, accepted for publication in Astronomy and Astrophysic

Heterogeneity of human Neutrophil CD177 expression results from CD177P1 Pseudogene Conversion

Most humans harbor both CD177neg and CD177pos neutrophils but 1–10% of people are CD177null, placing them at risk for formation of anti-neutrophil antibodies that can cause transfusion-related acute lung injury and neonatal alloimmune neutropenia. By deep sequencing the CD177 locus, we catalogued CD177 single nucleotide variants and identified a novel stop codon in CD177null individuals arising from a single base substitution in exon 7. This is not a mutation in CD177 itself, rather the CD177null phenotype arises when exon 7 of CD177 is supplied entirely by the CD177 pseudogene (CD177P1), which appears to have resulted from allelic gene conversion. In CD177 expressing individuals the CD177 locus contains both CD177P1 and CD177 sequences. The proportion of CD177hi neutrophils in the blood is a heritable trait. Abundance of CD177hi neutrophils correlates with homozygosity for CD177 reference allele, while heterozygosity for ectopic CD177P1 gene conversion correlates with increased CD177neg neutrophils, in which both CD177P1 partially incorporated allele and paired intact CD177 allele are transcribed. Human neutrophil heterogeneity for CD177 expression arises by ectopic allelic conversion. Resolution of the genetic basis of CD177null phenotype identifies a method for screening for individuals at risk of CD177 isoimmunisation

WebCSD: the online portal to the Cambridge Structural Database

The new web-based application WebCSD is introduced, which provides a range of facilities for searching the Cambridge Structural Database within a standard web browser. Search options within WebCSD include two-dimensional substructure, molecular similarity, text/numeric and reduced cell searching

A cereal problem? What the current chronology of early cereal domesticates might tell us about changes in late fifth and early fourth millennium cal BC Ireland and Britain

In the years since the last volume on plant domesticates in Ireland and Britain in the fourth millennium[AQ1] cal BC (Fairburn, A., ed. [2000]. Plants in Neolithic Britain and Beyond. Oxford: Oxbow)[AQ2], a number of significant changes have occurred in archaeological practice. These have included the routine application of a range of archaeological science techniques, including Bayesian statistical modelling. During the same period, large-scale sampling strategies in developer-led professional practice, and especially on large infrastructure projects, have increased the available materials for study. This paper will present a new analysis of radiocarbon results from direct measurements on domesticated plant remains from Ireland and Britain to explore what these can tell us about the nature of the changes in the archaeological record at this time. Cereals may appear after the introduction of practices including monuments in the form of causewayed enclosures, tombs and post-and-slot-built structures, in several regions. This approach is new because it unpacks the ‘Neolithic package’, by comparing direct estimates on plant domesticates with the appearance of other forms of material culture and new site types. ‘Unpacking the package’ here (or in other periods critically engaging with culture historic-derived analytical constructs) is important in three ways, which will be discussed in this paper. As well as allowing us to examine the fine-grained nature of changes, developments in chronological modelling should cause us to re-examine how useful our existing terms of engagement are; we need to think not only about the changes we can produce in the sequence of archaeological knowledge, but also in the structure of it

Inventing the Neolithic? Putting evidence-based interpretation back into the study of faunal remains from causewayed enclosures.

ArticleThis is an Accepted Manuscript of an article published by Taylor & Francis in World Archaeology on 2015, available online: http://wwww.tandfonline.com/10.1080/00438243.2015.1072476The paper argues that our current understanding of the animal bones from causewayed enclosure sites in Britain is flawed. During the 1980-90s, a number of key interpretations, still frequently espoused, were based more upon anecdote and theory-driven assertion than on empirical evidence. An example is that evidence of bone processing (butchery and bone fracture) does not feature heavily in the faunal record from causewayed enclosures. Using data from the sites of Etton and Staines, this view must now be questioned. Both butchery and peri-mortem bone fracture are present in these assemblages in substantial quantities. These sites are compared with Ludwinowo 7, a Linearbandkeramik settlement site in Poland and there are considerable similarities between the three different sites. This suggests possibility that the broader economic utility of animal bone assemblages at causewayed enclosures has been underestimated, having been, up to now, regarded as ‘not indicative of domestic settlement’

Surgical impact on brain tumor invasion: A physical perspective

It is conventional strategy to treat highly malignant brain tumors initially with cytoreductive surgery followed by adjuvant radio- and chemotherapy. However, in spite of all such efforts, the patients' prognosis remains dismal since residual glioma cells continue to infiltrate adjacent parenchyma and the tumors almost always recur. On the basis of a simple biomechanical conjecture that we have introduced previously, we argue here that by affecting the 'volume-pressure' relationship and minimizing surface tension of the remaining tumor cells, gross total resection may have an inductive effect on the invasiveness of the tumor cells left behind. Potential implications for treatment strategies are discussed