A catalogue of absorption-line systems in QSO spectra

We present a new catalog of absprption-line systems identified in the quasar spectra. It contains data on 821 QSOs and 8558 absorption systems comprizing 16139 absorption lines with measured redshifts in the QSO spectra. The catalog includes absorption-line systems consisting of lines of heavy elements, lines of neutral hydrogen, Lyman limit systems, damped Ly\alpha absorption systems, and broad absorption-line systems. The catalog is available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/412/707 and at www.ioffe.ru/astro/QC. Using the data of the present catalog we also discuss redshift distributions of absorption-line systems.Comment: 3 pages with 1 postscript figur

BMP signals: Mediated by stroma or thymocytes?

This is an invited comment on the paper by Hager-Theodorides AL, et al. Cell Cycle 2014; 13:324–33; PMID:24240189; http://dx.doi.org/10.4161/cc.27118 which is published in the same journa

Can the quality of social research on ethnicity be improved through the introduction of guidance? Findings from a research commissioning pilot exercise

As the volume of UK social research addressing ethnicity grows, so too do concerns regarding the ethical and scientific rigour of this research domain and its potential to do more harm than good. The establishment of standards and principles and the introduction of guidance documents at critical points within the research cycle might be one way to enhance the quality of such research. This article reports the findings from the piloting of a guidance document within the research commissioning process of a major funder of UK social research. The guidance document was positively received by researchers, the majority of whom reported it to be comprehensible, relevant and potentially useful in improving the quality of research proposals. However, a review of the submitted proposals suggested the guidance had had little impact on practice. While guidance may have a role to play, it will need to be strongly promoted by commissioners and other gatekeepers. Findings also suggest the possibility that guidance may discourage some researchers from engaging with ethnicity if it raises problems without solutions; highlighting the need for complementary investments in research capacity development in this area

Metal abundances and ionization conditions in a possibly dust-free damped Ly-alpha system at z=2.3

We have obtained a high resolution, high S/N UVES spectrum of the bright QSO HE2243-6031 to analyze the damped Ly-alpha system (DLA) observed at z=2.33. The metallicity of this system is 1/12 solar at a neutral hydrogen column density of log N(HI)=20.7. From the observed ratios [Zn/Cr]=-0.01+/-0.05 and [S/Si]=-0.06+/-0.03$ we conclude that dust is very likely absent from the ISM of this protogalaxy. We observe an enhancement of the alpha/Fe-peak ratios of +0.2 dex for various elements, a marked odd-even effect in Mn, and a strong underabundance of N relative to Si and S, [N/Si,S]=-1 at [Si/H]=-0.86. All of these ratios support an environment that is in an early evolutionary stage, where the onset of star formation has begun only shortly before the DLA was observed. We also perform a cloud-by-cloud analysis -- without precedent at high redshift -- and find a tight correlation of all low-ionization species with respect to FeII extending over 2.5 orders of magnitude in N(FeII). We interpret this trend as being due to homogeneous physical conditions (very mild ionization effects, common dust-destruction histories, same chemical composition) and propose that this line of sight encounters absorbing clouds that share a common environment. In addition, photoionization models show that these single clouds are shielded from the external ionizing radiation, so the fraction of ionized gas is small and, except for argon, does not influence the measured metal abundances. The observed AlIII/low-ion ratios suggest the mildly ionized gas occurs in shells surrounding neutral cores of AlII.Comment: To be published in A&

A bone grease processing station at the Mitchell Prehistoric Indian Village: archaeological evidence for the exploitation of bone fats

© Association for Environmental Archaeology 2015. Author's accepted manuscript version deposited in accordance with SHERPA RoMEO guidelines. The definitive version is available at http://www.maneyonline.com/doi/abs/10.1179/1749631414Y.0000000035.Recent excavations at the Mitchell Prehistoric Indian Village, an Initial Middle Missouri site in Mitchell, South Dakota have revealed a large, clay-lined feature filled with fractured and fragmented bison bones. Fracture and fragmentation analysis, along with taphonomic evidence, suggests that the bones preserved within the feature represent evidence of prehistoric bone marrow and bone grease exploitation. Further, the character of the feature suggests that it served as a bone grease processing station. Bone fat exploitation is an activity that is frequently cited as a causal explanation for the nature of many fractured and fragmented bone assemblages in prehistory, and zooarchaeological assemblages have frequently been studied as evidence of bone fat exploitation. The Mitchell example provides some of the first direct, in-situ archaeological evidence of a bone grease processing feature, and this interpretation is sustained by substantial analytical evidence suggesting bone fat exploitation. This new evidence provides a clearer concept of the nature of bone fat exploitation in prehistory as well as an indication of the scale and degree to which bone grease exploitation occurred at the Mitchell site. Finally, this research demonstrates the importance of careful zooarchaeological and taphonomic analysis for the interpretation of both artifactual remains as well as archaeological features

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’

Further Evidence for Cosmological Evolution of the Fine Structure Constant

We describe the results of a search for time variability of the fine structure constant, alpha, using absorption systems in the spectra of distant quasars. Three large optical datasets and two 21cm/mm absorption systems provide four independent samples, spanning 23% to 87% of the age of the universe. Each sample yields a smaller alpha in the past and the optical sample shows a 4-sigma deviation: da/a = -0.72 +/- 0.18 x 10^{-5} over the redshift range 0.5 < z < 3.5. We find no systematic effects which can explain our results. The only potentially significant systematic effects push da/a towards positive values, i.e. our results would become more significant were we to correct for them.Comment: 5 pages, 1 figure. Published in Phys. Rev. Lett. Small changes to discussion, added an acknowledgement and a referenc

Determining the effect of drying time on phosphorus solubilization from three agricultural soils under climate change scenarios

Climate projections for the future indicate that the United Kingdom will experience hotter, drier summers and warmer, wetter winters, bringing longer dry periods followed by rewetting. This will result in changes in phosphorus (P) mobilization patterns that will influence the transfer of P from land to water. We tested the hypothesis that changes in the future patterns of drying–rewetting will affect the amount of soluble reactive phosphorus (SRP) solubilized from soil. Estimations of dry period characteristics (duration and temperature) under current and predicted climate were determined using data from the UK Climate Projections (UKCP09) Weather Generator tool. Three soils (sieved 25°C are predicted in some places and dry periods of 30 to 90 d extremes are predicted. Combining the frequency of projected dry periods with the SRP concentration in leachate suggests that this may result overall in increased mobilization of P; however, critical breakpoints of 6.9 to 14.5 d dry occur wherein up to 28% more SRP can be solubilized following a rapid rewetting event. The precise cause of this increase could not be identified and warrants further investigation as the process is not currently included in P transfer models

Riverbed sediments buffer phosphorus concentrations downstream of sewage treatment works across the River Wensum catchment, UK

Purpose: Wastewater effluent discharged into rivers from sewage treatment works (STWs) represents one of the most important point sources of soluble reactive phosphorus (SRP) pollution and is a major driver of freshwater eutrophication. In this study, we assess the ability of riverbed sediments to act as a self-regulating buffering system to reduce SRP dissolved in the water column downstream of STW outflows. Materials and methods: River water and riverbed sediment samples were collected from 10 tributary outlets across the River Wensum catchment, Norfolk, UK, at monthly intervals between July and October 2016, such that 40 sediment and 40 water samples were collected in total. Of these locations, five were located downstream of STWs and five were on tributaries without STWs. Dissolved SRP concentrations were analysed and the Equilibrium Phosphorus Concentration (EPC0) of each sediment sample was measured to determine whether riverbed sediments were acting as net sources or sinks of SRP. Results and discussion: The mean SRP concentration downstream of STWs (382 µg P L-1) was double that of sites without a STW (185 µg P L-1), whilst the mean EPC0 for effluent impacted sites (105 µg P L-1) was 70% higher than that recorded at unaffected sites (62 µg P L-1). Regardless of STW influence, riverbed sediments across all 10 sites almost always acted as net sinks for SRP from the overlying water column. This was particularly true at sites downstream of STWs which displayed enhanced potential to buffer the river against increases in SRP released in sewage effluent. Conclusions: Despite EPC0 values revealing riverbed sediments were consistently acting as sinks for SRP, elevated SRP concentrations downstream of STWs clearly demonstrate the sediments have insufficient SRP sorption capacity to completely buffer the river against effluent discharge. Consequently, SRP concentrations across the catchment continue to exceed recommended standards for good chemical status, thus emphasising the need for enhanced mitigation efforts at STWs to minimise riverine phosphorus loading