179 research outputs found
Assessment of Spatial Variation of Groundwater Quality in a Mining Basin
Assessment of groundwater quality is vital for the sustainable safe use of this inimitable
resource. However, describing the overall groundwater quality condition—particularly in a mining
basin—is more complicated due to the spatial variability of multiple contaminants and the wide range
of indicators found in these areas. This study applies a geographic information system (GIS)-based
groundwater quality index (GQI) to assess water quality in a mining basin. The study synthesized
nine different water quality parameters available—nitrate, sulphate, chloride, sodium, magnesium,
calcium, dissolved mineral solids, potassium, and floride (NO−, SO2−, Cl−, Na+, Mg2+, Ca2+, DMS, 34
K+ and F−)—from 90 boreholes across the basin by indexing them numerically relative to the World Health Organization standards. The study compared data from 2006 and 2011. The produced map indicated a lower GQI of 67 in 2011 compared to 72 in 2006. The maximum GQI of 84.4 calculated using only three parameters (Mg2+, K+ and F−) compared well with the GQI of 84.6 obtained using all nine parameters. A noticeable declining groundwater quality trend was observed in most parts of the basin, especially in the south-western and the northern parts of the basin. The temporal variation between the GQIs for 2006 and 2011 indicated variable groundwater quality (coefficient of variation = 15–30%) in areas around the mining field, and even more variability (coefficient of variation >30%) in the south-western and eastern parts of the basin
Degradation and remobilization of endogenous retroviruses by recombination during the earliest stages of a germ-line invasion
Endogenous retroviruses (ERVs) are proviral sequences that result from colonization of the host germ line by exogenous retroviruses. The majority of ERVs represent defective retroviral copies. However, for most ERVs, endogenization occurred millions of years ago, obscuring the stages by which ERVs become defective and the changes in both virus and host important to the process. The koala retrovirus, KoRV, only recently began invading the germ line of the koala (Phascolarctos cinereus), permitting analysis of retroviral endogenization on a prospective basis. Here, we report that recombination with host genomic elements disrupts retroviruses during the earliest stages of germ-line invasion. One type of recombinant, designated recKoRV1, was formed by recombination of KoRV with an older degraded retroelement. Many genomic copies of recKoRV1 were detected across koalas. The prevalence of recKoRV1 was higher in northern than in southern Australian koalas, as is the case for KoRV, with differences in recKoRV1 prevalence, but not KoRV prevalence, between inland and coastal New South Wales. At least 15 additional different recombination events between KoRV and the older endogenous retroelement generated distinct recKoRVs with different geographic distributions. All of the identified recombinant viruses appear to have arisen independently and have highly disrupted ORFs, which suggests that recombination with existing degraded endogenous retroelements may be a means by which replication-competent ERVs that enter the germ line are degraded
Exile Vol. XLII No. 2
40th Year
Title Page i
Epigraph by Ezra Pound ii
Table of Contents ii
Editorial Board iii
frying fritters by Liz Bolyard \u2796 1
For Katherine by Carl Boon \u2796 1
poem paint by alex e blazer \u2797 2-3
Leftover Roses by Melissa Bostrom \u2796 4-12
O.J. (artwork) by Todd Gys \u2799 13
Untitled by Adrienne Fair \u2796 14-15
Hills by Liz Bolyard \u2796 16
A Serious Discussion with Ed Shim by Carl Boon \u2796 17
Untitled by David Kendall \u2796 18-19
Brave River by Nikole Hobbs \u2799 20-21
a wavy wail by alex e blazer \u2797 22-23
Misplaced by Tyler Smith \u2797 24
Imogene by Erin Lott \u2796 25-26
Why I can\u27t sleep at night by Colin Bossen \u2798 27
A Lovesong Never Realised by Matthew Rump \u2798 28
Contributors\u27 Notes 29-30
Special thanks to EPI Printing of Livonia, Michigan and Graphic Concepts Unlimited of Okemos, Michigan for helping to make this issue possible. -iii
Cover art The Longest Neck by Todd Gys -ii
nIFTy galaxy cluster simulations - IV. Quantifying the influence of baryons on halo properties
Building on the initial results of the nIFTy simulated galaxy cluster comparison, we compare
and contrast the impact of baryonic physics with a single massive galaxy cluster, run with 11
state-of-the-art codes, spanning adaptive mesh, moving mesh, classic and modern smoothed
particle hydrodynamics (SPH) approaches. For each code represented we have a dark-matteronly
(DM) and non-radiative (NR) version of the cluster, as well as a full physics (FP) version
for a subset of the codes. We compare both radial mass and kinematic profiles, as well as
global measures of the cluster (e.g. concentration, spin, shape), in the NR and FP runs with
that in the DM runs. Our analysis reveals good consistency (<≈
20 per cent) between global
properties of the cluster predicted by different codes when integrated quantities are measured
within the virial radius R200. However, we see larger differences for quantities within R2500,
especially in the FP runs. The radial profiles reveal a diversity, especially in the cluster centre,
between the NR runs, which can be understood straightforwardly from the division of codes
into classic SPH and non-classic SPH (including the modern SPH, adaptive and moving mesh
codes); and between the FP runs, which can also be understood broadly from the division
of codes into those that include active galactic nucleus feedback and those that do not. The
variation with respect to the median is much larger in the FP runs with different baryonic
physics prescriptions than in the NR runs with different hydrodynamics solvers
nIFTy galaxy cluster simulations – I. Dark matter and non-radiative models
We have simulated the formation of a galaxy cluster in a Ʌ cold dark matter universe using 13 different codes modelling only gravity and non-radiative hydrodynamics (RAMSES, ART, AREPO, HYDRA and nine incarnations of GADGET). This range of codes includes particle-based, moving and fixed mesh codes as well as both Eulerian and Lagrangian fluid schemes. The various GADGET implementations span classic and modern smoothed particle hydrodynamics (SPH) schemes. The goal of this comparison is to assess the reliability of cosmological hydrodynamical simulations of clusters in the simplest astrophysically relevant case, that in which the gas is assumed to be non-radiative. We compare images of the cluster at z = 0, global properties such as mass and radial profiles of various dynamical and thermodynamical quantities. The underlying gravitational framework can be aligned very accurately for all the codes allowing a detailed investigation of the differences that develop due to the various gas physics implementations employed. As expected, the mesh-based codes RAMSES, ART and AREPO form extended entropy cores in the gas with rising central gas temperatures. Those codes employing classic SPH schemes show falling entropy profiles all the way into the very centre with correspondingly rising density profiles and central temperature inversions. We show that methods with modern SPH schemes that allow entropy mixing span the range between these two extremes and the latest SPH variants produce gas entropy profiles that are essentially indistinguishable from those obtained with grid-based methods
Improving sightings-derived residency estimation for whale shark aggregations: A novel metric applied to a global data set
Anti-cancer Pro-inflammatory Effects of an IgE Antibody Targeting the Melanoma-associated Antigen Chondroitin Sulfate Proteoglycan 4
Towards an integrative, eco-evolutionary understanding of ecological novelty: studying and communicating interlinked effects of global change
Global change has complex eco-evolutionary consequences for organisms and ecosystems, but related concepts (e.g., novel ecosystems) do not cover their full range. Here we propose an umbrella concept of “ecological novelty” comprising (1) a site-specific and (2) an organism-centered, eco-evolutionary perspective. Under this umbrella, complementary options for studying and communicating effects of global change on organisms, ecosystems, and landscapes can be included in a toolbox. This allows researchers to address ecological novelty from different perspectives, e.g., by defining it based on (a) categorical or continuous measures, (b) reference conditions related to sites or organisms, and (c) types of human activities. We suggest striving for a descriptive, non-normative usage of the term “ecological novelty” in science. Normative evaluations and decisions about conservation policies or management are important, but require additional societal processes and engagement with multiple stakeholders
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