A trio of new Local Group galaxies with extreme properties

We report on the discovery of three new dwarf galaxies in the Local Group. These galaxies are found in new CFHT/MegaPrime g,i imaging of the south-western quadrant of M31, extending our extant survey area to include the majority of the southern hemisphere of M31's halo out to 150 kpc. All these galaxies have stellar populations which appear typical of dwarf spheroidal (dSph) systems. The first of these galaxies, Andromeda XVIII, is the most distant Local Group dwarf discovered in recent years, at ~1.4 Mpc from the Milky Way (~ 600 kpc from M31). The second galaxy, Andromeda XIX, a satellite of M31, is the most extended dwarf galaxy known in the Local Group, with a half-light radius of r_h ~ 1.7 kpc. This is approximately an order of magnitude larger than the typical half-light radius of many Milky Way dSphs, and reinforces the difference in scale sizes seen between the Milky Way and M31 dSphs (such that the M31 dwarfs are generally more extended than their Milky Way counterparts). The third galaxy, Andromeda XX, is one of the faintest galaxies so far discovered in the vicinity of M31, with an absolute magnitude of order M_V ~ -6.3. Andromeda XVIII, XIX and XX highlight different aspects of, and raise important questions regarding, the formation and evolution of galaxies at the extreme faint-end of the luminosity function. These findings indicate that we have not yet sampled the full parameter space occupied by dwarf galaxies, although this is an essential pre-requisite for successfully and consistently linking these systems to the predicted cosmological dark matter sub-structure.Comment: 32 pages, 7 figures (ApJ preprint format). Accepted for publication in Ap

Field Guide to the Geology of the Harlan County Lake Area, Harlan County, Nebraska — with a History of Events Leading to Construction of Harlan County Dam

The year 2002 will mark the fiftieth anniversary of completion of the Harlan County Dam and Multi-Purpose Reservoir. This seems a good time to write about the history of and reasons for building the dam, the effects of the dam and reservoir on the Republican River valley, and the geologic features seen along the shores of the lake and areas nearby. As many junior authors helped produced this educational circular, they are listed in the table of contents. All other sections were written by the senior author. Includes July 2016 update: Addendum of photographs showing fault traces on drought-exposed lake bottom. Cretaceous Niobrara Chalk Formation and the younger Pierre Shale are also shown. Table of Contents Introduction 1 Location 1 Republican River Floods 1 The Republican River Flood of 1935 - D R Mohlman 1 Cautionary Notes (sidebar) 1 Events After the Flood Leading to Creation of Harlan County Lake 9 Stormer Ford Dog Town (sidebar) 10 Water 10 Surface Water Hydrology - S Summerside 10 Shoreline Springs and Seeps - F: E Harvey and K J Warren 12 Introduction 12 Using Water Chemistry to Identify Spring and Seep Origin 1 2 Geology 15 General Conditions Leading to Good Exposures 15 Stratigraphy of Unconsolidated Sediments and Rock Strata 15 Cretaceous System - Upper Cretaceous Series 15 Niobrara Formation - Smoky Hill Chalk Member 15 Pierre Shale 15 Tertiary System - Miocene Series 16 Ogallala Group -Ash Hollow Formation 16 Quaternary System - Pleistocene Series 16 Crete (?) Formation (Sands and Gravels) 1 6 Loveland Loess 16 Gliman Canyon Formation 16 Peoria and Bignell Loesses 16 Quaternary System - Holocene (Recent) Series 1 6 Unnamed Fluvial, Eolian, and Colluvial Deposits 16 Paleontology of the Various Formations 16 Plants 16 Invertebrates - R K Pabian 17 Cretaceous Marine Fossils 17 Niobrara Formation 17 Foraminifers 17 Post-Devonian Stromatoporoids 1 9 Mollusks 19 Bivalves 19 Ammonites 19 Pierre Shale Formation 19 Bivalves 19 Ammonites 19 Quaternary - Pleistocene (Ice Age) Invertebrate Fossils 19 Vertebrate Fossils - R G Corner 24 Late Cretaceous Fossils 24 Niobrara Formation 24 Niobrara Fishes 24 Niobrara Mosasaurs 29 Pierre Shale Formation 30 Protosphyvaena gladius: Giant Mystery Fish 30 Pierre Mosasaurs 32 Late Miocene Ogallala Group 32 Bone Cove I Fauna 32 Bone Cove II Fauna 32 Quaternary - Pleistocene (Ice Age) 33 Crete (?) Sands and Gravels 33 Gilman Canyon Formation 33 Peoria Loess 35 Late Pleistocene Fauna 35 Late Pleistocene Environments 37 Geologic Processes Affecting the Strata 37 Modem and Ancient Landslides 37 Modern Landslides D A Eversoll 37 Ancient Landslides - D A Eversoll and R F Diffendal, Jr 39 Geologic Structures 41 Introduction and Previous Work 41 Angular Unconformities 45 Joints 45 Faults and Folds 45 Ancient Landscapes (Paleotopography) 50 Quaternary River Terraces 50 Concluding Remarks 50 References Cited 51 Glossary Keywords: flooding 1930s, vertebrate fossils, earthquake faults, landslides, groundwater qualit

Dietary iron intakes based on food composition data may underestimate the contribution of potentially exchangeable contaminant iron from soil

Iron intakes calculated from one-day weighed records were compared with those from same day analyzed duplicate diet composites collected from 120 Malawian women living in two rural districts with contrasting soil mineralogy and where threshing may contaminate cereals with soil iron. Soils and diet composites from the two districts were then subjected to a simulated gastrointestinal digestion and iron availability in the digests measured using a Caco-2 cell model. Median analyzed iron intakes (mg/d) were higher (p < 0.001) than calculated intakes in both Zombwe (16.6 vs. 10.1 mg/d) and Mikalango (29.6 vs. 19.1 mg/d), attributed to some soil contaminant iron based on high Al and Ti concentrations in diet composites. A small portion of iron in acidic soil from Zombwe, but not Mikalango calcareous soil, was bioavailable, as it induced ferritin expression in the cells, and may have contributed to higher plasma ferritin and total body iron for the Zombwe women reported earlier, despite lower iron intakes. In conclusion, iron intakes calculated from food composition data were underestimated, highlighting the importance of analyzing duplicate diet composites where extraneous contaminant iron from soil is likely. Acidic contaminant soil may make a small but useful contribution to iron nutrition

Using multiple hybrid spatial design network analysis to predict longitudinal effect of a major city centre redevelopment on pedestrian flows

Predicting how changes to the urban environment layout will affect the spatial distribution of pedestrian flows is important for environmental, social and economic sustainability. We present longitudinal evaluation of a model of the effect of urban environmental layout change in a city centre (Cardiff 2007–2010), on pedestrian flows. Our model can be classed as regression based direct demand using Multiple Hybrid Spatial Design Network Analysis (MH-sDNA) assignment, which bridges the gap between direct demand models, facility-based activity estimation and spatial network analysis (which can also be conceived as a pedestrian route assignment based direct demand model). Multiple theoretical flows are computed based on retail floor area: everywhere to shops, shop to shop, railway stations to shops and parking to shops. Route assignment, in contrast to the usual approach of shortest path only, is based on a hybrid of shortest path and least directional change (most direct) with a degree of randomization. The calibration process determines a suitable balance of theoretical flows to best match observed pedestrian flows, using generalized cross-validation to prevent overfit. Validation shows that the model successfully predicts the effect of layout change on flows of up to approx. 8000 pedestrians per hour based on counts spanning a 1 km2 city centre, calibrated on 2007 data and validated to 2010 and 2011. This is the first time, to our knowledge, that a pedestrian flow model with assignment has been evaluated for its ability to forecast the effect of urban layout changes over time

Genotypic and phenotypic characterization of enteric bacteria in an integrated population of swine and humans

In two longitudinal studies, we examined the transmission dynamics of antimicrobial resistance (AMR) in an integrated, semi-closed population of humans and swine

Beyond 'Global Production Networks': Australian Fashion Week's Trans-Sectoral Synergies

When studies of industrial organisation are informed by commodity chain, actor network, or global production network theories and focus on tracing commodity flows, social networks, or a combination of the two, they can easily overlook the less routine trans-sectoral associations that are crucial to the creation and realisation of value. This paper shifts attention to identifying the sites at which diverse specialisations meet to concentrate and amplify mutually reinforcing circuits of value. These valorisation processes are demonstrated in the case of Australian Fashion Week, an event in which multiple interests converge to synchronize different expressions of fashion ideas, actively construct fashion markets and enhance the value of a diverse range of fashionable commodities. Conceptualising these interconnected industries as components of a trans-sectoral fashion complex has implications for understanding regional development, world cities, production location, and the manner in which production systems “touch down” in different places