Using airborne LiDAR intensity to predict the organic potential of waterlogged deposits

An assessment of the predictive potential of backscettered lidar intensity to identigy organic preservation of waterlogged sediments in alluvial environments

Supernova Cosmology and the ESSENCE project

The proper usage of Type Ia supernovae (SNe Ia) as distance indicators has revolutionized cosmology, and added a new dominant component to the energy density of the Universe, dark energy. Following the discovery and confirmation era, the currently ongoing SNe Ia surveys aim to determine the properties of the dark energy. ESSENCE is a five year ground-based supernova survey aimed at finding and characterizing 200 SNe Ia in the redshift domain z=[0.2-0.8]. The goal of the project is to put constraints on the equation of state parameter, w, of the dark energy with an accuracy of <10%. This paper presents these ongoing efforts in the context of the current developments in observational cosmology.Comment: Submitted to EPS1

Cloning and expression of Burkholderia polyyne biosynthetic gene clusters in 2 Paraburkholderia hosts provides a strategy for biopesticide development

Burkholderia have potential as biocontrol agents because they encode diverse biosynthetic gene clusters (BGCs) for a range of antimicrobial metabolites. Given the opportunistic pathogenicity associated with Burkholderia species, heterologous BGC expression within non-pathogenic hosts is a strategy to construct safe biocontrol strains. We constructed a yeast-adapted Burkholderia-Escherichia shuttle vector (pMLBAD_yeast) with a yeast replication origin 2 μ and URA3 selection marker and optimised it for cloning BGCs using the in vivo recombination ability of Saccharomyces cerevisiae. Two Burkholderia polyyne BGCs, cepacin (13 kb) and caryoynencin (11 kb), were PCR-amplified as three overlapping fragments, cloned downstream of the pBAD arabinose promoter in pMLBAD_yeast and mobilised into Burkholderia and Paraburkholderia heterologous hosts. Paraburkholderia phytofirmans carrying the heterologous polyyne constructs displayed in vitro bioactivity against a variety of fungal and bacterial plant pathogens similar to the native polyyne producers. Thirteen Paraburkholderia strains with preferential growth at 30°C compared with 37°C were also identified, and four of these were amenable to genetic manipulation and heterologous expression of the caryoynencin construct. The cloning and successful heterologous expression of Burkholderia biosynthetic gene clusters within Paraburkholderia with restricted growth at 37°C opens avenues for engineering non-pathogenic biocontrol strains

CfA3: 185 Type Ia Supernova Light Curves from the CfA

We present multi-band photometry of 185 type-Ia supernovae (SN Ia), with over 11500 observations. These were acquired between 2001 and 2008 at the F. L. Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics (CfA). This sample contains the largest number of homogeneously-observed and reduced nearby SN Ia (z < 0.08) published to date. It more than doubles the nearby sample, bringing SN Ia cosmology to the point where systematic uncertainties dominate. Our natural system photometry has a precision of 0.02 mag or better in BVRIr'i' and roughly 0.04 mag in U for points brighter than 17.5 mag. We also estimate a systematic uncertainty of 0.03 mag in our SN Ia standard system BVRIr'i' photometry and 0.07 mag for U. Comparisons of our standard system photometry with published SN Ia light curves and comparison stars, where available for the same SN, reveal agreement at the level of a few hundredths mag in most cases. We find that 1991bg-like SN Ia are sufficiently distinct from other SN Ia in their color and light-curve-shape/luminosity relation that they should be treated separately in light-curve/distance fitter training samples. The CfA3 sample will contribute to the development of better light-curve/distance fitters, particularly in the few dozen cases where near-infrared photometry has been obtained and, together, can help disentangle host-galaxy reddening from intrinsic supernova color, reducing the systematic uncertainty in SN Ia distances due to dust.Comment: Accepted to the Astrophysical Journal. Minor changes from last version. Light curves, comparison star photometry, and passband tables are available at http://www.cfa.harvard.edu/supernova/CfA3

Airborne Remote Sensing of Aggregate Landscapes

This project investigated the potential of multispectral and hyperspectral methods of airborne remote sensing (RS) for the prospection of cultural, environmental and geoarchaeological remains in river valley floors. The project undertook systematic examination of Daedalus 1268 Airborne Thematic Mapper (ATM) and Compact Airborne Spectrographic Imager (CASI) multispectral data. AISA Eagle hyperspectral data for a small area were also examined. Work focused on the archaeologically rich, well documented aggregate landscapes of the middle Trent Valley, Nottinghamshire

Airborne LiDAR backscattered Laser Intensity Prediction of Organic Preservation

Lidar provides access to high resolution, high accuracy terrain information and as a secondary output a laser image of the land surface derived from measurements of the intensity of reflection of each backscattered laser pulse. Archaeological applications of Lidar have focused largely on its ability to provide a high resolution record of terrain variation, allowing the detection and mapping of subtle archaeological features mapping of fluvial geomorphology and its unique ability to penetrate vegetation cover to map underlying archaeological earthworks. Backscattered laser intensity measurements have largely escaped attention and little or no work has been undertaken to investigate intensity, which until now has been largely ignored both by archaeologists and by the lidar industry as a whole

Catchment Tributaries of the River Trent

This project involves geoarchaeological assessments of two of the principal tributary valleys of the Trent (the Rivers Dove and Idle) undertaken to assess the impact of their evolution on the main valley floor. Study of the Idle and Dove was complimented, to a limited extent, by consideration of two lesser valleys, (the Devon and the Dover Beck) with the overall aim of identifying landscapes and resources in these tributaries that might elucidate key issues in the study of the main Trent Valley

Predictive Modelling of Multi-Period Geoarchaeological Resources at a River Confluence

Predictive Modelling of Multi-Period Geoarchaeological Resources at a River confluence is an Aggregates Levy Sustainability Fund backed project led by principal investigators Professor Tony Brown, Dr Andy J Howard and Mr Keith Challis. The project takes as its study area the confluence of the Trent and Soar rivers in the East Midlands of the United Kingdom. The overall purpose of the project is to: (a) to establish a rigorous research model for the future development of predetermination designs for site evaluation, (b) to assess the effectiveness of various airborne and ground based remote sensing methods in alluvial environments, and (c) to derive relationships between pre-extraction site survey data and likely chronostratigraphic and environmental data as part of archaeological assessment. This research will assist regulatory bodies (i.e. County Councils) in demanding and specifying rapid evaluations of geoarchaeological potential as part of the implementation of PPG16