Updating predictive accident models of modern rural single carriageway A-roads

Reliable predictive accident models (PAMs) are essential to design and maintain safe road networks and yet the models most commonly used in the UK were derived using data collected 20 to 30 years ago. Given that the national personal injury accident total fell by some 30% in the last 25 years, while road traffic increased by over 60%, significant errors in scheme appraisal and evaluation based on the models currently in use seem inevitable. In this paper the temporal transferability of PAMs for modern rural single carriageway A-roads is investigated and their predictive performance is evaluated against a recent data set. Despite the age of these models, the PAMs for predicting the total accidents provide a remarkably good fit to recent data and these are more accurate than models where accidents are disaggregated by type. The performance of the models can be improved by calibrating them against recent data

A Spectral Classification System for Hydrogen-deficient Carbon Stars

Stellar spectral classification, and especially the Yerkes system, has been highly useful in the study of stars. While there is a currently accepted classification system for carbon stars, the subset of Hydrogen-deficient Carbon (HdC) stars has not been well described by such a system, due in part to their rarity and their variability. Here we present a new system for the classification of HdCs based on their spectra, which is made wholly on their observable appearance. We use a combination of dimensionality reduction and clustering algorithms with human classification to create such a system. We classify over half of the known sample of HdC stars using this, and roughly calibrate the temperatures of each class using their colors. Additionally, we express trends in the occurrence of certain spectral peculiarities such as the presence of Hydrogen and Lithium lines. We also present three previously unpublished spectra, and report the discovery of three new Galactic dustless HdC (dLHdC) stars and additionally discuss one especially unique star that appears to border between the hottest HdCs and the coolest Extreme Helium (EHe) stars.Comment: 30 pages, 18 figures, submitted to MNRA

Average seasonal changes in chlorophyll a in Icelandic waters

The standard algorithms used to derive sea surface chlorophyll a concentration from remotely sensed ocean colour data are based almost entirely on the measurements of surface water samples collected in open sea (case 1) waters which cover ~60% of the worlds oceans, where strong correlations between reflectance and chlorophyll concentration have been found. However, satellite chlorophyll data for waters outside the defined case 1 areas, but derived using standard calibrations, are frequently used without reference to local in situ measurements and despite well-known factors likely to lead to inaccuracy. In Icelandic waters, multiannual averages of 8-d composites of SeaWiFS chlorophyll concentration accounted for just 20% of the variance in a multiannual dataset of in situ chlorophyll a measurements. Nevertheless, applying penalized regression spline methodology to model the spatial and temporal patterns of in situ measurements, using satellite chlorophyll as one of the predictor variables, improved the correlation considerably. Day number, representing seasonal variation, accounted for substantial deviation between SeaWiFS and in situ estimates of surface chlorophyll. The final model, using bottom depth and bearing to the sampling location as well as the two variables mentioned above, explained 49% of the variance in the fitting dataset

Experimental Investigation of the Secondary and Backscatter Electron Emission From New Spacecraft Surface Materials

The emission of secondary and backscattered electrons influences spacecraft surface potentials and the surrounding plasma. Modern spacecraft use new materials for which secondary emission properties have been unavailable. In this work, the total electron yield (i.e., the sum of secondary and backscattered electron yields) was measured for niobium-C103 alloy, molybdenum Titanium, Zirconium, Molybdenum (TZM) alloy, tantalum-tungsten alloy, Elgiloy®, graphite lubricant (DAG 213®), and titanium nitride. The surface properties of tungsten were also measured for comparison with past test data. The materials were readied as spacecraft flight materials and temperature-treated ( annealed ) to predicted peak flight temperatures. The yield properties for 10 eV-5 keV incident electron energies for all samples were measured. Both unannealed and annealed states were tested, except DAG 213, which was only tested annealed. Three-parameter and four-parameter models were used to fit the secondary and backscattered electron yield data, respectively. The emitted electron energy distributions are also obtained and fit with a Chung-Everhart model for secondary electrons and a Gaussian function for backscattered electrons. The secondary and backscattered electrons\u27 current densities were calculated for different ambient plasma conditions. For ready reference, the normalized primary electron, secondary electron, and backscattered electron current densities versus ambient electron temperature were computed and plotted from 1 eV to 8 keV

Technical Report Series on Global Modeling and Data Assimilation, Volume 41 : GDIS Workshop Report

The workshop "An International Global Drought Information System Workshop: Next Steps" was held on 10-13 December 2014 in Pasadena, California. The more than 60 participants from 15 countries spanned the drought research community and included select representatives from applications communities as well as providers of regional and global drought information products. The workshop was sponsored and supported by the US National Integrated Drought Information System (NIDIS) program, the World Climate Research Program (WCRP: GEWEX, CLIVAR), the World Meteorological Organization (WMO), the Group on Earth Observations (GEO), the European Commission Joint Research Centre (JRC), the US Climate Variability and Predictability (CLIVAR) program, and the US National Oceanic and Atmospheric Administration (NOAA) programs on Modeling, Analysis, Predictions and Projections (MAPP) and Climate Variability & Predictability (CVP). NASA/JPL hosted the workshop with logistical support provided by the GEWEX program office. The goal of the workshop was to build on past Global Drought Information System (GDIS) progress toward developing an experimental global drought information system. Specific goals were threefold: (i) to review recent research results focused on understanding drought mechanisms and their predictability on a wide range of time scales and to identify gaps in understanding that could be addressed by coordinated research; (ii) to help ensure that WRCP research priorities mesh with efforts to build capacity to address drought at the regional level; and (iii) to produce an implementation plan for a short duration pilot project to demonstrate current GDIS capabilities. See http://www.wcrp-climate.org/gdis-wkshp-2014-objectives for more information

Aquatic live animal radiotracing studies for ecotoxicological applications : addressing fundamental methodological deficiencies

The use of live animal gamma radioisotope tracer techniques in the field of ecotoxicology allows laboratory studies to accurately monitor contaminant biokinetics in real time for an individual organism. However, methods used in published studies for aquatic organisms are rarely described in sufficient detail to allow for study replication or an assessment of the errors associated with live animal radioanalysis to be identified. We evaluate the influence of some important methodological deficiencies through an overview of the literature on live aquatic animal radiotracer techniques and through the results obtained from our radiotracer studies on four aquatic invertebrate species. The main factors discussed are animal rinsing, radioanalysis and geometry corrections. We provide examples of three main techniques in live aquatic animal radiotracer studies to improve data quality control and demonstrate why each technique is crucial in interpreting the data from such studies. The animal rinsing technique is also relevant to non-radioisotope tracer studies, especially those involving nanoparticles. We present clear guidance on how to perform each technique and explain the importance of proper reporting of the validation of each technique for individual studies. In this paper we describe methods that are often used in lab-based radioecology studies but are rarely described in great detail. We hope that this paper will act as the basis for standard operating procedures for future radioecology studies to improve study replication and data quality control

A review of camera trapping for conservation behaviour research

An understanding of animal behaviour is important if conservation initiatives are to be effective. However, quantifying the behaviour of wild animals presents significant challenges. Remote-sensing camera traps are becoming increasingly popular survey instruments that have been used to non-invasively study a variety of animal behaviours, yielding key insights into behavioural repertoires. They are well suited to ethological studies and provide considerable opportunities for generating conservation-relevant behavioural data if novel and robust methodological and analytical solutions can be developed. This paper reviews the current state of camera-trap-based ethological studies, describes new and emerging directions in camera-based conservation behaviour, and highlights a number of limitations and considerations of particular relevance for camerabased studies. Three promising areas of study are discussed: (1) documenting anthropogenic impacts on behaviour; (2) incorporating behavioural responses into management planning and (3) using behavioural indicators such as giving up densities and daily activity patterns. We emphasize the importance of reporting methodological details, utilizing emerging camera trap metadata standards and central data repositories for facilitating reproducibility, comparison and synthesis across studies. Behavioural studies using camera traps are in their infancy; the full potential of the technology is as yet unrealized. Researchers are encouraged to embrace conservation-driven hypotheses in order to meet future challenges and improve the efficacy of conservation and management processes.The contribution of M.D. Wood was supported by the TREE project (www.ceh.ac. uk/TREE) funded by the Natural Environment Research Council (NERC), Environment Agency and Radioactive Waste Management Limited. The contributions of C.M.V. Finlay were supported by the Red Squirrels United project (http://www.redsquirrelsunited.org.uk/) funded by EU Life and Heritage Lottery Fund.http://zslpublications.onlinelibrary.wiley.com/hub/journal/10.1002/(ISSN)2056-3485am2017Centre for Wildlife Managemen

Calibration of myocardial T2 and T1 against iron concentration.

BACKGROUND: The assessment of myocardial iron using T2* cardiovascular magnetic resonance (CMR) has been validated and calibrated, and is in clinical use. However, there is very limited data assessing the relaxation parameters T1 and T2 for measurement of human myocardial iron. METHODS: Twelve hearts were examined from transfusion-dependent patients: 11 with end-stage heart failure, either following death (n=7) or cardiac transplantation (n=4), and 1 heart from a patient who died from a stroke with no cardiac iron loading. Ex-vivo R1 and R2 measurements (R1=1/T1 and R2=1/T2) at 1.5 Tesla were compared with myocardial iron concentration measured using inductively coupled plasma atomic emission spectroscopy. RESULTS: From a single myocardial slice in formalin which was repeatedly examined, a modest decrease in T2 was observed with time, from mean (± SD) 23.7 ± 0.93 ms at baseline (13 days after death and formalin fixation) to 18.5 ± 1.41 ms at day 566 (p<0.001). Raw T2 values were therefore adjusted to correct for this fall over time. Myocardial R2 was correlated with iron concentration [Fe] (R2 0.566, p<0.001), but the correlation was stronger between LnR2 and Ln[Fe] (R2 0.790, p<0.001). The relation was [Fe] = 5081•(T2)-2.22 between T2 (ms) and myocardial iron (mg/g dry weight). Analysis of T1 proved challenging with a dichotomous distribution of T1, with very short T1 (mean 72.3 ± 25.8 ms) that was independent of iron concentration in all hearts stored in formalin for greater than 12 months. In the remaining hearts stored for <10 weeks prior to scanning, LnR1 and iron concentration were correlated but with marked scatter (R2 0.517, p<0.001). A linear relationship was present between T1 and T2 in the hearts stored for a short period (R2 0.657, p<0.001). CONCLUSION: Myocardial T2 correlates well with myocardial iron concentration, which raises the possibility that T2 may provide additive information to T2* for patients with myocardial siderosis. However, ex-vivo T1 measurements are less reliable due to the severe chemical effects of formalin on T1 shortening, and therefore T1 calibration may only be practical from in-vivo human studies

A plethora of new R Coronae Borealis stars discovered from a dedicated spectroscopic follow-up survey

Context. It is more and more suspected that R Coronae Borealis (RCB) stars - rare hydrogen-deficient and carbon-rich supergiant stars - are the products of mergers of CO/He white-dwarf binary systems in the intermediate mass regime (0.6 < MTot < 1.2 M). Following the merger, a short-lived cool supergiant phase starts. RCB stars are extremely rare as only 77 have hitherto been known in the Galaxy, while up to 1000 have been predicted from population synthesis models. Aims. The goal is to significantly increase the number of known RCB stars in order to better understand their evolutionary paths, their spatial distribution, and their formation rate in the context of population synthesis results. A list of 2356 RCB star candidates was selected using infrared colours from the all-sky 2MASS and WISE surveys. The objective is to follow them up spectroscopically to classify the candidates and, thus, to distinguish RCB stars from other dust-producing stars. Methods. A series of brightness and colour-colour cuts that were used as selection criteria were then tested using the sample of known Galactic and Magellanic RCB stars. RCB spectral energy distribution models were also used to understand the effects of each selection criterion in terms of circumstellar shell temperature. Optical, low-resolution spectra were obtained for nearly 500 of the candidate stars. These spectra were compared to synthetic spectra from a new grid of MARCs hydrogen-deficient atmospheric models. This allowed us to define a spectroscopic classification system for RCB stars depending on their effective temperature and photometric status. Results. This programme has found 45 new RCB stars, including 30 Cold (4000 15 000 K). Forty of these belong to the Milky Way and five are located in the Magellanic Clouds. We also confirmed that the candidate KDM 5651 is indeed a new RCB star, increasing the total number of Magellanic RCB stars to 30. Conclusions. We increased the total number of RCB stars known by ∼50%, bringing it up to 147. In addition, we compiled a list of 14 strong RCB candidates, most certainly observed during a dust obscuration phase. From the detection efficiency and success rate so far, we estimate that there should be no more than 500 RCB stars existing in the Milky Way, all HdC stars included.This research was conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020, and we acknowledge also financial support from “Programme National de Physique Stellaire” (PNPS) of CNRS/INSU, France. PT thanks the MARCS team in Uppsala (Sweden) for kindly providing a grid of hydrogen-deficient stellar models and the french embassy in Sweden for allowing a collaborative visit funded by the program TOR. We also thanks the team located at Siding Spring Observatory that keeps the 2.3 m telescope and its intruments is good shape, as well as the engineer, computer and technician teams located at Mount Stromlo Observatory that have facilitate the observations for the past 10 years. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This publication also makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Centre, California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. Finally, we heartily thank the OGLE team that have provided light curves for many of our candidates. The OGLE project has received funding from the National Science Centre, Poland, grant MAESTRO 2014/14/A/ST9/00121 to A.U