761 research outputs found
Investigating the traffic-related environmental impacts of hydraulic-fracturing (fracking) operations
Hydraulic fracturing (fracking) has been used extensively in the US and Canada since the 1950s and offers the potential for significant new sources of oil and gas supply. Numerous other countries around the world (including the UK, Germany, China, South Africa, Australia and Argentina) are now giving serious consideration to sanctioning the technique to provide additional security over the future supply of domestic energy. However, relatively high population densities in many countries and the potential negative environmental impacts that may be associated with fracking operations has stimulated controversy and significant public debate regarding if and where fracking should be permitted. Road traffic generated by fracking operations is one possible source of environmental impact whose significance has, until now, been largely neglected in the available literature. This paper therefore presents a scoping-level environmental assessment for individual and groups of fracking sites using a newly-created Traffic Impacts Model (TIM). The model produces estimates of the traffic-related impacts of fracking on greenhouse gas emissions, local air quality emissions, noise and road pavement wear, using a range of hypothetical fracking scenarios to quantify changes in impacts against baseline levels.
Results suggest that the local impacts of a single well pad may be short duration but large magnitude. That is, whilst single digit percentile increases in emissions of CO2, NOx and PM are estimated for the period from start of construction to pad completion (potentially several months or years), excess emissions of NOx on individual days of peak activity can reach 30% over baseline. Likewise, excess noise emissions appear negligible (< 1 dBA) when normalised over the completion period, but may be considerable (+ 3.4 dBA) in particular hours, especially in night-time periods. Larger, regional scale modelling of pad development scenarios over a multi-decade time horizon give modest CO2 emissions that vary between 2.5 and 160.4 kT, dependent on the number of wells, and individual well fracking water and flowback waste requirements. The TIM model is designed to be adaptable to any geographic area where the required input data are available (such as fleet characteristics, road type and quality), and we suggest could be deployed as a tool to help reach more informed decisions regarding where and how fracking might take place taking into account the likely scale of traffic-related environmental impacts
Growing Up in Civil Rights Richmond: A Community Remembers
Published on the occasion of the exhibition Growing Up in Civil Rights Richmond: A Community Remembers, Joel and Lila Harnett Museum of Art, University of Richmond Museums, January 17 to May 10, 2019.
Organized by the University of Richmond Museums, the exhibition was developed by Ashley Kistler, independent curator, and Laura Browder, Tyler and Alice Haynes Professor of American Studies, University of Richmond. The exhibition, related programs, and publication are made possible in part with funds from the Louis S. Booth Arts Fund and with support from the University’s Cultural Affairs Committee. The printed exhibition catalogue was made possible in part with support from the Elizabeth Firestone Graham Foundation. Published by University of Richmond Museums, Richmond, Virginia.
Edited by N. Elizabeth Schlatter, University of Richmond Museums, and Ashley Kistler, independent curator. Designed by DELANO Creative, Richmond, Virginia Printed by Worth Higgins & Associates Inc., Richmond, Virginia. Cover: Brian Palmer (American, born 1964), Deborah Taylor, Franklin Military Academy (formerly East End High School), 2017, archival inkjet print on paper, 30 x 40 inches, lent courtesy of the artist.https://scholarship.richmond.edu/exhibition-catalogs/1006/thumbnail.jp
Book reviews
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47962/1/11406_2006_Article_BF02378973.pd
Genetic analysis of glutamate receptors in Drosophila reveals a retrograde signal regulating presynaptic transmitter release
Postsynaptic sensitivity to glutamate was genetically manipulated at the Drosophila neuromuscular junction (NMJ) to test whether postsynaptic activity can regulate presynaptic function during development. We cloned the gene encoding a second muscle-specific glutamate receptor, DGluRIIB, which is closely related to the previously identified DGluRIIA and located adjacent to it in the genome. Mutations that eliminate DGluRIIA (but not DGluRIIB) or transgenic constructs that increase DGluRIIA expression were generated. When DGluRIIA is missing, the response of the muscle to a single vesicle of transmitter is substantially de- creased. However, the responseof the muscle to nerve stimulation is normal because quantal content is significantly increased. Thus, a decrease in postsynaptic receptors leads to an increase in presynaptic transmitter release, indicating that postsynaptic activity controls a retrograde signal that regulates presynaptic function
Lunar Surface Engineering Properties Experiment Definition
The objectives of the research under this contract are to define geological and engineering problems associated with lunar exploration that depend on the knowledge of the mechanical properties of soil and rock for solution and to perform critical evaluation of available information relating to the composition, structure, and engineering properties of lunar surface materials.Submitted to : National Aeronautics and Space Administration, George C. Marshall Space Flight Center. Contract Number NAS 8-21432. Control Number DCN l-8-28-00056(IF)By James K. Mitchell, Richard E. Goodman, William N. Houston, Paul A. WitherspoonLunar soil simulation / W. N. Houston, L. I. Narniq, and J. K. Mitchell -- Friction angle of lunar surface soils estimated from boulder tracks / H. J. Hovland and J. K. Mitchell -- Trafficability of the lunar surface / J. B. Thompson and J. K. Mitchell -- Chemical impregnation techniques as related to lunar engineering applications / T. s. Vinson and J. K. Mitchell -- Failure of a borehole in soil or rock under dilatometer loading and under borehole jack loading / T. K. Van and R. E. Goodman -- Appendix - Detailed description of model studies / K. Drozd, T. K. Van, and R. E. Goodman -- Studies on fluid conductivity of lunar surface materials / D. F. Katz, D. R. Willis, and P. A. Witherspoon.Second quarterly repor
HIV associated Lymphocytic Interstitial Pneumonia: a clinical, histological and radiographic study from an HIV endemic resource-poor setting
Background: There is a paucity of clinical and histopathological data about HIV-associated lymphocytic interstitial pneumonitis (LIP) in adults from HIV endemic settings. The role of Ebstein-Barr virus (EBV) in the pathogenesis remains unclear.
Methods: We reviewed the clinical, radiographic and histopathological features of suspected adult LIP cases at the Groote Schuur Hospital, Cape Town South Africa, over a 6Â year period. Archived tissue sections were stained for CD3, CD4, CD8, CD20 and LMP-1 antigen (an EBV marker).
Results: 42 cases of suspected LIP(100% HIV-infected) were identified. 75% of patients were empirically treated for TB prior to being referred to the chest service for further investigation. Tissue samples were obtained using trans-bronchial biopsy. 13/42 were classified as definite LIP (lymphocytic infiltrate with no alternative diagnosis), 19/42 probable LIP (lymphocytic infiltrate but evidence of anthracosis or fibrosis) and 10 as non-LIP (alternative histological diagnosis). Those with definite LIP were predominantly young females (85%) with a median CD4 count of 194 (IQR 119–359). Clinical or radiological features had poor predictive value for LIP. Histologically, the lymphocytic infiltrate comprised mainly B cells and CD8 T cells. The frequency of positive EBV LMP-1 antigen staining was similar in definite and non- LIP patients [(2/13 (15%) vs. 3/10 (30%); p = 0.52].
Conclusions: In a HIV endemic setting adult HIV-associated LIP occurs predominantly in young women. The diagnosis can often be made on transbronchial biopsy and is characterized by a predominant CD8 T cell infiltrate. No association with EBV antigen was found
The formation of very wide binaries during the star cluster dissolution phase
Over the past few decades, numerous wide (>1000 au) binaries in the Galactic
field and halo have been discovered. Their existence cannot be explained by the
process of star formation or by dynamical interactions in the field, and their
origin has long been a mystery. We explain the origin of these wide binaries by
formation during the dissolution phase of young star clusters: an initially
unbound pair of stars may form a binary when their distance in phase-space is
small. Using N-body simulations, we find that the resulting wide binary
fraction in the semi-major axis range 1000 au - 0.1 pc for individual clusters
is 1-30%, depending on the initial conditions. The existence of numerous wide
binaries in the field is consistent with observational evidence that most
clusters start out with a large degree of substructure. The wide binary
fraction decreases strongly with increasing cluster mass, and the semi-major
axis of the newly formed binaries is determined by the initial cluster size.
The resulting eccentricity distribution is thermal, and the mass ratio
distribution is consistent with gravitationally-focused random pairing. As a
large fraction of the stars form in primordial binaries, we predict that a
large number of the observed 'wide binaries' are in fact triple or quadruple
systems. By integrating over the initial cluster mass distribution, we predict
a binary fraction of a few per cent in the semi-major axis range 1000 au - 0.1
pc in the Galactic field, which is smaller than the observed wide binary
fraction. However, this discrepancy may be solved when we consider a broad
range of cluster morphologies.Comment: 14 pages, 12 figures, accepted by MNRA
Is using the strengths and difficulties questionnaire in a community sample the optimal way to assess mental health functioning?
An important characteristic of a screening tool is its discriminant ability or the measure’s accuracy to distinguish between those with and without mental health problems. The current study examined the inter-rater agreement and screening concordance of the parent and teacher versions of SDQ at scale, subscale and item-levels, with the view of identifying the items that have the most informant discrepancies; and determining whether the concordance between parent and teacher reports on some items has the potential to influence decision making. Cross-sectional data from parent and teacher reports of the mental health functioning of a community sample of 299 students with and without disabilities from 75 different primary schools in Perth, Western Australia were analysed. The study found that: a) Intraclass correlations between parent and teacher ratings of children’s mental health using the SDQ at person level was fair on individual child level; b) The SDQ only demonstrated clinical utility when there was agreement between teacher and parent reports using the possible or 90% dichotomisation system; and c) Three individual items had positive likelihood ratio scores indicating clinical utility. Of note was the finding that the negative likelihood ratio or likelihood of disregarding the absence of a condition when both parents and teachers rate the item as absent was not significant. Taken together, these findings suggest that the SDQ is not optimised for use in community samples and that further psychometric evaluation of the SDQ in this context is clearly warranted
Public health professionals' perceptions toward provision of health protection in England: a survey of expectations of Primary Care Trusts and Health Protection Units in the delivery of health protection
BACKGROUND: Effective health protection requires systematised responses with clear accountabilities. In England, Primary Care Trusts and the Health Protection Agency both have statutory responsibilities for health protection. A Memorandum of Understanding identifies responsibilities of both parties, but there is a potential lack of clarity about responsibility for specific health protection functions. We aimed to investigate professionals' perceptions of responsibility for different health protection functions, to inform future guidance for, and organisation of, health protection in England. METHODS: We sent a postal questionnaire to all health protection professionals in England from the following groups: (a) Directors of Public Health in Primary Care Trusts; (b) Directors of Health Protection Units within the Health Protection Agency; (c) Directors of Public Health in Strategic Health Authorities and; (d) Regional Directors of the Health Protection Agency RESULTS: The response rate exceeded 70%. Variations in perceptions of who should be, and who is, delivering health protection functions were observed within, and between, the professional groups (a)-(d). Concordance in views of which organisation should, and which does deliver was high (≥90%) for 6 of 18 health protection functions, but much lower (≤80%) for 6 other functions, including managing the implications of a case of meningitis out of hours, of landfill environmental contamination, vaccination in response to mumps outbreaks, nursing home infection control, monitoring sexually transmitted infections and immunisation training for primary care staff. The proportion of respondents reporting that they felt confident most or all of the time in the safe delivery of a health protection function was strongly correlated with the concordance (r = 0.65, P = 0.0038). CONCLUSION: Whilst we studied professionals' perceptions, rather than actual responses to incidents, our study suggests that there are important areas of health protection where consistent understanding of responsibility for delivery is lacking. There are opportunities to clarify the responsibility for health protection in England, perhaps learning from the approaches used for those health protection functions where we found consistent perceptions of accountability
Milestones in the Observations of Cosmic Magnetic Fields
Magnetic fields are observed everywhere in the universe. In this review, we
concentrate on the observational aspects of the magnetic fields of Galactic and
extragalactic objects. Readers can follow the milestones in the observations of
cosmic magnetic fields obtained from the most important tracers of magnetic
fields, namely, the star-light polarization, the Zeeman effect, the rotation
measures (RMs, hereafter) of extragalactic radio sources, the pulsar RMs, radio
polarization observations, as well as the newly implemented sub-mm and mm
polarization capabilities.
(Another long paragraph is omitted due to the limited space here)Comment: Invited Review (ChJA&A); 32 pages. Sorry if your significant
contributions in this area were not mentioned. Published pdf & ps files (with
high quality figures) now availble at http://www.chjaa.org/2002_2_4.ht
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