7,098 research outputs found
A review of knowledge of the potential impacts of GMOs on organic agriculture
The organic movement believes that organic agriculture, by its nature, cannot involve the use of genetically modified organisms (GMOs). This has been incorporated into EU regulations which state that there is no place in organic agriculture for GMOs. The aim in this review is to consider the ways in which the use of GMOs in agriculture in the UK and internationally might impact on organic farming. It does not address the controversy about the rights or wrongs of GMO’s per se. The subjects covered are based on a set of questions raised at the beginning of the study. The review is based primarily on evidence from peer-reviewed literature.
The report is based on a number of themes, as follows:
• Fate of DNA in soil
• Fate of DNA in livestock feed and possible impact of GM feed
• Fate of DNA in slurry, manure, compost and mulch
• Impact of herbicide tolerant crops
• Impact of pest and disease resistant crops
• Safety of promoters
• DNA transfer in pollen and seeds
• Horizontal gene transfer
• Impact of scale
The report’s Executive Summary includes summaries of the findings on each of these themes
Short oestrous cycles in sheep during anoestrus involve defects in progesterone biosynthesis and luteal neovascularisation
Anoestrous ewes can be induced to ovulate by the socio-sexual, 'ram effect'. However, in some ewes the induced ovulation is followed by an abnormally short luteal phase causing a so called, "short cycle". The defect responsible for this luteal dysfunction has not been identified. In this experiment we investigated ovarian and uterine factors implicated in male-induced short cycles in anoestrus ewes using a combined endocrine and molecular strategy. Prior to ovulation, we were able to detect a moderate loss of thecal expression of steroid acute regulatory protein (STAR) in ewes that had not received progesterone priming (which prevents short cycles). At and following ovulation we were able to identify significant loss of expression of genes coding key proteins involved in the biosynthesis of progesterone (STAR, CYP11A1, HSD3B) as well as genes coding proteins critical for vascular development during early luteal development (VEGFA, VEGFR2) suggesting dysfunction in at least two pathways critical for normal luteal function. Furthermore, these changes were associated with a significant reduction of progesterone production and luteal weight. Additionally, we cast doubt on the proposed uterine-mediated effect of prostaglandin F2α as a cause of short cycles by demonstrating both the dysregulation of luteal expression of the PGF receptor, which mediates the luteal effects of PGF2α, and by finding no significant changes in the circulating concentrations of PGFM, the principal metabolite of PGF2α in ewes with short cycles. This study is the first of its kind to examine concurrently, the endocrine and molecular events in the follicular and early luteal stages of the short cycle
Creating a Culture of Grant Writing in a Multi-Campus Academic Setting
Grant writing is more important than ever in an era of “proving our worth” at academic libraries. For small libraries wanting to provide their communities with unique programming opportunities, such grant writing is often essential, because the funding for programming is often nonexistent, or minimal. As librarians work to make grant writing a priority at their institutions, they must be mindful of the importance of building relationships with the university administration, various colleges and departments within the university, individual faculty members, staff, students, and members of the surrounding community. In an era of falling enrollment, budget cuts and pressure from administration to “prove value,” grant writing can also be a great marketing/promotional tool. Furthermore, programming grants can aid in student recruitment and retention, by bringing in not only the university community, but the general community served by the university as well, which can provide a university with greater exposure. There is also the opportunity to collaborate with businesses in the community
On the structure of the scalar mesons and
We investigate the structure of the scalar mesons and
within realistic meson-exchange models of the and
interactions. Starting from a modified version of the J\"ulich model for
scattering we perform an analysis of the pole structure of the
resulting scattering amplitude and find, in contrast to existing models, a
somewhat large mass for the ( MeV,
MeV). It is shown that our model provides a description of
data comparable in quality with those of
alternative models. Furthermore, the formalism developed for the
system is consistently extended to the interaction leading to a
description of the as a dynamically generated threshold effect
(which is therefore neither a conventional state nor a
bound state). Exploring the corresponding pole position the
is found to be rather broad ( MeV,
MeV). The experimentally observed smaller width results from the influence of
the nearby threshold on this pole.Comment: 25 pages, 15 Postscript figure
A Chandra Study of the Effects of a Major Merger on the Structure of Abell 2319
We present an analysis of a Chandra observation of the massive, nearby galaxy
cluster Abell 2319. A sharp surface brightness discontinuity--suggested by
previous, lower angular resolution X-ray imaging--is clearly visible in the
ACIS image. This roughly 300kpc feature suggests that a major merger is taking
place with a significant velocity component perpendicular to the line of sight.
The cluster emission-weighted mean temperature is 11.8+/-0.6kev, somewhat
higher than previous temperature measurements. The Chandra temperature map of
A2319 reveals substructure resembling that anticipated based on hydrodynamic
simulations of cluster mergers. The merger feature shows a pressure change
across the surface brightness discontinuity by a factor of <=2.5. The higher
density side of the front has a lower temperature, suggesting the presence of a
cold front similar to those in many other merging clusters. The velocity of the
front is roughly sonic.
We compare bulk properties of the ICM and galaxies in A2319 to the same
properties in a large sample of clusters as a way of gauging the effects of the
major merger. Interestingly, by comparing A2319 to a sample of 44 clusters
studied with the ROSAT PSPC we find that the X-ray luminosity, isophotal size,
and ICM mass are consistent with the expected values for a cluster of its
temperature; in addition, the K-band galaxy light is consistent with the
light--temperature scaling relation derived from a sample of about 100 clusters
studied with 2MASS. Together, these results indicate either that the merger in
A2319 has not been effective at altering the bulk properties of the cluster, or
that there are large but correlated displacements in these quantities.Comment: 11 pages, 8 figures, ApJ Submitte
Comparing accessibility and connectivity metrics derived from dedicated pedestrian networks and street networks in the context of Asian cities
Studies that compare accessibility and connectivity metrics derived from pedestrian and street networks have been conducted in urban environments outside of Asia. This creates uncertainty concerning the performance of measures calculated on pedestrian networks globally. The purpose of this research is to: (1) develop a dedicated pedestrian network approach suitable for Asian cities; and (2) further develop understanding of pedestrian accessibility and connectivity by including centrality metrics rarely applied to dedicated pedestrian networks before comparing results across network representations. In total, eight networks were created --one dedicated pedestrian and street network each centred on metro stations in Bangkok, Manila, Osaka, and Taipei chosen to represent different urban typologies. Results indicate substantial differences between values calculated on both networks. Measures that have no distance component are particularly susceptible to how the pedestrian network is represented, while distance-based and centrality measures are less affected and more stable across urban forms
Phylogenetic relationships of the Wolbachia of nematodes and arthropods
Wolbachia are well known as bacterial symbionts of arthropods, where they are reproductive parasites, but have also been described from nematode hosts, where the symbiotic interaction has features of mutualism. The majority of arthropod Wolbachia belong to clades A and B, while nematode Wolbachia mostly belong to clades C and D, but these relationships have been based on analysis of a small number of genes. To investigate the evolution and relationships of Wolbachia symbionts we have sequenced over 70 kb of the genome of wOvo, a Wolbachia from the human-parasitic nematode Onchocerca volvulus, and compared the genes identified to orthologues in other sequenced Wolbachia genomes. In comparisons of conserved local synteny, we find that wBm, from the nematode Brugia malayi, and wMel, from Drosophila melanogaster, are more similar to each other than either is to wOvo. Phylogenetic analysis of the protein-coding and ribosomal RNA genes on the sequenced fragments supports reciprocal monophyly of nematode and arthropod Wolbachia. The nematode Wolbachia did not arise from within the A clade of arthropod Wolbachia, and the root of the Wolbachia clade lies between the nematode and arthropod symbionts. Using the wOvo sequence, we identified a lateral transfer event whereby segments of the Wolbachia genome were inserted into the Onchocerca nuclear genome. This event predated the separation of the human parasite O. volvulus from its cattle-parasitic sister species, O. ochengi. The long association between filarial nematodes and Wolbachia symbionts may permit more frequent genetic exchange between their genomes
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