8,203 research outputs found
Possibility of "magic" co-trapping of two atomic species in optical lattices
Much effort has been devoted to removing differential Stark shifts for atoms
trapped in specially tailored "magic" optical lattices, but thus far work has
focused on a single trapped atomic species. In this work, we extend these ideas
to include two atomic species sharing the same optical lattice. We show
qualitatively that, in particular, scalar J = 0 divalent atoms paired with
non-scalar state atoms have the necessary characteristics to achieve such Stark
shift cancellation. We then present numerical results on "magic" trapping
conditions for 27Al paired with 87Sr, as well as several other divalent atoms.Comment: 5 pages, 2 figures, 1 tabl
Geographical variation in certification rates of blindness and sight impairment in England, 2008-2009
To examine and interpret the variation in the incidence of blindness and sight impairment in England by PCT, as reported by the Certificate of Vision Impairment (CVI).
Design:
Analysis of national certification data.
Setting:
All Primary Care Trusts, England.
Participants:
23â
773 CVI certifications issued from 2008 to 2009.
Main Outcome measures:
Crude and Age standardised rates of CVI data for blindness and sight loss by PCT.
Methods:
The crude and age standardised CVI rates per 100â
000 were calculated with Spearman's rank correlation used to assess whether there was any evidence of association between CVI rates with Index of Multiple Deprivation (IMD) and the Programme Spend for Vision.
Results:
There was high-level variation, almost 11-fold (coefficient of variation 38%) in standardised CVI blindness and sight impairment annual certification rates across PCTs. The mean rate was 43.7 and the SD 16.7. We found little evidence of an association between the rate of blindness and sight impairment with either the IMD or Programme Spend on Vision.
Conclusions:
The wide geographical variation we found raises questions about the quality of the data and whether there is genuine unmet need for prevention of sight loss. It is a concern for public health practitioners who will be interpreting these data locally and nationally as the CVI data will form the basis of the public health indicator âpreventable sight lossâ. Poor-quality data and inadequate interpretation will only create confusion if not addressed adequately from the outset. There is an urgent need to address the shortcomings of the current data collection system and to educate all public health practitioners
The Importance of Forage Legume Epigenetics in the Anthropocene
As climates change and economic as well as ecological pressures to produce more ruminant product on less land in the Anthropocene increase, the importance of using cutting-edge methods for forage legume improvement grows. The immediate return rate and turnaround on investment is likely greater for multi-species incorporation into grasslands but focusing on intraspecific variability and diversity could also contribute. The role of forage legumes in cultivated pasture and rangeland biodiversity as well as stability depends on genetics as well as management. Their epigenetics, however, may become increasingly important as climatic extremes and ecological pressures grow due to human-induced factors. Unfortunately, in many cases, forage legume epigenetics remain a black box. As we deal with the need for increasingly diverse forage legume species, should we be planning for this future in which genetic selection and improvement must also factor in epigenetic impacts in diverse edaphoclimatic and management systems
Characterization of Forage Selected by Cattle on Communal Range in Manhiça, Mozambique
Forage selection by 10 cattle herds was observed monthly over 2 years on a communal rangeland. Plants grazed were hand-plucked as representative of both species and plant portions being cropped by cattle. Herds were led to green pasture year-round. Nutrient concentration of species and plant portions selected by cattle indicated adequate crude protein and calcium but phosphorus deficiency during the dry season. Well-drained escarpments and uplands were more important during the rains while upland depressions and the Nkomati valley were essential for adequate forage intake during the dry seasons
Billy Elliot The Musical: visual representations of working-class masculinity and the all-singing, all-dancing bo[d]y
According to Cynthia Weber, â[d]ance is commonly thought of as liberating, transformative, empowering, transgressive, and even as dangerousâ. Yet ballet as a masculine activity still remains a suspect phenomenon. This paper will challenge this claim in relation to Billy Elliot the Musical and its critical reception. The transformation of the visual representation of the human body on stage (from
an ephemeral existence to a timeless work of art) will be discussed and analysed vis-a-vis the text and sub-texts of Stephen Daldryâs direction and Peter Darlingâs
choreography. The dynamics of working-class masculinity will be contextualised within the framework of the family, the older female, the community, the self and
the act of dancing itself
Bootstrap Technique to Study Correlation Between Neutron Skin Thickness and the Slope of Symmetry Energy in Atomic Nuclei
We examine the proposed correlation between the neutron skin thickness and the slope of the symmetry energy for two doubly-magic nuclei (Sn-100 and Sn-132) and find that a statistically significant correlation appears to exist for Sn-132 whilst no such correlation appears to exist for Sn-100. Additionally, we present a new statistical tool based on random sampling to assess the confidence interval of Pearson's and Spearman's correlation coefficients in order to examine the aforementioned correlation. These estimators are then used to quantify the statistical correlations among the neutron skin thickness of atomic nuclei and the slope of the symmetry energy in the infinite nuclear medium.Peer reviewe
Ecosystem uptake and transfer of Sellafield-derived radiocarbon (14C). Part 1. The Irish Sea
Ecosystem uptake and transfer processes of Sellafield-derived radiocarbon (14C) within the Irish Sea were examined. Highly variable activities in sediment, seawater and biota indicate complex 14C dispersal and uptake dynamics. All east basin biota exhibited 14C enrichments above ambient background while most west basin biota had 14C activities close to background, although four organisms including two slow-moving species were significantly enriched. The western Irish Sea gyre is a suggested pathway for transfer of 14C to the west basin and retention therein. Despite ongoing Sellafield 14C discharges, organic sediments near Sellafield were significantly less enriched than associated benthic organisms. Rapid scavenging of labile, 14C-enriched organic material by organisms and mixing to depth of 14C-enriched detritus arriving at the sediment/water interface are proposed mechanisms to explain this. All commercially important fish, crustaceans and molluscs showed 14C enrichments above background; however, the radiation dose from their consumption is extremely low and radiologically insignificant
Accumulation of Sellafield-derived radiocarbon (14C) in Irish Sea and West of Scotland intertidal shells and sediments
The nuclear energy industry produces radioactive waste at various stages of the fuel cycle. In
the United Kingdom, spent fuel is reprocessed at the Sellafield facility in Cumbria on the
north west coast of England. Waste generated at the site comprises a wide range of
radionuclides including radiocarbon (14C) which is disposed of in various forms including
highly soluble inorganic carbon within the low level liquid radioactive effluent, via pipelines
into the Irish Sea. This 14C is rapidly incorporated into the dissolved inorganic carbon (DIC)
reservoir and marine calcifying organisms, e.g. molluscs, readily utilise DIC for shell
formation. This study investigated a number of sites located in Irish Sea and West of Scotland
intertidal zones. Results indicate 14C enrichment above ambient background levels in shell
material at least as far as Port Appin, 265 km north of Sellafield. Of the commonly found
species (blue mussel (Mytilus edulis), common cockle (Cerastoderma edule) and common
periwinkle (Littorina littorea)), mussels were found to be the most highly enriched in 14C due
to the surface environment they inhabit and their feeding behaviour. Whole mussel shell
activities appear to have been decreasing in response to reduced discharge activities since the
early 2000s but in contrast, there is evidence of continuing enrichment of the carbonate
sediment component due to in-situ shell erosion, as well as indications of particle transport of
fine 14C-enriched material close to Sellafield
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