2,682 research outputs found
Investigation of Genetic Structure between Deep and Shallow Populations of the Southern Rock Lobster, Jasus edwardsii in Tasmania, Australia
The southern rock lobster, Jasus edwardsii, shows clear phenotypic differences between shallow water (red
coloured) and deeper water (pale coloured) individuals. Translocations of individuals from deeper water to shallower
waters are currently being trialled as a management strategy to facilitate a phenotypic change from lower value pale
colouration, common in deeper waters, to the higher value red colouration found in shallow waters. Although
panmixia across the J. edwardsii range has been long assumed, it is critical to assess the genetic variability of the
species to ensure that the level of population connectivity is appropriately understood and translocations do not have
unintended consequences. Eight microsatellite loci were used to investigate genetic differentiation between six sites
(three shallow, three deep) across southern Tasmania, Australia, and one from New Zealand. Based on analyses the
assumption of panmixia was rejected, revealing small levels of genetic differentiation across southern Tasmania,
significant levels of differentiation between Tasmania and New Zealand, and high levels of asymmetric gene flow in
an easterly direction from Tasmania into New Zealand. These results suggest that translocation among Tasmanian
populations are not likely to be problematic, however, a re-consideration of panmictic stock structure for this species
is necessary
Anomalous microwave emission from spinning nanodiamonds around stars
Several interstellar environments produce 'anomalous microwave emission'
(AME), with brightness peaks at tens-of-gigahertz frequencies. The
emission's origins are uncertain -- rapidly spinning nanoparticles could
emit electric-dipole radiation, but the polycyclic aromatic hydrocarbons
that have been proposed as the carrier are now found not to correlate
with Galactic AME signals. The difficulty is in identifying co-spatial
sources over long lines of sight. Here we identify AME in three
proto-planetary discs. These are the only known systems that host
hydrogenated nanodiamonds, in contrast to the very common detection of
polycyclic aromatic hydrocarbons. Using spectroscopy, the nanodiamonds
are located close to the host stars, at physically well-constrained
temperatures. Developing disc models, we reproduce the emission with
diamonds 0.75--1.1 nm in radius, holding <= 1-2% of the carbon budget.
Ratios of microwave emission to stellar luminosity are approximately
constant, allowing nanodiamonds to be ubiquitous but emitting below
detection thresholds in many star systems. This result is compatible
with the findings with similar-sized diamonds found within Solar System
meteorites. As nanodiamond spectral absorption is seen in interstellar
sightlines, these particles are also a candidate for generating
galaxy-scale AME
Agriculture and the promotion of insect pests: rice cultivation in river floodplains and malaria vectors in The Gambia
BACKGROUND: Anthropogenic modification of natural habitats can create conditions in which pest species associated with humans can thrive. In order to mitigate for these changes, it is necessary to determine which aspects of human management are associated with the promotion of those pests. Anopheles gambiae, the main Africa malaria vector, often breeds in rice fields. Here the impact of the ancient practice of 'swamp rice' cultivation, on the floodplains of the Gambia River, on the production of anopheline mosquitoes was investigated. METHODS: Routine surveys were carried out along 500 m transects crossing rice fields from the landward edge of the floodplains to the river during the 2006 rainy season. Aquatic invertebrates were sampled using area samplers and emergence traps and fish sampled using nets. Semi-field experiments were used to investigate whether nutrients used for swamp rice cultivation affected mosquito larval abundance. RESULTS: At the beginning of the rainy season rice is grown on the landward edge of the floodplain; the first area to flood with fresh water and one rich in cattle dung. Later, rice plants are transplanted close to the river, the last area to dry out on the floodplain. Nearly all larval and adult stages of malaria vectors were collected 0-100 m from the landward edge of the floodplains, where immature rice plants were grown. These paddies contained stagnant freshwater with high quantities of cattle faeces. Semi-field studies demonstrated that cattle faeces nearly doubled the number of anopheline larvae compared with untreated water. CONCLUSION: Swamp rice cultivation creates ideal breeding sites for malaria vectors. However, only those close to the landward edge harboured vectors. These sites were productive since they were large areas of standing freshwater, rich in nutrients, protected from fish, and situated close to human habitation, where egg-laying mosquitoes from the villages had short distances to fly. The traditional practice of 'swamp rice' cultivation uses different bodies of water on the floodplains to cultivate rice during the rainy season. A consequence of this cultivation is the provizion of ideal conditions for malaria vectors to thrive. As the demand for locally-produced rice grows, increased rice farming will generate great numbers of vectors; emphasizing the need to protect local communities against malaria
The promotion of local wellbeing: A primer for policymakers
There is growing interest among policymakers in the promotion of wellbeing as an
objective of public policy. In particular, local authorities have been given powers to
undertake action to promote wellbeing in their area. Recent advances in the academic
literature on wellbeing are giving rise to an increasingly detailed picture of the factors
that determine people’s subjective wellbeing (how they think and feel about their lives).
However, the concept of subjective wellbeing is poorly understood within local
government and much of the evidence base is extremely recent. I therefore review the
literature on the definition, measurement, and determinants of wellbeing, and discuss
some of its implications for local public policy
Newborn screening for medium chain acyl-CoA dehydrogenase deficiency in England: prevalence, predictive value and test validity based on 1.5 million screened babies
Medium chain acyl-CoA dehydrogenase deficiency (MCADD) is a rare, life-threatening condition. Early diagnosis by screening asymptomatic newborns may improve outcome, but the benefit to newborns identified with variants not encountered clinically is uncertain
An inhomogeneous toy-model of the quantum gravity with explicitly evolvable observables
An inhomogeneous (1+1)-dimensional model of the quantum gravity is
considered. It is found, that this model corresponds to a string propagating
against some curved background space. The quantization scheme including the
Wheeler-DeWitt equation and the "particle on a sphere" type of the gauge
condition is suggested. In the quantization scheme considered, the "problem of
time" is solved by building of the quasi-Heisenberg operators acting in a space
of solutions of the Wheeler-DeWitt equation and the normalization of the wave
function corresponds to the Klein-Gordon type. To analyze the physical
consequences of the scheme, a (1+1)-dimensional background space is considered
for which a classical solution is found and quantized. The obtained estimations
show the way to solution of the cosmological constant problem, which consists
in compensation of the zero-point oscillations of the matter fields by the
quantum oscillations of the scale factor. Along with such a compensation, a
slow global evolution of a background corresponding to an universe expansion
exists.Comment: 18 page
Quantum theory of massless (p,0)-forms
We describe the quantum theory of massless (p,0)-forms that satisfy a
suitable holomorphic generalization of the free Maxwell equations on Kaehler
spaces. These equations arise by first-quantizing a spinning particle with a
U(1)-extended local supersymmetry on the worldline. Dirac quantization of the
spinning particle produces a physical Hilbert space made up of (p,0)-forms that
satisfy holomorphic Maxwell equations coupled to the background Kaehler
geometry, containing in particular a charge that measures the amount of
coupling to the U(1) part of the U(d) holonomy group of the d-dimensional
Kaehler space. The relevant differential operators appearing in these equations
are a twisted exterior holomorphic derivative and its hermitian conjugate
(twisted Dolbeault operators with charge q). The particle model is used to
obtain a worldline representation of the one-loop effective action of the
(p,0)-forms. This representation allows to compute the first few heat kernel
coefficients contained in the local expansion of the effective action and to
derive duality relations between (p,0) and (d-p-2,0)-forms that include a
topological mismatch appearing at one-loop.Comment: 32 pages, 3 figure
Mammography screening: views from women and primary care physicians in Crete
Background: Breast cancer is the most commonly diagnosed cancer among women and a leading cause of death from cancer in women in Europe. Although breast cancer incidence is on the rise worldwide, breast cancer mortality over the past 25 years has been stable or decreasing in some countries and a fall in breast cancer mortality rates in most European countries in the 1990s was reported by several studies, in contrast, in Greece have not reported these favourable trends. In Greece, the age-standardised incidence and mortality rate for breast cancer per 100.000 in 2006 was 81,8 and 21,7 and although it is lower than most other countries in Europe, the fall in breast cancer mortality that observed has not been as great as in other European countries. There is no national strategy for screening in this country. This study reports on the use of mammography among middleaged women in rural Crete and investigates barriers to mammography screening encountered by women and their primary care physicians.
Methods: Design: Semi-structured individual interviews. Setting and participants: Thirty women between 45–65
years of age, with a mean age of 54,6 years, and standard deviation 6,8 from rural areas of Crete and 28 qualified
primary care physicians, with a mean age of 44,7 years and standard deviation 7,0 serving this rural population.
Main outcome measure: Qualitative thematic analysis.
Results: Most women identified several reasons for not using mammography. These included poor knowledge
of the benefits and indications for mammography screening, fear of pain during the procedure, fear of a serious
diagnosis, embarrassment, stress while anticipating the results, cost and lack of physician recommendation.
Physicians identified difficulties in scheduling an appointment as one reason women did not use mammography
and both women and physicians identified distance from the screening site, transportation problems and the
absence of symptoms as reasons for non-use.
Conclusion: Women are inhibited from participating in mammography screening in rural Crete. The provision
of more accessible screening services may improve this. However physician recommendation is important in
overcoming women's inhibitions. Primary care physicians serving rural areas need to be aware of barriers
preventing women from attending mammography screening and provide women with information and advice in a sensitive way so women can make informed decisions regarding breast caner screening
- …