939 research outputs found
Violations of local realism by two entangled quNits
Results obtained in two recent papers, \cite{Kaszlikowski} and \cite{Durt},
seem to indicate that the nonlocal character of the correlations between the
outcomes of measurements performed on entangled systems separated in space is
not robust in the presence of noise. This is surprising, since entanglement
itself is robust. Here we revisit this problem and argue that the class of
gedanken-experiments considered in \cite{Kaszlikowski} and \cite{Durt} is too
restrictive. By considering a more general class, involving sequences of
measurements, we prove that the nonlocal correlations are in fact robust.Comment: Reference added, 3 pages, accepted for publication in J. Phys. A:
Math. and Genera
The Occurrence Rate of Earth Analog Planets Orbiting Sunlike Stars
Kepler is a space telescope that searches Sun-like stars for planets. Its
major goal is to determine {\eta}_Earth, the fraction of Sunlike stars that
have planets like Earth. When a planet 'transits' or moves in front of a star,
Kepler can measure the concomitant dimming of the starlight. From analysis of
the first four months of those measurements for over 150,000 stars, Kepler's
science team has determined sizes, surface temperatures, orbit sizes and
periods for over a thousand new planet candidates. In this paper, we
characterize the period probability distribution function of the super-Earth
and Neptune planet candidates with periods up to 132 days, and find three
distinct period regimes. For candidates with periods below 3 days the density
increases sharply with increasing period; for periods between 3 and 30 days the
density rises more gradually with increasing period, and for periods longer
than 30 days, the density drops gradually with increasing period. We estimate
that 1% to 3% of stars like the Sun are expected to have Earth analog planets,
based on the Kepler data release of Feb 2011. This estimate of is based on
extrapolation from a fiducial subsample of the Kepler planet candidates that we
chose to be nominally 'complete' (i.e., no missed detections) to the realm of
the Earth-like planets, by means of simple power law models. The accuracy of
the extrapolation will improve as more data from the Kepler mission is folded
in. Accurate knowledge of {\eta}_Earth is essential for the planning of future
missions that will image and take spectra of Earthlike planets. Our result that
Earths are relatively scarce means that a substantial effort will be needed to
identify suitable target stars prior to these future missions.Comment: Accepted for publication in the Astrophysical Journal. 19 pages, 8
figures. Minor text revisions, as requested by the scientific editor.
Included an additional figure. No changes in the scientific result
Linear Collider Capabilities for Supersymmetry in Dark Matter Allowed Regions of the mSUGRA Model
Recent comparisons of minimal supergravity (mSUGRA) model predictions with
WMAP measurements of the neutralino relic density point to preferred regions of
model parameter space. We investigate the reach of linear colliders (LC) with
and 1 TeV for SUSY in the framework of the mSUGRA model. We find
that LCs can cover the entire stau co-annihilation region provided \tan\beta
\alt 30. In the hyperbolic branch/focus point (HB/FP) region of parameter
space, specialized cuts are suggested to increase the reach in this important
``dark matter allowed'' area. In the case of the HB/FP region, the reach of a
LC extends well past the reach of the CERN LHC. We examine a case study in the
HB/FP region, and show that the MSSM parameters and can be
sufficiently well-measured to demonstrate that one would indeed be in the HB/FP
region, where the lightest chargino and neutralino have a substantial higgsino
component.Comment: 29 pages, 15 EPS figures; updated version slightly modified to
conform with published versio
Measuring the Higgs Sector
If we find a light Higgs boson at the LHC, there should be many observable
channels which we can exploit to measure the relevant parameters in the Higgs
sector. We use the SFitter framework to map these measurements on the parameter
space of a general weak-scale effective theory with a light Higgs state of mass
120 GeV. Our analysis benefits from the parameter determination tools and the
error treatment used in new--physics searches, to study individual parameters
and their error bars as well as parameter correlations.Comment: 45 pages, Journal version with comments from refere
Probing the neutrino mass hierarchy with CMB weak lensing
We forecast constraints on cosmological parameters with primary CMB
anisotropy information and weak lensing reconstruction with a future
post-Planck CMB experiment, the Cosmic Origins Explorer (COrE), using
oscillation data on the neutrino mass splittings as prior information. Our MCMC
simulations in flat models with a non-evolving equation-of-state of dark energy
w give typical 68% upper bounds on the total neutrino mass of 0.136 eV and
0.098 eV for the inverted and normal hierarchies respectively, assuming the
total summed mass is close to the minimum allowed by the oscillation data for
the respective hierarchies (0.10 eV and 0.06 eV). Including information from
future baryon acoustic oscillation measurements with the complete BOSS, Type 1a
supernovae distance moduli from WFIRST, and a realistic prior on the Hubble
constant, these upper limits shrink to 0.118 eV and 0.080 eV for the inverted
and normal hierarchies, respectively. Addition of these distance priors also
yields percent-level constraints on w. We find tension between our MCMC results
and the results of a Fisher matrix analysis, most likely due to a strong
geometric degeneracy between the total neutrino mass, the Hubble constant, and
w in the unlensed CMB power spectra. If the minimal-mass, normal hierarchy were
realised in nature, the inverted hierarchy should be disfavoured by the full
data combination at typically greater than the 2-sigma level. For the
minimal-mass inverted hierarchy, we compute the Bayes' factor between the two
hierarchies for various combinations of our forecast datasets, and find that
the future probes considered here should be able to provide `strong' evidence
(odds ratio 12:1) for the inverted hierarchy. Finally, we consider potential
biases of the other cosmological parameters from assuming the wrong hierarchy
and find that all biases on the parameters are below their 1-sigma marginalised
errors.Comment: 16 pages, 13 figures; minor changes to match the published version,
references adde
Practices and values regarding milk consumption among pre-schoolers in Bangkok
Purpose: Thai government agencies and the business sector have been promoting milk consumption. Considering the robust and continual movements by those actors to promote milk consumption among children in Thailand at the national level, this study aims to investigate milk-consumption practices and values towards milk consumption at pre-school, family and individual levels. Methods: This cross-sectional qualitative study employs observation and interview methods, along with the Ecological System Theory as a framework. Data were collected from three kindergartens used by families of varying socio-economic status, and the homes of 18 pre-schoolers, aged 3-5 years old, attending these kindergartens, from October 2013-September 2014. Results: Findings reveal kindergartens implemented daily routines to make children drink milk. Practices at home include (i) overfeeding of milk, (ii) preference for fortified milk and (iii) using sweetness to make children drink milk. These practices were underpinned by values that milk is good for children and good parents feed their children milk. These values, in combination with other macro-level measures such as the government’s milk-promotion campaigns and the milk industry’s marketing, influence the milk-drinking practices of pre-schoolers. Conclusion: The promotion of the benefits of milk prompted children to exceed the recommended milk consumption of 400ml per day. Balanced information on moderation in milk drinking was absent
Improving energy efficiency in private rented housing : what makes landlords act?
The private rented sector in England contains some of the least energy efficient properties in the
country and houses more vulnerable households than any other sector. Occupants endure dangerously
cold homes and fuel poverty but have no direct influence over the energy performance of their homes.
The choices that occupants make regarding energy are constrained by the material characteristics of a
property: something only the landlord can alter. Enduringly poor conditions in the sector indicate that
an initiative that convinces landlords of the benefits of improving energy efficiency remains elusive.
Based on a review of existing research and 30 interviews with landlords, this paper identifies factors
which deter landlords from acting to improve energy efficiency. Factors include lack of knowledge
regarding the consequences of energy inefficiency and possible solutions, the absence of direct financial
incentives (the principal–agent problem), local housing market and cultural factors. It also identifies
a number of motivating factors that may encourage landlords to invest in energy efficiency. It is argued
that policies to tackle energy inefficiency in the sector should take account of these factors in order to
improve effectiveness.
Keywords
Private rented sector, Domestic energy efficiency, Principal–agent, The Green Deal, Private landlords,
Split incentiv
A Cross-Sectional Survey on Knowledge and Perceptions of Health Risks Associated with Arsenic and Mercury Contamination from Artisanal Gold mining in Tanzania.
An estimated 0.5 to 1.5 million informal miners, of whom 30-50% are women, rely on artisanal mining for their livelihood in Tanzania. Mercury, used in the processing gold ore, and arsenic, which is a constituent of some ores, are common occupational exposures that frequently result in widespread environmental contamination. Frequently, the mining activities are conducted haphazardly without regard for environmental, occupational, or community exposure. The primary objective of this study was to assess community risk knowledge and perception of potential mercury and arsenic toxicity and/or exposure from artisanal gold mining in Rwamagasa in northwestern Tanzania. A cross-sectional survey of respondents in five sub-villages in the Rwamagasa Village located in Geita District in northwestern Tanzania near Lake Victoria was conducted. This area has a history of artisanal gold mining and many of the population continue to work as miners. Using a clustered random selection approach for recruitment, a total of 160 individuals over 18 years of age completed a structured interview. The interviews revealed wide variations in knowledge and risk perceptions concerning mercury and arsenic exposure, with 40.6% (n=65) and 89.4% (n=143) not aware of the health effects of mercury and arsenic exposure respectively. Males were significantly more knowledgeable (n=59, 36.9%) than females (n=36, 22.5%) with regard to mercury (x²=3.99, p<0.05). An individual's occupation category was associated with level of knowledge (x²=22.82, p=<0.001). Individuals involved in mining (n=63, 73.2%) were more knowledgeable about the negative health effects of mercury than individuals in other occupations. Of the few individuals (n=17, 10.6%) who knew about arsenic toxicity, the majority (n=10, 58.8%) were miners. The knowledge of individuals living in Rwamagasa, Tanzania, an area with a history of artisanal gold mining, varied widely with regard to the health hazards of mercury and arsenic. In these communities there was limited awareness of the threats to health associated with exposure to mercury and arsenic. This lack of knowledge, combined with minimal environmental monitoring and controlled waste management practices, highlights the need for health education, surveillance, and policy changes
The normalisation of drug supply: The social<i>supply</i>of drugs as the “other side” of the history of normalisation
Aims: Describes how the relative normalisation of recreational drug use in the UK has been productive of, and fused with, the relatively normalised and non-commercial social supply of recreational drugs. Methods: Semi-structured interviews with 60 social suppliers of recreational drugs in two studies (involving a student population n = 30 and general population sample n = 30). Respondents were recruited via purposive snowball sampling and local advertising. Findings: Both samples provided strong evidence of the normalised supply of recreational drugs in micro-sites of friendship and close social networks. Many social suppliers described “drift” into social supply and normalised use was suggested to be productive of supply relationships that both suppliers and consumers regard as something less than “real” dealing in order to reinforce their preconceptions of themselves as relatively non-deviant. Some evidence for a broader acceptance of social supply is also presented. Conclusions: The fairly recent context of relative normalisation of recreational drug use has coalesced with the social supply of recreational drugs in micro-sites of use and exchange whereby a range of “social” supply acts (sometimes even involving large amounts of drugs/money) have become accepted as something closer to gift-giving or friendship exchange dynamics within social networks rather than dealing proper. To some degree, there is increasing sensitivity to this within the criminal justice system
Promoting Physical Activity with Hard-to-Reach Women: An Iterative and Participatory Research Study
Approximately half of all UK women are insufficiently physically active, with the lowest activity rates among ‘Hard-to-Reach’ or unreached women. In this article, Kathryn Brook, Dr Andy Pringle FRSPH, Dr Jackie Hargreaves and Dr Nicky Kime of Leeds Beckett University outline their research into developing methods to assess and meet the needs of ‘Hard-to-Reach’ women in needs-led and person-centred interventions
- …
