7,001 research outputs found
N-SAP and G-SAP neutron and gamma ray albedo model scatter shield analysis program
Computer program calculates neutron or gamma ray first order scattering from a plane or cylindrical surface to a detector point. The SAP Codes, G-SAP and N-SAP, constitute a multiple scatter albedo model shield analysis
Neutrino masses or new interactions
Recent proposals to study the mass of the "electron" neutrino at a
sensitivity of 0.3 eV can be used to place limits on the right handed and
scalar charged currents at a level which improves on the present experimental
limits. Indeed the neglect of the possibility of such interactions can lead to
the inference of an incorrect value for the mass, as we illustrate.Comment: 12 pages and 3 figures. Contributed to the XX International Symposium
on Lepton and Photon Interactions at High Energies, Rome, July 2001, and to
the International Europhysics Conference on High Energy Physics, Budapest,
July 2001. Preprint numbers added, misprints correcte
Neutrino clustering and the Z-burst model
The possibility that the observed Ultra High Energy Cosmic Rays are generated
by high energy neutrinos creating "Z-bursts" in resonant interactions with the
background neutrinos has been proposed, but there are difficulties in
generating enough events with reasonable incident neutrino fluxes.
We point out that this difficulty is overcome if the background neutrinos
have coalesced into "neutrino clouds" --- a possibility previously suggested by
some of us in another context. The limitations that this mechanism for the
generation of UHECRs places on the high energy neutrino flux, on the masses of
the background neutrinos and the characteristics of the neutrino clouds are
spelled out.Comment: 13 pages and 3 figures. Contributed to the XX International Symposium
on Lepton and Photon Interactions at High Energies, Rome, July 2001, and to
the International Europhysics Conference on High Energy Physics, Budapest,
July 2001. Preprint numbers added, misprints correcte
Gas of self-avoiding loops on the brickwork lattice
An exact calculation of the phase diagram for a loop gas model on the
brickwork lattice is presented. The model includes a bending energy. In the
dense limit, where all the lattice sites are occupied, a phase transition
occuring at an asymmetric Lifshitz tricritical point is observed as the
temperature associated with the bending energy is varied. Various critical
exponents are calculated. At lower densities, two lines of transitions (in the
Ising universality class) are observed, terminated by a tricritical point,
where there is a change in the modulation of the correlation function. To each
tricritical point an associated disorder line is found.Comment: 19 pages, 6 figures. to appear in J. Phys. A : Math. & Ge
A mixed methods study investigating sources of fertility and reproductive health information in the UK
OBJECTIVES: This study aimed to assess the different sources used by individuals when seeking fertility information in order to understand what's working, what isn't, and opportunities for improvement. METHODS: A mixed-method study was conducted via UK-wide cross-sectional survey and semi-structured interviews. 1082 survey-participants were recruited nationwide via online-newspaper and social-media adverts. Of those who agreed to follow-up interview, 35 were purposively sampled to reflect the diversity of gender, age-range, ethnicity and education. Tableau software was used for surveys and NVIVO for interviews. Interview data was transcribed and analysed via thematic framework analysis. RESULTS: Sources of information identified included: school-education; healthcare-professionals; internet, social-media, smartphone-apps, online-forums and blogs; family, friends, and communities; books, magazines, newspapers; fertility-products; workplace, communities and sexual-health clinics/centres, charities, and third-party organisations. Participants reported varying levels of access, reliability, and trust, in relation to these sources. Interview themes around veracity showed that healthcare-professionals were highly trusted but not easily accessible. The internet was very popular due to accessibility and perceived anonymity but untrusted, and "the plethora of information can be overwhelming." There were recurring themes around discomfort. A respondent recalled that her first discussion of sex with her mother was on her wedding night stating, "…Mum, I'm 28! And you're just discussing this with me now?" CONCLUSIONS: School education remains a consistent but sometimes inadequate source of fertility information. In addition to online-platforms and products based on robust scientific evidence, opportunities for improvement include using underexploited sources, such as workplace and community settings, with training for providers
Exploring fertility knowledge amongst healthcare professional and lay population groups in the UK: a mixed methods study.
As the average age of first-time parents continues to rise, there has been a concerted effort by educators, policy makers and several reproductive health groups to improve fertility awareness. This study explored fertility knowledge of lay men and women and healthcare professionals (HCPs) using the same test instrument, providing a new and unique perspective compared with previous studies. Results were obtained from 1082 survey respondents: 347 HCPs, 319 men and 413 women, 105 of whom were trying to conceive (TTC). A total of 35 interviewees were purposively sampled to include 9 HCPs, 13 men and 13 women from the reproductive age range and of varying ethnic and educational backgrounds. Interview data were transcribed and analysed using the framework method. The proportion of HCPs correctly answering the survey knowledge questions was 47.1 (95% CIÂ = 41.7%, 52.5%) compared to 44.4% for women (95% CIÂ = 38.9%, 50.1%); 49.9% (95% CIÂ = 39.0, 59.9%) for women TTC; and 32.5% (95% CIÂ = 27.1%, 37.9%) for men. HCPs were ranked as the most trusted source for seeking fertility information. Overall HCPs did not demonstrate better fertility knowledge than lay participants, with inconsistencies regarding where responsibility lies for providing the right information to patients. HCPs need to improve their knowledge about fertility to help improve patient's fertility awareness
Epoch Dependent Dark Energy
We present a model in which the equation of state parameter w approaches -1
near a particular value of z, and has significant negative values in a
restricted range of z. For example, one can have w ~ -1 near z = 1, and w >
-0.2 from z = 0 to z = 0.3, and for z > 9. The ingredients of the model are
neutral fermions (which may be neutrinos, neutralinos, etc) which are very
weakly coupled to a light scalar field. This model emphasises the importance of
the proposed studies of the properties of dark energy into the region z > 1.Comment: 7pp., 2 figs. Invited talk at the 5th Int'l. Wkshp. on the Dark Side
of the Universe, 1-5 June 2009 Melbourne, DSU09; to appear in the proceeding
Brood patch and sex-ratio observations indicate breeding provenance and timing in New Zealand storm petrel (Fregetta maoriana)
We used measurements of brood patch and moult status to estimate the breeding phenology of New Zealand Storm-Petrel, using birds caught at sea within the Hauraki Gulf Marine Park near Auckland, New Zealand. Birds caught October–January had completely downy brood patches, whereas birds caught February–April had bare brood patches with an observed male bias in the February sex-ratio, consistent with a female pre-laying exodus typical of petrels and with the existence of an unknown colony in the region. No birds captured exhibited primary moult, which is known to occur in storm-petrels during their non-breeding season. Our data support the conclusion that the New Zealand storm-petrel breeds during January–June in northern New Zealand and that field surveys for the species on offshore islands in this region during this period are warrante
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