8,567 research outputs found
A "nu" look at gravitational waves: The black hole birth rate from neutrinos combined with the merger rate from LIGO
We make projections for measuring the black hole birth rate from the diffuse
supernova neutrino background (DSNB) by future neutrino experiments, and
constrain the black hole merger fraction , when combined with
information on the black hole merger rate from gravitational wave experiments
such as LIGO. The DSNB originates from neutrinos emitted by all the supernovae
in the Universe, and is expected to be made up of two components: neutrinos
from neutron-star-forming supernovae, and a sub-dominant component at higher
energies from black-hole-forming "unnovae". We perform a Markov Chain Monte
Carlo analysis of simulated data of the DSNB in an experiment similar to
Hyper-Kamiokande, focusing on this second component. Since all knowledge of the
neutrino emission from unnovae comes from simulations of collapsing stars, we
choose two sets of priors: one where the unnovae are well-understood and one
where their neutrino emission is poorly known. By combining the black hole
birth rate from the DSNB with projected measurements of the black hole merger
rate from LIGO, we show that the fraction of black holes which lead to binary
mergers observed today could be constrained to be within the range
at confidence,
after ten years of running an experiment like Hyper-Kamiokande.Comment: 19 pages, 6 figures. v3: Matches version accepted to JCA
Extremely low-frequency spectroscopy in low-field nuclear magnetic resonance
We demonstrate a new phenomenon in nuclear magnetic resonance spectroscopy, in which nuclear spin transitions are induced by radio frequency irradiation at extremely low frequencies (of the order of a few Hz). Slow Rabi oscillations are observed between spin states of different exchange symmetry. These “forbidden” transitions are rendered weakly allowed by differential electronic shielding effects on the radio frequency field. We generate coherence between the singlet and triplet states of 15N-labeled nitrous oxide in solution, and estimate the scalar coupling between the two 15N nuclei with a precision of a few mHz
Symmetry-based pulse sequences in solid-state NMR and applications to biological systems
We present some applications of solid-state nuclear magnetic resonance to model compounds and biological systems. We highlight a class of pulse sequences that are designed based on symmetry properties of the internal spin interactions. Examples are given showing resonance assignments, determination of internuclear distances, and torsion angle determinations in representative model systems as well as true biological systems
Effect of culture on acceptance of telemedicine in Middle Eastern countries: Case study of Jordan and Syria
© Mary Ann Liebert, INC.We investigated issues that affect the use and adoption of telemedicine in Middle Eastern countries, taking the Hashemite Kingdom of Jordan and the Syrian Arab Republic as case studies. Our study is based on interviews with key stakeholders (including doctors, technicians, engineers, and decision makers) and questionnaires administered to key stakeholders (including patients), ensuring opinion was gained from people from a full range of backgrounds and roles in the healthcare system. We found doctor and patient resistance was a major issue preventing the adoption of telemedicine in both countries, followed by poor infrastructure, lack of funding, and lack of information technology training. Our research identifies that culture is a greater issue than technical matters for the adoption of telemedicine in Middle Eastern countries. Based on our preliminary results we developed a guideline framework for each country that might be applied to telemedicine projects at the pre-implementation phase. The proposed guideline framework was validated through a return visit to the stakeholders and seeking further opinion
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