418 research outputs found
Calculating error bars for neutrino mixing parameters
One goal of contemporary particle physics is to determine the mixing angles
and mass-squared differences that constitute the phenomenological constants
that describe neutrino oscillations. Of great interest are not only the best
fit values of these constants but also their errors. Some of the neutrino
oscillation data is statistically poor and cannot be treated by normal
(Gaussian) statistics. To extract confidence intervals when the statistics are
not normal, one should not utilize the value for chisquare versus confidence
level taken from normal statistics. Instead, we propose that one should use the
normalized likelihood function as a probability distribution; the relationship
between the correct chisquare and a given confidence level can be computed by
integrating over the likelihood function. This allows for a definition of
confidence level independent of the functional form of the !2 function; it is
particularly useful for cases in which the minimum of the !2 function is near a
boundary. We present two pedagogic examples and find that the proposed method
yields confidence intervals that can differ significantly from those obtained
by using the value of chisquare from normal statistics. For example, we find
that for the first data release of the T2K experiment the probability that
chisquare is not zero, as defined by the maximum confidence level at which the
value of zero is not allowed, is 92%. Using the value of chisquare at zero and
assigning a confidence level from normal statistics, a common practice, gives
the over estimation of 99.5%.Comment: 9 pages, 6 figure
Neutrino Oscillations: Hierarchy Question
The only experimentally observed phenomenon that lies outside the standard
model of the electroweak interaction is neutrino oscillations. A way to try to
unify the extensive neutrino oscillation data is to add a phenomenological mass
term to the Lagrangian that is not diagonal in the flavor basis. The goal is
then to understand the world's data in terms of the parameters of the mixing
matrix and the differences between the squares of the masses of the neutrinos.
An outstanding question is what is the correct ordering of the masses, the
hierarchy question. We point out a broken symmetry relevant to this question,
the symmetry of the simultaneous interchange of hierarchy and the sign of
. We first present the results of an analysis of data that well
determine the phenomenological parameters but are not sensitive to the
hierarchy. We find , and
eV, results consistent with others. We then include data that are sensitive
to the hierarchy and the sign of . We find, unlike others, four
isolated minimum in the -space as predicted by the symmetry. Now that
Daya Bay and RENO have determined to be surprisingly large, the
Super-K atmospheric data produce meaningful symmetry breaking such that the
inverse hierarchy is preferred at the 97.2 % level.Comment: to appear in Proceedings of the 5th International Conference on
Fission and Neutron Rich Nuclei (ICFN5), (Sanibel Island, Florina, Nov. 4-10,
2012).10 pages, 8 figure
Report of the Scientific Council Meeting 01 -15 June 2017
Council met at the Sobey Building, Saint Mary’s University, Halifax, NS, Canada, during 01 – 15 June 2017, to consider the various matters in its Agenda. Representatives attended from Canada, Denmark (in
respect of Faroe Islands and Greenland), the European Union (France, Germany (via WebEx), Portugal, Spain, the United Kingdom and the European Commission), Japan, the Russian Federation and the United States of
America. Observers from the Ecology Action Centre and Dalhousie University were also present. The Executive Secretary, Scientific Council Coordinator and other members of the Secretariat were in attendance.
The Executive Committee met prior to the opening session of the Council to discuss the provisional agenda and plan of work.
The Council was called to order at 1000 hours on 01 June 2017. The provisional agenda was adopted with modification. The Scientific Council Coordinator was appointed the rapporteur.
The Council was informed that the meeting was quorate and authorization had been received by the Executive Secretary for proxy votes from the European Union, Denmark (in respect of Faroe Islands and Greenland),
Iceland, Japan, Republic of Korea, and Norway. The opening session was adjourned at 1200 hours on 01 June 2017. Several sessions were held throughout the
course of the meeting to deal with specific items on the agenda. The Council considered adopted the STACFEN report on 8 June 2017, and the STACPUB, STACFIS and STACREC reports on 15 June 2017.
The concluding session was called to order at 0830 hours on 15 June 2017. The Council considered and adopted the report the Scientific Council Report of this meeting of 01 -15 June
2017. The Chair received approval to leave the report in draft form for about two weeks to allow for minor editing and proof-reading on the usual strict understanding there would be no substantive changes.
The meeting was adjourned at 1430 hours on 15 June 2017. The Reports of the Standing Committees as adopted by the Council are appended as follows: Appendix I - Report
of the Standing Committee on Fisheries Environment (STACFEN), Appendix II - Report of Standing Committee on Publications (STACPUB), Appendix III - Report of Standing Committee on Research Coordination
(STACREC), and Appendix IV - Report of Standing Committee on Fisheries Science (STACFIS). The Agenda, List of Research (SCR) and Summary (SCS) Documents, and List of Representatives, Advisers and
Experts, are given in Appendix V-VII. The Council’s considerations on the Standing Committee Reports, and other matters addressed by the Council
follow in Sections II-XV
Coral Identification Guide NAFO Area
Accurate reporting of benthic corals is increasingly important for mapping distributions and for
the continued development of sustainable fisheries under the ecosystem approach. This coral identification
guide is intended to help those on-board commercial and research fishing vessels to identify
and record the various species of coral likely to be commonly encountered in fishing trawls. The
guide is clear and simple to use, and will provide names to the majority of these beautiful bottomdwelling
animals. The photographs are typically of caught specimens taken on the deck, as this gives
the best picture of what is actually seen. Sadly, we rarely personally see corals in their natural habitat,
except by looking at films and photos taken by deep underwater cameras
Suppression of Phase Separation in LiFePO4 Nanoparticles During Battery Discharge
Using a novel electrochemical phase-field model, we question the common
belief that LixFePO4 nanoparticles separate into Li-rich and Li-poor phases
during battery discharge. For small currents, spinodal decomposition or
nucleation leads to moving phase boundaries. Above a critical current density
(in the Tafel regime), the spinodal disappears, and particles fill
homogeneously, which may explain the superior rate capability and long cycle
life of nano-LiFePO4 cathodes.Comment: 27 pages, 8 figure
Tracking development assistance for health and for COVID-19 : a review of development assistance, government, out-of-pocket, and other private spending on health for 204 countries and territories, 1990–2050
Background: The rapid spread of COVID-19 renewed the focus on how health systems across the globe are financed, especially during public health emergencies. Development assistance is an important source of health financing in many low-income countries, yet little is known about how much of this funding was disbursed for COVID-19. We aimed to put development assistance for health for COVID-19 in the context of broader trends in global health financing, and to estimate total health spending from 1995 to 2050 and development assistance for COVID-19 in 2020. Methods: We estimated domestic health spending and development assistance for health to generate total health-sector spending estimates for 204 countries and territories. We leveraged data from the WHO Global Health Expenditure Database to produce estimates of domestic health spending. To generate estimates for development assistance for health, we relied on project-level disbursement data from the major international development agencies' online databases and annual financial statements and reports for information on income sources. To adjust our estimates for 2020 to include disbursements related to COVID-19, we extracted project data on commitments and disbursements from a broader set of databases (because not all of the data sources used to estimate the historical series extend to 2020), including the UN Office of Humanitarian Assistance Financial Tracking Service and the International Aid Transparency Initiative. We reported all the historic and future spending estimates in inflation-adjusted 2020 US per capita, purchasing-power parity-adjusted US8·8 trillion (95% uncertainty interval [UI] 8·7–8·8) or 40·4 billion (0·5%, 95% UI 0·5–0·5) was development assistance for health provided to low-income and middle-income countries, which made up 24·6% (UI 24·0–25·1) of total spending in low-income countries. We estimate that 13·7 billion was targeted toward the COVID-19 health response. 1·4 billion was repurposed from existing health projects. 2·4 billion (17·9%) was for supply chain and logistics. Only 1519 (1448–1591) per person in 2050, although spending across countries is expected to remain varied. Interpretation: Global health spending is expected to continue to grow, but remain unequally distributed between countries. We estimate that development organisations substantially increased the amount of development assistance for health provided in 2020. Continued efforts are needed to raise sufficient resources to mitigate the pandemic for the most vulnerable, and to help curtail the pandemic for all. Funding: Bill & Melinda Gates Foundation
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