236 research outputs found
Exploring the Time to Intervene with a Reactive Mass Vaccination Campaign in Measles Epidemics.
The current WHO policy during measles outbreaks focuses on case management rather than reactive vaccination campaigns in urban areas of resource-poor countries having low vaccine coverage. Vaccination campaigns may be costly, or not timely enough to impact significantly on morbidity and mortality. We explored the time available for intervention during two recent epidemics. Our analysis suggests that the spread of measles in African urban settings may not be as fast as expected. Examining measles epidemic spread in Kinshasa (DRC), and Niamey (Niger) reveals a progression of smaller epidemics. Intervening with a mass campaign or in areas where cases have not yet been reported could slow the epidemic spread. The results of this preliminary analysis illustrate the importance of revisiting outbreak response plans
Structure properties of Th and Fm fission fragments: mean field analysis with the Gogny force
The constrained Hartree-Fock-Bogoliubov method is used with the Gogny
interaction D1S to calculate potential energy surfaces of fissioning nuclei
Th and Fm up to very large deformations. The
constraints employed are the mass quadrupole and octupole moments. In this
subspace of collective coordinates, many scission configurations are identified
ranging from symmetric to highly asymmetric fragmentations. Corresponding
fragment properties at scission are derived yielding fragment deformations,
deformation energies, energy partitioning, neutron binding energies at
scission, neutron multiplicities, charge polarization and total fragment
kinetic energies.Comment: 15 pages, 23 figures, accepted for publication in Phys. Rev. C (2007
Nuclei with Tetrahedral Symmetry
We discuss a point-group-theory based method of searching for new regions of
nuclear stability. We illustrate the related strategy with realistic
calculations employing the tetrahedral and the octahedral point groups. In
particular, several nuclei in the Rare Earth region appear as excellent
candidates to study the new mechanism.Comment: 18 pages, 4 figures, submitted to International Journal of Modern
Physics
GDR Feeding of the Highly-Deformed Band in 42Ca
The gamma-ray spectra from the decay of the GDR in the compound nucleus
reaction 18O+28Si at bombarding energy of 105 MeV have been measured in an
experiment using the EUROBALL IV and HECTOR arrays. The obtained experimental
GDR strength function is highly fragmented, with a low energy (10 MeV)
component, indicating a presence of a large deformation and Coriolis effects.
In addition, the preferential feeding of the highly-deformed band in 42Ca by
this GDR low energy component is observed.Comment: 6 pages, 2 figures, Proceedings of the Zakopane2004 Symposium, to be
published in Acta Phys. Pol. B36 (2005
Le mouflon de Corse
Synthèse des études disponibles sur le mouflon de Corse en France (Génétique population, répartition, particularités morphologiques, particularités physiologiques, pathologie, utilisation de l'espace, utilisation du temps,
alimentation, vie sociale, comportement reproducteur, relations interspécifiques, dynamique et structure des populations
Evidence for the Jacobi shape transition in hot 46Ti
The gamma-rays from the decay of the GDR in 46Ti compound nucleus formed in
the 18O+28Si reaction at bombarding energy 105 MeV have been measured in an
experiment using a setup consisting of the combined EUROBALL IV, HECTOR and
EUCLIDES arrays. A comparison of the extracted GDR lineshape data with the
predictions of the thermal shape fluctuation model shows evidence for the
Jacobi shape transition in hot 46Ti. In addition to the previously found broad
structure in the GDR lineshape region at 18-27 MeV caused by large
deformations, the presence of a low energy component (around 10 MeV), due to
the Coriolis splitting in prolate well deformed shape, has been identified for
the first time.Comment: 8 pages, 4 figures, proceedings of the COMEX1 conference, June 2003,
Paris; to be published in Nucl. Phys.
Fission description: First steps towards a full resolution of the time-dependent Hill-Wheeler equation
Unacceptably High Mortality Related to Measles Epidemics in Niger, Nigeria, and Chad
BACKGROUND: Despite the comprehensive World Health Organization (WHO)/United Nations Children's Fund (UNICEF) measles mortality–reduction strategy and the Measles Initiative, a partnership of international organizations supporting measles mortality reduction in Africa, certain high-burden countries continue to face recurrent epidemics. To our knowledge, few recent studies have documented measles mortality in sub-Saharan Africa. The objective of our study was to investigate measles mortality in three recent epidemics in Niamey (Niger), N'Djamena (Chad), and Adamawa State (Nigeria). METHODS AND FINDINGS: We conducted three exhaustive household retrospective mortality surveys in one neighbourhood of each of the three affected areas: Boukoki, Niamey, Niger (April 2004, n = 26,795); Moursal, N'Djamena, Chad (June 2005, n = 21,812); and Dong District, Adamawa State, Nigeria (April 2005, n = 16,249), where n is the total surveyed population in each of the respective areas. Study populations included all persons resident for at least 2 wk prior to the study, a duration encompassing the measles incubation period. Heads of households provided information on measles cases, clinical outcomes up to 30 d after rash onset, and health-seeking behaviour during the epidemic. Measles cases and deaths were ascertained using standard WHO surveillance-case definitions. Our main outcome measures were measles attack rates (ARs) and case fatality ratios (CFRs) by age group, and descriptions of measles complications and health-seeking behaviour. Measles ARs were the highest in children under 5 y old (under 5 y): 17.1% in Boukoki, 17.2% in Moursal, and 24.3% in Dong District. CFRs in under 5-y-olds were 4.6%, 4.0%, and 10.8% in Boukoki, Moursal, and Dong District, respectively. In all sites, more than half of measles cases in children aged under 5 y experienced acute respiratory infection and/or diarrhoea in the 30 d following rash onset. Of measles cases, it was reported that 85.7% (979/1,142) of patients visited a health-care facility within 30 d after rash onset in Boukoki, 73.5% (519/706) in Moursal, and 52.8% (603/1,142) in Dong District. CONCLUSIONS: Children in these countries still face unacceptably high mortality from a completely preventable disease. While the successes of measles mortality–reduction strategies and progress observed in measles control in other countries of the region are laudable and evident, they should not overshadow the need for intensive efforts in countries that have just begun implementation of the WHO/UNICEF comprehensive strategy
- …