9 research outputs found
Systematic Study of High p_T Hadron Spectra in pp, pA and AA Collisions from SPS to RHIC Energies
High- particle spectra in (), and
collisions are calculated within a QCD parton model in which intrinsic
transverse momentum, its broadening due to initial multiple parton scattering,
and jet quenching due to parton energy loss inside a dense medium are included
phenomenologically. The intrinsic and its broadening in and
collisions due to initial multiple parton scattering are found to be very
important at low energies ( GeV). Comparisons with ,
and data with different centrality cuts show that the differential
cross sections of large transverse momentum pion production ( GeV/)
in collisions scale very well with the number of binary nucleon-nucleon
collisions (modulo effects of multiple initial scattering). This indicates that
semi-hard parton scattering is the dominant particle production mechanism
underlying the hadron spectra at moderate GeV/.
However, there is no evidence of jet quenching or parton energy loss. Within
the parton model, one can exclude an effective parton energy loss
GeV/fm and a mean free path fm from the
experimental data of collisions at the SPS energies. Predictions for high
particle spectra in and collisions with and without jet
quenching at the RHIC energy are also given. Uncertainties due to initial
multiple scattering and nuclear shadowing of parton distributions are also
discussed.Comment: 13 pages in RevTex with 14 figures, the final published version (with
some typos corrected
Democratisation via Elections in an African 'Narco State'? - The Case of Guinea-Bissau
Malaria prevention reduces in-hospital mortality among severely ill tuberculosis patients: a three-step intervention in Bissau, Guinea-Bissau.
BACKGROUND: Malaria and Tuberculosis (TB) are important causes of morbidity and mortality in Africa. Malaria prevention reduces mortality among HIV patients, pregnant women and children, but its role in TB patients is not clear. In the TB National Reference Center in Guinea-Bissau, admitted patients are in severe clinical conditions and mortality during the rainy season is high. We performed a three-step malaria prevention program to reduce mortality in TB patients during the rainy season. METHODS: Since 2005 Permethrin treated bed nets were given to every patient. Since 2006 environmental prevention with permethrin derivates was performed both indoor and outdoor during the rainy season. In 2007 cotrimoxazole prophylaxis was added during the rainy season. Care was without charge; health education on malaria prevention was performed weekly. Primary outcomes were death, discharge, drop-out. RESULTS: 427, 346, 549 patients were admitted in 2005, 2006, 2007, respectively. Mortality dropped from 26.46% in 2005 to 18.76% in 2007 (p-value 0.003), due to the significant reduction in rainy season mortality (death/discharge ratio: 0.79, 0.55 and 0.26 in 2005, 2006 and 2007 respectively; p-value 0.001) while dry season mortality remained constant (0.39, 0.37 and 0.32; p-value 0.647). Costs of malaria prevention were limited: 2€/person. No drop-outs were observed. Health education attendance was 96-99%. CONCLUSIONS: Malaria prevention in African tertiary care hospitals seems feasible with limited costs. Vector control, personal protection and cotrimoxazole prophylaxis seem to reduce mortality in severely ill TB patients. Prospective randomized trials are needed to confirm our findings in similar settings. TRIAL REGISTRATION NUMBER: Current Controlled Trials: ISRCTN8394430