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1.
Phys Rev Lett ; 129(10): 102701, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36112434

RESUMO

Carbon burning is a key step in the evolution of massive stars, Type 1a supernovae and superbursts in x-ray binary systems. Determining the ^{12}C+^{12}C fusion cross section at relevant energies by extrapolation of direct measurements is challenging due to resonances at and below the Coulomb barrier. A study of the ^{24}Mg(α,α^{'})^{24}Mg reaction has identified several 0^{+} states in ^{24}Mg, close to the ^{12}C+^{12}C threshold, which predominantly decay to ^{20}Ne(ground state)+α. These states were not observed in ^{20}Ne(α,α_{0})^{20}Ne resonance scattering suggesting that they may have a dominant ^{12}C+^{12}C cluster structure. Given the very low angular momentum associated with sub-barrier fusion, these states may play a decisive role in ^{12}C+^{12}C fusion in analogy to the Hoyle state in helium burning. We present estimates of updated ^{12}C+^{12}C fusion reaction rates.

2.
S Afr Med J ; 109(11b): 53-56, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-32252869

RESUMO

A high-level review was conducted of the literature pertaining to the challenges and opportunities for eliminating malaria on the African continent. Although malaria mortality and morbidity are on the decline, the disease remains one of public health importance. Africa has invariably borne the brunt of the disease, recording the highest number of cases and deaths. However, with greater emphasis being placed on the disease by the international community, partnerships have developed to boost malaria elimination efforts on the continent. One such initiative is the Roll Back Malaria (RBM) partnership which aims to facilitate malaria elimination through increasing resources and awareness. Many cross-border initiatives have been established which treat malaria as a regional problem rather than a country-specific one. Accelerated malaria control efforts have led to a 37% decrease in cases and 60% reduction in deaths. Multi-country efforts have resulted in marked reductions of transmission in the region. Although there have been noteworthy gains in curtailing the disease, new challenges have arisen. The main among these are residual malaria and outdoor biting. One of the main drivers of residual malaria is insecticide resistance. Adding to the burden of residual transmission is the discovery of new vectors that may exist at low densities. To exacerbate these issues is the challenge of malaria imported from high- to low-transmission areas. Nevertheless, compared with the historical picture, we are winning the battle against malaria. Countries in Africa are being certified malaria-free. Partnerships have been developed to take forward the RBM Global Malaria Action Plan. Elimination agendas can only be successful if funding remains sustainable, with greater reliance on domestic funding.


Assuntos
Antimaláricos/uso terapêutico , Erradicação de Doenças , Resistência a Medicamentos , Resistência a Inseticidas , Malária Falciparum/tratamento farmacológico , Malária Falciparum/prevenção & controle , África , África Subsaariana , Animais , Anopheles/parasitologia , Anopheles/fisiologia , Humanos , Mosquiteiros Tratados com Inseticida , Cooperação Internacional , Malária/tratamento farmacológico , Malária/prevenção & controle , Plasmodium falciparum/fisiologia
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