RESUMO
Tropical ecosystems are central to the global focus on halting and reversing habitat destruction as a means of mitigating carbon emissions. Brazil has been highlighted as a vital part of global climate agreements because, whilst ongoing land-use change causes it to be the world's fifth biggest greenhouse gas emitting country, it also has one of the greatest potentials to implement ecosystem restoration. Global carbon markets provide the opportunity of a financially viable way to implement restoration projects at scale. However, except for rainforests, the restoration potential of many major tropical biomes is not widely recognised, with the result that carbon sequestration potential may be squandered. We synthesize data on land availability, land degradation status, restoration costs, area of native vegetation remaining, carbon storage potential and carbon market prices for 5475 municipalities across Brazil's major biomes, including the savannas and tropical dry forests. Using a modelling analysis, we determine how fast restoration could be implemented across these biomes within existing carbon markets. We argue that even with a sole focus on carbon, we must restore other tropical biomes, as well as rainforests, to effectively increase benefits. The inclusion of dry forests and savannas doubles the area which could be restored in a financially viable manner, increasing the potential CO2e sequestered >40 % above that offered by rainforests alone. Importantly, we show that in the short-term avoiding emissions through conservation will be necessary for Brazil to achieve it's 2030 climate goal, because it can sequester 1.5 to 4.3 Pg of CO2e by 2030, relative to 0.127 Pg CO2e from restoration. However, in the longer term, restoration across all biomes in Brazil could draw down between 3.9 and 9.8 Pg of CO2e from the atmosphere by 2050 and 2080.
Assuntos
Sequestro de Carbono , Ecossistema , Brasil , Análise Custo-Benefício , Florestas , Carbono , Conservação dos Recursos NaturaisRESUMO
Fatty acid uptake, distribution, and beta-oxidation were investigated in Leishmania mexicana amastigotes. The uptake of radiolabeled palmitic, stearic, and oleic acids was similar, reaching 3-6 nmol/10(8) cells in 2 min and 8-12 nmol/10(8) cells in 60 min. The percent of radiolabeled fatty acid that was esterified in the form of triglycerides or phospholipids increased from less than 25% at 2 min to 65-86% at 60 min. The dehydrogenase(s) in an amastigote granule fraction were unusual in that the Vmax for long-chain substrates (0.95-1.6 delta Abs units/min-mg protein) approximated the Vmax for short-chain substrates (0.82-2.0 delta Abs units/min-mg protein), and the Km for long-chain substrates was high (approximately 250 microM), in contrast to data for a mammalian liver mitochondrial fraction. The high Vmax and Km for long-chain substrates suggest a biochemical mechanism for the postulated high utilization of fatty acids as an energy source for amastigotes. Although the primary anti-leishmanial agent, Sb in the form of Pentostam, inhibited oxidation of palmitic acid to CO2 by intact organisms, Sb did not significantly inhibit fatty acid uptake or esterification by organisms, or beta-oxidation by the granule fraction, and the mechanism of action of Sb remains unclear.
Assuntos
Ácidos Graxos/metabolismo , Leishmania mexicana/metabolismo , Acil-CoA Desidrogenase , Gluconato de Antimônio e Sódio/farmacologia , Ácidos Graxos Dessaturases/análise , Cinética , Oxirredução , Ácido Palmítico , Ácidos Palmíticos/metabolismoRESUMO
Since May 1979, 190 rodents in the family Sciuridae, representing three genera and nine species, have been collected in the western United States and northern Mexico and examined for coccidia; 71 (37%) had coccidian oocysts in their feces. These included 2 of 12 (17%) Eutamias canipes; 7 of 12 (58%) E. dorsalis; 18 of 50 (36%) E. merriami; 33 of 96 (34%) E. obscurus; 3 of 4 (75%) E. townsendii; 3 of 9 (33%) Sciurus aberti; 1 of 1 S. griseus; 1 of 1 Tamiasciurus hudsonicus mogollonensis; and 3 of 5 (60%) T. mearnsi. The following coccidians were identified from infected rodents: Eimeria cochisensis n. sp. and Eimeria dorsalis n. sp. from E. canipes, E. cochisensis, E. dorsalis, and E. tamiasciuri from E. dorsalis, E. dorsalis and E. tamiasciuri from E. merriami; E. cochisensis, E. dorsalis, E. tamiasciuri, and E. wisconsinensis from E. obscurus; E. cochisensis and E. dorsalis from E. townsendii; E. ontarioensis and E. tamiasciuri from S. aberti; E. tamiasciuri from S. griseus; E. tamiasciuri and E. toddi from T. h. mogollonensis; and E. tamiasciuri from T. mearnsi. Sporulated oocysts of Eimeria dorsalis n. sp. were ovoid, 21.9 x 16.8 (17-24 x 14-20) micrometer with sporocysts ovoid, 11.5 x 6.9 (10-14 x 6-8) micrometer. Sporulated oocysts of Eimeria cochisensis n. sp. were spheroid to subspheroid, 16.7 x 15.3 (15-18 x 14-17) micrometer, with sporocysts ovoid, 8.4 x 5.6 (6-11 x 4-7) micrometer. Fifty-five of 71 (77%) infected hosts had oocysts of only one eimerian species in their feces at the time they were examined. One eimerian, E. tamiasciuri, was found in seven of nine host species in three genera. A list is provided of all eimerians (22, including the species described here) that have been described in the literature from Eutamias, Sciurus, and Tamiasciurus spp.
Assuntos
Coccidiose/veterinária , Eimeria/classificação , Doenças dos Roedores/parasitologia , Sciuridae/parasitologia , Animais , Coccidiose/parasitologia , Eimeria/citologia , México , Terminologia como Assunto , Estados UnidosRESUMO
Journal Royal sanitary Institute, vol 44, No. 8, p. 294-300