Predictable waves of sequential forest degradation and biodiversity loss spreading from an African city.

Tropical forest degradation emits carbon at a rate of approximately 0.5 Pgxy(-1), reduces biodiversity, and facilitates forest clearance. Understanding degradation drivers and patterns is therefore crucial to managing forests to mitigate climate change and reduce biodiversity loss. Putative patterns of degradation affecting forest stocks, carbon, and biodiversity have variously been described previously, but these have not been quantitatively assessed together or tested systematically. Economic theory predicts a systematic allocation of land to its highest use value in response to distance from centers of demand. We tested this theory to see if forest exploitation would expand through time and space as concentric waves, with each wave targeting lower value products. We used forest data along a transect from 10 to 220 km from Dar es Salaam (DES), Tanzania, collected at two points in time (1991 and 2005). Our predictions were confirmed: high-value logging expanded 9 kmxy(-1), and an inner wave of lower value charcoal production 2 kmxy(-1). This resource utilization is shown to reduce the public goods of carbon storage and species richness, which significantly increased with each kilometer from DES [carbon, 0.2 Mgxha(-1); 0.1 species per sample area (0.4 ha)]. Our study suggests that tropical forest degradation can be modeled and predicted, with its attendant loss of some public goods. In sub-Saharan Africa, an area experiencing the highest rate of urban migration worldwide, coupled with a high dependence on forest-based resources, predicting the spatiotemporal patterns of degradation can inform policies designed to extract resources without unsustainably reducing carbon storage and biodiversity.

Renal haemodynamic responses to a chicken or beef meal in normal individuals.

BACKGROUND: In normal subjects, protein loading with soybean meal does not produce the same renal haemodynamic effects as those observed with a beef meal. The renal responses of an acute protein load in the form of chicken meal is unknown. METHODS: To examine whether the renal response to a chicken meal differs from that to beef, we studied the renal function of eight normal healthy volunteers before and after a protein load with each of these meals. In a crossover randomized study, we measured the glomerular filtration rate (GFR; inulin clearance), renal plasma flow (RPF; para-aminohippurate clearance) and, plasma amino acid and glucagon levels. We also determined the amino acid content of a sample of chicken and beef. RESULTS: GFR and RPF increased significantly 2 h after both the chicken and beef meals (chicken, 98+/-13 vs 119+/-18 and 476+/-123 vs 570+/-99 ml/min/1.73 m2; beef, 107+/-14 vs 122+/-16 and 501+/-118 vs 560+/-97 ml/min/1.73 m2, for GFR and RPF at basal and 2 h respectively, P<0.05). Renal vascular resistance decreased and the filtration fraction remained unchanged after both protein loads. The changes induced by the protein challenges in the plasma amino acid and glucagon levels were not different between the two protein sources. The amino acid contents of chicken and beef samples were similar. CONCLUSION: In normal subjects, chicken and beef meals induced a similar degree of hyperfiltration.

Acute tubulointerstitial nephritis and uveitis with antineutrophil cytoplasmic antibody.

We report a case of acute tubulointerstitial nephritis and uveitis (TINU syndrome) in a 47-year-old woman who also was found to have antineutrophil cytoplasmic antibody. The patient developed severe acute renal failure that improved after a high dose (1 mg/kg/d) of corticosteroid therapy. The diagnosis of the disorder is discussed, as well as the finding of antineutrophil cytoplasmic antibody.

Insuficiencia renal aguda por malaria / Acute renal failure due to malaria

Em nosso pais, a malaria apresenta elevada incidencia, principalmente nas regioes Norte e Centro-Oeste.O objetivo deste trabalho e relatar a observacao de 20 em 1.272 casos (1.6%) de malaria que apresentaram insuficiencia renal aguda (IRA) necessitando tratamento por dialise peritoneal (DP), no Hospital de Vila Permanente da Usina Hidreletrica de Tucurui (PA), na Amazonia brasileira. Dos 20 pacientes submetidos a DP, 6 (3%) evoluiram para obito, frequencia menor do que a esperada para a IRA de uma maneira geral quando, em media, 50% apresentam mortalidade. Nao houve diferenca significativa da creatinina, ureia, bilirrubinas, transaminases, hemoglobina, eletrolitos ou da contagem de plaquetas entre os pacientes que evoluiram para a alta hospitalar ou para obito. Entretanto, a intensidade da infestacao parasitaria, a leucocitose e a presenca de acidose metabolica sao parametros desfavoraveis na evolucao destes pacientes Os autores concluem que a IRA, associada a malaria, tem menor mortalidade que a IRA em geral, e que a equipe medica deve estar preparada para propiciar atendimento especializado, em particular nas regioes de maior incidencia desta patologia