Quantifying the biodiversity value of tropical primary, secondary, and plantation forests.

Biodiversity loss from deforestation may be partly offset by the expansion of secondary forests and plantation forestry in the tropics. However, our current knowledge of the value of these habitats for biodiversity conservation is limited to very few taxa, and many studies are severely confounded by methodological shortcomings. We examined the conservation value of tropical primary, secondary, and plantation forests for 15 taxonomic groups using a robust and replicated sample design that minimized edge effects. Different taxa varied markedly in their response to patterns of land use in terms of species richness and the percentage of species restricted to primary forest (varying from 5% to 57%), yet almost all between-forest comparisons showed marked differences in community structure and composition. Cross-taxon congruence in response patterns was very weak when evaluated using abundance or species richness data, but much stronger when using metrics based upon community similarity. Our results show that, whereas the biodiversity indicator group concept may hold some validity for several taxa that are frequently sampled (such as birds and fruit-feeding butterflies), it fails for those exhibiting highly idiosyncratic responses to tropical land-use change (including highly vagile species groups such as bats and orchid bees), highlighting the problems associated with quantifying the biodiversity value of anthropogenic habitats. Finally, although we show that areas of native regeneration and exotic tree plantations can provide complementary conservation services, we also provide clear empirical evidence demonstrating the irreplaceable value of primary forests.

Laparoscopic cholecystectomy in children and adolescents.

During the period between August 1991 and November 1995, seven patients under age 17 were submitted to videolaparoscopic cholecystectomy (LC). Two were males and five females with ages ranging from 12 to 16 years (mean 13.8 years). The diagnosis of chronic cholecystitis with gallstones was made by the clinical history and physical and ultrasonographic examinations. There was no evidence of an association with hemolytic diseases, familial hyperlipidemia or Glucose-6-phosphate dehydrogenase (G6PD) deficiency. The surgery was performed under general anesthesia and the abdomen approached by four ports: a 10 mm umbilical incision, a 5 mm cystic, a 5 mm one at the xiphoid appendix and a 10 mm one at the left lateral margin of the left rectus abdominal muscle between the umbilical scar and the xiphoid appendix. Operative time averaged 120 minutes (105-150 min). One case required conversion to laparotomic approach because of Mirizzi's Syndrome, which was diagnosed by intraoperative cholangiography performed in all cases. There were no deaths or major postoperative complications. Hospital stays ranged from 1-3 days in the six patients submitted to LC. Thus LC in children can be considered a good method, requiring only more care regarding the use of proper equipment, complete and careful dissection of the biliary hilus, and intraoperative cholangiography. The latter is indispensable, as these children can present a higher rate of anatomic anomalies. The advantages of this techniques include a less painful postoperative period with a faster recovery, and it is especially recommended in children, who are less tolerant to physical restriction and pain than adults.