More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia

Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state.

Impact of copper sulfate application at an urban Brazilian reservoir: A geostatistical and ecotoxicological approach

A landscape ecotoxicology approach was used to assess the spatial distribution of copper in the recent bottom sediment (surficial sediment) of a Brazilian subtropical reservoir (the Guarapiranga reservoir) and its potential ecotoxicological impacts on the reservoir ecosystem and the local society. We discuss the policies and procedures that have been employed for the management of this reservoir over the past four decades. Spatial heterogeneity in the reservoir was evaluated by means of sampling design and statistical analysis based on kriging spatial interpolation. The sediment copper concentrations have been converted into qualitative categories in order to interpret the reservoir quality and the impacts of management policies. This conversion followed the Canadian Water Framework Directive (WFD) ecotoxicological concentration levels approach, employing sediment quality guidelines (SQGs). The SQG values were applied as the copper concentration thresholds for quantitative-qualitative conversion of data for the surficial sediment of the Guarapiranga. The SQGs used were as follows: a) interim sediment quality guideline (ISQG), b) probable effect level (PEL), and c) regional reference value (RRV). The quantitative results showed that the spatial distribution of copper in the recent bottom sediment reflected the reservoir's management policy and the copper application protocol, and that the copper concentrations varied considerably, ranging from virtually-zero to in excess of 3g_copper/kg_ds. The qualitative results demonstrated that the recent bottom sediment was predominantly in a bad or very bad condition, and could therefore have impacts on the local society and the ecosystem. It could be concluded that the management policy for this reservoir was mainly determined by the desire to minimize short-term costs, disregarding long-term socioeconomic and environmental consequences.

Haemodynamic changes after spinal cord transection are anaesthetic agent dependent

1 To evaluate the effect of high spinal cord transection (SCT), between T4 and T5, on the mean arterial pressure (MAP) and heart rate in animals anaesthetized with different anaesthetic agents: ether (n = 12), 20% urethane, 1.2 g kg(-1) (n = 12), 2% tri-bromide-ethanol, 200 mg kg(-1) (n = 12); chloral hydrate and urethane, 75 and 525 mg kg(-1) respectively (n = 12). 2 In the animals anaesthetized with ether or urethane, SCT caused an immediate major drop in MAP, with hypotension and bradycardia throughout the next 10 min. In the animals anaesthetized with urethane + chloralose or tri-bromide-ethanol, SCT transiently increased MAP with subsequent hypotension and bradycardia. 3 In summary, the haemodynamic changes after complete, high SCT are anaesthetic agent dependent. Further research about the exact mechanisms responsible for these diverse autonomic changes is warranted.

Gastric emptying and gastrointestinal transit of liquid throughout the first month after thoracic spinal cord transection in awake rats

Spinal cord transection (SCT) inhibits gastrointestinal motility in awake rats. We studied the gastric emptying (GE) and gastrointestinal transit of liquid throughout the first month after thoracic SCT. Male Wistar rats (N = 66) were submitted to laminectomy followed or not by complete SCT between T4 and T5 vertebrae. Phenol red recovery in the stomach, proximal, mid-and distal small intestine was determined 1, 7, 10, 15, and 30 days thereafter. Gastric recovery increased by 51.2 and 38.9% and mid-intestinal recovery decreased by 45.5 and 66.6% at one and seven days after SCT (P < 0.05). Proximal small intestine recovery increased by 45.9% 10 days after SCT but no inhibition of gastrointestinal motility was observed thereafter. Stool output significantly decreased in the first seven days after SCT (P < 0.05). In summary, gastrointestinal motility in awake rats is inhibited throughout the first 10 days after thoracic SCT but not thereafter.

A plethysmometric method for gastric compliance studies in anesthetized rats

A new method to study gastric volume by plethysmography is presented. Twenty male Wistar rats (250-300 g) were fasted for 24 h. After anesthesia with urethane (1.2 g/kg, i.p.), a tracheostomy was performed, and cervical vessels were cannulated. A balloon catheter was introduced per os and positioned in the proximal stomach. The opposite end of the catheter was connected to a reservoir (volume = 30 ml; inside diameter = 2.5 cm), coupled to a plethysmometer. A standard ionic solution was used to fill the balloon ( approximately 3.0 ml) and the communicating vessel system. Calibration experiments (n = 5) displayed a strong (r(2) = 0.99) correlation between graded balloon-volume changes and plethysmometric recordings. Because distending pressure of the stomach remained constant, the balloon-volume recordings were taken as gastric compliance index. Gastric volume changes, mean arterial pressure, and heart rate of animals of control and experimental groups were monitored for 90 min. The data were analyzed by analysis of variance and the Student-Newman-Keuls test. In control animals (n = 5), no significant changes on gastric volume and hemodynamic values were found. Experimental animals were treated with either yohimbine (n = 5) or bethanechol (n = 5) i.v. injections. The rats received consecutive doses of yohimbine (0.5 and 1 mg/kg) or bethanechol (1.5 and 3 microg/kg), 30 min apart. Both doses of each treatment transiently induced hypotension and bradycardia (p < 0.05). Yohimbine treatment (1 mg/kg) increased gastric volume by half (p < 0.05), whereas bethanechol (3 microg/kg) decreased it by 35% (p < 0.05). In summary, this work shows a suitable method to directly assess gastric compliance in anesthetized rats.

Breast reconstruction by expansion and advancement of the upper abdominal flap

Inspired by successful reconstruction obtained using the Lewis-Ryan lower thoracic advancement flap to rebuild missing breast, we have adapted that extremely simple technique to prior serial expansions, in order to create more natural mounds, better defined submammary folds, and when possible, some grade of ptosis, without additional, new scarring. The procedure is introduced and compared to other such flaps as the TRAM and the latissimus dorsii. In our series, 30 patients were evaluated according to the quality of the final results, and the most frequent complication are pointed out and discussed.