Soil quality parameters of a xanthic ferralsol in the Amazon basin.

A Fertbio 2002 reuniu a XXV Reunião Brasileira de Fertilidade do Solo e Nutrição de Plantas, a IX Reunião Brasileira sobre Micorrizas, o VII Simpósio Brasileiro de Microbiologia do Solo e a Reunião Brasileira de Biologia do Solo, sob o tema: "Agricultura: bases ecológicas para o desenvolvimento social e econômico sustentado

Development and production of several tropical species in agroforestry systems in the Brazilian Central Amazonia during six years.

In the Central Amazonia, large land area nowadays are degraded and/or abandoned, which were previously used for shifting cultivation, pasture or monocultures. Agroforestry systems appear to be a good alternative to occupy these areas

Economic analysis of agroforestry systems in Central Amazonia, Brazil.

In this study the financial analysis of four AF was made

Development and production of cupuaçu plants (Theobroma grandiflorum) on degraded areas: implications of water relations.

In the study presented here we investigated the development and production of the crop tree Theobroma grandiflorum (in Brazil named "cupuaçu") under varying agro-environments

Comportamento de bananeiras submetidas a diferentes níveis de sombreamento.

Objetiva-se avaliar, por meio de cultivos intercalares e em trilhas na capoeira, a influência dos diferentes níveis de sombreamento na incidência da Sigatoka negra.bitstream/item/89173/1/PA-35-Mirza.pd

Reasons to withhold intra-arterial thrombolysis in clinical practice

Background: In selected stroke centers intra-arterial thrombolysis (IAT) is used for the treatment of acute stroke patients presenting within 6hours of symptom onset. However, data about eligibility of acute stroke patients for IAT in clinical practice are very scarce. Methods: We collected prospectively data on indications advising for or against IAT of 230 consecutive stroke patients in a tertiary stroke center. Results: 76 patients (33.0%) presented within 3hours, 69 (30%) between 3 and 6hours of symptom onset and 85 (37%) later than 6hours. Arteriography was performed in 71 patients (31%) and IAT in 46 (20%). In 11 patients no or only peripheral branch occlusions were seen on arteriography and therefore IAT was not performed. In 9 patients the ICA was occluded and barred IAT and in five anatomical or technical difficulties made IAT impossible. 72 patients presenting within 6hours did not undergo arteriography and thrombolysis, mostly because of mild (n=44) or rapidly improving neurological deficits (n=13). Other reasons to withhold IAT were CT and/or clinical findings suggesting lacunar stroke due to small vessel occlusion (n=7), limiting comorbidty (n=7) and baseline international normalized ratio>1.7 (n=1). Conclusions: A third of the patients underwent diagnostic arteriography and one fifth received IAT. The most important reasons to withhold thrombolysis were presentation beyond the 6hours time window and mild or rapidly improving symptom

Water and nutrient flux measurements.

bitstream/item/180984/1/ID-3848-5-11.pd

Distribution of throughfall and stemflow in agroforestry, perennial monoculture, fallow and primary forest in the central Amazon, Brazil.

bitstream/item/180983/1/ID-3848-12-31.pd

Diffusion-weighted MRI in acute spinal cord ischaemia

Abstract : Acute spinal cord ischaemia is often undetectable with conventional MRI. Diffusion-weighted MRI (DWI) has been difficult to use in the spine because of susceptibility artefacts. We assessed the diagnostic value of echoplanar DWI for early confirmation of spinal cord ischaemia. We performed conventional MRI and DWI in two men and three women, aged 54-75years with clinically suspected acute spinal cord ischaemia. Imaging was performed 9-46h after the onset of symptoms, and 2-9days later to assess the extent of ischaemic signal change. Spatial resolution of DWI within the spine using standard equipment was poor, but in all patients, early DWI revealed areas of high signal indicating decreased diffusion, confirmed by measurement of apparent diffusion coefficients. Follow-up MRI showed high signal on T2-weighted images and contrast enhancement at the expected levels. Neurological deficits corresponded with radiological findings in four patients: various syndromes, including isolated bilateral weakness or sensory change and combined deficits, were found. Echoplanar DWI may be helpful for confirmation of spinal cord ischaemia in the acute stage, but follow-up T2-weighted images have superior spatial resolution and correlation with clinical findings and lesion exten

Locally induced hypothermia for treatment of acute ischaemic stroke: a physical feasibility study

During the treatment of stroke by local intra-arterial thrombolysis (LIT) it is frequently possible to pass the blood clot with a micro-catheter, allowing perfusion of brain tissue distally to the occlusion. This possibility allows for new early treatments of ischaemic brain tissue, even before the blood clot has been removed. One potential new approach to preserve brain tissue at risk may be locally induced endovascular hypothermia. Physical parameters such as the required micro-catheter input pressure, output velocity and flow rates, and a heat exchange model, applicable in the case of a micro-catheter placed within a guiding catheter, are presented. Also, a simple cerebral temperature model is derived that models the temperature response of the brain to the perfusion with coolant fluids. Based on this model, an expression has been derived for the time needed to reach a certain cerebral target temperature. Experimental in vitro measurements are presented that confirm the usability of standard commercially available micro-catheters to induce local hypothermia of the brain. If applied in vivo, the model predicts a local cooling rate of ischaemic brain tissue of 300g of approximately 1°C in 1min, which is up to a factor 30-times faster than the time-consuming systemic hypothermia via the skin. Systemic body temperature is only minimally affected by application of local hypothermia, thus avoiding many limitations and complications known in systemic hypothermi