1,183 research outputs found
Uniformização dos zoneamentos ecológico-econômicos de áreas adjacentes.
O objetivo foi avaliar as diferenças de zoneamento na área fronteiriça do ZEE da sub-bacia do Purus (COMISSÃO ESTADUAL..., 2011) e do ZEE do Acre (ACRE, 2010)
Soil Carbon and Nitrogen Dynamics of Integrated Crop-Pasture Systems with Annual and Perennial Forages
Increased demand for food and bioenergy crops and the subsequent intensification of crop production creates a challenge for the conservation of natural resources in Latin America and the world. In Uruguay, no-till cash-crop production area has increased from 0.4 to 1.5 million ha in the last decade (DIEA 2011) mostly at the expense of pastureland through expanding grain production to soils with lower land use capability. Production systems based on crop-pasture rotations shifted to a longer annual cropping phase with a shorter pasture phase, or to continuous annual crop-ping. Long-term experiments in the country have shown that the rotation of annual crops and perennial pastures minimizes soil erosion in tilled systems, maintaining a positive long-term soil carbon (C) and nitrogen (N) balance that contrasts with C and N losses in annual cropping systems (García-Préchac et al. 2004). Research and extension on soil conservation in crop-pasture systems have led to a massive adoption of no-tillage practices, reaching about 90% of cash crop area by the 2009 growing season (DIEA 2011). However, the gradual increase in no-till adoption by farm operators has been associated with a dramatic increase in continuous annual cropping to the detriment of the pasture phase of the rotation.
Our overarching question is: What is the impact of an increased frequency of annual crops in the C and N cycling of these systems? The objective of this study was to assess the impact of the pasture phase and cropping intensity on the soil C and N cycling of an Oxyaquic Argiudoll soil of eastern Uruguay using long term field experimental data and a cropping systems simulation model
The normal ischiofemoral distance and its variations.
The aim of this study is to measure the ischiofemoral distance (IFD) in the normal hip with healthy surrounding soft tissues and describe its variations caused by gender, age and proximal femoral anatomy so that this could serve as a reference for future studies on this subject. This is a retrospective study in which we reviewed the CT scans of 149 patients (298 hips) who had a CT of their pelvis for non-orthopaedic (abdomino-pelvic) pathology. The images were reviewed by two independent observers and the IFD (the smallest distance between the lateral cortex of the ischial tuberosity and the posteromedial cortex of the lesser trochanter), offset (the perpendicular distance from the centre of the femoral head to a line running down the middle of the shaft of the femur) and the neck-shaft angle (the angle between the lines in the middle of the neck to the line forming the axis of the femoral shaft) were measured. The CT scans belonged to 71 males and 78 females (M: 48%, F: 52%), with an average age of 51 ± 19 years (range 18-92). The mean IFD was 18.6 ± 8 mm in the females and 23 ± 7 mm in the males and this difference was statistically significant (P < 0.001). The IFD increased by 1.06 mm for each 1 mm of offset and dropped by 0.09 mm with each year of age. However, the neck-shaft angle did not show any significant correlation with the IFD.This is the final version of the article. It first appeared from Oxford University Press via http://dx.doi.org/10.1093/jhps/hnw00
Azorean Coastal Communities. An On-going Study.
43rd European Marine Biology Symposium. Ponta Delgada, Açores, 8-12 de Setembro de 2008
Fast direct determination of titanium dioxide in toothpastes by X-Ray fluorescence and multivariate calibration
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