Photosynthesis down-regulation precedes carbohydrate accumulation under sink limitation in Citrus.

Photosynthesis down-regulation due to an imbalance between sources and sinks in Citrus leaves could be mediated by excessive accumulation of carbohydrates. However, there is limited understanding of the physiological role of soluble and insoluble carbohydrates in photosynthesis regulation and the elements triggering the down-regulation process. In this work, the role of non-structural carbohydrates in the regulation of photosynthesis under a broad spectrum of source-sink relationships has been investigated in the Salustiana sweet orange.

Discrete Laplacian recordings of the electroenterogram from abdominal surface in humans.

The first aim of this study was to obtain the discrete Laplacian of the myoelectric small intestine signal (electroenterogram, EEnG) from bipolar recordings on the abdominal surface in humans. In addition, the objective was to identify the slow wave (SW) component of the EEnG in the estimated Laplacian, as well as to compare this signal with the bipolar surface recordings. It was carried out 8 recording sessions in 6 healthy volunteers.

Signal noise ratio of small intestine myoelectrical signal recorded from external surface.

Electroenterogram (EEnG), which is the myoelectrical activity of the small bowel, can be non-invasively recorded from abdominal external surface. However, this bioelectrical signal is weak and noisy compared to internal recording from bowel serous layers, because of bioelectric transmission through abdominal layers. Furthermore, it is contaminated with several interferences from other biological activities as cardiac muscle (ECG), skeletal muscles (EMG), or respiration movements.