Impedance control is tuned to multiple directions of movement

Humans are able to learn tool-handling tasks, such as carving, demonstrating their competency to make and vary the direction of movements in unstable environments. It has been shown that when a single reaching movement is repeated in unstable dynamics, the central nervous system (CNS) learns an impedance internal model to compensate for the environment instability. However, there is still no explanation for how humans can learn to move in various directions in such environments. In this study, we investigated whether and how humans compensate for instability while learning two different reaching movements simultaneously. Results show that when performing movements in two different directions, separated by a 35° angle, the CNS was able to compensate for the unstable dynamics. After adaptation, the force was found to be similar to the free movement condition, but stiffness increased in the direction of instability, specifically for each direction of movement. Our findings suggest that the CNS either learned an internal model generalizing over different movements, or alternatively that it was able to switch between specific models acquired simultaneously. © 2008 IEEE.

Broodstock management: an integral part of hatchery techniques

The paper presents bighead carp broodstock management, an integral part of hatchery techniques as it will determine the quality of resulting fry and fingerlings. Proper methods on the selection and management of broodstock are discussed.

AQD's breeding-hatchery techniques

Details are given of standardized methods used by AQD for the spawning of seabass (Lates calcarifer) and the rearing of fry in the hatchery.

Village level processing techniques

The agar-bearing seaweeds Gracilaria and Gelidium grow abundantly in the Asia-Pacific region. Production and post-harvest techniques and methods for processing Gracilaria to produce agar suitable for local market is necessary to increase the meager income of coastal dwellers. A flow diagram of a village level agar production is provided. A guide is also given for the quality of dried seaweeds, which are divided into 3 classes.

Farming techniques for seaweeds

Details are given of farming methods developed by the SEAFDEC Aquaculture Department for 3 different seaweeds: 1) Bottom line culture method for Kappaphycus; 2) Pond culture of Gracilaria; and, 3) Gracilariopsis bailinae, the new seaweed on the block.