Enhancing governance in fisheries management in southeast Asia towards 2020: issues and perspectives

This is a keynote address at the ASEAN-SEAFDEC conference on Sustainable Fisheries for Food Security Towards 2020, Fish for the People 2020: Adaptation to a Changing Environment. It addresses theme one of the conference which is Enhancing Governance in Fisheries Management. With the deteriorating state of the fishery resources and the emerging fisheries-related issues during the past decade, there is an urgent need to address concerns on weak governance as the main underlying cause of overfishing. Many social scientists believe that improved governance with strong elements of self-governance, co-management, and community-based management are required for effective management of fisheries resources.Fisheries Management, Governance, Co-management, Southeast Asia.

Distinct stick-slip modes in adhesive polymer interfaces

Stick-slip, manifest as intermittent tangential motion between two solids, is a well-known friction instability that occurs in a number of natural and engineering systems. In the context of adhesive polymer interfaces, this phenomenon has often been solely associated with Schallamach waves, which are termed slow waves due to their low propagation speeds. We study the dynamics of a model polymer interface using coupled force measurements and high speed \emph{in situ} imaging, to explore the occurrence of stick-slip linked to other slow wave phenomena. Two new waves---slip pulse and separation pulse---both distinct from Schallamach waves, are described. The slip pulse is a sharp stress front that propagates in the same direction as the Schallamach wave, while the separation pulse involves local interface detachment and travels in the opposite direction. Transitions between these stick-slip modes are easily effected by changing the sliding velocity or normal load. The properties of these three waves, and their relation to stick-slip is elucidated. We also demonstrate the important role of adhesion in effecting wave propagation.Comment: 22 pages, 9 figure

A Conformal Field Theory of Extrinsic Geometry of 2-d Surfaces

In the description of the extrinsic geometry of the string world sheet regarded as a conformal immersion of a 2-d surface in $R^3$, it was previously shown that, restricting to surfaces with $h\surd{g}\ =\ 1$, where $h$ is the mean scalar curvature and $g$ is the determinant of the induced metric on the surface, leads to Virasaro symmetry. An explicit form of the effective action on such surfaces is constructed in this article which is the extrinsic curvature analog of the WZNW action. This action turns out to be the gauge invariant combination of the actions encountered in 2-d intrinsic gravity theory in light-cone gauge and the geometric action appearing in the quantization of the Virasaro group. This action, besides exhibiting Virasaro symmetry in $z$-sector, has $SL(2,C)$ conserved currents in the $\bar{z}$-sector. This allows us to quantize this theory in the $\bar{z}$-sector along the lines of the WZNW model. The quantum theory on $h\surd{g}\ =\ 1$ surfaces in $R^3$ is shown to be in the same universality class as the intrinsic 2-d gravity theory.Comment: 30 page