Climate Change and Crop Yield Distribution: Some New Evidence From Panel Data Models

This study examines the impact of climate on the yields of seven major crops in Taiwan based on pooled panel data for 15 prefectures over the 1977-1996 period. Unit-root tests and maximum likelihood methods involving a panel data model are explored to obtain reliable estimates. The results suggest that climate has different impacts on different crops and a gradual increase in crop yield variation is expected as global warming prevails. Policy measures to counteract yield variability should therefore be carefully evaluated to protect farmers from exposure to these long-lasting and increasingly climate-related risks.Yield response, Climate change, Panel data, Unit-root test

ON THE EQUIVALENCE OF IMPORT TARIFF AND QUOTA: THE CASE OF RICE IMPORT IN TAIWAN

This paper extends the existing theory on the equivalence of import tariff and quota. If the equivalence is defined on the domestic price level (weak equivalence), then either the zero conjectural variation for domestic country or a perfectly competitive market will be sufficient to support this equivalence. If the equivalence is defined both on the same domestic price level as well as tariff rate (strong equivalence), then the conditions are that either domestic country acts as a Cournot competitor and foreign country is a price taker, or both domestic and foreign country are price takers. An empirical spatial-equilibrium trade model is constructed to simulate the impacts of import tariff and quota. Using Taiwan¡¦s rice import as an example, the empirical results show that if Taiwan switches from the quota system to tariff system, the domestic rice price as well as total social welfare can be increased given the same import volume.International Relations/Trade,

Auto-adhesive transdermal drug delivery patches using beetle inspired micropillar structures

The patch described in this paper combines the principles of wet adhesion, which is a widely adopted biological adhesion system in nature, with transdermal drug delivery. A biologically inspired micropillar patch was fabricated that is self-adhesive, reusable, and can sustain a controlled drug release. We successfully preloaded the commercial non-steroidal anti-inflammatory generic drug unguents indomethacin, ketoprofen, diclofenac sodium and etofenamate into a polydimethylsiloxane elastomeric matrix and fabricated drug-containing micropillar patches. When examining the drug release kinetics and friction of the patches, we observed that these drug unguents can be released calculably and regularly for several days. Additionally, the drug unguents released from the patch to its attached surface are critical to increase the strength of the patch's adhesion, which is based on capillary attractive forces and is inspired by beetle feet. Here, we create a novel system combining biomimetics and drug delivery that can be modified for use across the biomedical and engineering spectra. Motivation: the objective of the present study was to characterize a micropillar PDMS patch that was inspired by a beetle's wet adhesion as a platform for conducting in vitro release studies. Commercially available non-steroid anti-inflammatory drugs (NSAIDs) were used as the model drugs for our delivery systems. An emphasis was put on quantitatively evaluating the drug release and friction manifestation of these patches

Fabrication, modeling, and characterization of form-birefringent nanostructures

A 490-nm-deep nanostructure with a period of 200 nm was fabricated in a GaAs substrate by use of electron-beam lithography and dry-etching techniques. The form birefringence of this microstructure was studied numerically with rigorous coupled-wave analysis and compared with experimental measurements at a wavelength of 920 nm. The numerically predicted phase retardation of 163.3 degrees was found to be in close agreement with the experimentally measured result of 162.5 degrees, thereby verifying the validity of our numerical modeling. The fabricated microstructures show extremely large artificial anisotropy compared with that available in naturally birefringent materials and are useful for numerous polarization optics applications