Nucleation and growth of apatite on an anatase layer irradiated with UV light under different environmental conditions.

Implant surfaces must sometimes be modified to form strong bonds to host tissues. The method of depositing an anatase layer on chemically pure titanium by chemical oxidation with H(2)O(2) and subsequent calcination (CHT) is known to deposit apatite under physiological conditions; it thus exhibits bone-bonding ability. UV irradiation should affect the bonding ability because the CHT anatase layer would experience certain chemical modifications, such as a decrease or an increase in the number of Ti-OH and Ti-O(H)-Ti sites; these sites are considered active sites for apatite nucleation. When in vitro apatite deposition was examined, using Kokubo's simulated body fluid, UV irradiation in air reduced the apatite-forming ability of the CHT anatase layer, and UV irradiation on the samples in water enhanced the ability. These results were correlated to changes in the Ti-OH and Ti-O(H)-Ti sites, as determined by O 1s X-ray photoelectron spectroscopy. Analysis of the number and size of the semi-spherical apatite particles and their surface coverage led to a model: proper assembly of the Ti-OH and Ti-O(H)-Ti sites should only give rise to the induction of apatite nucleation, analogous to topotaxy effects.

Reproductive performance analysis of native pig smallholders in the hillside of northern Thailand.

We described the reproductive performance of native pigs raised by smallholders in a traditional way and used for ritual sacrifice in a Hmong village in the hills of northern Thailand. Field study was conducted between May 2005 and January 2007 (13 months in total). The pig reproductive performance in ten households during two years (January 2005 to December 2006) was as follows: The 15 farrowing samples in the households had an average litter size at birth of 7.1 and litter size at weaning of 6.0 (pre-weaning mortality 16%). A total of 107 piglets were born in the ten households during the two years, an average of 5.4 piglets per household per year. We were only able to collect data on farrowing intervals in three cases, two of eight months and one of 19 months. There was no concentrated farrowing period: of the 15 farrowings, there were seven months with one farrowing each (February, April, May, June, July, September, November), four with two farrowings (January, March, August, December), and one with none (October). This indicates that households have a variety of attitudes to pig reproduction, and that there is no seasonality in farrowing.

Decision-making on the use of diverse combinations of agricultural products and natural plants in pig feed: a case study of native pig smallholder in northern Thailand.

We have identified the feed offered to native pigs in a case study of smallholder in northern Thailand. We examined the types and fresh weights of pig feed over two 10-day periods in household A, in September 2006 (rainy season) and in December 2006 and January 2007 (dry season). The study results are as follows. (1) They offered 18 types of feed in total during the rainy and dry seasons, of which seven types were common to the rainy and dry seasons, five types were offered during the rainy season only, and six types during the dry season only. (2) They offered agricultural products as 34% of feed (rainy season) and 61% of feed (dry season), and natural plants used exclusively for pig feed as 66% of feed (rainy season) and 39% of feed (dry season). (3) The feed combinations at each feeding time differed 80% of the time during both the rainy and dry seasons. These results show not only that they offered diverse combinations of agricultural products and natural plants as pig feed, but also that they changed feed kinds in both the rainy and dry seasons.