Anomalous Scattering of Low-lying Excitations in a Spin-1 Bose-Einstein Condensate

We present the simplest theory of perfect tunneling of an excitation in a Bose-Einstein condensate (BEC) through an impurity potential with an arbitrary shape in the low-momentum limit. That is for the transverse spin wave in the ferromagnetic phase of a spin-1 BEC. This mode obeys a Schr\"odinger-type equation; yet, effects of the potential on its transmission coefficient $T$ and on its scattering cross section $sigma$ vanish in that limit. The order parameter determines $T$, and the momentum $p$-dependence of $sigma$ exhibits a Rayleigh scattering type ($sigma propto p^{4}$). These properties are common between two types of Nambu-Goldstone modes: this spin wave and the Bogoliubov mode.Comment: 5 page

Survey of the stray dog population and the health education program on the prevention of dog bites and dog-acquired infections: a comparative study in Nepal and Okayama Prefecture, Japan.

We estimated the number of stray dogs in Kathmandu, Nepal, where human rabies cases still occur, and in Shimotsui, Okayama Prefecture, Japan. In Kathmandu, the stray dog density was 2,930 stray dogs/km2, and the ratio of stray dogs to humans was 1:4.7. In Shimotsui, the density was 225 stray dogs/km2, and the ratio was 1:5.2. Since the stray dog population in Nepal is very large, one of the measures used to prevent dog bites and dog-acquired infections such as rabies is an effort to capture stray dogs. Another such measure is an effort to decrease the availability of food for stray dogs. We also organized health education programs in both Nepal and Okayama Prefecture, Japan, which involved a course on the prevention of dog bites and subsequent infections. After each course, a questionnaire survey was conducted. The results suggest that the course participants understood these important preventive methods. In addition to the measures mentioned above and the routine vaccination of dogs, this health education course is recommended as a long-term preventive program</p