ABSTRACT
Aim: The aim of this study was to test the effects of Korean floor-heating system on heat loss using adult pig models, and to create a novel formula for estimating time since death during the early stages of decomposition. Methodology: Three electric mattress pads were placed on the ground to maintain a constant temperature of the substrate like the ondol heating system. Four temperature measuring probes were placed in each pig: inside the rectum, on the body surface, between the body and the surface of mattress pad and on the mattress pad. The probes were connected to a temperature data logger system. Temperature was recorded every minute and statistical analysis was performed using the SAS (version 9.3) program. Results: Spearman's Rank Correlation results demonstrated the rectal temperature, and the temperature between the body and the surface of pad were strongly correlated with postmortem cooling of the body, rather than ambient temperature. The rate of cooling of the body is represented by a cube function of time rather than an exponential or bi-exponential function. Interpretation: This research indicates that postmortem cooling of the body is more influenced by ground surface temperature than by ambient (environment) temperature, and the rectal temperature fluctuated with the ambient temperature. Additionally, the study showed that pigs can be good animal models that can substitute human cadaver to study the process of decomposition
ABSTRACT
Three species of the pulmonate snails of the family Planorbidae have been reported from Korea; Gyraulus convexiusculus, Hippeutis (Helicorbis) cantori and Segmentina (Polypylis) hemisphaerula. Of these 3 species, only H. cantori is reported as the molluscan intermediate host of Neodiplostomum seoulensis, one of the important snail-borne human intestinal trematodes in Korea. However, S. hemisphaerula was also found to be an intermediate host for N. seoulensis. In field-collected snails, H. cantori and S. hemisphaerula were found shedding bifurcated cercariae of N. seoulensis, whereas no G. convexiusculus was found shedding cercariae. In experiments with laboratory-bred snails, only S. hemisphaerula was susceptible to miracidia of N. seoulensis. Tadpoles of Rana nigromaculata and R. rugosa were exposed to cercariae shed from field-collected and laboratory-bred S. hemisphaerula. All tadpoles of R. nigromaculata were found to be massively infected, but none of the tadpoles of R. rugosa were infected with larvae of N. seoulensis. Metacercariae from tadpoles of R. nigromaculata and the snake Rhabdophis tigrinus tigrinus were fed to rats, and eggs of N. seoulensis were detected in the rat feces one-week later. These rats were killed and adult N. seoulensis recovered from the small intestines. This is the first report of S. hemisphaerula as a molluscan intermediate host for N. seoulensis in Korea.