Fusion reactions with the one-neutron halo nucleus (15)C.

The structure of (15)C, with an s(1/2) neutron weakly bound to a closed-neutron shell nucleus (14)C, makes it a prime candidate for a one-neutron halo nucleus. We have for the first time studied the cross section for the fusion-fission reaction (15)C+(232)Th at energies in the vicinity of the Coulomb barrier and compared it to the yield of the neighboring (14)C+(232)Th system measured in the same experiment. At sub-barrier energies, an enhancement of the fusion yield by factors of 2-5 was observed for (15)C, while the cross sections for (14)C match the trends measured for (12,13)C.

Oral vaccination against swine erysipelas--field experiences in Croatia.

In order to prove the effects of mass application of oral erysipelas vaccine via drinking water, in a farrow-to-finish production unit in Croatia, the growing-finishing animals were divided into 3 groups and treated as follows:--Group 1 (n=199) was vaccinated intramuscularly against swine erysipelas at 1 week and 3 weeks after arrival in the growing-finishing facility with a swine erysipelas bacterin.--Group 2 (n=199) were vaccinated at the same time with an avirulent culture of Erysipelothrix rhusiopathiae oral vaccine through drinking water.--Group 3 (n=200) was not vaccinated. Animals with clinical signs of swine erysipelas, chronic progressive arthritis at slaughter, mortality, average daily weight gain during the growing-finishing phase were evaluated. None of the pigs in the groups 1 and 2 showed clinical signs typical for acute swine erysipelas. Twenty-four of the pigs (12 %) in group 3 had pyrexia and skin lesions typical for swine erysipelas. Fifteen pigs in group 1, 13 pigs in group 2, and 63 pigs in group 3 had chronic progressive arthritis (group 1 and 2 vs. group 3: P < 0.01). No significant differences in mortality were recorded between the groups. Group 1 and 2 had higher (P < 0.05) average daily weight gains compared with the group 3.

The effect of a homologous bacterin given to sows prefarrowing on the development of Glässer's disease in postweaning pigs after i.v. challenge with Haemophilus parasuis serotype 5.

UNLABELLED: The trial was carried out to evaluate the impact of maternal antibodies on the development of Glässer's disease after i.v. exposure of weaned pigs with a homologous serovar of Haemophilus parasuis (HPS). Two groups of weaned pigs were formed. Group one VI (n = 10): born to vaccinated sows, weaners i.v. challenged one week postweaning and euthanatized 14 days postweaning. Group two NVI (n = 10 wearners): born to non vaccinated sows, i.v. challenged one week postweaning euthanatized 14 days postweaning. One week postweaning all weaners were i.v. inoculated with HPS serovar 5. The following parameters were evaluated: clinical signs (depression, centralnervous signs, fever, lameness), macroscopic lung, pleura, peritoneum, liver and joint changes, and mortality. All trial sows were HPS seronegative prior to vaccination. The HPS vaccinated sows were proven seropositive on day 3 p.p. (values > 0.24), the non vaccinated ones were tested seronegative (values < 0.23). The progeny of sows vaccinated prefarrowing with two doses of HPS serovar 5 bacterin were partially protected against HPS caused clinical and pathological signs. The majority of clinical signs as fever, depression, recumbency, lack of response to verbal stimuli and lameness showed significant (P < 0.05) milder clinical symptoms in VI than in NVI animals. Respiratory signs (P = .169) and involvement of the central nervous system as ataxia, muscular tremor, incoordination of hind legs and convulsions (P = 1) showed no significant differences between the groups. Except lesions of pericard (VI vs. NVI, P = .14) and pleura (VI vs. NVI, P = .14) there were significant (P < 0.05) macroscopic differences at necropsy in lung, liver, joints and cerebrospinal fluid between the offspring of vaccinated sows and the ones of non vaccinated dams. No HPS were isolated from the nasal mucosa of the pigs prior to inoculation. HPS serovar 5 was recovered at necropsy from the nasal mucosa of all pigs in both groups. One pig from group VI presented in all examined organs the presence of HPS serovar 5. The remaining animals in group VI revealed in lung, pericard, pleura, liver, joints and cerebrospinal fluid no presence of HPS. The rate of isolation between VI and NVI groups revealed a significant (P < 0.05) difference. All the survived piglets of group NVI showed positive ELISA titres against HPS serovar 5 (values > .24). The piglets that died or were euthanatized before the end of the study have not been subjected to ELISA serological testing. One piglet died in group VI before the end of the study. Non of the remaining animals in group VI showed seroconversion to HPS serovar 5. IMPLICATIONS: Vaccination of sows did not influence the colonisation of nasal mucosa, but progeny of sows vaccinated prefarrowing with two doses of HPS serovar 5 bacterin were partially protected against HPS caused diseases.