This study hypothesized that the gut microbial populations, intestinal morphology, and cytokine production are differentially altered in 2 different pig breeds, namely, Chinese native Jinhua pigs and European Landrace pigs, after orally challenge with enterotoxigenic Escherichia coli (ETEC) K88. A total of 12 Jinhua pigs and 12 Landrace pigs were allocated to either the nonchallenged or the challenged groups (6 pigs per group). The challenged pigs were orally administered ETEC K88, and their nonchallenged counterparts were given sterile Luria-Bertani broth. Selected gut microbial populations, intestinal morphology, mRNA expression of tight junction proteins, and the levels of ileal cytokines and secretory immunoglobulin A (sIgA) production were measured in Jinhua and Landrace pigs. The results showed that the challenged Jinhua pigs exhibited a significantly (P < 0.05) lower incidence of diarrhea compared with their Landrace counterparts. The Escherichia coli (E.coli) population and the percentage of E. coli in the total bacteria population were increased in response to ETEC K88 challenge in both Jinhua and Landrace pigs. The challenged Landrace pigs shed more E. coli (P < 0.05) and had higher percentage of E. coli in the total bacteria population in the colon (P < 0.05) compared with their Jinhua counterparts. Both pig breeds tended to exhibit greater villous atrophy and crypt depth reduction in all of the intestinal segments with challenge. The expression of tight junction proteins decreased in response to ETEC K88 challenge in both pig breeds. The levels of the proinflammatory cytokines interferon (IFN)-γ, tumor necrosis factor-α, and IL-6 and the secretion of sIgA were positively altered whereas the levels of the anti-inflammatory cytokine IL-4 and transforming growth factor (TGF)-β were negatively altered by ETEC K88 challenge in both breeds. Jinhua pigs exhibited significantly higher levels of IFN-γ and TGF-β (P < 0.05) in the challenged group. Our findings provide valuable evidence to explain the differences in the intestinal physiology between Jinhua and Landrace pigs; that is, Jinhua pigs appeared to show better growth performance, a lower incidence of diarrhea, and a lower extent of immune activation in response to ETEC K88 challenge and a higher Lactobacillus population, a higher percentage of Lactobacillus in the total bacteria population, a higher ratio of Lactobacillus to E. coli, and higher levels of tight junction proteins with and without challenge.

The nature of isostructural transformations of a type-I Ba 8 Si 46 clathrate has been studied by in situ highpressure angle-dispersive x-ray powder diffraction using liquid He as pressure transmitting medium. The good quality of the diffraction data permitted refinement of structural and thermal parameters from Rietveld analysis. The results show that the first transition at 7 GPa is caused by the displacement of the Ba atoms in the Si 24 cages. The cause of the second transition at 15 GPa, characterized by a dramatic reduction of cell volume, is not as clear. Theoretical calculations predicted an electronic topological transition of Fermi surface at this pressure. Analysis of the anomalously large Si thermal parameters suggested a highly disordered Si framework. This disordering is probably static and may be due to the presence of Si vacancies. The latter hypothesis is supported by electronic calculations on model disordered systems.

White spot disease remains a constant threat to aquaculture worldwide. Hyperthermia has been shown to reduce mortality in white spot syndrome virus (WSSV)-infected shrimps, but the mechanism still remains unclear. In this study, we sought to identify host immune factors that contribute to inhibition of WSSV infection during hyperthermia. In WSSV-infected red swamp crayfish Procambarus clarkii (Girard) cultured at 24 ± 1 °C, transcriptional levels of the heat shock protein 70 (Hsp70) gene showed a modest, 2.2-fold increase in haemocytes following 48 h post-infection (hpi). In contrast, in WSSV-infected crayfish cultured at 32 ± 1 °C, Hsp70 gene expression showed a rapid, 19.5-fold induction by 4 hpi. This suggests that Hsp70 plays a positive regulatory role in resistance to WSSV infection during hyperthermia. Furthermore, total haemocyte counts (THC) and phenoloxidase (PO) activity were both significantly increased in WSSV-infected crayfish cultured at 32 ± 1 °C by 48 hpi. Both may be critical for crayfish survival in the late stages of WSSV infection. Collectively, the up-regulation of host protein Hsp70 expression and increase in THC and PO activity suggest that hyperthermia has immunomodulatory effect that enhanced the resistance of P. clarkii to WSSV infection.