Effectiveness of potato late blight (Phytophthora infestans) forecast by meteorological estimation in mountainous terrain based on CARAH rules.

Potato late blight (PLB) caused by Phytophthora infestans (Mont.) de Bary, its incidence and development are highly dependent on meteorological conditions. To solve the problem of PLB in mountainous terrain under the condition of limited meteorological monitoring capability, the air temperature and humidity was estimated based on the basic meteorological datasets, the forecast effect of the onset period and infection cycle of PLB based on CARAH rules was evaluated. The average MAE, RMSE and CI of the estimated air temperature and observations were 1.17 °C, 1.52 °C and 0.95, respectively. The average MAE, RMSE and CI of the estimated relative humidity and observations were 8.0 %, 10.7 % and 0.53, respectively. The curve of the infection cycle of PLB at different locations were estimated from the basic meteorological datasets based on the CARAH rules, and the false alarm and missing ratios were 8.8 % and 4.6 % respectively. It may be delayed by 1 or 2 fungal generations compared to the observations, and then the protective fungicide should be adjusted to a systemic fungicide. The false alarm of the infection cycle of PLB may increase in dry air conditions, and the missing report may occur in humid condition.

[Study of the role of nuclear factor-kappa B in preterm birth with subclinical chorioamnionitis].

OBJECTIVE: To investigate the role of nuclear factor-kappa B (NF-kappaB) in preterm birth with subclinical chorioamnionitis. METHODS: From October 2005 to October 2006, 111 cases including 36 cases of preterm birth in labor, 37 cases of full term gravida with spontaneous labor and 38 cases of full term gravida without threatened labor in the Hunan Province People's Hospital, third Xiangya Hospital of Central South University and Changsha Maternal and Child Care Service Center were enrolled in the study. After delivery, by pathology results of fetal membrane they were divided into two groups: subclinical chorioamnionitis group (subclinical infectious group) and non-infectious group. Immunohistochemical staining and RT-PCR were used to observe the change of the p65 subunit of NF-kappaB family in maternal blood and fetal membrane in subclinical infectious group and non-infectious group. RESULTS: (1) The incidence of subclinical chorioamnionitis: there were 24 cases of subclinical chorioamnionitis in the 36 cases of preterm birth in labor (67%), 7 cases in the 37 cases of full term gravida with spontaneous labor group (19%) and 3 cases in the 38 cases of full term gravida without threatened labor group (8%). There was a significant difference among the three groups (P < 0.01). In the totally 111 cases, 34 cases were classified as subclinical infectious group and 77 cases as non-infectious group. (2) In fetal membrane, the median of the average staining intensity of NF-kappaB p65 protein was higher in the subclinical chorioamnionitis group (8.0) than those in non-infectious group (4.0). Similarly, the average staining intensity of NF-kappaB p65 mRNA was higher in the subclinical infectious group (47.5 +/- 17.2) than those in non-infectious group (31.3 +/- 13.6). There was a significant difference between the two groups (P < 0.01). (3) In maternal blood, the expression of NF-kappaB p65 protein and mRNA was higher in subclinical chorioamnionitis group(8.0 and 42.6)than those in non-infectious group(4.0 and 23.6).There was a significant difference between the two groups (P < 0.01). (4) The concentration of NF-kappaB p65 protein in fetal membrane was positively correlated with that of maternal blood (r = 0.581, P < 0.01) and the concentration of NF-kappaB p65 mRNA in fetal membrane was positively correlated with that of maternal blood (r = 0.571, P < 0.01). CONCLUSION: The expression of NF-kappaB in maternal blood and fetal membrane in preterm birth with subclinical chorioamnionitis is higher and the two are correlated with each other. NF-kappaB p65 could be an accurate biochemical marker in predicting subclinical chorioamnionitis in preterm birth. NF-kappaB p65 plays an important role in the pathogenesis of subclinical chorioamnionitis in preterm birth.