[Characterization of carbon and oxygen isotopes of plant on climate and plant physiology at the southeastern margin of Qinghai-Tibet Plateau, China]. / é’è—é«˜åŽŸä¸œå—ç¼˜æ¤ç‰©ç¢³æ°§åŒä½ç´ å¯¹æ°”å€™åŠæ¤ç‰©ç”Ÿç†çš„è¡¨å¾.

To investigate the correlation between carbon and oxygen isotope compositions of plant cellulose and climatic factors as well as plant physiological indices on the southeastern margin of the Qinghai-Tibet Plateau, we examined plant species in eight sampling sites with similar latitudes and different longitudes in this region. Through the characteristics of δ13C and δ18O values, fractionation values (Δ13C and Δ18O) in leaf cellulose, we discussed water use efficiency (WUE) and the environmental factors, the variation of carbon and oxygen isotopes in the southeastern margin of the Qinghai-Tibet Plateau with elevation and longitude, and revealed the indication degrees of isotopic signals to different environments and vegetation physiology. By using the semi-quantitative model of carbon and oxygen dual isotopes, we investigated the physiological adaptation mechanisms of plants to varying environmental conditions. The results demonstrated that both Δ13C and Δ18O of cellulose decreased with increasing elevation and longitude, and Δ13C was more influenced by longitude, while Δ18O was more susceptible to elevation variation. Additionally, Δ13C and Δ18O were significantly and positively correlated with temperature (TEM), precipitation (PRE), potential evapotranspiration (PET), and relative humidity (RH). PRE was the dominant meteorological factor driving the variation of Δ13C, while RH was the dominant meteorological factor influencing Δ18O variation. In contrast to Δ13C, WUE showed a stronger correlation with elevation than with longitude, which increased as elevation and longitude increased. According to the carbon-oxygen model, plant stomatal conductance (gs) and photosynthetic capacity (Amax) decreased with increasing precipitation and relative humidity, while the values increased with increasing elevation and longitude. The combined analysis of carbon and oxygen isotopes of organic matters would yield additional environmental and gas exchange information for studies on climate tracing and vegetation physiology studies on the southeastern margin of the Qinghai-Tibet Plateau.

Risk ranking of pathogens in ready-to-eat unprocessed foods of non-animal origin (FoNAO) in the EU: initial evaluation using outbreak data (2007-2011).

Foods of non-animal origin (FoNAO) are consumed in a variety of forms, being a major component of almost all meals. These food types have the potential to be associated with large outbreaks as seen in 2011 associated with VTEC O104. In order to identify and rank specific food/pathogen combinations most often linked to human cases originating from FoNAO in the EU, a semi-quantitative model was developed using seven criteria: strength of associations between food and pathogen based on the foodborne outbreak data from EU Zoonoses Monitoring (2007-2011), incidence of illness, burden of disease, dose-response relationship, consumption, prevalence of contamination and pathogen growth potential during shelf life. The top ranking food/pathogen combination was Salmonella spp. and leafy greens eaten raw followed by (in equal rank) Salmonella spp. and bulb and stem vegetables, Salmonella spp. and tomatoes, Salmonella spp. and melons, and pathogenic Escherichia coli and fresh pods, legumes or grains. Despite the inherent assumptions and limitations, this risk model is considered a tool for risk managers, as it allows ranking of food/pathogen combinations most often linked to foodborne human cases originating from FoNAO in the EU. Efforts to collect additional data even in the absence of reported outbreaks as well as to enhance the quality of the EU-specific data, which was used as input for all the model criteria, will allow the improvement of the model outputs. Furthermore, it is recommended that harmonised terminology be applied to the categorisation of foods collected for different reasons, e.g. monitoring, surveillance, outbreak investigation and consumption. In addition, to assist future microbiological risk assessments, consideration should be given to the collection of additional information on how food has been processed, stored and prepared as part of the above data collection exercises.

The risk of rinderpest re-introduction in post-eradication era.

In 2011, ten years after the last reported outbreak, the eradication of rinderpest was declared. However, as rinderpest virus stocks still exist, there remains a risk of rinderpest re-introduction. A semi-quantitative risk assessment was conducted to assess this risk, which was defined as the probability of at least one host becoming infected and infectious outside a laboratory anywhere in the world within a one-year period. Pathways leading to rinderpest re-introduction were: deliberate or accidental use of virus in laboratories, deliberate or accidental use of vaccines, host exposure to an environmental source of virus, and use of virus for anti-animal biological warfare. The probability of each pathway step occurring was estimated through expert opinion elicitation. The risk estimate was associated with a high degree of uncertainty. It was estimated to range from negligible to high, with the median being very low. The accidental use of laboratory virus stocks was the highest risk pathway. Reducing the number of virus stocks and restricting their use, as well as upgrading the laboratories to a higher biosafety level, would effectively decrease the maximum and median risks. Likewise, ensuring that remaining vaccine stocks are not used and are instead destroyed or relocated to a limited number of regional repositories would also have a major effect on these estimates. However, these measures are unlikely to eliminate the risk of rinderpest re-introduction so that maintaining response preparedness is essential.