Plant defences mediate interactions between herbivory and the direct foliar uptake of atmospheric reactive nitrogen

Reactive nitrogen from human sources (e.g., nitrogen dioxide, NO2) is taken up by plant roots following deposition to soils, but can also be assimilated by leaves directly from the atmosphere. Leaf uptake should alter plant metabolism and overall nitrogen balance and indirectly influence plant consumers; however, these consequences remain poorly understood. Here we show that direct foliar assimilation of NO2 increases levels of nitrogen-based defensive metabolites in leaves and reduces herbivore consumption and growth. These results suggest that atmospheric reactive nitrogen could have cascading negative effects on communities of herbivorous insects. We further show that herbivory induces a decrease in foliar uptake, indicating that consumers could limit the ability of vegetation to act as a sink for nitrogen pollutants (e.g., smog from mobile emissions). Our study suggests that the interactions of foliar uptake, plant defence and herbivory could have significant implications for understanding the environmental consequences of reactive nitrogen

Contribution of Aflatoxin B1 Exposure to Liver Cirrhosis in Eastern Ethiopia: A Case-Control Study

Abraham Mekuria,1 Lei Xia,2 Tekabe Abdosh Ahmed,3 Solomon Bishaw,4 Zelalem Teklemariam,5 Teshome Nedi,1 Tefera Abula,1 Ephrem Engidawork,1 Yun Yun Gong2 1Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia; 2School of Food Science and Nutrition, University of Leeds, Leeds, UK; 3Department of Internal Medicine, School of Medicine, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia; 4Department of Radiology, School of Medicine, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia; 5School of Medical Laboratory Sciences, College of Health and Medical Sciences, Haramaya University, Harar, EthiopiaCorrespondence: Ephrem Engidawork; Yun Yun Gong, Email [email protected]; [email protected]: Liver cirrhosis is a global health problem due to a large number of disability-associated life years and mortality. However, evidence is scarce on its causes in Eastern-Ethiopia, a place where there is a high prevalence of liver cirrhosis of unknown etiology. This study attempted to identify the risk factors related to liver cirrhosis in the area.Methods: A case-control study was conducted at a tertiary care hospital from January 2020 to July 2021. Following diagnoses using an ultrasound-based cirrhosis scale, a total of 127 cases were identified and compared with 253 control patients. A structured questionnaire and data abstraction form were used to collect demographic, lifestyle, and clinical information. A blood sample was also taken from each participant for clinical chemistry, hepatitis B virus (HBV), and hepatitis C virus tests as well as for an aflatoxin B1 (AFB1) albumin adduct (AF-alb) assay. Binary logistic regression analysis was used to determine predictors of liver cirrhosis.Results: AF-alb levels were detected in 75% of the cases and 64% of the controls, with a median (IQR) level of 11 pg/mg (5.5– 25) and 7.0 pg/mg (4.3– 20.5), respectively (p< 0.05). Moreover, the number of subjects with high AF-alb levels (≥ 8.6 pg/mg) was greater in cases (45%, p< 0.05)) than controls (28%). Age ≥ 55 years (adjusted odds ratio (AOR)=0.4; 95% CI: 0.2, 0.8), being a farmer (AOR= 3.0; 95% CI: 1.5, 6.0), family history of liver disease (AOR= 2.9; 95% CI: 1.1, 7.9), HBV seropositivity (AOR=4.0; 95% CI: 1.9, 8.8), and exposure to high levels of AF-alb (AOR=2.0; 95% CI: 1.1, 3.7) were significantly associated with liver cirrhosis.Conclusion: This study found a strong link between AFB1 exposure and liver cirrhosis. Mitigation of aflatoxin exposure and a better understanding of additional environmental risk factors like pesticides may be necessary to reduce the disease burden in Ethiopia.Keywords: liver cirrhosis, aflatoxin, hepatitis B virus, Ethiopi

The full annual carbon balance of a subtropical coniferous plantation is highly sensitive to autumn precipitation

Abstract Deep understanding of the effects of precipitation on carbon budgets is essential to assess the carbon balance accurately and can help predict potential variation within the global change context. Therefore, we addressed this issue by analyzing twelve years (2003–2014) of observations of carbon fluxes and their corresponding temperature and precipitation data in a subtropical coniferous plantation at the Qianyanzhou (QYZ) site, southern China. During the observation years, this coniferous ecosystem experienced four cold springs whose effects on the carbon budgets were relatively clear based on previous studies. To unravel the effects of temperature and precipitation, the effects of autumn precipitation were examined by grouping the data into two pools based on whether the years experienced cold springs. The results indicated that precipitation in autumn can accelerate the gross primary productivity (GPP) of the following year. Meanwhile, divergent effects of precipitation on ecosystem respiration (Re) were found. Autumn precipitation was found to enhance Re in normal years but the same regulation was not found in the cold-spring years. These results suggested that for long-term predictions of carbon balance in global climate change projections, the effects of precipitation must be considered to better constrain the uncertainties associated with the estimation