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Due to their chemical and physical properties, rare earth elements (REEs) are essential in modern applications such as energy conversion or IT technology. The increasing demand for these elements leads to strong incentives for REE recovery and induces the exploration of new, alternative sources for REEs. Accessing REEs from clay minerals, in our case kaolinite, by an elution process is a promising method. The present study investigates the potential application of REE recovery through elution with different mineral acids (HNO3, H2SO4, and HCl) in a microwave process. The material used in this study—residues from an industrial kaolin production process—contained 2.47 g/kg REEs which is a significant amount for REE recovery. The ability of various mineral acids to solubilize metals was studied to assess the REE content of this residual resource. Around 1.87 g/kg of REEs was eluted from industrial kaolinite residues in hydrochloric acid, 1.71 g/kg in sulfuric acid, and 1.13 g/kg in nitric acid. [ABSTRACT FROM AUTHOR]

Elevated carbon dioxide (eCO2) and rising temperatures will have far‐reaching effects on global plant‐insect interactions, yet their implications for future biological control programs are not fully understood. Studies have shown that elevated CO2 will affect insect feeding guilds differently and these responses can be predicted with some confidence. Water hyacinth, Pontederia crassipes Mart. (Pontederiaceae), is a native and representative species of the Del Plata wetlands (Argentina) that invades outside of its native environment. It is considered one of the world's worst aquatic weeds and a target for biological control. In this study, water hyacinth plants were grown under two CO2 concentrations – current (400 p.p.m.) or elevated (800 p.p.m.) –, with and without two biocontrol agents representing different feeding guilds, the leaf‐chewing Cornops aquaticum Brüner (Orthoptera: Acrididae) and the phloem‐feeding Megamelus scutellaris Berg (Hemiptera: Delphacidae). Under eCO2 concentration, photosynthetic rate, total dry weight, and relative growth rate of P. crassipes acclimated to eCO2 conditions and plants showed very little CO2 fertilization response in eutrophic water. Insect herbivory varied depending on feeding guilds at eCO2; however, P. crassipes growth responses increased when exposed to insect herbivory. Chewing herbivory by C. aquaticum was consistent across CO2 conditions, whereas the feeding by M. scutellaris increased substantially at eCO2. These results indicate that successful biological control of P. crassipes under conditions of elevated CO2 might rely on phloem‐feeding insects, with chewers playing a lesser role. [ABSTRACT FROM AUTHOR]

Purpose: To assess the cross-sectional association between dietary indexes (DI) that underlie, respectively, the Nutri-score (NS), the proposed Canadian 'High In' Symbol (CHIL) and the Diabetes Canada Clinical Practice Guidelines (DCCP) with food consumption, nutrient intakes and metabolic markers. Methods: 1836 adults (18–74 years) participating in the representative ESTEBAN study, conducted in mainland France in 2014–2016, were included in the analysis. Food consumption was assessed with three repeated 24 h dietary recalls. Anthropometric measurements and biomarkers of metabolic risk (cholesterol—total, LDL (Low Density Lipoprotein), HDL (High Density Lipoprotein)—triglycerides, glucose) were obtained through a clinical examination and fasting blood draw. The DI were assessed for their association with food consumption, dietary intakes and metabolic biomarkers as quintiles and continuous variables using multi-adjusted linear regression. Heathier diets were assigned to lower scores. Results: Correlations between scores ranged from + 0.62 between CHIL-DI and NS-DI to + 0.75 between NS-DI and DCCP-DI. All DIs discriminated individuals according to the nutritional quality of their diets through food consumption and nutrient intakes (healthier diets were associated with lower intakes of energy, added sugars and saturated fat; and with higher intakes of fiber, vitamins and minerals). NS-DI was associated with blood glucose (adjusted mean in Q1 = 5 vs. Q5 = 5.46 mmol/dl, ptrend = 0.001) and DCCP-DI was associated with BMI (Q1 = 24.8 kg/m2 vs. Q5 = 25.8 kg/m2, ptrend = 0.025), while CHIL showed no significant association with any anthropometric measures or biomarkers. Conclusions: This study provides elements supporting the validity of the nutrient profiling systems underlying front-of-package nutrition labellings (FOPLs) to characterize the healthiness of diets. [ABSTRACT FROM AUTHOR]

Iron reduction and sulfate reduction often occur simultaneously in anoxic systems, and where that is the case, the molar ratio between the reactions (i.e., Fe/SO42− reduced) influences their impact on water quality and carbon storage. Previous research has shown that pH and the supply of electron donors and acceptors affect that ratio, but it is unclear how their influences compare and affect one another. This study examines impacts of pH and the supply of acetate, sulfate, and goethite on the ratio of iron to sulfate reduction in semi‐continuous sediment bioreactors. We examined which parameter had the greatest impact on that ratio and whether the parameter influences depended on the state of each other. Results show that pH had a greater influence than acetate supply on the ratio of iron to sulfate reduction, and that the impact of acetate supply on the ratio depended on pH. In acidic reactors (pH 6.0 media), the ratio of iron to sulfate reduction decreased from 3:1 to 2:1 as acetate supply increased (0–1 mM). In alkaline reactors (pH 7.5 media), iron and sulfate were reduced in equal proportions, regardless of acetate supply. Secondly, a comparison of experiments with and without sulfate shows that the extent of iron reduction was greater if sulfate reduction was occurring and that the effect was larger in alkaline reactors than acidic reactors. Thus, the influence of sulfate supply on iron reduction extent also depended on pH and suggests that iron reduction grows more dependent on sulfate reduction as pH increases. Our results compare well to trends in groundwater geochemistry and provide further evidence that pH is a major control on iron and sulfate reduction in systems with crystalline (oxyhydr)oxides. pH not only affects the ratio between the reactions but also the influences of other parameters on that ratio. [ABSTRACT FROM AUTHOR]

[Display omitted] • Some invasive plant species, like Pontederia crassipes , could be possibly affected by climate change. • Megamelus scutellaris is one of the most commonly used biocontrol agents for P. crassipes. • As other planthoppers, M. scutellaris is expected to host obligate mutualistic organisms, known as Yeast-like symbiotes (YLS). • YLS are first reported in M. scutellaris species and their numbers are positively correlated with their host's weight. • YLS numbers increased under elevated CO 2 , in heavier females. Water hyacinth, Pontederia crassipes , is a highly invasive plant native to South America and one of the most invasive aquatic plants in the world. For its control, the planthopper Megamelus scutellaris Berg (Hemiptera: Delphacidae), a phloem feeder also native to South America has been introduced to the USA and South Africa. Considering predicted climate change scenarios, understanding their impacts on biological control agents is crucial. An intriguing yet scarcely explored subject, is the effect of climatic changes on the obligate endosymbionts associated with sap-sucking feeders. Planthoppers establish an obligate relationship with yeast-like symbiotes (YLS), unicellular fungal microorganisms that play an important role in their development, providing missing nutrients in their diet. Considering that increased atmospheric CO 2 affects plant chemical composition, this might have a direct impact on their insect host and on their number of YLS. We evaluated the effect of two different CO 2 environments: current (cCO 2 − 400 ppm) and elevated (eCO 2 − 800 ppm) on the abundance of YLS (number of YLS cells/insect) of M. scutellaris , as well as the, age structure, sex, and weight of insects. Heavier females harbored more YLS under eCO 2 which underscores the importance of the interaction of CO 2 levels and insects' weight in shaping the abundance of YLS. Additionally, there was a significant increase in the total abundance of insects for instars III to V and adults under eCO 2 conditions. However, male number significantly exceeded that of females under both CO 2 conditions. Our results suggest a potential positive impact of eCO 2 on M. scutellaris populations, which could, in turn, enhance the control of P. crassipes. [ABSTRACT FROM AUTHOR]