While low serotonergic activity is often associated with psychological disorders like depression, anxiety, mood and personality disorders, variations in serotonin also contribute to normal personality differences. Here we investigate the role of blood DNA methylation levels at individual CpG sites of two key serotonergic genes (serotonin receptor gene 1A, HTR1A; serotonin transporter gene, SLC6A4) in predicting personality of captive chimpanzees. We find associations between methylation at 9/48 CpG sites with four personality dimensions: Dominance, Reactivity/Dependability, Agreeableness and Openness. Directionality of effects were CpG location-dependent and confirmed a role of serotonergic methylation in reducing anxiety (Dominance) and aggression related personality (Reactivity/Undependability) while simultaneously promoting prosocial (Agreeableness) and exploratory personality (Openness). While early-life adversity has been shown to impact serotonergic methylation patterns in other species, here, atypical early social rearing experiences only had a modest impact on CpG methylation levels in this chimpanzee sample. While the precise environmental factors impacting serotonergic methylation in chimpanzees thus remain to be identified, our study suggests a role in shaping natural variation in animal personality. The results of this study offer a basis for future hypothesis driven testing in additional populations and species to better understand the impact of ecology and evolution on complex behavioral traits.

Considering future tasks in soil health, resources management and environmental protection, farmers are challenged to develop sustainable strategies for managing soil and land resources. In this study, the long-term sustainability of two fertilization strategies, - current, with synthetic fertilizers (SYN) vs conservative, with organic sources of nitrogen (organic amendments plus green manure with a legume - CONS) - was assessed in a processing tomato/durum wheat rotation. The EPIC model was used, validated with field data then run to simulate the management for 30 years under 3 current and future climates. Yield, soil organic carbon (SOC) stock change, nitrogen use efficiency (NUE), water use efficiency (WUE) and nitrate leaching were considered as sustainability indicators. Under all the future climate scenarios, tomato yield increased in CONS, remaining almost stable in SYN. Wheat yield increased both in CONS and SYN, but the average yield in CONS was considerably lower than in SYN. NUE and nitrate leaching followed the same trend, both decreasing in CONS, while WUE was higher in CONS compared to SYN. The effect of CONS on SOC was always positive. Thus, the alternative N fertilization strategy proposed can be a favorable option for maintaining soil health and a sustainable crop production.

Vitamin C is an essential enzyme cofactor and antioxidant with pleiotropic roles in human physiology. Circulating vitamin C concentrations are lower in people with diabetes mellitus suggesting a higher dietary requirement for the vitamin. We interrogated the NHANES 2017/2018 and EPIC-Norfolk datasets to compare vitamin C requirements between those with and without diabetes mellitus using dose-concentration relationships fitted with sigmoidal (four parameter logistic) curves. The NHANES cohort (n=2828 non-supplementing adults) comprised 488 (17%) participants with diabetes (self-reported or HbA1c ≥6.5%). The participants with diabetes had a lower vitamin C status (median [IQR]) than those without (38 [17, 52] µmol/L vs 44 [25, 61] µmol/L, p<0.0001), despite comparable dietary intakes between the two groups (51 [26, 93] mg/d vs 53 [24, 104] mg/d, p=0.5). Dose-concentration relationships indicated that the group without diabetes reached adequate vitamin C concentrations (50 µmol/L) with an intake of 81 (72, 93) mg/d, whilst the those with diabetes required an intake of 166 (126, NA) mg/d. In the EPIC-Norfolk cohort, comprising 20692 non-supplementing adults, 475 (2.3%) had self-reported diabetes at baseline. The EPIC cohort had lower a BMI than the NHANES cohort (26 [24, 28] kg/m2 vs 29 [25, 34] kg/m2, respectively). Correspondingly, the EPIC participants without diabetes required a lower vitamin C intake of 64 (63, 65) mg/d while those with diabetes required 129 (104, NA) mg/d to reach adequate circulating vitamin C status. C-reactive protein concentrations were strongly correlated with body weight and BMI and provided a surrogate biomarker for vitamin C requirements. In conclusion, people with diabetes have 1.4- to 1.6-fold higher requirements for vitamin C than those without diabetes. This corresponds to additional daily vitamin C intake requirements of ~30-40 mg for people with diabetes.