Despite the suggestion that impulsivity plays a central role in the transfer from a recreational drug use to a substance use disorder, very few studies focused on neurobiological markers for addiction. This study aimed to identify volumetric alterations in a sample of patients with mild alcohol use disorder with a short history of alcohol use, compared with a control group, and also focused on its association with impulsivity levels. Most magnetic resonance imaging studies have focused on severe alcohol use disorder, formerly called alcohol-dependent patients, showing alcohol-related structural alterations and their association with alcohol use history variables but not with personality parameters like impulsivity. Our hypothesis is that our group of alcohol users may already display structural alterations especially in brain regions related to inhibitory control like medial-prefrontal regions, and that those structural alterations could be more associated to personality traits like impulsivity than to drug use variables. Our results clearly demonstrate that our population showed lower regional grey and white matter volumes in the medial-prefrontal and orbitofrontal cortices, as well as higher regional white matter volume in the ventral striatum and the internal capsule. Volumetric alterations were associated to the Barratt's impulsivity score: the more impulsive the subjects, the lower the medial-prefrontal cortex grey matter volume.

No abstract

Cover cropping is a farming practice that may improve C sequestration and soil fertility, but these effects can vary under different edaphoclimatic conditions. The effects of including a winter gramineous cover crop (CC) in continuous soybeans were evaluated in three long-term experiments (8 yr) on one coarse-textured soil and two finetextured soils in the Pampas region of Argentina. The impacts of CC on soil C sequestration, soil nutrient availability, soil organic C (SOC), and N contents of soil particle size fractions were also determined. The inclusion of CC only increased SOC stock by 3.1 Mg ha -1 in the coarse-textured soil (CTS). The labile C fraction in the 0-5-cm depth increased in both the CTS and the fine-textured soils (FTS) by 263% and 93%, respectively. Soil N also increased in the labile fraction by 119% and 112% when a CC was used in the CTS and FTS soils, respectively. Moreover, the inclusion of a CC decreased soil P availability in one experiment (4.9 kg ha -1 ) and increased soil manganese in two experiments (11 kg ha -1 on average). The inclusion of a gramineous CC in a soybean monoculture increased the C balance, particularly in coarse-textured soils. Considering that soil N was similarly affected, the C/N ratio was not impacted.

No abstract

No abstract