The Calabi-Yau equation on the Kodaira-Thurston manifold, viewed as an S^1-bundle over a 3-torus

We prove that the Calabi-Yau equation on the Kodaira-Thurston manifold has a unique solution for every $S^1$-invariant initial datum.Comment: 17 pages. Final version, to appear in Journal of Differential Geometr

Is Soil Contributing to Climate Change Mitigation during Woody Encroachment? A Case Study on the Italian Alps

Background and Objectives: Over the last few decades, the European mountain environment has been characterized by the progressive abandonment of agro-pastoral activities and consequent forest expansion due to secondary succession. While woody encroachment is commonly considered as a climate change mitigation measure, studies suggest a still uncertain role of the soil organic carbon (SOC) pool in contributing to climate change mitigation during this process. Therefore, the objective of the study is to investigate the possible SOC variations occurring as a consequence of the secondary succession process at the provincial level in an Alpine area in Italy. Materials and Methods: A chronosequence approach was applied to identify, in five different study areas of the Belluno province, the land use/land cover change over four different stages of natural succession, from managed grazing land to secondary forest developed on abandoned grazing land. In each chronosequence stage, soil samples were collected down to the bedrock (0–60 cm depth) to determine the changes in the SOC stock due to the woody encroachment process. Results: In all areas, small or no significant (p < 0.05) SOC stock changes were observed during the secondary succession in the upper 30 cm of mineral soil, while significant changes were evident in the 30–60 cm compartment, with the SOC stock significantly decreasing from 30% to 60% in the final stage of the succession. This fact indicates the great importance of considering also the subsoil when dealing with land use/land cover change dynamics. Conclusions: The recorded trend in SOC has been proved to be the opposite in other Italian regions, so our results indicate the importance of local observation and data collection to correctly evaluate the soil contribution to climate change mitigation during woody encroachment

Innovación tecnológica en predicción de tormentas electrica

IP 1101-452-21191El presente informe contiene la descripción de las actividades realizadas durante los 24 mese de ejecución del proyecto. La primera etapa se centro en el acondicionamiento de la red de medida de campo electrostatico para lo cual se construyeron e instalaron sistemas de adquisición de datos capaces de conectarse a través de Internet con un servidor central localizado de las sede Bogotá de la universidad nacional