Integrated Calendar

Evolution acts on individual variation. Complex biological systems, such as colonies of social insects, are aggregates of multiple agents working together towards collective, higher-order goals, producing emergent collective properties on which natural selection acts. There is no central control dictating the activities of members in the assembly. Instead, agents use local signals that determine their behavior and are received through an intricate interaction network resulting in collective phenotypes. I examine how individual variation among workers in harvester ant colonies affects the collective behavior of the colony, producing individual variation among colonies. I will present work on how the structure of the interaction network among ant workers affects the foraging regulation of colonies of the red harvester ant, Pogonmyrmex barbatus. In addition, I will discuss the causes and consequences of individual variation in the collective behavior of colonies of the black harvester ant, Messor andrei. In both cases, variation at small local scales translates into variation at the system level, creating a behaviorally diverse population.

In recent years, technical and methodological advances concerning medical applications of magnetic resonance (MR) have allowed the acquisition of multiple types of data, beyond pure anatomy, in a single examination, including diffusion imaging, MR spectroscopy, perfusion, permeability imaging and functional MRI. Integrating the various MR methods along with multiparametric analysis, can improve patient evaluation, quantitative tissue classification and characterization, as well as therapy response assessment.
Accurate measurements of brain structures and lesion volumes can be performed using manual or semi-manual methods. Analysis of multiparametric data, including advanced imaging methods, requires the use of advanced analysis tools. Multiparametric analysis of MRI data includes supervised and un-supervised methods, and provides information that often requires validation.
In this talk, I will present state of the art methods used in MRI data acquisition and analysis for quantitative assessment and follow-up of brain lesions; give a brief description of the main methods used for advanced and multi-parametric image analysis; highlight controversial issues regarding the use and analysis of these methods and their potential use in clinical practice.