לוח שנה משולב

Most human motor behaviors, such as speech or a piano concerto, are not innately programmed but are learned through a gradual process of trial and error. Learning requires exploration and the evaluation of subsequent performance. How are these processes implemented in the brain, and how do they go awry in disease? Songbirds provide a powerful model system to address these questions. Before they develop mature songs, young songbirds ‘babble’—producing highly variable vocalizations that underlie a process of trial-and-error. To investigate the neural mechanisms underlying exploration during learning, I recorded and manipulated neural activity in the basal ganglia, thalamus, and motor cortex-like nuclei in singing juvenile birds. Though the thalamus is traditionally considered a relay between the basal ganglia and cortex, I found that the thalamus, and not its inputs from the BG, was required for vocal variability during babbling. Meanwhile, the BG were required for song learning over time. Currently, my lab is pursuing three specific aims to study precisely how the BG support song learning. First, we are combining neural recordings with acoustic biofeedback to understand how neurons encode how ‘good’ (or ‘bad’) the song sounds. Second, we are developing optogenetic techniques to manipulate the activity of specific neuron subtypes in freely moving, singing birds. Finally, we are developing novel technologies to massively expand the number of neurons we can record simultaneously in singing birds. Basal ganglia circuits in songbirds and humans are very similar, and our overarching goal is to discover basic functions in a tractable model system that may ultimately provide insights into BG diseases such as Parkinson’s, Huntington’s and dystonia.

Spin based properties, applications, and devices are commonly related to magnetic effects and to magnetic materials. However, we established that chiral organic molecules can act as spin filter for photoelectrons transmission, in electron transfer, and in electron transport. The new effect termed Chiral Induced Spin Selectivity (CISS) has interesting implications on the production of new type of spintronics devices and on electron transfer in biological systems.
Results from several recent experiments, demonstrating the CISS effect, will be presented as well as devices based upon.

Models for the origin of life and early evolution on Earth cannot rely on fossils as biological evolution proper does. Plausibility replaces evidence, and what is plausible or implausible depends on the reference chosen. Pioneered by Sol Spiegelman and Manfred Eigen in the nineteen seventieth, experimental and theoretical models for evolution under controlled conditions became available. Within the last forty years the origin-of-life puzzle was not solved but the models have reached such a degree of perfection that they give direct insight into the molecular mechanisms of Darwinian selection. Epigenetic mechanisms of inheritance being just another way of transmitting inheritable information can be incorporated straightforwardly. Molecular models are directly applied to evolution of viroids, viruses, and bacteria, and open questions like the role of contingency in evolution can be answered for these systems.
Shneior Lifson contributed one essential idea to primitive evolution – the selective advantage of systems that can make use of their degradation products or sequels in a way that might today be called recycling.
In the lecture the state of the art in modeling primitive evolution and selection on the basis of molecular biology, chemistry and physics will be review. We shall refer in particular to the present knowledge on the prerequisites for designing molecular replicators. Eventually, the current situation in collecting raw data on evolution and processing them in order to make them suitable for application will be discussed.