לוח שנה משולב

Magnetic resonance imaging (MRI) has undergone a significant expansion during the last two decades and to-date stands as one of the most prominent diagnostic modalities in use. This technique offers non-invasive and non-ionizing tool, capable of probing a wide range of materials, and providing a broad spectrum of contrasts via intricate manipulations of atomic nuclear magnetization. These properties, together with the introduction of new and improved hardware, have led to a gradual increase in the prevalence of MR imaging, and to the development of numerous new methods, which extend the capabilities of MRI beyond basic anatomical diagnosis. Examples include the study of various physiological functions, analyzing chemical / metabolic properties of materials and tissues, tracking dynamic processes, and more.
One of the major driving forces in contemporary MRI-research rests in the pursuit of new schemes for retrieving improved images, and using shorter acquisition times. A single distinct approach, however, underlies the majority of MR imaging, and is based on encoding and reading the image information in the frequency (k-space) domain. Recent reports by Prof. Lucio Frydman et al, have introduced a conceptually different approach for collecting MR spectra, which is based on a progressive SPatiotemporal-ENcoding (SPEN) of the magnetic spins in the sample. This novel approach enabled the ultrafast acquisition of multidimensional NMR spectra in a single-scan, thereby offering up to several orders of magnitude reduction in the corresponding scan time.
The work which will be presented in this lecture further investigated the potential of SPEN, within the context of MR imaging. This entailed several research avenues ranging from the design of various multidimensional imaging protocols, through the development of an image reconstruction algorithm based on super-resolution principles, and the subsequent application of these methods for in-vivo imaging in animals and humans. As will be demonstrated SPEN-based protocols are able to more optimally utilize the parameter space supported by MRI. This allows them to surpass conventional imaging methods when dealing with spatial field inhomogeneities, and in some cases provide the means to collect reliable information under conditions which were so far unsuitable for MR-based investigations.

The talk will focus on approaches used to engineer materials at the nanoscale for various applications in future technologies. In particular, the case of carbon nanostructures (e.g. nanotubes, graphene) will be used to highlight the challenges and progress. Various organized architectures of nanostructures can be fabricated using relatively simple processes and the work in attaining control on the directed assembly of these structures will be discussed. Some of these structures offer excellent opportunity to probe novel nanoscale behavior; however, when it comes to engineering such materials into precise architectures, challenges remain. We have pursued several applications for these materials, taking into account their multifunctional properties. Some of these promising applications of carbon nanomaterials and their hybrids will be reviewed from the perspective of what has been accomplished in recent years and what remains for the future. Our efforts on the strategies of growth and manipulation of nanomaterials and some of our recent successes in controllably fabricating heterogeneous and complex nanostructures will be highlighted.

There seem to be numerous defects of the eye that would be expected to interfere with vision. Examples are the upside down retinal image, the blind spot in each eye's visual field, non-uniform spatial and chromatic resolution, and blur and image shifts caused by eye saccades. In order to overcome such defects scientists have proposed a variety of compensation mechanisms. I will argue that such compensation mechanism not only face empirical difficulties, but they also suffer from a philosophical objection. They seem to require the existence of a "homunculus" in the brain that contemplates the picture-like output of the compensation mechanism. A new view of what "seeing" consists in is required.
The new view of seeing considers seeing as a particular way of actively exploring the environment. This "sensorimotor" approach is subtly different from the idea of "active vision" known today in cognitive or computer science. The sensorimotor approach explains how, despite the eye's imperfections and despite interruptions in the flow of sensory input, we can have the impression of seeing everything in the visual field in detail and continuously.
I shall show how the phenomenon of "inattentional blindness" (or "Looked but Failed to See") is expected from the new approach, and I shall examine the phenomenon of "change blindness" which arose as a prediction from the theory. Finally I examine the question of the photographic quality of vision: why we have the impression of seeing things all over the visual field, why everything seems simultaneously and continuously present, and why things seem to visually impose themselves upon us in a way quite different from how memory and imagining do. To explain these facts I shall invoke four objectively measurable aspects of visual interactions: richness, bodiliness, partial insubordinateness and grabbiness.