The origin of Galactic cosmic-ray ions has remained an enigma for almost a century. Although it has generally been thought that they are accelerated in the shock waves associated with powerful supernova explosions—for which there have been recent claims of evidence—the mystery is far from resolved. Cosmic rays, which are mostly protons, but also other ions and electrons, permeate our Galaxy and rain down on earth continuously, night and day. Although cosmic rays were discovered almost a century ago, back in the balloon age, their origins remain unclear even now. Almost no effort has been spared in pursuing this long-standing mystery: satellites, rockets and balloons have been launched, and enormous detector arrays have been installed on the ground and even under mountains and seas. I will give a historical overview of the search for the mysterious origin of cosmic rays and a report on the current status.
Cells reside and operate in a complex and dynamic extra-cellular matrix. The mechanical, structural and chemical properties of the matrix regulate a variety of cellular functions including signaling, adhesion, migration as well as invasion and metastasis in tumor systems. Unfortunately cell-matrix interactions have traditionally been studied in the context of artificial 2D environments, which are far from in vivo conditions. As a result, our understanding of the complex interactions at the cell-matrix interface has been quite limited. In particular, the mechano-chemical effects of the matrix, the proteolytic pathways and surface receptor dynamics on a 3D surface that are critical in invasion and tumor metastasis, and can not be fully studied in a 2D environment. In order to overcome the limited powers of observation in 2D, we utilize a combination of high resolution and high throughput confocal microscopy, bulk and micro-rheological measurements and multi-scale simulations rooted in statistical and continuum mechanics. Using an interdisciplinary approach allows us to understand and quantify the mechanical and chemical roles of the matrix in regulating signaling, adhesion and motility. Our results demonstrate that both cell structure and cell function are strikingly different in 3D than in 2D and that cellular response to minor mechanical changes in its extra-cellular environment is amplified in 3D than in 2D environments. Our experimental results are complemented by multi-scale simulations, that probe the physical foundations of cell-matrix interactions from the nano to the macro level. Our hybrid approach, combining high-resolution experimental and computational techniques demonstrates how a balance of cellular parameters (e.g. integrin expression and MMP activity) co-operate with matrix properties (e.g. composition, stiffness and porosity) to regulate adhesion, invasion and motility of tumor cells in native like environments.
Biomaterials are defined as materials that are used in medical devices or are in contact with biological systems. Their application can range from skeletal systems (bone implants, knee joints, dental implants etc), cardiovascular systems (stents, catheter, heart valve etc), organs (artificial kidney, heart lung machine, skin etc) and senses (contact lens, corneal bandage etc). The field of biomaterials uses ideas from medicine, biology, physics, chemistry, materials sciences, engineering, ethics, law and health care. Biomaterials are usually integrated into devices or implants hence the interdisciplinary aspect is important for progress. The field brings together researchers from diverse academic backgrounds. They must communicate clearly. Some disciplines that intersect in the development, study and application of biomaterials include: bioengineer, chemist, chemical engineer, electrical engineer, mechanical engineer, materials scientist, biologist, microbiologist, physician, veterinarian, ethicist, nurse, lawyer, regulatory specialist and venture capitalist. Biomaterials can be metals, ceramics, polymers, glasses, carbons, and composite materials. Such materials are used as molded or machined parts, coatings, fibers, films, foams and fabrics. One of the major applications of biomaterials is in the field of tissue engineering. This field combines the knowledge of engineering, life sciences and clinical practice to solve the problem of tissue loss or damage, aimed at facilitating the regeneration of damaged or diseased tissue. The essence of tissue engineering is the use of living cells, together with degradable scaffolds and growth factors in development of implantable parts or devices for the restoration of body function. A major component in the revolutionary field of tissue engineering is the development of the suitable scaffold for seeding cells, growth factors and subsequent growth of tissues. There has been a considerable effort devoted to improving material and biological properties of scaffolds used in bone tissue engineering during the past decade. We developed and investigated different porous scaffolds with improved material properties and biological functions. An introduction to various scaffold materials developed in the lab along with future challenges will be presented towards the end.
Nuclear magnetic resonance (NMR) is a technique that exploits the spin of certain nuclei to obtain a tell-tale signatures of the molecule. This technique finds immense use in diagnostic imaging of human tissue. We will explore the origins of the NMR effect. In addition to its medical uses, we will also address other novel and esoteric applications, such as quantum computing, low-field NMR, explosives detection, polymer and foodstuff characterization, single-cell and nanoparticle MRI.
In his address, the speaker Prof. Dr. Pervez Hoodbhoy aptly explained the four greatest ideas in physics: relativity, quantum mechanics, electro-weak unification and the string theory. These ideas had changed the very face of twentieth century physics and taken mankind into more exciting nooks and corners of the known and the unknown universes. The content of the lecture was aimed for the lay masses, and therefore commanded a lot of eager interest from people of all backgrounds. The lecture was followed by an active question and answer session, lasting another thirty minutes.
Studies of the DNA sequence are paving the ways to diagnose diseases at much early stages leading to possible cures of cancer. Presence of mutated genes could be considered a risk for undesired production of proteins resulting in diseases like cancer. This seminar will highlight the biology of the microarrays, different classification techniques to diagnose cancer and the necessary tools to increase the accuracy of diagnosis.