New research in structured light will have exciting outcomes for telecoms and other industries.
Professor Andrew Forbes is researching how to pack information into light, transmit it over distance and then unpack the information on the other side. He works with a vibrant team in the new Structured Light Laboratory that he established at Wits.
“We do this in both optical fibres and free space and at the classical and quantum levels,” explains Forbes, who took up his Distinguished Professorship in the Wits School of Physics in March 2015. “The aim of our research is to increase traditional bandwidth by at least two orders of magnitude (100 times) and to improve security between remote sites.”
The outcomes would be of interest to the telecoms industry, banks and the military. Light patterning can also be used to image complex structures such as nanostructures for drug delivery.
The achievement of these goals requires input from some of the best minds in physics when you consider that the diameter of an optical fibre is one-tenth the diameter of a human hair.
Enter Forbes, who worked on South Africa’s largest laser project years ago – uranium enrichment. In 2005, he joined the Council for Scientific and Industrial Research’s (CSIR) National Laser Centre, where he established a new research area in structured light (how to pattern light for a range of applications).
“This got me interested in laser beam propagation and the control of light,” he explains. “It was a small step from here to laser beam shaping.”
He explains that the challenge of using patterns of light to transmit information is that you need to be able to create patterns that can travel – and even accelerate – over long distances. You also need to be able to decode them. “Every time you see the light structure that looks like a particular petal shape pattern, that’s the letter ‘A’; another pattern will be the letter ‘B’, and so on. It’s essentially sophisticated Morse code.”
Forbes and his team design the patterns by using digital holograms and are working on designing the most efficient mode of patterning, and on refining the transmission process. They also need to ensure that the information is secure and encrypted – it’s called quantum cryptography.
In addition to its communication potential, light patterning can also be used to image complex structures such as nanostructures for drug delivery.
“To build more complex nanostructures you need to be able to see them so that you can move them around,” he explains. “Our ability to image these complex structures and to use light as a tool to move them around would significantly contribute to the advancement of nanostructures.”
He concludes: “I would like to patent and licence our work for start-up companies. This is what Africa needs – to start with good people and excellence in science and then to make an economic impact by leveraging on this.”
One step closer
- By Wits University
The development of a vaccine remains the best possibility for ending the HIV pandemic.
A PhD student from the University of the Witwatersrand today, 12 October 2015, published a study in the prestigious journal, Nature Medicine, describing how the changing viral swarm in an HIV infected person can drive the generation of antibodies able to neutralize HIV strains from across the world. The study has important implications for the design of a protective HIV vaccine.
Jinal Bhiman, a PhD student in the Faculty of Health Sciences is the lead author of the study, titled: Viral variants that initiate and drive maturation of V1V2-directed HIV-1 broadly neutralizing antibodies.
Challenge
The development of a vaccine remains the best possibility for ending the HIV pandemic. However, the researchers say that a major challenge has been the inability to stimulate broadly neutralizing antibodies that are able to deal with the enormous variability of HIV.
While some infected people are naturally able to make broadly neutralizing antibodies, these antibodies often have unusual features, and generally need to go through an extensive maturation process in order to acquire breadth. Studying these rare people to understand how such antibodies develop provides a roadmap for vaccine strategies.
Multiple approaches
Through a variety of “high tech” approaches, including the isolation of monoclonal antibodies from single B cells and ultra-deep sequencing of shifting viral populations over more than three years of infection, the researchers studied one woman who developed potent broadly neutralizing antibodies.
The team, led by Professors Penny Moore and Lynn Morris, was able to look back in time to identify the unique virus that bound the precursors of what would become broadly neutralizing antibodies, beginning the immune pathway to breadth.
“The study also showed how these early antibodies matured to become broadly neutralizing. As the HIV-swarm struggled to evade these potent early antibodies, it toggled through many mutations in its surface protein. This exposed the maturing antibodies to a diverse range of viruses within this single infected woman,” the researchers say.
“Antibodies exposed to this high level of viral diversity in turn mutated to be able to tolerate variation, thus acquiring the ability to neutralize diverse global viruses.”
Findings
These findings provide insights for the design of vaccines that can “kick-start” and then shape the maturation of broadly neutralizing antibodies in HIV uninfected individuals, to provide protection from HIV exposure.
The study was performed at the National Institute for Communicable Diseases of the National Health Laboratory Service, as part of the Centre for the AIDS Programme of Research in South Africa consortium, with long-standing collaborations with the University of Cape Town, the US National Institutes for Health Vaccine Research Center and Columbia University.
This research was funded by the South African Department of Science and Technology, the SA Medical Research Council Strategic Health Innovations Programme, the US National Institutes of Health and the Wellcome Trust.
Prehistoric Tarzan-like ancestor
- By Wits University
The two papers, titled: The foot of Homo naledi and The hand of Homo naledi, describe the structure and function of the H. naledi hand and foot.
The second set of papers related to the remarkable discovery of Homo naledi, a new species of human relative, show that Homo naledi had unique Tarzan-features – climbing trees as well as walking upright.
The two papers, titled: The foot of Homo naledi and The hand of Homo naledi, describe the structure and function of the H. naledi hand and foot.
Taken together, the findings indicate H. naledi may have been uniquely adapted for both tree climbing and walking as dominant forms of movement, while also being capable of precise manual manipulation.
