ALD21: Professor Priyamvada Natarajan, Astrophysicist

Professor Priyamvada Natarajan

Professor Priyamvada Natarajan is a theoretical astrophysicist at Yale University who has worked in a variety of fields such as gravitational lensing, galaxy formation and supermassive black holes. She developed a way to map dark matter using gravitational lensing, or the bending of light around galaxies. Her techniques for developing dark matter maps are now standard in cosmology.

She loved astronomy from a young age, eventually doing computations for the Nehru Planetarium, India, after she impressed the director with a program she had written to plot sky maps.

Natarajan got her PhD in 1998 from University of Cambridge, and was elected to a fellowship at Trinity College, the first woman in astrophysics to achieve this. During her graduate research, she wrote a paper predicting that supermassive black holes would create a “black hole wind”, blowing stellar material thousands of light years away. This gas would then accrete and form stars, resulting in galaxies and globular clusters that were short of dark matter. This theoretical prediction was later proven correct by a team of researchers at the National Radio Astronomy Observatory, Virginia, in 2019.

She became a professor at Yale University, where she explored the formation of bright quasars that are powered by huge black holes, but which were formed early in the history of the universe, at the same time that stars were beginning to form. She suggested a process to explain how these black holes may have formed, without an accretion of stellar material, via the “direct-collapse” of gas disks. This process is now considered to be one of the main ways in which black holes form.

In 2009, Natarajan became a fellow of the Royal Astronomical Society, received a Guggenheim Fellowship, and won India’s “Face of the Future” award. She received an India Empire NRI award for Achievement in the Sciences in 2011, and more recently, the University of Delhi gave her a lifetime honorary professorship. She is also active in supporting women in STEM, acting as Chairman for Yale’s Women Faculty Forum.

You can follow her work here:

Twitter: @sheerpriya

Further reading

ALD21 Podcasts: The Root of the Science, Anne Chisa

Anne Chisa

The Root of the Science, Anne Chisa

The Root of the Science Podcast airs every Monday. Host Anne Chisa, aka Anne with an E, interviews guests from around the world, highlighting the work of Africans in STEM and giving them the opportunity to tell their stories in their own voice, and to talk about their research or projects. Chisa finds out why they got into STEM (the ROOT of their science) and has in-depth conversations about their lives, both in and away from the science.

Recent episodes feature:

  • Sandiso Ngwenya, PhD student in chemistry, who describes her love of beauty, the stereotypes of what female scientists are supposed to look like and how women such as herself are changing that;
  • Tracy Vongai Mapfumo, a passion-driven entrepreneur, food innovator, crop scientist;
  • Dr Cosnet Lerato Rametse, a clinician scientist, MD & PhD candidate in immunology, and her passion for pathology; and,
  • Faith February, PhD mature student in oceanography at the University of Cape Town who is researching the effects of atmospheric aerosols on climate change.

You can follow her work here:

Twitter: @Annelinda_c and @RootofSciPod
Instagram: @rootofscipod

ALD21: Professor Dame Pratibha Gai, Materials Chemist and Electron Microscopist

Pratibha Gai

Professor Dame Pratibha Gai

Professor Dame Pratibha Gai co-invented the atomic resolution environmental transmission electron microscope (ETEM), which allows scientists to visualise and analyse gas-catalyst reactions at an atomic scale, leading to a better understanding of how catalysts work. 

Over two decades, Gai and her team redesigned a standard electron microscope. They drilled a hole through the imaging lens so that gas could be pumped into the electron microscope chamber, turning it into a chemical reaction vessel that could be used at high temperatures and pressures. 

Using the ETEM, Gai became the first person to see “columns of atoms” interacting in real time during a reaction. Before the ETEM, such high resolution microscopy could only be done before or after a chemical reaction had taken place – it wasn’t possible to watch the reaction happening. 

“I could see how a substrate interacted with a noble metal nanoparticle catalyst and watch the changing structure at atomic level,” she told Wiley Analytical Science Magazine. “It was thrilling.”

The newest version of the microscope is the environmental scanning transmission electron microscope (ESTEM), which allows scientists to see individual atoms undergoing chemical reactions. 

Gai uses the ESTEM to more fully understand chemical reactions and to develop catalysts for use in fields such as medicine and sustainable materials. She has developed antibiotic nanoparticles to control infection in medical implants, and an environmentally responsible nanocoating process for strong polymers and coatings.

Gai became a Dame Commander of the Order of the British Empire For services to Chemical Sciences and Technology in 2018, and a L’Oréal-UNESCO For Women in Science Awards Laureate for Europe in 2013. She’s also an honorary fellow of the Royal Academy of Engineering, the Royal Society, and the Royal Microscopical Society. 

Further reading

ALD21 Books: Rebel Cell, Dr Kat Arney

Dr Kat Arney

Rebel Cell: Cancer, Evolution and the Science of Life, Dr Kat Arney

Cancer has always been with us. It killed our hominid ancestors, the mammals they evolved from and the dinosaurs that trampled the ground before that. Tumours grow in pets, livestock and wild animals. Even tiny jelly-like Hydra – creatures that are little more than a tube full of water – can get cancer. Paradoxically, many of us think of cancer as a contemporary killer, a disease of our own making caused by our modern lifestyles. But that’s not true. Although it might be rare in many species, cancer is the enemy lurking within almost every living creature. Why? Because cancer is a bug in the system of life. We get cancer because we can’t not get it.

Cancer starts when cells revolt, throwing off their molecular shackles, and growing and dividing out of control in a shambolic mockery of normal life. This is why we can’t avoid cancer: because the very genes that drive it are essential for life itself. The revolution has raged, on and off, for millions of years. But it was only in the twentieth century that doctors and scientists made any significant progress in understanding and treating cancer, and it’s only in the past few decades that we’ve finally begun to kick the mob’s malignant arse. Now the game is changing. Scientists have infiltrated cancer’s cellular rebellion and are finally learning its secrets.

Geneticist and science writer Kat Arney takes the reader back to the dawn of life on planet earth right up to the present day to get to the heart of what cancer really is and how by better understanding it we might one day overcome it.

Order the book on here and your purchase will support a local independent bookshop of your choice!

You can follow her work here:

Twitter: @Kat_Arney

ALD21: Professor Vivian Wing-Wah Yam, 任詠華, Chemist

Vivian Wing-Wah Yam

Professor Vivian Wing-Wah Yam, 任詠華

Professor Vivian Wing-Wah Yam is a chemist whose work on brighter and more efficient organic light emitting diodes (OLEDs) has led to the development of more efficient displays for mobile phones and laptops. These OLEDs can be deposited on a variety of materials, including clear plastic and glass, leading to better car headlights and larger flat screen TVs.

Yam’s aim is to reduce the amount of energy used in lighting by developing much more efficient lights and displays. Her research focuses on creating new photoactive materials by combining metal atoms with organic molecules that can absorb or emit light at a range of wavelengths and efficiencies.

Photoactive materials with tunable absorption and emission colours and other properties may lead to the development of materials that can more efficiently store solar energy, improving photovoltaics and solar fuels, and improving OLED displays and white organic light-emitting diodes (WOLEDs) for solid state lighting.

Other uses for these photoactive materials include harvesting sunlight for the photocatalysis of water to produce hydrogen gas, sensing biological molecules such as the amyloids found in Alzheimer’s disease, or even developing new binary optical memory for digital data storage.

In 2001, she became the youngest member of the Chinese Academy of Sciences, and in 2011 she became a L’Oréal-UNESCO Awards for Women in Science laureate. This year, she was a recipient of the 2022 American Chemical Society (ACS) National Award, The Josef Michl ACS Award in Photochemistry.

She is currently working on developing OLEDs with cheaper, more abundant metals such as nickel. She’s also investigating organic resistive memory which relies on molecules that don’t conduct electricity at low voltages, but can conduct at high voltages thus creating a binary resistive memory.

You can follow her work here:

Twitter: @VivianYam1

Further reading