ALD22: Professor Janaki Ammal, Botanist and Cytologist

Janaki Ammal

Prof Janaki Ammal

Prof Janaki Ammal was born in 1897 in Kerala, India. She completed her undergraduate study at Queen Mary’s College, Chennai, and an honours degree from Presidency College before going to the USA to earn her master’s degree in botany in 1926, and a few years later her doctorate, from the University of Michigan.

After spending two years as a professor at the Maharaja’s College of Science in Trivandrum, she joined the Sugarcane Breeding Institute in Coimbatore. Her research focused on improving native Indian sugarcane species, which was not as sweet as the Saccharum officinarum plants the country was importing from Java. By cross-breeding dozens of plants to create hybrids in her laboratory, she developed a strain that yielded more sucrose and would grow well in tropical Indian conditions.

Unfortunately, as a single woman from a caste considered low, Ammal faced prejudice from her male colleagues, and she returned to the UK in 1940. She worked with Cyril Dean Darlington at the John Innes Institute and, over the course of five years, they wrote the Chromosome Atlas of Cultivated Plants, which records the chromosome number of around 100,000 plants and which is still a core text for modern plant scientists.

In 1946, Ammal joined the Royal Horticultural Society in Wisley as a cytologist, studying the structure and function of cells, and their first salaried female staff member. There, she studied the chromosomes of a wide number of garden plant species to better understand their evolution and varieties. She was particularly interested in magnolia, and several of her shrubs still survive at Wisley today.

She treated some magnolia seeds with a solution of colchicine, a drug usually used to treat gout, which resulted in the seedlings doubling the number of their chromosomes. The seedlings grew faster, showed variations in their leaf texture and developed longer-lasting flowers. One of her varieties, which has white petals and purple stamens, is named Magnolia kobus ‘Janaki Ammal’.

After World War II, she returned to India to become the first director of the Central Botanical Laboratory at Allahabad and manage the Botanical Survey of India, which had been established in 1890 to collect and catalogue India’s flora.

India had suffered some widespread famines in the 1940 during which millions died, and the Indian government was deforesting vast swathes of land, much to Ammal’s distress. She became much more active in working to protect India’s flora, in particular trying to ensure that Indian scientists had access to specimens collected from their own country. She was also instrumental in stopping a hydroelectric dam that would have flooded the botanically diverse Silent Valley. She headed a chromosomal survey of the Valley’s plants, and eventually the government shelved the project.

The Indian government awarded her the Padma Shri, the country’s fourth-highest civilian award, in 1977. In 1999, two awards were named after her: The EK Janaki Ammal National Award on Plant Taxonomy and EK Janaki Ammal National Award on Animal Taxonomy. And in 2019, a rose was named after her.

Further Reading

ALD22: Professor Fumiko Yonezawa, Theoretical Physicist

Fumiko Yonezawa

Professor Fumiko Yonezawa

Born in 1938, Fumiko Yonezawa, 米沢 富美子, was a theoretical physicist who studied amorphous materials, semiconductors and liquid metals.

Her career began when she studied amorphous materials, or glasses, as part of her doctorate at Kyoto University in the mid-1960s. She developed the Coherent Potential Approximation (CPA), a method for calculating physical characteristics, such as density or resistivity, of amorphous materials.

Later, at Keio University, Yonezawa and her team studied how, at an atomic level, liquids become crystals or amorphous solids, using computational models. She spent some time at City College of New York, returning to Japan in 1981. In the 1990s, she developed a “theory of metal-insulator transition in liquid selenium” and became interested in neural networks.

In 1984, she was awarded the Saruhashi Prize, which is awarded to Japanese women for research in the natural sciences, for her “Theory of Fundamental Physical Properties of Amorphous Materials”. She was the first woman to become President of the Physics Society of Japan in 1996 and, in 2005, she won a L’Oréal-UNESCO Award for Women in Science for “pioneering theory and computer simulations on amorphous semiconductors and liquid metals.”

In 2020, the Physical Society of Japan launched the Fumiko Yonezawa Memorial Award to “honor and encourage” female members of the society, presenting awards to five women in physics in Japan.

Fumiko Yonezawa died on 17 January 2019, aged 80.

Further Reading

ALD22: Professor Jewel Plummer Cobb, Cell Biologist and Cancer Researcher

Jewel Plummer Cobb

Professor Jewel Plummer Cobb

Jewel Plummer Cobb was a biologist who discovered how skin cells produce melanin and how they become cancerous. She also discovered that methotrexate was an effective treatment for some skin and lung cancers and childhood leukaemia.

Born in 1924 in Chicago, Cobb graduated from Talladega College in Alabama with a degree in biology in 1944, earning her master’s and then her doctorate in cell physiology from New York University. Her research focused on understanding how skin cells produce melanin and how those cells become cancerous. Her doctoral thesis, Mechanisms of Pigment Formation, examined the enzyme tyrosinase, which is required for skin cells to produce melanin, which is what causes colour in human skin.

After finishing her PhD, she spent two years at the Harlem Hospital Cancer Research Center where she developed a deep understanding of how to culture human tissue directly from a sample taken from a person. Few people understood these techniques in the 1950s. She became skilled at culturing cancer cells taken from patient biopsies and used these cultures to study the effect of various chemotherapy drugs on the cells’ morphology, migration and growth.

In 1952, she started her own laboratory which was the first tissue culture-based lab at the University of Illinois Medical School. She combined her early research on skin pigmentation and melanin with her newer work on cancer.

Two years later, she moved her lab back to Harlem, and began working with Jane Wright to study the effect that chemotherapy drugs had on melanoma, a type of skin cancer. Wright worked with the patients, and Cobb worked with cells cultured from the patients’ samples. They realised that Cobb’s results could help predict which treatments would work for each patient and type of cancer. Cobb used non-cancerous tissue samples as controls, something which wasn’t common practice at the time because it was so hard to culture non-cancerous cells.

In the early 1960s, Cobb and Wright showed that methotrexate was effective for treating several cancers, including skin and lung cancer, and childhood leukaemia. Cobb also worked with mice that had been bred to be more susceptible to skin cancer, and discovered that cells with more melanin were protected from damage caused by exposure to radium and X-rays. This was the first evidence that melanin protects cells from UVA/UVB light.

In 1969, Cobb became the first black dean at Connecticut College, where she began programs to encourage women and people of colour to study STEM and explore STEM careers. She later became the first black woman to be appointed to the National Science Board, which supervises the National Science Foundation.

Cobb died in 2017, aged 92.

Further Reading

ALD22: Professor Lise Meitner, Nuclear Physicist

Lise Meitner

Professor Lise Meitner

Professor Elise ‘Lise’ Meitner was a physicist who discovered the element protactinium and developed a theory of nuclear fission.

Lise Meitner was born in 1878. Fascinated by science and mathematics from an early age, her educational opportunities were severely limited because of her sex, and she had to take private lessons so that she could sit her exams. In 1905, she became only the second woman to earn a doctorate in physics from the University of Vienna.

After initially studying optics, she moved on to radioactivity which was, at that point, a new field of study. She discovered that when a beam of alpha particles was fired at metal foil, its scattering would increase with the increased atomic mass of the metal atoms. Ernest Rutherford used the results of this experiment to then predict the nuclear atom.

Meitner was unusual in being allowed to attend Max Planck’s lectures, as Planck generally rejected the idea that women should be allowed to get an education but he recognised her as an exception. At this time, she was introduced to Otto Hahn, a chemist, with whom she began a lifelong collaboration. They developed a new way to detect isotopes and tests soon resulted in the discovery of two new isotopes. Meitner then began studying beta radiation.

Hahn and Meitner moved to the Kaiser Wilhelm Institute (KWI) for Chemistry, in 1912, where he became a professor whilst her position was as an unpaid ‘guest’. But later that year Plank employed her as an assistant, making her the first female scientific assistant in Prussia. She soon got promotion to associate, though, and later an increased salary to persuade her not to move to Prague.

With the outbreak of World War I, Meitner trained and then worked as an x-ray nurse-technician. She was discharged in 1916.

The next year, she was given her own lab at KWI, where she started to search for the ‘mother isotope’ of actinium. As the men at the institute had been called up, she did much of the work herself and discovered the first long-lived isotope of protactinium, for which she was awarded the Leibniz Medal.

At the beginning of World War II, when Austria was annexed by Germany, Meitner fled to Sweden. She and Hahn met in Copenhagen to discuss experiments that Hahn had conducted in his lab in Berlin. One key experiment showed that when uranium was bombarded with neutrons, it split into two, and one of the resulting elements, thought to be radium, behaved like barium.

Meitner and her nephew Otto Frisch, who was also a physicist, discussed the data and Meitner theorised that the uranium broke into barium (and krypton). If the element was barium, then this would be evidence of fission, but if it were radium, it could not be fission because radium was too big. But there was no theory for how uranium could decay into barium. The two of them worked out how this decay could occur, developing the theory of nuclear fission.

Meitner and Frisch came up with an experiment which would test this theory and asked Hahn to examine the byproducts of uranium bombardment in more detail. Hahn confirmed that it was indeed barium, not radium, proving Meitner’s theory of nuclear fission. It was clear that fission could produce large amounts of energy, and whilst this resulted in the Manhattan Project in the US, Meitner refused to have anything to do with research that might lead to the development of a bomb.

In 1944, Hahn received the Nobel Prize for Chemistry for his fission research, but Meitner’s work was ignored. She did, however, receive the Enrico Fermi Award in 1966 along with Hahn and his colleague Fritz Strassmann.

In 1992, element 109, which is currently the heaviest element in the known universe, was named Meitnerium (Mt) in her honour, one of just two elements named after women (the other, curium, was named after Marie Curie).

Further Reading

ALD22: Dr Kateryna Yushchenko, Computer Scientist

Kateryna Yushchenko

Dr Kateryna Yushchenko

Kateryna Yushchenko, Катерина Ющенко, was a Ukrainian computer scientist who developed the Address programming language, one of the world’s first high-level languages.

Yushchenko was born in 1919, in Chyhyryn in central Ukraine. In 1937, her father was arrested as a Ukrainian nationalist (he later died in a gulag) and when her mother tried to prove his innocence she was arrested and imprisoned for ten years. Yushchenko had just started studying at Kyiv University, but was expelled as a “daughter of enemies of the people”. The only institution that would accept her on a full state scholarship was Samarkand University in Uzbekistan.

Moving back to Ukraine after WW2, she was awarded her PhD in 1950 by the Kyiv Institute of Mathematics of the Ukrainian Academy of Sciences, the first woman in the USSR to get a PhD in physical and mathematical sciences in programming. She was a senior researcher for seven years, at which point she was appointed director of the Institute of Computer Science.

Two years later, the Institute bought the first MESM, or Small Electronic Calculating Machine, which was the first universally programmable computer in continental Europe, and Yushchenko was appointed head of the MESM laboratory. She realised that complex tasks could not be completed by the MESM, which had little memory and was very slow, without a high-level programming language, but that required a way for humans to program in that language.

To solve this problem, Yushchenko developed the Address programming language, which referred to memory cell addresses rather than numbers, several years before Fortran, COBOL or ALGOL. The Address programming language was used in most Soviet computers, including those that controlled the Apollo-Soyuz international space mission in 1975.

Yushchenko also worked on probability theory, algorithmic languages and programming languages, as well as developing automated data processing systems. She wrote a series of programming textbooks in the 1970s, including Elements of Programming, which was used across the USSR and the Eastern Bloc countries.

Further Reading