Dorothy Hodgkin was a British chemist who won the Nobel Prize in Chemistry in 1964 for her work on crystallography, particularly for being the first to use X-ray crystallography to determine the structures of important biochemical substances. She is best known for her pioneering research on penicillin and vitamin B12, which contributed significantly to the understanding of molecular structures and had a lasting impact on the fields of chemistry and biochemistry.

David W. Green is a biochemist known for his contributions to the field of biochemistry and molecular biology. While specific details about his work, research focus, and contributions may vary, he is typically recognized for his expertise in areas such as enzymology, protein structure, and function, or metabolic pathways. For precise and detailed information about his research, publications, and specific contributions to the field, it would be best to refer to scientific databases or publications.

Constance Tipper was a notable British scientist and engineer, recognized primarily for her contributions to materials science, particularly in the field of metallurgical engineering and fracture mechanics. She played a significant role in researching the properties of metals and how they behave under stress, which has applications in various engineering fields. Tipper's work is particularly well-regarded for its impact on understanding the mechanisms of failure in materials, which is crucial for the safety and reliability of structures and components in engineering.

Cecily Littleton is not a widely recognized figure in popular culture or history based on the information available up to October 2023.

Arthur Wilson is a notable figure in the field of crystallography, recognized for his contributions to the science of determining the atomic and molecular structure of crystals. He is best known for developing techniques in X-ray crystallography, which is a vital method used to analyze the arrangement of atoms within a crystalline solid.

Alfred Edwin Howard Tutton (1865–1945) was a British chemist noted for his contributions to the field of chemistry, particularly in relation to the study of dyes, pigments, and other colorants. He made significant advancements in understanding the structure and properties of various chemical compounds. Tutton also had a distinguished career in academia and was associated with several institutions where he contributed to both teaching and research.

Alexander Crum Brown (1838–1922) was a Scottish chemist known for his contributions to the field of chemistry, particularly in the study of chemical structures and molecular visualization. He is perhaps best known for developing a system of chemical notation that allowed for the representation of the three-dimensional structure of molecules in a two-dimensional format. His work laid the groundwork for later developments in the field of structural chemistry, making it easier to communicate complex chemical ideas.

Alan Lindsay Mackay is a prominent Australian mathematician known for his work in the field of mathematics, particularly in relation to partial differential equations and mathematical analysis. He has contributed significantly to various areas within mathematics and has published numerous papers throughout his career.

The British Crystallographic Association (BCA) is a professional organization dedicated to advancing the study and application of crystallography in the UK. The association aims to promote the activities and interests of crystallographers through meetings, publications, and collaboration with other organizations. The Presidents of the BCA are distinguished individuals within the field of crystallography who have served as the leaders of the association. They typically serve for a term, during which they help guide the organization's initiatives, events, and community engagement.

Tony Juniper is a British environmentalist, author, and campaigner known for his work in sustainability and conservation. He has held various positions in environmental organizations, including serving as the executive director of Friends of the Earth and as an advisor to government and non-governmental organizations on environmental issues. Juniper is also recognized for his writing, having authored several books that focus on topics like biodiversity, environmental policy, and the importance of the natural world.

Tom Burke is an environmentalist and a prominent figure in discussions surrounding environmental policy and sustainability. He is known for his work in promoting sustainable development and addressing climate change issues. Burke has served in various roles, including as a professor and an advisor to governmental and non-governmental organizations. He is also a co-founder of E3G (Third Generation Environmentalism), a think tank that focuses on advancing sustainable development and creating strategies for a low-carbon economy.

Paul Flynn was a British politician who served as a Member of Parliament (MP) for the Labour Party. He was born on 6th February 1935 and passed away on 17th January 2023. Flynn was elected to the House of Commons in 1987, representing the Newport West constituency in Wales. He was known for his strong advocacy on issues such as civil liberties, social justice, and anti-war policies.

Molly Scott Cato is a British politician and academic, associated with the Green Party of England and Wales. She has served as a Member of the European Parliament (MEP) for the South West England region from 2014 until the UK left the European Union in 2020. In her role as an MEP, Scott Cato focused on issues such as environmental sustainability, economic justice, and social equality.

Julie Christie is a British actress, widely regarded for her work in film and television. Born on April 14, 1940, in Chorlton-cum-Hardy, Manchester, England, she rose to prominence in the 1960s and became one of the leading actresses of her time.

Jonathon Porritt is a prominent British environmentalist, writer, and broadcaster, known for his work on sustainability and environmental issues. Born on July 26, 1950, he has played a significant role in promoting environmental awareness and sustainable development. He served as the Director of Friends of the Earth UK from 1984 to 1990 and was a founding member and later chair of the UK Sustainable Development Commission.

Hilda Murrell was a British woman known for being a prominent anti-nuclear activist in the 20th century. She was born in 1917 and became involved in environmental and peace movements, particularly in the context of rising nuclear weapons proliferation during the Cold War. Murrell was also known for her work in horticulture, but she gained significant public attention due to her activism. Her life took a tragic turn when she was murdered in 1984 at the age of 67.

As of my last knowledge update in October 2021, there isn't a widely recognized individual or entity specifically named "Gemma D'Arcy." It is possible that "Gemma D'Arcy" could refer to a person or character that gained prominence after my last update, or it could be a lesser-known figure in certain contexts. If you could provide more context or specify the field (such as entertainment, literature, etc.

David Lowry could refer to a few different individuals depending on the context. The most notable might be: 1. **David Lowry (Musician)**: An American musician, best known as the lead singer of the alternative rock band Cracker and as a founding member of the band Camper Van Beethoven. He has been influential in the music scene since the late 1980s. 2. **David Lowry (Film)**: A film director and writer known for his work in various genres.

Charles Secrett is a name that may refer to various contexts, but it is primarily associated with environmental activism and advocacy. He is known for his role as the former director of the UK-based environmental organization Friends of the Earth. Under his leadership, the organization was involved in various campaigns related to environmental issues, sustainability, and climate change.

William Duncan McNally is not a widely recognized public figure or concept in historical or contemporary contexts, based on the information available up until October 2021. It's possible that he may be a private individual, a local figure, or someone who has emerged in news or culture after that time.