Showing posts with label scientistoftheweek. Show all posts
Showing posts with label scientistoftheweek. Show all posts
Showing posts with label scientistoftheweek. Show all posts
Showing posts with label scientistoftheweek. Show all posts

Sunday, April 19, 2015

Scientist of the Week 5: Elsie Widdowson


This weeks #SOTW is Elsie Widdowson CBE CH FRS. The well-known British chemist and dietitian. Famous for her research on food composition tables and setting the limits of dietary intake of food, vitamins & minerals in World War 1.


Biography 

Elsie was born in Surrey, United Kingdom. Her schooldays were spent in south east London where her favourite subject was Zoology. But she had a dedicated chemistry teacher how encouraged her to study chemistry at university instead. Elsie studied chemistry at Imperial College London and graduated in 1928. She was one of the first females to graduate with a Bachelors of Science from Imperial College (there were only 3 women in her year of a group of 100 students). Elsie took her final exam after only 2 years of studying however had to continue at university for another year before her degree was awarded. In her final year, she spent time in the biochemistry lab presided over by Prof. Sammy Schyver. Elsie received an offer for a PhD interview from the department of plant physiology who found out that she was looking for a job.  Elsie received a PhD in chemistry in 1931 for her thesis on the carbohydrate content of apples.  However she did not want to continue her research in plants she was more fascinated by animals and humans.

Key Research

After gaining her PhD Elsie was notified about dietetics which she took a post graduate diploma in and was the basis for her interest in nutrition.  During her work at the University of London she met Dr McCance, she was very intrigued by his research on the chemical effects of cooking and she west and spoke to him. Elsie notified him of several errors on the fructose content of fruit in the standard nutritional tables. From then on they became scientific partners and worked together for the 60 years.  

Salt content

Prof McCance with Elsie’s help wanted to study salt deficiency in humans. They persuaded healthy young men and women to eat a salt-free diet and to lie and sweat in a hot air bath for two hours a day for 14 days. The subjects lay on a red plastic sheet inside the warmed-up apparatus for two hours every afternoon, keeping their temperatures between 100 and 101 °F. The amount of salt that they lost was measured by washing both them and the sheet down with a jet of distilled water after each session, and then analyse the washings; their water loss was measured by their loss of weight. Then, when they were salt deficient, they had to submit to a variety of tests, in particular of their renal function.

This research helped us understand that maintaining fluid and chemical balance is a standard part of treatment of patients with diabetic coma, kidney disorder and heart attacks, and of those who experience episodes of severe vomiting and fever, as well as the treatment of patients after surgery.

Iron content and digestion

One female patient at Kings College Hospital in particular had polycythaemia rubra vera. This lady was iron deficient.  She was treated with acetyl phenyl hydrazine and by so doing broke down enough red blood cells to liberate 5 grams of iron in her body and Elsie and McCance were surprised to see that none of it was excreted. So the research pair injected iron into each other and found that iron was not excreted from the body at all. Therefore iron has to be regulated through the intestinal absorption only. Today we know that iron overdose can occur if too much iron is ingested.    

The strontium accident

To detect how strontium was digested and excreted from the body Elsie and McCance injected themselves with strontium, every day for 6 days, increasing the dose when they realised nothing happened by the 5th day they had used up the entire original batch and had to sterilize some more strontium lactate from the original solution. On the 6th day both started to feel ill. McCance and Widdowson had suffered a pyrogen reaction, which occurred much more commonly then than now because purification techniques were then cruder. They recovered quickly but they never gave themselves any more strontium injections. Although they fell ill and the experiment was detrimental to their health; Elsie and McCance continued their research and they found that strontium was excreted through the kidney not the bowel.

Finally…

After the war, Elsie and McCance went to Germany in 1946 to continue their work and research the effect of the hostilities on the health and nutrition in communities affected by the conflict. They ended up staying 3 years in Germany; the research programmes that they commenced during this period lasted for 40 years this also resulted in the pair being elected as Fellows of the Royal Society. 

Solo Work

Elsie conducted a lot of research studies both in the UK and abroad. This included studies of the composition of the body, the differences between species and the changes in composition during development. Where she experienced working with samples ranging from humans and guinea pigs to a grey seal.

Awards

Elsie Widdowson CBE CH FRS. In 1976 she was made a Fellow of the Royal Society and the pinnacle of Elsie’s career was in 1993, when she became a Companion of Honour.


Referenceshttp://rsbm.royalsocietypublishing.org/content/48/483.full.pdf+htmlhttp://www.mrc-hnr.cam.ac.uk/about-us/history/dr-elsie-widdowson-ch-cbe-frs/http://en.wikipedia.org/wiki/Elsie_Widdowson

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Friday, March 27, 2015

Scientist of the Week 4: Francis Crick

Biography:

Francis Crick born on the 8th June 1916 in Northampton, United Kingdom, graduated from UCL in 1937. During World War 2 he worked as a scientist for the Admiralty Research Laboratory, working on the design of magnetic and acoustic mines.

In 1940 Crick married Ruth Doreen Dodd. Their son, Michael F.C Crick is a scientist. They were divorced in 1947. In 1949 Crick married Odile Speed. They have two daughters, Gabrielle A. Crick and Jacqueline M.T. Crick.  The family lived in a house called the “The Golden Helix” appropriately named by Crick, and it made a good conversation topic with his friends.

In 1947 Crick made the transition from physics into biology, which he described as "almost as if one had to be born again." His early studies at Cambridge were supported by a studentship from the Medical Research Council (MRC).

In 1949 he joined the MRC Unit headed by Max Perutz, which subsequently became the MRC Laboratory of Molecular Biology. During this period he worked on the X-ray crystallography of proteins, obtaining his PhD in 1954.

In the beginning of 1951 a new friendship started between Crick & James Watson (who was 23 at the time). They were both fascinated by the essential query of how genetic information could be stored in molecular form, leading in 1953 to the proposal of the double-helical structure for DNA. Crick then concentrated on the biological implications of the structure of the DNA molecule, developing further insights into the genetic code − including the so called “central dogma” describing the flow of information from DNA to RNA to protein. Crick was made a Fellow of the Royal Society in 1959.

Crick worked at the University of Cambridge for 30 years up until 1977. For the rest of his career, Crick continued to work in the Salk Institute for biological studies, in La Jolla, California, USA, and also a professor at the University of California, San Diego.

Francis Crick was celebrated for his intelligence, openness to new ideas, and his collaborations with scientists working in different fields of expertise.

Key Research:

After gaining his studentship in the MRC, in 1949, He became a research student for the second time in 1950, as a member of Caius College, Cambridge, and obtained a PhD in 1954 on a thesis entitled ‘X-ray diffraction: polypeptides and proteins’.

During this period, Crick was studying and devised a theory of X-ray diffraction by a helix at the same time Linus Pauling and Robert Corey suggested the alpha- keratin pattern was due to alpha-helices coiled around each other.

Watson & Cricks friendship blossomed in 1951, and in the year 1953 the duo proposed the structure of the double-helical structure of DNA and a theory for its replication. Subsequently they suggested a general theory for the structure of small viruses.

Crick, in collaboration with Alex Rich, has proposed structures for polyglycine II and collagen and (with Alex Rich, D R Davies, and James Watson) a structure for polyadenylic acid.

Later, in collaboration with Sydney Brenner, Crick focused more on biochemistry and genetics leading to ideas about protein synthesis (the ‘adaptor hypothesis’), and the genetic code.

Nobel Peace Prizes:

Francis Crick was awarded one-third of The Nobel Prize in Physiology or Medicine in 1962 along with James Watson and Maurice Wilkins. All three were co-awarded the prize for their research on the identification of the structure of DNA and nucleic acids.

“Prize motivation:"for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material"


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References:
http://www.nobelprize.org/nobel_prizes/medicine/laureates/1962/crick-bio.html

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Friday, March 20, 2015

Scientist of the Week 3: Maud Leonora Menten



For this week’s Scientist of the Week segment, I have chosen: Maud Leonora Menten of the Michaelis-Menten equation famous for her core work in biochemistry, taught in college, used daily in biochemistry research and applications. She was amazing and relentlessly pursued her work despite many obstacles.

Biography:

Maud Menten was born March 20, 1879 in Port Lambton, Ontario, Canada and studied medicine at the University of Toronto (B.A. 1904, M.B. Physiology 1907, M.D. 1911). She was among the first women in Canada to earn a medical doctorate. She completed her thesis work at University of Chicago.



Miss Menten was woman who wore “Paris hats, blue dresses with stained-glass hues, and Buster Brown shoes.” She drove a Model T Ford through the University of Pittsburgh area for some 32 years and enjoyed many adventurous and artistic hobbies.

She was an extremely motivated and a hard-worker; she continued to work all her life until she was too sick to no longer work.  Menten was so dedicated to her work so she learnt to communicate in German and was able to communicate in a total of 6 languages throughout her life including Russian, French, German, Italian, and at least one Native-American language.

Key Research / Awards:

Miss Menten headed for Germany by ship, in the same year that the Titanic had sank, despite being advised not to. She was determined to work with Leonor Michaelis- the well-known, German, biochemist.  They worked together to solve the mystery of enzyme kinetics, studying the rates and mechanisms of enzymatic reactions. Together they devised the Michaelis-Menten Equation, the famous equation that is vital till today which calculates the rate of an enzyme reaction and is taught to all biochemistry undergraduates today.



After travelling from Germany to the USA, Miss Menten continued her PhD in 1916 worked at the University of Pittsburgh (She was awarded a professorship in 1950). She then went to become a pathologist at the Pittsburgh Children’s Hospital in 1926 where she studied histochemistry and paediatric pathology.

She’s credited for having conducted the first separation of proteins by electrophoresis, and she developed a staining method using azo dyes that’s still used in histochemistry today. In 1950 Menten retired and returned to Canada where she continued to work here she continued to do cancer research at the British Columbia Medical Research Institute till 1955.

Over her entire career she wrote and co-wrote about 100 research papers, many of which are historic contributions.

Nobel Peace Prize:

She may not have won one but she definitely deserved one!

“I’ve stirred them up, so now I can go.” - Maud Leonora Menten

References



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Friday, March 13, 2015

Scientist of the Week 2: Ahmed Zewail

This weeks Scientist of the Week #SOTW is Ahmed Zewail, the famous, Egyptian scientist & Nobel laureate, for his amazing research in femtochemistry: studying chemical reactions across femtoseconds (1 fs= 10-15 seconds). 

Biography:

Born on February 26, 1946 in a city not so far from Alexandria, Egypt; Zewail “lived an enjoyable childhood”.  His family’s dream was to see Zewail achieve a high degree abroad and return to Egypt to become a university professor.  Zewail completed his degree in Alexandria University with First Class Honours and it is the same place where he realised his strong passion for science especially the physical sciences.  

Zewail then went onto complete his Masters and PhD in Alexandria University where he was employed as a demonstrator (“Moeid”) where he gave lectures to undergraduates.  He then travelled o the United States where he completed his PhD in the University of Pennsylvania with advisor Robin M. Hochstrasser. Zewail then moved to Berkeley, U.S.A to complete a post-doctoral fellowship at the University of California, Berkeley with advisor Charles B. Harris.

After completing his post-doc, Zewail was awarded a faculty appointment at the California Institute of Technology where he has been working ever since 1976. In 1990 he was made the first Linus Pauling Chair in Chemical Physics.

Key research / awards

Of the notable works that Zewail has worked through; is his work in femtochemistry, studying chemical reactions across femtoseconds (1 fs= 10-15 seconds).  Before the late 1980’s it was almost impossible to study the events that occur in a chemical reaction, however Zewail was able to view the motion of atoms and molecules based on new laser technology capable of producing light flashes just tens of femtoseconds in duration (a.k.a femtosecond spectroscopy).  

For his contributions to science and for his public service, Dr. Zewail has garnered honours from around the globe. Fifty Honorary Degrees in the sciences, arts, philosophy, law, medicine, and humane letters have been conferred on him, including those from Oxford University, Cambridge University, Peking University, École Normale Supérieure, Yale University, University of Pennsylvania, and Alexandria University.

Recent research

4D Microscopy:  Professor Zewail’s current research is focused on the structural dynamics in chemistry and biology with focus on the physics of elementary processes in complex systems. The main research is based in producing four-dimensional (4D) ultrafast electron microscopy and diffraction for atomic –scale visualization in space and time.  Together with spectroscopy and large-scale computations, the goal is to understand complexity and nature of physical, chemical and biological transformations.
Prof. Zewail also is devoted to giving public lectures to enhance awareness of the value of knowledge gained from fundamental research, and helping the population of developing countries through the promotion of science and technology for the betterment of society.

Nobel Peace Prize

At 5:40 in the morning on Tuesday, October 12, Ahmed Zewail got a phone call - it was the Royal Swedish Academy of Sciences informing him he had won the 1999 Nobel Prize in chemistry. The citation reads, in part, that Zewail "is being rewarded for his pioneering investigation of fundamental chemical reactions, using ultra-short laser flashes on the time scale on which the reactions actually occur"...  Dr Zewail studied atoms and molecules in “slow motion” during a reaction and seen what actually happens when chemical bonds beak and new ones are created.

Described as the world’s fastest camera, this utilises laser flashes of such short duration that are at the time scale on which the reactions actually happen – femtoseconds (fs). One femtosecond is 10-15 seconds that is 0.000000000000001 seconds. This area of chemistry as named femtochemistry.

Femtochemistry helps us understand why certain chemical reactions take place but not others, and also determine the speed and yields of different reactions.  This will aid the future research into the mechanisms of life and how the medicines of the future should be produced.

“At the age of 21, as a Moeid, I believed that behind every universal phenomenon there must be beauty and simplicity in its description. This belief remains true today.”
-          Ahmed H. Zewail, Autobiography

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Friday, March 06, 2015

Scientist of the Week - Week One

Choosing a scientist to begin the first week of Scientist of the Week was difficult but after a lot of thinking and contemplating, I have chosen…………… Marie Curie! The first woman to win a Nobel peace prize.

Biography
Key Research
X-ray work during WW1
Nobel Peace Prizes
___________________________________________________________

Marie Curie, born in Warsaw on 7 November 1867, is a Polish-born physicist and chemist. Curie was the youngest of five children. She studied at Warsaw’s clandestine Floating University and began her scientific training in Warsaw.

Later in 1891, Curie’s sister offered her temporary accommodation in Paris and she immediately took up the offer and moved to Paris, France where she started her studies in Sorbonne University where she read physics and mathematics and earned higher degrees and conducted her subsequent scientific work.

In 1894 Marie met Pierre Curie in Paris (a scientist working in the city) and they married a year later. Pierre and Marie had two daughters; Irene (born 1898) and Eve (born 1904).
On 4 July 4 1934, at the Sancellemoz Sanatorium in Passy, France at the age of 66, Marie Curie died of pernicious anaemia, a condition she developed after years of exposure to radiation through her work.


The Discovery of Polonium and Radium

Six months after their marriage Marie Curie found the topic of her thesis: Uranium rays - carrying on research from a new discovery by Professor Henri Becquerel.
Marie Curie was the first person to give radioactivity its name. Before more radioactive elements had been discovered, only uranium was known.  The first lady of science obtained a mineral called pitchblende which is called so because it is black. Curie knew that it was radioactive and contained uranium but she wanted to understand what other element(s) was responsible for its radioactivity.  

Pierre joined Marie in her work with pitchblende where they ground and separated the different elements present and eventually they extracted a black powder, three hundred and thirty times more radioactive than uranium, which they called Polonium (atomic number 84). Marie named the newly discovered element, Polonium after her home country, Poland.
In 1898 the Curies published strong evidence for the discovery of Radium, even though they didn't have any sample for it. Marie Curie then bought several tonnes of uranium-extracted pitchblende and started to extract tiny quantities of radium. In 1902 Marie finally isolated radium after a long and grueling journey.


In World War 1, Marie Curie worked to develop small, mobile X-ray units that could be used to diagnose injuries near the battlefront. She worked with her daughter Irene, then aged 17, at casualty clearing stations close to the front line, X-raying wounded men to locate fractures, bullets and shrapnel.

Marie Curie was awarded a Nobel Peace Prize in 1903 in physics with husband Pierre Curie and jointly with Prof. Henri Becquerel (for their work on radiation phenomena) and again 1911 in chemistry (for discovering the element Polonium and Radium), making her the first woman in science history to ever win the Nobel Peace Prize.

Marie Curie definitely deserves to be the first Scientist of the Week for not only her hard work in radiation (and sacrificing her health for research) but also for becoming an outspoken advocate for women in the sciences.

“It is my earnest desire that some of you should carry on this scientific work and keep for your ambition the determination to make a permanent contribution to science.”

-          Marie Curie

References

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Friday, February 27, 2015

New Segment: Scientist of the Week!


After my previous blog post Science: It's a Girl Thing I have decided to start a new segment where I will be featuring one scientist from different branches of science and could be male or female and provide a profile / case study dedicated to that scientist every week. This segment will be: Scientist of the Week and will be posted every Friday commencing from Friday 6th March 2015 !

Can you guess which scientist I will be starting with?

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