Johannes Wislicenus

Johannes Winlicenus was born on June 24, 1835 in Kleineichsted, Saxony, the son of Gustav and Emilie Winlicenus. He was born into a devout protestant family that in the 17th century had been forced to flee their native Poland to Saxony on account of their religion. His father was a protestant minister who in 1853 published a book in which he attempted to liberate people from what he thought was a "superstitious adoration" of the Bible. The book was considered blasphemous by the authorities, and so it was destroyed and he was sentenced to two years in prison. Instead he fled with his family to Boston, Massachusetts. Johannes who was 18 at the time served as an assistant to chemist Eben Horsford at Harvard University and in 1855 he as appointed lecturer at New York's Mechanic's Institute. Returning to Europe in 1856 he went to the University of Halle where he resumed his studies and served as an assistant to Wilhelm Heintz. He had finished the requirements for his PhD by 1859 but as a condition of his graduation he was asked to renounce the teachings of his father and cease his political activities. He refused and then went to the University of Zurich where he finished his doctorate in 1860. He served as a lecturer at the University of Zurich until 1868 when he became a professor of chemistry there. In 1860 he became professor of chemistry at the Swiss Pyrotechnical Institute and he served both professorships simultaneously. In 1872 he became the chair of chemistry at the University of Wurzburg and in 1885 he became a professor of chemistry at the University of Leipzig.

Winlicenus' research was in organic chemistry. Starting in 1868 he began studying lactic acid. Lactic acid is a  carboxylic acid that is a metabolite of glucose. In his studies he found that there were two types of lactic acid which had different chemical properties. While these two chemicals have the same chemical formula (the same numbers and types of atoms) they have different structures. In the case of lactic acid (a three carbon long carboxylic acid) one form has a hydroxyl group attached to the carbon adjacent to the carbonyl carbon and the other form has a hydroxyl group attached to the terminal carbon, the carbon on the opposite end of the three carbon chain from the carbonyl. Because these two molecules have different structures they have different properties, but the formulas for both compounds are both C3H6O3. Winlicenus called these chemicals with the same formula but different structures structural isomers.

Another important experiment carried out by Winlicenus, working in collaboration with his friend Aldolf Fick a professor of physiology at the University of Zurich, showed that carbohydrates and fats were the principal source of muscular energy. The pair ascended the Faulhorn, taking with them only food from which proteins had been excluded. While they climbed the pair monitored their nitrogen metabolism and found that the the break down of proteins accounted for less than one third of the energy generated by their metabolism.

Wislicenus was elected a foreign member of the British Royal Chemical Society in 1888 and member of the Royal Society of London in 1897 which presented him with its Davy Medal in the following year.

Winlicenus died on December 5, 1902.


References:

P.F.F.; "Johannes Wislicenus. 1835-1902"; Proceedings of the Royal Society (1907) 78:iii-xii

Ramberg, Peter J.; Chemical Structure, Spatial Arrangement: An Early History of Stereochemistry. 1874-1914; Ashgate Publishing Ltd.; 2003

"Johannes Wislicenus, Biography", retrieved from: my.rsc.org

Johannes Wislicenus Wikipedia Entry

Giovanni Cassini

Giovanni Domenico Cassini was born in Perinaldo in northern Italy on June 8, 1625. He was brought up by his maternal uncle who looked after his education. He attended school in Valebone for two years and then attended the Jesuit college in Genoa where he studied astrology and astronomy. Although he studied astrology he admitted that it was not prophetic but at the time there was little separation between astronomy and astrology. In 1644 he was invited to become an assistant at the Bologna Observatory and six years later, when he was still only 25, he was made professor of astronomy and mathematics at the University of Bologna. In addition to his astronomical work, Cassini also did river engineering work and engineered fortifications for the Holy See. In 1668 he was invited to help set up the new Paris Observatory by Louis XIV of France. Pope Clement IX agreed to the trip believing it would be short, only two years at the most. Cassini once established in the new observatory made no effort to return to Italy. He remained at the Paris Observatory and three generations of his descendants ran it until 1794.

Cassini is probably best remembered for discovering the Cassini Division, a open space between Saturn's A and B rings. Before Cassini it was believed that the rings of Saturn were one large solid ring structure orbiting the planet. Cassini's observations of the rings showed that there were breaks between the rings. We know now that the rings of Saturn are not solid at all, but made up of orbiting pieces of ice and debris. Cassini was also responsible for identifying four of the moons orbiting Saturn: Iapetus, Rhea, Tethys, and Dione. Cassini also shares credit for discovering the red spot on Jupiter with English scientist Robert Hooke Although Cassini initially believed in a geocentric model for the solar system he eventually came to believe in a solarcentric model, similar to that proposed by Nicolas Copernicus.

In addition to craters on the moon and Mars named after him Cassini also has an asteroid named after him. Additionally NASA's unmanned probe that is currently exploring Saturn and its moons is named after him (for more information on the Cassini probe see here).

As he grew older Cassini's vision failed him and his son Jacques began to run the Paris Observatory. Cassini died on December 14, 1712.


References:

Connor, Elizabeth; "The Cassini Family and the Paris Observatory"; Astronomical Society of the Pacific Leaflets (1947)218:146-153

O'Connor, J.J. and Robertson, E.F.; "Giovanni Domenico Cassini"; Retrieved from: history.mcs.st-anderews.ac.uk

Giovanni Domenicao Cassini Wikipedia Entry

Otto Loewi

Otto Loewi was born in Frankfurt, Germany on June 3, 1873. His father Jacob was a Jewish wine merchant. He attended gymnasium school in Frankfrurt and then the Universities of Munich and Strasbourg as a medical student. Not really interested in clinical medicine, Loewi applied himself to physiology and pharmacology. He completed his thesis on the effects of arsenic, phosphorus, and other substances on an isolated frog heart. After completing his medical education in 1896, Loewi spent a year as an assistant doctor in a hospital in Frankfurt. There he was frustrated by the lack of effective treatment for tuberculosis and pneumonia patients. This convinced him that he did not want to practice clinical medicine and opted instead for a research career. He was able to get a position as an assistant to Hans Meyer starting work in Meyer's laboratory in Marburg in 1898. Working in Meyer's lab he researched metabolism. While working there he proved that animals were able to synthesize proteins from protein degradation products (amino acids). Before that it was believed that animals could only make proteins from other intact proteins.

In 1903 he was appointed professor of pharmacology at the University of Graz in Austria. While working at Graz he conducted an experiment that proved that the transmission of nerve impulses to the heart was conducted by a soluble factor, the idea for which came to him in a dream. First he isolated two frog hearts, one with the vagus nerve still attached. The vagus nerve is part of the parasympathetic nervous system and causes the heart muscle to slow its beating. First he stimulated the attached vagus nerve, which caused the attached heart to slow its beating. Taking a sample of the fluid surrounding the heart with the attached nerve he applied it to the second heart. The second heart slowed its beating in response to the added fluid. Loewi named the unknown soluble factor that caused the second heart to slow its beating "vagustoff". It was later identified as acetylcholine. The transmission of nerve impulses between different neurons and at the nerve interfaces with muscles are conducted by soluble chemicals called neurotransmitters. For his pioneering work establishing the importance of neurotransmitters Loewi shared the 1936 Nobel Prize in medicine and physiology with Henry Dale. He would remain in Austria until 1938 when he was forced to leave due to the German occupation. After a brief stays in Belgium and the United Kingdom, Loewi emigrated to the United States in 1940

Other honors won by Loewi include honorary doctorates from the University of Graz, Yale University, University of New York (where he worked after he emigrated to the United States) and the University of Frankfurt. He was made an honorary member of the Physiological Society of London and a member of the Royal Society.

Loewi died on December 25, 1961.


References:

Valenstein, Elliot S.; The War of Soups and the Sparks: The Discovery of Neurotransmitters and the Dispute Over How Nerves Communicate; Columbia University Press; 2005

Otto Loewi Nobel Biography

Ottto Loewi Wikipedia Entry

Bart Bok

Bartholomeus Jan Bok was born on April 18, 1906 in Hoorn, Netherlands. His father was a sergeant major in the Dutch army and he was born on a military base, that later became a monument. After World War I, Bok's family moved to The Hague, were he went to high school. Also while living there Bok joined the Boy Scouts and he attributed his early interest in astronomy to an astronomy test given to him by a scoutmaster. Bok failed the test and afterward made an effort to study astronomy. After graduating high school he won a scholarship to study at Leiden University where he earned his bachelors, and then when to the University of Gronigen, where he earned his doctorate in astronomy. Bok then took a job working for Harlow Shapely at the Harvard Observatory. Bok worked at Harvard Observatory from 1929 to 1957. In 1957 Bok moved to Australia where he served as director of the Mount Stromlo Observatory until 1966, when he moved to the University of Arizona and the directorship of the Steward Observatory.

Bok's research at Harvard involved mapping stars of the Milky Way galaxy. He also was involved with radio astronomy, and turned Harvard into a center for radio astronomy with the installation of Agassiz Station, which he engineered. Bok worked with his wife, Priscilla, who was also an astronomer. The pair wrote a popular book about the Milky Way that went through six printings. Bok is probably best remembered for his study of dark globular clouds. These globular clouds composed of hydrogen and dust range in mass between 2 and 50 solar masses and are light years across. Bok theorized that these clouds could be the site of stellar formation. Star formation occurs when gravity collapses a cloud of hydrogen gas so compactly that a fusion reaction begins, converting hydrogen into helium and releasing energy. Bok's prediction has been proven to be correct and consequently these dark globular clouds are called Bok globules.

Awards won by Bok during his career include the Bruce Medal, from Astronomical Society of the Pacific. Bok served as president of the American Astronomical Society from 1972-74. He and his wife also have a lunar crater and an asteroid named after them.

Bok died on August 5, 1983 of a heart attack.


References:

Graham, J.A., Wade, C.M, and Price, R.M.; "Bart J. Bok: 1906-1983"; in Biographical Memiors; National Academy Press; 1994

Lada, C.J.; "Obituaries: Bart Bok"; Quarterly Journal of the Royal Astronomical Society (1987)28:539

Interview of Bart J. Bok by David Devorkin on May 15, 1878; Retrieved from aip.org

Sir Harold Jefferys

Harold Jeffrys was born April 21, 1891 in the village of Fatfield, near the city Sunderland, England, where his father was a schoolmaster and his mother a school teacher at the village school. He attended school in Fatfield and he was awarded a scholarship to study at Rutherford University in Newcastle-upon-Tyne. In 1907 he went to Armstrong College, also in Newcastle graduating in 1910 with distinction in mathematics. He then went to St. John's College, Cambridge earning on of four mathematical scholarships. He became a fellow at St. John's in 1914 and remained there throughout his career.

Jefferys' studies encompass many related fields, including astronomy, pure mathematics, and geophysics. He was particularly interested in seismology and using the records of earthquakes to discern information about the structure of the Earth. By studying the rates at which seismic waves travel through the Earth's crust he was able to determine that it is composed of at least two layers and that the Earth has a molten core. We now know that the Earth's core has molten outer core and a solid inner core. Although his studies advanced our knowledge of the structure of the Earth he remained skeptical of the theory of plate tectonics, the currently accepted theory of movements of the Earth's crust. Much of Jeffrey's work was completed before the advent of artificial satellites and deep ocean drilling used to do geophysical research today.

Jeffery's work in astronomy focused on the planets Neptune and Uranus. In 1923 he proposed that these planets would have surface temperatures of the order of -120 Celsius. This was disputed at the time, but has been proven accurate. He also published a book on probability theory that was influential in that field. Honors won by Jeffry's include election to the Royal Society in 1925, a Gold Medal from the Royal Astronomical Society in 1937 and the Copely Medal from the Royal Society in 1961. He was knighted in 1953.

Jeffrys died on March 18, 1989.


References:

O'Connor, J.J. and Robertson, E. F.; "Harold Jeffrys"; retrieved from history-mcs.st-and.ac.uk.

Mumford, George S.; "Jeffrys, Harold"; in Biographical Encyclopedia of Astronomers; Springer; 2007

Harold Jeffrys Wikipedia Entry

Alan MacDiarmid

Alan Graham MacDiarmid was born in Masterton, New Zealand on April 14, 1927. His was one of five children. His family was poor and his father, an engineer was unemployed during the great depression of the 1930s. The family moved to Lower Hutt, closer to Wellington where work was believed to be more plentiful. MacDiamid became interested in chemistry as a child from reading his father's chemistry text and books he checked out from a local library. During a Guy Fawkes Day celebration he produced his own fireworks. After attending Hutt Valley High School, he entered Victoria University in Wellington in 1943. He took work there as a lab boy and finished his BSc in 1947. He remained at Victoria University as a graduate student, finishing his MSc. He attended the University of Wisconsin Madison on a Fullbright Fellowship, earning a MS in 1952 and a PhD in 1953. He earned a second PhD from Sidney Sussex College, Cambridge in 1955. After finishing his second doctorate he was a member of the junior faculty for a year at the University of St. Andrews and then became a professor at the University of Pennsylvania, were he remained for the majority of his career. In 2002 he joined the faculty at the University of Texas, Dallas.

MacDiarmid's research focused on the chemistry of silicon and non-metallic conductors. Metals (elements in the metallic region of the periodic table) are good conductors of electricity. Non-metallic elements, such as carbon, do not conduct electricity. (see here for an blog post on metal and non-metal elements) Mac Diarmid's lab developed carbon polymers that were able to conduct electricity. They developed polyacetylene, a carbon polymer, that was able to conduct electricity.  They determined that the reason the normally non-conductive carbon polymer was able to conduct electricity  were due to impurities, such as the catalyst used to create the polymer. They learned to "dope" the polymers they created, creating polymers that had widely ranging electrical conductivities. Since their discovery conductive polymers have been developed and used to make electrical capacitors that could be used as environmentally friendly batteries. For his work discovering conductive polymers, MacDiamid shared the 2000 Nobel Prize in chemistry with Alan Heeger and Hideki Shirakawa.

Other honors won by MacDiamid include the Rutherford Medal from the Royal Society of New Zealand, the American Chemical Society's materials award, and the Order of New Zealand.

MacDiamid died on Febrary 7, 2007.


References:

Callaghan, Paul: "MacDiamid, Alan Graham: 1927-2007"; in the Dictionary of New Zealand Biography retrieved from www.teara.nz.gov

MacDiamid, Alan; Nobel Autobiography

Alan MacDiamid Wikipedia entry

Edwin G. Krebs

Edwin Gerhard Krebs was born on June 6, 1918 in Lansing, Iowa. He was the son of a Presbyterian minister, William Carl Krebs, and Louise Helen (Stegman) Krebs, who was a schoolteacher before she married. Krebs' family moved many times during his youth as his father took different ministry positions. Krebs' father died when he was sixteen and a freshman in high school. After his father's death the family moved to Urbana, Illinois, where Krebs attended the University of Illinois majoring in chemistry. He earned a scholarship to Washington University in St. Louis, Missouri, where he studied medicine. After completing a 18 month residency and serving as a medical officer in the U.S. Navy, Krebs was unable to find a clinical position. Instead he took a postdoctoral research position working in the laboratory of Carl and Gerty Cori at Washington University. In 1948 Krebs was appointed assistant professor of biochemistry at the University of Washington, where he remained until 1968. In 1968 he moved to the University of California Davis, where he served as the founding chairman of the department of biological chemistry. Krebs returned to the University of Washington in 1977.

Krebs' research involved enzymes, the protein molecules that catalyze biochemical reactions. While at the University of Washington, Krebs worked with Edmond Fisher and the pair discovered the reversible phosphorylation of glycogen phosphorylase which serves to activate the enzyme. Glycogen phosphorylase is the enzyme that removes monosacharides from glycogen (the polysacharide used to store glucose for future use) so that they can be broken down into energy. Glycogen phosphorylase exists in two forms A and B. The Cori's had found that form B is inactive unless it is in the presence of adenosine monophosphate (AMP) and that form A is active without AMP. They also knew from the experiments of the Cori's that the active A form degrades into the inactive B form. Krebs and Fischer discovered that the B form is reversibly phosphorylated (phosphate is added to the protein molecule) converting it into the A form, which causes it to be activated so that it can break down glycogen. This was the first discovery of reversible phosphorylation which is a ubiquitous mechanism that serves as a means of activating many enzymes and transducing biochemical signals. For their discovery of the regulation of glycogen phosphorylase by phosphorylzation Krebs and Fischer were awarded the 1992 Nobel Prize in medicine and physiology.

Krebs died on December 9, 2009.


References:

Fischer, Edmond H.; "Edwin G. Krebs (1918-2009)"; in Biographical Memoirs; 2010; National Academy Press

Krebs, Edwin G.; "Nobel Autobiography"

Edwin G. Krebs Wikipedia Entryhttp://en.wikipedia.org/wiki/Edwin_G._Krebs