Griffith's experiment, reported in 1928 by Frederick Griffith, was the first experiment suggesting that bacteria are capable of transferring genetic information through a process known as transformation. Griffith's findings were followed by research in the late 1930s and early 40s that isolated DNA as the material that communicated this genetic information. Pneumonia was a serious cause of death in the wake of the post-WWI Spanish influenza pandemic, Griffith was studying the possibility of creating a vaccine. Griffith used two strains of pneumococcus bacteria which infect mice – a type III-S, virulent, a type II-R strain, nonvirulent; the III-S strain synthesized a polysaccharide capsule that protected itself from the host's immune system, resulting in the death of the host, while the II-R strain did not have that protective capsule and was defeated by the host's immune system. A German bacteriologist, Fred Neufeld, had discovered the three pneumococcal types and discovered the quellung reaction to identify them in vitro.
Until Griffith's experiment, bacteriologists believed that the types were fixed and unchangeable, from one generation to another. In this experiment, bacteria from the III-S strain were killed by heat, their remains were added to II-R strain bacteria. While neither alone harmed the mice, the combination was able to kill its host. Griffith was able to isolate both live II-R and live III-S strains of pneumococcus from the blood of these dead mice. Griffith concluded that the type II-R had been "transformed" into the lethal III-S strain by a "transforming principle", somehow part of the dead III-S strain bacteria. Today, we know that the "transforming principle" Griffith observed was the DNA of the III-s strain bacteria. While the bacteria had been killed, the DNA had survived the heating process and was taken up by the II-R strain bacteria; the III-S strain DNA contains the genes. Equipped with this gene, the former II-R strain bacteria were now protected from the host's immune system and could kill the host.
The exact nature of the transforming principle was verified in the experiments done by Avery, McLeod and McCarty and by Hershey and Chase. Avery, MacLeod, McCarty. "Studies on the Chemical Nature of the Substance Inducing Transformation of Pneumococcal Types: Induction of Transformation by a Desoxyribonucleic Acid Fraction Isolated from Pneumococcus Type III". Journal of Experimental Medicine. 79: 137–158. Doi:10.1084/jem.79.2.137. PMC 2135445. PMID 19871359. CS1 maint: multiple names: authors list Daniel Hartl. Genetics: Analysis of Genes and Genomes, 6th edition. Jones & Bartlett. 854 pages. ISBN 0-7637-1511-5 Lehrer, Steven. Explorers of the Body. United States: iUniverse, Inc. ISBN 0-595-40731-5
David Kelly is a British radio presenter and DJ from Northampton, England. He is employed by Bauer Radio for Radio City 96.7 and Key 103. Kelly worked at Kix 96 FM until 2000 freelanced as a radio presenter, he joined the Newcastle upon Tyne, England based Galaxy North East where he presented the weekday evening show and a networked Saturday dance show. After two years, the then-owners of Galaxy decided to network his radio shows, resulting in him moving to the network centre, Galaxy Yorkshire in Leeds, England, he presented a Saturday dance show on the Global Radio owned Capital London alongside his Galaxy shows and in June 2009, he left Galaxy to work at Capital FM full-time, presenting the 2200–0200 slot. On 3 January 2011, the Hit Music networks merged to form the Capital network; as a result, his late night show could therefore be heard across the UK on the new network with a slight change of show time, as he was moved to Sunday to Thursday from 2300–0300. From 3 January, he was once again broadcasting on his old Galaxy stations, under the new Capital name.
On 11 April 2011, Radio City 96.7 announced that Kelly would become drivetime presenter from mid June 2011, he presented his final Capital broadcast on 29 April 2011. Kelly presented the weekday drivetime show from 1500–1900 on Radio City 96.7 from 13 June 2011 until late April 2014. Whilst on the drivetime show He presents a Saturday evening "in the mix" slot from 2200–0200 from Key 103 which he started on 18 June 2011; this show is broadcast across the Bauer Network to 16 stations across Scotland. From 11 February 2012 he presents "Saturday Night Live" on Radio City 96.7. He hosted the "House Party" on Sunday nights on Radio City 96.7 where he broadcasts live from his house. Dave has a dog called Clive who appears on his radio shows. Dave was the main cover for the Radio City 96.7 breakfast show hosted by Simon Ross a.k.a. Rossie & Co. up until 2 May 2014 when Dave began a 2-year contract placing him at the centre of the all new Radio City 96.7 Breakfast Show, co-hosting with former Juice FM breakfast presenter Leanne Campbell.
The shake up came as part of a revamp of the stations schedule to mark the 40th year of the Radio City 96.7 launch with former host Simon Ross taking over the 10am-2pm show. Alex James took over Dave's drivetime show in May 2014 before handing the permanent role over to Scott Hughes. Aside from his UK radio shows, Kelly presents the Drive Time show for Cayman Islands radio station X1071; as well as the Mon – Fri 3–7 shift on X107.1 he presents the Saturday Dance show from 8–12. Kelly mixes the music for the No.1 National Radio network in Australia Nova FM on their'Saturday Night Nova' show. Dave Kelly on Twitter
Waldo station is a bus station, former train station, in Waldo, Florida. It serves Amtrak's Thruway Motorcoach bus system and served trains for Amtrak and other rail operators; the station is located at State Road 24 in Waldo, Florida. The original Waldo train station was built by the Seaboard Air Line Railway as a two-story structure with a large freight room, was a divisional headquarters. In 1930, the top floor and part of the freight room were removed. In 1963, the old building was replaced by the current structure. Beyond the merger with the Atlantic Coast Line Railroad in 1967, the takeover of passenger service by Amtrak in 1971, Waldo station served the Silver Meteor and the Palmetto, rerouted to the CSX S-Line in 1979, until it was truncated to Savannah, Georgia on November 1, 2004, prompting Amtrak to revive Silver Star service to Tampa along the same line shared by the current Silver Meteor, part of the suspended Sunset Limited. Today Waldo only serves as a stop for Amtrak Thruway Motorcoach buses between Jacksonville, Ocala, Dade City and Tampa.
Media related to Waldo at Wikimedia Commons Waldo Amtrak Station City of Waldo History