Use of corpus analysis tools in medical corpus processing

1. Use of corpus analysis tools in medical corpus processing Evelina Miščin evelinamiscin@yahoo.co.uk

2. Introduction • Research questions • Methodology • TermeX • Simple Concordance • Collocation extract • Conclusion • Future research

3. Introduction • the use of corpus analysis tools • three tools • TermeX • Simple Concordance • Collocation Extract

4. Firth (1957) – definition of collocation • Other theoreticians (Halliday, Ridout & Waldo-Clarke, Backlund, Seaton, Crystal, Cruse, Zhang) • Collocations – importance • Word - text

5. Medical English • Previous studies – social sciences • Natural sciences – Thomas, Baker, Francis, Pearson

6. Analysis of collocations – corpus • The first corpus – 1961 – 135,000 words • Brown’s corpus • LOB

7. Sinclair (1991) • Lexical repetition • Function/structure words - content/lexical word

8. Upward collocations –e.g. donate blood • The most frequent nouns • Verb collocations

9. Research questions • The most frequent nouns • The use of corpus analysis tools • Log likelihood / Mutual information

10. Methodology • Merck’s Manual of Medical Information • Files – 1,065,181 words • 25 files

11. BRAIN, SPINAL CORD AND NERVE DISORDERS BIOLOGY OF THE NERVOUS SYSTEM The nervous system has two distinct parts: the central nervous system (the brain and spinal cord) and the peripheral nervous system (the nerves outside the brain and spinal cord). The basic unit of the nervous system is the nerve cell (neuron). Nerve cells consist of a large cell body and nerve fibers—one elongated extension (axon) for sending impulses and usually many branches (dendrites) for receiving impulses. Normally, nerves transmit impulses electrically in one direction—from the impulse-sending axon of one nerve cell to the impulse-receiving dendrites of the next nerve cell. At contact points between nerve cells (synapses), the axon secretes tiny amounts of chemical messengers called neurotransmitters. Neurotransmitters trigger the receptors on the next nerve cell's dendrites to start up a new electrical current. Different types of nerves use different neurotransmitters to convey impulses across the synapses. The nervous system is an extraordinarily complex communication system that can send and receive voluminous amounts of information simultaneously. However, the system is vulnerable to diseases and injuries. For example, nerves can degenerate, causing Alzheimer's disease or Parkinson's disease. Bacteria or viruses can infect the brain or spinal cord, causing encephalitis or meningitis. A blockage in the blood supply to the brain can cause a stroke. Injuries or tumors can cause structural damage to the brain or spinal cord. AGING’S EFFECTS Brain: Brain function varies normally as people pass from childhood through adulthood to old age. During childhood, the ability to think and reason steadily increases, enabling a child to learn increasingly complex skills. During most of adulthood, brain function is relatively stable. After a certain age, which varies from person to person, brain function declines. Different aspects of brain function are affected at different times. Short-term memory and the ability to learn new material tend to be affected relatively early. Verbal abilities, including vocabulary and word usage, may begin to decline at about age 70. Intellectual performance—the ability to process information (regardless of speed)—is usually maintained until about age 80 if no neurologic disorders are present. Reaction time and performance of tasks may become slower because the brain processes nerve impulses more slowly. However, the effects of aging on brain function may be difficult to separate from the effects of various disorders that are common among older people. These disorders include depression, stroke, an underactive thyroid gland (hypothyroidism), and degenerative brain disorders such as Alzheimer's disease. As people age, the number of nerve cells in the brain usually decreases, although the number lost varies greatly from person to person, depending on the person's health. As the number of nerve cells decreases, new connections are made between remaining nerve cells. These connections may help compensate for the

12. TermeX • Simple Concordance • Collocation Extract

13. TermeX • A tool – collocation extraction • No verb collocations • Frequent nouns

15. Simple Concordance • List of concordances • Separate files • KWIC

16. http://www.textworld.com/scp

18. 410is also used to purify blood by removing harmful 410 or excessive numbers of blood cells or platelets in 410 . To be helpful for purifying blood, hemapheresis must 410 the undesirable substance or blood cell faster than the 411 that are used to purify blood are plasmapheresis and 411 , excess numbers of certain blood cells are removed. 411 (an excess of red blood cells), certain types of 411 leukemia (an excess of white blood cells), and 412 large fluid shifts between blood vessels and tissues that 412 and tissues that occur as blood is removed and returned 413 members or friends can donate blood specifically for one 413 the recipient's and donor's blood types and Rh factors are 413 , knowing who donated the blood is comforting, although 413 one from an unrelated person. Blood from a family member is 415 stem cells rather than whole blood. Prior to the donation 415 into the bloodstream. Whole blood is drawn from the donor, 415 a machine that separates the blood into its components 415 and returns the rest of the blood to the donor./DONATION 417 process of donating whole blood takes about 1 hour. 410is also used to purify blood by removing harmful 410 or excessive numbers of blood cells or platelets in 410 . To be helpful for purifying blood, hemapheresis must 410 the undesirable substance or blood cell faster than the 411 that are used to purify blood are plasmapheresis and 411 , excess numbers of certain blood cells are removed. 411 (an excess of red blood cells), certain types of 411 leukemia (an excess of white blood cells), and 412 large fluid shifts between blood vessels and tissues that 412 and tissues that occur as blood is removed and returned 413 members or friends can donate blood specifically for one 413 the recipient's and donor's blood types and Rh factors are 413 , knowing who donated the blood is comforting, although 413 one from an unrelated person. Blood from a family member is 415 stem cells rather than whole blood. Prior to the donation 415 into the bloodstream. Whole blood is drawn from the donor, 415 a machine that separates the blood into its components 415 and returns the rest of the blood to the donor./DONATION 417 process of donating whole blood takes about 1 hour.

19. Collocation extract • LL and MI • Span, frequency, level of meaning, distance

20. http://collocation-extract.software.informer.com/3.0 • http://collocation-extract.software.informer.com/3.0

21. Table 2. The results of the analysis of ‘Collocation Extract’ tool for the noun ‘diagnosis’

22. Table 3. The most frequent verb collocations in the corpus

23. CONCLUSION • processing a corpus – difficult • 3 different corpus tools • TermeX – blood (6675) • Simple Concordance • Collocation Extract– relieve pain

24. FUTURE RESEARCH • Useful collocations • Dictionary