astronomy

John McGinness

John McGinness is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand John McGinness rather than just read about it. In short: John Edward McGinness (born November 19, 1943), is an American physicist and physician. McGinness worked in the fields of organic electronics and nanotechnology.

Key takeaways

John McGinness belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect John McGinness to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of John McGinness from memory before moving on to harder problems.

Reference excerpt

John Edward McGinness (born November 19, 1943), is an American physicist and physician. McGinness worked in the fields of organic electronics and nanotechnology.

Education McGinness studied physics at the University of Houston, and after his B.S. in 1966 he received his PhD in Nuclear Physics, Material Science, and Space Science at Rice University in 1970. He received his MD from the University of Texas Health Science Center at Houston (UTHealth) in 1985 and worked in internal medicine for one year, changing to psychiatry and working at the Department of Psychiatry, UTHealth, from 1989 to 1992. He authored roughly 40 research publications, book chapters, and presentations.

Work John McGinness materially contributed to the modern field of organic electronics.

In 1972, while working at the Metallurgy department at Youngstown State University, McGinness suggested that electronic conduction in melanins (polyacetylene, polypyrrole, and polyaniline "blacks" and their copolymers) is analogous to conduction in amorphous solids such as the chalcogenide glasses. This area was originally pioneered by Sir Nevill Mott, among others. That is, it involves such things as mobility gaps, phonon-assisted hopping, polarons, quantum tunneling, and so forth. From Youngstown, McGinness moved to the Physics Department of The University of Texas M. D. Anderson Cancer Center. The department had an interest in the physical properties of melanin as a possible hook to treating melanoma. While of enormous importance now, this area was a research backwater at the time. With the notable exception of Bolto et al., who had reported high conductivity in iodine-doped polypyrrole, few but melanoma researchers had much reason to look at the electronic properties of such rigid-backbone polymer "blacks". This is why the putative first molecular electronic device came from a cancer hospital. The chalcogenide glasses show "switching", in which an applied "threshold voltage" reversibly switches a material from a low-conductivity "OFF" state to a high-conductivity "ON' state. The similarity of conduction mechanisms suggested that the melanins might also demonstrate voltage-controlled switching. Following this lead, McGinness and his MD Anderson coworkers constructed a voltage-controlled switch incorporating melanin as its active element . They also further characterized its electronic behavior. Since he was at a cancer research institute, McGinness' other interests included the role of free radicals in the action and toxicity of the anticancer drugs cisplatin, adriamycin, and bleomycin. He was the first to show that the kidney toxicity of cisplatin involves reactive oxygen species. Some of this work was done with Harry Demopoulos. McGinness was also involved in the dielectric spectroscopy of water bound to membranes. This was related to the future development of magnetic resonance imaging.

References

Further reading John McGinness, Proctor, P.H., Harry Demopoulos, Hokansen, J.A. and Van, N.T. In vivo evidence for superoxide and peroxide production by adriamycin and cis-platinum. In: Pathology of Oxygen. A. Author, (Ed.). Academic Press, New York, 1982, pp. 191–202. McGinness J, Kishimoto A, Hollister LE. Avoiding neurotoxicity with lithium-carbamazepine combinations. Psychopharmacol Bull. 1990;26(2):181-4. McGinness JE, Grossie B Jr, Proctor PH, Benjamin RS, Gulati OP, Hokanson JA. Effect of dose schedule of vitamin E and hydroxethylruticide on intestinal toxicity induced by adriamycin. Physiol Chem Phys Med NMR. 1986;18(1):17-24. McGinness J. A new view of pigmented neurons. J Theor Biol. 1985 Aug 7;115(3):475-6. Gulati OP, Nordmann H, Aellig A, Maignan MF, McGinness J. Protective effects of O-(beta-hydroxyethyl)-rutosides (HR) against adriamycin-induced toxicity in rats. Arch Int Pharmacodyn Ther. 1985 Feb;273(2):323-34. Schrauzer GN, McGinness JE, Ishmael D, Bell LJ. Alcoholism and cancer. I. Effects of long-term exposure to alcohol on spontaneous mammary adenocarcinoma and prolactin levels in C3H/St mice. J Stud Alcohol. 1979 Mar;40(3):240-6. Pietronigro DD, McGinness JE, Koren MJ, Crippa R, Seligman ML, Harry Demopoulos. Spontaneous generation of adriamycin semiquinone radicals at physiologic pH. Physiol Chem Phys. 1979;11(5):405-14. McGinness JE, Crippa PR, Kirkpatrick DS, Proctor PH. Reversible and irreversible changes in hydrogen ion titration curves of melanins. Physiol Chem Phys. 1979;11(3):217-23. Kirkpatrick DS, McGinness JE, Moorhead WD, Corry PM, Proctor PH. High-frequency dielectric spectroscopy of concentrated membrane suspensions. Biophys J. 1978 Oct;24(1):243-5.

External links The Chip Collection - Proctor McGinness Introduction, Smithsonian Institution

Worked examples

Example 1 — a first encounter with John McGinness

Start with the simplest possible case. Write down what John McGinness claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to John McGinness before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about John McGinness ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of John McGinness

In research: John McGinness appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses John McGinness in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: John McGinness is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1943 births, Conductive polymers, Living people, so understanding it makes those chapters shorter.
In everyday life: Look for John McGinness outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study John McGinness in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what John McGinness means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain John McGinness out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is John McGinness in simple terms?

John Edward McGinness (born November 19, 1943), is an American physicist and physician. McGinness worked in the fields of organic electronics and nanotechnology.

Why does John McGinness matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study John McGinness?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on John McGinness.