astronomy

John Halver

John Halver 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 Halver rather than just read about it. In short: John Emil Halver (April 21, 1922 – October 24, 2012) was an American biochemist known for his research into the nutritional biochemistry, physiology, and cellular biochemistry of fish. His work on the nutritional needs of fish led to modern methods of fish farming and fish feed production around the world.

Key takeaways

John Halver 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 Halver to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of John Halver from memory before moving on to harder problems.

Reference excerpt

John Emil Halver (April 21, 1922 – October 24, 2012) was an American biochemist known for his research into the nutritional biochemistry, physiology, and cellular biochemistry of fish. His work on the nutritional needs of fish led to modern methods of fish farming and fish feed production around the world. He held a position with the United States Fish and Wildlife Service as director of the Western Fish Nutrition Laboratory in Cook, Washington, where Halver and his staff carried out research on the nutrient requirements for Pacific salmon.

Early life and education Halver received his bachelor's degree in chemistry and a master's in organic chemistry from Washington State University, completing his thesis, *Enzymatic Resolution of Amino Acid Phenyl Hydrazides" in 1948. His Ph.D. is in medical biochemistry, and was awarded by the University of Washington Medical School based on his thesis, *A vitamin test diet for chinook salmon: the water-soluble vitamin requirement of chinook salmon" in 1953. He served as a US Army Ranger, European Theatre during WWII; Platoon Leader to captain, 100th Division, 399 Infantry, Fox Company. Citations received: Croix d’Valeur (France), Purple Heart, Presidential Unit Citation, American Theatre Service Medal, European-African-Middle Eastern Service Medal with two Bronze Stars, World War II Victory Medal, Combat Infantry Badge, Army of Occupation (Germany), and the Citoyen d’Honneur (France). He served in three campaigns: Southern France, The Rhineland, and Southern Germany.

Career In addition to research, Halver taught at the University of Washington. Some of his students have become directors of federal fisheries programs, feed manufacturing plants, and university aquaculture programs. He was named Senior Scientist in Nutrition in 1975 and was US Science Ambassador 1975–1992. In 2005, Halver was named as one of the "Leading Scientists of the World" by the International Biographical Centre of Cambridge, England., because of his work for the Food and Agricultural Organization of the United Nations, the United Nations Development Program, the World Bank, the United States Agency for International Development, and the International Executive Service Corps, which led to improved food supply for populations in developing countries.

Research Halver discovered the cause of trout hepatomas (liver cancer) in the early 1960s, and developed methods of avoiding them. He was voted into the National Academy of Sciences in 1978 on the basis of that work.

Selected publications Fish Feed Technology. J. E. Halver, Ed. 395 Pgs. ADCP/REP/80/11. FAO; Rome, Italy. 1980 Metabolism of Ascorbic Acid and Ascorbic-2-sulfate in Man and the subhuman primate. E. M. Baker, J. E. Halver, D.O.Johnsen, B.E.Joyce, M.K.Knight, and B. M. Tolbert. Annuals of the New York Academy of Sciences. 258: 72-80 1975 Aflatoxicosis and Trout Hepatoma. John E Halver pp265–306 in Aflatoxin, L.A. Goldblatt, ed. Academic Press, NY Special Methods in Pond Fish Husbandry. L. Horvath, G. Tamas, and I. Tolg. (J. E. Halver, Ed.) Akademiai Kaido; Budapest, Hungary. 150 pgs. 1985 Investigation on nutrition of some cultivable finfish species and development of cost-effective formulae feeds. A.K. Jafree and J.E. Halver. ICAR-USDA IN-AES-251. pgs 93. 1991 Nutrient requirements and metabolism of marine species. in Halver, J.E. (C. S. Lee, editor). Aquaculture: Retrospective and Outlook. - An Aquaculture Summit. Asian Fisheries Society, Manila, Philippines and World Aquaculture Society, Baton Rouge, Louisiana, USA. P.117-132 Separation of three commercial forms of Vitamin C (L-ascorbic acid, Ascorbic-2-sulfate, and Ascorbic-2-polyphosphate) by HPLC. S. Felton and J. E. Halver. Proceedings of the Society for Experimental Biology & Medicine. 190: 217–218. (1989) L-Ascorbyl-2-Sulfate alleviates Atlantic Salmon scurvy. J. E. Halver and R. W. Hardy. Proceedings of the Society for Experimental Biology & Medicine 206: 421–424. 1994 Efficacy of L-ascorbyl-2-sulfate as a Vitamin C source for Rainbow Trout. Proceedings of the IV International Symposium on Fish Nutrition and Feeding held June 1991 in Biarritz, France. J. E. Halver, S. Felton, A. Palmisano. p 137–147 in Fish Nutrition in Practice ( S. J. Kaushik and P Luquet, Eds.) INRA; Paris, France. 1992 Effects of dietary Omega-3 polyunsaturated fatty acids on brain gene expression. Kitajka, Klara; Sinclair, Andrew J; Weisinger, Richard S; Weisinger, Harrison S; Mathai, Michael; Jayasooriya, Anura P; Halver, JE; Puskas, Laszlo G. Proc. Natl. Acad. Sci. USA 101:10931-10936 (2004) A vitamin test diet for long-term feeding studies. J. E. Halver and J. A. Coates. Progressive Fish-Culturist. 19: 112–118. 1957 Nutrition of Salmonoid Fishes, IV. An amino acid test diet for Chinook Salmon. J. E. Halver. Journal of Nutrition. 62: 245–254. 1957

Personal life Halver was an active Christian, and gave lectures on the harmony between science and theology, At the time of his death Halver was married to Jane Loren Halver (his wife of 68 years) and had 5 children: John Emil IV, Nancylee, Janet, Peter, and Deborah, 12 grandchildren, and 4 great-grandchildren.

References

Illustrations

Worked examples

Example 1 — a first encounter with John Halver

Start with the simplest possible case. Write down what John Halver 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 Halver 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 Halver 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 Halver

In research: John Halver 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 Halver 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 Halver is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1922 births, 2012 deaths, 20th-century American zoologists, so understanding it makes those chapters shorter.
In everyday life: Look for John Halver 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “John Halver” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study John Halver in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what John Halver 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 Halver out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is John Halver in simple terms?

Why does John Halver 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 Halver?

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 Halver.