Showing papers in "Science in 1961"
TL;DR: The relationship between deuterium and oxygen-18 concentrations in natural meteoric waters from many parts of the world has been determined with a mass spectrometer and shows a linear correlation over the entire range for waters which have not undergone excessive evaporation.
Abstract: The relationship between deuterium and oxygen-18 concentrations in natural meteoric waters from many parts of the world has been determined with a mass spectrometer. The isotopic enrichments, relative to ocean water, display a linear correlation over the entire range for waters which have not undergone excessive evaporation.
6,721 citations
TL;DR: A standard, based on the set of ocean water samples used by Epstein and Mayeda to obtain a reference standard for oxygen-18 data, but defined relative to the National Bureau of Standards isotopic reference water sample, is proposed for reporting both deuterium and oxygen- 18 variations in natural watersrelative to the same water.
Abstract: A standard, based on the set of ocean water samples used by Epstein and Mayeda to obtain a reference standard for oxygen-18 data, but defined relative to the National Bureau of Standards isotopic reference water sample, is proposed for reporting both deuterium and oxygen-18 variations in natural waters relative to the same water. The range of absolute concentrations of both isotopes in meteoric-waters is discussed.
1,773 citations
1,227 citations
TL;DR: Four rats were trained to press a lever on a ratio schedule of reinforcement in which the number of lever presses required on each consecutive run increased by a fixed increment.
Abstract: Four rats were trained to press a lever on a ratio schedule of reinforcement in which the number of lever presses required on each consecutive run increased by a fixed increment. Both concentration and volume of the reward were varied. Relationships were obtained between reward and deprivation variables and the size of the final completed ratio run.
1,082 citations
783 citations
TL;DR: Marked polydipsia was produced in all animals trained to press a bar for food pellets on a 1-minute variableinterval schedule and it is suggested that since this feeding arrangement produces a sustained, high fluid intake in the normal, unrestrained animal, it might serve as a useful tool in the study of renal function.
Abstract: Marked polydipsia was produced in all animals trained to press a bar for food pellets on a 1-minute variableinterval schedule. It is suggested that since this feeding arrangement produces a sustained, high fluid intake in the normal, unrestrained animal, it might serve as a useful tool in the study of renal function.
729 citations
667 citations
TL;DR: Actinomycin D inhibits the synthesis of ribonucleic acid in L cells and the yield of vaccinia virus containing deoxyribon nucleic acid, but it does not inhibit cellular de oxygenribonucleics acid synthesis or the multiplication of Mengo virus containing ribonuclear acid.
Abstract: Actinomycin D inhibits the synthesis of ribonucleic acid in L cells and the yield of vaccinia virus containing deoxyribonucleic acid, but it does not inhibit cellular deoxyribonucleic acid synthesis or the multiplication of Mengo virus containing ribonucleic acid. These observations serve to distinguish the replication of viral ribonucleic from ribonucleic acid synthesis which is controlled by viral or cellular deoxyribonucleic acid.
541 citations
TL;DR: The split brain behaves in many respects like two separate brains, providing new research possibilities, according to researchers at the Massachusetts General Hospital.
Abstract: The split brain behaves in many respects like two separate brains, providing new research possibilities.
488 citations
TL;DR: Electrocardiography is proposed to be implemented by the use of long-period, continuous recording of heart potentials with a portable, self-contained instrument together with semiautomatic methods for the rapid analysis of the resulting voluminous data.
Abstract: I have proposed that orthodox electrocardiography be implemented, both for research and medical purposes, by the use of long-period, continuous recording of heart potentials with a portable, self-contained instrument-the electrocardiocorder together with semiautomatic methods for the rapid analysis of the resulting voluminous data. An electronic system to make this concept practical has been developed in our laboratory and typical results are described in this article.
464 citations
TL;DR: X-ray and electron-diffraction examinations prove the existence of diamond in this material and the mechanism proposed for the formation of diamond under these conditions is simple compression in the c-axis direction of the rhombohedral form of graphite.
Abstract: Samples of graphite have been recovered after exposure to explosive shocks of 300,000-atm estimated intensity X-ray and electron-diffraction examinations prove the existence of diamond in this material The mechanism proposed for the formation of diamond under these conditions is simple compression in the c-axis direction of the rhombohedral form of graphite
TL;DR: A rather detailed theory of general anesthesia is formulated, which is described in the following paragraphs as one of the steps in a successful molecular attack on psychobiology.
Abstract: During the last twenty years much
progress has been made in the determination
of the molecular structure of
living organisms and the understanding
of biological phenomena in terms of
the structure of molecules and their
interaction with one another. The progress
that has been made. in the field of
molecular biology during this period
has related in the main to somatic and
genetic aspects of physiology, rather
than to psychic. We may now have
reached the time when a successful
molecular attack on psychobiology, including
the nature of encephalonic
mechanisms, consciousness, memory,
narcosis, sedation, and similar phenomena,
can be initiated. As one of the
steps in this attack I have formulated
a rather detailed theory of general
anesthesia, which is described in the
following paragraphs (1).
TL;DR: The Doppler shift of ultrasound, scattered from moving elements within a stream of blood, is related to the velocity of blood flow and a flowmeter based on this principle was used to record blood flow through intact vessels in dogs.
Abstract: The Doppler shift of ultrasound, scattered from moving elements within a stream of blood, is related to the velocity of blood flow. A flowmeter based on this principle has been constructed and was used to record blood flow through intact vessels in dogs.
TL;DR: Reserpine, amphetamine, imipramine, and chlorpromazine markedly reduced the uptake of circulating H3-norepinephrine by several tissues and elevated the plasma concentration of the H3 -catecholamine.
Abstract: Reserpine, amphetamine, imipramine, and chlorpromazine markedly reduced the uptake of circulating H3-norepinephrine by several tissues and elevated the plasma concentration of the H3-catecholamine.
TL;DR: Large oral doses of individual amino acids were given three or four times daily for periods of 1 week to schizophrenic patients, some of whom were maintained on iproniazid.
Abstract: Large oral doses of individual amino acids were given three or four times daily for periods of 1 week to schizophrenic patients, some of whom were maintained on iproniazid. Marked alterations in behavior in some patients were associated with the administration of l-methionine and of l-tryptophan.
TL;DR: In the rat, chronic treatment with isoproterenol can cause a selective growth of the salivary glands to approximately five times their normal size within 17 days.
Abstract: In the rat, chronic treatment with isoproterenol can cause a selective growth of the salivary glands to approximately five times their normal size within 17 days. This enlargement is principally due to mitotic proliferation and hypertrophy of the parenchymatous cells.
TL;DR: The moving polygonal patterns in dense cultures of Tetrahymena and other ciliates and flagellates look like "Benard cells," but are not due to thermal convection, but seem to be due to a similar dynamic instability that occurs when the energy input is internal and mechanical.
Abstract: The moving polygonal patterns in dense cultures of Tetrahymena and other ciliates and flagellates look like "Benard cells," but are not due to thermal convection. They seem to be due to a similar dynamic instability that occurs when the energy input is internal and mechanical. The high concentration in the patterns may be useful in fertilization.
TL;DR: From chemical analyses of ancient glasses found in Europe, Western Asia, and Africa from roughly the 15th century B.C. until the 12th century A.D., five main compositional categories have become apparent and each of the main categories was prevalent over a wide geographic area for a period of at least several centuries.
Abstract: From chemical analyses of ancient glasses found in Europe, Western Asia, and Africa from roughly the 15th century B.C. until the 12th century A.D., five main compositional categories have become apparent. With the possible exception of lead glasses which are only occasionally encountered in finds from this period, each of the main categories was prevalent over a wide geographic area for a period of at least several centuries. The categories are described in terms of the expected ranges of concentrations of the five elements, magnesium, potassium, manganese, antimony, and lead, which most clearly differentiate the groups.
TL;DR: In the article "Olfactory stimuli in mammalian reproduction," by A. S. Parkes and H. M. Bruce, the acknowledgement (p. 1054, reference 31) should have read: "It is a pleasure to express the authors' thanks to Dr. Dorothy Price for calling their attention to the work of Jan Martan on the supracaudal glands of the guinea pig."
Abstract: In the article "Olfactory stimuli in mammalian reproduction," by A. S. Parkes and H. M. Bruce [ Science 134, 1049 (1961)], the acknowledgement (p. 1054, reference 31) should have read: "It is a pleasure to express our thanks to Dr. Dorothy Price for calling our attention to the work of Jan Martan on the supracaudal glands of the guinea pig. . . ."
TL;DR: A brief review is given of the development of methods for the determination of total body potassium by whole-body scintillation counting and of studies to establish the utility of body potassium as a measure of gross body composition including fat.
Abstract: On the assumption that the potassium content of the lean body mass is constant, it should be possible to estimate fat content in living man from a measurement of potassium-40 activity in the whole-body scintillation counter. A series of such measurements on children and young adults shows good correlations with skin-fold thickness and weight/height ratio as indices of fatness.
TL;DR: Evidence shows that the B blood group locus in chickens, which controls red cell antigens, is associated with tolerance of skin homografts and three other blood groups loci studied did not show this effect.
Abstract: Evidence shows that the B blood group locus in chickens, which controls red cell antigens, is associated with tolerance of skin homografts. Three other blood group loci studied did not show this effect.
TL;DR: The timing of the first meiotic cycle in the young male mouse was established by serial sacrifices and subsequent paraffin sectioning of testis and epididymis, and the highest frequency of any one phase of meiosis was found at days 17 to 19, when 47 percent of the tubules were found to contain late pachytene.
Abstract: The timing of the first meiotic cycle in the young male mouse was established by serial sacrifices and subsequent paraffin sectioning of testis and epididymis. Meiosis commences in mice 8 to 10 days old. The highest frequency of any one phase of meiosis was found at days 17 to 19, when 47 percent of the tubules were found to contain late pachytene.
TL;DR: This work has shown that when an organism can itself impose extinction during fixed-ratio food reinforcement, the duration of the extinction period is a function of the number of responses required for reinforcement.
Abstract: When an organism can itself impose extinction during fixed-ratio food reinforcement, the duration of the extinction period is a function of the number of responses required for reinforcement. Typically, the subject imposes extinction at the start of the usual fixed-ratio run.