bluuebunny/crossref_metadata_2025 huggingface dataset:
Escape and Avoidance Learning in Newly Hatched Domestic Chicks
Authors: James H. , Binks Carolyn
Published: October 2006

Under the conditions specified, chicks fail to learn either to escape or to avoid shock on the day of hatching. Chicks trained for the first time on the day after hatching quickly learn to escape but do not learn to avoid shock. Avoidance learning first appears on the third day of life, and from that time the number of chicks learning to avoid increases with age, so that by the fifth day of life the majority are able to do so.
Chlorophyll
a
Appearance in the Dark in Higher Plants: Analytical Notes
Authors: Kupke D. W. , Huntington Judith L.
Published: October 2006

The increase in the ratio [chlorophyll
a
]/[chlorophyll
b
] which occurs in expanding bean leaves in the dark, is a result of chlorophyll
a
formation with a concomitant loss in chlorophyll
b
. The analytical methods for assay of these pigments were examined closely and found to be adequate for this purpose when proper safeguards are taken.
Lactic Dehydrogenases: Subfractionation of Isozymes
Authors: Fritz P. J. , Jacobson K. Bruce
Published: October 2006

Electrophoresis in polyacrylamide gel of homogenates of various organs from the mouse yields five major lactic dehydrogenase bands. If the gels are treated with β-mercaptoethanol, subsequent electrophoresis produces 15 bands which show lactic dehydrogenase activity. This could be explained if one molecule of nicotinamide adenine dinucleotide (coenzyme) is attached to each of the monomeric subunits of lactic dehydrogenase and if mercaptoethanol can remove the coenzyme only from the muscle type. This is consistent with the hypothesis that intact lactic dehydrogenase is a tetramer.
Hormone-Induced Esterase in Mouse Kidney
Authors: Shaw Charles R. , Koen Ann L.
Published: October 2006

Starch-gel electrophoresis of an extract of mouse kidney disclosed that an esterase is present in mature males but absent in females and immature males. When testosterone was injected for 7 days the enzyme could be detected in kidney extracts obtained from both female and young animals. Hence the enzyme may be a hormone-induced one.
Crystal Structures of Titanium, Zirconium, and Hafnium at High Pressures
Authors: Jamieson John C.
Published: October 2006

At high pressures, as determined by x-ray analysis, titanium and zirconium metal have a distorted, body-centered-cubic structure. This phase persists on pressure release. The normal hexagonal close-packed structures are recovered when the metals are heated. An electronic shift must occur in the transition. Hafnium metal showed no such transition.
Ion Exchange at Edge and Interlayer in Montmorillonites Differing in Size
Authors: Jonas Edward C.
Published: October 2006

Titrations of hydrogen-saturated montmorillonite with sodium hydroxide indicate that two kinds of hydrogen are exchanged on the surface of the clay. At low
p
H there is more titratable hydrogen in a fine-size fraction of the clay than there is in a coarse fraction. This indicates neutralization of hydrogen adsorbed at the crystallite edge. The hydrogen adsorbed on the interlayer flake surface is neutralized at a higher
p
H, and there are more titratable hydrogen ions for the coarse fraction than for the fine. This suggests that surface-charge density is a function of crystallite size, a proposal already made on the basis of other properties of clay.
Nonhydrolytic Pathway in Metabolism of
N
-Methylcarbamate Insecticides
Authors: Dorough H. Wyman , Leeling Norman C. , Casida John E.
Published: October 2006

Sevin (1-naphthyl N-methylcarbamate), when metabolized by rat liver microsomes and insects, yielded at least five carbamate metabolites involving modification of both the methyl group and ring. Certain of these metabolites appeared in milk when Sevin was fed to a goat. The metabolism of
o-iso
propoxyphenyl
N
-methylcarbamate by liver microsomes, insects, and plants was compared to that of Sevin.
Homologous Disease Reactivation by X-radiation
Authors: Schwartz Robert S. , Beldotti Lorraine
Published: October 2006

Hybrid
F
1
mice (
BDF
1
) that failed to develop homologous disease after injection of parental (C57 Bl/6) spleen cells were treated with 400 roentgens of total body x-radiation 13 months later. Typical homologous disease promptly developed in these mice. This suggests that parental lymphoid cells may acquire immunologic tolerance to "foreign" host antigens and that the tolerant state is disrupted by sublethal doses of radiation.
Marihuana: Tetrahydrocannabinol and Related Compounds
Authors: Lerner Melvin
Published: October 2006

Marihuana was analyzed for its major constituents, cannabidiolic acid, cannabidiol, tetrahydrocannabinol, and cannabinol, by treating the petroleum ether extract with diazomethane. The methyl esters so produced, together with the unchanged components, were subjected to gas chromatography on a polar silicone column.
Electroencephalographic Responses to Ionizing Radiation
Authors: Garcia J. , Buchwald N. A. , Bach-y-Rita G. , Feder B. H. , Koelling R. A.
Published: October 2006

Electroencephalographic recordings made from chronically implanted cortical electrodes indicate that ionizing radiation has an immediate effect upon brain wave patterns. X-rays delivered at the rate of 0.2 roentgen per second produce an arousal effect resembling that which occurs as a result of stimulation through peripheral receptor systems.
Pattern Vision in Newborn Infants
Authors: Fantz Robert L.
Published: October 2006

Human infants under 5 days of age consistently looked more at black-and-white patterns than at plain colored surfaces, which indicates the innate ability to perceive form.
Histone and DNA in Isolated Nuclei from Chicken Brain, Liver, and Erythrocytes
Authors: Sporn Michael B. , Dingman C. Wesley
Published: October 2006

In isolated brain and liver nuclei the ratio of histone to deoxyribonucleic acid is lower than in nuclei from erthrocytes. Deoxyribonucleoproteins from brain and liver, in contrast to deoxyribonucleoproteins from erythrocytes, are more soluble in isotonic sodium chloride.
Venus: A Map of Its Brightness Temperature
Authors: Murray Bruce C. , Wildey Robert L. , Westphal James A.
Published: October 2006

The 200-inch Hale telescope has been used to make high-resolution maps of the brightness temperature of Venus at wavelengths 8 to 14 microns. Resolution of about 1/30 of the disk reveals a general symmetry about the plane of the orbit, no day-night temperature effects, and a transient temperature anomaly in the southern hemisphere.
Temperature Dependence of Wing Abnormality in
Tribolium confusum
Authors: Slater John V. , Rescigno A. , Amer Nabil M. , Tobias C. A.
Published: October 2006

When
Tribolium confusum
pupae were exposed continuously to temperatures from 10°C to 40°C, the adults which finally emerged exhibited wing abnormalities typical of those obtained with x-irradiation. The data indicate the implication of two processes. Two mathematical models are suggested to account for this phenomenon.
Phytotoxic Substance from a Species of
Penicillium
Authors: Norstadt Fred A. , McCalla T. M.
Published: October 2006

A
Penicillium urticae
Bainer, isolated from subsurface-tilled plots showing reduced wheat growth, produced a phytotoxic substance. The melting point and infrared and ultraviolet spectra of the crystalline material showed this substance to be patulin. Wheat shoot growth inhibition of 50 percent required 20, 20, and 75 parts per million of patulin in solution, sand, and soil culture, respectively.
Homograft Tolerance in Mice: Use of Urethan and Sublethal Irradiation
Authors: Davis W. E. , Cole L. J.
Published: October 2006

Adult mice [CBA/J (H-2
k
)], which received either a single sublethal dose of x-radiation (500 rad) or urethan plus 500 rad, were given intravenous injections of C3H/HeJ (H-2
k
) spleen or bone marrow cells (18 to 42 × 10
6
cells per mouse) or both, for 3 days. C3H/HeJ tail-skin homografts were retained (over 130 days) by these mice, whereas BALB/cJ (H-2
d
) homografts all were rejected within 33 days. Similarly irradiated or urethan-treated controls (or controls treated with a combination of both), which did not receive C3H cells, rejected both homografts. Specific homograft tolerance is induced in adult mice by this procedure.
Angiotensinase with a High Degree of Specificity in Plasma and Red Cells
Authors: Khairallah Philip A. , Bumpus F. Merlin , Page Irvine H. , Smeby Robert R.
Published: October 2006

A peptidase with a high degree of specificity for angiotensin II occurs in normal human plasma and red cells. Preparations from both sources have the same
p
H optimum, require calcium ions, and hydrolyze valyl
5
- or isoleucyl
5
-angiotensin II, but do not hydrolyze β-aspartyl
1
-angiotensin II, arginyl
1
-angiotensin II or deaminoangiotensin II. This enzyme, given the name angiotensinase A, requires α-L-aspartic acid or α-L-asparagine as the
N
-terminal amino acid in its angiotensin substrate, and thus differs from kidney leucine aminopeptidase. Other peptidases known to hydrolyze angiotensin also hydrolyze at least one of the other angiotensin analogs with substitution in the one position.
Lemming Cycle at Baker Lake, Canada, during 1959-62
Authors: Krebs Charles J.
Published: October 2006

Brown and varying lemmings of the central Canadian arctic showed changes in reproduction, mortality, and the properties of the individuals over a 4-year period of fluctuating population. These changes were not due to starvation or malnutrition, nor were there any obvious symptoms of stress. They may have been associated with changes in the behavior of the animals.
Iodine-131 in the Thyroids of North American Deer and Caribou: Comparison after Nuclear Tests
Authors: Hanson W. C. , Whicker F. W. , Dahl A. H.
Published: October 2006

Concentrations of I
131
in the thyroids of deer from Washington, Colorado, and Maryland, and of caribou from Alaska were measured after the resumption of nuclear weapon tests by the U.S.S.R. on 1 September 1961. Maximum concentrations occurred nearly 2 months after the first nuclear test and then decreased at an effective half-time of about 15 days. Thyroids from Washington and Colorado deer showed the highest concentrations, thyroids from Alaskan caribou the lowest.
Water Intake of Normal Children
Authors: Walker John S. , Margolis Frederick J. , Teate H. Luten , Weil Marvin L. , Wilson Howard L.
Published: October 2006

Estimates of daily total fluid intake and of tap-water consumption of normal children were made in four dissimilar geographic areas in the United States. (Total fluid intake increased and, relatively speaking, tap-water consumption decreased, with age.) Of basic importance in fluoridation programs was the observation that even older children rarely drank as much as 500 ml (about 1 pint) of tap water daily.
Analysis of Variance of the Composition of a Migmatite
Authors: Ward Richard F. , Werner Sharon L.
Published: October 2006

To determine the variation of composition in a Front Range migmatite, an analysis of variance (nested design) was run on field measurements. The regional variation is too small to be considered significant, but the areal variation (between outcrops) is large enough to warrant comparison with some other measurable variable such as country rock composition.
Hypoglycemia: A Potent Stimulus to Secretion of Growth Hormone
Authors: Roth Jesse , Glick Seymour M. , Yalow Rosalyn S. , Berson Solomon A.
Published: October 2006

In normal subjects, hypoglycemia produces an abrupt and sustained rise in levels of human growth hormone in plasma. This effect is independent of insulin, glucagon, or epinephrine. Prolonged fasting is accompanied by a rise in the hormone level in plasma. Measurement of this hormone after induced hypoglycemia is a specific test for pituitary somatotropic function.
Ascorbic Acid in the Nutrition of Plant-Feeding Insects
Authors: Vanderzant Erma S. , Richardson Christine D.
Published: October 2006

Bollworms,
Heliothis zea
(Boddie), and salt-marsh caterpillars,
Estigmene acrea
(Drury) gradually decreased in ascorbic acid content as they matured, even in its presence. Cotton leafworms,
Alabama argillacea
(Hübner), also lost ascorbic acid, although a dietary need for the vitamin was not proved. Pink bollworms,
Pectinophora gossypiella
(Saunders), reared without the vitamin, increased in ascorbic acid content as they matured, an indication that the vitamin was synthesized by the insect.
Microfossils in Wisconsinan Loess and Till from Western Illinois and Eastern Iowa
Authors: Jones Robert L. , Hay W. W. , Beavers A. H.
Published: October 2006

Wisconsinan loess from Illinois and Iowa contains a varied assemblage of microfossils including radiolaria, foraminifera, sponge spicules, and opal phytoliths. The foraminifera and radiolaria are derived from Cretaceous rocks occurring on the northern Great Plains. The sponge spicules are from fresh-water sponges living during the epoch of loess deposition. The phytoliths were produced by vegetation growing during deposition. These microfossils are valuable in determining loess and till provenance and in paleoecological reconstruction.
Redundancy in Children's Texts
Authors: Carterette Edward C. , Jones Margaret Hubbard
Published: October 2006

The sequential constraints of pairs of letters were computed for a series of graded readers. Information in single letters is about the same for all texts. Redundancy decreases with increasing grade in a regular way, while mean word length increases. A third reader has about the same redundancy as simple adult text. The constraints in a first reader are considerable, whereas those in a fifth reader approach those in average adult text.
Reversal of Thyroxine-Induced Hypermetabolism by Puromycin
Authors: Weiss William P. , Sokoloff Louis
Published: October 2006

Previous studies have demonstrated that in addition to its effects on metabolic rate, thyroxine stimulates protein biosynthesis. The administration of puromycin, a drug which blocks protein synthesis and, therefore, the thyroxine effect on protein synthesis, acutely reverses the hypermetabolism induced in rats by prior administration of thyroxine and restores the oxygen consumption of the thyrotoxic rats to the euthyroid level. The results suggest that a larger fraction of the total body basal oxygen consumption in hyperthyroidism is related to the process of protein synthesis than in the euthyroid state and that the calorigenic effect of thyroxine is secondary to its effect on protein synthesis.
Radium-226 in Human Diet and Bone
Authors: Hallden Naomi A. , Fisenne Isabel M. , Harley John H.
Published: October 2006

The mean radium-226 content of samples of vertebrae from New York City and San Francisco is 0.032 and 0.026 picocuries of radium-226 per gram of calcium, respectively. The ratio of these two mean values is associated with a similar ratio of radium-226 to calcium found in the diet at the two locations. A plot of the radium-226 content of bone as a function of age indicates that there is no marked difference in levels of bone radium with age.
Thin Membranes of Parlodion
Authors: Lakshminarayanaiah Nallanna , Shanes Abraham M.
Published: October 2006

Parlodion membranes 50 to 1000 Å thick have been prepared by deposition of isoamyl acetate solutions on the air-water interface under conditions of controlled evaporation. Capacitance and resistance measurements have established the integrity of large areas of these membranes. The former also provides corroboration of the thickness estimated from the amounts of parlodion deposited.
Relationship between Nuclear Volumes, Chromosome Numbers, and Relative Radiosensitivities
Authors: Sparrow Arnold H. , Schairer Lloyd A. , Sparrow Rhoda C.
Published: October 2006

An inverse relationship between a volume estimated to be associated with interphase chromosomes and acute lethal exposure to x- or gamma radiation has been found in 16 plant species. The apparent differences in radiosensitivities found would seem spurious, since the estimated average energy absorbed in the nucleus per chromosome (3.6 × 10
6
ev) approaches a constant (variation less than fourfold) in spite of wide ranges of lethal exposures (0.6 to 75 kr), of nuclear volumes (43 to 1758 μ
3
), and of somatic chromosome numbers (6 to 136). The regression line obtained can be used to predict the radiosensitivities of other plant species if their nuclear volumes and chromosome numbers are known.
Hydrogen Ion Incorporation in Crystals
Authors: McConnell Duncan
Published: October 2006

The protons in crystal structures can be related to the oxygen lattice through several spatial arrangements. In orthosilicates (for example, hydrogarnets), so-called tetrahedral hydroxyls have been demonstrated by indirect methods. Similar methods, when applied to kehoeite and viséite, lead to the conclusion that (H
3
O
2
)
-
units can occur in the framework of analcime, a structure in which all apexes of oxygen tetrahedra are shared.
Spontaneous Electrical Activity in the Brains of Diapausing Insects
Authors: Schoonhoven L. M.
Published: October 2006

The spontaneous electrical activity in cerebral ganglia of several insect species does not disappear during diapause. Some recordings of electrical activity in pupae of the cecropia silkworm (in which the brain is considered to be electrically "silent" during diapause) suggest that at least some activity is maintained, but possibly it is restricted to certain regions of the brain.
Gastric Content of Fasted Primates: A Survey
Authors: Brodie David A. , Marshall Richard W.
Published: October 2006

The acidity of the gastric contents of fasted members of seven families of primates was measured, and no relationship was found between acid concentration and phylogenetic development; in general, however, gastric acidity was higher in New World monkeys than in Old World monkeys. The administration of histamine increased gastric acidity.
Genetic Control of Differential Heat Tolerance in Two Strains of the Nematode
Caenorhabditis elegans
Authors: Fatt Helene V. , Dougherty Ellsworth C.
Published: October 2006

Two strains (Bergerac and Bristol) of the nematode
Caenorhabditis elegans
, with different temperature tolerances, were reared axenically at 23 ° to 25°C. The Bergerac strain is heat sensitive (that is, it is sterile at maturity), whereas the Bristol strain is heat resistant (that is, it matures and reproduces normally). Hybrid hermaphrodites (F
1
), produced by crossing Bristol males and Bergerac hermaphrodites, are heat tolerant. Heat sensitivity segregates as a simple Mendelian recessive in the F
2
and F
3
generations.
Conditioned "Anxiety" and Punishment Effects on Operant Behavior of Goldfish (
Carassius auratus
)
Authors: Geller Irving
Published: October 2006

Hungry goldfish learned to press a lever for worms on a 2-minute variable-interval schedule of reinforcement. Lever pressing was suppressed in the presence of a flashing light by (i) pairing the light with a brief electric shock ("anxiety") and (ii) punishing the lever-pressing behavior with electric shocks.
Ginkgophyton
(
Psygmophyllum
) with a Stem of Gymnospermic Structure
Authors: Beck Charles B.
Published: October 2006

A specimen identified as
Ginkgophyton
(
Psygmophyllum
) with a structurally preserved stem of gymnospermic organization has been collected from a late Devonian stratum in New York.
Food versus Perceptual Complexity as Rewards for Rats Previously Subjected to Sensory Deprivation
Authors: Sackett Gene P. , Keith-Lee Patricia , Treat Robert
Published: October 2006

Rats raised in darkness or in a constantly lighted white cage go to food in a T-maze if the food is located in a checkerboard goal. They do not go to food if the food is located in a visually less complex, half-black, half-white goal. Normally raised rats go to food regardless of the visual complexity of the goal.
Thyroid Hormones: Control of Terminal Oxidation
Authors: Bronk J. Ramsey
Published: October 2006

Triiodothyronine administered to thyroidectomized rats preferentially increased the total capacity of the electron transport phosphorylation system when isolated mitochondria from the liver were tested with different substrates, but it caused little increase in the activity of the slowest dehydrogenases and no uncoupling. The increased activity appeared to be partly due to direct activation of some component of the electron transport system, although triiodothyronine injection also stimulated the incorporation of amino acids by isolated mitochondria.
Test of Deutsch's Drive-Decay Theory of Rewarding Self-Stimulation of the Brain
Authors: Pliskoff Stanley S. , Hawkins T. Daryl
Published: October 2006

Deutsch's theory of intracranial self-stimulation generates experimental predictions regarding the effects of both free stimulation of the brain and the pre-extinction training procedure on extinction behavior after rewarding stimulation of the brain. The results of one experiment confirmed the prediction regarding free stimulation; the other experiment did not provide the expected result. We concluded that Deutsch's theory, in its present form, is of restricted generality.
Acetophenazine and Fighting Behavior in Mice
Authors: Knight W. Rea , Holtz John R. , Sprogis George R.
Published: October 2006

Assuming fear to be a variable of importance in the inhibition of aggressive behavior, we used acetophenazine to try to facilitate fighting in mature male C57BL mice. Drugged pairs did not differ significantly from controls in fighting latency; however, the time lapse from the first fight to submission and the actual fighting time to submission were significantly longer for drugged pairs. An attempt is made to relate what is known of the action of the drug with research on the neural correlates of aggressive behavior.
Bradykinin: Vascular Relaxant, Cardiac Stimulant
Authors: Montague Drogo , Rosas Ramon , Bohr David F.
Published: October 2006

Bradykinin infusion causes an increase in cardiac output in rats whether the autonomic nervous system is blocked or not. After autonomic blockade, bradykinin causes a lesser decrease in the total peripheral resistance but a greater increase in cardiac output, resulting in an elevation of arterial pressure. The increase in cardiac output is caused by a small increase in heart rate and a substantial increase in stroke volume. The fact that these increases are observed after autonomic blockade suggests that bradykinin increases cardiac output by direct stimulation of the heart.
Pulmonary Edema as a Consequence of Hypothalamic Lesions in Rats
Authors: Reynolds Robert W.
Published: October 2006

Rats were observed for the incidence of pulmonary edema after the placement of hypothalamic lesions by radio frequency thermocoagulation or d-c electrolysis. In the animals with electrolytic lesions, 31 percent died with pulmonary edema and marked signs were observed in another 20 percent. Moderate transient signs appeared in only 3.7 percent of the animals with radio-frequency lesions, and there were no deaths attributable to this syndrome in this group. These results suggest that this syndrome is an irritative consequence of the electrolytic lesion process rather than a "release" phenomenon.
Volume Changes of a Thixotropic, Sodium Bentonite Suspension during Sol-Gel-Sol Transition
Authors: Anderson Duwayne M. , Leaming George F. , Sposito Garrison
Published: October 2006

Dilatometric measurements during the sol-gel-sol transition of an air-free, thixotropic, sodium bentonite suspension revealed a reversible change in volume of about 2.4 × 10
-4
percent. The volume of the suspension increased during gelation and decreased when the gel was subsequently liquified. This is taken as evidence of a progressive building up, during gelation, of a water structure less dense than normal.
Emerged Holocene South American Shorelines
Authors: Richards Horace G. , Broecker Wallace
Published: October 2006

A pelecypod from the Salina beds of northern Peru at elevation 4.5 m (15 ft) shows a date of about 3000 years B. P., while a gastropod from elevation 22.5 m (75 ft) was older than 30,000 years B. P. A pelecypod from the island of Tierrabomba, near Cartagena, Colombia, at elevation 2.7 m (9 ft) gave a date of about 2850 years, while a pelecypod from Comodoro Rividavia, Argentina, at elevation 9 m (30 ft) gave a date of 5350 years B. P.
Growth of Single Plant Cells
Authors: Gibbs Joy L. , Dougall D. K.
Published: October 2006

Suspension of plant cells from tissue cultures have been plated in nutrient agar medium so that practically all of the individual cells yielded colonies.
Low-Latitude Noctilucent Cloud of 15 June 1963
Authors: Meinel Aden B. , Middlehurst Barbara , Whitaker Ewen
Published: October 2006

A bright noctilucent cloud was observed and photographed northwest of Tucson on 15 June 1963. Results of computations indicate that the cloud was at a height of 71 kilometers. The cloud appears to have resulted from the launching of a Scout space vehicle.
Development of Complete Homozygotes of Tobacco
Authors: Stokes G. W.
Published: October 2006

True homozygotes of
Nicotiana tabacum
L., herein referred to as Ky Iso lines, are being developed from haploids. A technique is described whereby seedlings resulting from fertilization are eliminated, leaving only suspect haploids. After confirmation, haploids are treated to double the chromosomes and these result in completely homozygous plants. One complete homozygote, Ky Iso 1 Ky 16, has been developed and shows extreme uniformity in all characters studied. The Ky Iso lines will be useful in genetic studies that require no plant-to-plant genotypic variability. The Ky Iso lines will be made available upon request as they are developed.
Ribosomal RNA in the Developing Chick Embryo
Authors: Lerner A. Martin , Bell Eugene , Darnell James E.
Published: October 2006

Developing chick embryos from the stage of primitive-streak formation make ribosomal (28
S
and 16
S
) RNA. The size and composition of the RNA appears to be constant throughout the first 7 days of development.
Circulating Small Lymphocytes: Immunologically Competent Cells with Limited Reactivities
Authors: Vredevoe Donna L. , Hildemann W. H.
Published: October 2006

Highly purified small lymphocytes from peripheral blood are capable of producing acute transplantation disease. However, such lymphocytes do not transfer from sensitized to normal mice the capacity to produce antibody to bovine serum albumin under conditions where mixed populations of lymphoid cells from the sensitized donors are effective.
Isolated Mammalian Eye: A Method for Quantitative Evaluation of Autonomic Drugs
Authors: Beaver William T.
Published: October 2006

The enucleated rodent eye can be mounted for study in vitro, in a chamber that contains electrodes suitably placed to enable the severed postganglionic nerves to the iris to be stimulated. The technique provides a simple quantitative method for the study of drugs which act at the parasympathetic neuro-effector junction.
Phosphate Incorporation in Desheathed Nerves: Effects of Potassium and Calcium Ions
Authors: Abood L. G. , Koyama I.
Published: October 2006

In the presence of Ringer's solution containing a high concentration of potassium ions, the incorporation of P
32
-orthophosphate into adenosine triphosphate and other organophosphates of the desheathed sciatic nerve of the bullfrog was inhibited by more than 75 percent. In calcium-free Ringer's solution containing ethylenediaminetetraacetic acid, the inhibition was about 30 percent. Both solutions depolarized the nerves, and the depolarization probably interfered with the mechanisms of phosphate transfer rather than directly with phosphorylation. The inhibition may have been a consequence of the decreased adsorption of phosphates which occurs at the excitable surface during depolarization.
Angiotensin II: Its Effects on Corticoid Production by Chicken Adrenals in vitro
Authors: deRoos Roger , deRoos Carolyn C.
Published: October 2006

Mammalian angiotensin II, added to the incubation medium, failed to increase corticoid production by chicken adrenal tissue in vitro. Mammalian corticotropic hormone (ACTH) stimulated both aldosterone and corticosterone production.
From Molecules to Cells: Imaging Soft Samples with the Atomic Force Microscope
Authors: Radmacher M. , Tillmann R. W. , Fritz M. , Gaub H. E.
Published: October 2006

Since its invention a few years ago, the atomic force microscope has become one of the most widely used near-field microscopes. Surfaces of hard samples are imaged routinely with atomic resolution. Soft samples, however, remain challenging. An overview is presented on the application of atomic force microscopy to organic samples ranging from thin ordered films at molecular resolution to living cells. Fundamental mechanisms of the image formation are discussed, and novel imaging modes are introduced that exploit different aspects of the tip-sample interaction for local measurements of the micromechanical properties of the sample. As examples, images of Langmuir-Blodgett films, which map the local viscoelasticity as well as the friction coefficient, are presented.
Measurement of Quantum Tunneling Between Chiral Isomers of the Cyclic Water Trimer
Authors: Pugliano N. , Saykally R. J.
Published: October 2006

A detailed experimental study of the water trimer is reported. A vibration-rotation-tunneling band of the perdeuterated cluster has been measured near 89.6 wavenumbers by tunable far infrared laser absorption spectroscopy. The data indicate a chiral six-membered ring structure with rapid quantum tunneling occurring between the enantiomers. The observed vibration involves torsional motion of the water subunits about each hydrogen bond axis. It is speculated that larger water clusters would also exhibit transient chirality and that similar effects may be found in liquid water.
Multiple Zinc Finger Forms Resulting from Developmentally Regulated Alternative Splicing of a Transcription Factor Gene
Authors: Hsu Tien , Gogos Joseph A. , Kirsh Susan A. , Kafatos Fotis C.
Published: October 2006

Transcripts encoding the
Drosophila
putative transcription factor CF2 are subject to developmentally regulated alternative splicing, and they encode protein isoforms that differ in the number of zinc fingers. One testis-specific RNA encodes an isoform that includes three zinc fingers and a frame-shifted segment. Two other transcripts encode isoforms with six and seven zinc fingers which bind to distinct promoters and DNA target sequences. Thus, because of alternative splicing, a single gene appears to encode distinct DNA-binding proteins, each capable of regulating different gene sets in different tissues and developmental periods.
Prevention of Programmed Cell Death of Sympathetic Neurons by the
bcl-2
Proto-Oncogene
Authors: Garcia Irène , Martinou Isabelle , Tsujimoto Yoshihide , Martinou Jean-Claude
Published: October 2006

Approximately half of the neurons produced during embryogenesis normally die before adulthood. Although target-derived neurotrophic factors are known to be major determinants of programmed cell death—apoptosis—the molecular mechanisms by which trophic factors interfere with cell death regulation are largely unknown. Overexpression of the
bcl-2
proto-oncogene in cultured sympathetic neurons has now been shown to prevent apoptosis normally induced by deprivation of nerve growth factor. This finding, together with the previous demonstration of
bcl-2
expression in the nervous system, suggests that the Bcl-2 protein may be a major mediator of the effects of neurotrophic factors on neuronal survival.
Absorption Spectra of the Hybrid Pigments Responsible for Anomalous Color Vision
Authors: Merbs Shannath L. , Nathans Jeremy
Published: October 2006

Unequal homologous recombination events between green and red cone pigment genes produce the red-green or green-red hybrid pigment genes found in many individuals with variant color vision. Photobleaching difference absorption spectroscopy of hybrid pigments produced in cultured cells shows that the spectral sensitivity of each hybrid pigment is intermediate between the parental green and red pigment sensitivities. Amino acids encoded by exons 2, 3, 4, and 5 produce spectral shifts at the wavelength of maximal absorbance of 0 to 4, 0 to 4, 3 to 4, and 15 to 21 nanometers, respectively, the exact value depending on the identities of amino acids elsewhere in the hybrid.
Diversity Flourishes in Japan's Research Labs
Authors: Anderson Alun , Hamilton David P. , Myers Fred
Published: October 2006

Japan may look homogenous but the pace of change has actually created a people of extraordinary diversity. Scientists educated before the war at the elite "Imperial" universities are different from those born a few years later; those who experienced postwar poverty are not the same as those born into riches a little later; researchers in wealthy industrial labs see the world differently from their poorer colleagues at the universities; and scientists who have lived abroad for a long while change their perceptions for ever. Below,
Science
talks to Japanese scientists of different ages and different experiences in a wide variety of disciplines: Among them are a Nobel Prize—winner, an ex-student radical, one of Japan's most powerful scientific leaders, an eccentric genius—and some older people who remember Japan's problems and younger people who see Japan's opportunities.
Gravity and Magnetic Anomalies of the Sierra Madera, Texas, "Dome"
Authors: Van Lopik Jack R. , Geyer Richard A.
Published: October 2006

A geophysical traverse across the Sierra Madera "Dome" indicates a negative gravity anomaly of 1½ milligals over the zone of brecciation in the center and a residual positive anomaly of ½ milligal associated with a positive magnetic anomaly of 25 × 10
-5
oersted to the southeast of the zone of brecciation. Areal surveys are needed before any definite conclusions can be drawn concerning the origin of Sierra Madera. However, gravity and magnetic data can be extremely valuable in establishing criteria for classifying terrestrial and lunar features according to meteoritic and cryptovolcanic origin.
Visual Responses in the Eye of the Dragon Fly
Authors: Fuortes M. G. F.
Published: October 2006

Responses to illumination recorded from cells in the eye of the dragonfly are similar to responses of cells in the eye of
Limulus
and are affected in the same manner by currents through the cell membrane. It appears probable that visual responses are brought about by the same processes in the two species.
Estrogen-Induced 16-Hydroxysteroid Dehydrogenase Activity in Rat Kidney
Authors: Ryan Kenneth J. , Meigs Robert A. , Petro Zoltan , Morrison Glenn
Published: October 2006

The activity of an enzyme system which readily converts estriol to 16-ketoestradiol is present only in the kidneys of mature female rats and is absent in the kidneys of male rats and immature rats of either sex. The full enzyme activity occurs in kidneys of rats of either sex at any stage of maturity after administration of estradiol for 2 weeks. The time course of the appearance and disappearance of the enzyme, the absence of detectable inhibitors and activators, and evaluation of cofactor requirements suggest that this may be an example of enzyme induction by the hormone. Furthermore, the enzyme activity itself represents a metabolic pathway for estriol metabolism whose potential quantitative significance has not heretofore been recognized.
Malate Dehydrogenase: Multiple Forms in Separated Blastomeres of Sea Urchin Embryos
Authors: Moore Richard O. , Villee Claude A.
Published: October 2006

Sea urchin embryos at the 64-cell stage were dissociated by treatment with trypsin and separated by centrifugation on a sucrose gradient. The large blastomeres have two and the small blastomeres have three bands of L-malate dehydrogenase activity, which are separated by disk microelectrophoresis on polyacrylamide gel, whereas unfertilized eggs have five.
Inhibition by 5-Iododeoxyuridine of the Oncogenic Effects of Adenovirus Type 12 in Hamsters
Authors: Huebner R. J. , Lane W. T. , Welch A. D. , Calabresi P. , McCollum R. W. , Prusoff W. H.
Published: October 2006

Subcutaneous tumors induced in newborn hamsters by type 12 adenovirus were suppressed when 0.5 mg of 5-iodo-2′-deoxyuridine (IUdR) was given at the same subcutaneous site as the virus. Although one injection of IUdR given immediately after the virus was effective, additional injections on subsequent days reduced further the number of hamsters developing tumors. These effects of IUdR are especially interesting since replication of infectious adenovirus 12 cannot be demonstrated in the hamsters at any time before or after tumor development.
Thymus: Its Limited Role in the Recovery of Homograft Response in Irradiated Mice
Authors: Tyan Marvin L. , Cole Leonard J. , Davis William E.
Published: October 2006

Adult mice subjected to thymectomy or sham thymectomy received lethal irradiation and subsequent protective infusion of syngeneic bone marrow. Thirty days later they received allogeneic and xenogeneic skin grafts. Donors of the xenogeneic grafts were rats. The thymectomized mice rejected the grafts of rat skin only slightly later than the controls did; in contrast, the time of retention of allogeneic grafts was significantly longer in the thymectomized mice.
Glycogen-Containing Cells of Estrogen-Induced Renal Tumors of the Hamster
Authors: Arcadi John A.
Published: October 2006

Cells which contain glycogen, and which may arise from the connective tissue matrix, can be demonstrated in the estrogen-induced renal tumor of the hamster when the tumor tissue used has either been lyophilized or frozen and then substituted in absolute alcohol containing mercuric chloride. Glycogen has not been found previously in this type of tumor. Studies of the role of glycogen in this type of neoplasm may elucidate mechanisms of tumorigenesis.
Complementary Strand Association between Nucleic Acids and Nucleic Acid Gels
Authors: Britten R. J.
Published: October 2006

Nucleic acid gels can be formed as a result of the cross-linking action of ultraviolet light or of nitrous acid. Such gels form duplex combinations with complementary nucleic acid strands.
Molar Size Sequences and Fossil Taxonomy
Authors: Lewis Arthur B. , Kerewsky Rose S.
Published: October 2006

Although relative molar size has been considered a major taxonomic criterion, separating the Australopithecines and some erectus fossils from sapiens man, the M
2
> M
1
, or "fossil" size sequence is found in 33 percent of Ohio whites and Pima Indians, yet is not necessarily the major sequence in the chimpanzee.
Proteinpolysaccharide in Connective Tissue: Inhibition of Phase Separation
Authors: Weinstein Harry , Sachs Coleman R. , Schubert Maxwell
Published: October 2006

A macromolecule of protein and chondroitin sulfate (PP-L) inhibits sedimentation of barium-polystyrene sulfonate (BaPSS) and of calcium phosphate at low but not at high values of gravity. Sedimentation of BaPSS removes a large fraction of PP-L from solution, but sedimentation of calcium phosphate does not. The results suggest entanglement among linear polyanionic chains.
Contamination of Commercial Rabbit Albumin Preparations by Bovine Albumin
Authors: Linscott William D.
Published: October 2006

Seven commercial rabbit serum albumin preparations obtained from two different sources were found to contain bovine serum albumin. The extent of contamination in three representative samples varied from 0.35 to 0.54 percent.
Persistent Mitosis of Transfused Homologous Leukocytes in Children Receiving Antileukemic Therapy
Authors: Levin Robert H. , Whang Jacqueline , Tjio J. H. , Carbone Paul P. , Frei Emil , Freireich Emil J.
Published: October 2006

Temporary homologous bone marrow grafts were observed in three patients with acute leukemia, receiving intensive antileukemic treatment, following transfusion of peripheral blood cells from donors with chronic myelocytic leukemia. Persistent mitosis of the transfused cells, containing the Philadelphia chromosome marker, were detected by cytogenetic techniques 19, 39, and 52 days after transfusion.
Blood Pressure Changes during Human Sleep
Authors: Snyder Frederick , Hobson J. Allan , Goldfrank Frederick
Published: October 2006

Systolic blood pressure measurements were made on normal human subjects throughout entire nights of natural sleep and were correlated with cyclical changes in electroencephalographic patterns. During the recurrent rapid-eye-movement phase of sleep mean blood pressure levels were found to be generally higher, and the minute-to-minute variability of level was much greater than during the remainder of sleep.
Fresh Water: Temperature of Maximum Density Calculated from Compressibility
Authors: Eklund Henning
Published: October 2006

Measurement of sonic velocities in water provides an accurate method for determining the equation of state for water. A simple equation of state for fresh water yields the temperature of maximum density as a function of pressure.
Tautomerism and Protonation of Guanosine
Authors: Miles H. Todd , Howard Frank B. , Frazier Joe
Published: October 2006

Guanosine has been demonstrated, by infrared and nuclear magnetic resonance spectroscopy, to have a keto-amino structure in neutral aqueous solution and to undergo protonation at N
7
in acid solution.
Inhibition of Growth of Chick Embryo by Inhibition of Deoxycytidylate Deaminase
Authors: Roth Jay S. , Buccino G. , Klein N. W.
Published: October 2006

Deoxyguanylate when added to chick embryos grown in explant inhibited growth and development. Deoxycytidylate deaminase activity was inhibited both in the explants and in vitro; since the effect was quite specific, it is suggested that this may represent another control mechanism for deoxynucleotide synthesis.
Actinomycin D: Its Effect on Antibody Formation in vitro
Authors: Uhr Jonathan W.
Published: October 2006

The formation of antibodies to bacteriophage T
2
in vitro was inhibited by 5 × 10
-8
M
actinomycin D. This result is consistent with the concept that antibody formation depends upon DNA-dependent RNA synthesis.
Toxin-Producing
Aspergillus
Isolated from Domestic Peanuts
Authors: Diener U. L. , Davis N. D. , Salmon W. D. , Prickett C. O.
Published: October 2006

Nine species of fungi isolated from stored domestic peanuts were grown in the laboratory on sterilized peanuts and were incorporated into diets fed to ducklings. Symptoms of acute toxicity resulted only after consumption of one of the diets and this one contained material incubated with the fungus,
Aspergillus flavus
Link ex Fries.
Tautomerism and Site of Protonation of 1-Methylcytosine: Proof by Nuclear Magnetic Resonance Spin-Spin Coupling
Authors: Miles H. Todd , Bradley Robert B. , Becker Edwin D.
Published: October 2006

New nuclear magnetic resonance data lead to a completely unambiguous proof that the predominant tautomeric form of 1-methylcytosine is the amino form and that in acid solution the molecule protonates at 3-N. The close similarity of the nuclear magnetic resonance spectra of this compound to the spectra of the cytosine nucleosides indicates that these structures also exist in the nucleosides. These conclusions are reached on the basis of the spectra of analogs labeled with N
15
and of the proton spin decoupling measurements made at low temperature.
Nitrogen and Potassium Effect on the Color of Red Roses
Authors: Lindstrom R. S. , Markakis P.
Published: October 2006

Variable coloration was displayed by
Rosa hybrid
, var. Better Times, grown in solutions of various concentrations of nitrogen and potassium. As revealed by measuring the color in Hunter values, growth in high potassium and low nitrogen concentrations resulted in less reddish and more bluish roses, while cultivation in a low nitrogen concentration, irrespective of the N/K ratio, resulted in roses which were more lightly colored than those grown in high concentrations of nitrogen and potassium. The results were statistically significant at the 1 percent probability level.
New Papovavirus Contaminating Shope Papillomata
Authors: Hartley Janet W. , Rowe Wallace P.
Published: October 2006

A virus having the characteristics of the papovaviruses was isolated from several naturally occurring cottontail papillomata. Serologic and animal inoculation studies indicate that it is not Shope papilloma virus, but a previously undescribed, nonpathogenic agent of cottontail rabbits.
Swamp Mosquito,
Culiseta melanura
: Occurrence in an Urban Habitat
Authors: Spielman Andrew
Published: October 2006

Adult
Culiseta melanura
were collected in Boston during three consecutive years (1961-63). Breeding sites were found along the bank of an impounded stream and in a small water collection in a concrete-lined pit.
Cesium in Liriodendron and Other Woody Species: Organic Bonding Sites
Authors: Brown Gregory N.
Published: October 2006

In trees labeled with cesium-137, the isotope in the sap streams is primarily in the free ionic form. Much ionic Cs
137
also appears to occur in intracellular fluids other than the sap streams. However, a small quantity of Cs
137
forms ionic bonds with organic compounds (probably as salts of carboxylic acids). Even though most of the activity appears in the phloem tissue, some activity is dispersed in much of the sapwood and even in the dead xylem tissue of the heartwood. Some of this Cs
137
is retained, at least temporarily, by the numerous carboxylic groups of the natural plant compounds of cell walls, cytoplasm of living cells, and cell debris of heartwood.
Circadian Periodicity in the Concentration of Prolactin in the Rat Hypophysis
Authors: Clark Ray H. , Baker Burton L.
Published: October 2006

Prolactin activity in the hypophyses of rats maintained under standardized conditions was assayed in pigeons. The concentration of prolactin in the gland exhibited a circadian rhythm.
Relative Contributions of Uranium, Thorium, and Potassium to Heat Production in the Earth
Authors: Wasserburg G. J. , MacDonald Gordon J. F. , Hoyle F. , Fowler William A.
Published: October 2006

Data from a wide variety of igneous rock types show that the ratio of potassium to uranium is approximately 1 × 10
4
. This suggests that the value of K/U ≈ 1 × 10
4
is characteristic of terrestrial materials and is distinct from the value of 8 × 10
4
found in chondrites. In a model earth with K/U ≈ 10
4
, uranium and thorium are the dominant sources of radioactive heat at the present time. This will permit the average terrestrial concentrations of uranium and thorium to be 2 to 4.7 times higher than that observed in chondrites. The resulting models of the terrestrial heat production will be considerably different from those for chondritic heat production because of the longer half-life of U
238
and Th
232
compared with K
40
Phase Separation in Suspensions Flowing through Bifurcations: A Simplified Hemodynamic Model
Authors: Bugliarello George , Hsiao George C. C.
Published: October 2006

In the laminar flow of a suspension of neutrally buoyant spheres through a bifurcation, intended as a simplified macroscopic model of the flow of blood, the concentration in the side branch is generally lower than in the main branch, and is affected primarily by the ratio of discharges in the two branches, the concentration upstream, and by the branch size.
Growth Inhibition of Sarcoma and Carcinoma Cells of Homozygous Origin
Authors: Hellström K. E.
Published: October 2006

Three sarcomas and one carcinoma, originating in homozygous mice, were tested for growth in isologous animals and various semi-isologous F
1
hybrids after inoculation of 10
3
to 10
5
cells. Findings indicated the existence of an "F
1
hybrid effect" for sarcomas and carcinomas, as previously described for lymphomas and normal hematopoietic cells, there being a lower tumor frequency and a longer latency period in the hybrids than in isologous mice.
Cystinuria: In vitro Demonstration of an Intestinal Transport Defect
Authors: Thier Samuel , Fox Maurice , Segal Stanton , Rosenberg Leon E.
Published: October 2006

A defect in the transport of L-cystine and L-lysine has been found in the intestinal mucosa of patients with cystinuria. Transport studies in normal intestinal mucosa, in contrast to similar studies in the kidney, show that cystine and lysine are mutually inhibitory.