bluuebunny/crossref_metadata_2025 huggingface dataset:
Strengthening the Basis of National Security
Authors:   Board of Directors of the American Association for the Advancement of Science
Published: October 2006

Those charged with safeguarding the United States have sought to minimize the danger of internal subversion through the screening of government employees and persons having access to classified information. This program is necessary, but it poses a serious dilemma: the more completely we succeed in reducing the danger that information now in our possession may leak to a potential enemy, the more risk we run of interfering with scientific progress and of reducing the technologic superiority and the moral and physical strength upon which victory in the ultimate test would depend. The inherent dangers of this dilemma can be lessoned and our strength enhanced by changing our basic concept of internal security from one that attempts almost exclusively to minimize our losses to one that places greatly increased emphasis on maximizing our gains.
Reaction of Monosaccharides with Proteins: Possible Evolutionary Significance
Authors: Bunn H. Franklin , Higgins Paul J.
Published: October 2006

Measurements were made of the rate of condensation of various monosaccharides with amino groups of hemoglobin to form Schiff base linkages. The reactivity of each sugar was dependent on the extent to which it exists in the open (carbonyl) structure rather than in the ring (hemiacetal or hemiketal) structure. Among the 15 monosaccharides tested, aldoses showed higher reactivities than ketoses. Glucose was the least reactive of the aldohexoses. The emergence of glucose as the primary metabolic fuel may be due in part to the high stability of its ring structure which limits potentially deleterious nonenzymatic glycosylation of proteins.
Infectious Etiology of Neuritic (Senile) Plaques in Mice
Authors: Wiśniewski Henryk M. , Bruce Moira E. , Fraser Hugh
Published: October 2006

Brains of inbred female VM mice infected with scrapie agent were studied with the use of the Bodian silver impregnation method and by electron microscopy. In brains affected with scrapie, after an incubation period of between 587 and 655 days, numerous primitive, classical, and amyloid plaques were found. No plaques of any type were seen in the control mice.
Premature Specification of the Retina in Embryonic
Xenopus
Eyes Treated with Ionophore X537A
Authors: Jacobson Marcus
Published: October 2006

Eyes excised from
Xenopus
embryos at stages 24 to 25 were cultured for 4 to 6 hours in a medium containing the ionophore X537A or in a control medium. The eyes were implanted either upside down or normally in host embryos at stages 28 to 30, and their retinotectal projections were mapped after metamorphosis. Treatment with X537A prevented realignment of retinal axes in eyes implanted into hosts that were capable of producing retinal axial alignment in all control eyes.
Measurement of Membrane Protein Lateral Diffusion in Single Cells
Authors: Edidin M. , Zagyansky Y. , Lardner T. J.
Published: October 2006

Fluorescence rapidly returns to spots bleached by a laser beam in the continuous fluorescence of cultured cells labeled on the surface with fluorescein isothiocyanate. The rate of recovery of fluorescence after bleaching can be interpreted as a measure of the lateral diffusion of integral membrane proteins labeled with fluorescein.
Penalty of Isolationism
Authors: Waksman Selman A.
Published: October 2006

Research on new antibiotics is engaged in at present throughout the world with such intensity that one must be able to compare cultures of organisms producing such antibiotics, as well as the isolated substances themselves, if one is to avoid needless duplication and great confusion. As long as no international center exists where such comparisons can be made, only close collaboration among scientific laboratories can make possible these essential comparisons. The repetitions and the frequently unjustified creation of "new species" of antibiotic-producing organisms and of "new antibiotics" can be avoided only by close collaboration among the scientific workers throughout the world. The creation of an International Antibiotics Board is also highly essential at the present time.
Leukemia and Ionizing Radiation
Authors: Lewis E. B.
Published: October 2006

Leukemia in man can be induced by ionizing radiations and also occurs spontaneously. For the "average" individual in a population, the probability of developing radiation-induced leukemia is estimated to be 2 × 10
–6
per rad (unit of absorbed dose of radiation) per year. The available data from four independent sources make it likely that this estimate is valid within a factor of about 3, giving a range from 0.7 × 10
–6
to 6 × 10
–6
per rad per year. It is pointed out that 10 to 20 percent of the spontaneous incidence of leukemia (Brooklyn, 1943-52) may result from radiation from natural background sources. It is estimated that a 5- to 10-percent increase in the current spontaneous incidence of leukemia would occur if the population were to reach and maintain a body level of Sr
90
amounting to one-tenth of the "maximum permissible concentration."
Carotid Body in the Sudden Infant Death Syndrome
Authors: Naeye Richard L. , Fisher Russell , Ryser Monique , Whalen Philip
Published: October 2006

Sixty-three percent of victims of the sudden infant death syndrome had a subnormal volume and 23 percent an enlarged volume of glomic cells in their carotid bodies. Evidences of antecedent chronic alveolar hypoxia and hypoxemia were found in both groups but were more severe in the victims with enlarged glomic tissue.
Insect Pheromones: Diet Related?
Authors: Hendry L. B.
Published: October 2006

The question of the origin of insect pheromones is discussed in the light of new published information on the communication system of the oak leaf roller. It is concluded that compounds found in diets may be partially responsible for insect sexual behavior and that substructuring of insect populations in ecological and evolutionary time through dietary chemicals remains a hypothesis worthy of further testing.
Falcon Visual Acuity
Authors: Fox Robert , Lehmkuhle Stephen W. , Westendorf David H.
Published: October 2006

Grating acuity, the ability to resolve high-contrast square-wave gratings, was measured in a falcon and in humans under comparable conditions. This behavioral test of falcon acuity supports the common belief that Falconiformes have superb vision—the falcon's threshold was 160 cycles per degree, while the human thresholds were 60 cycles per degree. Falcon acuity, however, was much more dependent on luminance, declining sharply with decreases in luminance.
The "Pincushion Grid" Illusion
Authors: Schachar Ronald A.
Published: October 2006

The illusion generated by a "pincushion grid" is not predicted from the two-dimensional Fourier transform of the grid. This implies that the visual system may not perform two-dimensional Fourier transforms of observed patterns.
Undergraduate Origins of American Scientists
Authors: Holland John L.
Published: October 2006

An analysis of the college attendance or college choice for four high-aptitude, high-school senior samples suggests that the differential institutional productivity of scientists and scholars is a function of the differential college attendance, paternal vocational motivations, and their implied correlates among high-aptitude students. This formulation appears to be more probable for males than for females. The institutional productivity hypothesis proposed in previous studies is not supported by the present evidence.
Structure of a Fibronectin Type III Domain from Tenascin Phased by MAD Analysis of the Selenomethionyl Protein
Authors: Leahy Daniel J. , Hendrickson Wayne A. , Aukhil lkramuddin , Erickson Harold P.
Published: October 2006

Fibronectin type III domains are found in many different proteins including cell surface receptors and cell adhesion molecules. The crystal structure of one such domain from the extracellular matrix protein tenascin was determined. The structure was solved by multiwavelength anomalous diffraction (MAD) phasing of the selenomethionyl protein and has been refined to 1.8 angstrom resolution. The folding topology of this domain is identical to that of the extracellular domains of the human growth hormone receptor, the second domain of CD4, and PapD. Although distinct, this topology is similar to that of immunoglobulin constant domains. An Arg-Gly-Asp (RGD) sequence that can function for cell adhesion is found in a tight turn on an exposed loop.
Intrinsic Quantal Variability Due to Stochastic Properties of Receptor-Transmitter Interactions
Authors: Faber Donald S. , Young William S. , Legendre Pascal , Korn Henri
Published: October 2006

Synaptic events at the neuromuscular junction are integer multiples of a quantum, the postsynaptic response to transmitter released from one presynaptic vesicle. At central synapses where quanta are small, it has been suggested they are invariant due to occupation of all postsynaptic receptors, a concept neglecting inherent fluctuations in channel behavior. If this did occur, the quantal release model would not apply there and could not be used to localize sites of synaptic modification. Monte Carlo simulations of quanta include transmitter diffusion and interactions with postsynaptic receptors that are treated probabilistically. These models suggest that when there are few postsynaptic channels available at a synapse, their stochastic behavior produces significant intrinsic variance in response amplitude and kinetics, and saturation does not occur. These results were confirmed by analysis of inhibitory quanta in embryonic and adult Mauthner cells involving a small and large number of channels, respectively. The findings apply to excitatory synapses as well.
O-methylation, the Principal Route of Metabolism of Epinephrine in Man
Authors: LaBrosse Elwood H. , Axelrod Julius , Kety Seymour S.
Published: October 2006

Evidence is presented which indicates that the principal pathway of metabolism of epinephrine in man is O-methylation to metanephrine. The extent of the conversion to metanephrine, a physiologically inactive compound, indicates that the enzyme responsible for this reaction, catechol-O-methyl transferase, is the enzyme mainly involved in the termination of action of epinephrine in man.
On Nucleon-Antinucleon Symmetry in Cosmology
Authors: Alpher Ralph A. , Herman Robert
Published: October 2006

It has been suggested that cosmological models should embody an initial nucleon-antinucleon symmetry and that the present ratio of nucleons to antinucleons is the result of a statistical fluctuation. Simple arguments are presented for evolutionary models which appear to rule out this possibility in the development of the universe.
Tranquilizing and Antiserotonin Activity of Nicotinamide
Authors: Woolley D. W.
Published: October 2006

Nicotinamide in large amounts antagonized the action of serotonin on smooth muscles in vitro and in vivo. It also tranquilized animals. The antagonism differed in some respects from that of an antimetabolite of serotonin.
Effect of Oxidation and Reduction upon the Biological Activity of Parathyroid Hormone
Authors: Rasmussen Howard
Published: October 2006

Parathyroid hormone loses biological activity upon oxidation with hydrogen peroxide. Part or all of this lost activity can be regained by subsequent reduction with cysteine. The extent and reversibility of this oxidation is dependent upon
p
H.
Functional Transcription Elongation Complexes from Synthetic RNA-DNA Bubble Duplexes
Authors: Daube Shirley S. , von Hippel Peter H.
Published: October 2006

A synthetic RNA-DNA bubble duplex construct intended to mimic the nucleic acid framework of a functional transcription elongation complex was designed and assembled. The construct consisted of a double-stranded DNA duplex of variable length (the template and nontemplate strands) containing an internal noncomplementary DNA "bubble" sequence. The 3′ end of an RNA oligonucleotide that is partially complementary to the template DNA strand was hybridized within the DNA bubble to form an RNA-DNA duplex with a non-complementary 5′-terminal RNA tail. The addition of either
Escherichia coli
or T7 RNA polymerase to this construct formed a complex that synthesized RNA with good efficiency from the hybridized RNA primer in a template-directed and processive manner, and displayed other features of a normal promoter-initiated transcription elongation complex. Other such constructs can be designed to examine many of the functional and regulatory properties of transcription systems.
Activation of Transcription by IFN-γ: Tyrosine Phosphorylation of a 91-kD DNA Binding Protein
Authors: Shuai Ke , Schindler Chris , Prezioso Vincent R. , Darnell James E.
Published: October 2006

Interferon-γ (IFN-γ) induces the transcription of the gene encoding a guanylate binding protein by activating a latent cytoplasmic factor, GAF (gamma-activated factor). GAF is translocated to the nucleus and binds a DNA element, the gamma-activated site. Through cross-linking and the use of specific antibodies GAF was found to be a 91-kilodalton DNA binding protein that was previously identified as one of four proteins in interferon-stimulated gene factor-3 (ISGF-3), a transcription complex activated by IFN-α. The IFN-γ-dependent activation of the 91-kilodalton DNA binding protein required cytoplasmic phosphorylation of the protein on tyrosine. The 113-kilodalton ISGF-3 protein that is phosphorylated in response to IFN-α was not phosphorylated nor translocated to the nucleus in response to IFN-γ. Thus the two different ligands result in tyrosine phosphorylation of different combinations of latent cytoplasmic transcription factors that then act at different DNA binding sites.
Critical Period for Effects of Infantile Experience on Maturation of Stress Response
Authors: Levine Seymour , Lewis George W.
Published: October 2006

Manipulated infant rats respond to cold with depletion of adrenal ascorbic acid (AAA) significantly earlier than nonmanipulated infants. The study discussed in this report examined the critical period for infantile manipulation on the depletion of AAA. It was found that infant rats manipulated immediately following birth exhibited significant AAA depletion, whereas infants manipulated later did not exhibit depletion.
Direct Observation of Evaporation from Quiescent Water
Authors: Mysels Karol J.
Published: October 2006

The color change of a filter paper impregnated with cobaltous chloride and held just above the surface of water gives a good indication of the rate at which evaporation proceeds from individual regions of the surface. The marked effect of some monolayers on thermal convection currents within the liquid can be thus shown.
Requirements for Growth of Single Human Cells
Authors: Lockart Royce Z. , Eagle Harry
Published: October 2006

A minimal growth medium supplemented with dialyzed serum, which sufficed for the propagation of a wide variety of human cell strains in heavily inoculated monolayer and suspension cultures, did not permit the regular or optimal growth of small numbers of HeLa, HeLa S3, conjunctiva, or KB cells deriving from suspension cultures. At threshold concentrations of serum, the plating efficiency of single cells was greatly reduced as compared with their plating efficiency in a medium containing dialyzed serum instead of whole serum, and the clones which did develop grew at a slower rate. The nutritional deficiency could be overcome by adding the seven amino acids which are ordinarily not nutritionally essential. In most of the experiments serine alone sufficed.
Analysis of Gas in Biological Fluids by Gas Chromatography
Authors: Ramsey Lloyd H.
Published: October 2006

Combining a vacuum extraction method with gas chromatography makes possible accurate, reproducible determination of small quantities of permanent gases contained in biological fluids. One useful application is demonstrated by determining the oxygen tension in 1 ml of human plasma.
Molecular Structural Factors in Competitive Inhibition of Sugar Transport
Authors: LeFevre Paul G.
Published: October 2006

The high potency of phloretin as a competitive inhibitor of the human red cell's monosaccharide transport system is not shared by any of several molecular fragments of phloretin, but is duplicated in certain artificial estrogens resembling phloretin in respect to the spacing between terminal phenolic —OH groups. Related molecules which are slightly less extendible are comparatively inactive.
College Environments and the Development of Talent
Authors: Thistlethwaite Donald L.
Published: October 2006

A method for comparing the effectiveness of undergraduate colleges in stimulating their students to seek the Ph.D. is described. The procedure yields separate measures of productivity in the natural sciences and in the arts, humanities, and social sciences, adjusted to control differences in college talent supplies. The results suggest that the productivity measures have substantial validity, and argue for the importance of faculty behaviors in stimulating or inhibiting intellectual achievement.
Alterations in the Pattern of Amine Excretion in Man Produced by a Monoamine Oxidase Inhibitor
Authors: Sjoerdsma A. , Lovenberg W. , Oates J. A. , Crout J. R. , Udenfriend S.
Published: October 2006

The administration of monoamine oxidase inhibitors produces an increase in the urinary excretion of many amines for which efficient alternate routes of metabolism are not available. These include tryptamine, paratyramine, and a "metatyramine-like" substance. The inhibitors can therefore be used to detect previously unsuspected pathways of amino acid decarboxylation. The finding that the excretions of norepinephrine, epinephrine, 3,4-dihydroxyphenylethylamine, and possible serotonin are not appreciably affected are consistent with previous reports of the existence of alternative metabolic routes.
Control of Oöcyte Development in Cockroaches
Authors: Roth Louis M. , Stay Barbara
Published: October 2006

Development of ovarian eggs and secretory activity of colleterial glands are inhibited by the oötheca in the oöthecal chamber of
Blattella germanica
(L.) and by the oötheca in the uterus of
Pycnoscelus surinamensis
(L.). The inhibition is due to nervous stimuli from pressure of the oötheca. Removing the oötheca or severing the ventral nerve cord eliminates inhibition of the
corpora allata
and results in premature development of the oöcytes and resumption of activity of the colleterial glands.
10-Hydroxy-Δ
2
-Decenoic Acid, an Antibiotic Found in Royal Jelly
Authors: Blum Murray S. , Novak Arthur F. , Taber Stephen
Published: October 2006

10-Hydroxy-Δ
2
-decenoic acid, the major component of the lipide fraction of royal jelly, exhibits antibiotic activity against many bacteria and fungi. This fatty acid is less than one-fourth as active as penicillin against
Micrococcus pyogenes
and less than one-fifth as active as chlortetracycline against
Escherichia coli.
It also slows the growth rate of
Neurospora sitophila
and some unidentified molds. The salt of this compound is considerably less active than the free acid.
Prolactin, a Factor in Promoting Survival of Hypophysectomized Killifish in Fresh Water
Authors: Pickford Grace E. , Phillips John G.
Published: October 2006

The naturally occurring corticosteroids, cortisol and aldosterone, failed to promote survival of hypophysectomized
Fundulus heteroclitus
in fresh water. Extracts of
Fundulus
interrenal tissue, carp corpuscles of Stannius, and hog renin were ineffective. Injection of whole rat-pituitary brei was partially successful. Highly purified prolactin maintained survival, although the recipients did not eat normally. A synergic action of prolactin with some unidentified pituitary hormone is suspected.
Average Potassium Concentration of the Human Body as a Function of Age
Authors: Anderson E. C. , Langham W. H.
Published: October 2006

Potassium-40 measurements on 1590 males and females ranging in age from less than 1 year to 79 years show sex differences and age trends in the ratio of muscle mass to the mass of other body constituents. A sex difference first appears at approximately 12 years of age. While females show a continuous decrease in potassium concentration, males show a rapid increase between the ages of 14 and 16. During adult life both sexes show a persistent and parallel decrease, which may be related to physiologic aging.
Peculiar Feeding of
Amphiuma
under Conditions of Enforced Starvation
Authors: Brode William E. , Gunter Gordon
Published: October 2006

Two
Amphiuma means
confined in aquaria with flowing artesian water for 3 years, with no known supply of food, increased in size. In the latter part of this period they were observed to shed a sheet of skin by a peculiar process and to devour it. This shed skin contained bacteria of the spirilla type, diatoms, and large amounts of unicellular algae, and possibly other organisms. Similar behavior in unstarved specimens of
Cryptobranchus
confined in an aquarium at the University of Alabama has been observed by E. L. Bishop.
Chemically Induced Phenocopy of a Tomato Mutant
Authors: Mathan David S. , Jenkins James A.
Published: October 2006

Lanceolate, a spontaneous leaf-shape mutant which fails to produce cotyledons and plumule in the homozygous condition, shows development if supplied with either adenine or a diffusate obtained from normal seeds. Similar development occurs in a different genetic background.
Effect of Stress on Skin Transplantation Immunity in Mice
Authors: Wistar R. , Hildemann W. H.
Published: October 2006

Chronic avoidance-learning stress was found to depress the immune reaction responsible for skin homograft rejection to a modest but significant degree. This effect was observed in a genetically uniform as well as a heterogeneous line of mice.
Site and Mechanism of Tick Paralysis
Authors: Murnaghan Maurice F.
Published: October 2006

A neurophysiological investigation indicates that the paralysis produced in the dog by the wood tick,
Dermacentor andersoni
Stiles, is due to failure in the liberation of acetylcholine at the neuromuscular junction because of a conduction block in the somatic motor fibers produced by the tick "toxin."
Effect of Acclimation on the Preferred Body Temperature of the Lizard,
Sceloporus occidentalis
Authors: Wilhoft Daniel C. , Anderson James D.
Published: October 2006

The preferred body temperature was determined for several groups of
Sceloporus occidentalis
previously acclimated to several constant temperature levels. Acclimation to a high temperature (35°C) resulted in the selection of a lowered mean preferred body temperature, whereas acclimation to lower temperatures (12°C and 25°C) produced no change in the preferred body temperature.
Function of the Rectal Gland in the Spiny Dogfish
Authors: Burger J. Wendell , Hess Walter N.
Published: October 2006

The rectal gland of the spiny dogfish,
Squalus acanthias
, secretes a fluid which is essentially a sodium chloride solution with a concentration about twice that of the plasma and greater than that of sea water. Observed volumes of flow are sufficiently large to make it clear that the rectal gland can remove from the blood relatively large amounts of sodium chloride, and presumably this is its function.
Adaptation of Cardiac Output to Peripheral Runoff Studied in Intact Dogs
Authors: Pieper Heinz P.
Published: October 2006

A pump with sinusoidal piston movement was connected to the abdominal aorta of intact anesthetized dogs, causing slow oscillations of arterial blood pressure. Evidence was found for the existence of a mechanism which enables the heart to adjust its output immediately to changes of peripheral outflow.
Isolation of a Bacteriophage Specific for the F+ and Hfr Mating Types of
Escherichia coli
K-12
Authors: Loeb Tim
Published: October 2006

Seven phage stocks have been prepared from a sample of sewerage. The stocks grow only on the F+ and Hfr mating types of
Escherichia coli
strain K-12. This specificity is not shared by any previously characterized phage which was tested. The specificity of one of the isolates, f1, has been well correlated with the salmonella cross-streak test described by Zinder.
Amber with Insect and Plant Inclusions from the Dominican Republic
Authors: Sanderson Milton W. , Farr Thomas H.
Published: October 2006

An amber-bearing formation observed in the Dominican Republic in 1959 is described, and several insect orders, spiders, and plants found in amber are noted. An amber trace is recorded for Haiti, and the known fossil-bearing amber deposits or sites in the New World are summarized.
Physiological Measurements on a Live Whale
Authors: Kanwisher John , Senft Alfred
Published: October 2006

Temperature, respiration, and electrocardiographic measurements were made on a stranded 45-ft. finback whale. This proved to be a practical means of getting physiological information on the large cetaceans.
Late Glacial and Postglacial Hudson Bay Sea Episode
Authors: Lee Hulbert A.
Published: October 2006

Geological investigations, archeological studies, and radiocarbon dates indicate a similarity of events around Hudson Bay, commencing at the time Hudson Bay Basin was freed of glacier ice. The sea that then spread around Hudson Bay 7000 to 8000 years ago is here named "Tyrrell Sea." The subsequent rate of land emergence decreased exponentially.
Search for Artificial Stellar Sources of Infrared Radiation
Authors: Dyson Freeman J.
Published: October 2006

If extraterrestrial intelligent beings exist and have reached a high level of technical development, one by-product of their energy metabolism is likely to be the large-scale conversion of starlight into far-infrared radiation. It is proposed that a search for sources of infrared radiation should accompany the recently initiated search for interstellar radio communications.
Weber Ratio for Visual Discrimination of Velocity
Authors: Brown Robert H.
Published: October 2006

As an approximation based on various experiments reported in the literature, the least detectable difference in speed (Δ ω) varies in direct proportion to the speed (ω) over a range from 0.1 to 20 degrees of visual angle per second. The constancy of the Weber ratio (Δω/ω) aids in understanding how men react to velocity in various situations.
Tertiary Structure Around the Guanosine-Binding Site of the
Tetrahymena
Ribozyme
Authors: Wang Jin-Feng , Cech Thomas R.
Published: October 2006

A cleavage reagent directed to the active site of the
Tetrahymena
catalytic RNA was synthesized by derivatization of the guanosine substrate with a metal chelator. When complexed with iron(II), this reagent cleaved the RNA in five regions. Cleavage at adenosine 207, which is far from the guanosine-binding site in the primary and secondary structure, provides a constraint for the higher order folding of the RNA. This cleavage site constitutes physical evidence for a key feature of the Michel-Westhof model. Targeting a reactive entity to a specific site should be generally useful for determining proximity within folded RNA molecules or ribonucleoprotein complexes.
Calcium-Permeable AMPA-Kainate Receptors in Fusiform Cerebellar Glial Cells
Authors: Burnashev N. , Khodorova A. , Jonas P. , Helm P. J. , Wisden W. , Monyer H. , Seeburg P. H. , Sakmann B.
Published: October 2006

Glutamate-operated ion channels (GluR channels) of the L-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-kainate subtype are found in both neurons and glial cells of the central nervous system. These channels are assembled from the GluR-A, -B, -C, and -D subunits; channels containing a GluR-B subunit show an outwardly rectifying current-voltage relation and low calcium permeability, whereas channels lacking the GluR-B subunit are characterized by a doubly rectifying current-voltage relation and high calcium permeability. Most cell types in the central nervous system coexpress several subunits, including GluR-B. However, Bergmann glia in rat cerebellum do not express GluR-B subunit genes. In a subset of cultured cerebellar glial cells, likely derived from Bergmann glial cells. GluR channels exhibit doubly rectifying current-voltage relations and high calcium permeability, whereas GluR channels of cerebellar neurons have low calcium permeability. Thus, differential expression of the GluR-B subunit gene in neurons and glia is one mechanism by which functional properties of native GluR channels are regulated.
Tropomyosin Binding to F-Actin Induced by Myosin Heads
Authors: Eaton Barbra L.
Published: October 2006

Tropomyosin is a regulatory protein associated with F-actin in many actomyosin contractile systems. If in vitro conditions are such that tropomyosin binds only slightly to F-actin, then the addition of myosin heads can induce stoichiometric binding between them. This suggests that formation of rigor bonds between actin and myosin heads may cause some change in the actin, stabilizing the appropriate binding site for tropomyosin.
Dialysis of Certain Sugars through Cellophane
Authors: Templeman Malcolm B. , Marshall Lawrence M.
Published: October 2006

Of several sugars examined, alkali most affects the rate of dialysis through cellophane of alpha-beta-D-mannose and alpha-beta-maltose. The rates of dialysis of these two sugars are influenced by 0.01 and 0.1
N
solutions of sodium and potassium hydroxide. The rate of dialysis of sucrose is not influenced by the solutions employed.
Regulation of Reproductive Rate by Intra-uterine Mortality in the Deer Mouse
Authors: Helmreich R. L.
Published: October 2006

Under crowded conditions (four mating pairs per cage), pregnant female deer mice of a partially domesticated strain,
Peromyscus maniculatus bairdii
, showed increased resorption of implanted embryos, and therefore a 60 percent reduction in effective natality, as compared with control females living at a population density of one pair per cage. No significant difference was found in the incidence of pregnancy or in the number of embryos implanted, but the adrenal glands of crowded females were enlarged by an average of 17 percent (by weight).
Avoidance Learning and Relearning as a Function of Shuttlebox Dimensions
Authors: Denny M. Ray , Thomas Jay O.
Published: October 2006

Rats in a low-ceiling shuttlebox initially show a lower level of learning than rats in a high-ceiling box. After an hour's interruption of conditioning the performance of animals in low-ceiling boxes improves and avoidance is slightly more efficient than in the unimproved performance of animals in high-ceiling boxes. Box height also interacts significantly with length of box.
Observing Behavior in a Vigilance Task
Authors: Baker C. H.
Published: October 2006

It has been suggested that level of performance in a vigilance task is accurately reflected by frequency of observing responses. By means of photography it has been demonstrated that under conditions where a decrement in vigilance performance does not occur, the frequency of nonobserving behavior and general activity increases in time.
Completion of Meiosis in Uninseminated Eggs of
Drosophila melanogaster
Authors: Doane W. W.
Published: October 2006

Contrary to earlier statements, meiosis goes to completion in "unfertilized" eggs of
Drosophila melanogaster
. Evidence suggests that this is not only characteristic of the strain examined but of the species as a whole and of other Drosophila species as well.
Relationship between Feeding and Satiation Centers of the Hypothalamus
Authors: Wyrwicka W. , Dobrzecka C.
Published: October 2006

Electrodes were implanted in the hypothalamus of five goats in which an alimentary instrumental conditioned reflex had been previously established. Electrical stimulation of the ventromedial hypothalamus inhibited the conditioned movements and food intake in hungry goats. This also occurred in those satiated goats in which eating and conditioned movements were elicited by stimulation of the lateral hypothalamic area. Withdrawal of the stimulation of the medial hypothalamus evoked a short aftereffect in the form of a recovery or increase in the trained movements and food intake.
Temperate Pollen Genera in the Eocene (Claiborne) Flora, Alabama
Authors: Gray Jane
Published: October 2006

Pollen, spores, hystrichospherids, dinoflagellates, and the fresh-water alga
Pediastrum
occur in marine clays at the classic Claiborne Bluffs locality, Alabama. The presence of
Ephedra
pollen provides the first documented Tertiary record of this genus from the southeastern states. The occurrence of several characteristically temperate genera lends support to the idea that a deciduous hardwood forest was present in the Appalachian uplands during the Eocene.
Effect of Galactose-1-Phosphate on Glucose Oxidation by Normal and Galactosemic Leukocytes
Authors: Weinberg Arnold N. , Segal Stanton
Published: October 2006

During incubation with galactose, galactosemic leukocytes accumulated more galactose-1-phosphate than did normal leukocytes. Concomitant determination of glucose oxidation, with C
14
glucose, revealed no inhibition of the hexosemonophosphate pathway. These results are at variance with recent studies in rat lens tissue, which suggests that intracellular galactose-1-phosphate depressed glucose-6-phosphate dehydrogenase activity and the oxidative pathway.
Effect of Reserpine on Ventricular Escape
Authors: Roberts Jay , Stadter Richard P.
Published: October 2006

Catecholamine depletion by reserpine diminishes the tendency of the ventricle to escape from vagal suppression. Neither spinal section nor adrenalectomy enhances the reserpine effect. Norepinephrine restores the characteristic occurrence of ventricle escape during vagal stimulation.
Mechanism of Fibrillation Potentials in Denervated Mammalian Skeletal Muscle
Authors: Li Choh-Luh
Published: October 2006

This report concerns the origin and mechanism of fibrillation potentials. It is proposed that these potentials do not necessarily arise from degenerated endplate organs. The precursor is the rhythmic oscillations of the membrane potential. This mechanism may also occur in the case of epileptic discharges from epileptic cells in the cerebral cortex.
Isolation of Eastern Equine Encephalitis Virus from
Aedes albopictus
in Florida
Authors: Mitchell C. J. , Niebylski M. L. , Smith G. C. , Karabatsos N. , Martin D. , Mutebi J. P. , Craig G. B. , Mahler M. J.
Published: October 2006

Fourteen strains of eastern equine encephalitis (EEE) virus were isolated from
Aedes albopictus
mosquitoes collected in Polk County, Florida. These are the first isolations of an arbovirus of proven public health and veterinary importance from naturally infected
Ae. albopictus
in the United States since established populations of this introduced mosquito were first discovered in 1985. The widespread distribution of
Ae. albopictus
in Florida and in other areas of the United States where EEE is endemic raises concern that this species may become an epizootic and epidemic vector of EEE virus.
Role of Transmembrane Domain Interactions in the Assembly of Class II MHC Molecules
Authors: Cosson Pierre , Bonifacino Juan S.
Published: October 2006

Evidence is presented that suggests a role for transmembrane domain interactions in the assembly of class II major histocompatibility complex (MHC) molecules. Mutations in the transmembrane domains of the class II MHC α or β chains resulted in proteins that did not generate complexes recognized by conformation-dependent antibodies and that were largely retained in the endoplasmic reticulum. Insertion of the α and β transmembrane domains into other proteins allowed the chimeric proteins to assemble, suggesting a direct interaction of the α and β transmembrane domains. The interactions were mediated by a structural motif involving several glycine residues on the same face of a putative α helix.
Early Pleistocene Paleoclimatic Record from Sonoran Desert, Arizona
Authors: Gray Jane
Published: October 2006

Three pollen spectra from lake sediments stratigraphically well below mid-Kansan fauna indicate plant associations for the Sonoran desert, Arizona, approximating those found now at elevations of 1500 ft and more above the desert floor. The presence of
Ostrya
,
Betula
, and
Artemisia
may indicate some invasion by northern species as well. A climate cooler or wetter, or both cooler and wetter, than the present climate is inferred from paleobotanical and sedimentary evidence. Correlation with the Nebraskan glacial stage is tentatively suggested.
Excessive Stimulation of Salivary Gland Growth by Isoproterenol
Authors: Selye Hans , Veilleux Rene , Cantin Marc
Published: October 2006

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.
Evoked Cortical Potentials in Absence of Middle Ear Muscles
Authors: Moushegian George , Rupert Allen , Marsh James T. , Galambos Robert
Published: October 2006

Evoked potentials to click at auditory cortex were recorded from cats deprived of middle ear muscles. Variations in the amplitude of the response after surgery indicate that the participation of these muscles in habituation, conditioning, and distraction must be minimal.
A Mechanism of Light Adaptation
Authors: Lipetz Leo E.
Published: October 2006

In the isolated retina of the bullfrog (
Rana catesbiana
) illumination of one part of a ganglion cell's receptive field increased the light threshold (for response by that cell) not only in the illuminated part but also in the unilluminated parts of the field. Scattered light is insufficient to account for the effect. Apparently it depends on changes in the efficiency of excitation transmission along the neural pathways from photoreceptors to ganglion cell.
Alterations in Sialic Acid Content of Human Transferrin
Authors: Parker W. Carey , Bearn Alexander G.
Published: October 2006

Starch gel electrophoresis of human transferrin treated with neuraminidase revealed a pattern of five bands whose intensities varied with neuraminidase concentration. Sialic acid analysis after starch block electrophoresis suggested that the bands represented the stepwise removal of sialic acid from the transferrin molecule. Evidence was also obtained for the purification of a particular genetic transferrin variant.
Uptake of Tritium-Labeled Norepinephrine in Brain and Other Tissues of Cat in vitro
Authors: Dengler Hans J. , Spiegel Herbert E. , Titus Elwood O.
Published: October 2006

Slices of cat cerebral cortex, heart, and spleen that have been incubated in media containing approximately 5 to 25 mμg of
dl
-norepinephrine-7H
3
per milliliter contain levels of isotopic amine greater than those in the medium. The effects of norepinephrine concentration, reserpine, and ouabain on the uptake suggest that the amine enters cells both by diffusion and by a concentrating mechanism that is saturated at low levels of norepinephrine. The drugs inhibit the latter.
Recovery from Electroconvulsive Shock as a Function of Infantile Stimulation
Authors: Bell Robert W. , Reisner Gerald , Linn Theodore
Published: October 2006

Eighty Wistar rats were handled at 2 to 5, 6 to 9, or 10 to 13 days of age, or not at all. In adulthood each group was split into halves with one-half of each group receiving electroconvulsive shock treatment. Assays of sugar concentration in the blood serum 24 hours after the convulsions indicated that subjects handled at 2 to 5 days of life exhibited no effect of the treatment, whereas all other groups showed marked increases in blood sugar concentration.
Isotopic Variations in Meteoric Waters
Authors: Craig Harmon
Published: October 2006

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.
Germination of Bacterial Endospores with Calcium and Dipicolinic Acid
Authors: Riemann Hans , Ordal Z. John
Published: October 2006

Aerobic and anaerobic bacterial endospores can be germinated if calcium chloride and dipicolinic acid are added to well-washed suspensions. Maximum germination is obtained when the calcium and acid are present in a molar ratio of one or more. This suggests that the 1:1 chelate of calcium and dipicolinic acid is the agent that induces germination.
Response Latencies of Female Rats during Sexual Intercourse
Authors: Bermant Gordon
Published: October 2006

A female rat, by operating a lever, causes the presentation of a potent male rat and subsequent sexual contact. The female shows contact-response latencies that vary according to the nature of the contact. Latencies after ejaculations are longer than those after intromissions, which in turn exceed those after mounts.
Role for Ganglionic Norepinephrine in Sympathetic Synaptic Transmission
Authors: Costa E. , Revzin A. M. , Kuntzman R. , Spector S. , Brodie B. B.
Published: October 2006

Transmission of nerve impulses in superior cervical sympathetic ganglia of cats and rabbits is markedly enhanced after reserpine-induced depletion of ganglionic norepinephrine. Transmission is also enhanced by administration of adrenergic blocking agents. In contrast, reserpine-induced release of ganglionic norepinephrine in animals pretreated with a monoamine oxidase inhibitor results in a pronounced depression of ganglionic transmission, which lasts until the ganglionic norepinephrine disappears. These results support the concept that norepinephrine in ganglia modulates the action of acetylcholine.
Auxetic Growth in the Javanese Toad,
Bufo melanostictus
Authors: Church Gilbert
Published: October 2006

Morphologically, it has been found that erythrocyte size in the Javanese toad is greater in large than in small animals, and preliminary data indicate that the same is true of kidney, intestinal, and liver cells. Physiologically, the hemoglobin concentration, packed cell volume, specific gravity of the whole blood, and the liver glycogen concentration also increase with the size of the animals.
Osteogenic Induction across Millipore Filters in vivo
Authors: Goldhaber Paul
Published: October 2006

Immunization of host mice to homograft tissues prior to subcutaneous implantation of homograft bone' within diffusion chambers did not prevent new bone formation on the host side of the filter, thereby indicating its origin from host cells in response to a diffusible osteogenic inductor from within the chamber rather than from undetected escaping homograft cells.
Correlation between Mean Litter Size and Mean Life Span among 12 Inbred Strains of Mice
Authors: Roderick Thomas H. , Storer John B.
Published: October 2006

In 12 inbred strains of mice there was no general correlation between litter size and parental life span within strains, although a significant between-strain correlation of +0.69 was found between mean life span of the dams and the mean size of their litters. When data for AKR/J mice, which characteristically die early from leukemia, were excluded, the correlation was increased to +0.90 for the remaining 11 strains. These findings indicate that the correlation is of genetic origin—that is, that genes affecting a dam's life span also affect the size of her litters.
Blood Trehalose and Flight Metabolism in the Blowfly
Authors: Clegg James S. , Evans David R.
Published: October 2006

The concentration of trehalose in the blood of
Phormia regina
was found to determine the rate of energy expenditure during flight as reflected in measurements of the wing-beat frequency. Fat body was found to be the source of blood trehalose; either endogenous or exogenous substrates are used for its synthesis.
Variations in Thermal Sensitivity
Authors: Kenshalo D. R. , Nafe John P. , Brooks Barbara
Published: October 2006

In the past, confusion has resulted from the use of relative expressions indicative of the direction of temperature change, rather than positive identification of warm and cool sensations. Data are presented which show that at more extreme skin temperatures sudden changes in temperature may result in two readily discernible sensations. The occurrence of each sensation depends upon the magnitude of the change.
Haptoglobin and Transferrin Gene Frequencies in a Navajo Population: A New Transferrin Variant
Authors: Parker W. Carey , Bearn Alexander G.
Published: October 2006

The distribution of serum haptoglobin, transferrin, and ceruloplasmin has been studied by starch gel electrophoresis for a Navajo Indian population in Arizona. Only the three common haptoglobin phenotypes were observed, but a high percentage of a new faster-moving transferrin variant
B
0-1
was discovered. No unusual ceruloplasmins were found.
Anopheles hackeri
, a Vector of
Plasmodium knowlesi
in Malaya
Authors: Wharton R. H. , Eyles Don E.
Published: October 2006

Anopheles hackeri
, a mosquito commonly found breeding in nipa palm leaf bases along the Malayan coast, was demonstrated to be infected with
Plasmodium knowlesi
by the inoculation of sporozoites into an uninfected rhesus monkey. This was the first demonstration of a natural vector of any monkey malaria.
Succession in Desert Vegetation on Streets of a Nevada Ghost Town
Authors: Wells Philip V.
Published: October 2006

Vegetation was sampled on the old street system of Wahmonie, Nevada, and on a less disturbed area immediately adjacent. The vegetation on the denuded upland site showed a large increase in bunch-grass and an invasion by pioneer shrubs which ordinarily are chiefly confined to dry washes.
General Method of Plotting Kinetic Data for Reactions of Any Order
Authors: Pessen Helmut
Published: October 2006

A method is presented for obtaining from kinetic experiments both order of reaction and rate constant by means of a single straight-line graph, in contrast to previous methods, which require several steps including more than one graph or repeated trial-and-error calculations whenever there is no prior knowledge of the order of reaction.
Progressive Ratio as a Measure of Reward Strength
Authors: Hodos William
Published: October 2006

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.
Phagocytized Platelets: A Source of Lipids in Human Thrombi and Atherosclerotic Plaques
Authors: Chandler A. B. , Hand R. A.
Published: October 2006

Phagocytosis of lipid-rich platelets by monocytes and the transformation of such cells into lipophages containing fat was observed in human thrombi. The lipophages are similar to lipophages in atherosclerotic plaques. This observation supports the idea that some atherosclerotic plaques are organized mural thrombi.
Relationship of Blood Type to Histocompatibility in Chickens
Authors: Schierman Louis W. , Nordskog Arne W.
Published: October 2006

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.
Reactivity Cycle of Somatosensory Cortex in Humans with and without Psychiatric Disorder
Authors: Shagass Charles , Schwartz Marvin
Published: October 2006

With a photographic averager to extract evoked cortical responses, reactivity cycles of primary potentials were determined over 200 milliseconds in 105 subjects. The typical cycle was biphasic, with peaks before 20 and after 100 msec. Subjects who were not psychiatric patients showed full recovery of responsiveness during the initial peak phase, whereas most of the psychiatric patients did not.