bluuebunny/crossref_metadata_2025 huggingface dataset:
Libration of Pluto-Neptune
Authors: Cohen C. J. , Hubbard E. C.
Published: October 2006

Numerical integration of the orbits of the five outer planets over 120,000 years reveals that the distance between Pluto and Neptune at the closest approaches oscillates within a narrow range. The distance is never much less than the aphelion distance of Pluto from the orbit of Neptune. The near commensurability in the periods of Pluto and Neptune and the eccentricity of Pluto's orbit are responsible for the libratory motion.
Phenethyl Alcohol Synergism with Mitomycin C, Porfiromycin, and Streptonigrin
Authors: White James R. , White Helen L.
Published: October 2006

Cyanide and phenethyl alcohol greatly enhance the lethal action of mitomycin C, porfiromycin, and streptonigrin on an exponentially growing culture of
Escherichia coli
. Dinitrophenol similarly enhances the lethal action of mitomycin C and porfiromycin, but only slightly that of streptonigrin. Phenethyl alcohol may be functioning in these experiments as an inhibitor of electron transport.
Antigenic Behavior of Moloney Lymphomas: Independence of Virus Release and Immunosensitivity
Authors: Klein George , Klein Eva
Published: October 2006

Mouse lymphomas induced by Moloney virus were compared with regard to their ability to elicit humoral antibodies against Moloney cells, to sensitize against Moloney isografts, and to respond to established isograft resistance. The first two properties were parallel, while the third was independent. The former, but not the latter, is attributed to the release of infectious virus.
Skin Tumorigenesis by 7,12-Dimethylbenz(
a
)anthracene: Inhibition by Actinomycin D
Authors: Gelboin Harry V. , Klein Michael
Published: October 2006

Topical application of actinomycin D during a short period of time immediately before and after a single application of 7, 12- dimethylbenz (
a
)anthracene markedly inhibits subsequent tumor formation. The results indicate that the initial events of carcinogenesis are dependent on DNA-dependent RNA synthesis.
Explorations with the Hale Telescope
Authors: Bowen I. S.
Published: October 2006

The 200-inch telescope has performed much as Hale had hoped and predicted. Most of the programs he listed have made large advances. A very few have run into unforeseen difficulties. On the other hand, important breakthroughs have occurred along lines of which Hale had no inkling. If Hale were with us today I believe he would be content with the results of the great adventure he started.
Culture of Embryonic Cells of
Drosophila melanogaster
in vitro
Authors: Horikawa Masakatsu , Fox Allen S.
Published: October 2006

Embryonic cells isolated from eggs of
Drosophila melanogaster
have been cultured continuously in a new medium. Generation time for cell division is 30 hours. Chromosome number remains constant for at least 10 days. Cells from embryos of the mutant maroon-like grow at the same rate as those from wild-type embryos, but cells from rosy-2 grow slower and at a lower optimum temperature.
Strontium and Calcium Uptake by the Green Alga,
Oocystis eremosphaeria
Authors: Kevern Niles R.
Published: October 2006

The uptake of calcium and strontium by a green unicellular alga cultured in media containing these elements in concentrations found in nature is directly proportional to the concentration in the media. Variation in the concentration of either element has a slight inverse influence on the uptake of the other. The increase of strontium uptake when the calcium concentration is very low indicates that strontium is substituted for calcium when calcium is limited and suggests that the alga requires either element.
Sulfate Transport in Human Red Cells: Inhibition by Some Uncouplers of Oxidative Phosphorylation
Authors: Omachi Akira
Published: October 2006

Release of inorganic sulfate from human erythrocytes is depressed in the presence of 2,4-dinitrophenol (5 × 10
-4
M
) or dicumarol (5 × 10
-4
M
). This effect cannot be readily attributed to uncoupling of phosphorylation from respiration, since the study was conducted with cells that metabolize principally by anaerobic means and since the effect was not influenced by iodoacetic acid. A more reasonable explanation may be that permeability of the erythrocyte membrane to anions may be reduced by these agents.
Gravitational Stress: Changes in Cortical Excitability
Authors: Nicholson Anthony N.
Published: October 2006

Evoked responses, recorded from the visual cortex, are enhanced during positive (head to tail) acceleration, and during cerebral hypotension induced by hemorrhage. The phenomenon observed during positive acceleration may therefore be due, at least in part, to its hypotensive effect, but the increased somatic stimulation must also be considered.
Chromosome Abnormalities in vitro in Human Leukocytes Associated with Schmidt-Ruppin Rous Sarcoma Virus
Authors: Nichols W. W. , Levan A. , Coriell L. L. , Goldner H. , Ahlström C. G.
Published: October 2006

Chromosome breakage was observed in human leukocytes in vitro when Schmidt-Ruppin strain of Rous sarcoma virus was added to the cultures. Similar additions of Bryan strain of Rous sarcoma virus had no such effect.
Radiation-Chemical Oxidation of Peptides in the Solid State
Authors: Garrison Warren M. , Jayko Michael E. , Bennett-Corniea Winifred
Published: October 2006

Gamma-ray irradiation of polypeptides as highly dispersed fluffs under oxygen leads to chemical degradation of the peptide bond with the remarkably high oxygen consumption of about one molecule per 2 ev of absorbed energy. A radical chain mechanism appears to be involved, and there is evidence that excited states of the polypeptide aggregate undergo chemical quenching by molecular oxygen.
Chromosome Aberrations: Their Role in the Etiology of Murine Leukemia
Authors: Rich Marvin A. , Tsuchida Ryoichi , Siegler Richard
Published: October 2006

If the association between chromosome aberrations and leukemia is a causal one, the aberrations should be present before the appearance of tumor. In a virus-induced murine leukemia in which the pre- and early leukemic stages were defined, aneuploidy was observed only during the later stages of the disease. This suggests that the chromosome alteration results from, rather than initiates, the neoplastic transformation.
Oscillations of Quasars
Authors: McVittie G. C.
Published: October 2006

Rotation in addition to free gravitational motion can produce oscillations in a large spherical mass of gas. The theory may provide an explanation of the variations of brightness in such objects as 3C273.
High-Voltage Laue X-ray Photography of Large Single Crystals
Authors: Paretzkin B. , Peiser H. Steffen
Published: October 2006

The perfection of relatively large single crystals can be tested by Laue transmission x-ray diffraction photographs by using much higher voltages for the x-ray generation than are used in conventional diffraction experiments. The technique can be used for determining the orientation spread of subcrystal units and for studying the loss of primary extinction due to occluded chemical impurities. An advantage of this method is its possible application to crystals inside polycrystalline or glass containers.
Johnson or Goldwater—Two Scientists Explain Their Choice
Authors: Kistiakowsky G. B. , Teller Edward
Published: October 2006

Since scientists seem to be showing an unusually active interest in the current presidential election campaign,
Science
has asked two politically active leaders of the scientific community to state the reasons for their political choice. Specifically, they were asked to explain their political preference, "with particular emphasis on matters of direct professional interest to the scientific community, such as federal support for education and basic research . . . (and) . . . how the outcome of the election might affect the present relationship between science and government, including the effects it might have on the development and quality of American science."
Valence and Affinity of Equine Nonprecipitating Antibody to a Haptenic Group
Authors: Klinman N. R. , Rockey J. H. , Karush F.
Published: October 2006

A nonprecipitable antibody to a haptenic group has been purified from equine serum. It is a 7
S
β
2A
immunoglobulin with high affinity for the specific hapten and two binding sites per antibody molecule. These results rule out univalence and low affinity as explanations of the nonprecipitability of this antibody.
Self-Presentation and Self-Termination of a Conflict-Producing Stimulus
Authors: Hearst Eliot , Koresko Minnie B.
Published: October 2006

Rats could press a lever to initiate or terminate a stimulus that was associated with intermittent rewards and punishments. Subjects spent time in both the stimulus-on and stimulus-off condition and oscillated frequently between the two conditions. This method provides continuous, quantitative records of oscillatory behavior and is sensitive to manipulations of shock intensity and food deprivation as well as the relative frequency of reward and punishment.
Spore Discharge Mechanism in Basidiomycetes
Authors: Olive Lindsay S.
Published: October 2006

Spore discharge in basidiomycetes is effected primarily by the explosion of a small gas bubble in the area of the apiculus of the spore and by pressure of residual gas (probably carbon dioxide) that has accumulated between the inner wall and outer membrane of the spore apparatus. A somewhat similar mechanism of discharge has been discovered in an undescribed mycetozoan.
DNA Synthesis in Alveolar Cells of the Mammary Gland: Acceleration by Ovarian Hormones
Authors: Bresciani Francesco
Published: October 2006

In normal alveolar cells of the mammary gland of C3H/HeJ female mice, DNA synthesis lasts an average of 20.7 hours with a coefficient of variation of 26.6 percent. Treatment of the mice with 1 microgram of 17-β-estradiol and 1 milligram of progesterone per day for 3 to 4 days decreases the average duration to 10.7 hours and the coefficient of variation to 13.8 percent.
Protein Synthesis Enhanced in the Liver of Rats Force-Fed a Threonine-Devoid Diet
Authors: Sidransky Herschel , Staehelin Theophil , Verney Ethel
Published: October 2006

There is enhanced incorporation of leucine-C
14
into proteins in cell-free preparations from livers of young rats force-fed a threonine-devoid diet for 3 days. This increased protein synthesis in the liver is related predominantly to enhanced activity of ribosomes. The aggregates of liver ribosomes (ergosomes or polysomes) as measured in a sucrose gradient indicated a shift from lighter toward heavier ergosomes with a decrease in monomers.
Autonomic Mediation of the Effect of Raised Arterial Glucose upon Free Fatty Acids
Authors: Goodner C. J. , Tustison W. A.
Published: October 2006

The intravenous infusion of 600 milligrams of glucose over 30 minutes caused a 17 percent fall in the concentration of free fatty acids in arterial blood of subjects who had fasted overnight. This response to glucose was abolished in subjects treated previously with ganglionic or adrenergic blocking agents. Small amounts of insulin were secreted in response to these glucose infusions, but in insulin-dependent diabetics incapable of altering plasma insulin to any great extent, the effect of glucose upon free fatty acids could be obtained provided the subjects were primed with long-acting insulin before the infusions were begun. The response of free fatty acids to doses of glucose which elevated the concentration of glucose in arterial blood by only 3 mg percent and the blockade of this response by autonomic and adrenergic blocking agents suggest that centers in the central nervous system exist which are capable of responding to elevations of arterial glucose by inhibiting the sympathetic tone partially responsible for sustaining lipolysis in fasting.
Ceratocystis
Infection in Sweet Potato: Its Effect on Proteins, Isozymes, and Acquired Immunity
Authors: Weber Darrell J. , Stahmann Mark A.
Published: October 2006

Changes take place in the protein and isozyme patterns of tissue adjacent to cut surfaces of sweet potato roots infected by the fungus
Ceratocystis fimbriata
. Chromatography and gel electrophoresis of extracts from sections cut at known distances from a plane of infection showed that inoculation with a pathogenic or nonpathogenic isolate produced similar changes in several proteins and enzymes. Inoculation of a susceptible variety of sweet potato with the nonpathogenic isolate induced in a thin layer of tissue around the site of inoculation an acquired immunity to subsequent inoculation with the pathogen.
Crustacea: A Primitive Mediterranean Group also Occurs in North America
Authors: Maguire Bassett
Published: October 2006

A new species of the genus
Monodella
(class Crustacea, order Thermosbaenacea) has been found in a cave pool in Texas. Previously the order was believed to be restricted to the Mediterranean area. The new evidence indicates that the order is older than was believed, or that invasion of fresh or brackish water has occurred more than once within the order.
Epidermal Papillomas with Virus-like Particles in Flathead Sole,
Hippoglossoides elassodon
Authors: Wellings S. R. , Chuinard R. G.
Published: October 2006

Epidermal papillomas frequently occur on the external surfaces of flathead sole,
Hippoglossoides elassodon
, in the waters of San Juan Islands, Washington. Virus-like particles and associated granular bodies, also of possible viral nature, are commonly found in the neoplastic epithelial cells of these tumors. Similar structures are not observed in normal epidermis.
Galactosidase Action on Human Blood Group B Active
Escherichia coli
and Ox Red Cell Substances
Authors: Springer Georg F. , Nichols James H. , Callahan Hugh J.
Published: October 2006

The blood group B specificity of
Escherichia coli
O
86
antigen, a B specific oligosaccharide fraction from it, and the B activity of a preparation of an "infectious mononucleosis receptor" from cattle erythrocytes are destroyed by α-galactosidase from the coffee bean, as demonstrated for the
E. coli
antigen by three methods. Blood group H(O) activity appears simultaneously. Galactose is the only hexose released from all three substances.
Antigens Associated with a Tumor Virus: Rejection of Isogenic Skin Grafts from Leukemic Mice
Authors: Breyere Edward J. , Williams Louis B.
Published: October 2006

Skin grafts from leukemic adult Balb/c mice inoculated when newborn with a leukemia virus, showed evidence of rejection when transplanted to normal Balb/c mice or genetically compatible F
1
hybrids. Therefore, the "cellular" antigens associated with oncogenic viruses may not be limited to the induced tumors.
Adhesiveness of Spider Silk
Authors: Eisner Thomas , Alsop Rosalind , Ettershank George
Published: October 2006

Moths, by virtue of the loose scales that cover their wings and bodies, are admirably adapted to elude capture by orb-weaving spiders. Rather than sticking to the web, they may simply lose some of their scales to the viscid threads, and then fly on. Other insects, covered with detachable hairs or waxy powder, are similarly protected against entrapment. Quantitative data are presented on the adhesiveness of spider thread to insect cuticles of various kinds.
Genetic Disparity and Cancer Induction by Normal Tissue Implants in Amphibia
Authors: Ruben Laurens N. , Balls Michael
Published: October 2006

Fifty percent of the implants of normal adult
Triturus cristatus
kidney made into the forelimbs of immature but postmetamorphic
Xenopus laevis
hosts initiated the formation of lymphosarcoma at the site of implantation. Donor-host genetic disparity as it relates to the intensity of the reaction, when homografts, heterografts, and xenografts are compared, appears to be one of several factors which play a role in the post-embryonic induction of both lymphosarcomas in
Xenopus laevis
and accessory limb structures in
Triturus viridescens
.
Conjunctiva Contains Factor Inhibiting Growth of
Candida albicans
Authors: Kozinn Philip J. , Caroline Leona , Taschdjian Claire L.
Published: October 2006

Intact conjunctiva and conjunctival extracts have a strong inhibitory effect upon
Candida albicans
The fungistatic effect is not attributable to antimetabolic action and is not caused by lysozyme or tears, neither of which inhibit growth and viability of
Candida albicans
.
Telemetry of Homing Behavior by the Deermouse,
Peromyscus
Authors: Rawson Kenneth S. , Hartline Peter H.
Published: October 2006

Miniature transmitters (weighing 2.5 to 2.7 grams, including encapsulation) implanted subcutaneously in deermice
(Peromyscus)
radiate a pulsed signal at 27 megacycles per second which can be detected by a simple antenna at a distance of 45 meters. The radio signal indicates movements of the deermice, periods of activity, and the location of occupied nests. One mouse was traced as it returned to its nest 300 meters in 1 hour. This rate of homing is many times more rapid than the rate usually determined by conventional methods for tracking small terrestrial mammals.
Differentiation in Fern Gametophytes Treated with Purine and Pyrimidine Analogs
Authors: Raghavan V.
Published: October 2006

Analogs of the purines, adenine and guanine, and of the pyrimidines, cytosine and uracil, completely inhibited two-dimensional differentiation in the gametophytes of the fern,
Asplenium nidus
L. Analogs of thymine caused a nonspecific growth inhibition without suppressing two-dimensional growth. The effects of the analogs were reversed by the respective bases or their derivatives.
Dynamics of Epidemics of Plant Disease
Authors: Van der Plank J. E.
Published: October 2006

In the context of this discussion an epidemic is defined as an increase of disease in a field, forest, or other population of host plants. The susceptibility of the host plants, the virulence of the fungus or other pathogen, and the weather and other environmental conditions all affect the relative rate of increase. They do so by affecting the time it takes newly infected tissue to become infectious, the time tissue remains infectious, the infectiousness of infectious tissue, and the susceptibility of healthy tissue to infection. These factors operate throughout the epidemic. Two other factors become increasingly important as the epidemic proceeds: the proportion of healthy susceptible tissue remaining available for infection, and the degree of uniformity of the population of host plants and of their environment.
Tritiated Water as a Tool for Ecological Field Studies
Authors: Woods Frank W. , O'Neal Denny
Published: October 2006

Tritium was used to investigate the withdrawal by small trees of water from soil at three depths. Within 4 hours of placement at each depth, tritium was detected in the transpired water from nearby trees. On the 3rd day after application, 38 times more tritium (per unit volume) was present in transpired water drawn from soil at a depth of 0 to 30.5 centimeters than in water drawn from the 61- to 91.5-centimeter level.
Ribonucleic Acids of the Ilyanassa Embryo
Authors: Collier J. R.
Published: October 2006

From the
Ilyanassa
embryo an RNA component having a base composition similar to that of DNA has been separated by elution from a methylated albumin column. This material is judged to be a messenger RNA.
Exovagination of Newt Endoderm: Cell Affinities Altered by the Mesodermal Inducing Factor
Authors: Kocher-Becker Ursula , Tiedemann Heinz , Tiedemann Hildegard
Published: October 2006

Implantation of a highly purified mesodermal inducing factor in the blastocoel of early gastrulae results in the spreading of endoderm over the ectoderm. The effect can be explained by a change in cell affinities in the ectoderm, initiated by the mesodermal factor.
Choice Behavior in Rhesus Monkeys: Effect of Stimulation during the First Month of Life
Authors: Sackett Gene P. , Porter Mary , Holmes Hazel
Published: October 2006

Monkeys reared from birth away from other monkeys and handled by humans during the first month of life preferred humans to monkeys when tested at the age of 2 to 3 years. Animals having both early human handling and physical contact with other monkeys, or physical contact with other monkeys and no human handling, preferred monkeys. Subjects reared in complete isolation from humans and monkeys spent less time with either choice stimulus, but also preferred monkeys to humans.
Moloney Virus-Induced Leukemias of Mice: Measurement in vitro of Specific Antigen
Authors: Haughton G.
Published: October 2006

A modified test for cytotoxic antibody may be used to measure antibody directed against the tumor-specific antigen of leukemias of mice induced by Moloney virus; cell death is detected by liberation of
51
Cr. An inhibition test based on this technique permits accurate measurement of tumor-specific antigen in cells and subcellular fractions.
Constant Volume, Self-Filling Nanoliter Pipette: Construction and Calibration
Authors: Prager Denis J. , Bowman Robert L. , Vurek Gerald G.
Published: October 2006

Pipettes with volumes ranging from less than one nanoliter to 200 nanoliters can be constructed by means of a simple mechanical system and calibrated by radioisotope and fluorescence techniques. Biological fluids can be transferred with a repeatability of 1 percent by this self-filling pipette of constant volume.
Antibodies against the Component Polypeptide Chains of Bovine Insulin
Authors: Yagi Yasuo , Maier Patricia , Pressman David
Published: October 2006

Antibodies were produced in guinea pigs against A and B chains of bovine insulin; the chains were prepared by cleavage of all the disulfide bonds with sulfite. Antibodies against A chain reacted with A chain, but not with B chain or native insulin. Antibodies against B chain reacted strongly with both B chain and insulin, but not with A chain. Antibodies against insulin reacted strongly with insulin, weakly with B chain, and not at all with A chain. The results indicate that the insulin-reactive antibodies in antiserums to B chain and to insulin differ and are directed to differing individual antigenic regions of the insulin molecule.
Screw Dislocations in Graphite
Authors: Hennig G. R.
Published: October 2006

Graphite contains varying concentrations of screw dislocations whose Burgers vector parallels the
c
axis. Single crystals of natural graphite contain very few such dislocations; furthermore, their Burgers vector always exceeds 450 angstroms. Pyrolytic graphites annealed above 3000°C contain abundant screw dislocations, ranging from 10
6
to 5 × 10
8
per square centimeter in two different samples prepared by somewhat different methods. The Burgers vectors of these screws are predominantly 3.35 angstroms.
Complement and Hemolytic Antibody: Changes in Their Activity Induced by Mercaptoethanol
Authors: Frank Michael M. , Borsos Tibor , Rapp Herbert J.
Published: October 2006

Cell-bound complement components are not destroyed by mercaptoethanol. Destruction of cell-bound hemolytic antibody was prevented by cell-bound complement components. In the absence of cells, the complement components C′3 and C′4 were most susceptible to destruction by mercaptoethanol; C′1, C′1a, and C′2 were most resistant. Mercaptoethanol (0.01
M
) increases C′1 activity, and this increase is not due to activation of C′1 to C′1a. Destruction of some components required both mercaptoethanol and iodoacetamide treatment.
Lymphocyte Lifetime in Women
Authors: Norman Amos , Sasaki M. S. , Ottoman R. E. , Fingerhut A. G.
Published: October 2006

The lifetime of the lymphocyte in hematologically normal women is 530 ± 64 days. This estimate, made from studies on 25 women who had received radiation therapy for cervical carcinoma, is based on the rate of disappearance of lymphocytes with acentric chromosome fragments.
Mutagenicity of a Monofunctional Alkylating Agent Derivative of Acridine in
Neurospora
Authors: Brockman H. E. , Goben Wini
Published: October 2006

Purple adenine (
ad-3
) mutants induced in
Neurospora crassa
by 2-methoxy-6-chloro-9-(3-[ethyl-2-chloroethyl]aminopropylamino) acridine dihydrochloride (ICR-170) result from intragenic alterations. They are further characterized by low frequencies of leakiness, allelic complementation, and nonpolarized complementation patterns. These characteristics distinguish them from
ad-3
mutants induced by x-rays, nitrous acid, and 2-aminopurine.
Complement: Inactivation of Second Component by
p
-Hydroxymercuribenzoate
Authors: Leon Myron A.
Published: October 2006

p
-Hydroxymercuribenzoate inactivates the second component of complement whether it is in solution or is fixed to a sensitized erythrocyte together with the first and fourth components. Inactivation by the drug is blocked but not reversed by cysteine. Partial purification of the second component of complement is described.
Dolomitization of the Mid-Pacific Atolls
Authors: Berner Robert A.
Published: October 2006

The origin of the dolomite which occurs beneath the atolls of Funafuti, Kita-daitō-jima, and Eniwetok in the Pacific Ocean can be explained by the reaction of hypersaline brines with transported or buried reef skeletal material. Dolomitization could have taken place at the sediment surface in shallow restricted back-reef lagoons and tidal flats or below the surface by reflux action. Measurements of oxygen isotopes in samples of dolomite can be interpreted as indicating an origin from evaporated, isotopically-heavy sea water.
Tikal, Guatemala, and Emergent Maya Civilization
Authors: Coe William R.
Published: October 2006

It would be extravagant to claim that these pages have outlined meaningfully the early evolution of Tikal. Data have been provided largely for one excavation locus at a site which, for all its importance, merely has symptomatic value. We cannot claim to have, at present, sufficient material to document satisfyingly the conditions and products of community-wide living at any point in these early times. Present knowledge of Eb and Tzec ceramics and of all the usual archeological correlates (architecture and so on) is disturbingly incomplete. While we do have a good many data on residence throughout much of Preclassic time, considerably more information is needed before a solid evaluation of Preclassic Tikal society can be achieved. One can only hope that pending excavation programs will provide it. Yet, experience shows that probably only a tiny percentage of early cultural remains, regardless of their grandeur and importance at the time, would have survived the constant quest for construction fills to satisfy a seemingly interminable need to build and revamp.
Soviet-American Exchange
Authors: Greenberg Daniel S.
Published: October 2006

At hearings earlier this month on high-energy physics, held before the Joint Committee on Atomic Energy, Norman F. Ramsey, professor of physics at Harvard, was testifying when Representative Melvin Price (D-Ill.) told of a 1959 congressional tour of the Soviet high-energy laboratory at Dubna, and asked Ramsey for comment. The exchange went as follows:
Underwater Visual Discrimination by the California Sea Lion
Authors: Schusterman Ronald J. , Kellogg Winthrop N. , Rice Charles E.
Published: October 2006

Two captive sea lions (
Zalophus californianus
) presented with a series of size-discrimination tasks showed preferences for the smaller of two targets and gave virtually errorless performances despite changes in the form and relative size of the targets. Further tests revealed that they were capable of discriminating a size-difference ratio as small as 1.06:1.
Direct Visualization of the Dendritic and Receptive Fields of Directionally Selective Retinal Ganglion Cells
Authors: Yang Guang , Masland Richard H.
Published: October 2006

Optical methods were used to locate the cell bodies of directionally selective ganglion cells in isolated rabbit retinas. These neurons detect the direction in which images move across the retinal surface and transmit that information to the brain. The receptive field of each identified cell was determined, after which the cell was injected with Lucifer yellow. An image of the receptive field border was then projected onto the fluorescent image of the dendrites, allowing precise comparison between them. The size of the receptive field matched closely the size of the dendritic arbor of that cell. This result restricts the types of convergence that can be postulated in modeling the mechanism of retinal directional selectivity.
The Scientist in the Federal Service
Authors: Macy John W.
Published: October 2006

The plus factors of the federal personnel system for scientists may be summarized briefly as follows.

1) We have a modern, progressive personnel system which compares very favorably in most respects with that of a good private laboratory.

2) Although our pay scale may still be a little below that of private employment, great progress has been made in the past 3 years, and we are now catching up rather than falling further behind.

3) We do about as well as private employment with respect to benefits such as group life insurance, health insurance, and retirement, although some companies pay a larger share of the costs.

4) We have a generous and flexible leave system.

5) We are especially strong on promotion programs, incentive awards, and career development opportunities on the basis of merit and demonstrated competence.
Lewis Acidity of Polar Organic Solvents from Thermodynamic Measurements
Authors: Orye R. V. , Weimer R. F. , Prausnitz J. M.
Published: October 2006

A quantitative measure of the Lewis acidity of common organic solvents is given by the equilibrium constant for complex formation between the solvent and a π-donor such as an aromatic hydrocarbon. Lewis acidities are reported for 12 solvents from new distribution and vapor-pressure measurements.
Nonelectrolyte Transport in Muscle during Induced Protein Loss
Authors: Fenichel I. Robert , Horowitz Samuel B.
Published: October 2006

The accelerated loss of protein from
Rana pipiens
sartorius muscle following the induction of rigor by 100 millimolar 1-pentanol is not accompanied by increase in the rate constant for the efflux of urea. This observation is not readily accounted for by classical lipid-pore membrane permeability models. Alternative models are considered, in which protein and nonelectrolyte transport are dissociated; the dissociation could be (i) topological, due to compartmentalization, or (ii) functional, for example, if protein loss were due to change of the state of intracellular protein or if urea transport were limited by diffusion in the cytoplasm.
Split-Twig Figurines from Northern Arizona: New Radiocarbon Dates
Authors: Euler Robert C. , Olson Alan P.
Published: October 2006

Recently released radiocarbon dates for split-twig figurines from Marble Canyon, Arizona, are 4095 ± 100 years ago; they substantiate previously determined dates of 3530 ± 300 and 3100 ± 110 years ago. A recently excavated site in Walnut Canyon, Arizona, extends the geographical range of the figurines. The dates of samples from this site are 3500 ± 100 and 3880 ± 90 years ago. It is hypothesized that the figurines were magicoreligious artifacts related to the Pinto complex of the Desert Culture.
Myeloma Proteins and the Clinical Response to Melphalan Therapy
Authors: Bergsagel Daniel E. , Migliore Philip J. , Griffith Kenneth M.
Published: October 2006

Objective improvement after therapy with melphalan occurred in all patients producing only Bence Jones kappa proteins, in half of the patients with myeloma serum proteins, and in none of those producing only Bence Jones lambda proteins.
Human Skeletons of Tehuacán
Authors: Anderson James E.
Published: October 2006

The oldest series of human skeletons in the New World shows a high incidence of traumatic lesions during the early nomadic hunting and gathering phase, dental patterns which reflect the transition to an agricultural economy, some evidences of microevolution occurring in a local population, and one probable example of pre-Columbian syphilis.
Signal Detection in Fixed-Ratio Schedules
Authors: Rilling Mark , McDiarmid Colin
Published: October 2006

A psychophysical choice technique can be used to measure discrimination of the stimuli produced by two fixed-ratio schedules. As the difference between the two ratios is reduced, the number of errors in discrimination increases. The analysis differentiates between discrimination and response bias, which are frequently confused in animal psychophysics.
Muscle Volume Changes: Relation to the Active State
Authors: Baskin R. J. , Paolini P. J.
Published: October 2006

The volume of a frog sartorius muscle increases during a single twitch and subsequently decreases. The magnitude of volume change is 10
-5
cm
3
per gram of muscle. The time courses of change in volume and of onset of tension vary with temperature in a similar way, which implies a relation between the volume changes and the contraction mechanism. The character of the change depends upon the initial length of the muscle: the greatest decrease accompanies an isometric twitch at reference length. Treatment of the muscle with an iodide Ringer solution prolongs the active state and the volume change. These results suggest a correlation between the volume changes and the active state.
Eatometer: A Device for Continuous Recording of Free-Feeding Behavior
Authors: Fallon Daniel
Published: October 2006

Minor modifications of a commercially available food cup permit automatic recording of a rat's contacts with common dry food. It is thus possible to measure the frequency and duration of the "meals" that rats take over extended periods of time, and, in conjunction with existing devices for measuring drinking, to record contingencies between eating and drinking.
Photographic Documentation in Archeological Research: Increasing the Information Content
Authors: Erskine C. A.
Published: October 2006

Improved records of observations on ancient seals were obtained by photography of the objects at two angles in polarized light; positive transparencies in registered combination with the negative both reversed intaglio to relief and increased relief, contrast, and detail of the cut surface.
Birth Control: Academy Report Stresses Burdens of High Birth Rate among the Impoverished Here
Authors: Langer Elinor
Published: October 2006

In addition to the suggestions contained in the body of its report, the Academy population committee made several specific recommendations in three major spheres of activity—research, education and training, and services. Essentially the recommendations in all three areas can be summed up in a single word—"more." Specifically, in terms of research, the committee called for "all appropriate institutions, both private and governmental, to expand their efforts in the whole range of disciplines that contribute to knowledge of population matters, including demography, economics and other social sciences as well as biology, medicine and public health."
Immunoadsorbent for the Isolation of Purine-Specific Antibodies
Authors: Weetall H. H. , Weliky N.
Published: October 2006

An immunoadsorbent for the isolation of purine-specific antibody has been synthesized. The technique is applicable for isolating antibody to any purine or pyrimidine capable of being converted to a derivative which can be coupled to amine groups. The recovery of antibody from a serum sample is better than 82 percent, and the precipitability of the isolated antibody is as high as 89 percent.
Quinine-Resistant
Plasmodium berghei
in Mice
Authors: Thompson Paul E. , Bayles Anita , Olszewski Bronislawa , Waitz J. Allan
Published: October 2006

During induction of chloroquine resistance,
Plasmodium berghei
developed resistance to quinine administered in doses near the maximum amounts tolerated by mice. Resistant parasites did not form malarial pigment. Normal sensitivity to both quinine and chloroquine returned and pigment formation resumed during serial passage of the parasites through untreated mice.
Half-Lives of Argon-37, Argon-39, and Argon-42
Authors: Stoenner R. W. , Schaeffer O. A. , Katcoff S.
Published: October 2006

The half-lives of three argon isotopes have been carefully determined, with the following results: Ar
37
, 35.1 ± 0.1 days; Ar
39
, 269 ± 3 years; Ar
42
, 32.9 ± 1.1 years. By combining the Ar
42
value with earlier data, a cross section of 0.5 ± 0.1 barn is calculated for the reaction, with thermal neutrons, Ar
41
(n,γ)Ar
42
.
Response of the Rabbit Oviduct to a Tissue Adhesive
Authors: Corfman Philip A. , Richart Ralph M. , Taylor Howard C.
Published: October 2006

Sexual sterilization of mammals by the production of an obstruction at the tubo-uterine junction has been reevaluated experimentally. The application of 0.15 ml of methyl 2-cyanoacrylate monomere to the junction in rabbits produced, at intervals from 1 to 6 weeks later, histological, hydrodynamic, and functional evidence of tubal obstruction.
Collagen: Structural Studies Based on the Cleavage of Methionyl Bonds
Authors: Bornstein Paul , Piez Karl A.
Published: October 2006

Eighteen peptides from the α1 fraction and eight from the α2 fraction of rat skin collagen cleaved with cyanogen bromide have been identified by chromatography on carboxymethyl cellulose. The isolated peptides show wide differences in amino acid composition, and their molecular weights vary from several thousand to about 23,000. The data indicate that there are two different chains in the α1 fraction, demonstrating the nonidentity of all three α-chains. The primary structure of each chain appears to be unique throughout its length.
Pseudo Superglacial Till
Authors: Howard Arthur D.
Published: October 2006

A thin layer of coarse till overlies clay-rich till in northwestern North Dakota. That the thin layer is not a superglacial facies of the underlying clayey till is indicated by (i) geomorphic relations; (ii) contrasted lithologies; (iii) restricted area of exposure; (iv) absence of a similar deposit on a younger clayey till in a comparable topographic environment; (v) presence of a probable paleosol; (vi) an intervening unconformity; and (vii) occurrence of clayey facies of the upper deposit. The deposit is believed to represent a younger till.
Nervous System Research with Computers
Authors: McCann G. D.
Published: October 2006

The experimental system described above has been in full-scale operation now for about one year. It has been possible in this short period only to begin the exploration of the potentialities of the system for aiding nervous system research. The most intensively developed programs have been those on the insect and on human vision and eye movements. In both of these programs the facility has permitted new research techniques which have provided answers to important questions, answers which would have been unobtainable without such a data-processing and control system.
Cosmogenic Radionuclides in the Bondoc Meteorite
Authors: Cressy Phillip J. , Shedlovsky Julian P.
Published: October 2006

Long-lived cosmogenic radionuclides were measured in the stone phase and in a mechanically separated metallic nodule from a fragment of the Bondoc mesosiderite. Activity levels of the various radionuclides in both phases, along with results of mass-spectrometric measurements of rare-gas isotopes in the stone phase, indicate that heavy shielding was the chief cause of the low specific activities observed.
Cryogenic Cooling by Noncondensible-Gas Injection
Authors: Lytle Farrel W. , Stoner J. Thomas
Published: October 2006

Temperature control of various cryogenic liquids in the range from their boiling points to near or below their freezing points has been achieved by injecting a noncondensing gas, helium. The process is more easily accomplished than the usual vapor-pumping technique and is applicable in the range from 15° to 300°K. Interesting ice formations were observed in liquid argon.
Complement: Increased Efficiency of the Second Component after Treatment with Iodoacetamide
Authors: Polley Margaret J. , Müller-Eberhard Hans J.
Published: October 2006

The apparent activity of the second component of human complement was enhanced by treatment of the purified protein with iodoacetamide. By contrast, treatment with iodoacetic acid or
p
-chloromercuribenzoate led to inactivation. Treatment with iodoacetamide prevented the effect of
p
-chloromercuribenzoate and vice versa. Enhanced activity was partly due to increased stability of the otherwise labile intermediate complex consisting of erythrocytes, antibody, and the first, second, and fourth components of complement.
Trematode Parasitism and Polymorphism in a Marine Snail
Authors: Ewers Wm. H. , Rose C. R.
Published: October 2006

Velacumantus australis
is a common Australian snail which harbors several larval trematodes. Many populations have a small proportion of banded shells. Analysis of three samples from a coastal lake shows that banded snails are less likely to harbor larval trematodes than unbanded snails.
Two-Stage Paired-Associate Learning and Eye Movements
Authors: McCormack P. D. , Haltrecht E. J.
Published: October 2006

Eye movements of 20 male students were photographed continuously throughout the course of their learning verbal paired-associates. As learning progressed, proportionately less and less time was spent scanning the response when the stimulus and response were presented together. These findings are interpreted as supporting a two-stage theory of verbal learning.
Territorial Behavior among Puku in Zambia
Authors: de Vos A.
Published: October 2006

Territorial behavior of a species of antelope, the puku,
Adenota vardoni
(Livingstone) consists of the defense by males during the mating season of relatively widely spaced territories on a "territorial ground." Females wander about on this area for the purpose of mating.
Ultrastructure of Vegetative and Reproductive Apices of
Chenopodium album
Authors: Gifford Ernest M. , Stewart Kenneth D.
Published: October 2006

The apical meristem of the vegetative shoot of
Chenopodium album
(lamb's-quarters) exhibits alterations in cytoplasmic structure as early as 3 hours after the plant has been subjected to one photoinductive cycle which promotes flowering. The endoplasmic reticulum shows an altered distribution and there is evidence of an increase in acid phosphatase production. Dictyosomes increase in number per cell by the end of the second inductive cycle.
Precambrian Glaciated Surface Beneath the Gowganda Formation, Lake Timagami, Ontario
Authors: Schenk Paul E.
Published: October 2006

Glacial deposition of the Gowganda formation is established by the discovery of an extensive, well-marked, glaciated, basal contact surface. This surface is exposed near the southeastern end of Lake Timagami, northern Ontario. The Precambrian ice sheet advanced three times from the northeast over the area.
Ribosomal-RNA Synthesis in the Absence of Ribosome Synthesis in Germinating Cotton Seeds
Authors: Waters Larry , Dure Leon
Published: October 2006

Cotton embryos after 72 hours of germination synthesize ribosomal RNA that does not become incorporated into ribosomes and that is very stable. This RNA has many characteristics similar to those of newly synthesized ribosomal RNA of bacteria.
Induced Hypersensitivity to Cold
Authors: Selye Hans
Published: October 2006

Extreme hypersensitivity to cold can be induced in the rat by a single subcutaneous injection of carrageenin. In animals so treated, exposure to cold induces necrotizing thrombohemorrhagic lesions in the nose, paws, and tail, accompanied by renal lesions resembling those of the generalized Sanarelli-Shwartzman phenomenon. The same treatment elicits hemorrhagic necroses of transplants of Murphy lymphosarcomas in rats.
Cradleboard Hoods, Not Corsets
Authors: Carlson Roy L. , Armelagos George J.
Published: October 2006

Utmost caution should be exercised in interpreting archeological data out of context. Certain artifacts described in the literature on human paleopathology as therapeutic corsets are in fact hoods for cradleboards. Close cooperation among specialists in various disciplines is desirable in reconstructing aspects of prehistoric culture.
Double Beta-Lipoprotein: A New Genetic Variant in Man
Authors: Seegers Winnifred , Hirschhorn Kurt , Burnett Lee , Robson Elizabeth , Harris Harry
Published: October 2006

A β-lipoprotein variant, in which two bands appear after electrophoresis, has been found in three generations of a family. The variant, immunologically also a β-lipoprotein, differs in molecular size, density, and charge from normal β-lipoprotein. Individuals showing the variant appear to be heterozygous for an uncommon mutant gene.
Blepharisma intermedium
: Ultraviolet Resistance of Pigmented and Albino Clones
Authors: Giese Arthur C.
Published: October 2006

An albino mutant of
Blepharisma intermedium
is much more sensitive (on the basis of time to regeneration of transected cells) to short-wavelength ultraviolet radiation than the wild type (containing a reddish pigment) from which the mutant derived. In the wild type, absorption of ultraviolet light by the pigment present in the outer surface of the cell presumably reduces the intensity of the radiation impinging on the vulnerable interior.
Orientation of
Ambystoma maculatum
: Movements to and from Breeding Ponds
Authors: Shoop C. Robert
Published: October 2006

Migrating
Ambystoma maculatum
tend to utilize the same track on entering and leaving breeding ponds. The movements are usually accomplished at night in rain, fog, or cloudy weather when visible celestial cues may not be available. The sensory basis for the orienting ability is unknown.
Oxygen-Hemoglobin System: A Model for Facilitated Membranous Transport
Authors: Zilversmit D. B.
Published: October 2006

Enhanced transport of oxygen in a Millipore filter containing a solution of hemoglobin can be accounted for by the diffusion of free oxygen as well as of hemoglobin-bound oxygen. A model shows that, at oxygen tensions at which the hemoglobin is fully saturated in a portion of the membrane, the enhanced transport is due to a steeper gradient for free oxygen, whereas in the rest of the membrane an "(oxy)hemoglobin shuttle" operates. A similar model may be useful for explaining facilitated diffusion in other systems.
Temperature-Sensitive Repression of Staphylococcal Penicillinase
Authors: Cohen Sidney , Sweeney Helen , Leitner Felix
Published: October 2006

In eight highly inducible strains of
Staphylococcus aureus
repression of the formation of penicillinase was temperature-sensitive under conditions suggesting direct thermal inactivation of the repressor. Restoration of repression required protein synthesis. These strains were resistant to benzylpenicillin and to many other antibiotics. One auxotrophic mutant had greatly reduced temperature sensitivity but was still normally inducible. Six strains were relatively poorly inducible, exhibited a proportionately smaller increase in enzyme after exposure to elevated temperature, and were sensitive to antibiotics other than benzylpenicillin. Temperature sensitivity may be a useful character in studies of the physiology and genetics of the repression of staphylococcal penicillinase.
Vocalization Evoked from the Optic Lobe of a Songbird
Authors: Brown Jerram L.
Published: October 2006

Vocalizations from songbirds have been evoked by electrical stimulation of the torus. These vocalizations resemble the normal alarm and scolding calls of the species. The torus of the birds appears to correspond functionally and anatomically to the mammalian central gray matter.
Simple Microcentrifuge for Use in the Field
Authors: Holmstedt Bo
Published: October 2006

A novel, simply made, hand-powered microcentrifuge has been developed for use in the field. It handles as many as eight samples simultaneously. The principal materials are sheet nylon, polyester cord, and polyethylene tubing. Maximum speed of the centrifuge is 10,000 revolutions per minute; maximum radial acceleration, 8400
g
. Among other uses, the centrifuge serves to obtain plasma for immunoelectrophoresis and flocculation and agglutination tests and for determination of plasma cholinesterase and total solids (refractometrically). Hematocrit values may be obtained and blood parasites concentrated.