bluuebunny/crossref_metadata_2025 huggingface dataset:
Porifera: Sudden Sperm Release by Tropical Demospongiae
Authors: Reiswig Henry M.
Published: October 2006

Three tropical marine demosponges inhabiting the deep coral reefs of Jamaica expel immense clouds of milky fluid from exhalant apertures. Analysis of samples shows this fluid to contain mature male gametes. The behavior is an individual or a population event in different species.
Prolactin: Evidence That It Is Separate from Growth Hormone in Human Blood
Authors: Frantz Andrew G. , Kleinberg David L.
Published: October 2006

A highly sensitive bioassay has been developed for prolactin, which uses a mammalian end organ and which is capable of measuring the hormone in unextracted human plasma. High prolactin activity, largely neutralizable with antiserum to human growth hormone, is stimulated along with high immunoassayable growth hormone by insulin-induced hypoglycemia. High prolactin activity, not neutralizable with antiserum to growth hormone, exists with low concentrations of plasma growth hormone in postpartum patients and patients with galactorrhea.
Condensation Nuclei: Production of Very Large Numbers in Country Air
Authors: Schaefer Vincent J.
Published: October 2006

When relatively clean country air is exposed to the saturated vapor of iodine or turpentine, very large numbers of condensation nuclei develop. It is believed that such air contains clusters of molecules that are polymerized by the vapor of turpentine or iodine to form nuclei.
Transfer of Interferon-Producing Macrophages: New Approach to Viral Chemotherapy
Authors: Glasgow Lowell A.
Published: October 2006

Mice were protected from infection with Semliki Forest virus and encephalomyocarditis virus by the transfer of peritoneal macrophages that were stimulated to produce interferon in vitro by exposure to a nonreplicating virus. This method of therapy was also utilized in animals infected with encephalomyocarditis virus after onset of clinical signs. Of these animals 40 percent recovered, but only 9 percent of the control group recovered.
Tyrosine Transaminase Induction by Dexamethasone in a New Rat Liver Cell Line
Authors: Gerschenson L. E. , Andersson Myrna , Molson Jill , Okigaki Tohru
Published: October 2006

A cell line derived from normal, adult rat liver has been established; the cells are similar to hepatocytes, as shown by electron microscopy. The addition of dexamethasone to the culture medium induced a three- to sixfold increase in the specific activity of tyrosine α-ketoglutarate transaminase; this increase was inhibited by the simultaneous addition of cycloheximide or actinomycin D. The latter, when added to cells given prior treatment with dexamethasone, further enhanced the transaminase activity. Contact-inhibited cells showed a lower response to dexamethasone than exponentially growing cells.
Starvation in Human Pregnancy: Hypoglycemia, Hypoinsulinemia, and Hyperketonemia
Authors: Felig Philip , Lynch Vincent
Published: October 2006

In women fasted during the second trimester of pregnancy, concentrations of glucose and insulin in the plasma fell to a greater extent and ketone acid concentrations in the blood rose more rapidly than in nonpregnant controls. Nitrogen excretion in the urine, particularly ammonia, was increased in the pregnant group. Continuous glucose utilization by the conceptus may exaggerate and accelerate the metabolic consequences of starvation.
Bottom Velocity Observations Directly under the Gulf Stream
Authors: Schmitz William J. , Robinson A. R. , Fuglister F. C.
Published: October 2006

Speeds as high as 44 centimeters per second were observed 200 meters above the ocean bottom under the Gulf Stream at 70°W longitude and were associated with time-dependent motion that had a speed range of 40 centimeters per second and a time scale of about 30 days. These deep current fluctuations appear to be coupled with fluctuations in the surface position of the Stream and with surface and bottom current fluctuations 200 kilometers to the north.
Summary of Arguments for a Hot Moon
Authors: Baldwin Ralph B.
Published: October 2006

Analysis of physical and chemical observations shows that the interior of the moon is now and always has been hot. It is close to the melting point at each level beneath a cool outer zone.
Auroral-Particle Precipitation and Trapping Caused by Electrostatic Double Layers in the Ionosphere
Authors: Albert R. D. , Lindstrom P. J.
Published: October 2006

Interpretation of high-resolution angular distribution measurements of the primary auroral electron flux detected by a rocket probe launched into a visible aurora from Fort Churchill in the fall of 1966 leads to the following conclusions. The auroral electron flux is nearly monoenergetic and has a quasi-trapped as well as a precipitating component. The quasi-trapped flux appears to be limited to a region defined by magnetic-mirror points and multiple electrostatic double layers in the ionosphere. The electrostatic field of the double-layer distribution enhances the aurora by lowering the magnetic-mirror points and supplying energy to the primary auroral electrons.
Increased Urinary Excretion of Cyclic Guanosine Monophosphate in Rats Bearing Morris Hepatoma 3924A
Authors: Murad Ferid , Kimura Hiroshi , Hopkins Harold A. , Looney William B. , Kovacs Charles J.
Published: October 2006

Urinary excretion of cyclic guanosine monophosphate (GMP) increased in rats bearing Morris hepatoma 3924A, and a correlation coefficient of .842 was observed comparing nucleotide excretion and tumor size. Irradiation of tumor or 5-fluorouracil administration delayed the increases in urinary cyclic GMP and tumor size. Surgical removal of tumors resulted in a rapid decline in cyclic GMP excretion to baseline levels. Cyclic adenosine monophosphate excretion was not altered by implantation, irradiation, or excision of tumor.
Epithelial Origin of Polyoma Salivary Tumors in Mice: Evidence Based on Chromosome-Marked Cells
Authors: Dawe C. J. , Whang-Peng J. , Morgan W. D. , Hearon E. C. , Knutsen T.
Published: October 2006

Trypsin dissection of epithelium from mesenchyme of salivary gland rudiments allows reassembly of glands having either epithelium or mesenchyme selectively marked by T
6
chromosomes. Virus-induced tumors in such glands invariably bear the karyotype of the epithelial component. The method solves a specific example from a group of classical problems concerning epithelial as opposed to mesenchymal origin of neoplasms.
Sodium and Potassium Activities in Normal and "Sodium-Rich" Frog Skeletal Muscle
Authors: Armstrong W. McD. , Lee Chin O.
Published: October 2006

In frog sartorius muscles immersed for 2 hours at 26°C in normal Ringer solution, the intrafiber potassium concentration,
C
K
(in millimoles per liter), was 123 ± 2 (mean value plus or minus standard error), and the potassium activity,
a
K
(in millimoles per liter), was 90 ± 1.0. The corresponding sodium concentration and activity were 20 ± 1 and 6.5 ± 0.4, respectively. After overnight immersion in K
+
-free Ringer solution the values were:
C
K
, 97 ± 2;
a
K
, 81.5 ± 1.6;
C
Na
, 47 ± 2; and
a
Na
, 11.2 ± 0.6. The changes in
a
K
and
a
Na
during storage were not consistent with an exchange between predominantly "free" fiber K
+
and external Na
+
. These results suggest that the Na
+
taken up during overnight immersion largely replaced adsorbed or sequestered K
+
in the fibers.
Lunar Metallic Particle ("Mini-Moon"): An Interpretation
Authors: McKay David S. , Carter James L. , Greenwood William R.
Published: October 2006

A troilite-rich nickel-iron particle ("mini-moon") recovered from the moon may be a mound detached from a sphere of silicate glass. Erosion and pitting of the particle may have been caused by passage through a cloud of hot gas and particulate matter formed by meteorite impact on the lunar surface. This explanation is in contrast to the theory that the particle was meteoritically derived molten material that was furrowed during solidification after lunar impact, subsequently pitted by high-velocity particles, and then abraded and polished by drifting dust while on the lunar surface.
Allergic Encephalomyelitis: New Form Featuring Polymorphonuclear Leukocytes
Authors: Levine Seymour , Sowinski Richard
Published: October 2006

The passive transfer of allergic encephalomyelitis can be produced in a single day. In work described, the procedure was made to coincide with a transient drug-induced deficiency of lymphocytes. As a result, the lesions of this autoimmune disease contained a predominance of polymorphonuclear leukocytes instead of the usual mononuclear cells. Not only is this a new histologic form of the disease, but the ready recognition of polymorphonuclears as reactive cells provides a powerful new tool for investigating the roles of immunologically specific effector cells and nonspecific reactive cells in production of tissue damage.
Insect Control by Genetic Manipulation of Natural Populations
Authors: Whitten M. J.
Published: October 2006

The possible use of chromosome rearrangements is considered as a means for introducing genes into insect populations for their own control. The release of laboratory-constructed strains differing from the field population for a number of chromosome interchanges should create an unstable situation leading to the rapid replacement of the field population. This replacement should allow introduction of genes for insecticide susceptibility, cold sensitivity, or the like. The process would produce sterile hybrids while the genetic displacement occurs which itself will contribute to a reduction in pest numbers.
Sea Urchin Embryos Are Permeable to Actinomycin
Authors: Greenhouse Gerald A. , Hynes Richard O. , Gross Paul R.
Published: October 2006

When eggs and cleaving embryos of the sea urchin are exposed to [
3
H]actinomycin D, they become radioactive, and autoradiograms show that the radioactivity is inside the cells. At midcleavage, nuclei are more radioactive than cytoplasm. Extraction and chromatography of the intracellular labeled compounds identify them as actinomycin D and a water-soluble derivative. Conversion does not take place outside the cells. Treatment of embryos for 90 minutes with actinomycin D inhibits synthesis of RNA by more than 90 percent, leaving unaffected turnover of the pCpCpA terminals in transfer RNA. These data justify earlier interpretations of actinomycin experiments with embryos and justify use of the drug as a tool in the analysis of gene expression.
Visual Attention in the Tree Shrew: An Ablation Study of the Striate and Extrastriate Visual Cortex
Authors: Killackey H. , Diamond I. T.
Published: October 2006

Removal of the striate area in tree shrews results in increased distractibility, which prevents the animals from learning to discriminate form when hue is an irrelevant and distracting cue. Removal of the extrastriate visual cortex results in the reciprocal deficit: an increase in perseveration manifested by an inability to shift attention when irrelevant dimensions are made relevant.
Embryonic and Neoplastic Cell Surfaces: Availability of Receptors for Concanavalin A and Wheat Germ Agglutinin
Authors: Moscona A. A.
Published: October 2006

Embryonic tissue cells dissociated with ethylenediaminetetraacetate are readily agglutinated by the carbohydrate-binding protein concanavalin A. In this property, they resemble transformed, neoplastic cells; and they differ from untransformed adult cells, which are agglutinated by concanavalin A only after their receptors are unmasked by proteolytic treatment. Receptor sites for wheat germ agglutinin are also present on the surface of embryonic cells, but in a masked form, as on untransformed adult culture cells; they can be unmasked by treatment of the cells with trypsin. Concanavalin A binding sites on embryonic cells may function in cell contact and cell organization during embryonic morphogenesis and differentiation and later become masked in adult cells. The unmasking of these sites in neoplastic cells may represent a return, in this respect, to a condition resembling that of embryonic cells and may be related to cell mobility associated with infiltration and metastasis.
Erythrocyte Metabolism: Interaction with Oxygen Transport
Authors: Brewer George J. , Eaton John W.
Published: October 2006

Studies of the interactions between the metabolism and the function of the red cell have shown the importance of the red cell's metabolism in contributing to the maintenance of adequate oxygen delivery. Some of the phosphorylated intermediates of glycolysis, especially DPG, are now known to reduce the affinity of hemoglobin for oxygen. Current evidence indicates that this phenomenon is due to the effects of the binding of DPG to the β-chains of deoxyhemoglobin. It appears that increases in red cell concentrations of DPG commonly occur during hypoxia, and that these increases (as well as normal physiological variation) significantly enhance oxygen transport. Artificial manipulation of erythrocyte metabolism may soon prove to be of great clinical usefulness in the treatment of a great variety of disorders which limit oxygen transport.
Cycloheximide: Its Effects on Activity Are Dissociable from Its Effects on Memory
Authors: Segal David S. , Squire Larry R. , Barondes Samuel H.
Published: October 2006

Cycloheximide, when injected subcutaneously or intracerebrally, produces changes in the activity level of mice. Isocycloheximide, injected intracerebrally, produces identical effects on activity, but it does not produce inhibition of cerebral protein synthesis or amnesia. Amphetamine, in doses that can antagonize the amnesic action of cycloheximide, does not antagonize the effect of cycloheximide on activity. Effects of cycloheximide on activity do not appear to be responsible for its amnesic action.
Nucleotide Sequence of the "Denaturable" Leucine Transfer RNA from Yeast
Authors: Kowalski Steven , Yamane Tetsuo , Fresco Jacques R.
Published: October 2006

The nucleotide sequence of "denaturable" leucine acceptor transfer RNA (tRNA
Leu
3
) from baker's yeast was determined on
32
P-labeled material. The molecule is 85 nucleotides long and can be folded into the "cloverleaf" model for secondary structure. The basis on which the sequence was deduced from the products of complete enzymatic digestion, prior to its unambiguous determination, is presented.
Does DDT Inhibit Carbonic Anhydrase?
Authors: Dvorchik Barry H. , Istin Michael , Maren Thomas H.
Published: October 2006

At a concentration of 50 to 100 micrograms per milliliter,
p,p
'-DDT (and
p,p
'-DDE) did not inhibit the rate of hydration or dehydration of carbon dioxide by carbonic anhydrase. At concentrations greater than 500 micrograms per milliliter, partial inhibition of the rate of dehydration of carbonic acid was observed, but this involved precipitation of drug in the reaction vessel. This degree of inhibition suggests that DDT may not inhibit carbonic anhydrase effectively at the usual concentrations found in tissue after exposure of organisms to DDT in the environment.
Sugar Transport: Effect of Temperature on Concentrative Uptake of α-Methylglucoside by Kidney Cortex Slices
Authors: McNamara Pamela , Rea Claire , Segal Stanton
Published: October 2006

The ability of renal cortical slices to accumulate a monosaccharide is enhanced at temperatures below 37°C. Increase in concentration gradients occurs despite a decrease in total sugar flux. The apparent explanation for this paradox is a proportionally greater inhibition of efflux.
Alleviating the Shortage of Physicians
Authors: Harrington William J. , Whelan William J. , Fogel Bernard J. , Papper E. M.
Published: October 2006

A curriculum is described whereby qualified Ph.D's can become M.D.'s within a period of 18 to 24 months. It is feasible and logical not only for us, but for other schools of medicine. It is our belief that adequate safeguards have been included to preserve high quality in education while responding to the need not only for more physicians, but also for improved utilization of some of our best-trained manpower.
Runoff of Deicing Salt: Effect on Irondequoit Bay, Rochester, New York
Authors: Bubeck Robert C. , Diment William H. , Deck Bruce L. , Baldwin Alton L. , Lipton Stewart D.
Published: October 2006

Salt used for deicing the streets near Rochester, New York, has increased the chloride concentration in Irondequoit Bay at least fivefold during the past two decades. During the winter of 1969-70 the quantity and salinity of the dense runoff that accumulated on the bottom of the bay was sufficient to prevent complete vertical mixing of the bay during the spring. Comparison with 1939 conditions indicates that the period of summer stratification has been prolonged a month by the density gradient imposed by the salt runoff.
Compositional Relatedness between Histocompatibility Antigens and Human Serum Lipoproteins
Authors: Berg Kåre
Published: October 2006

Human histocompatibility antigens and the protein part of Lp(a) lipoprotein and low density lipoprotein of human serum appear to be related when the amino acid compositions are compared. The Lp(a) lipoprotein appears to be closely related also to murine H-2
d
antigen. The results support the concept of a relation between serum lipoproteins and histocompatibility antigens on cell membranes.
X-ray Diffraction Patterns of Transfer RNA Consistent with the Presence of Short Parallel Helices in the Molecule
Authors: Sakurai T. , Rao S. T. , Rubin J. , Sundaralingam M.
Published: October 2006

X-ray diffraction data of yeast formylmethionine transfer RNA,
Escherichia coli
phenylalanine transfer RNA, and
Escherichia coli
arginine transfer RNA single crystals are compared with the Fourier transform of a helix. The results are consistent with the presence of short parallel double helical segments in the transfer RNA molecules.
Ovarian Maturation in Stable Flies: Inhibition by 20-Hydroxyecdysone
Authors: Wright James E. , Chamberlain W. F. , Barrett C. C.
Published: October 2006

The steroid 20-hydroxyecdysone when given by mouth inhibits ovarian maturation in the stable fly,
Stomoxys calcitrans
(L.). by preventing lipid synthesis necessary for vitellogenesis in the developing oocyte.
Snake Infrared Receptors: Thermal or Photochemical Mechanism?
Authors: Harris John F. , Gamow R. Igor
Published: October 2006

It appears that the two most sensitive infrared receptors known in the biological world are found in two widely different families of snakes, the pit vipers and the boas. After an infrared stimulus from a carbon dioxide laser, which has a monochromatic output at 10.6 micrometers, we find evoked potentials in boas with chronically implanted electrodes. Our data suggest that the receptors operate on a thermal principle.
Covalent Enzyme-Substrate Intermediates
Authors: Bell Robert M. , Koshland D. E.
Published: October 2006

A literature search reveals 60 cases in which there is strong evidence for covalent enzyme-substrate intermediates.
Butterfly Feeding on Lycopsid
Authors: Singer Michael C. , Ehrlich Paul R. , Gilbert Lawrence E.
Published: October 2006

Larvae of
Euptychia westwoodi
feed on
Selaginella
, a lycopsid. This is the first feeding record in the Satyrinae outside the monocotyledons and one of the few records of a butterfly feeding on other than a seed plant. Clues to possible evolutionary origins of this habit are found in the oviposition behavior of other
Euptychia
species.
Maternal-Fetal Interaction and Immunological Memory
Authors: Gill Thomas J. , Kunz Heinz W. , Bernard Colette F.
Published: October 2006

Female rats of the poorly responding, inbred F344 strain were immunized with poly(Glu
52
Lys
33
Tyr
15
) aggregated with methylated bovine serum albumin, and then they were mated. The first and second litters in the F
1
generation and in the F
2
generation showed an enhanced immune response. When polylysine was used as the aggregating agent, enhancement occurred in only the first litter of the F
1
generation and in the F
2
generation. In both cases, antigen was transmitted from the immunized female to her offspring, where it localized in the bone marrow and, in a few cases, in the thymus and spleen also. The transplacental passage of antigen is probably the basis for the enhanced antibody response, which is a manifestation of immunological memory.
Primary Structure of the Human Chorionic Somatomammotropin (HCS) Molecule
Authors: Li Choh Hao , Dixon Jonathan S. , Chung David
Published: October 2006

The complete amino acid sequence of the human chorionic somatomammotropin molecule been proposed; and then compared with that of human growth hormone and ovine lactogenic hormone.
Theta-Bearing and Complement-Receptor Lymphocytes Are Distinct Populations of Cells
Authors: Bianco Celso , Nussenzweig Victor
Published: October 2006

In the mouse, most (or all) complement-receptor lymphocytes and theta-bearing lymphocytes are part of nonoverlapping populations of cells. This finding validates the use of these membrane markers to characterize populations of lymphocytes. In addition, it is probable that, although receptors for complement and membrane-bound immunoglobulins coexist on the same lymphoid cells, these markers are located at separate sites on the membrane.
Antiviral Activity of Polyribocytidylic Acid in Cells Primed with Polyriboinosinic Acid
Authors: De Clercq E. , De Somer P.
Published: October 2006

Separate administration of polyribocytidylic acid [poly(rC)] and polyriboinosinic acid [poly(rI)] to cell cultures in vitro resulted in an antiviral activity identical to or greater than that resulting from addition of the poly(rI) ⋅ poly(rC) complex. Priming of cells with poly(rI), followed by treatment with poly(rC), gave a consistently greater antiviral activity than poly(rI) ⋅ poly(rC) itself. This priming effect was obtained in several cell cultures challenged with different viruses. In vivo, the antiviral activity of poly(rI) ⋅ poly(rC) was only partially restored if poly(rI) and poly(rC) were injected separately; prior injection of poly(rI) proved superior in restoring this antiviral activity as compared to prior injection of poly(rC).
Enzymatic Modification of Transfer RNA
Authors: Söll Dieter
Published: October 2006

The molecular events leading to the synthesis of mature tRNA are only now becoming amenable to experimental study. In bacterial and mammalian cells tRNA genes are transcribed into precursor tRNA. These molecules, when isolated, contain additional nucleotides at both ends of the mature tRNA and lack most modified nucleosides. Presumably, specific nucleases ("trimming" enzymes) cut the precursor to proper tRNA size. The C-C-A nucleotide sequence of the amino acid acceptor end common to all tRNA's does not seem to be coded by tRNA genes, and may be added to the trimmed molecules by the tRNA-CMP-AMP-pyrophosphorylase. Modifications at the polynucleotide level of the heterocyclic bases or the sugar residues give rise to the modified nucleosides in tRNA. Although newly available substrates have allowed the detection of more of the enzymes involved in these reactions, there is still no knowledge about the sequence of modification or trimming events leading to the synthesis of active tRNA. Progress in these studies may not be easy because enzyme preparations free of nucleases or other tRNA modifying enzymes are required.

The role of the modified nucleosides in the biological functions of tRNA is still unknown. Possibly pseudouridine is required for ribosome mediated protein synthesis; some other modified nucleosides in tRNA are not required for this reaction, but may enhance its rate. What might be the role of the large variety of modified nucleosides in tRNA? One is tempted to speculate that such nucleosides are important in other cellular processes in which tRNA is thought to participate such as virus infection, cell differentiation, and hormone action. Mutants in a number of tRNA-modifying enzymes are needed in order to extend our knowledge of their purpose and of tRNA involvement in other biological processes. But unless tRNA-modifying enzymes specific for a particular tRNA species exist, no simple selection procedure can be devised. Possibly some of the regulatory mutants of amino acid biosynthesis may prove to affect tRNA-modifying enzymes.

Transfer RNA's are macromolecules well suited for the study of nucleic acid-protein interactions. The tRNA molecules are structurally very similar, and they interact with a large number of enzymes or protein factors. Each aminoacyl-tRNA synthetase, for instance, very precisely recognizes a set of cognate isoacceptor tRNA's. The availability of the tRNA-modifying enzymes adds another dimension to the problem of the nature of specific recognition of tRNA by proteins. There are some tRNA-modifying enzymes, such as the uracil-tRNA methylase, which may recognize all tRNA species, while others, such as the isopentenyl-tRNA transferase, probably recognize only a selected set of tRNA molecules, even with different amino acid accepting capacities. With well-characterized RNA precursor and tRNA molecules we can hope to delineate those features of primary, secondary, and tertiary structure involved in the specific interactions of tRNA with these enzymes.
Acetylcholine Binding to
Torpedo
Electroplax: Relationship to Acetylcholine Receptors
Authors: Eldefrawi Mohyee E. , Britten Alan G. , Eldefrawi Amira T.
Published: October 2006

Binding of [
3
H]acetylcholine to a particulate fraction of Torpedo electroplax was measured by equilibrium dialysis. Two high-affinity sites present on phospholipoproteins bound acetylcholine reversibly, and binding was blocked by nicotinic drugs. Characteristics of this binding suggest that these phospholipoproteins may be acetylcholine receptors.
Rifting in Iceland: New Geodetic Data
Authors: Decker R. W. , Einarsson Páll , Mohr P. A.
Published: October 2006

Small but measurable lengthening of several survey lines within the eastern rift zone of Iceland occurred between 1967 and 1970. The changes can be interpreted as a widening of the rift by 6 to 7 centimeters, possibly during the 1970 eruption of Hekla volcano.
Recent Brachiopod-Coralline Sponge Communities and Their Paleoecological Significance
Authors: Jackson Jeremy B. C. , Goreau Thomas F. , Hartman Willard D.
Published: October 2006

Brachiopods and coralline sponges are the dominant taxa of a series of parallel pantropical communities found in cryptic habitats of Recent coral reefs, where these organisms may cover almost the entire available surface area. It is suggested that the continued survival and success of these and other groups of considerable paleontological importance resulted from their occupation of cryptic reef habitats after competition with more rapidly growing hermatypic corals in the Middle Jurassic when scleractinian reefs first appeared.
Insect Photoreceptor: An Internal Ocellus Is Present in Sphinx Moths
Authors: Eaton John L.
Published: October 2006

Adult sphinx moths lack external ocelli. In
Manduca sexta
and other anocellate moths structures homologous to ocelli have been observed. Histological examination of such a structure in Manduca sexta has shown structural similarities to ocelli of other insects. Electrophysiological studies revealed a response to light stimuli similar to the electroretinogram of external ocelli. The evidence strongly suggests that the structures are internal ocelli.
Pineal
N
-Acetyltransferase Activity: Effect of Sympathetic Stimulation
Authors: Volkman Paul H. , Heller Alfred
Published: October 2006

Stimulation of preganglionic sympathetic fibers to the superior cervical ganglia elevates the activity of pineal
N
-acetyltransferase. After the stimulation-induced rise in enzyme activity, a return toward baseline levels occurs whether or not nerve stimulation is continued. The ability of pineal
N
-acetyltransferase activity to fall in the presence of stimulation may account for the persistence of its rhythm in blinded animals.
Fate of Air Pollutants: Removal of Ethylene, Sulfur Dioxide, and Nitrogen Dioxide by Soil
Authors: Abeles F. B. , Craker L. E. , Forrence L. E. , Leather G. R.
Published: October 2006

The ultimate sink for many air pollutants is unknown. Data are presented here in support of the idea that reaction with soil, through microbial or chemical means, can remove ethylene, other hydrocarbons, sulfur dioxide, and nitrogen dioxide from the air.
Eye Marks in Vertebrates: Aids to Vision
Authors: Ficken Robert W. , Matthiae Paul E. , Horwich Robert
Published: October 2006

Lines leading forward from the eye may function as aiming sights in many small vertebrates. The chief evidence is the correlation of distribution and positions of eye-lines in various vertebrate groups with predatory feeding habits. Dark patches around the eye may serve to reduce glare in species in bright environments. Facial patterns often have multiple functions.
Sporozoite-Induced Infections of
Plasmodium berghei
Administered by the Oral Route
Authors: Yoeli Meir , Most Harry
Published: October 2006

Administration of suspensions of
Plasmodium berghei
sporozoites by the oral route to groups of susceptible animals (A/J mice, young rats, hamsters, and
Thamnomys
) resulted in high rates of infection (66 to 100 percent). Control animals each given a suspension of 200,000 to 500,000 erythrocytes infected with
P. berghei
by the same oral route did not develop parasitemia. Direct intubation of sporozoite suspensions into the stomach failed to produce parasitemia. In vitro studies showed that sporozoites kept in medium M 199 acidified to pH 3.6 (the acid environment of the rat stomach) for 5 to 15 minutes lost their viability and infectivity. We believe that sporozoites of
P. berghei
find their way to the bloodstream during their brief sojourn in the esophagus.
Mineral Element Correlation with Adenohypophyseal-Adrenal Cortex Function and Stress
Authors: Flynn Arthur , Pories Walter J. , Strain William H. , Hill Orville A.
Published: October 2006

A statistical correlation was made between adrenocorticotropin (ACTH) and four elements in rats under control, stress, and stress-recovery conditions. Blood serum zinc showed a strong positive correlation with the rise in ACTH during stress and its decline in stress recovery. Serum calcium, copper, and magnesium demonstrated little correlation with ACTH changes. The strong ACTH-zinc correlation points to an as yet undefined interaction between ACTH and zinc.
Submarine Canyon Erosion: Contribution of Marine Rock Burrowers
Authors: Warme John E. , Scanland Thomas B. , Marshall Neil F.
Published: October 2006

Rocks of the rim and upper walls of Scripps Submarine Canyon are intensely burrowed by marine invertebrates. Important excavators are bivalves, polychaetes, and sipunculoids whose activities culminate in a network of passageways and eventual disintegration of the rocks. In many localities erosion by animals is more important than erosion by physical and chemical processes.
Selective Recovery from Retrograde Amnesia Produced by Hippocampal Spreading Depression
Authors: Kapp Bruce S. , Schneider Allen M.
Published: October 2006

Injections of potassium chloride into the hippocampus after learning produce temporary disruption of neural activity and retrograde amnesia. Recovery from the amnesia is selective—rats recover from amnesia of events that occurred 24 hours before injection but do not recover from amnesia of events that occurred 10 seconds before injection.
Metachronal Limb Movements by
Artemia salina
: Synchrony of Male and Female during Coupling
Authors: Lent Charles M.
Published: October 2006

Studies of the metachronal rhythms of
Artemia salina
reveal that limb movements of the male and female are synchronous during precopulatory coupling. Synchrony is an adaptation which maintains efficiency in locomotion, respiration, and feeding. The male acts as the pacemaker for the pair and drives the female at a higher rate than she exhibits when alone.
Cyclic Adenosine Monophosphate: Function in Photoreceptors
Authors: Miller W. H. , Gorman R. E. , Bitensky M. W.
Published: October 2006

Inactivation of adenylate cyclase in outer segments of retinal photoreceptor cells is proportional to the bleaching of rhodopsin. Membranes of the outer segments also contain a particulate, light-insensitive phosphodiesterase of high specific activity. In electrophysiological experiments, application of cyclic adenosine monophosphate along with a methylxanthine mimics the effects of illumination on the photoreceptor cell of the compound eye of
Limulus
.
Silkworm
Bombyx mori
L.: Nature of Diapause Factor
Authors: Sonobe Haruyuki , Ohnishi Eiji
Published: October 2006

The diapause factor which is responsible for the induction of embryonic diapause in the silkworm (
Bombyx mori
L.) was isolated from the heads of female moths. It was extracted with 80 percent ethanol or 80 percent methanol and was heat-stable and not dialyzable. Since the active material was precipitated with ammonium sulfate and lost when incubated with proteolytic enzymes, it is highly probable that the diapause factor is a protein or a complex molecule containing peptide bonds. Molecular sieve techniques revealed two species of the diapause factor. The molecular weight of the smaller species lies between 5,000 and 10,000.
Simultaneous Detection of Reverse Transcriptase and High Molecular Weight RNA Unique to Oncogenic RNA Viruses
Authors: Schlom J. , Spiegelman S.
Published: October 2006

The simultaneous assay of the reverse transcriptase and 60
S
to 70
S
RNA of oncogenic RNA viruses is described. The virus can be detected at low concentrations in biological fluids containing enzymatically active cell fragments or other contaminants. The fact that two features diagnostic of the oncornaviruses are used in the tests increases the certainty with which a positive outcome can be interpreted.
Jupiter: An Unidentified Feature in the 5-Micron Spectrum of the North Equatorial Belt
Authors: Münch G. , Neugebauer G.
Published: October 2006

Grating spectra of the North Equatorial Belt of Jupiter between 4.5 and 5.1 microns, obtained with a nominal resolving power of 180, are presented. An absorption feature centered at 4.73 microns and not due to a known constituent has been found. Its possible identification is discussed.
Genetic Polymorphisms in Varied Environments
Authors: Powell Jeffrey R.
Published: October 2006

Thirteen experimental populations of
Drosophila willistoni
were maintained in cages, in some of which the environments were relatively constant and in others varied. After 45 weeks, the populations were assayed by gel electrophoresis for polymorphisms at 22 protein loci. The average heterozygosity per individual and the average number of alleles per locus were higher in populations maintained in heterogeneous environments than in populations in more constant environments.
Fragmentation of Nitrogen-14 Nuclei at 2.1 Gev per Nucleon
Authors: Heckman Harry H. , Greiner Douglas E. , Lindstrom Peter J. , Bisser Frederick S.
Published: October 2006

An experiment has been carried out at the bevatron on the nuclear fragmentation of nitrogen-14 ions at an energy of 2.1 billion electron volts (Gev) per nucleon. Because of the near equality of the velocities of the nitrogen-14 beam and the fragmentation products at an angle of 0°, we find it possible to identify the nuclear fragments isotopically.
Human Leukemic Cells: In vitro Growth of Colonies Containing the Philadelphia (Ph
1
) Chromosome
Authors: Chervenick Paul A. , Ellis Lawrence D. , Pan Sylvia F. , Lawson Alton L.
Published: October 2006

Human leukemic cells with a marker (Philadelphia; Ph
1
) chromosome gave rise to granulocytic and mononuclear cell colonies when grown in vitro. All metaphases from a single colony were either Ph
1
positive or Ph
1
negative. No colonies contained a mixed cell population. This suggests that leukemic and normal cells exist simultaneously and that in vitro colonies are clonal in origin.
Snake Neurotoxins: Effect of Disulfide Reduction on Interaction with Electroplax
Authors: Bartels Eva , Rosenberry Terrone L.
Published: October 2006

Reduction of disulfide bonds of cobra neurotoxin by dithiothreitol results in decreased activity on the electroplax preparation. Activity is restored completely after reoxidation by 3,3′-dithiobis[6-nitrobenzoic acid]. Reduction of the disulfide bonds in the vicinity of the receptor does not decrease the effect of cobrotoxin.
Isolation of Filaments from Brain
Authors: Shelanski Michael L. , Albert Stewart , DeVries George H. , Norton William T.
Published: October 2006

A method is presented for the isolation of filaments of 90-angstrom diameter from the white matter of bovine brain by first floating the myelinated axons in a centrifugal field and then fractionating the axons on a series of density gradients. This results in a fraction that contains two types of bundles of filaments but few other constituents. The filaments are stable over a wide range of temperatures and at both low and high ionic strength. Their density and their resistance to digestion by ribonuclease and deoxyribonuclease indicate that they are primarily protein. The molecular weight of the subunit is approximately 60,000. The protein does not comigrate with microtubule protein and does not bind cholcicine or nucleotides.
Photic Responses in Hyperkinesis of Childhood
Authors: Shetty Taranath
Published: October 2006

Intravenous injections of drugs that stimulate the central nervous system decreased photic driving responses and photomyoclonic responses in hyperkinetic children. Neither injections of saline in these children nor injections of stimulant drugs in normal subjects produced such diminution. The neurophysiological implications are discussed.
Iron-Rich Basal Sediments from the Eastern Equatorial Pacific: Leg 16, Deep Sea Drilling Project
Authors: Cronan D. S. , van Andel T. H. , Heath G. Ross , Dinkelman M. G. , Bennett R. H. , Bukry David , Charleston Santiago , Kaneps Ansis , Rodolfo K. S. , Yeats R. S.
Published: October 2006

Iron-rich sediments chemically similar to those forming at present on the crest of the East Pacific Rise have been found just above basement at widely separated drill sites in the eastern equatorial Pacific, including three sites of Leg 16 of the Deep Sea Drilling Project. These sediments were probably formed when the basement was at the crest of this rise and have moved to their present location as a result of sea-floor spreading.
Circadian Rhythm in Uptake of Tritiated Thymidine by Kidney, Parotid, and Duodenum of Isoproterenol-Treated Mice
Authors: Burns E. Robert , Scheving Lawrence E. , Tsai Tien-Hu
Published: October 2006

The total uptake of [
3
H]thymidine by the mouse parotid gland, kidney, and duodenum exhibits a circadian rhythm. A single injection of isoproterenol changes the phasing and amplitude of these rhythms. Depending on the organ, there are certain points in the circadian time structure when isoproterenol stimulates or inhibits the uptake of thymidine; at other time points there is no difference between the responses to isoproterenol and to saline.
Mariner 9 Celestial Mechanics Experiment: Gravity Field and Pole Direction of Mars
Authors: Lorell J. , Born G. H. , Christensen E. J. , Jordan J. F. , Laing P. A. , Martin W. L. , Sjogren W. L. , Shapiro I. I. , Reasenberg R. D. , Slater G. L.
Published: October 2006

Analysis of the Mariner 9 radio-tracking data shows that the Martian gravity field is rougher than that of Earth or the moon, and that the accepted direction of Mars's rotation axis is in error by about 0.5°. The new value for the pole direction for the epoch 1971.9, referred to the mean equatorial system of 1950.0, is right ascension α = 317.3° ± 0.3°, declination δ = 52.6° ± 0.2°. The values found for the coefficients of the low-order harmonics of Mars's gravity field are as follows:
J
2
=(1.96±0.01) × 10
-3
, referred to an equatorial radius of 3394 kilometers;
C
22
= -(5 ± 1) × 10
-5
; and
S
22
= (3 ± 1) × 10
-5
. The value for
J
2
is in excellent agreement with the result from Wilkins' analysis of the observations of Phobos. The other two coefficients imply a value of (2.5 ± 0.5) × 10
-4
for the fractional difference in the principal equatorial moments of inertia; the axis of the minimum moment passes near 105°W.
Mammary Carcinoma: A Specific Biochemical Defect in Autonomous Tumors
Authors: McGuire W. L. , Huff K. , Jennings A. , Chamness G. C.
Published: October 2006

Rat mammary carcinoma (R3230AC) which does not regress after ovariectomy has a markedly reduced amount of cytoplasmic estradiol binding protein. Cytoplasm from the tumor fails to interact with estradiol sufficiently to permit estradiol binding to tumor chromatin. This defect can be corrected in vitro by substituting cytoplasm, containing the binding protein, from rat uterus, thus permitting estradiol binding to tumor chromatin. The results indicate that the hormonal autonomy of this carcinoma is due to a lack of estradiol binding protein and not to the inability of estradiol to interact with the cell genome.
Population Modeling: A Systems Approach
Authors: Coulman G. A. , Reice S. R. , Tummala R. L.
Published: October 2006

A single species population dynamics model based on the functional representations of birth, growth, and death has been constructed. Laboratory parameter estimates were used in a computer implementation of the model to simulate field populations. Preliminary results of replicate runs with parametric sampling indicated reasonable statistical agreement. Further development with the systems analysis technique is planned.
Presence of Lateral Eye Lens Crystallins in the Median Eye of the American Chameleon
Authors: McDevitt David S.
Published: October 2006

With the use of immunofluorescence techniques, gamma globulin antibody specific for the crystallins of
Anolis carolinensis
lateral eye lens was applied to sections through the median (parapineal) eye of
Anolis carolinensis
. Only the median eye lens exhibited fluorescence specific for the crystallins; other structures were negative. These results indicate that the lens of the reptilean median eye shares tissue-specific antigenic determinants with the lens of the lateral eye. This suggests a possible evolutionary relation between the two structures, based on biochemical, as well as previously reported anatomical, criteria.
Auditory Evoked Response: Meaningfulness of Stimuli and Interhemispheric Asymmetry
Authors: Matsumiya Y. , Tagliasco V. , Lombroso C. T. , Goodglass H.
Published: October 2006

Interhemispheric asymmetries of different magnitudes were observed in human cortical auditory evoked responses to speech and sound-effect stimuli. The wave with peak asymmetry occurred 100 milliseconds after signal onset. The amount of asymmetry of the amplitude of this wave was related to the meaningfulness to the subject of the auditory stimulus rather than to the mere use of verbal versus nonverbal materials.
Turnover of Molecules Which Maintain the Normal Surfaces of Contact-Inhibited Cells
Authors: Baker Joffre B. , Humphreys Tom
Published: October 2006

In confluent cultures normal chick embryo fibroblasts become highly agglutinable by concanavalin A within 6 hours after their synthesis of protein is inhibited by cycloheximide, pactamycin, or emetine. When growing cells are similarly treated, they fail to become more agglutinable. Apparently, molecules which maintain the normal structure of the cell surface must be replaced continually when cell growth is contact inhibited.
Δ
9
-Tetrahydrocannabinol: Aversive Effects in Rat at High Doses
Authors: Elsmore Timothy F. , Fletcher Gordon V.
Published: October 2006

Water-deprived rats were administered a single dose of Δ
9
-tetrahydrocannabinol either orally or intraperitoneally immediately after their first taste of a saccharine solution. In tests beginning 47 hours after drug administration, a dose-related reversal of rats' normal preference for saccharine was found. The data suggest that the drug produces aversive effects at doses of 1 to 32 milligrams per kilogram.
Human Phosphoglycerate Kinase and Inactivation of the X Chromosome
Authors: Deys B. F. , Grzeschick K. H. , Grzeschick A. , Jaffé E. R. , Siniscalco M.
Published: October 2006

The fibroblasts derived from the skin of a woman heterozygous for an X-linked deficiency of phosphoglycerate kinase represented a mosaic. Two of 22 clones with normal glucose-6-phosphate dehydrogenase activity and hypoxanthine(guanine) phosphoribosyltransferase activity had no phosphoglycerate kinase activity detected by electrophoresis. Because the loci for glucose-6-phosphate dehydrogenase and hypoxanthine(guanine)phosphoribosyltransferase are already known to undergo inactivation and to be on the short arm of the X chromosome and the locus for phosphoglycerate kinase is on the long arm, these observations support the conclusion that the entire human X chromosome can be involved in X inactivation.
Uricotelism and Low Evaporative Water Loss in a South American Frog
Authors: Shoemaker Vaughn H. , Balding David , Ruibal Rodolfo , McClanahan Lon L.
Published: October 2006

A South American anuran (
Phyllomedusa sauvagii
) produced large amounts of semisolid urate when it was maintained on a diet of insects. Rates of evaporative water loss in
Phyllomedusa sauvagii
were only about 5 to 10 percent of those other anurans tested and were similar to those of lizards of comparable size.
An Eocene Hystricognathous Rodent from Texas: Its Significance in Interpretations of Continental Drift
Authors: Wood Albert E.
Published: October 2006

The earliest known representative of the fundamentally South American and African hystricognathous rodents has recently been found in the middle or late Eocene of southwestern Texas; this discovery supports the postulate of a northern and independent origin for the two southern groups and increases the evidence against mid-Tertiary trans-Atlantic migration of these rodents at a time when the South Atlantic was narrower than it is at present. The fossil seems to be related to the North American Eocene family Sciuravidae.
Behaviorally Evoked Hippocampal Theta Waves: a Cholinergic Response
Authors: Teitelbaum Herman , Lee Jack F. , Johannessen Jan N.
Published: October 2006

Forced running in a treadmill results in the instantaneous appearance of a synchronous electroencephalographic pattern in the dorsal hippocampus of the rat. A similar bioelectric response in the absence of movement is induced by physostigmine. Both responses are blocked with scopolamine. Lesions of the medial septal nucleus abolish hippocampal theta waves induced by forced running or physostigmine.
Leaf Infections: Siderochromes (Natural Polyhydroxamates) Mimic the "Green Island" Effect
Authors: Atkin C. L. , Neilands J. B.
Published: October 2006

Topical application of as little as 5 × 10
-12
moles of pure siderochromes (polyhydroxamate iron-transport compounds from bacteria and fungi) onto detached bean leaves causes spots of chlorophyll retention that are surrounded by chlorotic halos. These spots appear similar to "green islands" that are caused by certain fungal infections on leaves and are somewhat similar to zones where senescence is delayed by cytokinin.
Isolation and Characterization of Two Major Urinary Metabolites of Δ
1
-Tetrahydrocannabinol
Authors: Burstein Sumner , Rosenfeld Jack , Wittstruck Thomas
Published: October 2006

Two of the major metabolites which appear in rabbit urine after the administration of Δ
1
-tetrahydrocannabinol have been isolated and their structures have been tentatively established. The available evidence indicates that they are 7-carboxy-Δ
1
-tetrahydrocannabinols with an additional hydroxyl group on the side chain. The substances occur both free and as conjugates.
Information-Processing by Pigeons
Authors: Maki William S. , Leuin Terry C.
Published: October 2006

Two pigeons matched to sample on the basis of color or line orientation when a sample consisted of a value for each stimulus dimension or a value for only one dimension. When the duration of the sample stimulus was varied to maintain constant performance, compound stimuli required more time than single elements.