bluuebunny/crossref_metadata_2025 huggingface dataset:
Mars: Occurrence of Liquid Water
Authors: Ingersoll Andrew P.
Published: October 2006

In the absence of juvenile liquid water, condensation of water vapor to ice and subsequent melting of ice are the only means of producing liquid water on the martian surface. However, the evaporation rate is so high that the available heat sources cannot melt pure ice. Liquid water is therefore limited to concentrated solutions of strongly deliquescent salts.
Cross-Reactions between Streptococcal M Proteins and Human Transplantation Antigens
Authors: Hirata Arthur A. , Terasaki Paul I.
Published: October 2006

Allogeneic antiserums against human lymphocytes were specifically inhibited by M protein from beta hemolytic group A
Streptococcus pyogenes
, type 1. Analogous M proteins from streptococcus types 3, 4, 5, 6, 12, and 14 had little or no inhibitory activity. The specific inhibition by M protein is not a result of anticomplementary activity or of coating of the lymphocyte surface. Streptococcal polysaccharide and 73 other polysaccharides were inactive. Because all seven HL-A specificities tested were inhibited, it is inferred that M1 protein has a structure common to human histocompatibility antigens.
Sarcocystis
: Development in Cultured Avian and Mammalian Cells
Authors: Fayer Ronald
Published: October 2006

Sarcocystis
, a protozoan that parasitizes muscle tissue of reptiles, birds, and mammals, including man, developed in avian and mammalian cell cultures. Motile banana-shaped organisms, released from cysts in grackle muscle, entered cells and transformed into enlarged ellipsoid or oblong stages, which developed into either multinucleate or cyst-like stages, or both.
Alcohol Aversion in the Rat: Behavioral Assessment of Noxious Drug Effects
Authors: Nachman Marvin , Lester David , Le Magnen Jacques
Published: October 2006

Injections of
p
-chlorophenylalanine or
n
-butyraldoxime given after rats were first given a 10-minute drinking test with saccharin or ethanol solutions produced a learned aversion to these solutions. These findings suggest that the reduced self-selection of alcohol (preference) resulting from the administration of these drugs, reported by others, is not specifically alcohol-related. The technique described offers a sensitive procedure for the assessment of unpleasant effects of drugs.
Scheie and Hurler Syndromes: Apparent Identity of the Biochemical Defect
Authors: Wiesmann Ulrich , Neufeld Elizabeth F.
Published: October 2006

Fibroblasts cultured from the skin of Scheie and Hurler patients are deficient in the same specific factor required for normal mucopolysaccharide metabolism.
Bronchograms and Tracheograms of Seals under Pressure
Authors: Kooyman G. L. , Hammond D. D. , Schroeder J. P.
Published: October 2006

Radiograms of the upper portion of the respiratory system were obtained at pressures up to 31.6 atmospheres absolute in the Weddell seal,
Leptonychotes weddelli
, and the northern elephant seal,
Mirounga angustirostris
. The trachea was considerably compressed but not fully collapsed at the highest pressures. No measurable change in the size of the bronchioles and smaller bronchi was observed. Measurements of total lung volume obtained simultaneously showed that the seals consistently dived with a small volume.
Hemoglobin Interaction: Modification of Solid Phase Composition in the Sickling Phenomenon
Authors: Bertles John F. , Rabinowitz Rosanne , Döbler Johanna
Published: October 2006

Direct analyses of solid phase formed by deoxygenating solutions of sickle-cell hemoglobin (Hb S) in the presence of certain other hemoglobin species show that hemoglobins A and C can participate in the filamentous fine structure characteristic of the sickling phenomenon. In contrast, fetal hemoglobin (Hb F) is nearly completely excluded.
Birth Control after 1984
Authors: Djerassi Carl
Published: October 2006

1) Eric Blair (alias George Orwell) can rest easy in his grave, because birth control by governmentally imposed methods, such as incorporation of a contraceptive agent into drinking water, is totally unfeasible by 1984.

2) Fundamentally new birth control procedures in the female (for example, a once-a-month luteolytic or abortifacient agent) and a male contraceptive pill probably will not be developed until the 1980's at the earliest, and then only if major steps of the type outlined in this article are instituted in the early 1970's. Development during the next decade of practical new methods of birth control without important incentives for continued active participation by the pharmaceutical industry is highly unlikely. If none are developed, birth control in 1984 will not differ significantly from that of today.
Expression of Gene
rrg
Is Associated with Reversion of NIH 3Tt3 Transformed by LTR-c-H-
ras
Authors: Contente Sara , Kenyon Kaylene , Rimoldi Donata , Friedman Robert M.
Published: October 2006

A partial complementary DNA was isolated for a gene (
rrg
) that is normally expressed in mouse NIH 3T3 cells, but is down-regulated after cellular transformation by long terminal repeat (LTR)-activated c-H-
ras
(LTR-c-H-
ras
). This gene was reexpressed in a nontumorigenic persistent revertant cell line created by prolonged treatment of the transformed cells with mouse interferon α/β. Persistent revertants stably transfected with
rrg
complementary DNA antisense expression vectors appeared transformed, had decreased amounts of
rrg
messenger RNA, and were tumorigenic in nude mice. Stable transfection with sense constructs did not alter the normal morphology, message level, or nontumorigenicity of the persistent revertant cell line.
Adhesion of Human B Cells to Germinal Centers in Vitro Involves VLA-4 and INCAM-110
Authors: Freedman Arnold S. , Munro J. Michael , Rice G. Edgar , Bevilacqua Michael P. , Morimoto Chikao , McIntyre Bradley W. , Rhynhart Kurt , Pober Jordan S. , Nadler Lee M.
Published: October 2006

Human B lymphocytes localize and differentiate within the microenvironment of lymphoid germinal centers. A frozen section binding assay was developed for the identification of those molecules involved in the adhesive interactions between B cells and lymphoid follicles. Activated human B cells and B cell lines were found to selectively adhere to germinal centers. The VLA-4 molecule on the lymphocyte and the adhesion molecule INCAM-110, expressed on follicular dendritic cells, supported this interaction. This cellular interaction model can be used for the study of how B cells differentiate.
Cyclic Adenosine Monophosphate and Norepinephrine: Effects on Transmembrane Properties of Cerebellar Purkinje Cells
Authors: Siggins G. R. , Oliver A. P. , Hoffer B. J. , Bloom F. E.
Published: October 2006

Electrical properties of Purkinje cells were recorded by intracellular microelectrode during extracellular electrophoretic application of gamma aminobutyrate, norepinephrine, cyclic adenosine monophosphate, and dibutyryl cyclic adenosine monophosphate. All these substances hyperpolarized Purkinje cells. Transmembrane resistance decreased during gamma aminobutyrate hyperpolarization. In contrast, norepinephrine and the cyclic nucleotides generally elevated resistance. These results show that cyclic nucleotides mimic the unique effects of norepinephrine on the bioelectric properties of neuronal membranes.
Lesch-Nyhan Syndrome: Altered Kinetic Properties of Mutant Enzyme
Authors: McDonald John A. , Kelley William N.
Published: October 2006

Hypoxanthine-guanine phosphoribosyltransferase is virtually inactive in erythrocytes from patients with the classical Lesch-Nyhan syndrome. In one such patient, activity of this enzyme ranged from 8 to 34 percent of normal in erythrocytes when assayed with a very high concentration of magnesium 5-phosphoribosyl-1-pyrophosphate. In addition, the mutant enzyme exhibited sigmoidal kinetics with this substrate as well as an increased Michaelis constant for both guanine and hypoxanthine. These findings provide the first evidence for genetic heterogeneity within the group of patients with the Lesch-Nyhan syndrome.
Receptive Field Mechanism in the Vertebrate Retina
Authors: Naka Ken-Ichi
Published: October 2006

In the catfish retina there are two types of ganglion cells: in one type (type A cell) a spot of light at the center of its receptive field gives rise to a sustained discharge whereas an annulus gives rise to a transient response, and in the other type (type B cell) the response pattern is reversed for a spot and an annulus. Current injected into the horizontal cell induces spike discharges of the ganglion cell very similar to that elicited by a spot of light or by an annulus. In both types of receptive fields, depolarization of the horizontal cell gives rise to a response of the ganglion cell similar to that elicited by a spot of light, whereas hyperpolarization of the cell gives rise to a response of the ganglion cell similar to that elicited by an annulus. Current through a single injecting electrode could drive two types of cells simultaneously. Interaction between a spot of light and an annulus can also be simulated by replacing one light stimulus by current of the proper polarization injected into the horizontal cells. Results suggest that interactions among three neuronal structures, the receptor, the horizontal cell, and the bipolar cell, produce the basic receptive field organization in the channel catfish.
Telemetered Recording of Hormone Effects on Hippocampal Neurons
Authors: Pfaff Donald W. , Silva M. Teresa A. , Weiss Jay M.
Published: October 2006

Frequency-modulated telemetry was used to record the effects of hormones on single-unit activity in the brains of freely moving rats. Corticosterone decreased unit activity in the dorsal hippocampus. Adrenocorticotrophic hormone had the opposite effect.
Cholinergic Sensitivity: Normal Variability as a Function of Stimulus Background
Authors: Bito Laszlo Z. , Dawson M. Joan , Petrinovic Ljerka
Published: October 2006

The sensitivity of the normally innervated iris sphincter to its neurotransmitter, acetylcholine, and to related agents varies inversely with the preexisting physiological stimulus background, that is, the environmental light intensity. This normal variability suggests the existence of a negative feedback mechanism whereby sensitivity of the effector cell is modulated by a product of neuronal activity.
DNA Synthesis and Interaction between Controlled Feeding Schedules and Partial Hepatectomy in Rats
Authors: Barbiroli Bruno , Potter Van R.
Published: October 2006

The rate of DNA synthesis has been measured during liver regeneration in rats adapted to a controlled feeding schedule. The results show two different phenomena in the regulation of DNA synthesis. The first is the appearance of a peak of DNA synthesis following the operation itself and independent of the time of the day; the second one is the presence of constant diurnal variations in the rate of DNA synthesis in response to the partial hepatectomy and following the stimulus or stimuli of the controlled feeding schedule.
Susceptibility of Mink to Sheep Scrapie
Authors: Hanson Robert P. , Eckroade Robert J. , Marsh Richard F. , Zu Rhein Gabriele M. , Kanitz Charles L. , Gustafson Donald P.
Published: October 2006

A progressive, fatal spongiform polioencephalopathy was induced in mink intracerebrally inoculated with a suspension of brain from a Suffolk sheep with naturally acquired scrapie. The clinical signs and pathological lesions of the experimental disease were indistinguishable from transmissible mink encephalopathy, a disease of undetermined origin that occurs in mink.
Uric Acid Dihydrate in Bird Urine
Authors: Lonsdale Kathleen , Sutor D. June
Published: October 2006

X-ray diffraction analysis shows that the white excrement from a budgerigar consists mainly of uric acid dihydrate. Initially this material is in the form of a smectic (or cholesteric) phase, which transforms to the normal crystalline phase either on aging or on removal of the minor (soluble) constituents of the excrement with water or dilute acids.
Phospholipid—Calcium Phosphate Complex: Enhanced Calcium Migration in the Presence of Phosphate
Authors: Cotmore John M. , Nichols George , Wuthier Roy E.
Published: October 2006

In the presence of acidic phospholipids, inorganic phosphate greatly enhances the net migration of calcium ions from the aqueous phase to the organic phase, an effect that does not occur at less than the physiological
p
H. The calcium complex in the organic phase is shown by electron microscopy to consist of spherules, composed of stoichiometric amounts of calcium, inorganic phosphate, and phospholipid. The demonstration of complex formation between calcium phosphate and acidic phospholipids adds support to the concept that phospholipids are involved in biological mineralization.
Phosphatidylserine: Selective Enhancer of Histamine Release
Authors: Goth Andres , Adams H. Ray , Knoohuizen Mary
Published: October 2006

Phosphatidylserine, in contrast with other phospholipids, markedly enhanced histamine release from rat peritoneal mast cells induced by dextran or protein antigens. This enhancing effect was selective for dextran and protein antigens and did not extend to the action of compound 48/80 or chymotrypsin. These findings suggest a role for phosphatidylserine in the response of mast cells to antigens.
Antiprismatic Coordination about Xenon: The Structure of Nitrosonium Octafluoroxenate(VI)
Authors: Peterson S. W. , Holloway J. H. , Coyle B. A. , Williams J. M.
Published: October 2006

The structure of nitrosonium octafluoroxenate(VI), 2NOF ⋅ XeF
6
, has been determined by means of single-crystal x-ray counter methods (
R
-index = 0.046, weighted
R
-index = 0.042). The space group is
Pnma
, with
a
= 8.914(10) angstroms,
b
= 5.945(10) angstroms, and
c
= 12.83(2) angstroms (the numbers in parentheses are the standard deviations to the least significant digit or digits); the calculated density (ρ) is 3.354 grams per cubic centimeter, and there are four formula units per unit cell. The material consists of well-separated NO
+
and (XeF
8
)
2-
ions; the structural formula is thus (NO)
2
(XeF
8
). The anion configuration is that of a slightly distorted Archimedean antiprism. The observed distortion appears incompatible with a lone-pair repulsion model. Xenon-fluorine bond lengths of 1.971(7), 1.946(5), 1.958(7), 2.052(5), and 2.099(5) angstroms were found.
Ion Binding by Synthetic Macrocyclic Compounds
Authors: Christensen J. J. , Hill J. O. , Izatt R. M.
Published: October 2006

The existence of synthetic macrocyclic molecules with hydrophilic cavities containing multiple binding atoms and with hydrophobic exteriors gives rise to extraordinary possibilities with respect to the design and synthesis of molecules with specific cation and anion binding properties. The preparation of many new macrocyclic compounds has recently been reported, but few practical applications for them have been suggested. From the information available, it is becoming clear that it should be possible to synthesize macrocycles that will have specified, or selected, ion binding properties. Cavity size can be varied to accommodate only those cations or anions within a specified narrow band of sizes. Numbers and types of coordinating atoms can be chosen to give essentially electrostatic or covalent bonding or a combination of the two in a metalmacrocycle complex. The metal ligand bond appears to be predominantly ionic in the case of the cyclic polyethers but the covalent character increases on substitution of sulfur or nitrogen for oxygen donor atoms. The essential hydrophobic exteriors of the macrocycles can be modified by the addition of side chains and groups to facilitate the solution of anions and cations in organic solvents. The structures of many macrocycles can be made to approximate naturally occurring molecules, that is, cyclic polyethers similar to macrocyclic antibiotics of the valinomycin and nonactin types and cyclic polyamines similar to porphyrins. Macrocycles are also useful as model compounds for the study of metal interactions with biological systems. The synthetic macrocycles thus represent an intriguing new area of coordination chemistry, the systematic study of which should lead to many interesting and useful chemical applications in the field of metal complexation in solution.
Gametogony of
Sarcocystis
sp. in Cell Culture
Authors: Fayer Ronald
Published: October 2006

Sexual stages and cystlike bodies of
Sarcocystis
sp., a protozoan parasite found in muscles of reptiles, birds, and mammals, including man, developed in cell culture. Motile organisms, obtained from leg muscles of wild grackles, were inoculated into cell line cultures of embryonic bovine kidney. Mature micro- and macrogametes and the cystlike forms were found 30 and 42 hours after inoculation, respectively. These observations indicate that the parasite is probably a coccidium.
Diurnal Rhythm in Endoplasmic Reticulum of Rat Liver: Electron Microscopic Study
Authors: Chedid A. , Nair V.
Published: October 2006

Electron microscopy of rat hepatocytes revealed a diurnal variation in the relative amounts of endoplasmic reticulum structures and regional differences in their distribution within the hepatic lobule. The diurnal changes in smooth and rough endoplasmic reticulum structures were compared with the diurnal changes in the hepatic microsomal enzyme hexobarbital oxidase. In the control group, at the time when enzyme activity was maximum, the amount of smooth endoplasmic reticulum was also maximum and vice versa. When the enzyme rhythm was abolished, as in blinded rats, the diurnal rhythm in the endoplasmic reticulum was also abolished.
"Non-Concept" of "No-Threshold": Chemicals in the Environment
Authors: Dinman Bertram D.
Published: October 2006

Present confusion that equates the presence of a biological effect with a deleterious implication ignores several concepts. To believe that a single molecule's presence in a cell implies a definite potential for deleterious effect disregards stochastic considerations. To believe that such molecules cause an undesirable effect disregards the presence of multiplicity of interfering substances. Such thinking also does not take into account the fact that the dose of a foreign atom may be related to the probability of its interacting with an available active site, or that similar probability governs the answers to the question of whether interactions will occur at discrete topographical loci upon a structural or functional molecule (or on a possible precursor). While the construction of stochastically sound model is remote, the reasonableness of the hierarchy of cellular element concentrations as these relate to metabolic function suggests that a threshold for biological activity exists within a cell at 10
4
atoms.

The cellular organism operates within a quantitative rate limit that transcends any statements having only qualitative bases. Thus concepts concerning encroachments on response capabilities over a lifespan are inadequate descriptors of biological activity in the absence of quantitative qualifiers.
Uranium in Runoff from the Gulf of Mexico Distributive Province: Anomalous Concentrations
Authors: Spalding Roy F. , Sackett William M.
Published: October 2006

Uranium concentrations in North American rivers are higher than those reported 20 years ago. The increase is attributed to applications to agricultural land of larger amounts of phosphate fertilizer containing appreciable concentrations of uranium. Experiments showing a constant phosphorous-uranium ratio for various types of fertilizers and for the easily solubilized fraction of 0-46-0 fertilizers support this view.
Cell Aggregation: Role of Acid Mucopolysaccharides
Authors: Pessac Bernard , Defendi Vittorio
Published: October 2006

Factors that induce cell aggregation are released by several types of chick embryo and mammalian cell cultures. These aggregation factors are also present in some serums. The factors in each of the preparations tested were inactivated by treatment with bovine testicular hyaluronidase. Conversely, hyaluronic acid promoted aggregation of only those cells that were aggregated by media containing the factors. These factors appear to be acid mucopolysaccharides, with hyaluronic acid being a major component.
Rat Brain Binds Adrenal Steroid Hormone: Radioautography of Hippocampus with Corticosterone
Authors: Gerlach John L. , McEwen Bruce S.
Published: October 2006

Tritiated corticosterone injected subcutaneously into adrenalectomized male rats 1 hour before killing produced intense labeling of the hippocampus in radioautograms prepared by a method that reduced or prevented diffusion of the radioactive material. The pyramidal neurons of the cornu ammonis and the granule neurons of the gyrus dentatus contained more radioactivity than did other regions of the brain; however, the intensity of labeling varied among adjacent neurons. The nuclei of many neurons were clearly labeled but radioactivity was relatively sparse in the cytoplasm, in the axons where they branch from cell bodies, and in adjacent neuropil.
Magnetite: Behavior near the Single-Domain Threshold
Authors: Dunlop D. J.
Published: October 2006

Maximum values for the single-domain threshold
d
0
and superparamagnetic threshold d
8
in pure magnetite are found to be 570 ± 50 and 350 ± 50 angstroms, respectively. Particles larger than
d
0
but smaller than about 0.25 micron have size-dependent saturation remanences and coercive forces like those of multidomain particles, but intense and stable thermoremanent magnetization like that of single-domain particles. The presence of magnetite grains in this size range could account for the essentially single-domain character of stable natural remanence in many volcanic and intrusive rocks.
Angiotensin I: Metabolism by Plasma Membrane of Lung
Authors: Ryan J. W. , Smith Una , Niemeyer R. S.
Published: October 2006

(8-L-[
14
C] phenylalanine) angiotensin I is metabolized in one passage through blood-free lungs. Approximately 20 percent of the radioactivity emerges as angiotensin 11, the remainder as lower homologs. Radioactivity is not retained by the lungs but has the same volume of distribution and mean transit time as blue dextran, a compound unlikely to leave the intravascular space. Plasma membrane fractions of lung are capable of converting angiotensin I to angiotensin II. These data, taken together, indicate the circulating angiotensin I is metabolized by enzymes of the luminal surface of pulmonary endothelial cells.
Development of Cellular Dependence on Infective Organisms: Micrurgical Studies in Amoebas
Authors: Jeon Kwang W.
Published: October 2006

Nuclei and cytoplasm were transferred between a normal strain and a variant strain of Amoeba discoides heavily infected with bacteria. After 5 years of infection, the infective bacteria that were initially harmful to the host cells became harmless, and the nucleus of the host cell became dependent on the infective organisms for its normal functions.
Cooperative Critical Thermal Transition of potassium Accumulation in Smooth Muscle
Authors: Reisin Ignacio L. , Gulati Jagdish
Published: October 2006

The steady-state levels of potassium and sodium of taenia coli of guinea pig are critically affected by varying temperature in the narrow range 12° to 17°C. For the accumulation of both cations the critical temperature, T
c
, is 13.8°C in the presence of 5 millimolar external potassium. The value of T
c
decreases to 10.0°C when the external potassium is raised to 10 millimolar. Since, at a fixed temperature, the potassium accumulation follows a cooperative mechanism, the results are compared with the quantitative predictions of this approach. The critical thermal transition behavior can be described in terms of the cooperative accumulation process.
Brain and Body Temperatures in a Panting Lizard
Authors: Crawford Eugene C.
Published: October 2006

Panting in
Sauromalus obesus
is effective enough to keep deep body temperature (
T
C
) and brain temperature (
T
B
) below an ambient temperature of 45°C for extended periods of time and has a greater cooling effect on the brain than on the remainder of the body. Six animals maintained
T
C
and
T
B
0.9°C (± 0.08 standard error) and 2.7°C (± 0.2 standard error) respectively lower than the ambient temperature of 45°C. It is possible that intracranial vascular shunts play a role in cranial cooling during panting.
Superior Colliculus of the Tree Shrew: A Structural and Functional Subdivision into Superficial and Deep Layers
Authors: Casagrande V. A. , Harting J. K. , Hall W. C. , Diamond I. T. , Martin G. F.
Published: October 2006

Superficial lesions of the superior colliculus produced deficits in form discrimination, while deeper lesions produced, in addition, an inability to track objects. These two syndromes were related to an anatomical subdivision: Superficial lesions resulted in anterograde degeneration in the visual thalamus, whereas lesions confined to the deeper layers produced degeneration in the nonvisual thalamus and in brainstem motor areas.
Behavioral Maintenance of High Concentrations of Blood Ethanol and Physical Dependence in the Rat
Authors: Falk John L. , Samson Herman H. , Winger Gail
Published: October 2006

Rats maintained on an intermittent food schedule with an available ethanol solution drink to excess (13.1 grams of ethanol per kilogram of body weight, daily). Removal of ethanol produces symptoms of physical dependence including death from tonic-clonic seizures. Overindulgence in oral self-administration of an aqueous ethanol solution, resulting in unequivocal physical dependence, approximates a model of human alcoholism.
Absence of Polymerase Protein in Virions of Alpha-Type Rous Sarcoma Virus
Authors: Hanafusa H. , Baltimore D. , Smoler D. , Watson K. F. , Yaniv A. , Spiegelman S.
Published: October 2006

Noninfectious particles of a mutant of Rous sarcoma virus failed to exhibit DNA polymerase activity even with the use of the most sensitive synthetic template-primer complexes. A neutralization blocking test against antibody to DNA polymerase revealed that these mutants did not contain protein immunologically related to the DNA polymerase.
Deficits in Feeding Behavior after Intraventricular Injection of 6-Hydroxydopamine in Rats
Authors: Zigmond Michael J. , Stricker Edward M.
Published: October 2006

Intraventricular injections of 6-hydroxydopamine produced 95 percent depletion of telencephalic norepinephrine and 62 percent depletion of striatal dopamine in rats. Treated rats maintained body weight at subnormal levels and failed to increase food intake in response to a short-term decrease in glucose utilization. After treatment with the monoamine oxidase inhibitor pargyline, 6-hydroxydopamine produced no further norepinephrine depletion but increased the dopamine depletion to 95 percent and produced complete aphagia. These effects are comparable to events that follow bilateral electrolytic lesions of the lateral hypothalamus.
Chromatid Breakage: Differential Effect of Inhibitors of DNA Synthesis during G
2
Phase
Authors: Karon Myron , Benedict William F.
Published: October 2006

The cell cycle specificity of chromatid breakage induced by inhibitors of DNA synthesis depends on the mechanism of drug action. 5-Hydroxy-2-formylpyridine thiosemicarbazone, hydroxyurea, and guanazole, compounds that inhibit ribonucleotide reductase, do not cause chromatid breakage during G
2
phase. In contrast, two active antitumor agents, arabinosylcytosine and 5-azacytidine, which are either incorporated into polynucleotides or affect DNA polymerase, produce chromatid breakage during G
2
phase. All of these agents except guanazole also induce breakage in S phase.
Radio Tracking of Solar Energetic Particles through Interplanetary Space
Authors: Fainberg J. , Evans Larry G. , Stone R. G.
Published: October 2006

Energetic particles ejected from the sun generate radio waves as they travel out through the interplanetary medium. Satellite observations of this emission at long radio wavelengths provide a means of investigating properties of the interplanetary medium, including the gross magnetic field configuration over distances of 1 astronomical unit. Results of such observations are illustrated.
Australia Antigen (Hepatitis B Antigen): A Conformational Antigen Dependent on Disulfide Bonds
Authors: Vyas G. N. , Rao K. R. , Ibrahim A. B.
Published: October 2006

Reduction and alkylation of purified hepatitis-associated Australia antigen (hepatitis B antigen) resulted in a total loss of serologic activity. The reduced and alkylated protein formed a single band with a sedimentation coefficient of 31
S
on analytical ultracentrifugation, and no subunits were detected by Sephadex gel filtration. Although this preparation induced a delayed hypersensitivity response when injected into guinea pigs, it failed to stimulate humoral antibody formation. The data suggest that hepatitis B antigen is a conformational antigen critically dependent upon the disulfide bonds of the protein moiety.
Volatile-Rich Lunar Soil: Evidence of Possible Cometary Impact
Authors: Gibson Everett K. , Moore Gary W.
Published: October 2006

A subsurface Apollo 16 soil, 61221, is much richer in volatile compounds than soils from any other locations or sites as shown by thermal analysis-gas release measurements. A weight loss of 0.03 percent during the interval 175° to 350°C was associated with the release of water, carbon dioxide, methane, hydrogen cyanide, hydrogen, and minor amounts of hydrocarbons and other species. These volatile components may have been brought to this site by a comet, which may have formed North Ray crater.
Detection of Radon Emanation from the Crater Aristarchus by the Apollo 15 Alpha Particle Spectrometer
Authors: Gorenstein Paul , Bjorkholm Paul
Published: October 2006

The alpha particle spectrometer aboard the Apollo 15 command/service module was designed to detect alpha particles from radon decay and to locate regions with unusual activity on the moon. A significant increase in radon-222 activity was detected from a region containing the crater Aristarchus. The result is interpreted as probably indicating internal activity at the site. By analogy with terrestrial processes, increased radon emanation may be associated with the emission of other volatiles.
Putamen: Activity of Single Units during Slow and Rapid Arm Movements
Authors: DeLong M. R.
Published: October 2006

The activity of putamen neurons was studied in a monkey during the performance of both slow and rapid arm movements. More than half of all movement-related units discharged preferentially in relation to slow movements and less than 10 percent in relation to rapid movements. These findings indicate that at least a portion of the basal ganglia (the putamen) is primarily involved in the control of slow movements and are consistent with the hypothesis of Kornhuber that the primary motor function of the basal ganglia is to generate slow ("ramp") rather than rapid ("ballistic") movements.
Dihydrofolate Reductase: X-ray Structure of the Binary Complex with Methotrexate
Authors: Matthews D. A. , Alden R. A. , Bolin J. T. , Freer S. T. , Hamlin R. , Xuong N. , Kraut J. , Poe M. , Williams M. , Hoogsteen K.
Published: October 2006

A central eight-stranded β-pleated sheet is the main feature of the polypeptide backbone folding in dihydrofolate reductase. The innermost four strands and two bridging helices are geometrically similar to but are connected in a different way from those in the dinucleotide binding domains found in nicotinamide-adenine dinucleotide-linked dehydrogenases. Methotrexate is bound in a 15-angstrom-deep cavity with the pteridine ring buried in a primarily hydrophobic pocket, although a strong interaction occurs between the side chain of aspartic acid 27 and N
(1)
, N
(8)
, and the 2-amino group of methotrexate.
Genetic Control of Song Specificity in Crickets
Authors: Hoy Ronald R. , Paul Robert C.
Published: October 2006

The calling song of male field crickets is composed of stereotyped rhythmic pulse intervals, which are predictable expressions of genotype. Females identify conspecific males by their song. Two species of crickets were found to exhibit species-specific song preference, and hybrids between them preferred hybrid calls over either parental call. These results imply genetic control of song reception as well as transmission.
High-Pressure Polymorph of Thulium: An X-ray Diffraction Study
Authors: Liu Lin-Gun , Bassett William A. , Liu Maria S.
Published: October 2006

An x-ray diffraction study of thulium at room temperature and high pressure by means of a diamond-anvil press has shown that thulium transforms from a hexagonal close-packed structure to the samarium type, as other rare-earth elements (gadolinium, terbium, dysprosium, and holmium) do. Unlike the other rare-earth elements, thulium (hexagonal close-packed) has an axial ratio (
c/a
) that is independent of pressure within experimental error and the transition is reversible. The transition occurs with increasing pressure in the range of 60 to 116 kilobars. The lattice parameters of the samarium-type phase of thulium at about 116 kilobars are
a
= 3.327 ± 0.005 angstroms and
c
= 23.48 ± 0.04 angstroms, and the volume change at the transition is estimated to be - 0.5 percent of the volume of the hexagonal close-packed phase at the transition.
Crystal Growth of Silicon and Germanium in Metal Films
Authors: Ottaviani G. , Sigurd D. , Marrello V. , McCaldin J. O. , Mayer J. W.
Published: October 2006

Amorphous silicon in contact with silver films and amorphous germanium in contact with aluminum films form crystalline precipitates when heated to temperatures well below those at which any liquid phase is present. Crystallization occurs by an initial dissolution of the semiconductor into the metal film solvent followed by the growth of crystals out of the solvent.
α
1
-Antitrypsin Deficiency: A Variant with No Detectable α
1
-Antitrypsin
Authors: Talamo Richard C. , Langley Carol E. , Reed Charles E. , Makino Sohei
Published: October 2006

No α
1
-antitrypsin could be detected in the serum of a 24-year-old man with advanced pulmonary emphysema by agarose electrophoresis, immunoelectrophoresis, double diffusion in agarose gel, or α
1
-antitrypsin genetic typing by a combination of starch-gel electrophoresis and crossed antigen-antibody electrophoresis. A circulating α
1
-antitrypsin inactivator could not be demonstrated. Evidence was obtained in family members of genetic transmission of this new α
1
-antitrypsin variant.
Cyclic Adenosine Monophosphate, Metabolites, and Phosphorylase in Neural Tissue: A Comparison of Methods of Fixation
Authors: Lust W. David , Passonneau Janet V. , Veech Richard L.
Published: October 2006

Fixation of rat brain tissue by freeze-blowing, microwave irradiation, immersion of whole rats in liquid nitrogen, and decapitation into liquid nitrogen indicates that postmortem changes in metabolites and enzyme forms are minimal in freeze-blown brains. Cyclic adenosine monophosphate levels are lowest in microwave-irradiated brains, which has been interpreted by some investigators to indicate rapid fixation and minimal anoxia. However, the changes in phosphocreatine, adenosine triphosphate, lactate, and phosphorylase clearly demonstrate that fixation by freeze-blowing or immersion in liquid nitrogen more closely approximate the state in vivo.
Sperm Penetration of Housefly Eggs: Evidence for Involvement of a Female Accessory Secretion
Authors: Leopold Roger A. , Degrugillier Maurice E.
Published: October 2006

Removal of the paired sex accessory glands associated with the posterior reproductive tract of female houseflies inhibited penetration of the eggs by sperm, but the insemination of females without these glands appeared to be unaffected. The results indicate that either the sperm are "activated" or the permeability of the egg membrane is altered by the secretion of the accessory glands before fertilization occurs.
Male Specific Antigen: Homology in Mice and Rats
Authors: Silvers Willys K. , Yang Sen-Lian
Published: October 2006

Male lymphoid cells from some strains of rats can sensitize C57BL/6 female mice against C57BL/6 male skin grafts; this indicates that the male specific antigen of these two species is homologous.
Estrogen-Receptor Interaction
Authors: Jensen Elwood V. , DeSombre Eugene R.
Published: October 2006

The interaction of estradiol with uterine cells involves the association of the hormone with an extranuclear receptor protein, followed by temperature dependent translocation of the resulting complex to the nucleus. During this process, the steroid binding unit of the protein undergoes an alteration, called "receptor transformation," that can be recognized by an increase in its sedimentation rate from 3.8
S
to 5.2
S,
and by its acquisition of the ability to bind to isolated uterine nuclei and to alleviate a tissue specific deficiency in the RNA synthesizing capacity of such nuclei.

Receptor transformation can be effected in the absence of nuclei by warming uterine cytosol with estradiol. This preparation of transformed complex resembles that extracted from nuclei both in its sedimentation rate (5.3
S
) and in its ability to bind to uterine nuclei and augment RNA synthesis, properties that are not shown by the native complex. It is proposed that receptor transformation is an important step in estrogen action and that a principal role of the hormone is to induce conversion of the receptor protein to a biochemically functional form.
Mars: Mariner 9 Spectroscopic Evidence for H
2
O Ice Clouds
Authors: Curran Robert J. , Conrath Barney J. , Hanel Rudolf A. , Kunde Virgil G. , Pearl John C.
Published: October 2006

Spectral features observed with the Mariner 9 interferometer spectrometer are identified as those of H
2
O ice. The measured spectra are compared with theoretical calculations for the transfer of radiation through clouds of ice particles with variations in size distribution and integrated cloud mass. Comparisons with an observed spectrum from the Tharsis Ridge region indicate H
2
O ice clouds composed of particles with a mean radius of 2.0 micrometers and an integrated cloud mass of 5 × 10
-5
gram per square centimeter.
Effects of Dibutyryl Cyclic AMP on Restoration of Function of Damaged Sciatic Nerve in Rats
Authors: Pichichero Michael , Beer Bernard , Clody Donald E.
Published: October 2006

In two experiments, the sciatic nerve of rats was either crushed or hemisected, and N
6
,O
2
-dibutyryl adenosine 3′,5′-monophosphate or saline was injected intramuscularly near the site of the lesion. In both types of nerve damage, the sensorimotor functions of animals treated with N
6
,O
2
-dibutyryl adenosine 3′,5′-monophosphate returned earlier than did those of saline-treated control animals.
Reading and Sentence Completion by a Chimpanzee (
Pan
)
Authors: Rumbaugh Duane M. , Gill Timothy V. , von Glasersfeld E. C.
Published: October 2006

Four studies revealed that a 2½-year-old chimpanzee (
Pan
), after 6 months of computer-controlled language training, proficiently reads projected word-characters that constitute the beginnings of sentences and, in accordance with their meanings and serial order, either finishes the sentences for reward or rejects them.
An Enzymatic Mechanism for the Antithrombotic and Antihemostatic Actions of Aspirin
Authors: Willis Anthony L.
Published: October 2006

Aspirin-type drugs may inhibit irreversible clumping of human blood platelets by blocking the enzymatic conversion of arachidonic acid to a hitherto undiscovered factor, labile aggregation-stimulating substance, which triggers aggregation and to prostaglandin E
2
, which sensitizes the platelets to its aggregatory effects.
High-Frequency C-Type Virus Induction by Inhibitors of Protein Synthesis
Authors: Aaronson Stuart A. , Dunn Claire Y.
Published: October 2006

When inhibitors of protein synthesis are added to BALB/c mouse cells in culture, induction of naturally integrated C-type RNA virus occurs in a high percentage of cells. The action of protein synthesis inhibitors differs from that of halogenated pyrimidines, another class of virus inducers, in their effects on biologically distinguishable viruses. The use of such inhibitors to study integrated virus expression provides a means for studying gene regulation in mammalian cells.
Opaline Sediments of the Southeastern Coastal Plain and Horizon A: Biogenic Origin
Authors: Weaver Fred M. , Wise Sherwood W.
Published: October 2006

Scanning electron microscope techniques show that Eocene opaline claystones (fuller's earth and buhrstone) of the Atlantic and Gulf Coastal Plain, deposits long considered volcanic in origin, are actually highly altered diatomites formed as transgressive facies in normal marine continental shelf environments. These findings are in agreement with a biogenic origin for time-equivalent horizon A and A′′ deep-sea cherts of the North Atlantic and Caribbean.
Jupiter's Clouds: Equatorial Plumes and Other Cloud Forms in the Pioneer 10 Images
Authors: Fountain J. W. , Coffeen D. L. , Doose L. R. , Gehrels T. , Swindell W. , Tomasko M. G.
Published: October 2006

Pioneer 10 images of Jupiter show bright nuclei in the equatorial zone that appear to be thermally driven sources of cloud plume formations.
Biological Suppression of Weeds: Evidence for Allelopathy in Accessions of Cucumber
Authors: Putnam Alan R. , Duke William B.
Published: October 2006

Cucumber (
Cucumis sativus
L.) accessions from 41 nations were grown with two indicator species in a search for superior competitors. Of the plant introductions tested, one inhibited indicator plant growth by 87 percent and 25 inhibited growth by 50 percent or more. The toxicity of leachates from pots containing inhibitory cucumbers to indicator plants germinated in separate containers suggested allelopathy. Incorporation of an allelopathic character into a crop cultivar could provide the plant with a means of gaining a competitive advantage over certain weeds.
Chromosomes of the Chocolate Gourami: A Cytogenetic Anomaly
Authors: Calton Martha S. , Denton Thomas E.
Published: October 2006

The chocolate gourami,
Sphaerichthys osphromonoides
, has the lowest chromosome number reported for fishes, with 2
n
= 16 and
n
= 8. Other members of the family Belontiidae have somatic numbers of 42 to 48. Chromosome instability is demonstrated by the presence of somatic abnormalities and meiotic multivalents.
Peromyscus
: Effect of Early Pairing on Reproduction
Authors: Hill James L.
Published: October 2006

Sibling mating in prairie deer mice (
Peromyscus maniculatus bairdi
) results in poor reproductive performance. Siblings experimentally paired before puberty exhibit delayed reproduction when adult. A behavioral mechanism is involved in this reproductive delay, since prepubertal familiarity also delays reproduction in nonsibling pairs. Such a reproductive delay may act to reduce inbreeding depression and regulate population growth.
Amorphous Solid Water: A Neutron Diffraction Study
Authors: Wenzel Jack , Linderstrøm-Lang C. U. , Rice Stuart A.
Published: October 2006

The structure factor of amorphous solid D
2
O deposited from the vapor at 10°K has been obtained by measuring the neutron diffraction spectrum in the wave vector transfer from 0.8 to 12.3 reciprocal angstroms. The results indicate that the phase investigated is amorphous and has a liquid-like structure factor. The Fourier-transformed structure factor yields a real space pair distribution function consistent with local tetrahedral coordination and hydrogen bonding, as in other condensed phases of water. The intramolecular OD separation is 1.00 angstrom; the lack of data for very large wave vector transfer and the expected near equality of the intramolecular DD separation and intermolecular O . . . D separation make it impossible to determine the intramolecular DOD angle with precision. The neutron scattering data presented are complementary to the x-ray diffraction studies of Venkatesh, Rice, and Narten.
The Terrestrial Magnetosphere: A Half-Wave Rectifier of the Interplanetary Electric Field
Authors: Burton R. K. , McPherron R. L. , Russell C. T.
Published: October 2006

A study of geomagnetic disturbances during 1967 and 1968, for which in situ solar wind observations are available, reveals that the magnetosphere acts as a half-wave rectifier of the interplanetary electric field. The rate of injection of energy into the magnetosphere, as inferred from the strength of the disturbance, is approximately linearly proportional to the component of the electric field from dawn to dusk but is effectively zero if the electric field has a component from dusk to dawn.
Whole Animal Cell Sorting of
Drosophila
Embryos
Authors: Krasnow Mark A. , Cumberledge Susan , Manning Gerard , Herzenberg Leonard A. , Nolan Garry P
Published: October 2006

Use of primary culture cells has been limited by the inability to purify most types of cells, particularly cells from early developmental stages. In whole animal cell sorting (WACS), live cells derived from animals harboring a
lacZ
transgene are purified according to their level of β-galactosidase expression with a fluorogenic β-galactosidase substrate and fluorescence-activated cell sorting. With WACS, incipient posterior compartment cells that express the
engrailed
gene were purified from early
Drosophila
embryos. Neuronal precursor cells were also purified, and they differentiated into neurons with high efficiency in culture. Because there are many
lacZ
strains, it may be possible to purify most types of
Drosophila
cells. The same approach is also applicable to other organisms for which germ-line transformation is possible.
Regulation of the Apolipoprotein AI Gene by ARP-1, a Novel Member of the Steroid Receptor Superfamily
Authors: Ladias John A. A. , Karathanasis Sotirios K.
Published: October 2006

Apolipoprotein AI (apoAI) is a lipid-binding protein that participates in the transport of cholesterol and other lipids in the plasma. A complementary DNA clone for a protein that bound to regulatory elements of the apoAI gene was isolated. This protein, designated apoAI regulatory protein-1 (ARP-1), is a novel member of the steroid hormone receptor superfamily. ARP-1 bound to DNA as a dimer, and its dimerization domain was localized to the COOH-terminal region. ARP-1 also bound to a thyroid hormone-responsive element and to regulatory regions of the apoB, apoCIII, insulin, and ovalbumin genes. In cotransfection experiments, ARP-1 downregulated the apoAI gene. The involvement of ARP-1 in the regulation of apoAI gene expression suggests that it may participate in lipid metabolism and cholesterol homeostasis.
Hybridization in Situ of SV40 Plaques: Detection of Recombinant Sv40 Virus Carrying Specific Sequences of Nonviral DNA
Authors: Villarreal Luis Perez , Berg Paul
Published: October 2006

The detection and recovery of SV40 genomes containing foreign DNA sequences can be facilitated, and the risk of accidental dispersal reduced, by in situ hybridization and radioautography.
Potassium-Argon Ages from the Galápagos Islands
Authors: Bailey Kimberly
Published: October 2006

Potassium-argon ages of eight volcanic rocks from some of the geologically oldest flows exposed in the Galápagos Archipelago indicate that the Galápagos Islands have a probable maximum age of 3 million years. Rocks from six islands were dated; the oldest are from Española (3.2 ± 0.2), Sante Fe (2.7 ± 0.1), and Plazas (4.2 ± 1.8 million years). The new data suggest that the Galápagos Islands are younger than previously supposed on the basis of marine magnetic anomaly dating, but they are older than most previously dated rocks from the Galápagos.