bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunization with Skin Isografts Taken from Tolerant Mice
Authors: Steinmuller David
Published: October 2006

Skin isografts from mice that were immunologically tolerant to allogeneic tissue had the ability to immunize isogeneic recipients against subsequent skin allografts. The immunizing isografts showed no gross signs of rejection themselves and appeared to be only the vehicles for transplantation antigen. It seems likely that allogeneic leukocytes derived from the spleen and bone marrow cells used to confer tolerance were contained in the skin of the tolerant mice and were transferred by the skin isografts in sufficient numbers to stimulate transplantation immunity.
Glutathione Deficiency in Sheep Erythrocytes
Authors: Smith Joseph E. , Osburn Bennie I.
Published: October 2006

Three sheep have been found that have concentrations of erythrocyte glutathione less than 20 percent of the concentrations in normal sheep; they have no readily apparent hemolytic disorder.
Daily Rhythm in Tyrosine Concentration in Human Plasma: Persistence on Low-Protein Diets
Authors: Wurtman Richard J. , Chou Chuan , Rose Christopher M.
Published: October 2006

The concentration of tyrosine in the plasma of normal males varies diurnally. It is lowest (9.5 ± 0.35 micrograms per milliliter) between 0130 and 0230 hours and rises to a peak of 16.2 ± 0.82 micrograms per milliliter by 1030 hours. This rhythm persists when subjects are maintained for 2 weeks on a diet that is very low in protein.
Diamagnetic Solar-Wind Cavity Discovered behind Moon
Authors: Colburn D. S. , Currie R. G. , Mihalov J. D. , Sonett C. P.
Published: October 2006

Preliminary Ames-magnetometer data from Explorer 35, the lunar orbiter, show no evidence of a lunar bow shock. However, an increase of the magnetic field by about 1.5 gamma (over the interplanetary value) is evident on Moon's dark side, as well as dips in field strength at the limbs. Interpretation of these spatial variations in the field as deriving from plasma diamagnetism is consistent with a plasma void on the dark side, and steady-state
(B =
0
)
magnetic transparency of Moon.
Comparative X-Ray and Neutron Diffraction Study of Bonding Effects in
s
-Triazine
Authors: Coppens P.
Published: October 2006

X-ray and neutron-diffraction data were combined for study of deviations from spherical symmetry of the atomic charge distributions in the small organic molecule
s
-triazine. The results indicate that density has migrated from the atomic regions into the bonds and into the nitrogen lone-pair region. Refinement procedures for x-ray data, which do not take these bonding effects into account, give parameters containing small but measurable errors.
Photoreactivation in vivo of Pyrimidine Dimers in
Paramecium
DNA
Authors: Sutherland B. M. , Carrier W. L. , Setlow R. B.
Published: October 2006

Cells of
Paramecium aurelia
labeled with tritiated thymidine were irradiated with ultraviolet light and then were either exposed to photoreactivating light or kept in the dark as controls. In the controls, the level of thymine-containing pyrimidine dimers did not change, but in cells exposed to photoreactivating light such dimers were destroyed. This is the first demonstration in a eukaryote of in vivo photoreactivation of thymine-containing pyrimidine dimers.
Synthesis of Graphite and Hydrocarbons by Reaction between Calcite and Hydrogen
Authors: Giardini A. A. , Salotti C. A. , Lakner J. F.
Published: October 2006

The reaction of calcite with hydrogen was investigated over a range of pressure, temperature, and time. The reaction initiates at about 500°C. Its primarily temperature-dependent rate proceeds in a crystallographically anisotropic manner, and reaction products are CaO, Ca(OH)
2
, H
2
O, CO, CH
4
, C
2
H
6
, and C (graphite), plus a black solid residue that may be hydrocarbon.
Crescentic Landforms along the Atlantic Coast of the United States
Authors: Dolan Robert , Ferm John C.
Published: October 2006

An uninterrupted series of hierarchically arranged crescentic coastal landforms occurs along the Atlantic coast. Dimensional analysis suggests a geometric relation between order, amplitude, and number. The processes responsible for these features also may be continuous in nature.
Aldrin and Dieldrin: Loss under Sterile Conditions
Authors: Lichtenstein E. P. , Anderson J. P. , Fuhremann T. W. , Schulz K. R.
Published: October 2006

After their application to sterile nutrient agar, both aldrin and dieldrin disappeared rather rapidly from the agar in glass-covered petri dishes. In most instances this disappearance was considerably retarded from agar inoculated with either fungi or bacteria. In the presence of microorganisms, aldrin was also epoxidized into dieldrin. Half of the applied aldrin volatilized from the agar during the first day of incubation; dieldrin volatilized more slowly and at a constant rate.
Norepinephrine: Turnover in Rat Brains after Gonadectomy
Authors: Anton-Tay Fernando , Wurtman Richard J.
Published: October 2006

The rate at which
3
H-norepinephrine disappears from rat brain increases after gonadectomy; the effect is observed 6 days after the operation and 24 hours after introduction of the labeled material; it is not reproduced by hypophysectomy. The content of endogenous brain norepinephrine does not decline after removal of the ovaries or testes; thus synthesis of the catecholamine is probably increased by these procedures.
Snake Food Preference: Innate Intraspecific Geographic Variation
Authors: Dix Michael W.
Published: October 2006

Compared to Florida individuals, a smaller percentage of Massachusetts
Thamnophis sirtalis sirtalis
will accept fish. Both experienced adults and isolated newborn snakes respond similarly; the behavior is innate and correlated with habitat differences between the two localities. Although food preference in
Natrix sipedon
is also innate, geographic variation is not as clearcut.
Sulfur-Containing Nucleoside from Yeast Transfer Ribonucleic Acid: 2-Thio-5(or 6)-uridine Acetic Acid Methyl Ester
Authors: Baczynskyj Lubomir , Biemann K. , Hall Ross H.
Published: October 2006

A nucleoside, isolated from yeast transfer RNA, has been assigned the structure 2-thio-5-uridine acetic acid methyl ester on the basis of high-resolution mass spectrometry, chemical properties, and ultraviolet spectra. The alternate 6-substituted isomeric structure cannot yet be completely ruled out.
Sparse Population Coding of Faces in the Inferotemporal Cortex
Authors: Young Malcolm P. , Yamane Shigeru
Published: October 2006

How does the brain represent objects in the world? A proportion of cells in the temporal cortex of monkeys responds specifically to objects, such as faces, but the type of coding used by these cells is not known. Population analysis of two sets of such cells showed that information is carried at the level of the population and that this information relates, in the anterior inferotemporal cortex, to the physical properties of face stimuli and, in the superior temporal polysensory area, to other aspects of the faces, such as their familiarity. There was often sufficient information in small populations of neurons to identify particular faces. These results suggest that representations of complex stimuli in the higher visual areas may take the form of a sparse population code.
Retrograde Amnesia Produced by Electroconvulsive Shock after Reactivation of a Consolidated Memory Trace
Authors: Misanin James R. , Miller Ralph R. , Lewis Donald J.
Published: October 2006

Rats had a memory loss of a fear response when they received an electroconvulsive shock 24 hours after the fear-conditioning trial and preceded by a brief presentation of the conditioned stimulus. No such loss occurred when the conditioned stimulus was not presented. The memory loss in animals given electroconvulsive shock 24 hours after conditioning was, furthermore, as great as that displayed in animals given electroconvulsive shock immediately after conditioning. This result throws doubt on the assertion that electroconvulsive shock exerts a selective amnesic effect on recently acquired memories and thus that electroconvulsive shock produces amnesia solely through interference with memory trace consolidation.
Vinblastine and Griseofulvin Reversibly Disrupt the Living Mitotic Spindle
Authors: Malawista Stephen E. , Sato Hidemi , Bensch Klaus G.
Published: October 2006

Using polarized light we have studied the effects of various mitotic poisons on mitotic spindles of living
Pectinaria
oocytes; we have studied fixed specimens with phase and electron microscopy. Vinblastine caused attrition and eventual disappearance of spindle structure as rapidly as did colcemid, and subsequent recovery from this treatment was at least as fast as that from colcemid. Griseofulvin, however, was easily the best agent for rapid, reversible, and repeated dissolution of the spindle. Agents that arrest metaphase may act on nondividing cells by interfering with the organization of other gelated structures.
Oxygen-Isotope Analysis of Recent Tropical Pacific Benthonic Foraminifera
Authors: Smith P. B. , Emiliani C.
Published: October 2006

Analysis by the oxygen-isotope method of samples of benthonic Foraminifera, collected at different depths on the continental shelf and slope off western Central America, yielded isotopic temperatures agreeing closely with the temperatures measured in the field. The validity of the oxygen-isotope method as a means of analysis of paleotemperatures is further supported.
Mazama Ash in the Northeastern Pacific
Authors: Nelson C. Hans , Kulm L. D. , Carlson Paul R. , Duncan John R.
Published: October 2006

Volcanic glass in marine sediments off Oregon and Washington correlates with continental deposits of Mount Mazama ash by stratigraphic position, refractive index, and radiocarbon dating. Ash deposited in the abyssal regions by turbidity currents is used for tracing of the dispersal routes of postglacial sediments and for evaluation of marine sedimentary processes.
Prehistoric Use of Fur Seals: Evidence from the Olympic Coast of Washington
Authors: Gustafson Carl E.
Published: October 2006

Archeological excavations on the Olympic Coast of Washington provide evidence that marine mammals, particularly fur seals, constituted a major source of food for inhabitants of this region for more than 2000 years. A recent change in the migratory pattern of the fur seals is suggested by the high percentage of mature males present in prehistoric populations.
Nitrogen-15: Microbiological Alteration of Abundance
Authors: Wellman R. P. , Cook F. D. , Krouse H. R.
Published: October 2006

The abundance of N
15
relative to N
14
is significantly altered during experiments in vitro in which nitrate and nitrite are microbiologically reduced to nitrogen gas. In all studies to date, N
14
O
3
-
and N
14
O
2
-
species have been preferentially reduced. This selectivity has a complex dependence on conditions in the medium. The results are not only relevant to natural variations in N
15
relative to N
14
but should be seriously considered during N
15
tracer studies in soils.
Rupture Mechanism of a Liquid Film
Authors: Liebman Israel , Corry John , Perlee Henry E.
Published: October 2006

The rupture mechanism of edge-supported liquid films appears to involve the viscous and drag energies as well as previously postulated kinetic and surface energies. Although details are obscure, the mechanism appears to involve a liquid-gathering process at the free edge, followed by fragmentation of this thickened edge into drops whose radii are approximately 50 times the film's original thickness.
Krinovite, NaMg
2
CrSi
3
O
10
: A New Meteorite Mineral
Authors: Olsen Edward , Fuchs Louis
Published: October 2006

An unusual new silicate, krinovite, has been discovered within graphite nodules in three iron meteorites. Its ratio of silicon to oxygen of 3 : 10 suggests a rare kind of silicate polymerization. The meteorite nodules in which it occurs exhibit a chemical fractionation that differs from that of both stone meteorites and terrestrial basalt.
Neuronal Correlates of Behavior in Freely Moving Rats
Authors: Komisaruk Barry R. , Olds James
Published: October 2006

Firing patterns of single neurons in the hypothalamus, preoptic area, midbrain reticular system, and hippocampus of awake, freely moving female rats were temporally correlated with exploratory sniffing and vibrissa twitching, feeding, lordosis, locomotion, and (or) arousal. These relationships were remarkably stable during continuous observations lasting many hours. During extended periods when certain of these movements were not performed, the correlated neurons showed no action potentials for minutes at a time. Electrical stimulation at certain recording sites elicited behavior patterns whose spontaneous occurrence was accompanied by neuronal activation. Self-stimulation was elicited from sites spontaneously activated during exploratory behavior.
Paleo-Indian Remains from Laguna de Tagua Tagua, Central Chile
Authors: Montané Julio
Published: October 2006

Bone and stone tools associated with extinct fauna (horse and mastodon) place man's occupation in central Chile at 11,380 ± 320 years ago.
Allergic Encephalomyelitis: Passive Transfer Prevented by Encephalitogen
Authors: Levine Seymour , Hoenig Eugene M. , Kies Marian W.
Published: October 2006

Allergic encephalomyelitis was produced in rats by passive transfer of lymph node cells from donors immunized intradermally with neural tissue or an encephalitogenic basic protein plus adjuvants. The same basic protein, injected intravenously into the recipients before or after transfer of lymph node cells, prevented the disease. Even established lesions were reversed. Inhibition by basic protein was specific for encephalomyelitis; it had no effect on passive transfer of allergic adrenalitis.
Corneal Calcification
Authors: Fine Ben S. , Berkow Joseph W. , Fine Samuel
Published: October 2006

Superficial calcification was produced in the normal rabbit cornea by mild irradiation with a carbon dioxide laser. The calcification was entirely extracellular and closely resembled that observed in human band keratopathy, which was characterized as hydroxyapatite by x-ray diffraction. The electron-microscopic appearance of calcific spherules and conglomerates in early corneal calcification is presented. The calcific spherules arise at the basal plasma membrane surface of the epithelial cells in close relation to their basement membrane.
Structural Pattern in Central Uplifts of Cryptoexplosion Structures as Typified by Sierra Madera
Authors: Wilshire H. G. , Howard Keith A.
Published: October 2006

The pattern of deformation in central uplifts of Sierra Madera and other well-known cryptoexplosion structures indicates that inward as well as upward movement of strata formed the uplifts. This kind of movement is incompatible with structures not of impact origin with which they have been compared. The structural style of cryptoexplosion structures, together with features that suggest shock deformation, supports the belief that they are the eroded roots of impact craters.
Hypothalamic Stimulation of Growth Hormone Secretion
Authors: Frohman Lawrence A. , Bernardis Lee L. , Kant kenneth J.
Published: October 2006

Stimulation of the ventromedial hypothalamic nucleus in rats resulted in increased plasma growth hormone levels within 5 minutes, as measured by radioimmunoassay. Stimulation of the cerebral cortex was without effect. These observations confirm previous results involving destructive lesions and establish the ventromedial nucleus as a hypothalamic locus involved in the control of growth hormone secretion.
Transmission of Experimental Kuru to the Spider Monkey (
Ateles geoffreyi
)
Authors: Gajdusek D. Carleton , Gibbs Clarence J. , Asher David M. , David Edward
Published: October 2006

Clinical signs and pathological changes characteristic of kuru in man and experimental kuru in chimpanzees were observed in two spider monkeys,
Ateles geoffreyi
, after inoculation with brain tissue from a kuru-affected chimpanzee. The incubation period for one of the monkeys was 23 months, and 26 months for the other.
Stress Gradient in Solid Methane at High Pressures
Authors: Stajdohar R. E. , Hettwer P. F. , McCann D. R.
Published: October 2006

The magnitude of the axial pressure gradient at 77°K (11 percent per centimeter) in solid methane compressed along one axis for applied pressures up to 10 kilobars was determined by comparing the electrical resistance of a pair of doped tellurium pressure gages with that of a set of single-crystal gages made of high-purity bismuth. The existence of the pressure gradient revealed the causes of deformation in metal tensile specimens embedded in solid methane and cycled to high pressure.
Discrimination Learning as the Summation of Excitation and Inhibition
Authors: Hearst Eliot
Published: October 2006

Pigeons received either excitatory, inhibitory, or combined excitatory and inhibitory (intradimensional) training to discriminate line-tilt stimuli. Algebraic summation of relative-generalization gradients obtained after separate excitatory and inhibitory training sessions was used to predict characteristics of gradients after intradimensional training. The good agreement between obtained and predicted gradients provided support for gradient-interaction theory.
Alpha-Chain Disease: A New Immunoglobulin Abnormality
Authors: Seligmann Maxime , Danon Françoise , Hurez Daniel , Mihaesco Edith , Preud'homme Jean-Louis
Published: October 2006

A new type of pathological immunoglobulin was found in the serum, urine, and saliva of a young Arab patient with abdominal lymphoma and diffuse lymphoplasmacytic infiltration of the small intestine. This protein is devoid of light chains and is closely related to the alpha polypeptide chains of the γ
A1
(Le) subclass of immunoglobulin A. It is characterized by electrophoretic heterogeneity, tendency toward polymerization, and a high carbohydrate content. No intracellular synthesis of light chain was detected.
Progesterone Antagonism of Estrogen-Induced Cytodifferentiation in Chick Oviduct
Authors: Oka Takami , Schimke Robert T.
Published: October 2006

Progesterone administered with estrogen to the intact female chick antagonizes the characteristic effects of estrogen to induce cell proliferation and cytodifferentiation of tubular gland cells in the oviduct, events that are accompanied by the appearance of lysozyme. Progesterone appears to exert its effect by preventing proliferation of cells destined to become tubular gland cells, but once such cells do proliferate, subsequent cytodifferentiation and appearance of lysozyme are not prevented.
Intellectual Deficit Associated with Transplacentally Induced Microcephaly in the Rat
Authors: Haddad R. K. , Rabe Ausma , Laqueur Gert L. , Spatz Maria , Valsamis Marius P.
Published: October 2006

Fischer rats injected with methylazoxymethanol late in pregnancy produce young with considerably reduced cerebral hemispheres. They appear normal otherwise. As adults these animals make many more errors in the Hebb-Williams maze than do control animals.
Pistillate Papaya Flower: A Morphological Anomaly
Authors: Storey William B.
Published: October 2006

The pistillate flower of
Carica papaya
is a pleurogynous unisexual form derived intraspecifically from a perigynous bisexual ancestor. It is a morphological anomaly in that the ovary consists of two cycles of carpels which, in the ancestor, arise on the receptacle at different levels as dissimilar orders of organs. The bulk of the pentamerous ovary and the dorsal carpellary vascular system are derived from a cycle of five stamens in the ancestor. The ventral carpellary system is inherited intact from the ancestor which has normal morphology in the sense that the carpels consist of a single cycle of sporophylls.
Lizard Reflectivity Change and Its Effect on Light Transmission through Body Wall
Authors: Porter Warren P. , Norris Kenneth S.
Published: October 2006

Light transmission through the body wall of living, color-labile desert iguanas (
Dipsosaurus dorsalis
) was measured by spectrophotometry. In the dark phase, the body wall's absorption of ultraviolet light and visible light was approximately twice that of the body wall in the light phase. The shorter wavelengths of ultraviolet could penetrate the body wall in the light phase but not in the dark phase. The intensity and wavelengths of light which could penetrate the body wall without pigments are potentially mutagenic when judged by bacterial standards.
Nucleotide Sequence of
Escherichia coli
Tyrosine Transfer Ribonucleic Acid
Authors: Doctor B. P. , Loebel Judith E. , Sodd Mary Ann , Winter David B.
Published: October 2006

The nucleotide sequence of one of the
Escherichia coli
tyrosine-transfer ribonucleic acids was determined in order to compare its sequence with that of yeast tyrosine-transfer ribonucleic acid. Forty-four positions of both transfer ribonucleic acids are occupied by the same nucleotides if they are arranged in the manner shown here. The information obtained suggests that the conformation of transfer ribonucleic acid molecules may be a greater contributing factor than a specific nucleotide sequence in the interaction of transfer ribonucleic acid with its corresponding aminoacyl-transfer ribonucleic acid synthetase.
Plague Bacillus: Survival within Host Phagocytes
Authors: Janssen Werner A. , Surgalla Michael J.
Published: October 2006

Pasteurella pestis
within neutrophiles and macrophages removed from the peritoneal cavity of guinea pigs during experimental plague were shown to be viable by direct microscopic observation of the infected phagocytes incubating in suitable bacteriologic media. The time-honored hypothesis that the major determinant of the virulence of the plague bacillus is its ability to resist ingestion by phagocytes must be reevaluated.
Leukotactic Factor Produced by Sensitized Lymphocytes
Authors: Ward Peter A. , Remold Heinz G. , David John R.
Published: October 2006

Lymph node lymphocytes obtained from guinea pigs exhibiting delayed hypersensitivity are stimulated in vitro by specific antigen to produce a soluble factor that is chemotactic in vitro for mononuclear macrophages. The material is nondialyzable, relatively heat stable, and elutes from Sephadex G-100 in the fraction containing molecules smaller than immunoglobulins.
Adrenal Cholesterol: Localization by Electron-Microscope Autoradiography
Authors: Moses Harold L. , Davis Warren W. , Rosenthal Alan S. , Garren Leonard D.
Published: October 2006

As determined by electron-microscope autoradiography of adrenal glands containing tritiated cholesterol and by modified differential centrifugation techniques, 70 to 80 percent of adrenal cholesterol is contained within lipid droplets of rat adrenal cortical cells.
Mapping of Deletions and Substitutions in Heteroduplex DNA Molecules of Bacteriophage Lambda by Electron Microscopy
Authors: Westmoreland Barbara C. , Szybalski Waclaw , Ris Hans
Published: October 2006

Electron microscopy of heteroduplex DNA molecules, composed of one strand of
Escherichia coli
phage λ
+
DNA annealed to the complementary DNA strand of a λ deletion or substitution mutant, permits visualization, as well as precise measurements and mapping, of the unpaired single-stranded regions of nonhomology in the otherwise double-stranded molecules. In the λb2 mutant, the central segment (13 percent) of the λ
+
DNA molecule is shown to be deleted. In the hybrid phages λ
i
434
and λ
i
21
a segment of the right arm of the λ
+
genome (5.5 or 7.6 to 9 percent) is replaced by the corresponding immunity regions of phage 434 (3.3 percent or phage 21 (4 percent) DNA. The b5 region in the λb5 mutant appears to be identical to the
i
21
segment. From these data it is possible to estimate the size and position of those λ genes which are replaced by the
i
434
and
i
21
segments. The method permits preparing complete physical maps of viral genomes with a precision heretofore unattainable.
Sleep and Cardiac Rhythm in the Gray Seal
Authors: Ridgway S. H. , Harrison R. J. , Joyce P. L.
Published: October 2006

Telemetric studies of electroencephalograms, electrocardiograms, and electrooculograms and concurrent observations of behavior revealed that seals can sleep underwater, on the surface, or while hauled out. Rapid eye movement preceded slow wave sleep and was accompanied by increased respiratory rate and rhythmic tachycardia. While slow wave sleep occurred under all sleep conditions, rapid eye movement occurred only when a seal was hanging at the water surface or hauled out, never underwater.
Stress-Induced Facilitation of Classical Conditioning
Authors: Shors Tracey J. , Weiss Craig , Thompson Richard F.
Published: October 2006

Stress has been shown to impair subsequent learning. To determine whether stress would impair classical conditioning, rats were exposed to inescapable, low-intensity tail shock and subsequently classically conditioned under freely moving conditions with a brief periorbital shock unconditioned stimulus and a white noise conditioned stimulus. Unexpectedly stressed rats exhibited significantly more conditioned eyeblink responses and the magnitude of their individual responses was also enhanced. These results stand in contrast to the learning deficits typically observed and suggest that stress can enhance the acquisition of discrete conditioned responses.
Equilibration of Atmospheric Carbon Dioxide with Sea Water: Possible Enzymatic Control of the Rate
Authors: Berger Rainer , Libby W. F.
Published: October 2006

Surface and subsurface ocean water differ in exchange characteristics with atmospheric carbon dioxide. The possibility of control by an enzyme like carbonic anhydrase has been experimentally explored.
Cebus
Monkeys: Effect on Branching of
Gustavia
Trees
Authors: Oppenheimer John R. , Lang Gerald E.
Published: October 2006

One 50-tree site with monkeys and one without were similar with respect to tree height and tree diameter, but the site with monkeys had trees with significantly more branches than those on the site without monkeys. Possibly removal of terminal buds during feeding by the monkeys releases the lateral buds from apical dominance and allows increased branching.
Indole(ethyl)amine
N
-Methyltransferase in the Brain
Authors: Morgan Merrily , Mandell Arnold J.
Published: October 2006

An enzyme which
N
-methylates various indole(ethyl)amine substrates was isolated from brain, separated from the pituitary and the pineal glands. It appeared localized in the supernatant and synaptosomal areas after discontinuous sucrose-gradient ultracentrifugation. This is the first demonstration of the enzyme in brain.
Induction in vitro of Microtubular Crystals by Vinca Alkaloids
Authors: Bensch Klaus G. , Marantz Robert , Wisniewski Henryk , Shelanski Michael
Published: October 2006

The addition of vinblastine or vincristine to solutions of pure microtubule protein or to supernatants from high-speed centrifugation of rabbit-brain homogenates results in the formation of a fine precipitate. Examination of this precipitate by electron microscopy reveals ordered structures with areas of ladder-like configuration.
Carbon: Observations on the New Allotropic Form
Authors: Whittaker A. Greenville , Kintner P. L.
Published: October 2006

The recently characterized "white" allotropic form of carbon has been produced at high temperature and low pressure during graphite sublimation. Under free-vaporization conditions above ∼2550°K, the white carbon forms as small transparent crystals on the edges of the basal planes of graphite. The interplanar spacings of this material are identical to those of a carbon form noted in graphitic gneiss from the Ries Crater.
Perineurium: Evidence for Contractile Elements
Authors: Ross Michael H. , Reith Edward J.
Published: October 2006

Electron-microscopic study of mouse sciatic nerve reveals that perineurial cells contain filaments and associated opaque regions similar to those observed in smooth muscle. This finding is consistent with observations which suggest that nerve might have a contractile property. In addition to their function in maintaining the connective tissue stroma of perineurium, as well as being a selective diffusion barrier, perineurial cells may serve the nerve in a contractile capacity.
Rabbit Lateral Geniculate Nucleus: Sharpener of Directional Information
Authors: Levick W. R. , Oyster C. W. , Takahashi Ellen
Published: October 2006

Direction-selective neurons in the rabbit lateral geniculate nucleus signal movement-direction more precisely than their retinal counterparts. This increased selectivity arises from the interaction of retinal inputs to the geniculate cell. A direction-selective geniculate neuron is fed by at least two retinal direction-selective cells, whose preferred directions are 180 degrees apart. One retinal input is excitatory to the geniculate cell and the other is inhibitory.
Bird Migration: Influence of Physiological State upon Celestial Orientation
Authors: Emlen Stephen T.
Published: October 2006

By means of photoperiod manipulation, the physiological states of spring and autumn migratory readiness were induced in indigo buntings. The orientational tendencies of these two groups of birds were tested simultaneously in May 1968, under an artificial, spring planetarium sky. Birds in spring condition oriented northward; those in autumnal condition, southward. These results suggest that changes in the internal physiological state of the bird rather than differences in the external stimulus situation are responsible for the seasonal reversal of preferred migration direction in this species.
Renal Concentrating Mechanism: Possible Role for Sodium-Potassium Activated Adenosine Triphosphatase
Authors: Martinez-Maldonado M. , Allen J. C. , Eknoyan G. , Suki W. , Schwartz A.
Published: October 2006

Sodium-potassium activated adenosine triphosphatase activity was found to be almost twice as high in renal medulla as in cortex. Infusion of digoxin, a specific inhibitor of the enzyme, into one renal artery of the dog resulted in unilateral natriuresis, impaired concentrating capacity, and reduction of the enzyme activity in both cortex and medulla. It is suggested that the sodium-potassium adenosine triphosphatase plays an important role in urine concentration mechanisms.
X-ray Resistant Cell Required for the Induction of in vitro Antibody Formation
Authors: Roseman Jeffrey
Published: October 2006

Mouse spleen cells were separated into two populations on the basis of adherence to plastic. The recombination of these two populations was required for the in vitro antibody response to sheep erythrocytes. By separating the two populations from x-irradiated mice and combining each with the other population prepared from normal mice, it was demonstrated that the immunologic function of the nonadherent population only was highly sensitive to x-ray injury. In contrast, x-irradiation in doses as high as 1000 roentgens had no measurable effect on the immune function of adherent cells, that is, the population which first interacts with antigen and is composed principally of large phagocytic cells.
Possible Horizontal Transfer of
Drosophila
Genes by the Mite
Proctolaelaps regalis
Authors: Houck Marilyn A. , Clark Jonathan B. , Peterson Kenneth R. , Kidwell Margaret G.
Published: October 2006

There is strong inferential evidence for recent horizontal gene transfer of the P (mobile) element to
Drosophila melanogaster
from a species of the
Drosophila willistoni
group. One potential vector of this transfer is a semiparasitic mite,
Proctolaelaps regalis
DeLeon, whose morphology, behavior, and co-occurrence with
Drosophila
are consistent with the properties necessary for such a vector. Southern blot hybridization, polymerase chain reaction (PCR) amplification, and DNA sequencing showed that samples of
P. regalis
associated with a P strain of
D. melanogaster
carried P element sequences. Similarly,
Drosophila
ribosomal DNA sequences were identified in
P. regalis
samples that had been associated with
Drosophila
cultures. These results have potentially important evolutionary implications, not only for understanding the mechanisms by which genes may be transferred between reproductively isolated species, but also for improved detection of some host-parasite and predator-prey relationships.
Negative Regulation of CD45 Protein Tyrosine Phosphatase Activity by Ionomycin in T Cells
Authors: Ostergaard Hanne L. , Trowbridge Ian S.
Published: October 2006

CD45 is a leukocyte-specific, transmembrane protein tyrosine phosphatase (PTPase) required for T cell responsiveness. How the activity of PTPases is regulated in vivo is unclear. Treatment of murine thymocytes and a variety of murine T cell lines with the calcium ionophore ionomycin decreased CD45 PTPase activity. Ionomycin treatment also led to a decreased phosphorylation of serine residues in CD45. These results indicate that increased intracellular calcium modulates CD45 PTPase activity, demonstrating regulation of CD45 PTPase activity in vivo, and also implicate serine dephosphorylation as a possible mechanism.
Activity-Dependent Synaptic Competition in Vitro: Heterosynaptic Suppression of Developing Synapses
Authors: Lo Yi-Jiuan , Poo Mu-ming
Published: October 2006

The development and stability of synaptic connections in the nervous system are influenced by the pattern of electrical activity and the competitive interaction between the adjacent nerve terminals. To investigate this influence, a culture system of nerve and muscle cells has been developed in which a single embryonic muscle cell is coinnervated by two spinal neurons. The effect of electrical activity on the synaptic efficacy was examined after repetitive electrical stimulation was applied to one or both neurons. Brief tetanic stimulation of one neuron resulted in immediate functional suppression of the synapse made by the unstimulated neuron innervating the same muscle cell. This heterosynaptic suppression was largely absent when the tetanic stimulation was applied concurrently to both neurons. This result demonstrates that activity-dependent synaptic competition can be studied in vitro at a cellular level.
Carbon Monoxide: Residence Time in the Atmosphere
Authors: Weinstock Bernard
Published: October 2006

A lower limit of 0.1 year for the residence time of carbon monoxide in the atmosphere is derived from radiocarbon measurements. The action of certain microorganisms and atmospheric photochemical reactions are possible mechanisms for the removal of carbon monoxide. This value can be compared with 2.7 years, a value deduced from estimated rates of carbon monoxide production and global measurements of atmospheric concentrations of carbon monoxide.
Androgen Accumulation and Binding to Macromolecules in Seminal Vesicles: Inhibition by Cyproterone
Authors: Stern Judith M. , Eisenfeld Arnold J.
Published: October 2006

Cyproterone reduces the accumulation of testosterone and dihydrotestosterone in seminal vesicles 30 minutes after intravenous administration of tritiated testosterone to castrated rats. Testosterone, added in vitro, binds to macromolecules from the supernatant fraction of the seminal vesicle homogenates; this interaction is antagonized competitively by cyproterone. Cyproterone may diminish androgenic effects by competition for binding molecules.
Size Adaptation: A New Aftereffect
Authors: Blakemore Colin , Sutton Peter
Published: October 2006

If, after prolonged observation of a striped pattern, one views a grating of the same orientation with somewhat narrower bars, then the bars seem even thinner than in fact they are. Broader bars seem broader still. This finding implies a system of size-detecting channels in human vision. The phenomenon may underlie many of the classical figural aftereffects.
Thermal Stratification in the Arctic Ocean
Authors: Neal Victor T. , Neshyba Stephen , Denner Warren
Published: October 2006

Fine scale measurements of the vertical temperature profile in an Arctic water column show the presence of several cascaded isothermal layers. Layers between the depths of 300 and 350 meters range from 2 to 10 meters in thickness, while the temperature change between adjacent layers is approximately 0.026°C. The individual layers are isothermal to within ± 0.001°C.
Axonal Transport of Proteins in Experimental Neuropathies
Authors: Pleasure David E. , Mishler Kathleen C. , Engel W. King
Published: October 2006

Axoplasmic flow of proteins is interrupted in cats with neuropathy induced by acrylamide, but it is not interrupted in normal cats and in those with neuropathy induced by tri-orthocresyl phosphate. The proteins move from lumbosacral motor neurons along the ventral roots and from ganglion cells toward the spinal cord along the dorsal roots at about 1½ millimeters per day.
Acid Polysaccharides from Invertebrate Connective Tissue: Phylogenetic Aspects
Authors: Katzman Richard L. , Jeanloz Roger W.
Published: October 2006

Polyfucose sulfate and a chondroitin sulfate were isolated from echinoderm connective tissue. Coelenterate and poriferan connective tissues were devoid of these acid polysaccharides.
Sex Pheromones Produced by Male Boll Weevil: Isolation, Identification, and Synthesis
Authors: Tumlinson J. H. , Hardee D. D. , Gueldner R. C. , Thompson A. C. , Hedin P. A. , Minyard J. P.
Published: October 2006

The response of female boll weevils to males,
Anthonomus grandis
Boheman, in laboratory bioassays can be reproduced by exposure to a mixture of compounds I, II, and either III or IV, all isolated from male weevils and their fecal material. The same response was elicited by mixtures of the synthesized compounds. Compound I is (+)-
cis
-2-isopropenyl-1-methylcyclobtutaneethanol; II,
cis
-3,3-dimethyl-Δ
1,β
-cyclohexaneethanol; III,
cis
-3,3-dimethyl-Δ
1,α
-cyclohexaneacetaldehyde; and IV,
trans
-3,3-dimethyl-Δ
1,α
-cyclohexaneacetaldehyde.
Alpha-Naphthoflavone: An Inhibitor of Hydrocarbon Cytotoxicity and Microsomal Hydroxylase
Authors: Diamond Leila , Gelboin H. V.
Published: October 2006

Alpha-naphthoflavone inhibits the metabolism of 3,4-benzopyrene and 7,12-dimethylbenz(
a
)anthracene in hamster embryo cell cultures and protects the cells against the inhibition of cell multiplication by these carcinogens. Alpha-naphthoflavone also inhibits the aryl hydrocarbon hydroxylase activity in homogenates of induced hamster embryo cells and in liver microsomes from rats previously treated with polycyclic aromatic hydrocarbons, but not in microsomes from control rats.
Mars: Is the Surface Colored by Carbon Suboxide?
Authors: Plummer William T. , Carsont Robert K.
Published: October 2006

The reflection spectrum of Mars can be well matched from 0.2 through 1.6 microns (and farther) by polymers of carbon suboxide, reflection spectra for which have now been measured. We propose that the reddish color of Mars might be attributed to carbon suboxide, not the commonly considered limonite or other iron-bearing minerals.
Crystal Orientation and Plate Structure in Echinoid Skeletal Units
Authors: Nissen Hans-Ude
Published: October 2006

The submicroscopic morphology of magnesian calcite skeletal units of echinoids, revealed by scanning electron microscopy, was compared with crystal orientation data obtained by x-ray methods and with macroscopic morphology. The Perischoechinoidea and the Euechinoidea differ with regard to the shapes of their trabeculae. Nearly all plates and spines are single crystals. A variety of different directional relations of
c
- and
a
-axes to the main morphological directions are found for different species; adjacent plates with identical
c
-axis orientation differ strongly in orientation of their
a
-axes. Fracture surfaces of single trabeculae show cleavage planes and zonal layers attributed to changes in secretion conditions.
Acetyl Coenzyme A Carboxylase: Filamentous Nature of the Animal Enzymes
Authors: Kleinschmidt Albrecht K. , Moss Joel , Lane M. Daniel
Published: October 2006

Acetyl coenzyme A carboxylases purified from several animal tissues exist as enzymatically active polymeric filaments of high molecular weight and have similar electron microscopic, hydrodynamic, and catalytic properties. These filaments reversibly dissociate into inactive protomers of uniform size. Their reassembly into catalytically active filaments is promoted by the presence of an allosteric activator.
Plus and Minus Single-Stranded DNA Separately Encapsidated in Adeno-Associated Satellite Virions
Authors: Mayor Heather D. , Torikai Katsutaka , Melnick Joseph L. , Mandel Manley
Published: October 2006

Based on physical and chemical determinations, the molecular weight of the type 4 adeno-satellite virus is 5.4 × 10
6
daltons, and the virion contains 1.4 × 10
6
daltons of DNA. Denaturation and renaturation studies indicate that the viral genome is a single-stranded DNA molecule and that each virion contains either a minus or a plus strand. Upon extraction, the minus and plus strands unite to form double-stranded DNA molecules with no obvious excess of unpaired strands.
Permeability and Structure of Junctional Membranes at an Electrotonic Synapse
Authors: Payton B. W. , Bennett M. V. L. , Pappas G. D.
Published: October 2006

The dye Procion Yellow M4RS crosses junctional membranes from cytoplasm to cytoplasm at electrotonic synapses between segments of the crayfish septate axon. The dye does not enter the cells from extracellular space. Thus permeability of junctional membranes is qualitatively different from that of nonjunctional membranes. Electron microscopy after fixation in the presence of lanthanum hydroxide indicates that these synapses are "gap junctions" and that there is a network of channels continuous with extracellular space between apposed junctional membranes. These channels must be interlaced with intercytoplasmic channels that are not open to extracellular space.
Buoyancy Control in the Freshwater Turtle,
Pseudemys scripta elegans
Authors: Jackson Donald C.
Published: October 2006

Freshwater turtles (
Pseudemys scripta elegans
) significantly corrected experimental displacements of their specific gravity. By reciprocally changing the volumes of lung air and stored water, they set their buoyancy and maintained their body volume. The cloacal bursae may be the active site for water storage and exchange in this mechanism.
Inheritance of a Cardiac Arterial Asymmetry in Mice
Authors: Bruell Jan H. , Leininger J. Thomas , Hellerstein Herman K.
Published: October 2006

A pair of coronary arteries supplies the interventricular septum of the heart of
Mus musculus
. The members of this pair tend to be of unequal size, which permits distinction between specimens displaying left asymmetry and those showing right asymmetry. Three inbred strains (C57BL/10, DBA/1, and Balb/c) differ with regard to this asymmetry. However, variation exists within strains, which suggests that nongenetic factors also influence the development of the asymmetry. Right arterial asymmetry is dominant over left asymmetry.
Abundances of 30 Elements in Lunar Rocks, Soil, and Core Samples
Authors: Schmitt Roman A. , Wakita Hiroshi , Rey Plinio
Published: October 2006

Abundances of 30 elements in seven lunar rocks and soil were determined by instrumental and radiochemical activation analysis. Seven major and minor elements in chips from 27 rocks were determined by instrumental activation analysis. Abundances of ten bulk elements overlap for the breccia rocks and soil samples. All lunar rare earth elements distribution patterns resemble those found in terrestrial abyssal subalkaline basalt, but with Eu depleted by about 60 percent in all lunar samples compared to the adjacent rare earth elements. Precipitation of plagioclase and hypersthene achondritic-like minerals from a melt could account for Eu depletion and the observed distribution of rare earth elements. Abundances of Ti, Al, Ca, Na, and Mn determined by instrumental activation analysis in five core-tube soil samples indicate uniformity for Al and Mn and apparent differences (10 to 20 percent) for Ti, Ca, and Na at 7.8 and 10.5 centimeters as compared to 0 to 5.2 centimeter depths.
Trapped Solar Wind Noble Gases, Kr
81
/Kr Exposure Ages and K/Ar Ages in Apollo 11 Lunar Material
Authors: Eberhardt P. , Geiss J. , Graf H. , Grögler N. , Krähenbühl U. , Schwaller H. , Schwarzmüller J. , Stettler A.
Published: October 2006

Grain size and etching experiments show that the fine lunar material contains large amounts of trapped solar wind particles. Elemental and isotopic compositions of the noble gases in solar material and in the terrestrial atmosphere are significantly different, except for the Ar
36
/ Ar
38
and the Kr isotope ratios. Exposure ages of two rocks and of the fine material are between 380 and 510 × 10
6
years. Feldspar concentrates give K/Ar ages of 3220 and 3300 × 10
6
years, significantly higher than the unseparated rock.
Crystallization of Some Lunar Mafic Magmas and Generation of Rhyolitic Liquid
Authors: Kushiro Ikuo , Nakamura Yasuo , Haramura Hiroshi , Akimoto Syun-ichi
Published: October 2006

During crystallization of lunar crystalline rocks 10022 and 10024, augite changes in composition almost continuously from titanaugite (∼ Ca
36
Mg
47
Fe
17
with TiO
2
∼3 percent) to a very iron-rich variety (Ca
9
Mg
5
Fe
86
), pigeonite changes from Ca
9
Mg
66
Fe
25
to Ca
10
Mg
51
Fe
39
, and olivine changes (in 10022) from Mg
71
Fe
29
to Mg
41
Fe
59
, whereas plagioclase stays as bytownite. These compositional variations, as well as the textural relations, may be explained by rapid crystallization of undercooled magmas. The residual liquids found as mesostasis are rhyolitic, which suggests that fractional crystallization of some lunar mafic magmas can generate rhyolitic magmas. Melting experiments were made on crystalline rocks to determine liquidus temperatures and crystallizing phases.
Rangia cuneata
on the East Coast: Thousand Mile Range Extension, or Resurgence?
Authors: Hopkins Sewell H. , Andrews Jay D.
Published: October 2006

Rangia cuneata
, a valuable clam of the estuarine zone where fluctuating salinities (from 0 to 15 parts per thousand) exclude most animals, is now developing large populations in many estuaries from Florida to Maryland. Before 1955 it was thought to be extinct on the East Coast since the Pleistocene and to be living only in Gulf Coast estuaries.
Metabolic Dependence of Fast Axoplasmic Transport in Nerve
Authors: Ochs Sidney , Ranish N.
Published: October 2006

Fast axoplasmic transport, shown in cat sciatic nerves by a crest of labeled activity after injection of the L7 ganglion with [
3
H]-leucine or [
3
H]-lysine, was stopped within 15 minutes after death of the animals by bleeding. If the sciatic nerves were removed from the animals and placed in a chamber supplied with oxygen at 38 degrees centigrade, fast transport was sustained. Transport was rapidly blocked in similar in vitro preparations when the nerves were kept in a nitrogen environment. Fast axoplasmic transport is closely dependent upon oxibdative metabolism.
Pseudohermaphrodite Rat: End Organ Insensitivity to Testosterone
Authors: Bardin C. Wayne , Bullock Leslie , Schneider George , Allison John E. , Stanley Allan J.
Published: October 2006

The pseudohermaphrodite rat is characterized by lack of androgen-dependent differentiation. Treatment of these rats with testosterone failed to produce the expected changes in preputial and adrenal gland weights and in hexobarbital metabolism. This insensitivity of the end organ to testosterone could not be explained by defective formation of dihydrotestosterone.
Neuronal Soma and Whole Neuroglia of Rat Brain: A New Isolation Technique
Authors: Norton William T. , Poduslo Shirley E.
Published: October 2006

Minced rat brain softened by treatment with trypsin is disrupted by filtration through nylon and steel meshes to produce a suspension of free-floating cells and debris. The cells are separated and purified by centrifugation on discontinuous sucrose gradients. Preparations of neuronal perikarya, retaining stumps of processes, so obtained are 90 percent pure and yield 33.6 × 10
6
cells per brain (3 milligrams, dry weight). The glial cells, apparently intact with extensive branched processes, are about 70 percent pure by weight and are obtained in a yield of 6.6 × 10
6
cells per brain (2 milligrams dry weight). The neurons are smaller and have less lipid than the glial cells.