bluuebunny/crossref_metadata_2025 huggingface dataset:
Selection of a Ribozyme That Functions as a Superior Template in a Self-Copying Reaction
Authors: Green Rachel , Szostak Jack W.
Published: October 2006

The
sunY
ribozyme is derived from a self-splicing RNA group I intron. This ribozyme was chosen as a starting point for the design of a self-replicating RNA because of its small size. As a means of facilitating the self-replication process, the size of this ribozyme was decreased by the deletion of nonconserved structural domains; however, when such deletions were made, there were severe losses of enzymatic activity. In vitro genetic selection was used to identify mutations that reactivate a virtually inactive
sunY
deletion mutant. A selected mutant with five substitution mutations scattered throughout the primary sequence showed greater catalytic activity than the original ribozyme under the selection conditions. The
sunY
ribozyme and its small selected variant can both catalyze template-directed oligonucleotide assembly. The small size and reduced secondary structure of the selected variant results in an enhancement, relative to that of the original ribozyme, of its rate of self-copying. This engineered ribozyme is able to function effectively both as a catalyst and as a template in self-copying reactions.
Targeted Degradation of c-Fos, But Not v-Fos, by a Phosphorylation-Dependent Signal on c-Jun
Authors: Papavassiliou Athanasios G. , Treier Mathias , Chavrier Catherine , Bohmann Dirk
Published: October 2006

The proto-oncogene products c-Fos and c-Jun heterodimerize through their leucine zippers to form the AP-1 transcription factor. The transcriptional activity of the heterodimer is regulated by signal-dependent phosphorylation and dephosphorylation events. The stability of c-Fos was found to also be controlled by intracellular signal transduction. In transient expression and in vitro degradation experiments, the stability of c-Fos was decreased when the protein was dimerized with phosphorylated c-Jun. c-Jun protein isolated from phorbol ester-induced cells did not target c-Fos for degradation, which suggests that c-Fos is transiently stabilized after stimulation of cell growth. v-Fos protein, the retroviral counterpart of c-Fos, was not susceptible to degradation targeted by c-Jun.
Temperature Dependence of Carbon Isotope Composition in Marine Plankton and Sediments
Authors: Sackett William M. , Eckelmann Walter R. , Bender Michael L. , Bé Allan W. H.
Published: October 2006

Samples of marine plankton collected in high-latitude areas of the South Atlantic where surface water temperatures are near 0°C show a carbon-12 enrichment of 6 per mill relative to samples collected where temperatures are about 25°C. The organic carbon in sediments in the Drake Passage and Argentine Basin also shows a carbon-12 enrichment relative to warmer areas.
Histone Regulation of Lactic Dehydrogenase in Embryonic Chick Brain Tissue
Authors: Goodwin B. C. , Sizer I. W.
Published: October 2006

Histone, when added at low concentrations to cultures of embryonic chick brain tissue, causes an inductive response in lactic dehydrogenase activity, whereas at higher concentrations of histone the response is repressive. This control is shown to operate by altering protein synthesis. Thus, histones exercise a primary regulatory function in the chick. Unlike lactic dehydrogenase, acetylcholine esterase is stable in this system and is not affected by histones or inhibitors of protein synthesis.
Cerebellar Disease in Cats Induced by Inoculation of Rat Virus
Authors: Kilham Lawrence , Margolis George
Published: October 2006

Rat virus selectively destroys the external germinal layer of the cerebellar cortex when inoculated intracerebrally into newborn cats. The lesions are marked by numerous intranuclear inclusion bodies and a rise of virus titers. These effects suggest that the spontaneous ataxia of cats which is accompanied by cerebellar hypoplasia, may be of viral origin.
Adaptation to Prismatically Rotated Visual Fields
Authors: Morant Ricardo B. , Beller Henry K.
Published: October 2006

The aftereffects of viewing a tilted field of lines differ from the effects of viewing a tilted field of objects. The difference is attributed to the fact that unlike isolated lines, objects have specifiable normal orientations.
Photoreception and Entrainment of Cockroach Activity Rhythms
Authors: Roberts Shepherd K.
Published: October 2006

In the cockroach there are two distinct sets of photoreceptors—the compound eyes and the ocelli—which may function as a sensory input whereby circadian locomotor rhythms are entrained by environmental light cycles. Surgical removal of the ocelli did not interfere with normal entrainment, but covering over the compound eyes effected a loss of entrainment.
Tryptamine Oxidation by Extracts of Pea Seedlings: Effect of Growth Retardant β-Hydroxyethylhydrazine
Authors: Reed Donald J.
Published: October 2006

β-Hydroxyethylhydrazine forces flowering of pineapple plants, possibly by reducing auxin concentration. A specific and sensitive assay showed that β-hydroxyethylhydrazine (3.3 × 10
-7
M
) inhibits noncompetitively and almost completely the oxidation of tryptamine to indoleacetaldehyde by extracts of pea-seedling (
Pisum sativum
L. var. Alaska). The relative rate of oxidation of putrescine to Δ
1
-pyrroline compared to that of tryptamine by these extracts and the inhibition of both reactions by β-hydroxyethylhydrazine suggest that diamine oxidase is inhibited. β-Hydroxyethylhydrazine is a potent inhibitor in vivo of animal diamine oxidase.
Sonar System of the Blind: Size Discrimination
Authors: Rice Charles E. , Feinstein Stephen H.
Published: October 2006

Measurements were made of the ability of four blind subjects to use echoes to discriminate between objects of different sizes placed in front of them. Threshold estimates indicate that objects with area ratios as low as 1.07/1 could be discriminated.
Carbonaceous Rocks of the Soudan Iron Formation (Early Precambrian)
Authors: Cloud Preston E. , Gruner John W. , Hagen Hannelore
Published: October 2006

Carbon-rich rocks more than 2.7 billion years old, from the Soudan Iron Formation of northeastern Minnesota, contain pyrite balls in which are found microstructures of possible biologic origin. The C
13
/C
12
and S
34
/S
32
ratios and minor element composition of this rock are consistent with such an interpretation. Hydrocarbons of presumed vital origin are also present, although it is not certain that they are endemic to the rock.
Attenuation of Aversive Properties of Peripheral Shock by Hypothalamic Stimulation
Authors: Cox Verne C. , Valenstein Elliot S.
Published: October 2006

Clinical reports of alleviation of pain with positive brain stimulation were investigated experimentally. Rats in a two-compartment testing chamber sought out hypothalamic stimulation and escaped from aversive foot shock delivered through a grid-scrambling device. Animals also sought out paired hypothalamic stimulation and foot shock. Control experiments demonstrating that animals did not discriminate between hypothalamic stimulation and paired hypothalamic stimulation and foot shock supported the view that hypothalamic stimulation attenuates the aversive properties of foot shock.
Absence of Martian Radiation Belts and Implications Thereof
Authors: Van Allen J. A. , Frank L. A. , Krimigis S. M. , Hills H. K.
Published: October 2006

A system of sensitive particle detectors on Mariner IV showed the presence of electrons of energy (
E
e
) greater than 40 kiloelectron volts out to a radial distance of 165,000 kilometers in the morning fringe of the earth's magnetosphere but failed to detect any such electrons during the close encounter with Mars on 14-15 July 1965, at the time when the minimum areocentric radial distance was 13,200 kilometers. This result can mean that the ratio of the magnetic dipole moment of Mars to that of the earth (
M
M
/
M
E
) is surely less than 0.001 and probably is less than 0.0005. The corresponding upper limits on the equatorial magnetic field at the surface of Mars are 200 and 100 gammas, respectively. It appears possible that the solar wind interacts directly with the Martian atmosphere.
Occultation Experiment: Results of the First Direct Measurement of Mars's Atmosphere and Ionosphere
Authors: Kliore Arvydas , Cain Dan L. , Levy Gerald S. , Eshleman Von R. , Fjeldbo Gunnar , Drake Frank D.
Published: October 2006

Changes in the frequency, phase, and amplitude of the Mariner IV radio signal, caused by passage through the atmosphere and ionosphere of Mars, were observed immediately before and after occultation by the planet. Preliminary analysis of these effects has yielded estimates of the refractivity and density of the atmosphere near the surface, the scale height in the atmosphere, and the electron density profile of the Martian ionosphere. The atmospheric density, temperature, and scale height are lower than previously predicted, as are the maximum density, temperature, scale height, and altitude of the ionosphere.
Fluorescent Contaminants from Plastic and Rubber Laboratory Equipment
Authors: Kordan Herbert A.
Published: October 2006

Plastic and rubber laboratory apparatus contains materials that are extractable with water, aqueous solutions, and nonaqueous solvents. These extractable substances fluoresce under ultraviolet light and were found as contaminants in nutrient solution used for growing excised lemon fruit tissue in vitro. The source of these fluorescent contaminants has been removed by using all-glass laboratory equipment.
Interferon-Dependent Tyrosine Phosphorylation of a Latent Cytoplasmic Transcription Factor
Authors: Schindler Chris , Shuai Ke , Prezioso Vincent R. , Darnell James E.
Published: October 2006

The interferon-α (IFN-α)-stimulated gene factor 3 (ISGF3), a transcriptional activator, contains three proteins, termed ISGF3α proteins, that reside in the cell cytoplasm until they are activated in response to IFN-α. Treatment of cells with IFN-α caused these three proteins to be phosphorylated on tyrosine and to translocate to the cell nucleus where they stimulate transcription through binding to IFN-α-stimulated response elements in DNA. IFN-γ, which activates transcription through a different receptor and different DNA binding sites, also caused tyrosine phosphorylation of one of these proteins. The ISGF3α proteins may be substrates for one or more kinases activated by ligand binding to the cell surface and may link occupation of a specific polypeptide receptor with activation of transcription of a set of specific genes.
A Wandering Enteropneust from the Abyssal Pacific, and the Distribution of "Spiral" Tracks on the Sea Floor
Authors: Bourne Donald W. , Heezen Bruce C.
Published: October 2006

Certain coiled tracks appear in photographs from the bottom of most oceans and are abundant in some regions. Enteropneusts are among the forms responsible for such tracks although, despite earlier evidence, they are rarely considered to be either active or abyssal.
Organ Weights in Primates and Other Mammals
Authors: Stahl Walter R.
Published: October 2006

In mammals the weight of the heart, kidney, lungs, and other organs can be related to total body weight through power laws (allometry). Weights of primate organs are analyzed by this technique. Allometric coefficients and size-independent organ-weight or body-form ratios may be used to compare primates, including humans, and other mammals.
Blood Oxygen and Ecology of Porpoises of Three Genera
Authors: Ridgway Sam H. , Johnston D. Gordon
Published: October 2006

Blood volumes, hemoglobin concentrations, packed-cell volumes, and heart weights were determined in three genera of porpoises which differ from one another in behavior and ecology. The estimate for the total blood-oxygen content of the highly active, deep-diving, pelagic species
Phocoenoides dalli
was almost three times greater than that for the coastal-dwelling species
Tursiops truncatus
, and about 70 percent greater than for the less active pelagic species,
Lagenorhynchus obliquidens
. Heart weights of
Phocoenoides dalli
were about 140 percent greater than in
Tursiops truncatus
and 55 percent greater than in
Lagenorhynchus obliquidens
.
Ammonium Micas: Possible Sources of Atmospheric Ammonia and Nitrogen
Authors: Eugster Hans P. , Munoz James
Published: October 2006

Ammonium muscovite, NH
4
Al
2
AlSi
3
O
10
(OH)
2
, and ammonium phlogopite, NH
4
Mg
3
AlSi
3
O
10
(OH)
2
, have been synthesized hydrothermally at gas pressures of 2 kilobars and temperatures between 550° and 730°C. Both micas are stable only in environments of high ammonia fugacity. Ammonia or nitrogen, or both, are released by thermal decomposition, cation exchange, or oxidation. The ammonia : nitrogen ratio in the gas depends primarily on the hydrogen fugacity and the temperature of the environment. Calculations show that, even in a predifferentiated Earth, nitrogen may have predominated. The total amount of nitrogen present on the surface of Earth could be accounted for by the decomposition of a layer of ammonium muscovite 170 meters thick.
Slant Perception and Shape Constancy in Infants
Authors: Bower T. G. R.
Published: October 2006

Three experiments investigated shape constancy in human infants between 50 and 60 days of age. The first showed that such infants possess some capacity for shape constancy. The second confirmed this finding and showed that the capacity is not attained by correlation of perceived projective shape with perceived orientation.
Lymphocystis Virus: Isolation and Propagation in Centrarchid Fish Cell Lines
Authors: Wolf Ken , Gravell Maneth , Malsberger Richard G.
Published: October 2006

A virus from fish with lymphocystis disease was isolated in fish cell cultures. Eleven serial transfers were made and the pathognomonic lymphocystis cells were produced in vitro in each transfer. Fish inoculated with 6th- and 9th-passage material developed the disease, and virus was reisolated from them.
Neurofibrils and the Nauta Method
Authors: Lund R. D. , Westrum L. E.
Published: October 2006

When the pretreatment stages are omitted, the Nauta method for degenerating axons stains neurofibrils. Under the electron microscope the stain is closely related to neurofilaments. When one uses the complete Nauta technique, the stain is specific for membrane structures.
Deep Scattering Layer Migration and Composition: Observations from a Diving Saucer
Authors: Barham Eric G.
Published: October 2006

The distribution of a myctophid fish and physonect siphonophores observed during dives in the Soucoupe off Baja California closely correlates with scattering layers recorded simultaneously with a 12-kcy/sec echo sounder. These organisms were observed while they were migrating vertically, and at their night and daytime levels. They are capable of rapid, extensive changes in depth.
Hydrodynamic Performance of Porpoises (
Stenella attenuata
)
Authors: Lang Thomas G. , Pryor Karen
Published: October 2006

Two specimens of
Stenella attenuata
, trained to chase a winch-towed lure, reached a top speed of 11.03 meters per second (21.4 knots) in 2.0 seconds. The maximum power output, occurring 1.5 seconds after the start, was calculated from measured values of acceleration and drag coefficient. The maximum power output per unit body weight was 50 percent greater than for human athletes. The measured drag coefficient, obtained from periods of coasting, was approximately the same as that of an equivalent rigid body with a near-turbulent boundary layer.
Multiple Sclerosis: Serum Factor Producing Reversible Alterations in Bioelectric Responses
Authors: Cerf Jean A. , Carels Guy
Published: October 2006

Serums obtained from patients during acute exacerbations of multiple sclerosis produce a reversible depression of polysynaptic reflex responses when applied to the isolated spinal cord of the frog. Motoneuron discharges initiated by monosynaptic activation through an axosomatic spinal pathway are much less affected than reflex discharges. The active factor in serum appears to depend on the presence of complement.
Inhibition of Insulin Release by Norepinephrine in Man
Authors: Porte Daniel , Williams Robert H.
Published: October 2006

Normal subjects were given glucose (300 mg/ min) or tolbutamide (1 g, intravenously), alone and during intravenous infusions of norepinephrine (6 μg/ min). Immunoreactive insulin concentration was less than expected during the infusions of norepinephrine, but returned to higher values after the norepinephrine infusions. From these data it is concluded that norepinephrine inhibits the release of insulin from pancreatic beta cells.
Natural Human Antibodies to Gram-Negative Bacteria: Immunoglobulins G, A, and M
Authors: Cohen Irun R. , Norins Leslie C.
Published: October 2006

Significant amounts of immunoglobulins G and M, and a small amount of natural antibodies reactive with
Neisseria gonorrhoeae
and
Escherichia coli
, have been detected in human adult serums by immunofluorescent techniques. Umbilical cord serums also contained substantial immunoglobulin-G antibody but little or no M or A. These findings challenge the concept that natural antibodies reactive with Gram-negative bacteria are primarily of the immunoglobulin-M class.
Mutagenicity of Cycasin Aglycone (Methylazoxymethanol), a Naturally Occurring Carcinogen
Authors: Smith David W. E.
Published: October 2006

Methylazoxymethanol, a carcinogenic and hepatotoxic methylating agent prepared from cycad plants, has been found to be a good mutagen in
Salmonella typhimurium
.
Specialized Receptive Fields of the Cat's Retina
Authors: Stone Jonathan , Fabian Miriam
Published: October 2006

Three new types of receptive field have been found in the cat's retina. The responses of these fields to flashing lights and moving objects suggest that the manner in which they code visual information may be quite different from that of the center-surround fields described in previous studies. These "specialized" fields were all found in the area centralis. A definite functional difference, corresponding to the known anatomical difference, between this region and the rest of the retina, is suggested.
Angiotensin Regulates Release and Synthesis of Serotonin in Brain
Authors: Nahmod Victor E. , Finkielman Samuel , Benarroch Eduardo E. , Pirola Carlos J.
Published: October 2006

Angiotensin II released serotonin from neuron terminals and accelerated synthesis of the serotonin. This increase in synthesis depended on the activation of tryptophan hydroxylase. A biphasic effect was observed: at high doses the stimulatory effect depended on conversion of angiotensin II to angiotensin III. At low doses an inhibitory effect was found, possibly dependent on an angiotensin II metabolite. These actions represent a subtle regulation of the open-loop serotonin system.
Antibody Active Sites and Immunoglobulin Molecules
Authors: Singer S. J. , Doolittle Russell F.
Published: October 2006

In order to obtain detailed information about the relationship between structure and function in antibody molecules, a method called affinity labeling has been devised to attach chemical labels specifically to amino acid residues in the active sites of antibody molecules. With antibodies to three different haptens, highly specific labeling of the active sites has been achieved. Tyrosine residues on both heavy and light polypeptide chains have been labeled in a molar ratio close to 2:1, and labels on the two chains are equally specific to the active sites. Peptide fragmentation studies of the labeled chains of one antibody system have shown that: (i) within 25 amino acid residues of the labeled tyrosine on either chain, substantial chemical heterogeneity exists among different antibody molecules of the same specificity; and (ii) the labeled peptide fragments from both chains are very similar in physicochemical characteristics, including average size, heterogeneity, and unusual hydrophobicity.

These experimental results have led us to the view that a particular region of the heavy chain and a particular region of the light chain are utilized to construct the active sites of the three different antibodies, differences in specificity arising from chemical perturbations in these two regions. Correlated structural studies of affinity-labeled antibodies and of the homogeneous light chains (Bence Jones proteins) and heavy chains produced in multiple myeloma may permit the identification of these special active-site regions. The view that active sites of different specificity are chemical perturbations of a particular region of the antibody molecule has a possible close analogue in enzyme systems, particularly among the esterases.

The marked chemical similarities we have observed between the active site regions of heavy and light chains indicate to us that chemical homologies, but not identities, exist between the chains. This is reinforced by recently obtained amino acid sequence data which reveal homologies between the two chains near their carboxyl-terminals. These results indicate that the structural genes which code for the synthesis of heavy and light chains are related, presumably having arisen from some common ancestral gene during evolution. This conclusion strongly suggests that both heavy and light chains determine antibody specificity, and has important implications for the still-unknown mechanisms of antibody biosynthesis.
Dynamic Programming
Authors: Bellman Richard
Published: October 2006

Little has been done in the study of these intriguing questions, and I do not wish to give the impression that any extensive set of ideas exists that could be called a "theory." What is quite surprising, as far as the histories of science and philosophy are concerned, is that the major impetus for the fantastic growth of interest in brain processes, both psychological and physiological, has come from a device, a machine, the digital computer. In dealing with a human being and a human society, we enjoy the luxury of being irrational, illogical, inconsistent, and incomplete, and yet of coping. In operating a computer, we must meet the rigorous requirements for detailed instructions and absolute precision. If we understood the ability of the human mind to make effective decisions when confronted by complexity, uncertainty, and irrationality, then we could use computers a million times more effectively than we do. Recognition of this fact has been a motivation for the spurt of research in the field of neurophysiology.

The more we study the information-processing aspects of the mind, the more perplexed and impressed we become. It will be a very long time before we understand these processes sufficiently to reproduce them.

In any case, the mathematician sees hundreds and thousands of formidable new problems in dozens of blossoming areas, puzzles galore, and challenges to his heart's content. He may never resolve some of these, but he will never be bored. What more can he ask?
Circadian Rhythm in Pineal Tyrosine Hydroxylase
Authors: McGeer Edith G. , McGeer Patrick L.
Published: October 2006

Tyrosine hydroxylase is the rate-limiting enzyme in catecholamine synthesis. The rat pineal gland is richly innervated by sympathetic nerves from the superior cervical ganglia. The activity of tyrosine hydroxylase was measured in rat pineal gland at 4-hour intervals over a daily cycle of 12 hours of light (7 a.m. to 7 p.m.) and 12 hours of darkness. The results indicate a circadian rhythm with the maximum activity, at 11 p.m. to 3 a.m., about triple the low values observed at 3 p.m. The pattern is similar in phase to that previously reported for melatonin and hydroxyindole-
O
-methyl transferase activity.
Chemotaxis in Bacteria
Authors: Adler Julius
Published: October 2006

Motile
Escherichia coli
placed at one end of a capillary tube containing an energy source and oxygen migrate out into the tube in one or two bands, which are clearly visible to the naked eye and can also be demonstrated by photography, microscopy, and densitometry and by assaying for bacteria throughout the tube. The formation of two bands is not due to heterogeneity among the bacteria, since the bacteria in each band, when reused, will form two more bands.

If an anaerobically utilizable energy source such as galactose is present in excess over the oxygen, the first band consumes all the oxygen and a part of the sugar and the second band uses the residual sugar anaerobically. On the other hand, if oxygen is present in excess over the sugar, the first band oxidizes all the sugar and leaves behind unused oxygen, and the second band uses up the residual oxygen to oxidize an endogenous energy source.

The essence of the matter is that the bacteria create a gradient of oxygen or of an energy source, and then they move preferentially in the direction of the higher concentration of the chemical. As a consequence, bands of bacteria (or rings of bacteria in the case of agar plates) form and move out. These results show that
E. coli
is chemotactic toward oxygen and energy sources such as galactose, glucose, aspartic acid, threonine, or serine. The full repertoire of chemotactic responses by
E. coli
is no doubt greater than this, and a more complete list remains to be compiled.

The studies reported here demonstrate that chemotaxis allows bacteria to find that environment which provides them with the greatest supply of energy. It is clearly an advantage for bacteria to be able to carry out chemotaxis, since by this means they can avoid unfavorable conditions and seek optimum surroundings.

Finally, it is necessary to acknowledge the pioneering work of Englemann, Pfeffer, and the other late-19th-century biologists who discovered chemotaxis in bacteria, and to point out that the studies reported here fully confirm the earlier reports of Beijerinck and Sherris and his collaborators on a band of bacteria chemotactic toward oxygen. By using a chemically defined medium instead of a complex broth, it has been possible to study this band more closely and to demonstrate in addition the occurrence of a second band of bacteria chemotactic toward an energy source. Beijerinck did, in fact, sometimes observe a second band, but he did not offer an explanation for it.
Vitamin C-Induced Increase of Dermatan Sulfate in Cultured Hurler's Fibroblasts
Authors: Schafer Irwin A. , Sullivan Julia C. , Svejcar Jiri , Kofoed Jorge , Robertson William van B.
Published: October 2006

In fibroblasts taken from patients with Hurler's syndrome and grown in culture, dermatan sulfate constituted a larger percentage of the total sulfated glycosaminoglycans than it did in cultured fibroblasts from unaffected individuals. Moreover, the addition of ascorbic acid (vitamin C) to the culture medium markedly increased the concentration of dermatan sulfate in the Hurler's fibroblasts but not in the normal fibroblasts. The biochemical phenotype of the Hurler's cells persisted during 28 weeks of serial culture.
Stick-Slip as a Mechanism for Earthquakes
Authors: Brace W. F. , Byerlee J. D.
Published: October 2006

Stick-slip often accompanies frictional sliding in laboratory experiments with geologic materials. Shallow-focus earthquakes may represent stick-slip during sliding along old or newly formed faults in the earth. In such a situation, observed stress drops represent release of a small fraction of the stress supported by the rock surrounding the earthquake focus.
Malathion Degradation by
Trichoderma viride
and a
Pseudomonas
Species
Authors: Matsumura F. , Boush G. M.
Published: October 2006

Malathion was found to be metabolized quickly by a soil fungus,
Trichoderma viride
, and a bacterium,
Pseudomonas
sp., which were originally found in soils from northern Ohio that had been sprayed heavily with insecticides. Results of a survey of the breakdown capabilities of 16 variants of
T. viride
revealed that certain colonies from this species had a very marked ability to breakdown malathion through the action of a carboxylesterase(s). The enzymes can be made soluble by preparing the acetone powder suspension.
"Dream Deprivation": Effects on Dream Content
Authors: Pivik Terry , Foulkes David
Published: October 2006

Dream content elicited following the selective deprivation of rapid-eye-movement sleep was intensified compared to that elicited under nondeprivation conditions. This effect was observed both for repressers and for sensitizers, but was significant only for repressers. On nondeprivation nights, the dream periods of sensitizers were shorter and their dreams more intense than those of repressers.
Airborne Geophysical Study in the Pensacola Mountains of Antarctica
Authors: Behrendt John C. , Meister Laurent , Henderson John R.
Published: October 2006

A seismic reflection, gravity, and aeromagnetic reconnaissance was made in the Pensacola Mountains, Antarctica, during the 1965-66 austral summer. Prominent ice streams located between the Neptune and Patuxent Ranges and east of the Forrestal Range overlie channels in the rock surface 2000 meters below sea level which are probably of glacial origin. Seismic reflections show that the Filchner Ice Shelf is 1270 meters thick near its southern margin. Along the boundary between West and East Antarctica, Bouguer anomalies decrease from +60 milligals in West Antarctica to —80 milligals in East Antarctica. An abrupt change in crustal structure across this boundary is required to explain the 2 milligals per kilometer gradient. This may indicate a fault extending through the crust into the mantle. Aeromagnetic profiles delineate anomalies up to 1800 γ associated with the basic stratiform intrusion which comprises the Dufek and Forrestal ranges. A probable minimum area of 9500 square kilometers is calculated for the intrusive body on the basis of the magnetic anomalies, making it one of the largest bodies of its type. The extension of this magnetic anomaly across a fault forming the north border of the Pensacola Mountains probably precludes transcurrent movement.
Minchinia nelsoni
n. sp. (Haplosporida, Haplosporidiidae): Causative Agent of the Delaware Bay Oyster Epizoötic
Authors: Haskin Harold H. , Stauber Leslie A. , Mackin John A.
Published: October 2006

Since 1957, oyster popuulations of the Middle Atlantic coast have been ravaged by a new sporozoan parasite that has been called "MSX." This parasite is identified as a new species of
Minchinia
that invades oysters through epithelial tissues of gill, palp, water tubes, and, occasionally, of the digestive tract. Multinucleate plasmodia are recognized in fresh and fixed preparations.
A Braille-Reading Machine
Authors: Grunwald Arnold P.
Published: October 2006

A new system for publishing and presenting Braille text is delineated. The system requires a new device for actual "reading." Experiments to determine reader preference and acceptance of the device are presented, and performance criteria on the device are listed.
Continental Margin of Western Europe: Slope Progradation and Erosion
Authors: Curray J. R. , Moore D. G. , Belderson R. H. , Stride A. H.
Published: October 2006

Reflection profiling of the continental margin off western Europe shows seaward-dipping continental-slope deposits that have been dissected by submarine canyons west of the English Channel. These records refute previous interpretation of structural benches of older, nearly horizontal strata outcropping on the slope face.
Visual and Nonvisual Auditory Systems in Mammals
Authors: Harrison J. M. , Irving R.
Published: October 2006

Examination of the structural organization of the auditory system of the brain stem shows that the system is composed of a number of separate ascending pathways. This suggests that there may be at least two auditory systems, analogous to the rod and cone pathways in vision. We examined this possibility by investigating the variation in relative size of the medial and lateral superior olivary nuclei in a number of different mammalian species.

The lateral superior olive is present in the hedgehog (an insectivore), cat (a carnivore), and squirrel monkey (a primate), but the medial superior olive is absent in the hedgehog. In a group of animals of the same taxonomic order (rodents) the lateral superior olive was present in all species examined, but the medial superior olive was almost wholly absent in the mouse and very prominent in the chinchilla and guinea pig. The absence of the medial superior olive in some animals is surprising because recent anatomical and physiological work has implicated the nucleus in auditory localization. Because of this implication, the medial and lateral olivary nuclei were examined in three species of bat and one dolphin, all echolocating animals. The medial superior olive was absent in these animals, and the lateral superior olive was prominent.

These observations support the idea that the medial and lateral superior olives are nuclei on two different ascending auditory systems. It was also noted that the medial superior olive was always well developed in animals with well-developed eyes, and this suggested that the nucleus is in some way related to the visual system. We examined this idea by studying the relation between the numbers of cells in the medial superior olive and in the nucleus of the 6th cranial nerve (one of the motor nuclei concerned with eye movement) in a number of mammalian species. An approximately linear function was found between the sizes of the 6th nucleus and of the medial superior olive in three primates with cone-cell retinas (squirrel monkey, man, and macaque) and four rodents with rod-cell retinas (mouse, rat, guinea pig, and chinchilla). The cell numbers for the ground squirrel (a rodent with cone-cell retina) fitted an extension of the primate curve, and the cell numbers for the cat (in whose retina rods predominate) fitted an extension of the rodent curve. Thus, it is clear that the medial superior olive is related to the visual system, and that it is present in animals with cone-cell fovea and retina (diurnal animals) and animals with rod-cell retina (that is, nocturnal animals) having good vision. In nonvisual nocturnal animals the nucleus is small or absent. The medial superior olive is probably not concerned with auditory localization in the psychophysical sense but is probably concerned with the movement of head and eyes in the direction of a sound in space. Localization in the psychophysical sense and fine auditory discrimination probably depend upon the ascending pathway which includes the lateral superior olive.
Adenovirus Multiplication: Inhibition by Methisazone
Authors: Bauer D. J. , Apostolov K.
Published: October 2006

Methisazone (5 to 40 μM) inhibited the multiplication of types 3, 7, 9, 11, 14, 16, 17, 21, and 28 adenovirus; SV15 (a simian adenovirus) was also inhibited. A study of adenovirus 11 under single-cycle conditions showed that multiplication of the virus was completely inhibited by 30 μM methisazone when addition of the compound was delayed until 13 hours after infection. A survey showed that the structure-activity relations of the action of methisazone against adenoviruses and pox viruses are similar.
Paraproteinemia and Reticulum Cell Sarcoma in an Inbred Mouse Strain
Authors: Wanebo Harold J. , Gallmeier Walter M. , Boyse Edward A. , Old Lloyd J.
Published: October 2006

Mice of the inbred SJL/J strain have a high incidence of a proliferative disease affecting several cell types, including reticulum cells and plasma cells, which is frequently accompanied by γ
1
and γ
2
paraproteinemia. In only some instances can serially transplantable lines of neoplastic cells be obtained; these are reticulum cell sarcomas. Mice with transplanted reticulum cell sarcomas do not have paraproteinemia and may develop profound hypogammaglobulinemia. The disease may be viewed as an abnormal proliferation of reticulum cells which differentiate into plasma cells with consequent paraproteinemia; the subsequent emergence of transplantable reticulum cell sarcoma appears as an end stage in which this capacity to differentiate is lost.
Cilia Regeneration in the Sea Urchin Embryo: Evidence for a Pool of Ciliary Proteins
Authors: Auclair Walter , Siegel Barry W.
Published: October 2006

Late gastrulae of
Paracentrotus lividus
regenerated cilia after being deciliated in hypertonic sea water. Regeneration was not affected by actinomycin D or puromycin. Actinomycin D also did not affect ciliary protein synthesis during regeneration, although overall embryonic synthesis was depressed. Puromycin inhibited both total embryonic and ciliary protein synthesis. The data indicate that ciliary protein synthesis is controlled by a stable template and that the regenerating cilia are formed from a pool of ciliary proteins. It is suggested that the proteins of the mitotic apparatus and of the cilia may be related.
Western Equine Encephalitis Virus in Saskatchewan Garter Snakes and Leopard Frogs
Authors: Burton Althea N. , McLintock J. , Rempel J. G.
Published: October 2006

Western equine encephalitis virus was isolated from two naturally infected snakes on first bleeding and from seven others at subsequent bleedings, both with and without preliminary chilling. One snake, with neither detectable virus nor serum neutralizing antibodies when first bled, developed viremia later. Viremia in garter snakes has a cyclic rhythm independent of the temperature of the environment. Virus was isolated from 6 frogs, and 50 out of 179 had detectable serum neutralizing antibodies. Infections with this virus are widely distributed in garter snakes and leopard frogs in the agricultural area of Saskatchewan.
Stratigraphic Sections, Bedding Sequences, and Random Processes
Authors: Carr Donald D. , Horowitz Alan , Hrabar S. V. , Ridge Kathleen F. , Rooney Rosalia , Straw W. Thomas , Webb William , Potter Paul Edwin
Published: October 2006

Both dependent and independent random processes can be used to study and synthesize stratigraphic sections and bedding sequences. Synthetic stratigraphic sections can be modeled to fit any geologic problem with a good correspondence between the synthetic and actual stratigraphic sections. To synthesize a sedimentary sequence, one needs only a transition procedure to go from one lithology or bedding type to another, and frequency distributions of thickness for the various lithologies. A sedimentation process with a "memory" is termed Markovian; if the past has no influence on either present or future sedimentation, it is called an independent trials process.
Rapid and Marked Inhibition of Rat-Liver RNA Polymerase by Aflatoxin B
1
Authors: Gelboin H. V. , Wortham J. S. , Wilson R. G. , Friedman Marvin , Wogan G. N.
Published: October 2006

From 15 minutes to 2 hours after the administration of aflatoxin B
1
in vivo there is a 35- to 70-percent inhibition of DNA-directed RNA synthesis. The inhibition was reversed 12 and 24 hours later.
Cystinuria: Genetic Heterogeneity and Allelism
Authors: Rosenberg Leon E.
Published: October 2006

Studies of four stone-forming cystinuric subjects from three unrelated pedigrees indicated that each was heterozygous for two of the three described mutant genes producing cystinuria (I, II, III). Their genotypes were I-II, II-III, I-III, and I-III, respectively. These doubly heterozygous patients were phenotypically indistinguishable from cystinuric homozygotes of genotype I-I, II-II, or III-III. The data provide the first direct evidence that all of the known mutations responsible for the genetic heterogeneity in cystinuria are allelic.
Pupil Diameter and Load on Memory
Authors: Kahneman Daniel , Beatty Jackson
Published: October 2006

During a short-term memory task, pupil diameter is a measure of the amount of material which is under active processing at any time. The pupil dilates as the material is presented and constricts during report. The rate of change of these functions is related to task difficulty.
Garnet Zoning: An Interpretation Based on the Rayleigh Fractionation Model
Authors: Hollister Lincoln S.
Published: October 2006

Manganese zoning in almandine garnet is interpreted by the use of calculations based on the Rayleigh fractionation model. A close similarity of a measured manganese zoning profile and a calculated profile indicates that the assumptions used in the calculations are good. These assumptions are: complete removal of garnet from a homogeneous reservoir as the garnet crystallizes, and a nearly constant manganese fractionation factor between garnet and reservoir.
Immunologic Maturation
in utero
: Kinetics of the Primary Antibody Response in the Fetal Lamb
Authors: Silverstein Arthur M. , Parshall Charles J. , Uhr Jonathan W.
Published: October 2006

The kinetics of the primary antibody response to bacteriophage φX174 have been studied in the fetal lamb
in utero
after permanent indwelling catheterization of the fetal blood vessels. The initial antibody response by the developing fetus to this form of antigenic stimulus is comparable to that found in adult animals and shows none of the characteristics of the immature immunologic response that have generally been ascribed to fetal and neonatal animals.
Isolation of Two Genes That Encode Subunits of the Yeast Transcription Factor IIA
Authors: Ranish Jeffrey A. , Lane William S. , Hahn Steven
Published: October 2006

The yeast transcription factor IIA (TFIIA), a component of the basal transcription machinery of RNA polymerase II and implicated in vitro in regulation of basal transcription, is composed of two subunits of 32 and 13.5 kilodaltons. The genes that encode these subunits, termed
TOA1
and
TOA2
, respectively, were cloned. Neither gene shares obvious sequence similarity with the other or with any other previously identified genes. The recombinant factor bound to a TATA binding protein-DNA complex and complemented yeast and mammalian in vitro transcription systems depleted of TFIIA. Both the
TOA1
and
TOA2
genes are essential for growth of yeast.
Effect of Sodium Salicylate on the Human Heat Shock Response
Authors: Jurivich Donald A. , Sistonen Lea , Kroes Roger A. , Morimoto Richard I.
Published: October 2006

Sodium salicylate, an anti-inflammatory agent, was examined for its effects on the heat shock response in cultured human cells. Salicylate activation of DNA binding by the heat shock transcription factor (HSF) was comparable to activation attained during heat shock. However, sodium salicylate did not induce heat shock gene transcription even though the HSF was bound in vivo to the heat shock elements upstream of the heat shock protein 70 (Hsp 70) gene. These results reveal that activation of the heat shock transcriptional response is a multistep process. Modulation of extracellular pH augments sensitivity to salicylate-induced activation of HSF.
Cognitive and Motor Impairments Associated with SIV Infection in Rhesus Monkeys
Authors: Murray Elisabeth A. , Rausch Dianne M. , Lendvay Judit , Sharer Leroy R. , Eiden Lee E.
Published: October 2006

Cognitive and motor deficits are now recognized as significant clinical features of infection with the human immunodeficiency virus (HIV). Juvenile rhesus macaques infected with simian immunodeficiency virus (SIV) were found to exhibit cognitive and motor deficits characteristic of HIV infection. Impairment on a motor skill task was the most reliable indicator of infection. Various cognitive impairments were also evident. These deficits were related to SIV infection of the brain but not to inflammatory lesions at a particular locus. The results suggest that the SIV-infected rhesus macaque is a valuable model for understanding the cause of HIV-associated central nervous system dysfunction and for developing a treatment.
Extension of Northeastern-Pacific Fracture Zones
Authors: Menard H. W.
Published: October 2006

The great fracture zones of the northeastern Pacific extend into the central Pacific. At a relatively constant distance of 4500 to 4900 kilometers west of the crest of the East Pacific Rise and of its projection through North America, the typically straight and simple fracture zones branch and become more complex. However, the Clipperton fracture zone, including one branch, follows a great circle for almost 10,000 kilometers, a quarter of Earth's circumference.
Biotite Flakes: Alteration by Chemical and Biological Treatment
Authors: Boyle J. R. , Voigt G. K. , Sawhney B. L.
Published: October 2006

Biotite alteration under acid conditions proceeds differently from the generally accepted pathway of transformation to vermiculite in which hydrated cations cause interlayer expansion, resulting in a dark-colored peripheral band on mica particles. Acid solutions of synthetic or biologic origin remove octahedral ions, leaving a fragile matrix of amorphous material.
Nutrient Cycling
Authors: Bormann F. H. , Likens G. E.
Published: October 2006

The small-watershed approach to problems of nutrient cycling has these advantages. (i) The small watershed is a natural unit of suitable size for intensive study of nutrient cycling at the ecosystem level. (ii) It provides a means of reducing to a minimum, or virtually eliminating, the effect of the difficult-to-measure variables of geologic input and nutrient losses in deep seepage. Control of these variables makes possible accurate measurement of nutrient input and output (erosion) and therefore establishes the relationship of the smaller ecosystem to the larger biospheric cycles. (iii) The small-watershed approach provides a method whereby such important parameters as nutrient release from minerals (weathering) and annual nutrient budgets may be calculated. (iv) It provides a means of studying the interrelationships between the biota and the hydrologic cycle, various nutrient cycles, and energy flow in a single system. (v) Finally, with the small-watershed system we can test the effect of various land-management practices or environmental pollutants on nutrient cycling in natural systems.
Early Receptor Potential: Photoreversible Charge Displacement in Rhodopsin
Authors: Cone Richard A.
Published: October 2006

When the eye is illuminated by an intense flash, the visual pigment rhodopsin begins to pass rapidly through a series of intermediate states, eventually becoming bleached. If a second flash is delivered during the lifetimes of these intermediates the rhodopsin can be photoregenerated. A fast electrical response of the visual receptors, the early receptor potential, is elicited by the first flash. A similar response is elicited by the second flash, but the polarity of this response is reversed. Moreover, this response can be separated into three components, each arising from the action of light on a different intermediate. It is likely that all these fast responses, including the early receptor potential, arise from charge displacements in the visual-pigment molecule.
America's Children: Economic Perspectives and Policy Options
Authors: Fuchs Victor R. , Reklis Diane M.
Published: October 2006

American children are worse off than those in the previous generation in several important dimensions of mental, physical, and emotional well-being. During the 1960s cultural changes adversely affected children while their material condition improved substantially. By contrast, material conditions deteriorated in the 1980s, especially among children at the lower end of the income distribution. Public policies to improve the material condition of children require a transfer of resources from households that do not have children to those that do. Government programs such as tax credits and child allowances are more efficient and equitable than employer-mandated programs.
Identification of the Integrin VLA-2 as a Receptor for Echovirus 1
Authors: Bergelson Jeffrey M. , Shepley Michael P. , Chan Bosco M. C. , Hemler Martin E. , Finberg Robert W.
Published: October 2006

Cell surface receptors for echovirus, a common human pathogen, were identified with monoclonal antibodies that protected susceptible cells from infection with echovirus 1. These monoclonal antibodies, which prevented virus attachment to specific receptor sites, recognized the α and β subunits of the integrin VLA-2 (α
2
β
1
), a receptor for collagen and laminin. RD rhabdomyosarcoma cells expressed little VLA-2, did not bind to
35
S-labeled virus, and resisted infection until transfected with complementary DNA encoding the α
2
subunit of VLA-2. Thus, integrins, adhesion receptors important in interactions between cells and with the extracellular matrix, can mediate virus attachment and infection.