bluuebunny/crossref_metadata_2025 huggingface dataset:
The Possible Role of Histones in the Mechanism of Chromosomal G Banding
Authors: Brown Ronald L. , Pathak S. , Hsu T. C.
Published: October 2006

Cytochemical data are presented to show that the histone fractions f1 and f2a are involved in the induction of chromosomal G bands, whereas the f2b and f3 fractions are not involved. Removal of the f1 and f2a fractions probably occurs during fixation and is necessary for the induction of G bands.
Strange Females Increase Plasma Testosterone Levels in Male Mice
Authors: Macrides F. , Bartke A. , Dalterio S.
Published: October 2006

Male house mice paired with a normal female for 1 week do not have higher plasma testosterone levels than do males that remain in all-male groups, but paired males have markedly elevated testosterone levels 30 to 60 minutes after the resident female is replaced by another female. Elevation of testosterone levels in these males is similar to that in isolated males paired with a female, does not depend on copulation with the strange female, occurs under housing conditions that permit continuous exposure to the odors of other females and males, and does not occur when the resident female is replaced by another male for 30 to 60 minutes. The elevation thus appears to be a specific endocrine response to an encounter with a strange female. These results, along with previous findings suggesting that strange males affect endocrine function in females, indicate that bisexual encounters are likely to produce endocrine changes in members of both sexes.
Regulation of Technological Activities: A New Approach
Authors: Ramo Simon
Published: October 2006

Efforts to regulate technological activities have led to confusing and inconsistent government actions, delays in realizing the benefits from scientific advances, huge financial burdens, and doubtful protection. In the absence of a clear decision-making authority on technological issues, appeal from regulations is frequently sought in the courts. A new approach to regulation is proposed in which the tasks of investigating a technological activity and of making decisions are separated. The former would be carried out by an investigatory agency charged with and enabled to determine the negative aspects of the technological activity, the latter by politically appointed decision boards. The boards would consider the negative evidence presented by the investigatory agency and balance it against the benefits of the proposed activity.
Daily Rhythm in Human Urinary Melatonin
Authors: Lynch H. J. , Wurtman R. J. , Moskowitz M. A. , Archer M. C. , Ho M. H.
Published: October 2006

The melatonin in urine samples from six healthy adult volunteers was concentrated on Amberlite XAD-2 resin, eluted with organic solvents, and quantitated by use of a bioassay technique (the dermal melanophore response of larval anurans to melatonin in their bathing medium). The melatonin content of samples collected between 11 p.m. and 7 a.m. was, in each case, several times higher than that of samples collected between 7 a.m. and 3 p.m. or between 3 p.m. and 11 p.m.
Molluscan Gastrin: Concentration and Molecular Forms
Authors: Straus Eugene , Yalow Rosalyn S. , Gainer Harold
Published: October 2006

Blood and gastrointestinal tissues of the sea hare
Aplysia californica
and the land snail
Otala lactea
contain immunoreactive gastrin in heterogeneous forms similar to those of mammals. The observation that blood concentrations in terms of a porcine gastrin standard are comparable to those of pig, man, and dog suggests significant homology between the structures of molluscan and mammalian gastrins.
Prostaglandin F
2α
Production by the Brain During Estrogen-Induced Secretion of Luteinizing Hormone
Authors: Roberts John S. , McCracken John A.
Published: October 2006

The arteriovenous difference in the concentration of prostaglandin F
2α
(PGF
2α
) across the brain of the anestrous sheep was measured before and during the induction of luteinizing hormone secretion with 17β-estradiol. The results indicate that (i) the brain in vivo is a significant source of PGF
2α
, (ii) the release of PGF
2α
from the brain occurs in pulses with a circhoral rhythm, and (iii) the process through which estrogen exerts its negative and positive feedback effects on luteinizing hormone secretion may involve amplitude modulation of PGF
2α
output from the brain.
Locus of Short-Term Visual Storage
Authors: Sakitt Barbara
Published: October 2006

A rod monochromat can preserve visual information in iconic memory even when the initial stimulus is invisible to the subject. Since the initial invisibility is due to rod saturation, it can be shown that all the information must have been stored inside the photoreceptors. Because the spectral sensitivity for producing icons in normal subjects is that of the rods, the conclusion is that in normal subjects, under ordinary viewing conditions, the photoreceptors are the primary store for iconic memory.
Infrared Transmittance as an Alternative Thermal Strategy in the Desert Beetle
Onymacris plana
Authors: Henwood Kenneth
Published: October 2006

Elevated elytral transmittance to shortwave infrared radiation is used by the black diurnal desert beetle
Onymacris plana
to increase heat gain at the beginning and end of the day. Near-infrared transmittance increases the percentage of radiation absorptance at times of low sun angle as a result of the relatively greater attenuation of visible to shortwave infrared radiation by longer atmospheric path lengths. Visible and ultraviolet radiation are absorbed by the insulated elytra, facilitating heat loss by convection at times of high sun angle.
Dimethyl Disulfide: An Attractant Pheromone in Hamster Vaginal Secretion
Authors: Singer Alan G. , Agosta William C. , O'Connell Robert J. , Pfaffmann Carl , Bowen David V. , Field Frank H.
Published: October 2006

Dimethyl disulfide, isolated from estrous hamster vaginal secretion and identified by gas chromatography-mass spectrometry, is an attractant for male hamsters.
Rapid Discrimination of Rewarding Nutrient by the Upper Gastrointestinal Tract
Authors: Puerto Amadeo , Deutsch J. A. , Mólina F. , Roll Philip L.
Published: October 2006

When certain nutrients are injected into the stomachs of rats that are drinking one of two samples of nonnutrient, flavored water, the rats will (within a 10-minute session) choose the flavor paired with the nutrient. Such rewarding effects are obtained with predigested milk but not with similarly treated glucose or fresh milk. The results suggest the presence of rapidly acting, specialized, nutrient receptors in the upper gastrointestinal tract.
DNA Structure in Sheared and Unsheared Chromatin
Authors: Nicolini C. , Baserga R. , Kendall F.
Published: October 2006

Shearing chromatin, by either sonication or vortex homogenization, introduces significant structural artifacts. These may be detected by the anomalously large increase in the number of ethidium bromide binding sites and the large alteration of the circular dichroism spectra of chromatin. Structural alterations are also suggested by the disappearance of differential light scattering after shearing.
Self-Stimulation of the Brain
Authors: Olds James
Published: October 2006

My conclusions are these: (i) The cells which mediate primary rewarding effects are located in a midline system running from the midbrain through the hypothalamus and midline thalamus and into the subcortical and cortical groups of the rhinencephalon. (ii) The cell groups which mediate primary rewarding effects are different from those which mediate primary punishing effects. (iii) Despite this relative independence, there are, undoubtedly, relationships of mutual inhibition existing between these two systems. Rewards do, among other things, tend to reduce sensitivity to pain, and punishments do tend to reduce rewarding effects. (iv) These primary reward systems of the brain are subdivided into specific drive-reward subsystems mediating the specific drives such as hunger and sex. (v) Because there are also subsystems of this set of rewarding structures sensitive to different chemical effects, it is reasonable to hope that eventually it will be possible to control the reward systems pharmacologically in cases where behavior disorders seem to result from deficits or surfeits of positive motivation.
Gnathotrichus sulcatus
: Synergistic Response to Enantiomers of the Aggregation Pheromone Sulcatol
Authors: Borden J. H. , Chong L. , McLean J. A. , Slessor K. N. , Mori K.
Published: October 2006

In laboratory and field bioassays,
Gnathotrichus sulcatus
responded to sulcatol (6-methyl-5-hepten-2-ol) only when both enantiomers were present. Response was greater to racemic sulcatol than to a mixture (65 : 35) of S-(+) and R-(-) enantiomers, the naturally occurring isomeric ratio. Enantiomer-specific active sites on receptor proteins in the same or different cells are implicated.
New Type Sedative and Soporific Drug
Authors: Cronheim Georg , Gourzis James T. , Toekes I. M.
Published: October 2006

Trimethoxybenzoyl-glycine-diethylamide induced in dogs and cats normal sleep without preceding ataxia. A five- to ten-fold increase of the soporific dose resulted in restlessness and disorientation instead of sleep. In man, oral doses of 500 to 1500 mg caused sedation or drowsiness, or both, in half the cases. No spindling or drug-induced artifacts were found in electroencephalographic recordings.
Fusion Contour for Intermittent Photic Stimuli of Alternating Duration
Authors: Brown Charles R. , Forsyth D. M.
Published: October 2006

It is generally thought that fusion of intermittent photic stimuli occurs when the duration between successive pulses of light is reduced to a certain value, this value being a function of the illumination and viewing conditions. The findings described in this report show that fusion is determined not only by the duration between successive stimuli but also by the temporal pattern of successive stimuli.
Age of Sex-Determining Mechanisms in Vertebrates
Authors: Witschi Emil
Published: October 2006

Certain characteristic patterns of physiologic sex determination are not causally linked with types of genic and chromosomal constitution (XX-XY or ZW-ZZ). The observed widespread but not universal parallelism in the distribution of genetic and physiologic patterns among vertebrate groups expresses genealogic relationship. On the basis of this interpretation one may estimate the approximate evolutionary age of the mechanism of genetic sex determination. It is concluded that in all tetrapod vertebrates these mechanisms originated during the Jurassic period. Environmental conditions seem to affect the progress of this evolution.
Morphologic Observations on Trachoma Virus in Cell Cultures
Authors: Gordon Francis B. , Quan Alice L. , Trimmer Roy W.
Published: October 2006

When cultures of cells derived from the entoderm of the chick embryo were infected with trachoma virus, cytoplasmic inclusion bodies composed of viral particles were easily demonstrated. The inclusions are similar to those found in stained smears from trachomatous eyes and they developed in a sequence characteristic for this group of viruses. This method of culture appears to offer a valuable additional tool for study of the trachoma agent.
Temperature Fluctuations Accompanying Water Movement through Porous Media
Authors: Anderson Dwayne M. , Linville A.
Published: October 2006

Temperature measurements were made at localized sites in bentonite, kaolinite, and small glass beads during infiltration. The temperature of the medium was observed to rise gradually and then to drop sharply as the infiltrating water approached and reached the measurement site. Temperature fluctuations were observed to be about 9°C for bentonite, 4°C for kaolinite, and 0.1°C for the glass beads.
Subfractionation of Human Serum Enzymes
Authors: Dubbs Clyde A. , Vivonia Charlotte , Hilburn Jean M.
Published: October 2006

Evidence is given for the subfractionation by starch gel electrophoresis of human serum cholinesterase, aromatic esterase, and acid phosphatase. These subfractions and unfractionated leucine aminopeptidase are localized with respect to the protein zones of the Smithies starch gel pattern.
In vitro Studies of Single Isolated Beating Heart Cells
Authors: Harary Isaac , Farley Barbara
Published: October 2006

Rat heart cells, separated by trypsin treatment and grown attached to glass in a liquid medium, exhibit periodic contractions similar to a whole beating heart. The rate of beating, which is up to 150 beats per minute, is affected by cardiac drugs and by metabolic substrates and inhibitors.
Dehydrogenase Activities in Dystrophic Mice
Authors: McCaman M. W.
Published: October 2006

The levels of activity of glucose-6-phosphate dehydrogenase, isocitric dehydrogenase, glutathione reductase, lactic dehydrogenase, and α-glycerophosphate dehydrogenase have been studied in the gastrocnemius muscle of mice with "dystrophia muscularis." The activity of enzymes requiring triphosphopyridine nucleotide as a cofactor is increased relative to the control littermates, whereas the activity of those enzymes requiring diphosphopyridine nucleotide is decreased.
Attentive, Affective, and Adaptive Behavior in the Cat
Authors: Sprague James M. , Chambers William W. , Stellar Eliot
Published: October 2006

Lesions of the lateral portion of the upper midbrain, involving medial, lateral, spinal, and trigeminal lemnisci primarily, result in a consistent syndrome of symptoms in the cat. (i) There is a marked
sensory deficit,
characterized mainly by sensory inattention and poor localization in the tactile, proprioceptive, auditory, gustatory, and nociceptive modalities, where direct pathways are interrupted. Similar defects appear in vision and olfaction where no known direct or primary paths are interrupted. (ii) These cats are characterized by a
lack of affect,
showing little or no defensive and aggressive reaction to noxious and aversive situations and no response to pleasurable stimulation or solicitation of affection or petting. The animals are mute, lack facial expression, and show minimal autonomic responses. (iii) They show a
hyperexploratory activity
characterized by incessant, stereotyped wandering, sniffing, and visual searching, as though hallucinating. This behavior appears to be centrally directed and is very difficult to interrupt with environmental stimuli. (iv) They also demonstrate
exaggerated oral activities:
they snap in response to tactile stimulation of the lips, seizing and swallowing small objects even if inedible; they overeat; they hold objects too large to swallow (a mouse, a catnip ball) firmly clamped in the mouth for long periods of time; they mount and seize other animals (rat, cat, dog, monkey) by the back or the neck; they lick and chew the hair and skin of the back or tail incessantly when confined in a cage.

In interpreting these results we emphasize the view that the syndrome is due chiefly to the extensive, specific, sensory deprivation produced by interruption of the lemnisci at the rostral midbrain. The relation of these findings to the effects of sensory isolation in man and animals, to the effects of midbrain lesions and neodecortication, to parietal lobe syndrome in primates, and to the behavior of autistic children is discussed. It is our belief, from these studies, that the symptoms produced by interruption of the lemnisci, characterized by a high degree of somatotopic and modality localization, are due to a loss of patterned sensory input to the forebrain, particularly to the neocortex and to the rostral midbrain. Without a patterned afferent input to the forebrain via the lemnisci, the remaining portions of the central nervous system, which include a virtually intact reticular formation, seem incapable of elaborating a large part of the animal's repertoire of adaptive behavior.
Effect of Strychnine upon the Electrical Activity of an Isolated Nerve Cell
Authors: Washizu Yoshiaki , Bonewell George W. , Terzuolo Carlo A.
Published: October 2006

The effect of strychnine upon the electrical activity recorded from the axon and the soma of an isolated nerve cell (the nonadapting stretch receptor cell of the crayfish) was studied. Protracted exposure of the soma of the cell to strychnine prolongs the duration of the intracellulary recorded action potential, as has been described in other excitable tissues treated with quaternary ammonium ions. During the plateau in the falling phase of the soma spike, the axon is usually firing repetitively. The stimulation of the inhibitory fiber produces a premature termination of the prolonged spike.
Gamma Globulin (Gm group) Heterogeneity in Chimpanzees
Authors: Boyer Samuel H. , Young William J.
Published: October 2006

The serum gamma globulin (Gm) serological system was examined in 24 chimpanzees. Five Gm a, Gm b, and Gm x phenotypes, including Gm (a—b—x—), were observed. Phenotype did not appear to be related to serum gamma globulin concentration. The presence of the Gm system in apes suggests that this polymorphism in man is balanced and ancient.
Uterotrophic Action of the Insecticide Methoxychlor
Authors: Tullner William W.
Published: October 2006

Dusting of rats and mice, as well as oral treatment with the insecticide methoxychlor, produced uterine weight increase in these rodents. Ablation of the ovaries, adrenals, or pituitary did not alter this effect, thus indicating a direct trophic action of this agent on the uterus. It is apparent that the application of this insecticide to animals used for hormonal experiments introduces an additional variable.
Radioactive Dating of Tertiary Plant-Bearing Deposits
Authors: Rouse Glenn E. , Mathews W. H.
Published: October 2006

Four potassium-argon determinations from Tertiary rocks in the interior of British Columbia have yielded dates ranging from 45 to 49 million years. This suggests contemporaneity of three separate localities within the Middle Eocene epoch. Abundant plant micro- and macrofossils support this conclusion and indicate a flora quite different from floras of comparable age in western United States.
Possible Effect of Lethal Visible Light on Year-Class Fluctuations of Aquatic Animals
Authors: Perlmutter Alfred
Published: October 2006

Visible light killed the eggs and developing embryos of brook and rainbow trout. It is hypothesized that light could kill the eggs and embryos of all aquatic vertebrates and invertebrates. Adaptations minimize but do not completely block this lethal effect. Under some circumstances, visible light could cause heavy mortality in a new year-class of an aquatic animal.
Sarsen Stones of Stonehenge
Authors: Hill Patrick Arthur
Published: October 2006

A route via Lockeridge and the Avon Valley, involving a slide down the chalk escarpment, is postulated for the sarsen stones of Stonehenge. The transportation problem would have been greatly simplified if the stones had been relayed from point to point over snow or slush during successive winters. Markings on the stones hitherto undescribed are interpreted.
Maintenance of Normal in situ Chromosomal Features in Long-Term Tissue Cultures
Authors: Yerganian George , Leonard Ary J.
Published: October 2006

Clonal isolates from a rapidly proliferating fibroblast-like derivative have retained the classic diploid chromosome relationship over a period of many transplant generations. The readily identified members of the 11 pairs of chromosomes, including the sex chromosomes (X
1
and X
2
), have aided in localizing minute structural alterations within recloned diploid and aneuploid sublines.
Excitation and Inhibition of Neuronal Firing in Visual Cortex by Reticular Stimulation
Authors: Fuster Joaquin M.
Published: October 2006

The frequency of action potentials of about one-third of the neurons sampled in the striate cortex of awake rabbits was clearly modified by mild stimulation of the reticular core of the brain stem. Reticular stimulation often brought about enhancement of firing in units activated by light, while it usually had the contrary effect upon light-inhibited units.
Exploration of Venus by Radar
Authors: Victor W. K. , Stevens R.
Published: October 2006

A new tool is available to scientists for exploring the solar system, and modern-day explorers are discovering new worlds by radar. On 10 May 1961 a radar signal was beamed at the planet Venus, and for the first time in history the return echo was detected within a few minutes. A new value for the Astronomical Unit has been determined. The data indicate that Venus rotates slowly and that it is a better radio reflector than the moon.
Fatigue in Phasic and Tonic Fibers of Frog Muscle
Authors: Eberstein Arthur , Sandow Alexander
Published: October 2006

Single isolated phasic muscle fibers and small bundles of tonic fibers were directly stimulated in one-per-second twitch series by massive electrode shocks. During the stimulation period the isometric tension developed by the phasic fiber continuously decreased, first rapidly and then slowly. The tonic fibers behaved similarly, but showed much less fatigue than the phasic ones. In general, recovery of the fibers after cessation of stimulation also occurred in two phases.
Antiviral Effect of Guanidine
Authors: Rightsel Wilton A. , Dice John R. , McAlpine R. J. , Timm Eugene A. , McLean I. W. , Dixon Glen J. , Schabel Frank M.
Published: October 2006

It has been found that soluble guanidine salts show an antiviral effect on poliovirus and on some other enteroviruses. The activity was first detected in a cell culture screening system when the guanidine salt of hydroxyaminomethylene malononitrile inhibited the cytopathic effect of poliovirus in cell cultures. The studies were extended to various in vivo experiments in which the suggestive therapeutic activity of guanidine salts was again observed in monkeys infected with poliovirus. While these drugs cannot be considered for use in human disease because of severe toxicity, it is significant that potential antiviral compounds detected by the cell culture test show in vivo activity and point to the validity of such direct chemotherapeutic trials.
Behavior Studies by Capacitance Sensing
Authors: Kavanau J. Lee , Norris Kenneth S.
Published: October 2006

The movements of small burrowing animals submerged in sand are monitored through capacitance changes which detune radio-frequency oscillators. A new dimension of reptilian activity studies is possible by using this technique. Some early observations of several reptile species maintained in darkness in isothermal sand are given. Patterns of behavior during active phases, depth and rate of diving, and duration of quiescent periods are being revealed in detail for the first time.
Immunization to
Schistosoma mansoni
in Mice Inoculated with Radiated Cercariae
Authors: Villella John B. , Gomberg Henry J. , Gould S. E.
Published: October 2006

Preliminary experiments indicate that mice inoculated with cercariae of
Schistosoma mansoni
that have been exposed to cobalt-60 radiation in the range of 2500 to 3000 rep develop immunity to reinfection with nonradiated cercariae.
Licking Rates in Infant Albino Rats
Authors: Schaeffer Robert W. , Premack David
Published: October 2006

Two groups of neonatal rats raised from birth without the opportunity to drink, and tested at different age levels, exhibited the same general characteristics of licking rate that adult rats do. This suggests that licking in the rat is organized on a genetic-maturational basis.
Relative Reinforcement Values of Food and Intracranial Stimulation
Authors: Kling J. W. , Matsumiya Yoichi
Published: October 2006

Rats trained in a discrimination-reversal situation with either food pellets or intracranial stimulation as the reinforcing stimulus were not appreciably different in their first-task performance, but reversal training was slower if the first discrimination was learned with brain stimulation.
Cell Wall Replication in
Streptococcus pyogenes
Authors: Cole Roger M. , Hahn Jerome J.
Published: October 2006

Group A streptococci (
Streptococcus pyogenes
) of several different serological types were grown in fluorescein-labeled homologous type or group-specific globulins, thereby labeling the antigen-containing cell walls. Specific precipitation or inhibition of the labeled antibody, followed by continued incubation and examination at intervals by ultraviolet, phase, and dark-field microscopy, showed that new cell wall was then nonfluorescent. These nonfluorescent portions were differentiated by a reverse technique of culture in unlabeled globulin, followed by antibody precipitation, further growth, and fluorescent-antibody staining. This technique of differential labeling of cell wall has permitted following, for the first time in a living system, the fate of cell wall formed at different times. The results suggest that cell wall synthesis in actively growing cultures usually occurs simultaneously at least two sites per coccus, each site representing stages in successive divisions, and that cell wall growth in
Streptococcus pyogenes
is not by diffuse intercalation with old wall, but is initiated at and extends both peripherally and centripetally from the coccal equator.
Oxidation of Carbon-14 Labeled Galactose by Subjects with Congenital Galactosemia
Authors: Segal Stanton , Blair Alberta , Topper Yale J.
Published: October 2006

Galactose-1-C
14
oxidation was studied in eight individuals with congenital galactosemia. Although two of these subjects fulfilled the usual diagnostic criteria for this disorder, they oxidized the intravenously administered sugar to C
14
O
2
in a nearly normal fashion.
Rainfall and Deposition of Strontium-90 in Clallam County, Washington
Authors: Hardy Edward , Alexander Lyle T.
Published: October 2006

A linear relationship between cumulative strontium-90 deposition and rainfall has been observed from measurements made at five sites on the Olympic Peninsula. When an estimated contribution from dry deposition is subtracted from the measured total, the strontium-90 concentration in precipitation is seen to be independent of the amount of precipitation.
Effects of Increments and Decrements of Light on Neural Discharge Rate
Authors: De Valois Russell L. , Jacobs Gerald H. , Jones Arthur E.
Published: October 2006

Neurons in the lateral geniculate nucleus of the monkey discharge impulses periodically under conditions of both dark and light adaptation. Brief intensity changes in one direction produce decreases in firing rate roughly proportional to the logarithm of the intensity; intensity changes in the other direction produce corresponding increases in firing in the same neuron.
Flight Behavior of a Fly Alighting on a Ceiling
Authors: Hyzer William G.
Published: October 2006

Salient features in the maneuvers executed by a house fly (
Musca domestica
) in ascending to land on the underside of a horizontal surface have been observed in photographs exposed in a continuous-writing high-speed framing camera. Details of the action and the instrumentation required to record it are described.
Utilization of Nitrogen Compounds by Unicellular Algae
Authors: Birdsey Elizabeth C. , Lynch Victoria H.
Published: October 2006

Eight Chlorophyta employ urea as a sole nitrogen source; five utilize uric acid and xanthine. The Cyanophyta, Rhodophyta, and Euglenophyta studied do not grow on these three nitrogen sources, although
Anacystis nidulans
decomposes uric acid to allantoin. None of the algae tested utilized either allantoin or creatinine.
Diffusion of Carbon Monoxide through Thin Layers of Hemoglobin Solution
Authors: Mochizuki M. , Forster R. E.
Published: October 2006

The facilitation of carbon monoxide flux through a thin layer of hemoglobin solution is increased in the presence of oxygen. This is consistent with the hypothesis that the facilitation results from diffusion of carbon monoxide—hemoglobin as well as carbon monoxide, but that the overall process is partially limited by the reaction rates of carbon monoxide and hemoglobin.
Scotopic Spectral Sensitivity in the Monkey
Authors: Blough Donald S. , Schrier Allan M.
Published: October 2006

Three rhesus monkeys learned to adjust a small illuminated spot to threshold intensity. Then, while dark adapted, they "tracked" their thresholds to stimuli spaced across the visible wavelength spectrum. Spectral sensitivity functions were determined for each animal from these threshold records. The functions agreed well with results obtained from a human subject in the same apparatus, and with the standard human scotopic function defined by the International Commission on Illumination. However, the monkeys' relative sensitivity was slightly higher in the long-wavelength portion of the spectrum.
"Ages" of the Sikhote Alin Iron Meteorite
Authors: Fisher David E.
Published: October 2006

Measurements of the potassium and argon content of the Sikhote Alin iron meteorite, by activation analysis, enable a potassium-argon "age" of 1.7 × 10
9
years to be calculated. Such an age is vastly different from all the ages previously measured for iron meteorites.
Norepinephrine Synthesis from Tyrosine-C
14
in Isolated Perfused Guinea Pig Heart
Authors: Spector Sidney , Sjoerdsma Albert , Zaltzman-Nirenberg Perola , Levitt Morton , Udenfriend Sidney
Published: October 2006

The isolated, perfused guinea pig heart contains all the catalysts required to form norepinephrine from the dietary precursor, tyrosine. The conversion of tyrosine-C
14
to norepinephrine in the perfused heart occurred at a rate comparable to that estimated for this conversion in vivo. To account for the maintenance of norepinephrine stores in the normal heart, it is not necessary to postulate that the hormone is extracted from the blood.
Breakdown of Rat-Liver Ergosomes in vivo after Actinomycin Inhibition of Messenger RNA Synthesis
Authors: Staehelin Theophil , Wettstein Felix O. , Noll Hans
Published: October 2006

Ribosomes isolated from rat liver occur predominantly in the form of aggregates (ergosomes) corresponding to multiples of 73
S
particles held together by messenger RNA. After injecting rats with actinomycin, these aggregates gradually break down in vivo to 73
S
monomers and 113
S
dimers. We conclude that the observed breakdown results from the degradation of messenger RNA and the prevention by actinomycin of the synthesis of new messenger RNA.
Neutron Activation Analysis of Fluid Inclusions for Copper, Manganese, and Zinc
Authors: Czamanske Gerald K. , Roedder Edwin , Burns Forrest C.
Published: October 2006

Microgram quantities of copper, manganese, and zinc, corresponding to concentrations greater than 100 parts per million, were found in milligram quantities of primary inclusion fluid extracted from samples of quartz and fluorite from two types of ore deposits. The results indicate that neutron activation is a useful analytical method for studying the content of heavy metal in fluid inclusions.
Maskelynite: Formation by Explosive Shock
Authors: Milton Daniel J. , De Carli Paul S.
Published: October 2006

When high pressure (250 to 300 kilobars) was applied suddenly (shock-loading) to gabbro, the plagioclase was transformed to a noncrystalline phase (maskelynite) by a solid-state reaction at a low temperature, while the proxene remained crystalline. The shock-loaded gabbro resembles meteorites of the shergottite class; this suggests that the latter formed as a result of shock. The shock-loading of gabbro at 600 to 800 kilobars raised the temperature above the melting range of the plagioclase.
Growth-Regulating Chemicals Persist in Plants: Qualitative Bioassay
Authors: Muzik T. J. , Whitworth J. W.
Published: October 2006

Scions from untreated tomato plants were grafted on plants treated with 2,4-dichlorophenoxyacetic acid by dipping one leaf in a solution containing 1000 parts per million. Subsequent malformations of the scion shoot and leaves were used as criteria of the presence of this chemical. The chemical or a substance causing similar symptoms persisted in the plant in physiologically active amounts for approximately 60 days.
Behavioral Response Rates in Pigeons: Effect of α-Methyl-
m
-tyrosine
Authors: Hingtgen J. N. , Aprison M. H.
Published: October 2006

An intramuscular injection of α-methyl-m-tyrosine (100 mg/ kg), which differentially depletes serotonin and norepinephrine in both brain and heart, was given to two groups of pigeons trained to peck at a key for food. The first group received an injection 12 hours before the daily session and showed no behavioral effect. Response rates of birds in the second group, which were injected 30 minutes after the start of the daily session, decreased and returned to normal within 9 hours after injection. Preliminary data on brain serotonin of pigeons indicate that the disruption of the behavior follows the same time course as the change in serotonin.
Congenital Malformations in Hamster Embryos after Treatment with Vinblastine and Vincristine
Authors: Ferm Vergil H.
Published: October 2006

Intravenous injection of vinblastine or vincristine, two antitumor chemotherapeutic agents used in humans, into pregnant golden hamsters on the 8th day of gestation, causes an increase in the fetal mortality rate and the appearance of a significant number of congenital malformations in the surviving fetuses.
Signal Analysis of Evoked Potentials Recorded from Cats during Conditioning
Authors: John E. Roy , Ruchkin Daniel S. , Villegas Jorge
Published: October 2006

Correlation coefficients were computed between average response waveforms recorded from different brain regions of trained cats, before and after a specific stimulus acquired cue value. Application of signal-analysis techniques to the correlation matrix shows marked increase in the similarity between waveshapes evoked by that stimulus in sensory-specific and nonsensory-specific regions.
Varved Marine Sediments in a Stagnant Fjord
Authors: Gross M. Grant , Gucluer Sevket M. , Creager Joe S. , Dawson William A.
Published: October 2006

Varved sediments, containing planktonic marine diatoms, occur in Saanich Inlet, British Columbia. An olive-gray lamina, rich in opal, apparently forms during the bloom of
Skeletonema costatum
in the spring or summer, after which an olive-black lamina is deposited.
Tanning in the Adult Fly: A New Function of Neurosecretion in the Brain
Authors: Fraenkel G. , Hsiao Catherine
Published: October 2006

Tanning in the newly emerged fly is induced by a hormone secreted by neurosecretory cells situated in the pars intercerebralis of the brain. The same hormone is contained in the compound ganglion of the thorax, in concentrations six times as high as in the brain. This hormone is believed to act directly on the effector organ, and not through the secretion of ecdyson or a corpus allatum hormone; its release is effected through nervous impulses reaching the brain by way of the ventral nervous system a few minutes after the fly has emerged from the puparium. The hormone appears to be different from both the prothoracotropic and the gonadotropic hormones.
Miocene Fossil Hominids and the Chimp-Human Clade
Authors: Begun David R.
Published: October 2006

Miocene hominoids from Europe are among the earliest members of the great ape and human clade (the Hominidae). One of these forms, represented by well-preserved cranial remains from Rudabánya, Hungary, sheds new light on the question of the evolutionary relations among living hominids. This new evidence supports the view that humans have a specific evolutionary relation with chimpanzees, to the exclusion of all other apes.
Atomic Structure of the DNA Repair [4Fe-4S] Enzyme Endonuclease III
Authors: Kuo Che-Fu , McRee Duncan E. , Fisher Cindy L. , O'Handley Suzanne F. , Cunningham Richard P. , Tainer John A.
Published: October 2006

The crystal structure of the DNA repair enzyme endonuclease III, which recognizes and cleaves DNA at damaged bases, has been solved to 2.0 angstrom resolution with an R factor of 0.185. This iron-sulfur [4Fe-4S] enzyme is elongated and bilobal with a deep cleft separating two similarly sized domains: a novel, sequence-continuous, six-helix domain (residues 22 to 132) and a Greek-key, four-helix domain formed by the amino-terminal and three carboxyl-terminal helices (residues 1 to 21 and 133 to 211) together with the [4Fe-4S] cluster. The cluster is bound entirely within the carboxyl-terminal loop with a ligation pattern (Cys-X
6
-Cys-X
2
-Cys-X
5
-Cys) distinct from all other known [4Fe-4S] proteins. Sequence conservation and the positive electrostatic potential of conserved regions identify a surface suitable for binding duplex B-DNA across the long axis of the enzyme, matching a 46 angstrom length of protected DNA. The primary role of the [4Fe-4S] cluster appears to involve positioning conserved basic residues for interaction with the DNA phosphate backbone. The crystallographically identified inhibitor binding region, which recognizes the damaged base thymine glycol, is a seven-residue β-hairpin (residues 113 to 119). Location and side chain orientation at the base of the inhibitor binding site implicate Glu
112
in the
N
-glycosylase mechanism and Lys
120
in the β-elimination mechanism. Overall, the structure reveals an unusual fold and a new biological function for [4Fe-4S] clusters and provides a structural basis for studying recognition of damaged DNA and the
N
-glycosylase and apurinic/apyrimidinic-lyase mechanisms.
Crystallization of SE Polyoma Virus
Authors: Murakami William T.
Published: October 2006

Crystals have been obtained from purified preparations of SE polyoma virus. Specific infectivity measurements of the mother liquor, wash fractions, and the dissolved crystals indicate the viral nature of the crystals.
Lactic Dehydrogenase: Genetic Control in Man
Authors: Nance Walter E. , Claflin Alice , Smithies Oliver
Published: October 2006

A genetically determined variant of lactic dehydrogenase has been observed in the red cells of four members of two generations of a Brazilian family. The appearance of the variant after starch-gel electrophoresis of the hemolysates supports the concept that the lactic dehydrogenase isozymes are determined by the interaction of two subunits which are under separate genetic control. The products of the mutant and normal allele do not, however, appear to associate randomly to form isozymes. The similarity of the relative retardation of normal and mutant isozymes in gels made with increasing concentrations of starch suggests that they do not differ significantly in size.
Poisoning by DDT: Relation between Clinical Signs and Concentration in Rat Brain
Authors: Dale William E. , Gaines Thomas B. , Hayes Wayland J. , Pearce George W.
Published: October 2006

The severity of signs of poisoning in rats after a single dose of DDT is directly proportional to the concentration of the compound in their brains. The concentrations associated with death after one large dose are about the same as those after many smaller doses.
Lens Development: Fiber Elongation and Lens Orientation
Authors: Coulombre Jane L. , Coulombre Alfred J.
Published: October 2006

When the lens of the 5-day chick embryo is surgically reversed so that its epithelium faces the neural retina the elongation of those lens cells which have already differentiated is arrested and the epithelial cells differentiate into a new set of lens fibers. This internal reorganization, together with a reversal in polarity at the lens equator, results in a complete reversal of the polarity of the entire lens.
Variation in the Monoterpenes of
Pinus ponderosa
Laws
Authors: Smith Richard H.
Published: October 2006

Wide differences from tree to tree were found in the monoterpene composition of the wood oleoresin of ponderosa pines located in the same geographic area in California. Differences attributable to variation within the tree, to the season of sampling, to the year of sampling, and to methods of analysis by gas chromatography were only slight. There may be an inverse relation between the amounts of Δ
3
-
carene and β-pinene in a given tree.
Mimicry: Differential Advantage of Color Patterns in the Natural Environment
Authors: Brower Lincoln Pierson , Brower Jane Van Zandt , Stiles F. G. , Croze H. J. , Hower A. S.
Published: October 2006

With a new modification of the release and recapture technique in which day-flying male moths are artificially painted, released, and then lured by their females into traps, it has been possible to obtain differential recapture frequencies in natural areas of the Neotropics.
Twilight Phenomena Caused by the Eruption of Agung Volcano
Authors: Volz F. E.
Published: October 2006

Increase in twilight glow and in the dust stripes in the twilight arch have been observed from several places in the northern hemisphere from the fall of 1963 until now. Measurements of the twilight brightness indicate a considerable increase of dustiness in the stratosphere; this turbidity may be due to drifting ashes from the eruption of Agung volcano on Bali.
DNA Contents of Chromosome Ph
1
and Chromosome 21 in Human Chronic Granulocytic Leukemia
Authors: Rudkin George T. , Hungerford David A. , Nowell Peter C.
Published: October 2006

The Philadelphia
1
chromosome, characteristic of chronic granulocytic leukemia, contained 61± 1 percent as much DNA as a number 21 (or 22) chromosome from which it is believed to be derived. The remaining 39 percent represents 0.5 percent of a diploid chromosome complement, approximately 2 × 10
7
nucleotide pairs; the method used was not sensitive enough to detect whether it had been translocated to other chromosomes.
Nucleotides: Separation from an Alkaline Hydrolysate of RNA by Thin-Layer Electrophoresis
Authors: DeFilippes Frank M.
Published: October 2006

Mixtures of the 2′, 3′ nucleoside monophosphates obtained from an alkaline hydrolysis of RNA can be resolved into the four main RNA mononucleotides by electrophoresis on thin layers of cellulose. The separated nucleotides are recovered by removing the cellulose layer from the supporting glass plate and suspending the cellulose layer in
tris
hydrochloride buffer. The extracted cellulose is removed by low-speed centrifugation.
Archeology as Anthropology: A Case Study
Authors: Longacre William A.
Published: October 2006

Anthropological inferences, made possible by advances in techniques for collecting data in archeological field work and the processing of data with a computer, permit a comparison to be made between the modern western Pueblos and their prehistoric background. One point in the development of Pueblo social organization (approximately A.D. 1200) is examined and compared with the present.
Prehistoric Fauna From Shanidar, Iraq
Authors: Perkins Dexter
Published: October 2006

A comparative analysis of the faunal material from Shanidar Cave and the nearby proto-Neolithic site of Zawi Chemi Shanidar indicates that sheep were domesticated at Zawi Chemi Shanidar at the beginning of the 9th millennium B.C., more than 1000 years earlier than the earliest known evidence of animal husbandry.
Cloning of a Subunit of Yeast RNA Oolymerase II Transcription Factor b and CTD Kinase
Authors: Gileadi Opher , Feaver William J. , Kornberg Roger D.
Published: October 2006

Yeast RNA polymerase II initiation factor b copurifies with three polypeptides of 85, 73, and 50 kilodaltons and with a protein kinase that phosphorylates the carboxyl-terminal repeat domain (CTD) of the largest polymerase subunit. The gene that encodes the 73-kilodalton polypeptide, designated
TFB1
, was cloned and found to be essential for cell growth. The deduced protein sequence exhibits no similarity to those of protein kinases. However, the sequence is similar to that of the 62-kilodalton subunit of the HeLa transcription factor BTF2, suggesting that this factor is the human counterpart of yeast factor b. Immunoprecipitation experiments using antibodies to the
TFB1
gene product demonstrate that the transcriptional and CTD kinase activities of factor b are closely associated with an oligomer of the three polypeptides. Photoaffinity labeling with 3′-
O
-(4-benzoyl)benzoyl-ATP (adenosine triphosphate) identified an ATP-binding site in the 85-kilodalton polypeptide, suggesting that the 85-kilodalton subunit contains the catalytic domain of the kinase.
Gamma Globulin Antigenic Types Defined by Heavy Chain Determinants
Authors: Ballieux Rudy E. , Bernier George M. , Tominaga Kikuo , Putnam Frank W.
Published: October 2006

Two populations of immunologically distinguishable 7
S
gamma globulins in normal human serum and two corresponding antigenic types of myeloma 7
S
gamma globulins have been detected with rabbit antiserums to proteins associated with pathological conditions, the differences being related to the H-chains of 7
S
gamma globulin. No relationship exists with type I and type II antigenic classification, determined by L-chains. Human serums with various hereditary gamma globulin (Gm) specificities contain both types of 7
S
gamma globulin.
Gastric Erosions in the Rat: Effects of Immobilization at Different Points in the Activity Cycle
Authors: Ader Robert
Published: October 2006

Predictable, cyclic patterns of activity were obtained from 30 male rats. Seventeen of these were subjected to physical immobilization just as they were approaching their period of peak activity and thirteen animals were restrained during the inactive phase of their cycle. Eight animals were found to have gastric erosions following the immobilization. All of these came from the group immobilized during the time they would have been in the active phase of their particular cycle.
Potassium-Argon and Lead-Alpha Ages of Plutonic Rocks, Bokan Mountain Area, Alaska
Authors: Lanphere Marvin A. , MacKevett E. M. , Stern T. W.
Published: October 2006

Most of the granitic rocks in the Bokan Mountain area, southeastern Alaska, are early Paleozoic (probably Ordovician) judged by potassium-argon and lead-alpha age measurements. The Bokan Mountain Granite, the youngest intrusive unit in the area, belongs to a Mesozoic plutonic episode. These age measurements are the first direct evidence for the emplacement of early Paleozoic granitic intrusive rocks close to the Pacific margin of North America.
Tumor-Promoting Activity of Extracts of Unburned Tobacco
Authors: Bock Fred G. , Moore George E. , Crouch Shirley K.
Published: October 2006

Both an aqueous Bα(OH)
2
extract and an acetone-benzene extract of unburned cigarette tobacco produced skin tumors when painted on mice previously treated with 125 μg of 7,12-dimethylbenz[
a
]anthracene. The extract from as little as 0.5 cigarette per day was effective. The data are of interest in connection with epidemiological evidence that tobacco chewing is a cause of oral cancer. The data also suggest that tumor-promoting agents in cigarette smoke may have their source in the unburned tobacco.
Strychnine: Its Facilitating Effect on the Solution of a Simple Oddity Problem by the Rat
Authors: Hudspeth William J.
Published: October 2006

The learning of a brightness discrimination, discrimination reversal, and a simple oddity problem by rats was facilitated when the rats were given injections of strychnine sulfate after daily training sessions. Control rats injected with saline made significantly more errors during training on the first two tasks and failed to solve the oddity problem.
Encoding of a Homolog of the IFN-γ Receptor by Myxoma Virus
Authors: Upton Chris , Mossman Karen , McFadden Grant
Published: October 2006

Many poxvirus-encoded virulence factors have been identified as proteins that are secreted from infected cells. The major secreted protein (37 kilodaltons) from cells infected with myxoma virus is encoded by the M-T7 open reading frame. This protein has significant sequence similarity to the human and mouse receptors for interferon-gamma (IFN-γ). Furthermore, the myxoma M-T7 protein specifically binds rabbit IFN-γ and inhibits the biological activity of extracellular IFN-γ, one of the key regulatory cytokines in the host immune response against viral infections.
Light: Evidence for Its Direct Effect on Hypothalamic Neurons
Authors: Lisk R. D. , Kannwischer L. R.
Published: October 2006

Continuous light impinging on the suprachiasmatic region of enucleate rats resulted in a constant estrous-like vaginal cycle. The lowest percentage of cornified cells was obtained from exposure of the arcuate or mammillary neurons to light. Ovarian and pituitary weight increased significantly after exposure of the arcuate region to continuous light.