bluuebunny/crossref_metadata_2025 huggingface dataset:
Bone Marrow Histogenesis: A Comparison of Fatty and Red Marrow
Authors: Tavassoli Mehdi , Crosby William H.
Published: October 2006

Histogenesis of fatty marrow in extramedullary sites was compared to histogenesis of the red marrow. Both tissues undergo a similar sequence of events leading to reconstruction of hemopoietic marrow nodules. Histogenesis of yellow marrow then continues; such implants become nodules of fatty marrow, whereas implants of red marrow remain hemopoietically active. This observation supports the concept that histogenesis of the bone marrow recapitulates the ontogeny of this organ and indicates an intrinsic difference between the stroma of red and yellow marrow.
Contraceptives and Dysplasia: Higher Rate for Pill Choosers
Authors: Stern Elizabeth , Clark Virginia A. , Coffelt Carl F.
Published: October 2006

Among women choosing the pill in preference to other contraceptive methods there is a higher rate of the cancer precursor, dysplasia of the cervix, before any possible effect of the pill.
Phosphorus, Nitrogen, and Algae in Lake Washington after Diversion of Sewage
Authors: Edmondson W. T.
Published: October 2006

After diversion of sewage effluent from Lake Washington, winter concentrations of phosphate and nitrate decreased at different rates. From 1963 to 1969, phosphate decreased to 28 percent of the 1963 concentration, but nitrate remained at more than 80 percent of the 1963 value. Free carbon dioxide and alkalinity remained relatively high. The amount of phytoplanktonic chlorophyll in the summer was very closely related to the mean winter concentration of phosphate, but not to that of nitrate or carbon dioxide.
Bone Marrow Colonies: Stimulation in vitro by Supernatant from Incubated Human Blood Cells
Authors: Chervenick Paul A. , Boggs Dane R.
Published: October 2006

A substance which stimulates growth of granulocytic and mononuclear cell colonies from mouse and human bone marrow was produced by incubated human blood cells. It is resistant to heat and freezing and is not dialyzable. Intact irradiated and unirradiated cells had very little activity, and sonically disrupted cells had no activity. The addition of plasma or sonically disrupted cells to the cell supernatant decreased its activity.
Prostaglandin Receptor Site: Evidence for an Essential Role in the Action of Luteinizing Hormone
Authors: Kuehl F. A. , Humes J. L. , Tarnoff J. , Cirillo V. J. , Ham E. A.
Published: October 2006

A dose-response relation was established between prostaglandins and formation of adenosine 3′,5′-monophosphate in the mouse ovary. The prostaglandin antagonist, 7-oxa-13-prostynoic acid, blocked the stimulatory effect of prostaglandin E
1
, prostaglandin E
2
, and luteinizing hormone on adenosine 3′,5′-monophosphate formation in a competitive manner. Kinetic studies made it possible to suggest that there is a single luteinizing-hormone-related prostaglandin receptor in mouse ovaries, and that activation of this prostaglandin receptor is an essential requirement in the action of luteinizing hormone to stimulate adenosine 3′,5′-monophosphate formation and steroidogenesis.
Myeloperoxidase: Contribution to the Microbicidal Activity of Intact Leukocytes
Authors: Klebanoff Seymour J.
Published: October 2006

Azide and, to a lesser extent, cyanide inhibit the microbicidal activity of myeloperoxidase and of intact normal leukocytes, but they have little or no effect on peroxidase-negative leukocytes. The contribution of the azide-sensitive (peroxidase-dependent?) systems to the total microbicidal activity of normal leukocytes is considerable. The azide-insensitive antimicrobial systems are more highly developed in peroxidase-negative leukocytes than in normal leukocytes, thus suggesting an adaption.
Antitumor Activity in Mice of Tentacles of Two Tropical Sea Annelids
Authors: Tabrah Frank L. , Kashiwagi Midori , Norton Ted R.
Published: October 2006

Crude extracts of tentacles of two polychaetous annelids completely inhibit growth of Erlich ascites tumor in 60 to 100 percent of treated mice. Dialyzed extracts of one of these annelids,
Lanice conchilega
, show activity in the retentate after pronase digestion, suggesting that antitumor activity is associated with a nonprotein component of the crude tentacle extract.
Echo-Ranging Neurons in the Inferior Colliculus of Bats
Authors: Suga Nobuo
Published: October 2006

Bats measure the distance to an object in terms of the time lag between their outgoing orientation sounds and the returning echo. For measurement of the time lag, the latency of response of a neuron to a stimulus must be nearly constant regardless of the stimulus amplitude and envelope. Otherwise, a large error would be introduced into the measurement. Bats have neurons that are specialized for echo ranging.
Soluble HL-A7 Antigen: Localization in the β-Lipoprotein Fraction of Human Serum
Authors: Charlton Ronald K. , Zmijewski Chester M.
Published: October 2006

The HL-A7 antigen of human leukocytes occurs as a soluble, low-density lipoprotein in the serum of HL-A7-positive individuals. Its presence in high concentration may inhibit direct leukocyte grouping, leading to erroneous results. This finding affords an easy method for the preparation of monospecific cytotoxic antiserums by absorption with serum fractions rather than leukocytes.
Inflammation and Herpes Simplex Virus: Release of a Chemotaxis-Generating Factor from Infected Cells
Authors: Brier Arnold M. , Snyderman Ralph , Mergenhagen Stephan E. , Notkins Abner L.
Published: October 2006

Infection of primary rabbit kidney cells with herpes simplex virus leads to the release of a cell factor or factors that upon incubation with serum results in the cleavage of the fifth component, C5, of complement. The product of this cleavage, C5a, is chemotactic for polymorphonuclear leukocytes and could be responsible for the accumulation of these cells at the site of herpetic lesions.
Enhancement of the Glutamate Response by cAMP-Dependent Protein Kinase in Hippocampal Neurons
Authors: Greengard Paul , Jen Joanna , Nairn Angus C. , Stevens Charles F.
Published: October 2006

Receptor channels activated by glutamate, an excitatory neurotransmitter in the mammalian brain, are involved in processes such as long-term potentiation and excitotoxicity. Studies of glutamate receptor channels expressed in cultured hippocampal pyramidal neurons reveal that these channels are subject to neuromodulatory regulation through the adenylate cyclase cascade. The whole-cell current response to glutamate and kainate [a non-NMDA (
N
-methyl-D-aspartate) receptor agonist] was enhanced by forskolin, an activator of adenylate cyclase. Single-channel analysis revealed that an adenosine 3′,5′-monophosphate-dependent protein kinase (PKA) increases the opening frequency and the mean open time of the non-NMDA-type glutamate receptor channels. Analysis of synaptic events indicated that forskolin, acting through PKA, increased the amplitude and decay time of spontaneous excitatory postsynaptic currents.
Norepinephrine: Reversal of Anorexia in Rats with Lateral Hypothalamic Damage
Authors: Berger Barry D. , Wise C. David , Stein Larry
Published: October 2006

Injection of norepinephrine in the lateral ventricles of rats recovering from lateral hypothalamic anorexia caused immediate feeding and, frequently, overeating. Intraventricular administration of the α-noradrenergic blocker, phentolamine, suppressed feeding in both normal rats and rats that had recovered from lateral hypothalamic lesions. Feeding is reinforced by ascending medial forebrain bundle fibers that form α-noradrenergic synapses in the hypothalamus and forebrain. Damage to these fibers suppresses feeding by reducing noradrenergic transmission and, hence, the rewarding value of food. Recovery of feeding after hypothalamic lesions coincides with the recovery of noradrenergic reward function.
Acetoacetyl-Coenzyme A Thiolase in Brain, Liver, and Kidney during Maturation of the Rat
Authors: Dierks-Ventling Christa , Cone A. Lynn
Published: October 2006

The development of thiolase in various rat tissues from 7 days before birth to adulthood was studied. Enzyme activities in brain, liver, and kidney during the perinatal period reflect the nutritional environment, whereas those in the adult tissues do not.
Characterization of a Zinc Finger Gene Disrupted by the t(15;17) in Acute Promyelocytic Leukemia
Authors: Goddard Audrey D. , Borrow Julian , Freemont Paul S. , Solomon Ellen
Published: October 2006

The translocation t(15;17) associated with acute promyelocytic leukemia results in the fusion of the retinoic acid receptor alpha (
RARA
) gene to the
PML
gene. Characterization of
PML
revealed that it is a putative zinc finger protein and potential transcription factor that is commonly expressed, with at least three major transcription products.
PML
breakpoints cluster in two regions on either side of an alternatively spliced exon. Although leukemic cells with translocations characteristically express only one fusion product, both
PML
/
RARA
(on the 15q+ derivative chromosome) and
RARA
/
PML
(on the 17q- derivative) are transcribed.
Somatosensory Responses of Bulboreticular Units in Awake Cat: Relation to Escape-Producing Stimuli
Authors: Casey Kenneth L.
Published: October 2006

In awake, unrestrained cats, bulboreticular neurons respond after electrical stimulation of cutaneous nerve with increasing discharge as stimulus intensity is raised to levels eliciting escape behavior. These cells discharge most vigorously to noxious natural somatic stimuli and are not driven by other sensory modalities. Electrical stimulation through the recording microelectrode also elicits escape, which further suggests bulboreticular participation in pain sensory mechanisms.
Lunar Gravity Analysis from Long-Term Effects
Authors: Liu Anthony S. , Laing Philip A.
Published: October 2006

The global lunar gravity field was determined from a weighted least-squares analysis of the averaged classical element of the five Lunar Orbiters. The observed-minus-computed residuals have been reduced by a factor of 10 from a previously derived gravity field. The values of the second-degree zonal and sectorial harmonics are compatible with those derived from libration data.
Hemispheric Asymmetry of Electrocortical Responses to Speech Stimuli
Authors: Morrell Lenore K. , Salamy Joseph G.
Published: October 2006

In a group of normal adults, averaged cortical evoked responses to natural speech stimuli were recorded from scalp electrodes placed symmetrically over the two cerebral hemispheres at frontal, Rolandic, and temporoparietal leads. The amplitude of the most prominent component was consistently larger in left hemisphere derivations, with the major hemisphere difference observed in the temporoparietal records. These electrophysiological measures may be sensitive indicators of hemispheric specialization of function.
Anomalous Retinal Pathways in the Siamese Cat: An Inadequate Substrate for Normal Binocular Vision
Authors: Kalil Ronald E. , Jhaveri Sonal R. , Richards Whitman
Published: October 2006

All major retinal pathways in the Siamese cat are abnormal, with almost total crossing of the projections to the pretectum and superior colliculus. These projections represent a marked disruption in the customary neural substrate for binocular vision, which implies a consequent impairment in stereoscopic depth perception. Crossed eyes, commonly seen in the Siamese cat, may therefore arise from a neuroanatomical defect in the primary visual pathways.
Signaled Reinforcing Brain Stimulation Facilitates Operant Behavior under Schedules of Intermittent Reinforcement
Authors: Cantor Michael B.
Published: October 2006

When single, rewarding brain stimulations were made predictable by preceding them with a brief warning signal, operant behavior was established and maintained under fixed ratio 200, variable ratio 30, fixed interval 3-minute, variable interval 2-minute, and differential reinforcement of low rate 20-second schedules of intermittent reinforcement. When the warning signal was removed, overall response rate declined in all but the fixed ratio schedules and then returned to the previous rate when the signal was reinstated.
Submarine Pingos in the Beaufort Sea
Authors: Shearer J. M. , Macnab R. F. , Pelletier B. R. , Smith T. B.
Published: October 2006

Numerous underwater mounds found on the continental shelf of the Beaufort Sea are thought to be pingos (hills that have a central core of ice) which have formed in the marine environment subsequent to oceanic transgression.
Initiation of Protein Synthesis at an Unusual Position in an Immunoglobulin Gene?
Authors: Smithies O. , Poulik M. D.
Published: October 2006

The amino acid sequence of urinary β
2
-microglobulin has been partially determined and found to be related to the constant region of IgG immunoglobulin heavy chain. β
2
-Microglobulin is present in normal individuals. Its gene may have evolved from an immunoglobulin gene by the use of an unusually located start signal for initiating synthesis of the polypeptide.
Polychlorinated Biphenyls: Toxicity to Certain Phytoplankters
Authors: Mosser Jerry L. , Fisher Nicholas S. , Teng Tzu-Chiu , Wurster Charles F.
Published: October 2006

The growth rates of two species of marine diatoms were reduced by polychlorinated biphenyls (PCB's), widespread pollutants of the marine environment, at concentrations as low as 10 to 25 parts per billion. In contrast, a marine green alga and two species of freshwater algae were not inhibited at these or higher concentrations. The sensitivity of these species to PCB's paralleled their sensitivity to DDT [1,1,1-trichloro-2,2-bis(
p
-chlorophenyl)ethane].
Dihydroxyphenylalanine in Rat Food Containing Wheat and Oats
Authors: Hoeldtke R. , Baliga B. S. , Issenberg P. , Wurtman R. J.
Published: October 2006

Dopa has been identified in rat food by three different fluorimetric assays and paper chromatography. Incubation of the rat food with proteolytic enzymes dramatically increased the measurable free dopa. Analysis of samples of six individual protein-containing constituents of rat food revealed that both wheat and oats contain dopa.
Independence of Short- and Long-Term Memory: A Neural System Analysis
Authors: Kesner Raymond P. , Conner Hubert S.
Published: October 2006

Rats were given electrical stimulation to the midbrain reticular formation or to the hippocampus 4 seconds after they received shocks contingent on the animals' bar-press responses. They were retested for memory of the shocks 64 seconds or 24 hours after the shocks. The animals that received stimulation to the midbrain reticular formation showed amnesia at the 64-second retest and memory at the 24-hour retest. In contrast, animals that received stimulation to the hippocampus showed memory at the 64-second retest and amnesia at the 24-hour retest. The data support a dual, parallel-processing model of memory.
Primate Phylogeny and Immunological Distance
Authors: Lovejoy C. Owen , Burstein Albert H. , Heiple Kingsbury G.
Published: October 2006

Recalculation of the time of divergence of the Pongidae and Hominidae after correction of immunological distance by inclusion of generation length yields minimum dates of approximately 14 million years ago.
Feeding Produced in the Satiated Rat by Elevating the Concentration of Calcium in the Brain
Authors: Myers R. D. , Bender S. A. , Krstić M. K. , Brophy P. D.
Published: October 2006

When the concentration of calcium ions in the cerebral ventricles is elevated, a fully satiated rat eats voraciously. This feeding response is not prevented by prior intraventricular administration of alpha-or beta-adrenergic blocking agents, or other pharmacological antagonists. This supports the concept of an independent ionic mechanism, rather than a neurotransmitter one, for modulating a "set-point" for weight or hunger.
Viral RNA Subunits in Cells Transformed by RNA Tumor Viruses
Authors: Tsuchida Nobuo , Robin Martin S. , Green Maurice
Published: October 2006

Single-stranded 35
S
and 20
S
viral RNA species are synthesized in virus-producing mouse and rat cells transformed by the murine sarcoma virus. A transformed hamster cell line that does not produce virus synthesizes 35
S
, but not 20
S
viral RNA.
Blockade of Prolactin Action by an Antiserum to Its Receptors
Authors: Shiu Robert P. C. , Friesen Henry G.
Published: October 2006

A guinea pig antiserum to prolactin receptors selectively inhibited the binding of [
125
I]prolactin to its membrane receptors as well as prolactin-mediated incorporation of [
3
H]leucine into casein and transport of [
14
C]aminoisobutyric acid, but was without effect on the binding of [
125
I]insulin and insulin-mediated events in explants of rabbit mammary glands maintained in culture. These findings provide direct evidence for an obligatory functional role of a membrane receptor in mediating the action of a polypeptide hormone.
Goldfish Retina: Sign of the Rod Input in Opponent Color Ganglion Cells
Authors: Raynauld Jean-Pierre
Published: October 2006

After light adaptation, all "on-center" ganglion cells in the dark became "red on-center," and all "off-center" cells turned into "red off-center" cells. On a chance basis, this similitude of effect between the rods and the red cones in opponent color cells was not expected. These findings indicate that in the goldfish there is some similarity between the connections of the rods and of the long-wavelength cones.
Rostroconchia: A New Class of Bivalved Mollusks
Authors: Pojeta John , Runnegar Bruce , Morris Noel J. , Newell Norman D.
Published: October 2006

Four Paleozoic bivalved genera are assigned to the new molluscan class Rostroconchia:
Eopteria, Euchasma, Conocardium
, and
Pseudoconocardium
. These mollusks have an uncoiled univalved larval shell; an untorted bivalved adult shell; no hinge teeth, ligament, or adductor muscles; and a fused, almost inflexible. hinge. Rostroconchians developed separately from the pelecypods through the ribeirioids, but are regarded as more closely related to the Pelecypoda and Scaphopoda than to other known classes of mollusks.
Electron Diffraction of Wet Proteins: Catalase
Authors: Matricardi Victor R. , Moretz Roger C. , Parsons Donald F.
Published: October 2006

Electron diffraction patterns having 3500 reflections out to 2 angstroms were obtained from wet microcrystals of catalase. No diffraction was obtained if the water vapor pressure was set below 90 percent of the equilibrium value.
Facilitation of Recovery by α-Methyl-
p
-Tyrosine after Lateral Hypothalamic Damage
Authors: Glick Stanley D. , Greenstein Stuart , Zimmerberg Betty
Published: October 2006

Rats with bilateral lateral hypothalamic lesions die of starvation in approximately 7 days after surgery. Rats that were treated with α-methyl-
p
-tyrosine for 3 days prior to lateral hypothalamic surgery spontaneously eat, drink, and gain weight after surgery. These data suggest that recovery of function after lateral hypothalamic damage involves denervation supersensitivity.
Dibutyryl Cyclic Adenosine Monophosphate Stimulation of Colcemid-Inhibited Axonal Elongation
Authors: Roisen Fred J. , Murphy Richard A. , Braden Wanda G.
Published: October 2006

Adenosine 3′,5′-monophosphate (cyclic AMP) and its dibutyryl derivative induce a variety of morphological changes, including those associated with in vitro axonal maturation. Established sensory ganglia treated with dibutyryl cyclic AMP show significant increases in average axonal length and number in comparison with controls; those treated with maintenance doses of Colcemid show no increases in either parameter; simultaneous treatment with both agents results in growth statistically similar to that produced by dibutyryl cyclic AMP alone. The data are consistent with our hypothesis that cyclic AMP promotes axonal elongation by stimulating microtubule assembly from a preexisting subunit pool.
Control of Carcinogenesis: A Possible Role for the Activated Macrophage
Authors: Hibbs John B. , Lambert Lewis H. , Remington Jack S.
Published: October 2006

Cytotoxic activity of activated mouse macrophages against mouse embryo fibroblasts was tested before and after spontaneous transformation of the fibroblasts in vitro. Activated macrophages caused little or no destruction of untransformed fibroblasts but were markedly cytotoxic to the same fibroblasts after spontaneous transformation. The efferent limb of this cytotoxic reaction appears to be nonimmunologic and to be related to abnormal growth properties rather than to the antigenic composition of target cells.
Interferometric Observations of an Artificial Satellite
Authors: Preston R. A. , Ergas R. , Hinteregger H. F. , Knight C. A. , Robertson D. S. , Shapiro I. I. , Whitney A. R. , Rogers A. E. E. , Clark T. A.
Published: October 2006

Very-long-baseline interferometric observations of radio signals from the TACSAT synchronous satellite, even though extending over only 7 hours, have enabled an excellent orbit to be deduced. Precision in differenced delay and delay-rate measurements reached 0.15 nanosecond (≲ 5 centimeters in equivalent differenced distance) and 0.05 picosecond per second (≲ 0.002 centimeter per second in equivalent differenced velocity), respectively. The results from this initial three-station experiment demonstrate the feasibility of using the method for accurate satellite tracking and for geodesy. Comparisons are made with other techniques.
Arthropod Molting Hormone: Radioimmune Assay
Authors: Borst David W. , O'Connor John D.
Published: October 2006

A radioimmune assay for the arthropod molting hormone, ecdysterone, has been developed. The sensitivity of the assay is 200 picograms or 25 times the maximum sensitivity of the bioassay. Closely related steroids also bind the antibody, but with lower affinities.
Amphotericin B Methyl Ester Hydrochloride and Amphotericin B: Comparative Acute Toxicity
Authors: Keim G. R. , Poutsiaka J. W. , Kirpan J. , Keysser C. H.
Published: October 2006

In single-dose parenteral studies with mice and dogs, the methyl ester hydrochloride of amphotericin B proved to be significantly less toxic than the parent compound, especially to the kidney.
Nile Delta: The Defunct Pelusiac Branch Identified
Authors: Sneh A. , Weissbrod T.
Published: October 2006

The course of the ancient Pelusiac branch of the Nile River has been traced on a deltaic plain east of the Suez Canal, between the El Baqar Canal and Tell el Farama (ancient Pelusium). Two minor distributaries branched northward. The critical stage in the process of the silting up of the lower reaches of the Pelusiac branch, due to prograding beach accretion, occurred around A.D. 25. Ancient ruins in the area are closely associated with the courses.
Kilauea Volcano, Hawaii: A Search for the Volcanomagnetic Effect
Authors: Davis Paul M. , Jackson Dallas B. , Field James , Stacey Frank D.
Published: October 2006

Brief excursions of magnetic field differences between a base station and two satellite station magnetometers show only slight correlation with ground tilt at Kilauea Volcano. This result suggests that only transient, localized stresses occur during prolonged periods of deformation and that the volcano can support no large-scale pattern of shear stresses.
Intracellular Plutonium: Removal by Liposome-Encapsulated Chelating Agent
Authors: Rahman Yueh-Erh , Rosenthal Marcia W. , Cerny Elizabeth A.
Published: October 2006

Chelating agents, such as ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) were successfully encapsulated within lipid spherules (that is, liposomes). Encapsulated [
14
C]EDTA, given intravenously to mice, was retained longer in tissues than nonencapsulated [
14
C]EDTA. Encapsulated DTPA, given to mice 3 days after plutonium injection, removed an additional fraction of plutonium in the liver, presumably intracellular, not available to nonencapsulated DTPA. It also further increased urinary excretion of plutonium. Introduction of chelating agents into cells by liposomal encapsulation is a promising new approach to the treatment of metal poisoning.
A New Theory of Lunar Magnetism
Authors: Runcorn S. K. , Urey H. C.
Published: October 2006

In the hypothesis advanced here it is supposed that the field, in which rocks at the lunar surface acquired the remanent magnetization found through the Apollo project, arose from permanent magnetization of the deep interior of the moon. This theory involves the assumption that the moon, apart from a surface shell, accreted cold and remained below the Curie point of iron until sometime later than 3 × 10
9
years ago. The magnetization was acquired as the moon formed in a gas sphere in the strong magnetic field of the early sun.
Autoimmune Response to Acetylcholine Receptor
Authors: Patrick Jim , Lindstrom Jon
Published: October 2006

Injection of rabbits with acetylcholine receptor highly purified from the electric organ of
Electrophorus electricus
emulsified in complete Freund's adjuvant resulted in the production of precipitating antibody to acetylcholine receptor. After the second injection of antigen, the animals developed the flaccid paralysis and abnormal electromyographs characteristic of neuromuscular blockade. Treatment with the anticholinesterases edrophonium or neostigmine dramatically alleviated the paralysis and the fatigue seen in electromyography.
Genetic Polymorphism of Proline-Rich Human Salivary Proteins
Authors: Azen Edwin A. , Oppenheim Frank G.
Published: October 2006

In randomly collected saliva samples from 120 Caucasians, 79 Blacks, and 40 Chinese, three phenotypes were observed by electrophoresis in alkaline slab polyacrylamide gels. The proteins showing polymorphism were identical with four previously characterized proline-rich proteins. Inheritance is controlled by two autosomal codominant alleles. The gene frequencies were for Caucasians,
Pr
1
=0.73,
Pr
2
=0.27; for Blacks,
Pr
1
=0.80,
Pr
2
=0.20; for Chinese,
Pr
1
=0.84,
Pr
2
=0.16.
Reproductive Isolation of Two Tortricid Moth Species by Different Ratios of a Two-Component Sex Attractant
Authors: Minks A. K. , Roelofs W. L. , Ritter F. J. , Persoons C. J.
Published: October 2006

Two tortricid moth species,
Adoxophyes orana
and
Clepsis spectrana
, utilize the same two isomers,
cis
-9- and
cis
-11-tetradecenyl acetate, as their sex attractant. Communication between the sexes of each species is separated effectively by a different blending of both compounds by the females and a different response to these blends by the males.
Development of Rabbit Visual Cortex: Late Appearance of a Class of Receptive Fields
Authors: Grobstein Paul , Chow Kao Liang , Spear Peter D. , Mathers Lawrence H.
Published: October 2006

In young rabbits before the age at which the eyes open, only three of the seven receptive field types described in the adult visual cortex are detectable. The remaining four receptive field types—which share the property of having radially asymmetric fields—appear later, coincident with a decline in the percentage of cells that are visually responsive but not classifiable as to receptive field type.
Kitten Visual Cortex: Short-Term, Stimulus-Induced Changes in Connectivity
Authors: Pettigrew J. , Olson C. , Barlow H. B.
Published: October 2006

Single neurons in the kitten visual cortex can be induced to increase their responsiveness to a repeated stimulus applied while the neurons are under observation. These short-term changes are in the same direction as the permanent modifications produced in whole populations of neurons following environmental manipulations during the "critical period" of cortical development, but are less pronounced and probably transient.
Genetic Abnormality of the Visual Pathways in a "White" Tiger
Authors: Guillery R. W. , Kaas J. H.
Published: October 2006

"White" tigers show an inherited reduction of pigment, produced by an autosomal recessive gene. The brain of one of these tigers shows an abnormality of the visual pathways similar to abnormalities that are associated with albinism in many other mammals. There is a close relationship between the reduced pigment formation, the pathway abnormality, and strabismus.
Mechanical Resonance Spectra in Human Cancellous Bone
Authors: Pugh J. W. , Rose R. M. , Paul I. L. , Radin E. L.
Published: October 2006

The dynamic mechanical response of fresh human cancellous bone at low audio frequencies contains two resonance spectra. The spectral frequencies in each series have the ratios 1:4:9:16 ... n
2
. The frequencies are in quantitative agreement with the concept of momentum wave modes of calcium and phosphorus atoms in the lamellae, with no variable parameters.
Inherited Renal Cysts in Rats
Authors: Solomon Sidney
Published: October 2006

A strain of rats that form renal cysts has been developed. The number of visible cysts increases with age after animals are 20 days old. Micropuncture studies indicate that the cystic fluid has a variable sodium concentration, but that the ratios of inulin concentration in tubular fluid to that in plasma are high.
Seasonal Changes in the Learning and Activity Patterns of Goldfish
Authors: Shashoua Victor E.
Published: October 2006

Goldfish exhibit cyclic changes with an annual rhythm in their learning and activity patterns. Maximum learning ability and active behavior occurred during the months of January, February, and March. Poor learning was obtained in the summer months, after the onset of the spawning season. The results indicate that the annual periodic changes of the hormonal levels which govern spawning may also influence learning and activity patterns.
Male-Specific Antigen: Modification of Potency by the
H-2
Locus in Mice
Authors: Wachtel Stephen S. , Gasser David L. , Silvers Willys K.
Published: October 2006

Skin grafts from C57BL/10 (B10) male mice survive significantly longer than do B10.BR male skin grafts on (B10 × B10.BR)F
1
females. This indicates that the H-2 locus influences the potency of the male-specific antigen in mice.
Origin of the Mesoamerican 260-Day Calendar
Authors: Malmstrom Vincent H.
Published: October 2006

The sacred 260-day Mesoamerican calendar probably originated near a latitude of 15°N, where there is a 260-day interval between transits of the zenithal sun. Archeological and faunal evidence favors an origin in the Pacific lowlands rather than in the highlands near Copán, Honduras, although Copán, which is located at the 15th parallel of latitude, later became the principal Mayan astronomical center.
Cross-National Comparison of Population Density
Authors: Day Alice Taylor , Day Lincoln H.
Published: October 2006

The unresolved difficulties associated with defining and measuring population density strictly circumscribe the scope and nature of the conclusions that can be properly derived from differentials in man:land ratios. Any conclusions about human density will have meaning only to the extent that they are based on a recognition that this density must be viewed in both static and dynamic terms and that it cannot be isolated, in analysis, from either the social and cultural setting, the demographic characteristics of the population, or the broader processes of social change within the society. In and of itself, the familiar man:land ratio says more about area than it does about either the human experience of density or the relation of population to resources. This ratio is therefore essentially meaningless as an indicator of comparative conditions of life among different countries and different geographic regions. The mere fact of having a relatively low average population density, thus, does not automatically entitle a nation to complacency about its ability to adjust readily to future population change, either in terms of growth in numbers or in the geographic location of its people.
Thyroid Hormone Action: A Cell-Culture System Responsive to Physiological Concentrations of Thyroid Hormones
Authors: Samuels Herbert H. , Tsai Jir S. , Cintron Raquel
Published: October 2006

Cells from a rat pituitary tumor cell line will respond in vitro to physiological concentrations of L-thyroxine and L-triiodothyronine. The cells are grown in a culture medium that contains serum from a hypothyroid calf. Dose-response relationships of a variety of thyronine derivatives indicate that this system has a specificity of response which is similar to that observed in vitro.
Sustained Tolerance to a Specific Effect of Ethanol on Posttetanic Potentiation in
Aplysia
Authors: Traynor M. Elaine , Woodson Paul B. J. , Schlapfer Werner T. , Barondes Samuel H.
Published: October 2006

Perfusion with 0.8 molar ethanol in seawater specifically accelerates the rate of decay of posttetanic potentiation observed after repetitive electrical stimulation of an identified synapse in the abdominal ganglion of
Aplysia californica
. Repeated perfusion with seawater alternately with and without ethanol leads to a progressive diminution of this specific effect of ethanol, such that after the third application ethanol no longer has any effect on the rate constant of decay of posttetanic potentiation. This tolerance to the specific effects of ethanol persists for at least 11 hours after the last application of ethanol.
Asteroidal Source of Meteorites
Authors: Zimmerman Peter D. , Wetherill G. W.
Published: October 2006

The evolution of asteroidal orbits initially near the Kirkwood Gap at the 1:2 commensurability with Jupiter's period provides a mechanism for the production of meteorites from the asteroid belt without excessive velocity change. The resulting yield (∼ 10
9
grams per year) and the orbital elements of Earth-crossing objects are in agreement with observational data on meteorites.
Induction of an Enzyme in Genetically Deficient Rats after Grafting of Normal Liver
Authors: Mukherjee Anil B. , Krasner Joseph
Published: October 2006

Tissue from normal rat livers was grafted onto the livers of rats that were genetically deficient in bilirubin uridine diphosphate glucuronyltransferase activity. Twelve weeks after the grafting operation, the liver of the recipient rats had bilirubin uridine diphosphate glucuronyltransferase activity.
Periodicity of Susceptibility to Pneumococcal Infection: Influence of Light and Adrenocortical Secretions
Authors: Shackelford Penelope G. , Feigin Ralph D.
Published: October 2006

Circadian periodicity of susceptibility to pneumococcal infection was altered but not abolished in blind or adrenalectomized mice. Serum corticosterone concentrations 24 hours after pneumococcal challenge were greatest in animals challenged at 0400 hours, a time when circulatory corticosterone is lowest; the smallest absolute increase in serum corticosterone followed challenge at 1600 hours.
Acquisition and Retention of Long-Term Habituation in
Aplysia
: Correlation of Behavioral and Cellular Processes
Authors: Carew Thomas J. , Kandel Eric R.
Published: October 2006

To examine the cellular mechanisms responsible for transition from a short-term to a long-term behavioral modification, a rapid training procedure was developed for producing long-term habituation of the defensive withdrawal of gill and siphon in
Aplysia
. Four ten-trial training sessions, with 1½-hour intersession intervals, produced habituation that was retained for more than 1 week. This 5-hour procedure could be applied to a test system in the isolated abdominal ganglion where the cellular changes accompanying the acquisition of long-term habituation can be examined. During acquisition, intracellular recordings were obtained from L7, a major gill and siphon motor neuron, and the pattern of stimulation used in the behavioral experiments was applied to an afferent nerve. Acquisition was associated with a progressive decrease in the complex excitatory synaptic potential produced in L7 by afferent nerve stimulation. When retention was tested 24 hours later, the synaptic decrement was still evident. Thus, a behaviorally meaningful stimulus sequence, consisting of only 40 patterned stimuli, leads to changes in synaptic effectiveness lasting one or more days in a neural pathway involved in short-term habituation of this reflex.
Transvaal Stromatolite: First Evidence for the Diversification of Cells about 2.2 × 10
9
Years Ago
Authors: Nagy Lois Anne
Published: October 2006

The well-preserved fossil remnants of filamentous blue-green algae have been found in petrographic thin sections of a dolomitic limestone stromatolite in the Transvaal Sequence of South Africa. Some of these filaments contain enlarged cells which are interpreted as akinetes. A new species and genus,
Petraphera vivescenticula
, is proposed for this microfossil, which is morphologically similar to the living cyanophyte genus
Raphidiopsis
. This would constitute the first known occurrence of cell diversification in the Precambrian with an age of about 2.2 × 10
9
years.
Gating Currents of the Sodium Channels: Three Ways to Block Them
Authors: Bezanilla Francisco , Armstrong Clay M.
Published: October 2006

Preceding the opening of the sodium channels of axon membrane there is a small outward current, gating current, that is probably associated with the molecular rearrangements that open the channels. Gating current is reversibly blocked by three procedures that block the sodium current: (i) internal perfusion with zinc ions, (ii) inactivation of sodium conductance by brief depolarization, and (iii) prolonged depolarization.
Selective Pancreatic Enzyme Secretion due to a New Peptide Called Chymodenin
Authors: Adelson Joel W. , Rothman S. S.
Published: October 2006

Chymodenin, a peptide newly isolated from porcine duodenum, elicited a rapid threefold increase in secretion of chymotrypsinogen while increasing secretion of total protein by only about 40 percent; lipase secretion was unaffected. The pancreas appears able, under chymodenin stimulation, to rapidly alter the transport of an individual enzyme as opposed to producing en masse secretion of enzyme.
Calcium Absorption and Calcium-Binding Protein Synthesis:
Solanum malacoxylon
Reverses Strontium Inhibition
Authors: Wasserman R. H.
Published: October 2006

The ingestion of diets containing high concentrations of stable strontium inhibits calcium absorption and intestinal calcium-binding protein synthesis and, as shown by others, does so by inhibiting the conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol, the active form of vitamin D. The addition of the South American plant
Solanum malacoxylon
to strontium-containing diets counteracts the inhibitory action of dietary strontium, thereby indicating that the plant contains a factor which can mimic the action of 1,25-dihydroxycholecalciferol and representing the first such factor identified in a botanical source.
Redirection of Filial Attachments in Rhesus Monkeys: Dogs as Mother Surrogates
Authors: Mason William A. , Kenney M. D.
Published: October 2006

Rhesus infants raised from birth with their mothers, age-mates, or cloth surrogates for periods varying from 1 to 10 months were separated from these objects and placed with dogs. Contrary to previous suggestions that were consistent with the notions of a critical period for attachment formation and irreversibility of filial bonds, the monkeys formed strong and specific attachments to their canine surrogates.
Magnetic Field Observations near Venus: Preliminary Results from Mariner 10
Authors: Ness N. F. , Behannon K. W. , Lepping R. P. , Whang Y. C. , Schatten K. H.
Published: October 2006

The NASA-GSFC magnetic field experiment on Mariner 10 is the first flight of a dual magnetometer system conceived to permit accurate measurements of weak magnetic fields in space in the presence of a significant and variable spacecraft magnetic field. Results from a preliminary analysis of a limited data set are summarized in this report, which is restricted primarily to Venus encounter. A detached bow shock wave that develops as the super Alfvnic solar wind interacts with the Venusian atmosphere has been observed. However, the unique coincidence of trajectory position and interplanetary field orientation at the time of bow shock crossing led to a very disturbed shock profile with considerably enhanced upstream magnetic fluctuations. At present it is not possible to ascertain the nature and characteristics of the obstacle responsible for deflecting the solar wind flow. Far downstream disturbances associated with the solar wind wake have been observed.
Hydrogen Evolution by Nitrogen-Fixing
Anabaena cylindrica
Cultures
Authors: Benemann John R. , Weare N. M.
Published: October 2006

Actively growing, nitrogen-fixing cultures of the blue-green alga
Anabaena cylindrica
can simultaneously evolve hydrogen and oxygen from water and light. Hydrogen evolution was strongly inhibited by N
2
but only slightly by CO or O
2
, characteristics of the nitrogenase reaction in the heterocysts of
Anabaena cylindrica
. We suggest that this reaction has potential use in solar energy conversion.
Pineal β-Adrenergic Receptor: Diurnal Variation in Sensitivity
Authors: Romero Jorge A. , Axelrod Julius
Published: October 2006

The responsiveness of the pineal β-adrenergic receptor that regulates serotonin-
N
-acetyltransferase activity is nearly ten times greater at the end of the light period (0600 to 1800 hours) than at the end of the dark period (1800 to 0600 hours). These changes in sensitivity of the postsynaptic β-adrenergic receptor are related to diurnal changes in the release of noradrenaline from sympathetic nerves innervating the pineal. Supersensitivity of the receptor appears to result from decreased release of the neurotransmitter during daytime, and subsensitivity from increased release at night.
Pierce's Disease of Grapevines: Evidence for a Bacterial Etiology
Authors: Auger Jaime G. , Shalla Thomas A. , Kado Clarence I.
Published: October 2006

A Gram-positive, rod-shaped bacterium was isolated and grown in pure culture on artificial mediums from the leafhopper
Draeculacephala minerva
Ball which had fed on plants infected with Pierce's disease. The bacterial culture was injected into uncontaminated leafhoppers which were than allowed to feed on healthy grapevines. After exposure to these leafhoppers, typical symptoms of Pierce's disease developed; however, no symptoms developed on plants exposed to leafhoppers injected with sterile culture medium. The same organism was reisolated from the experimentally inoculated plants. Electron microscopic examination of these infected plants revealed bacterial cells localized in the xylem tissues. No such cells were seen in healthy or control plants.
Octopamine: Presence in Single Neurons of
Aplysia
Suggests Neurotransmitter Function
Authors: Saavedra Juan M. , Brownstein Michael J. , Carpenter David O. , Axelrod Julius
Published: October 2006

Octopamine has been identified and measured in individual neurons from
Aplysia californica
. Neither dopamine nor norepinephrine was detected in these cells. Thus, in
Aplysia
there may be separate populations of catecholaminergic and monophenolaminergic cells. Octopamine may have functions of its own in the central nervous system of mollusks.
Neuronal Analysis of Wave Form in the Time Domain: Midbrain Units in Electric Fish during Social Behavior
Authors: Scheich Henning
Published: October 2006

A fish of the genus
Eigenmannia
responds differently to a neighboring conspecific fish with a slightly higher frequency of the electric organ discharge than its own than to one with a slightly lower such frequency than its own. When the two frequencies are beating against each other the special wave shape of the electric organ discharge leads to asymmetries of the beat pattern which are distinct for the two cases. Midbrain neurons, called "ΔF decoders," recognize sign and magnitude of the frequency difference on the basis of these patterns, that is, in the time rather than the frequency domain.
Topology of the Outer Segment Membranes of Retinal Rods and Cones Revealed by a Fluorescent Probe
Authors: Yoshikami S. , Robinson W. E. , Hagins W. A.
Published: October 2006

When
N
,
N
′-didansyl cystine binds to the cell membranes of vertebrate rods and cones its fluorescence efficiency increases about 20-fold. The entire outer segments of living cones become brilliantly fluorescent. Stained live rods, as well as most freshly detached outer segments, are only weakly fluorescent, but they become brightly fluorescent within a few seconds if their plasma membranes are osmotically ruptured. The difference in staining of rod and cones suggests that disk membranes of rods are not continuous with the plasma membranes are osmotically ruptured. The difference in staining of rod and cones plasma membrane on outer segments of photoreceptors in electrophysiological and biochemical experiments, and to study the infolding pattern of rod and cone disks.
Histamine Inhibition of Neutrophil Lysosomal Enzyme Release: an H2 Histamine Receptor Response
Authors: Busse William W. , Sosman Jeffrey
Published: October 2006

Human polymorphonuclear leukocytes treated with cytochalasin B release the lysosomal enzyme beta glucuronidase during contact with serum-activated zymosan particles. Histamine increases intracellular cyclic adenosine monophosphate and inhibits release of this enzyme. The H2 antihistamine metiamide blocks the histamine inhibition of lysosomal enzyme release and the increase in the intracellular adenosine 3,5′-monophosphate of granulocytes. Chlorpheniramine, an H1 antihistamine, did not block the histamine inhibition of granulocyte lysosomal enzyme release.
Protein Purification: Adsorption Chromatography on Controlled Pore Glass with the Use of Chaotropic Buffers
Authors: Bock Hans Georg , Skene Pate , Fleischer Sidney , Cassidy Paul , Harshman Sidney
Published: October 2006

Chromatography on controlled pore glass in combination with chaotropic buffers makes possible, in a single step, protein purifications of several hundredfold. The new emphasis is on highly selective controllable adsorption. The method is useful for the purification and concentration of proteins from large volumes of complex media and for the purification of proteins that are poorly soluble or tend to aggregate in aqueous solution. D-(-)-β-Hydroxybutyrate dehydrogenase, a mitochondrial membrane-bound protein, several soluble proteins, and staphylococcal α toxin, which can be purified directly from large volumes of culture medium, are used to illustrate the method.
Urea Tolerance as a Molecular Adaptation of Elasmobranch Hemoglobins
Authors: Bonaventura Joseph , Bonaventura Celia , Sullivan Bolling
Published: October 2006

Urea is maintained at moderately high concentrations in the blood and tissues of marine elasmobranchs. Functional properties of the hemoglobins from several elasmobranch species are unaffected by urea concentrations as high as 5 molar. This insensitivity to urea, which is not observed with human hemoglobin, is accompanied by an increased sensitivity to sodium chloride.
Aversive Situational Effects on Alpha Feedback Training
Authors: Orne Martin T. , Paskewitz David A.
Published: October 2006

Anticipation of electric shock did not depress alpha activity in a feedback situation though it was associated with reported anxiety and heightened arousal indexed by greatly increased heart rate and number of spontaneous skin conductance responses. Contrary to previous reports, a reduction in alpha activity is not a necessary consequence of apprehension or heightened arousal.
World Climates and Food Supply Variations
Authors: Newman James E. , Pickett Robert C.
Published: October 2006

Most areas of famine could be greatly reduced with proper planning. Improvements in food production in nearby relatively favorable areas could alleviate the present situation whereby a disastrous food shortage must become "newsworthy" throughout the world before the ponderous machinery of international assistance and very expensive intercontinental staple grain shipments are made. Such planning would allow man to be far less at the mercy of the annual whims of seasonal weather for his food supply.