bluuebunny/crossref_metadata_2025 huggingface dataset:
Roxithromycin inhibits tumor necrosis factor‐α‐induced matrix metalloproteinase‐1 expression through regulating mitogen‐activated protein kinase phosphorylation and Ets‐1 expression
Authors: Oyama T. , Matsushita K. , Sakuta T. , Tokuda M. , Tatsuyama S. , Nagaoka S. , Torii M.
Published: October 2006

Background and Objective:  In periodontitis, matrix metalloproteinases (MMPs) are upregulated in response to locally released inflammatory cytokines, resulting in pathologic processes. Roxithromycin is a 14‐membered ring macrolide antibiotic with broad‐spectrum antibacterial effects against oral pathogens and immunomodulatory effects. Recently, we reported that roxithromycin inhibits tumor necrosis factor (TNF)‐α‐induced vascular endothelial growth factor expression in human periodontal ligament (HPDL) cell cultures. In the present study, we examined the effect of roxithromycin on TNF‐α‐induced MMP‐1 production by HPDL cells.

Material and Methods:  Cultured cells were incubated with 1% fetal bovine serum for 24 h, followed by treatment with 10 ng/ml TNF‐α, 10 µm roxithromycin, and mitogen‐activated protein kinase inhibitor at various concentrations. Culture supernatants and sediments were collected at different time‐points and used for enzyme‐linked immunosorbent assays, and northern and western blot analyses.

Results:  In HPDL cell cultures, roxithromycin strongly inhibited TNF‐α‐induced MMP‐1 mRNA expression and production. The inhibition of MMP‐1 gene expression by roxithromycin was dependent on de novo protein synthesis and was regulated at the transcriptional level. Roxithromycin significantly inhibited TNF‐α‐induced c‐Jun N‐terminal kinase activation (JNP) and marginally inhibited extracellular signal‐regulated kinase (ERK) 1/2 activation, but not p38 mitogen‐activated protein kinase activation. Furthermore, roxithromycin reduced the induction of Ets‐1, one of the critical factors in MMP‐1 transcription.

Conclusion:  Roxithromycin inhibits TNF‐α‐mediated MMP‐1 induction through the downregulation of ERK1/2 and JNK activation and the subsequent reduction of Ets‐1, suggesting that roxithromycin may have therapeutic use in periodontitis and other chronic inflammatory conditions involving MMP‐1 induction.
Electromagnetic Muscle Stretch Strongly Excites Sensorimotor Cortex Neurons in Behaving Primates
Authors: Wolpaw Jonathan R.
Published: October 2006

Responses of single units in primary motor and sensory cortex of behaving primates to electromagnetic stretch of the muscle flexor carpi ulnaris are comparable in latency and intensity to responses to wrist extension. Thus, muscle stretch appears to be a major factor in cortical response to limb displacement during performance and probably has an important role in motor control at the cortical level.
Somatostatin Suppresses Secretin and Pancreatic Exocrine Secretion
Authors: Boden Guenther , Sivitz Michael C. , Owen Oliver E. , Essa-Koumar Noorjehan , Landor John H.
Published: October 2006

Somatostatin, a hypothalamic peptide, suppresses hydrochloric acid-stimulated release of secretin, pancreatic flow rate, and bicarbonate and protein secretion in fasted, conscious dogs. It also reduces nonstimulated pancreatic exocrine secretion but does not affect basal secretin concentrations. Suppression of HCl-stimulated secretin release is complete, whereas pancreatic flow rate and bicarbonate and protein secretions are only partially inhibited. The action of somatostatin is rapid in onset and quickly reversible.
Clades versus Clones in Evolution: Why We Have Sex
Authors: Stanley Steven M.
Published: October 2006

Sexual reproduction predominates among organisms mainly because most evolutionary change is concentrated in speciation events and asexual species cannot speciate in the normal sense. Asexual clones seldom diversify rapidly enough to overcome normal rates of extinction. In contrast, phylogenetic groups of sexual species (clades) commonly develop broad, heterogeneous adaptive zones rapidly enough to ensure survival.
Breast Cancer Patients: Substance in Blood Causing Acceleration of Erythrocyte Sedimentation Rate
Authors: Riley Vernon
Published: October 2006

The frequency distribution curve of the erythrocyte sedimentation rates obtained from a population of 3523 normal females was compared with the distribution found in 544 patients with benign breast disease and that for 385 patients with carcinoma of the breast. No significant difference was found between the normal female population and patients with benign lesions of the breast. This was in contrast to the distorted distribution curve of erythrocyte sedimentation rates exhibited by the population of patients having malignant breast lesions. An unknown substance present in the blood plasma of the cancer patients appears to be responsible for the abnormal sedimentation rate phenomenon.
Human Heart and Platelet Actins Are Products of Different Genes
Authors: Elzinga M. , Maron B. J. , Adelstein R. S.
Published: October 2006

The amino acid sequences of selected cyanogen bromide peptides from human blood platelet actin and human cardiac muscle actin were compared; it was found that, at position 129, platelet actin has threonine, and that cardiac muscle actin has valine. Thus human cytoplasmic and myofibrillar actins must be synthesized under the control of different genes.
Selective Production of
cis
- and
trans
-Verbenol from (-)- and (+)-α-Pinene by a Bark Beetle
Authors: Renwick J. A. A. , Hughes P. R. , Krull I. S.
Published: October 2006

A unique biological system whereby optical isomers are selectively transformed to geometrical isomers is demonstrated in Ips paraconfusus. Exposure of adult male and female beetles to vapor of (-)-α-pinene resulted in the production of (+)-
cis
-verbenol, a pheromone of this species, whereas (+)-α-pinene was oxidized to (+)-
trans
-verbenol. It appears, therefore, that the ability of a bark beetle to produce its aggregation pheromone can be governed by the chirality of a precursor in the host tree.
Tin: A Potent Inducer of Heme Oxygenase in Kidney
Authors: Kappas Attallah , Maines Mahin D.
Published: October 2006

Tin greatly enhances heme breakdown in kidney, thus impairing heme-dependent cellular functions, such as cytochrome P-450 mediated drug biotransformation. This novel action of the metal results from a potent induction effect on heme oxygenase, the enzyme that catalyzes heme oxidation in microsomes. The possible toxicological implications of this tin effect in the kidney merit further investigation.
Eimeria tenella
(Sporozoa, Coccidia): Gametogony Following a Single Asexual Generation
Authors: McDougald L. R. , Jeffers T. K.
Published: October 2006

Selection of
Eimeria tenella
for precociousness resulted in a strain with only one asexual generation prior to gametogony.
Western Pine Beetle: Specificity Among Enantiomers of Male and Female Components of an Attractant Pheromone
Authors: Wood David L. , Browne Lloyd E. , Ewing Bland , Lindahl Kenneth , Bedard William D. , Tilden Paul E. , Mori Kenji , Pitman Gary B. , Hughes Pat R.
Published: October 2006

The flight response of both sexes of Dendroctonus brevicomis to the mixture of myrcene, racemic frontalin, and (1
R
,5
S
,7
R
)-(+)-exo-brevicomin and to the mixture of myrcene, (1
S
,5
R
)-(-)-frontalin and racemic exo-brevicomin was significantly greater than the response to the same mixtures in which the antipodes were substituted. The flight response to these two mixtures was also greater than the response to the ternary mixture of myrcene, racemic frontalin, and racemic exo-brevicomin (MFE). The walking response of both sexes to the mixture of myrcene, racemic frontalin, and (+)-exo-brevicomin was not different from the response to MFE. Substitution of the antipode lowered the response when compared to that of MFE. When evaporated with ponderosa pine turpentine, (-)-frontalin was active in the field while its antipode was not.
Ant-Aphid Association: Role of Aphid Alarm Pheromone
Authors: Nault L. R. , Montgomery M. E. , Bowers W. S.
Published: October 2006

When attacked by predators, aphids secrete alarm pheromones that cause nearby aphids to disperse. Ant-associated (myrmecophilous) aphid species disperse less readily than nonmyrmecophilous species. Ant exposure further depresses the dispersive alarm behavior of myrmecophilous species. The ant
Formica subsericea
responds to aphid alarm pheromone in a way that is beneficial to the aphid. These findings support our hypothesis that myrmecophilous aphids depend more on ants for protection from predators than on their own dispersive powers.
Electric Response of Glia Cells in Cat Brain
Authors: Tasaki I. , Chang J. J.
Published: October 2006

An experiment is described suggesting that the glia cells in the mammalian cerebral cortex are capable of developing electric responses to direct stimuli. When hyperfine microelectrodes were pushed into the cortex of a cat, slow, reversible potential variations were recorded which resembled the "electric responses" from the glia cells in tissue culture.
Solution Structure of the SH3 Domain of Src and Identification of Its Ligand-Binding Site
Authors: Yu Hongtao , Rosen Michael K. , Shin Tae Bum , Seidel-Dugan Cynthia , Brugge Joan S. , Schreiber Stuart L.
Published: October 2006

The Src homology 3 (SH3) region is a protein domain of 55 to 75 amino acids found in many cytoplasmic proteins, including those that participate in signal transduction pathways. The solution structure of the SH3 domain of the tyrosine kinase Src was determined by multidimensional nuclear magnetic resonance methods. The molecule is composed of two short three-stranded anti-parallel β sheets packed together at approximately right angles. Studies of the SH3 domain bound to proline-rich peptide ligands revealed a hydrophobic binding site on the surface of the protein that is lined with the side chains of conserved aromatic amino acids.
"Attention" Units in the Auditory Cortex
Authors: Hubel David H. , Henson Calvin O. , Rupert Allen , Galambos Robert
Published: October 2006

In the course of examining single unit responses from the cortex of unrestrained and unanesthetized cats, we have come upon a population of cells that appears to be sensitive to auditory stimuli only if the cat "pays attention" to the sound source. We have described these responses, since they have not been previously reported and since they illustrate an important difference between the information which can be gleaned from experiments of this type and that obtained in the usual "acute" microelectrode experiment.
Gibberellin-Induced Inhibition of Bud Development in Some Species of
Prunus
Authors: Bradley Muriel V. , Crane Julian C.
Published: October 2006

Development of both floral and vegetative buds was inhibited by application of gibberellin to branches of
Prunus
species. The development of the lateral meristem was blocked, in general, through inhibition of mitosis, while, concurrently, the growth of certain other plant organs was stimulated in some cases. That higher dosages were required to block vegetative than floral bud growth suggests that gibberellin also exerts the more specific effect of inhibiting floral initiation.
Fusion of Complex Flicker II
Authors: Levinson J.
Published: October 2006

Flicker waveform has been found to have a slight but specific effect upon fusion threshold. A depression of threshold amplitude of about 30 percent occurs if a second harmonic of near-threshold amplitude is added to the fundamental. The magnitude of the depression depends critically on the relative phase of the two components of the waveform.
Uptake of Glucose from Solution by the Solitary Coral,
Fungia
Authors: Stephens Grover C.
Published: October 2006

The removal of glucose from solution in sea water by the coral,
Fungia
, has been followed with D-glucose-C
14
. From 15 to 37 percent of the sugar in 200 ml of solution is taken up per hour from concentrations of 1 to 40 mg/liter. This rate of uptake provides sufficient material to account for the maintenance metabolism of the coral at sugar concentrations of 3.75 to 7.25 mg/liter.
Analysis of Firing Patterns in Single Neurons
Authors: Gerstein George L.
Published: October 2006

The use of a high-speed digital computer for investigation of neural firing patterns is described. The high sensitivity of the method permits detection of stimulus-response relations buried in a background of spontaneous activity.
Telemetering of Intraenteric Pressure in Man by an Externally Energized Wireless Capsule
Authors: Farrar John T. , Berkley Carl , Zworykin Vladimir K.
Published: October 2006

Gastrointestinal intraluminal pressures have been recorded in eight patients by a pressure-sensitive telemetering capsule energized by an external, wireless source. The capsule is smaller and simpler than a battery-powered capsule, and has a relatively unlimited life. The pressure records are similar to those obtained by other sensing devices.
Gating of the Cardiac Ca
2+
Release Channel: the Role of Na
+
Current and Na
+
-Ca
2+
Exchange
Authors: Sham James S. K. , Cleemann Lars , Morad Martin
Published: October 2006

In cardiac myocytes, calcium influx through the calcium channel is the primary pathway for triggering calcium release. Recently it has been suggested that the calcium-induced calcium release mechanism can also be activated indirectly by the sodium current, which elevates the sodium concentration under the cell membrane, thereby favoring the entry of "trigger" calcium via the sodium-calcium exchanger. To test this hypothesis, sodium current was suppressed by reducing the external sodium concentration or applying tetrodotoxin. At potentials positive to -30 millivolts, calcium release was unaffected. A small calcium release at more negative potentials could be attributed to partial activation of calcium channels, because it was unaltered by replacement of sodium with lithium and was blocked by cadmium. Thus, sodium influx or its accumulation does not initiate calcium release. In addition, sodium-calcium exchange-related calcium release at potentials positive to +80 millivolts has slower kinetics than calcium channel-induced release. Therefore, only the calcium channel gates the fast release of calcium from the sarcoplasmic reticulum in the range of the action potential.
Flow-Dependent Cytosolic Acidification of Vascular Endothelial Cells
Authors: Ziegelstein Roy C. , Cheng Linda , Capogrossi Maurizio C.
Published: October 2006

Hemodynamic shear stress affects endothelial cell structure and function, but little is known about the signal transduction mechanisms involved in these processes. The effect of laminar shear stress on cytosolic pH (pH
i
) was examined in rat aortic endothelial cells cultured in glass capillary tubes. Shear stress forces led to a rapid decrease in pH
i
(maximal effect 0.09 pH unit at 13.4 dynes per square centimeter). Removal of specific ions or addition of exchange inhibitors suggests that in vascular endothelial cells shear stress forces activate both an alkali extruder, sodium ion-independent chloride-bicarbonate ion exchange, and an acid extruder, sodium-hydrogen ion exchange; the net effect in physiologic buffer with the bicarbonate ion is a decrease in pH
i
.
Retinoids Selective for Retinoid X Receptor Response Pathways
Authors: Lehmann Jürgen M. , Jong Ling , Fanjul Andrea , Cameron James F. , Lu Xian Ping , Haefner Pamela , Dawson Marcia I. , Pfahl Magnus
Published: October 2006

Retinoids have a broad spectrum of biological activities and are useful therapeutic agents. Their physiological activities are mediated by two types of receptors, the retinoic acid receptors (RARs) and the retinoid X receptors (RXRs). RARs, as well as several related receptors, require heterodimerization with RXRs for effective DNA binding and function. However, in the presence of 9-
cis
-retinoic acid, a ligand for both RARs and RXRs, RXRs can also form homodimers. A series of retinoids is reported that selectively activates RXR homodimers but does not affect RAR-RXR heterodimers and thus demonstrates that both retinoid response pathways can be independently activated.
Intrinsic Barriers to Dispersal in Checkerspot Butterfly
Authors: Ehrlich Paul R.
Published: October 2006

Capture-recapture studies revealed that the checkerspot butterfly
Euphydryas editha
is extraordinarily sedentary. Since no physical barriers prevent interchange between various portions of the study colony, it is concluded that intrinsic factors play the major role in limiting movement. The few available data on dispersal are discussed.
Foam Fractionation with Reflux
Authors: Lemlich Robert , Lavi Elias
Published: October 2006

A surface-active aqueous solution was foamed up a glass column, removed, collapsed, and returned as down-coming liquid to drain countercurrently against the rising foam. This deliberate refluxing action greatly increased the degree of separation of the surfactant over that obtainable without reflux. The effects of altering the gas rate and the solute concentration were also studied.
Axenic Cultivation of
Entamoeba histolytica
Authors: Diamond Louis S.
Published: October 2006

Entamoeba histolytica
(National Institutes of Health strain 200) has been maintained in axenic culture through 50 transfers over a period of 6 months. The medium used is diphasic and contains a cell-free extract of chick embryo which is essential for growth. Inocula of 50,000 amoebas yield 150,000 to 200,000 organisms in 72 hours of incubation at 35°C. An extract prepared from boiled embryos supports growth equally well.
Potassium Deficiency in Marmots during Hibernation
Authors: Christian John J.
Published: October 2006

Semiquantitation of potassium deficiency in the renal papillae indicates that woodchucks (
Marmota monax
) are deficient in potassium annually during the time they subsist on stored fats. The deficiency begins prior to hibernation, progresses during hibernation, and, in males, continues during the immediate postemergence period.
Influence of Suggestion and Subjects' Prior Knowledge in Research on Sensory Deprivation
Authors: Jackson C. Wesley , Kelly E. Lowell
Published: October 2006

Several investigators have reported that normal human subjects placed in a dark, quiet room for several hours undergo a variety of hallucinatory experiences; these are typically attributed to extended periods of reduced sensory input. In the present experiment, similarly dramatic subjective experiences occurred within 1 hour when subjects were told of the possibility and appropriateness of such phenomena.
Isomerase and Chaperone Activity of Prolyl Isomerase in the Folding of Carbonic Anhydrase
Authors: Freskgård Per-Ola , Bergenhem Nils , Jonsson Bengt-Harald , Svensson Magdalena , Carlsson Uno
Published: October 2006

Several proteins have been discovered that either catalyze slow protein-folding reactions or assist folding in the cell. Prolyl isomerase, which has been shown to accelerate rate-limiting
cis-trans
peptidyl-proline isomerization steps in the folding pathway, can also participate in the protein-folding process as a chaperone. This function is exerted on an early folding intermediate of carbonic anhydrase, which is thereby prevented from aggregating, whereas the isomerase activity is performed later in the folding process.
Cosmogenic Carbon-14 in Meteorites and Terrestrial Ages of "Finds" and Craters
Authors: Goel Parmatma S. , Kohman Truman P.
Published: October 2006

Carbon-14 has been measured in several stone and iron meteorites. For "falls," the C
14
/Al
26
ratios in stones and the C
14
/Cl
36
ratios in irons are consistent with constant irradiation. The stone "finds" have radiocarbon ages of up to ≥ 21,000 years. The Henbury craters are apparently ≤ 7,000 and the Odessa craters ≥ 11,000 years old.
Radiotelemetry of the Respiration of a Flying Duck
Authors: Lord Rexford D. , Bellrose Frank C. , Cochran William W.
Published: October 2006

Respirations of a flying wild mallard duck,
Anas platyrhynchos
, appear to be synchronized with wing beat in a ratio of 1 to 2. Wing beats come during exhalation and between respirations. The average number of respirations was 14 per minute for a resting duck and 96 per minute for a flying duck.
Contamination of Vegetation by Tetraethyl Lead
Authors: Cannon Helen L. , Bowles Jessie M.
Published: October 2006

Tetraethyl lead is a normal constituent of vegetation growing along our highways. Washed grass near Denver contained 3000 ppm (in ash) near major intersections and > 50 ppm for 500 feet downwind. Vegetables grown within 25 feet of a road in upstate New York and western Maryland averaged 80 to 115 ppm.
Revision of Aleutian Prehistory
Authors: Laughlin W. S. , Reeder W. G.
Published: October 2006

Exposure to x-rays of low intensity immediately arouses the sleeping rat. Activation of the central nervous system, indicated by behavioral and heart rate responses, depends upon the rate but not the dose of exposure. The arousal reaction is not dependent upon direct visual stimulation. The nervous system is probably directly sensitive to ionizing radiation.
Huntington's Disease: Delayed Hypersensitivity in Vitro to Human Central Nervous System Antigens
Authors: Barkley David S. , Hardiwidjaja Steven , Menkes John H.
Published: October 2006

Huntington's disease is a hereditary, chronic, degenerative disease of the brain which is transmitted by an autosomal dominant gene. We have discovered that lymphocytes from patients with Huntington's disease respond to the presence of brain tissue from patients with the disease by producing migration inhibition factor, a correlate of the cellular immune response. Lymphocytes from donors without the disease do not respond to the diseased brain tissue, and lymphocytes from patients with Huntington's disease respond only rarely to brain tissue from donors without the disease.
Adjustment of Monkeys to Five Continuous Days of Work
Authors: Byck Robert , Hearst Eliot
Published: October 2006

The efficiency of well-trained monkeys improved after repeated exposures to a prolonged task. This result suggests that resistance to fatigue may be increased by prior experience with the fatiguing situation.
Two Meteorites of Unusually Short Cosmic-Ray Exposure Age
Authors: Anders Edward
Published: October 2006

The chondrites Cold Bokkeveld and Farmington seem to have reached the earth less than 200,000 years after they left their parent body. Either these meteorites came from the moon, or, more probably, the collision life times of interplanetary objects are occasionally much shorter than has been assumed heretofore.
Hypersexual Activity Induced in Females of the Cockroach
Nauphoeta cinerea
Authors: Roth Louis M.
Published: October 2006

Corpora allata control mating in females principally by inducing feeding on the tergum of a displaying male. Mating induces an inhibitory nervous mechanism, the seat of which is posterior to the last abdominal ganglion, causing an immediate loss of receptivity by suppressing feeding behavior. After parturition, females may again be receptive. Transection of the nerve cord before or just after mating causes excessive sexual behavior.
Xenon Tetrafluoride: Crystal Structure
Authors: Ibers James A. , Hamilton Walter C.
Published: October 2006

On the basis of a three-dimensional x-ray analysis, the xenon tetrafluoride molecule in the solid is planar; the approximate symmetry is
D

4
h

. The average distance between the xenon and the fluorine is 1.92 ± 0.03 Å.
Submergence of the Connecticut Coast
Authors: Bloom Arthur L. , Stuiver Minze
Published: October 2006

Radiocarbon-dated samples show that the Connecticut coast has submerged about 9 feet in the last 3000 years and about 33 feet in the last 7000 years. The rate of submergence is similar to rates reported from other coasts. The finding strengthens the hypothesis that a worldwide postglacial rise of sea level is the cause.
Christmas Factor: Dosage Compensation and the Production of Blood Coagulation Factor IX
Authors: Frota-Pessoa O. , Gomes E. L. , Calicchio Therezinha R.
Published: October 2006

The amount of factor IX (Christmas factor) for different genotypic classes was determined by means of a variant of the thromboplastin generation test. The mean value for females heterozygous for the Christmas gene was about half the mean values for normal males and for normal homozygous females; means for the latter two groups were about equal. This dosage compensation is interpreted as evidence in support of Lyon's hypothesis, according to which one X chromosome is inactive in mammalian females.
Heritability of Variations in Oil Content of Individual Corn Kernels
Authors: Bauman L. F. , Conway T. F. , Watson S. A.
Published: October 2006

Nuclear magnetic resonance spectroscopy was used to determine oil content of individual corn kernels in order to evaluate this technique as an aid in the development of strains having greater oil content. This method is rapid and does not impair viability. Individual kernels from a selfed single-cross ear ranged from 2.7 to 5.4 percent oil and were significantly correlated (
r
= +0.75) with the oil content of their progeny ears. This indicates that the single-kernel differences in oil content were heritable, and this method may greatly increase selection efficiency in breeding for higher oil content in corn.
Crystal Structures at High Pressures of Metallic Modifications of Compounds of Indium, Gallium, and Aluminum
Authors: Jamieson John C.
Published: October 2006

X-ray diffraction shows that the high-pressure modifications (at 22 to 130 kilobars) of the antimonides of indium, gallium, and aluminum are analogous to white tin. The arsenide and phosphide of indium transform to NaCl type. The transformation of these semiconductors to their metallic states is empirically related to their energy gap under normal conditions.
On Biochemical Variability and Innovation
Authors: Cohen Seymour S.
Published: October 2006

Examples of variability and apparent innovation presented in this paper are but a portion of the many examples in the literature. Thus, the notion of the "unity of biochemistry" has been advanced in an overly simplified form and reflects a primitive stage in the development of the discipline. Cells contain many more compounds and biosynthetic mechanisms than we had suspected or list in our texts. Accordingly, either early chemical evolution was far more extensive than we have postulated or an evolution of biochemical synthesis and function took place which was more extensive than has been postulated; perhaps both have occurred. The chemical choices available from the environment have been considerable rather than limited and the cells have chosen, adapted, improved upon a limited number of these, and in turn have themselves been selected. In the case of the naturally occurring antibiotic substances, biosynthetic mechanisms for compounds which do not fit within the cells' own nucleic acids and proteins to advantage have nevertheless been preserved since they contribute to survival. On the other hand, some of these compounds such as α-ribazole, are fitted to other metabolic uses. The existence of the large number of uncommon relatives of the common components of the nucleic acids and proteins in turn implies an enormous untapped area of potential knowledge concerning their paths of biosyntheses and the genetic and physiological controls for these same paths. That these compounds exist perhaps also indicates an expanded material basis for a continuing biochemical evolution.
Conditioning of a Free Operant Response in Planaria
Authors: Lee Richard M.
Published: October 2006

The response of breaking a photoelectric cell beam was automatically recorded and reinforced. Termination of an intense light was the reinforcement in an escape conditioning situation. The rate of response for the experimental subjects was significantly different from that of controls matched for equivalent changes in light intensity.
Carbon Isotope Abundance in Meteoritic Carbonates
Authors: Clayton Robert N.
Published: October 2006

The C
13
/C
12
ratio in the carbonate minerals of Orgueil, a carbonaceous chondrite, is 6 percent greater than the ratio in any known terrestrial carbon. The effect may be produced by a chemical isotope fractionation involving processes not common on earth, or it may be the result of incomplete homogenization of substances with different histories of nucleosynthesis.
Geochronology
Authors: Tilton G. R. , Hart S. R.
Published: October 2006

In summary, it now seems possible to obtain accurate ages for many of the common rock types. When rocks have been affected by metamorphic episodes after the time of crystallization, it is possible to recognize this from the age values and, in some cases, to date both the time of crystallization and the time of metamorphism. Work is under way that will make it possible to draw accurate geochronological maps of the continents. An impressive regularity is already evident in the map for North America. Knowledge of the temporal and areal distribution of ages should have an important bearing on theories of the origin of continents and of mountain-building processes.
Erosion and Deposition of Italian Stream Valleys During Historic Time
Authors: Judson Sheldon
Published: October 2006

The recent geologic history of small streams in east-central Sicily and southern Etruria has been dated archeologically. In Sicily a period of deposition began post 8th century B.C. and had ended by 325 B.C. After a period of erosion, another, less extensive, alluviation took place, probably in medieval time. North of Rome in southern Etruria an alluviation that began no earlier than the late Roman empire probably continued into medieval time.
Underwater Sounds of Pinnipeds
Authors: Schevill William E. , Watkins William A. , Ray Carleton
Published: October 2006

Descriptions and analyses are presented of underwater sounds made by six species of seals in captivity,
Zalophus californianus
,
Phoca vitulina
,
P. (Pusa) hispida
,
P. (Pagophilus) groenlandica
,
Halichoerus grypus
, and
Cystophora cristata
. The suitability of these very faint sounds for echolocation is discussed.
Rank of Mothers and Sons in Bands of Rhesus Monkeys
Authors: Koford Carl B.
Published: October 2006

In bands of free-ranging macaques, adolescent males typically leave their mothers in the central part of the band and assume low social rank at the periphery. But the adolescent sons of high-ranking mothers may remain central and rise to high rank without becoming peripheral.
Apatite: Origin of Blue Color
Authors: Johnson P. D. , Prener J. S. , Kingsley J. D.
Published: October 2006

The optical absorption and emission spectra of natural blue apatite are similar enough to spectra of synthetic compounds containing MnO
4
-3
to conclude that the blue color of natural apatite results from the presence of this ion.
Cortisol from Human Nerve
Authors: Touchstone Joseph C. , Griffin James E. , Kasparow Maria
Published: October 2006

Cortisol was found in myelinated nerve fibers of the lumbosacral plexus (2.0 to 6.0 μg per gram of tissue) and in the sympathetic chain with dorsal root ganglia (0.2 to 0.4 μg per gram of tissue).
Weighing Naked Proteins: Practical, High-Accuracy Mass Measurement of Peptides and Proteins
Authors: Chait Brian T. , Kent Stephen B. H.
Published: October 2006

Two new technologies have made the study of proteins by mass spectrometry straightforward. Proteins with molecular masses of up to more than 100 kilodaltons can be analyzed at picomole sensitivities to give simple mass spectra corresponding to the intact molecule. This development has allowed unprecedented accuracy in the determination of the molecular weights of proteins. A number of "case studies" are used to present the revolutionary impact that these powerful new ways of looking at proteins are having on biological research.
Lipoprotein Movement through Canine Aortic Wail
Authors: Duncan Leroy E. , Buck Katherin , Lynch Almorris
Published: October 2006

Low-density (1.019 to 1.063) lipoprotein labeled with radioiodine enters the inner layer of the canine aortic wall directly from the aortic lumen. Its rate of entry is greatest in the proximal aorta and decreases progressively down the length of the aorta. A similar gradient was observed previously for the accumulation of cholesterol early in experimental atherosclerosis.
Mice Reared with Rats: Modification of Behavior by Early Experience with Another Species
Authors: Denenberg Victor H. , Hudgens Gerald A. , Zarrow M. X.
Published: October 2006

Mice in group 1 (controls) spent all their lives with other mice. Mice in group 2 had experience only with male and female rats after weaning; group 3 mice had no experience with peers—each litter was reduced to one pup, which was reared in isolation after weaning; group 4 mice were fostered to a lactating rat mother at approximately 3 days of age and thereafter lived only with rats. In adulthood group 4 mice were the least active and group 3 the most; mice in groups 2 and 4 preferred to spend time in a chamber adjacent to a rat, those from groups 1 and 3 in a chamber containing another mouse; when mice were paired off within experimental groups and given the opportunity to fight each other, the percentage of pairs in which fights occurred for groups 1, 2, 3, and 4 were, respectively, 44, 27, 100, and 0.
Nitrous Oxide Produced by the Catalytic Oxidation of Organic Nitrogen Compounds
Authors: Christian Jack G.
Published: October 2006

Nitrous oxide is produced by the catalytic oxidation of organic nitrogen compounds of several distinct structural types with Hopcalite catalyst at a space velocity of 21,000 hours
-1
and at temperatures near 300°C.
Sea Level Changes in the Past 6000 Years: Possible Archeological Significance
Authors: Shepard Francis P.
Published: October 2006

Evidence from many stable areas indicates that sea level has risen slowly during the past 6000 years, with a total change of about 6 meters. Since the same period is also important in the history of man, the rise in sea level explains the widespread submergence of building sites and other human relics along coasts where ancient man lived.
Infrared Emission Spectra of Organic Solids from 5 to 6.6 Microns
Authors: Hovis W. A.
Published: October 2006

The emission spectra of thin layers of a number of organic solids have been studied from 5 to 6.6 μ in the infrared to determine if there are specific emission characteristics that would allow identification of such solids as organic. This was the case only for very thin films with strong absorption bands.
Autoradiographic Distribution of Radioactive Sodium in Rat Kidney
Authors: Mercer Paul F. , Wasserman R. H.
Published: October 2006

Autoradiographs of kidney sections from rats injected with sodium-22 showed two areas of relatively high concentration of the radioisotope. The first area appeared in the outer medulla; the second appeared as an area of increasing concentration toward the papilla. Autoradiographs of sections labeled with chloride-36 appeared essentially the same. Autoradiographs of sections labeled with inulin-C
14
OOH showed an increased concentration in the inner medulla. These results may have a bearing on the counter-current multiplier hypothesis for the production of concentrated urine.
Light Adaptation Kinetics: The Influence of Spatial Factors
Authors: Battersby William S. , Wagman Irving H.
Published: October 2006

Reducing the target diameter of an adapting (conditioning) flash of light results in a progressive rise in the conventional light adaptation curve, as measured with a small superimposed test flash presented at the end of adapting flashes of variable duration. When both targets are the same size, an abrupt and marked rise in threshold is obtained, resulting from a unique effect that occurs near the termination of the adapting flash. This effect can be demonstrated by means of a variable delay procedure, and it indicates that neural as well as photochemical processes limit the time course of light adaptation.
Gonadal Dosages in Investigative Radiography
Authors: Garn Stanley M. , Silverman Frederic N. , Davis Ann A.
Published: October 2006

Using radiation-sparing and radiation-limiting techniques, gonadal (skin) dosages in the course of investigative radiography averaged under 0.3 milliroentgen for a set of radiographs, a value less than the irreducible background dosage for 1 day.
Moisture Release from Cut Alfalfa
Authors: Byers G. L. , Routley D. G. , Colburn M. W.
Published: October 2006

Mechanical treatment of alfalfa to increase its drying rate is of only limited value because little damage is done to the cellular organization. Killing the plant material with steam markedly increases the drying rate by modifying the permeability of the cuticle or cell membrane, and this may have practical significance in forage preservation.
Persistence of Bacteria in "Protoplast" Form after Apparent Cure of Pyelonephritis in Rats
Authors: Guze Lucien B. , Kalmanson George M.
Published: October 2006

Appropriate antibiotic treatment of experimental enterococcal pyelonephritis in the rat appears to effect the removal of the infecting organisms from the kidney, as judged by the culturing of kidney homogenates on standard bacteriological media. When the homogenates were cultured on media containing 0.3
M
sucrose, osmotically stabilized, it was demonstrated that bacteria were present in the "protoplast" form, and that this form persisted in the kidney for at least 13 weeks after therapy.
X-ray Diffraction Study of a DNA Which Contains Uracil
Authors: Langridge Robert , Marmur Julius
Published: October 2006

Three-dimensional structure of DNA from PBS2 bacteriophage, which contains uracil in place of the more usual thymine, is the same as that of "normal" DNA. The difference in secondary structure between DNA and RNA thus appears to be due to the 2′-hydroxyl group alone.
Lower Limit of Water Availability to Plants
Authors: Gardner W. R. , Nieman R. H.
Published: October 2006

Measurements of transpiration, cell division, and cell enlargement show that no single lower limit of available water can be defined for these three plant processes. The soil-water content at which permanent wilting is exhibited does not represent a true lower limit for any of these.
Calcite-Aragonite Equilibrium at 100°C
Authors: Crawford William A. , Fyfe William S.
Published: October 2006

The equilibrium pressure of the calcite-aragonite transition has been determined near 100°C and is 4.35 kilobars. These data are in agreement with earlier work but conflict with the most recent determination by Simmons and Bell.
Late Eocene Multituberculates and Other Mammals from Wyoming
Authors: Robinson Peter , Black Craig C. , Dawson Mary R.
Published: October 2006

Isolated teeth of multituberculates have been found in association with late Eocene fossil mammals. Previous studies reported that multituberculates were not found in deposits younger than early Eocene age (Graybull provincial substage or equivalents). This newly found occurrence indicates that these animals are more likely to be late Eocene in age than reworked early Eocene materials.
Glucose Transfer from Adenosine Diphosphate-Glucose to Starch in Preparations of Waxy Seeds
Authors: Nelson Oliver E. , Tsai Chia Yin
Published: October 2006

Preparation of starch granules from the developing seeds of 17 different waxy mutants of maize all transfer glucose from adenosine diphosphate-glucose to starch at about one-tenth of the rate of similar preparations from seeds of non-waxy maize. The source of most, if not all, of the activity in preparations from waxy mutants is a limited number of enzymatically active starch granules from the embryo and maternal tissue of the seed. All starch granules in these tissues appear to be enzymatically active. The endosperm which is the site of most starch synthesis and storage is apparently devoid of transferase activity.
Venom and Venom Apparatus of the Bull Ant,
Myrmecia gulosa
(Fabr.)
Authors: Cavill G. W. K. , Robertson Phyllis L. , Whitfield F. B.
Published: October 2006

The venom of
Myrmecia gulosa
(Myrmeciinae, Formicidae) is of a proteinaceous type and is separated by electrophoresis into eight components. The venom contains histamine, a hyaluronidase, and a direct hemolytic factor. It also shows kinin-like activity. In structure the venom apparatus is found to be massively formed internally as well as externally. It is distinguished from the apparatus of representatives of other ant subfamilies by characteristics of the free gland filaments, the reservoir wall, the intra-reservoir glandular area, and the accessory gland.
Silicon Oxynitride: A Meteoritic Mineral
Authors: Andersen Christian A. , Keil Klaus , Mason Brian
Published: October 2006

Silicon oxynitride, a new mineral, has been discovered in the Jajh deh Kot Lalu enstatite chondrite. Nitrogen and oxygen have been measured quantitatively with an electron microprobe by means of prototypes of newly developed curved crystal detection systems. X-ray diffraction patterns were obtained from silicon oxynitride separated from the meteorite and from synthetic Si
2
N
2
O.
Puromycin Effect on Memory Fixation in the Goldfish
Authors: Agranoff Bernard W. , Klinger Paul D.
Published: October 2006

Puromycin injected intracranially into the goldfish produces impairment of memory for a shock-avoidance response. Intracranial injection of puromycin aminonucleoside, or of saline has no effect. Puromycin does not affect performance in naive or overtrained goldfish.
Marshes Prograding in Oregon: Aerial Photographs
Authors: Johannessen Carl L.
Published: October 2006

When nearly circular clumps of vegetation abound in aerial photographs of mud flats in estuaries in regions of temperate climate the indication is that the marsh is expanding rapidly.
Recognizing the Emergence of Man
Authors: Ascher Robert , Ascher Marcia
Published: October 2006

Recognition of early human industries takes on significance with the realization that commitment to tools is the novel adaptive design accounting for the emergence of man. The most abundant evidence for the emergence of man consists of the stones that he refashioned. But recognizing these objects is a problem, as they are both rare and similar to the stones of the environments in which they occur. Because the validity of a procedural, or course-of-action, approach to the problem of recognition can be demonstrated, such an approach is preferable to the intuitive and heuristic approaches that have dominated attempts to deal with the possible traces of early man.
Optical Second-Harmonic Generation in Crystalline Amino Acids
Authors: Rieckhoff Klaus E. , Peticolas Warner L.
Published: October 2006

Optically active amino acids contain many highly efficient optical second-harmonic generators. When light from a ruby laser at 6943 Å falls on the crystalline amino acids with sufficient intensity, the second harmonic of the light at 3471 Å can be observed. Although the symmetry requirements for optical second-harmonic generation are always met by isomerically pure optically active substances, there is considerable variation in efficiency for the generation of the second harmonic, ranging from almost zero to greater than that of potassium dihydrogen phosphate, the most efficient known.
Intermolecular Forces in Association of Purines with Polybenzenoid Hydrocarbons
Authors: Pullman Bernard , Claverie Pierre , Caillet Jacqueline
Published: October 2006

The interactions in solution between purine or pyrimidine bases and polybenzenoid aromatic hydrocarbons probably consist in a vertical, stacking-type physical association. By molecular orbital calculations the role of the Van der Waals-London intermolecular forces in these interactions is determined. The electrostatic dipole-dipole forces are negligible, the polarization (or induction) dipole-induced dipole forces are contributory, but most important are the dispersion (or fluctuation) forces. This loose, physical type of interaction should not show any specificity with respect to the carcinogenic activity of the hydrocarbons.
Viscosities of Liquid Sodium and Potassium, from Their Melting Points to Their Critical Points
Authors: Grosse Aristid V.
Published: October 2006

The viscosities of liquid sodium and potassium were estimated up to the critical temperatures according to the method recently described for mercury. The critical absolute viscosity of sodium is 0.072 centipoise and that of potassium 0.055 centipoise, the estimated precision being plus or minus 0.01 centipoise. The critical absolute viscosities of metals are higher than those of covalent or homopolar substances of van der Waals type.
Electrical Connections between Visual Cells in the Ommatidium of
Limulus
Authors: Smith T. G. , Baumann F. , Fuortes M. G. F.
Published: October 2006

When microelectrodes are inserted in two cells of the same ommatidium in
Limulus
, current applied through the membrane of one cell produces a change in potential across the membrane of both cells. The large spikes recorded from one cell and the small spikes recorded from the other always appear synchronously. However, the small spikes are abolished selectively during the hyperpolarizing response. The discrete waves recorded from eyes adapted to darkness occur simultaneously in cells of the same ommatidium.
Probability-Learning by the Turtle
Authors: Kirk Kathleen L. , Bitterman M. E.
Published: October 2006

Tested in a two-choice situation, the painted turtle,
Chrysemys picta picta
, shows random probability-matching in visual problems and in confounded visual-spatial problems, but only maximizing or nonrandom matching (reward-following) in spatial problems. The results are compared with those of analogous experiments on fish, bird, and mammal.
Lizard Reproduction: Refractory Period and Response to Warmth in
Uta stansburiana
Females
Authors: Tinkle Donald W. , Irwin Louis Neal
Published: October 2006

Photoperiod does not affect timing of the female reproductive cycle in
Uta stansburiana.
This lizard is refractory to reproduction until early December. Later, prolonged warmth under laboratory conditions initiates the reproductive cycle in some lizards regardless of photoperiod.
Biochemical Polymorphism in Ants
Authors: Law John H. , Wilson Edward O. , McCloskey James A.
Published: October 2006

Ants of different sexes and castes produce different odorous compounds. In
Pheidole fallax
Mayr, soldier ants produce an indole base, probably skatole, whereas minor workers produce a trial substance, Males of certain species of
Lasius
and
Acanthomyops
produce mixtures of terpenes and an indole base. These mixtures are discharged during mating flights and probably are used as mating pheromones. The terpene mixtures are qualitatively similar, but each species produces a blend of distinctive proportions. Citronellol and 2,6-dimethyl-5-hepten-1-ol have been identified in the mixtures by gas chromatography and mass spectrometry.
Recombination in Bacteriophage T4: a Mechanism
Authors: Simon E.
Published: October 2006

Genetic recombination between
r
II mutants of T4 bacteriophage grown in
Escherichia coli
can occur under conditions where DNA synthesis is strongly inhibited by 5-fluorodeoxyuridine. The small amount of DNA synthesized under these conditions cannot account for the observed frequency of recombinants. The major mechanism of recombination in this system is a process of breakage and rejoining.
Trans-Aconitic Acid in Range Grasses in Early Spring
Authors: Burau R. , Stout P. R.
Published: October 2006

trans
-Aconitate ion, an inhibitor of the tricarboxylic acid cycle, was identified in range grasses as
trans
-aconitic acid, which was isolated in crystalline form. It occurs in surprisingly high concentrations in early-season forage grasses. Dry-weight concentrations of
trans
-aconitate vary with season and species; concentrations of between 1 and 2.5 percent are common in mixed pasture grasses, but are higher in certain species such as
Hordeum leporinum
(3.5 percent) and
Phalaris tuberosa
var.
stenoptera
(4.2 percent). Leaves of western larkspur (
Delphinium hesperium
) contain 12.2 percent
trans
-aconitate.
trans
-Aconitate may be partially responsible for nutritional disorders, such as grass tetany (hypomagnesemia), that occur in grazing cattle in early spring.