bluuebunny/crossref_metadata_2025 huggingface dataset:
Vocal Exchanges between Dolphins
Authors: Lilly John C. , Miller Alice M.
Published: October 2006

Observations of the vocal exchanges of bottlenose dolphins under various conditions are presented. Experimental conditions under which isolated emissions from each animal of a pair are separately recorded and in which the distance between the rostrum and the hydrophone is controlled are described. The exchanges consist of vocal alternations (
A
, then
B
, then
A
, and so on), "duets" (
A
plus
B
simultaneously), and long "solos" or "monologues." The emissions exchanged are: (i) whistles alone; (ii) slow click trains alone; (iii) simultaneous whistles and clicks from either or both animals; and (iv) squawks, quacks, blats, and so on, alone or simultaneously with whistles. Any or all of these sounds may occur in a given period. The significant carriers of meaning are to be determined. (Suggestions include various functions of relative amplitudes, absolute and relative frequency, frequency modulations, phase-shift variations, and durations of whistle emissions.) Average and peak amplitudes (at the rostrum) of each class of sound cover at least a 100-decibel range (controlled by the dolphin).
G
z
-Mediated Hormonal Inhibition of Cyclic AMP accumulation
Authors: Wong Yung H. , Conklin Bruce R. , Bourne Henry R.
Published: October 2006

Hormones inhibit synthesis of adenosine 3′,5′-monophosphate (cAMP) in most cells via receptors coupled to pertussis toxin (PTX)-sensitive guanine nucleotide-binding (G) proteins. Mutationally activated α subunits of G
i2
(α
i2
) constitutively inhibit cAMP accumulation when transfected into cells. Cells have now been transfected with mutant α subunits of four other G proteins—G
z
, a PTX-insensitive G protein of unknown function, and G
i1
, G
i3
, and G
o
, which are PTX-sensitive. Mutant α
z
, α
i1
, and α
i3
inhibited cAMP accumulation but α
o
did not. Moreover, expression of wild-type α
z
produced cells in which PTX did not block hormonal inhibition of cAMP accumulation. Thus, G
z
can trigger an effector pathway in response to hormone receptors that ordinarily interact with PTX-sensitive G
i
proteins.
Arlington Springs Man
Authors: Orr Phil C.
Published: October 2006

Bones of a man were found at a depth of 37 feet in waterlaid sediments on Santa Rosa Island, California, and dated by radiocarbon at 10,000 years before the present (B.P.). Two later occupational levels are dated at 7350 and 2090 years B.P. No artifacts are associated with the oldest bones, which are believed to be an accidental burial on the edge of a cienaga.
Differential Display of Eukaryotic Messenger RNA by Means of the Polymerase Chain Reaction
Authors: Liang Peng , Pardee Arthur B.
Published: October 2006

Effective methods are needed to identify and isolate those genes that are differentially expressed in various cells or under altered conditions. This report describes a method to separate and clone individual messenger RNAs (mRNAs) by means of the polymerase chain reaction. The key element is to use a set of oligonucleotide primers, one being anchored to the polyadenylate tail of a subset of mRNAs, the other being short and arbitrary in sequence so that it anneals at different positions relative to the first primer. The mRNA subpopulations defined by these primer pairs were amplified after reverse transcription and resolved on a DNA sequencing gel. When multiple primer sets were used, reproducible patterns of amplified complementary DNA fragments were obtained that showed strong dependence on sequence specificity of either primer.
Martian Biology
Authors: Salisbury Frank B.
Published: October 2006

Of all the proposals put forth to account for the observed Martian phenomena, the idea of life on Mars seems to be the most tenable. And if this idea is accepted, we are immediately drawn to the conclusion that this life is a very well-adapted and flourishing one—not the struggle for existence so often suggested in light of the obvious difficulties earthly organisms would have in living on Mars. The suggested criteria seem to eliminate all the known life forms, but of all these forms, a higher plant would require the least modification in order to meet the criteria. The basic shape of the leaf of a higher plant seems suited to conditions on Mars, but the lower gravity might well result in some interesting modifications in morphology. Some life forms on Mars might resemble our own higher plants, but we should be prepared to encounter some interesting surprises in biochemistry.
Double Visual Learning in Split-Brain Monkeys
Authors: Trevarthen C. B.
Published: October 2006

Split-brain monkeys (with forebrain divided) were trained to perform two contradictory visual tasks simultaneously, one task being presented to each eye. Usually one cerebral hemisphere dominated, but in some cases the two halves of the brain learned simultaneously. Contradictory color discriminations showed interference or transfer of learning until mid-brain commissures were also sectioned. The more extensive surgery failed to prevent transfer of simple brightness discriminations.
Goethite in Radular Teeth of Recent Marine Gastropods
Authors: Lowenstam H. A.
Published: October 2006

The x-ray diffraction patterns of the denticle material from several species show that the material consists of the mineral goethite. This is the first indication that goethite is precipitated by marine invertebrates. The mineralogy of the denticle caps has biologic and geologic implications.
Chronic Effect of Tetanus Toxin Applied Locally to the Cerebral Cortex of the Dog
Authors: Carrea Raúl , Lanari Alfredo
Published: October 2006

Tetanus toxin injected into the cortex produces convulsions, neurological disability, and a strychnine-like discharging focus, appearing after a minimal latency of 2 days and lasting more than a month. Such a focus, apparently caused by a blockade of inhibitory synapses, does not demonstrate any major damage in microscopic studies.
Architecture of the Human Lung
Authors: Weibel Ewald R. , Gomez Domingo M.
Published: October 2006

An attempt has been made to define quantitatively the architecture of airways and blood vessels of the human lung. For this purpose five normal lungs from individuals aged 8 to 74 years were subjected to a dimensional analysis by several methods of measurement based on statistical principles.

The elements of the "respiratory zone" may be regarded as randomly distributed in the lung. There are essentially the same number of alveoli (300 million), alveolar ducts (14 million), and capillary segments (280 billion) in all lungs. The dimensions of these architectural elements are shown to depend mainly on the size of the lung. The effect on these dimensions of such functional variables as the degree of inflation of the lung or of the filling of capillaries with blood are discussed.

The alveolar and alveolar-capillary surface areas, which are of importance in the analysis of gas exchange between air and blood, are found to increase with the size of the lung. In our material, both varied in the range of 40 to 80 square meters.

The elements of the conductive zone of the lung show a polar orientation. The airways have, on the average, 23 generations of dichotomous branching; the pulmonary arteries reach the precapillaries after about 28 generations. The average diameters of the airway and blood-vessel elements at each generation appear to follow the laws of "best" dimensions. The functional significance of this finding is discussed.

It is suggested that morphometric studies conducted according to this general model may be useful in the anatomical description of other organs.
Action Spectrum for Developmental Photo-Induction of the Blue-Green Alga
Nostoc muscorum
Authors: Lazaroff Norman , Schiff Jerome
Published: October 2006

The dark-grown cyanophyte requires a brief exposure to light from the 650 mμ region of the spectrum before it can complete its developmental cycle. Induction is reversed by exposure to green light. A blue protein, presumably allophycocyanin (absorption maximum, 650 mμ) has been demonstrated in aqueous extracts of the cyanophycean cells.
Isolation of the Sex Attractant of the American Cockroach
Authors: Wharton D. R. A. , Black E. D. , Merritt C. , Wharton Martha L. , Bazinet M. , Walsh J. T.
Published: October 2006

The sex attractant of the female American cockroach,
Periplaneta americana
(L.), has been collected and isolated by a combination of extraction, distillation, and chromatographic procedures. Progress through these procedures has been followed by bioassay and by ultraviolet spectrophotometry. The attractant has been isolated by gas chromatography, and characterization by mass spectrometry is proceeding.
Formation of Ion-Permeable Channels by Tumor Necrosis Factor-α
Authors: Kagan Bruce L. , Baldwin Rae Lynn , Munoz David , Wisnieski Bernadine J.
Published: October 2006

Tumor necrosis factor-α (TNF, cachectin), a protein secreted by activated macrophages, participates in inflammatory responses and in infectious and neoplastic disease states. The mechanisms by which TNF exerts cytotoxic, hormonal, and other specific effects are obscure. Structural studies of the TNF trimer have revealed a central pore-like region. Although several amino acid side chains appear to preclude an open channel, the ability of TNF to insert into lipid vesicles raised the possibility that opening might occur in a bilayer milieu. Acidification of TNF promoted conformational changes concordant with increased surface hydrophobicity and membrane insertion. Furthermore, TNF formed pH-dependent, voltage-dependent, ion-permeable channels in planar lipid bilayer membranes and increased the sodium permeability of human U937 histiocytic lymphoma cells. Thus, some of the physiological effects of TNF may be elicited through its intrinsic ion channel-forming activity.
Isolation of a Complementary DNA that Encodes the Mammalian Splicing Factor SC35
Authors: Fu Xiang-Dong , Maniatis Tom
Published: October 2006

The mammalian splicing factor SC35 is required for the first step in the splicing reaction and for spliceosome assembly. The cloning and characterization of a complementary DNA encoding this protein revealed that it is a member of a family of splicing factors that includes mammalian SF2/ASF. This family of proteins is characterized by the presence of a ribonucleoprotein (RNP)-type RNA binding motif and a carboxyl-terminal serine-arginine-rich (SR) domain. A search of the DNA sequence database revealed that the thymus-specific exon (E
T
) of the c-
myb
proto-oncogene is encoded on the antisense strand of the SC35 gene.
Fluorine Compounds of Xenon and Radon
Authors: Chernick C. L. , Claassen H. H. , Fields P. R. , Hyman H. H. , Malm J. G. , Manning W. M. , Matheson M. S. , Quarterman L. A. , Schreiner F. , Selig H. H. , Sheft I. , Siegel S. , Sloth E. N. , Stein L. , Studier M. H. , Weeks J. L. , Zirin M. H.
Published: October 2006

Xenon and fluorine combine readily. Xenon tetrafluoride is a colorless crystalline material, stable at room temperature. The existence of at least one other fluoride and two oxyfluorides has been demonstrated. The heaviest "inert gas," radon, also reacts with fluorine, yielding a compound less volatile than xenon tetrafluoride.
Experimental Morphine Addiction: Method for Automatic Intravenous Injections in Unrestrained Rats
Authors: Weeks James R.
Published: October 2006

An operant behavioral study on morphine addiction utilized a self-injection technique for giving intravenous injections to relatively unrestrained rats. The rate of self-injection varied inversely with the dose. Morphine was a reinforcer that produced almost immediate satiation.
Communication with Queen Honey Bees by Substrate Sound
Authors: Wenner Adrian M.
Published: October 2006

A caged queen honey bee, installed in an observation hive which already contained a virgin queen, piped in response to artificial piping which was played to it through the substrate. The experiments which followed this observation provide the first direct quantitative evidence that sound, at least in the range of 600 to 2000 cycles per second, is perceived by honey bees and that information is transmitted through sound from one bee to another.
Angiotensin II: Its Metabolic Fate
Authors: Khairallah P. A. , Page Irvine H. , Bumpus F. M. , Smeby R. R.
Published: October 2006

Randomly labeled tritiated angiotensin has been prepared with a specific activity of 300 μc/mg and with undiminished pressor and oxytocic activity. After infusion, angiotensin accumulated in the kidneys, adrenal glands, and uterus. Thirty minutes after infusion high levels of radioactivity appeared in brain, but the electrophoretic mobility differed from that of angiotensin II. Incubation of angiotensin with hemolyzed human red blood cells or diluted human plasma rapidly inactivated the pressor activity with production of metabolic products separable by paper chromatography. But if undiluted plasma is used with incubation up to 6 hours, no loss of activity occurs.
A Theory of Middle Ear Muscle Function at Moderate Sound Levels
Authors: Simmons F. Blair , Beatty Dana L.
Published: October 2006

The minor amplitude modulations of auditory input, which are introduced by the middle ear muscle acoustic reflex at moderate and low sound intensities in the cat, may contribute significantly to signal analysis or attention mechanisms of the auditory system.
Pre-Columbian Alloy Objects from Guerrero, Mexico
Authors: Brush Charles F.
Published: October 2006

Fifteen metal artifacts from coastal Guerrero were analyzed. Gold-, silver-, and copper-base alloys were found, and a deliberate manufacture of bronze is indicated. Metallographic studies show a high degree of sophistication in the art of cold-working metal.
Rapamycin-Induced Inhibition of the 70-Kilodalton S6 Protein Kinase
Authors: Price Daniel J. , Grove J. Russell , Calvo Victor , Avruch Joseph , Bierer Barbara E.
Published: October 2006

The immunosuppressant rapamycin inhibited proliferation of the H4IIEC hepatoma cell line. Rapamycin, but not its structural analog FK506, also inhibited the basal and insulin-stimulated activity of the p70 ribosomal protein S6 kinase. By contrast, insulin stimulation of the p85 Rsk S6 kinase and mitogen-activated protein (MAP) kinase activity were unaffected by drug. Rapamycin treatment of COS cells transfected with recombinant p70 S6 kinase completely inhibited the appearance of the hyperphosphorylated form of p70 S6 kinase concomitant with the inhibition of enzyme activity toward 40
S
subunits. Thus, rapamycin inhibits a signal transduction element that is necessary for the activation of p70 S6 kinase and mitogenesis but unnecessary for activation of p85 Rsk S6 kinase or MAP kinase.
Bonding in Xenon Fluorides and Halogen Fluorides
Authors: Pitzer Kenneth S.
Published: October 2006

The bonding in rare gas fluorides is similar to that in halogen polyfluorides, and the stability of such compounds should depend primarily on the ionization potential of the central atom. This theory is consistent with findings for all known compounds of the system and yields predictions concerning other systems.
Vascular Smooth Muscle: Dual Effect of Calcium
Authors: Bohr David F.
Published: October 2006

The first part of the contractile response of rabbit aorta to epinephrine is depressed by elevation of calcium concentration; the second is potentiated. These observations suggest that the rate-limiting factor for the former is membrane excitability (depressed by increased calcium), while that for the latter is the role that calcium plays in coupling membrane excitation with the development of tension by the contractile protein (a function that is augmented by increased calcium).
Hippocampectomy and Behavior Sequences
Authors: Kimble Daniel P. , Pribram Karl H.
Published: October 2006

Four monkeys with bilateral hippocampal lesions were trained to respond sequentially to visual stimuli, presented with an automated discrimination apparatus. Two different sequential tasks were presented. The experimental animals were significantly inferior on both problems to six control animals. Since no impairment appeared on simple visual discriminations presented with intertrial intervals from 5 seconds to 6 minutes, simple sensory deficits and "short-term" memory impairments appear unlikely. The results strengthen the interpretation that bilateral hippocampal lesions interfere with the acquisition of those behaviors which involve the execution of sequential responses.
Biosynthesis of Norepinephrine in Isolated Canine Heart
Authors: Chidsey Charles A. , Kaiser Gerard A. , Braunwald Eugene
Published: October 2006

Radioactive dopamine was injected into the blood that was perfusing an isolated heart preparation. Analysis of the norepinephrine obtained from the heart 1 hour later demonstrated that it contained radioactivity. Between 1.4 and 10.8 percent of the norepinephrine present had been formed from the dopamine. The turnover of norepinephrine was substantially higher in the ventricles than in the atria.
Deuterated Water Effects on Acid Ionization Constants
Authors: Martin R. Bruce
Published: October 2006

Linear relations of the form Δ
pK
=
pK
D
-
pK
H
=
a
+
b
pK
H
relating ionization constants of acids in light and heavy water must have the same slope
b
for any kind of acid unless the previously unconsidered charge type is important or this equation is not valid.
Ureotelism of Echidna and Platypus
Authors: Denton D. A. , Reich Magda , Hird F. J. R.
Published: October 2006

Analyses of plasma and urine and the demonstration of arginase in the liver indicate that both the adult echidna (
Tachyglossus aculeatus
) and platypus (
Ornithorhynchus
) are ureotelic.
Xenon Tetrafluoride: Fluorine-19 High-Resolution Magnetic Resonance Spectrum
Authors: Brown Thomas H. , Whipple E. B. , Verdier Peter H.
Published: October 2006

The F
19
spectrum of XeF
4
dissolved in anhydrous hydrogen fluoride has been observed at two frequencies, yielding a F
19
chemical shift of 175 parts per million to lower field than the solvent and a Xe
129
-F
19
spin-spin coupling constant, confirmed by double irradiation, of 3860 cycles per second. Absence of fast F
19
chemical exchange and collapse of the Xe
131
-F
19
coupling by quadrupole relaxation may be inferred from the spectrum.
Infant Handling: Effects on Avoidance Learning, Brain Weight, and Cholinesterase Activity
Authors: Tapp Jack T. , Markowitz Hal
Published: October 2006

Infant rats were "handled" by removing them periodically from their home cages. "Non-handled" rats were left undisturbed. Half of the animals were killed at weaning, and weights and cholinesterase activity were determined on four different sections of the brain. The remaining animals were conditioned to avoid an administered shock. Handling increased ventral-cortex and subcortical weights and decreased subcortical cholinesterase. No differences in avoidance conditioning were observed.
Polymorphism and Population Density in the African Land Snail,
Limicolaria martensiana
Authors: Owen D. F.
Published: October 2006

In natural populations of the African land snail,
Limicolaria martensiana
, the degree of polymorphism in color and pattern may vary with the density of the population. This could occur because predators eat the snails selectively and use past experience as a guide in finding further prey. Hence contrasting color forms may be at an advantage in dense populations where predators would have ample opportunity to learn to recognize prey.
Microdetermination of Calcium by Aequorin Luminescence
Authors: Shimomura Osamu , Johnson Frank H. , Saiga Yo
Published: October 2006

A bioluminescent protein, aequorin, isolated from the jellyfish
Aequorea
in dilute disodium ethylenediaminetetraacetate solution, emits light on addition specifically of Ca
++
or Sr
++
, thus providing the basis for a simple, quantitative micromethod for the determination of these cations, especially in biological fluids.
Erythrocytes: 5′-Adenylic Acid Deaminase Requirement for Ammonia or Monovalent Metal Ion
Authors: Askari Amir
Published: October 2006

5′-Adenylic acid deaminase free from sodium and potassium ion is prepared from erythrocytes by a convenient method. Like adenosine triphosphatase and adenylic kinase from erythrocytes, the deaminase is activated by some monovalent cations, but unlike these enzymes it requires the presence of a monovalent cation. In all three instances the pattern of activation by ions is similar and suggests a common mechanism.
Respiration of Heart Muscle as Affected by Oxygen Tension
Authors: Whalen William J. , Fangman John
Published: October 2006

Isolated cat papillary muscles were exposed to gas mixtures containing carbon dioxide and oxygen. In muscles exposed during the second of three periods to 25 percent oxygen, the volume of oxygen consumed (Q

O
2

) was depressed by 50 percent, but returned to the control level during a third period at 98 percent oxygen. The work capacity was not significantly altered if the partial pressure of oxygen was low.
A Picolinic Acid Derivative: A Plant Growth Regulator
Authors: Hamaker John W. , Johnston Howard , Martin Robert T. , Redemann Carl T.
Published: October 2006

4-Amino-3,5,6-trichloropicolinic acid is more toxic to many broad-leaved plants than 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid. It is comparable in absorption by foliage, in translocation, and in soil-leaching characteristics; in soil, however, it retains its activity for a longer time.
Geometry of the Perxenate Ion
Authors: Hamilton Walter C. , Ibers James A. , Mackenzie Donald R.
Published: October 2006

A three-dimensional x-ray analysis of a crystalline solid of Xe
+8
formed by the reaction of XeF
6
with sodium hydroxide solution indicates that it is sodium perxenate octahydrate, Na
4
XeO
6
⋅ 8H
2
O. The perxenate ion, XeO
6
-4
, has approximately a regular octahedral configuration with a mean xenon-oxygen bond length of 1.875 Å.
Serum Uric Acid in Young Mongoloids
Authors: Fuller Ray W. , Concon Jose M.
Published: October 2006

A highly significant increase (
P
< .005) in average uric acid level was found in the blood serum of 25 mongoloids in the age range of 2 to 12 years, with a mean age of 6 years, when levels were compared with those in nonmongoloid, mentally retarded children. These data confirm our previous results with 40 mongoloids whose mean age was 23.7 years, and indicate that elevated uric acid levels are present throughout most of the life of these subjects.
Metastable Rubidium Aluminum Silicate with a Hexagonal Sheet Structure
Authors: Sorrell Charles A. , Negas Taki
Published: October 2006

A compound of composition RbAlSi
3
O
8
, with a structure of double sheets of silica-alumina tetrahedra with common apices held together by rubidium ions in 12-fold coordination, may be crystallized from a melt by rapid cooling. The compound is an analog of the metastable forms of the calcium, barium, strontium, and lead feldspars.
Unmineralized Fossil Bacteria
Authors: Bradley W. H.
Published: October 2006

Unmineralized bacterial cells, mostly
Micrococcus
sp., but including also
Streptococcus
sp. and
Actinomyces
sp., were found in enormous numbers in lake beds of the Newark Canyon Formation of Early Cretaceous age, Eureka County, Nevada. The micrococci are black, and have an average diameter about 0.5 μ. Similar black micrococci (0.4 to 0.7 μ) were found in profusion in the bottom mud of Green Lake, New York. About 80 percent of this mud consists of minute idiomorphic calcite crystals and about 20 percent of these contain enormous numbers of the black micrococci. It is suggested that the Early Cretaceous bacterial cells owe their preservation to occlusion in calcite crystals that grew in a black, bacterial mud in a meromictic lake in which part of the Newark Canyon Formation accumulated.
Skin Impedance and Phase Angle as a Function of Frequency and Current
Authors: Plutchik Robert , Hirsch Henry R.
Published: October 2006

The impedance of the human skin decreased from approximately 130 to 30 Kohm as the frequency of a-c input increased from 1 to 1000 cycles per second. Over this same range of frequencies, the phase angles changed from -2 to -58 degrees. Changing the peak-to-peak current through the subject from 14 to 62 microamperes had no effect on either the impedance of the skin or the phase angles.
Thermally Induced Genital Appendages on Mosquitoes
Authors: Horsfall William R. , Anderson John F.
Published: October 2006

Temperatures above those normally present in larval sites of certain mosquitoes (for example,
Aedes stimulans
) cause larvae of potential males to be feminized in all degrees. Certain combinations of temperatures will affect these larvae so that an abnormal pair of genital appendages consistently appears in addition to the usual pair. These appendages appear to be masculine and are presumed to come from imaginal discs that are latent in present-day Diptera.
cis
-3-Chloroacrylic Acid: A New Cotton Defoliant and Crop Desiccant
Authors: Herrett Richard A. , Kurtz Abraham N.
Published: October 2006

cis
-3-Chloroacrylic acid is a potent cotton defoliant and a crop desiccant. Relationships between structure and activity indicate a relatively high degree of specificity, since minor modifications in structure result in loss of activity.
Interactions of Small Nuclear RNA's with Precursor Messenger RNA During in Vitro Splicing
Authors: Wassarman David A. , Steitz Joan A.
Published: October 2006

Precursor messenger RNA splicing requires multiple factors including U1, U2, U4, U5, and U6 small nuclear RNA′s. The crosslinking reagent psoralen was used to analyze the interactions of these RNA′s with an adenovirus precursor messenger RNA in HeLa nuclear extract. An endogenous U2-U4-U6 crosslinkable complex dissociated upon incubation with precursor messenger RNA. During splicing, U1, U2, U5, and U6 became crosslinked to precursor messenger RNA and U2, U5, and U6 became crosslinked to excised lariat intron. U2 also formed a doubly crosslinked complex with U6 and precursor messenger RNA. The U1, U5, and U6 crosslinks to the precursor messenger RNA mapped to intron sequences near the 5′ splice site, whereas the U2 crosslink mapped to the branch site. The kinetics of crosslink formation and disappearance delineates a temporal pathway for the action of small RNA′s in the spliceosome. Potential base pairing interactions between conserved sequences in the small nuclear RNA′s and precursor messenger RNA at the sites of crosslinking suggest that the 5′ splice site is defined in several steps prior to the first cleavage event.
The Primary Structure of MEK, a Protein Kinase that Phosphorylates the
ERK
Gene Product
Authors: Crews Craig M. , Alessandrini Alessandro , Erikson Raymond L.
Published: October 2006

Mitogen-activated protein (MAP) kinases, also known as extracellular signal-regulated kinases (ERKs), are thought to act at an integration point for multiple biochemical signals because they are activated by a wide variety of extracellular signals, rapidly phosphorylated on threonine and tyrosine, and highly conserved. A critical protein kinase lies upstream of MAP kinase and stimulates the enzymatic activity of MAP kinase. The structure of this protein kinase, denoted MEK1, for
M
AP kinase or
E
RK
k
inase, was elucidated from a complementary DNA sequence and shown to be a protein of 393 amino acids (43,500 daltons) that is related most closely in size and sequence to the product encoded by the
Schizosaccharomyces pombe
byr1
gene. The
MEK
gene was highly expressed in murine brain, and the product expressed in bacteria phosphorylated the
ERK
gene product.
Removal of Nonhomologous DNA Ends in Double-Strand Break Recombination: the Role of the Yeast Ultraviolet Repair Gene
RAD1
Authors: Fishman-Lobell Jacqueline , Haber James E.
Published: October 2006

Double-strand breaks (DSBs) in
Saccharomyces cerevisiae
can be repaired by gene conversions or by deletions resulting from single-strand annealing between direct repeats of homologous sequences. Although
rad1
mutants are resistant to x-rays and can complete DSB-mediated mating-type switching, they could not complete recombination when the ends of the break contained approximately 60 base pairs of nonhomology. Recombination was restored when the ends of the break were made homologous to donor sequences. Additionally, the absence of
RAD1
led to the frequent appearance of a previously unobserved type of recombination product. These data suggest
RAD1
is required to remove nonhomologous DNA from the 3′ ends of recombining DNA, a process analogous to the excision of photodimers during repair of ultraviolet-damaged DNA.
Invertebrate Ferritin: Occurrence in Mollusca
Authors: Towe Kenneth M. , Lowenstam H. A. , Nesson M. H.
Published: October 2006

Ferritin, in both crystalline and paracrystalline forms, occurs in the columnar epithelial cells of the dorsal wall of the radula of the marine chiton
Cryptochiton stelleri
, order, Polyplacophora. The ferritin occurs in association with the magnetite of the radular teeth. It has been isolated and crystallized in the presence of cadmium sulfate.
Paleontologic Technique for Defining Ancient Pole Positions
Authors: Stehli F. G. , Helsley C. E.
Published: October 2006

Taxonomic diversity gradients appear to offer a quantitative paleontologic technique for obtaining ancient positions of the rotational pole of the earth. Statistical analysis of a model based on the taxonomic diversity of Recent planktonic foraminifera shows a close relationship to the latitudinal temperature gradient and, thus permits location of the pole. A similar analysis for Permian orthotetaceid brachiopods suggests a pole near the present position. Available data on diversity fit a present earth model better than one based on Permian paleomagnetic results and thus suggest that it may be necesary to consider a model for the earth's magnetic field which does not require coincidence of the magnetic and rotational poles.
Separation of Transducer and Impulse-Generating Processes in Sensory Receptors
Authors: Loewenstein W. R. , Terzuolo C. A. , Washizu Y.
Published: October 2006

New evidence is presented that spike and transducer processes in sensory receptors are independent events; impulse activity in the crustacean stretch receptor neuron and the mammalian pacinian corpuscle was selectively blocked by a compound (tetrodotoxin) without affecting any of the parameters of the generator potential.
Species Abundance: Natural Regulation of Insular Variation
Authors: Hamilton Terrell H. , Rubinoff Ira , Barth Robert H. , Bush Guy L.
Published: October 2006

Variation in numbers of land plant species on islands in the Galapagos Archipelago can be predicted on the basis of elevation, area of the adjacent island, distance from the nearest island, and distance from the center of the archipelago, but not on the basis of the area of the host island. Multiple linear regression (y = bx
1
+ bx
2
. . .) gives better "goodness of fit" than curvilinear analysis (y = bx
z
). The variation in number of species on large islands can be predicted more accurately than the variation on small ones. Ecologic diversity and isolation are the natural regulators of species abundance.
Additive Inheritance of Serum Cholesterol Level in Mice
Authors: Bruell Jan H.
Published: October 2006

Serum cholesterol level (SCL) was measured in 600 mice belonging to five inbred strains of mice (DBA/1J, C57BL/10J, A/J, C3H/HeJ, and BALB/cJ) and all 20 F
1
hybrids resulting from the systematic crossing of the inbreds. Diet was kept constant and its effect on SCL was not evaluated. The data show that in mice, the mode of inheritance of SCL is neither dominant nor recessive, but is intermediate. A simple additive model accounts for the results: the SCL is a linear function of the SCL of the mother, the SCL of the sire, and the sex of the subject; the three factors do not interact.
Erythropoietin Production Following Gamma Irradiation and Hemorrhage in Dogs
Authors: Pesic N. , Radotic M. , Hajdukovic S.
Published: October 2006

The production of erythropoietin in dogs increased after they had been exposed to 300 rad of gamma rays and then subjected to hemorrhage.
Ethacrynic Acid: Diuretic Property Coupled to Reaction with Sulfhydryl Groups of Renal Cells
Authors: Komorn Robert M. , Cafruny Edward J.
Published: October 2006

Ethacrynic acid, injected intravenously after surgical removal of one kidney of anesthetized dogs, lowered the concentration of protein-bound sulfhydryl groups in cells of the remaining kidney. Chloride excretion and urinary output of the kidney exposed to the drug increased. These findings indicate that the diuresis produced by ethacrynic acid may be related to its capacity for binding sulfhydryl groups of renal cellular proteins.
Cytochrome Content of Mitochondria Stripped of Inner Membrane Structure
Authors: Chance B. , Parsons D. F. , Williams G. R.
Published: October 2006

The cytochrome composition of mitochondrial fractions which have been stripped of inner membrane subunits by exposure to high-frequency sound have been examined by low-temperature spectroscopy. The ratio of cytochrome c to cytochrome a is not changed by the treatment, but the concentration of cytochrome per milligram of protein is increased and the concentrations of cytochromes
c
1
and
b
change slightly. These cytochromes (
c
1
and
b
) may be at least partly located in the subunits of the inner membrane, but the idea that all the respiratory components are located in single subunits of the mitochondrial cristae may be considered to be disproved.
Diploid and Endoreduplicated Cells: Measurements of DNA
Authors: Bell Alex G.
Published: October 2006

Two-wavelength microspectrophotometry has shown that endoreduplicated cells in an x-irradiated culture of human leukocytes contained about twice as much DNA as diploid cells from the same culture. This supports the assumption that endoreduplicated cells represent a form of polyploidy.
Fission-Track Ages and Track-Annealing Behavior of Some Micas
Authors: Fleischer R. L. , Price P. B. , Symes E. M. , Miller D. S.
Published: October 2006

The density of tracks from spontaneously fissioning uranium atoms in mica has been used to make quantitative measurements of geologic ages. In comparison with methods in which ages are derived from measurements of radioactive decay products, the fission track method is much simpler and is usually accurate for micas up to a few hundred million years old. Annealing experiments suggest that high ambient temperatures are responsible for track fading in the older samples.
Marine Sediments: Effects of a Tube-Building Polychaete
Authors: Fager E. W.
Published: October 2006

The marine tube-building polychaete,
Owenia fusiformis
, selects sand grains of tablet form for its tube. It can concentrate the mineral hornblende at least 25-fold and these concentrations may persist after the death of the worm.
Owenia
and a small anemone,
Zaolutus actius
, can act together to stabilize the sand surface against movement by wave surge. The result is the formation of an area of stabilized substrate, with which characteristic animals and plants are associated, in the midst of a region of shifting granular substrate.
Allelic Mapping in Yeast by X-ray-Induced Mitotic Reversion
Authors: Manney T. R. , Mortimer R. K.
Published: October 2006

A new method for determining the sequence of mutational sites is based on the linear dose-effect relation for x-ray induction of allelic recombination in
Saccharomyces cerevisiae
. Mutations at two loci have been mapped by this method. The use of x-ray simplifies allelic mapping and greatly increases its sensitivity.
Bile Duct Restoration in
Rana pipiens
after Ligation of the Hepatoduodenal Ligament
Authors: Streett J. C.
Published: October 2006

A single cotton ligature closed the common bile duct, the hepatic artery, and the hepatic portal vein. The continuity of the bile duct was restored in 14 of 69 cases, the restoration process being associated with mitosis in the bile duct epithelium. There was evidence that the continuity of the blood vessels was also restored.
Helium Difluoride: Possible Preparative Techniques Based on Nuclear Transmutations
Authors: Pimentel George C. , Spratley Richard D. , Miller Alan R.
Published: October 2006

It might be possible to prepare difluoride by beta decay of tritium, lithium-6 transmutation, or alpha-particle bombardment. In the first method, which may be the most feasible, tritiated potassium bifluoride could be used as a host lattice. The beta-decay recoil energy would not dislodge the daughter helium atom from the host site, thus helium difluoride could perhaps be formed in an ideally shaped lattice site.
Histone Staining with Ammoniacal Silver
Authors: Black Maurice M. , Ansley H. R.
Published: October 2006

Under controlled conditions, ammoniacal silver (A-S) stains the bands of Dipteran salivary gland chromosomes in a precise and selective manner. Such staining is dependent upon the histone content of the band, as shown by the effects of selective extraction and blocking of the histones. The effects of acid extraction and HONO solution on the A-S staining of different bands suggest that specific genes may have particular histones associated with them.
Intracranial Reward Delay and the Acquisition Rate of a Brightness Discrimination
Authors: Keesey Richard E.
Published: October 2006

An application of the techniques of intracranial self-stimulation to the study of delayed reward indicates that the rate of discrimination learning for stimulation of the hypothalamus is a decreasing function of the delay interval. The resulting delay-of-reward gradient does not appear to differ appreciably from other such gradients based on food reward.
Sulfate Particulates: Size Distribution in Pittsburgh Air
Authors: Corn Morton , DeMaio Lawrence
Published: October 2006

Sulfate particles with diameters of less than 1.7 microns contribute approximately 40 percent by weight to total sulfate particulate in Pittsburgh air. The irritant nature of these particles and their small size and associated long atmospheric residence time, as well as the short half-life of sulfur dioxide in the atmosphere, suggest that particulate sulfate may be a better indicator of atmospheric pollution than sulfur dioxide.
Actinomycin D: Effect on the Immune Response
Authors: Wust Carl J. , Gall Clara L. , Novelli G. David
Published: October 2006

Actinomycin D injected simultaneously with sheep erythrocytes in female rats caused a delay in the immune response but had no effect on the rate or maximum amount of hemagglutinin produced. The delay was roughly proportional to the concentration of the antibiotic administered, and was up to 2 days for 75 μg in a 200-gram female rat (sublethal dose for females). The dose effect in the delay in response is consistent with the time when actinomycin would no longer be available to bind with newly synthesized DNA and when messenger-RNA production could occur. Similar results were obtained with another antigen, the enzyme β-galactosidase, in male rats during the secondary response.
Visual Problem-Solving in a Bottlenose Dolphin
Authors: Kellogg Winthrop N. , Rice Charles E.
Published: October 2006

A captive 8-year-old dolphin, well adapted to contact with human beings, was tested by the discrimination method for underwater perception of visual forms or patterns. The animal successfully discriminated 21 of the 25 pairs of stimuli presented. After having learned a particular combination, the dolphin was immediately able to respond to different but related pairs which had been modified in various ways. The memory of the animal for discriminations previously made was excellent.
Explosive Welding with Nitroguanidine
Authors: Sadwin Lippe D.
Published: October 2006

By using the explosive nitroguanidine, continuous welds can be made between similar and dissimilar metals. Since low detonation pressures are attainable, pressure transfer media are not required between the explosive and the metal surface. The need for either a space or an angle between the metals is eliminated, and very low atmospheric pressures are not required. Successful welds have been made between tantalum and 4140 steel, 3003H14 aluminum and 4140 steel, and 304 stainless steel and 3003H14 aluminum.
Dissociation and Recovery of a Response Learned under the Influence of Chlorpromazine or Saline
Authors: Otis Leon S.
Published: October 2006

Rats trained in an avoidance response while under the influence of chlorpromazine and then tested after receiving an injection of saline, or trained after receiving injections of saline and tested after an injection of chlorpromazine, showed greater dissociation and less recovery of the avoidance response than animals that received only injections of saline, or only injections of chlorpromazine during both training and testing sessions.
Sensitivity of Female Inbreds of
Cucumis sativus
to Sex Reversion by Gibberellin
Authors: Shifriss Oved , George W. L.
Published: October 2006

Two female inbred cucumbers were developed by substituting gene
Acr
for acr in the genetic backgrounds of the monoecious races Marketer and Tokyo, which exhibit weak and strong male tendency respectively. Marketer females are resistant and Tokyo females are sensitive to sex reversion in response to treatments with gibberellin A
3
. Resistance and sensitivity of this type appear to depend upon the genetic system which controls sex tendency.
A Comprehensive Genetic Linkage Map of the Human Genome
Authors:   NIH/CEPH Collaborative Mapping Group
Published: October 2006

A genetic linkage map of the human genome was constructed that consists of 1416 loci, including 279 genes and expressed sequences. The loci are represented by 1676 polymorphic systems genotyped with the CEPH reference pedigree resource. A total of 339 microsatellite repeat markers assayed by PCR are contained within the map, and of the 351 markers with heterozygosities of at least 70%, 205 are microsatellites. Seven telomere loci define physical and genetic endpoints for 2q, 4p, 7q, 8p, 14q, 16p, and 16q, and in other cases distal markers on the maps have been localized to terminal cytogenetic bands. Therefore, at least 92% of the autosomal length of the genome and 95% of the X chromosome is estimated to be spanned by the map. Since the maps have relatively high marker density and numerous highly informative loci, they can be used to map disease phenotypes, even for those with limited pedigree resources. The baseline map provides a foundation for achieving continuity of clone-based physical maps and for the development of a truly integrated physical, genetic, and cytogenetic map of the human.
Bacteriophage λ
PaPa
: Not the Mother of All λ Phages
Authors: Hendrix Roger W. , Duda Robert L.
Published: October 2006

The common laboratory strain of bacteriophage λ—λ wild type or λ
PaPa
—carries a frameshift mutation relative to Ur-λ, the original isolate. The Ur-λ virions have thin, jointed tail fibers that are absent from λ wild type. Two novel proteins of Ur-λ constitute the fibers: the product of
stf
, the gene that is disrupted in λ wild type by the frameshift mutation, and the product of gene
tfa
, a protein that is implicated in facilitating tail fiber assembly. Relative to λ wild type, Ur-λ has expanded receptor specificity and adsorbs to
Escherichia coli
cells more rapidly.
Cellular Mechanisms in Experimental Epileptic Seizures
Authors: Matsumoto H. , Marsan C. Ajmone
Published: October 2006

Action potentials of single cells, recorded by means of extracellular microelectrodes from the cat's cerebral cortex after topical application of penicillin, undergo characteristic changes in the course of seizure episodes. In individual neurons, these changes in spike configuration are fully reversible and are repeatedly observed with each of such episodes. Two alternative interpretations offered for these findings appear to be critically dependent upon the relationship between the position of the microelectrode and the cell itself: there might be a transitory failure of the spike to invade part of the neuronal membrane or transitory neuronal swelling.
Estrone Inhibition of Cholesterol Biosynthesis at the Mevalonic Acid Stage
Authors: Merola A. J. , Arnold A.
Published: October 2006

Studies on the synthesis of cholesterol with cell-free homogenates of liver from rats treated with graded doses of estrone show that, at doses of estrone which cause a reduction in blood cholesterol, there is an accompanying inhibition of cholesterol biosynthesis. Furthermore, this inhibition appears to occur at the stage of cholesterol biosynthesis at which mevalonate is decarboxylated.
Audiogenic Seizures, the Dilute Locus, and Phenylalanine Hydroxylase in DBA/1 Mice
Authors: Huff Sally D. , Fuller John L.
Published: October 2006

Reduced audiogenic seizure susceptibility in dilute mice was associated with enhancement of phenylalanine hydroxylase activity, previously reported as low in dilute mice. Though nutritional changes complicate the interpretation, evidence exists for a mutation linked with dilute which modifies susceptibility.
Endogenous Metabolic Factor in Schizophrenic Behavior
Authors: Berlet H. H. , Bull C. , Himwich H. E. , Kohl H. , Matsumoto K. , Pscheidt G. R. , Spaide J. , Tourlentes T. T. , Valverde J. M.
Published: October 2006

Exacerbations of schizophrenic behavior are associated with elevations of urinary tryptophan metabolites. Free tryptophan and methionine possibly arising from the breakdown of muscle protein may act like an endogenous metabolic factor which enhances behavioral worsening. Some of the apparently spontaneous activations of psychotic symptoms may be intensified by the endogenous liberation of these two compounds.
Bilirubin: Acute Effects in Newborn Rhesus Monkeys
Authors: Behrman Richard E. , Hibbard Emerson
Published: October 2006

Sustained concentrations of serum bilirubin of over 30 mg/ 100 ml were associated with decreased concentrations of molecular oxygen, measured polarographically in the peritoneum of infant monkeys. This effect may precede the intracellular action of bilirubin and contribute to the greater severity of experimental manifestations of hyperbilirubinemia with antecedent asphyxia than of asphyxia alone.
Mechanisms of Receptor Adaptation
Authors: Mendelson Martin , Loewenstein Werner R.
Published: October 2006

Two determinants of adaptation in a mechanoreceptor (Pacinian corpuscle) are described. Both are filters of non-transients. One, a mechanical filter, prevents static components of the mechanical stimulus from reaching the transducer element (nerve ending). This filter is represented by the laminar capsule of the receptor. When the capsule is eliminated by dissection, the generator potential of the nerve ending in response to a sustained stimulus is markedly prolonged. Another filter is represented by an inactivation process of the mechanisms of nerve impulse initiation which prevents a steady outward current from producing repetitive impulses. Both filters cut the duration of the receptor response to a few milliseconds.
Carbon Monoxide Production by a Bathypelagic Siphonophore
Authors: Pickwell George V. , Barham Eric G. , Wilton John W.
Published: October 2006

A physonectid siphonophore,
Nanomia bijuga
, associated with a vertically migrating deep scattering layer, has been observed with a gas-filled float at depths in excess of 300 meters in the sea. This implies that gas is secreted and maintained in the pneumatophore against a diffusion gradient of 30 atmospheres or more. Analysis of the enclosed gases revealed concentrations of carbon monoxide exceeding 90 percent. Necessary voiding of this gas during a vertical ascent of 300 meters could give rise to a transient population of bubbles which would act as sound-reflecting targets.
Cardiovascular Concomitants of the Conditioned Emotional Response in the Monkey
Authors: Stebbins William C. , Smith Orville A.
Published: October 2006

Flow transducers were surgically implanted on the terminal aorta of five monkeys. A classical conditioning procedure, in which a light preceded a brief shock, was superimposed upon a variable-interval schedule of food reinforcement for key pressing (three monkeys) and alternated with an avoidance schedule of shock reinforcement for key pressing (two monkeys). Suppression of the rate of the response of key pressing and sizable increase in blood flow and heart rate during the light were obtained for all animals.