bluuebunny/crossref_metadata_2025 huggingface dataset:
Colicin-Tolerant Mutants of
Escherichia coli
: Resistance of Membranes to Colicin E1
Authors: Bhattacharyya Pinakilal , Wendt Louis , Whitney Eleanor , Silver Simon
Published: October 2006

Colicin E1 blocks proline accumulation by membrane vesicles prepared from wild-type sensitive
Escherichia coli
. Two classes of mutant cells are unaffected by colicin. Vesicles from colicin-resistant strains are sensitive to colicin E1, whereas vesicles from colicin-tolerant strains are unaffected by colicin E1. These results suggest that the colicin E1 receptor is on the cell membrane and that colicin-tolerant strains have altered membranes while colicin-resistant strains have altered cell walls.
Fossil Membranes and Cell Wall Fragments from a 7000-Year-Old Black Sea Sediment
Authors: Degens Egon T. , Watson Stanley W. , Remsen Charles C.
Published: October 2006

Lamellar and tubular membranes and organic fragments resembling bacterial cell walls were abundant in Black Sea sediments deposited between 3000 and 7000 years ago. This time period was marked by a gradual transition from a freshwater to a seawater environment. The resulting salinity gradient in the interstitial solutions probably promoted natural chromatography and dissolution, redeposition, and preservation of organic molecules. The preservation of organic structures may have resulted from the lack of dissolved oxygen, high concentrations of metal ions, and structural reorganization during compaction.
Experimental Allergic Encephalomyelitis: Synthesis of Disease-Inducing Site of the Basic Protein
Authors: Eylar E. H. , Caccam Juanita , Jackson J. J. , Westall Fred C. , Robinson Arthur B.
Published: October 2006

A highly encephalitogenic peptide whose structure resembles the sequence of amino acids surrounding the single tryptophan residue in the encephalitogenic A1 protein from bovine myelin was synthesized. This peptide is similar in the sequence to peptic peptide E and tryptic T27, derived directly from the A1 protein, and is as active on a molar basis as the A1 protein. The major disease-inducing site of the A1 protein resides in a linear sequence of nine amino acids: H-Phe-Ser-Trp-Gly-Ala-Glu-Gly-Gln-Lys-OH. This region of the A1 protein is apparently the major encephalitogenic determinant since specific modification of the tryptophan residue in the A1 protein with 2-hydroxy-5-nitrobenzyl bromide destroyed its encephalitogenic activity.
Extinction in Goldfish: Facilitation by Intracranial Injection of RNA from Brains of Extinguished Donors
Authors: Braud Willim G.
Published: October 2006

Extracts rich in RNA were prepared from the brains of goldfish that had acquired and then extinguished a light-signaled avoidance to shock in an aquatic shuttle-box. Recipient fish injected intracranially with such extracts extinguished the response significantly faster than those injected with extracts prepared from brains of naive donors.
Quartz: Preferred Orientation in Rocks Produced by Dauphiné Twinning
Authors: Tullis Jan
Published: October 2006

X-ray analyses of quartz aggregates deformed in the laboratory and in nature show a striking difference in the preferred orientation of the positive and negative trigonal forms. These observations may be accounted for by mechanically induced Dauphiné twinning. This orienting mechanism is unusual in that it requires no permanent strain.
Thyrotropin Secretion in Rats after Hypothalamic Electrical Stimulation or Injection of Synthetic TSH-Releasing Factor
Authors: Martin Joseph B. , Reichlin Seymour
Published: October 2006

Plasma thyroid-stimulating hormone (TSH) levels, as measured by radioimmunoassay, begin to rise within 5 minutes after initiation of electrical stimulation of the medial-basal hypothalamus, become significantly elevated at 10 minutes, and reach a peak at 10 to 25 minutes. Intravenous administration of synthetic thyrotropin-releasing factor induces a marked rise in plasma thyroidstimulating hormone which is maximal within 5 minutes after administration. These data are interpreted to indicate that there are neuronal structures within the medial-basal hypothalamus which release preformed thyrotropin-releasing factor. The claim (based on bioassay data) that pyroglutamyl-histidyl-proline amide is a potent thyrotropin-releasing factor has also been confirmed by using a highly specific immunoassay system.
Asteroid Vesta: Spectral Reflectivity and Compositional Implications
Authors: McCord Thomas B. , Adams John B. , Johnson Torrence V.
Published: October 2006

The spectral reflectivity (0.30 to 1.10 microns) of several asteroids has been measured for the first time. The reflection spectrum for Vesta contains a strong absorption band centered near 0.9 micron and a weaker absorption feature between 0.5 and 0.6 micron. The reflectivity decreases strongly in the ultraviolet. The reflection spectrum for the asteroid Pallas and probably for Ceres does not contain the 0.9-micron band. Vesta shows the strongest and best-defined absorption bands yet seen in the reflection spectrum for the solid surface of an object in the solar system. The strong 0.9-micron band arises from electronic absorptions in ferrous iron on the
M2
site of a magnesian pyroxene. Comparison with laboratory measurements on meteorites and Apollo 11 samples indicates that the surface of Vesta has a composition very similar to that of certain basaltic achondrites.
Reproductive System of
Hutchinsoniella macracantha
Authors: Hessler Anita Y. , Hessler Robert R. , Sanders Howard L.
Published: October 2006

The cephalocarid crustacean
Hutchinsoniella macracantha
is a hermaphroditic species. Ova and sperm develop simultaneously. Ovaries and testes are separate, but the oviducts and vasa deferentia join and exit through a pair of common genital ducts.
Partial Reversion in Yeast: Genetic Evidence for a New Type of Bifunctional Protein
Authors: Dorfman Ben-Zion , Goldfinger Barbara Ann , Berger Marc , Goldstein Solomon
Published: October 2006

Two kinds of phenotypic expression in purine biosynthesis result from recessive mutation to
ade12
in baker's yeast. The mutants are adenine-specific, blocked in the conversion of inosine 5′-phosphate to adenylosuccinic acid; their response to inhibition of pathway activity by adenine is considerably reduced. Allelic partial reversions can restore prototrophy without correcting the regulatory defect imparted by the primary mutation. The separation of the two properties of the locus by allelic mutation supports the hypothesis that the locus specifies a protein of two independent functions, enzymatic and regulatory.
Homing Behavior, Orientation, and Home Range of Salamanders Tagged with Tantalum-182
Authors: Madison D. M. , Shoop C. Robert
Published: October 2006

Using radioactive tags, we recorded movements of salamanders (
Plethodon jordani
) in their home areas and during homing. Males occupied home areas about three times larger than those of females and made occasional excursions into outlying regions. Homing after 22- to 60-meter displacements was direct and rapid, once initiated. Course headings at 1 meter from release were random; those at 2 meters and more were home-oriented. Males initiated homing movements sooner than females, although both sexes traveled at similar rates. Increased incidence of climbing on vegetation after displacement suggests olfactory mechanisms of orientation. These observations give direct evidence of homing orientation in caudate amphibians.
Trisporic Acid Synthesis in
Blakeslea trispora
Authors: Sutter Richard P.
Published: October 2006

Cultures of the (-) strain of
Blakeslea trispora
synthesize trisporic acid C, a sex hormone, from precursors made by cultures of the (+) strain. The precursors are nonacidic compounds isolated from the culture medium of the (+) strain by chloroform extraction. Actidione does not inhibit trisporic acid synthesis from isolated precursors, suggesting that the enzymes involved in the synthesis in cultures of the (-) strain are constitutive.
Tones and Numbers: Specificity of Interference in Immediate Memory
Authors: Deutsch Diana
Published: October 2006

Recognition of the pitch of a tone was severely disrupted by the incorporation of six other tones during a 5-second retention interval, even though the intervening tones could be ignored. However, the requirement to recall six numbers spoken at equal loudness during the identical retention interval produced only a minimum decrement in the same pitch-recognition task. Further, the requirement to remember the tone produced no decrement in recall of the numbers. It is concluded that immediate memory for pitch is subject to a large interference effect which is highly specific in nature and which is not due to some limitation in general short-term memory capacity or to a distraction of attention.
Recombinant Toxins for Cancer Treatment
Authors: Pastan Ira , FitzGerald David
Published: October 2006

Recombinant toxins target cell surface receptors and antigens on tumor cells. They kill by mechanisms different from conventional chemotherapy, so that cross resistance to conventional chemotherapeutic agents should not be a problem. Furthermore, they are not mutagens and should not induce secondary malignancies or accelerate progression of benign malignancies. They can be mass-produced cheaply in bacteria as homogeneous proteins. Either growth factor-toxin fusions or antibody-toxin fusions can be chosen, depending on the cellular target.
Vision Information Center: A User-Oriented Data Base
Authors: Eichhorn Mary M. , Reinecke Robert D.
Published: October 2006

In response to the information needs of scientists and physicians who work in the field of vision, we have developed a direct-access, on-line specialized information retrieval system which combines computer-assisted instruction and bibliographic retrieval. An essential feature of the system is its accessibility via remote computer terminal. The key to the data base is a thesaurus which contains specific terminology arranged in a hierarchical structure. The thesaurus is used both for indexing the literature and for retrieving the information stored in the computer. Courses of instruction on selected subjects in ophthalmology have been programmed and form part of the data base. A search of the literature retrieval system by single subject, or by a combination of several subjects chosen from the thesaurus, retrieves the appropriate bibliographic citations. The response to the service offered by the Vision Information Center indicates that the center should expand its facilities to satisfy the needs of its clients.
Droplet Countercurrent Chromatography
Authors: Tanimura Takenori , Pisano John J. , Ito Yoichiro , Bowman Robert L.
Published: October 2006

A new form of countercurrent chromatography, named droplet countercurrent chromatography, has been developed. This all-liquid separation technique is based on the partitioning of solute between a steady stream of droplets of moving phase and a column of surrounding stationary liquid phase. Milligram quantities of dinitrophenyl (DNP) amino acids were separated with an efficiency comparable to that of gas chromatography.
Sex Pheromones: Abolition of Specificity in Hybrid Bark Beetles
Authors: Lanier G. N.
Published: October 2006

Specificity of sex pheromones maintains breeding isolation among three closely related species of spruce-infesting
Ips
. Hybrids produced in the laboratory were intermediate to the parent species in both attractiveness and response. Pheromones and pheromone receptor types in the hybrids are probably mixtures of those of the parent species.
Cardiac Glycosides and Distastefulness: Some Observations on the Palatability Spectrum of Butterflies
Authors: Duffey S. S.
Published: October 2006

The monarch butterflyDanaus plexippussequesters cardiac gylcosides from northern species ofAsclepiasformerly reported to lack these noxious compounds. Thus, a new explanation must be sought as to why the monarchs reared on these northern asclepiads are palatable to avian predators.
Fetal Movement: Development and Time Course
Authors: Edwards Diane DeA. , Edwards Joseph S.
Published: October 2006

Prenatal behavior develops in three phases: early rates, acceleration and maintenance, and deceleration to birth. Fetal activity occurs as discrete movements, bursts of activity, and prolonged activity. Four-hour samples were most representative of the daily rates of movement.
Cognitive Model of Problem-Solving in Chess
Authors: Scurrah Martin J. , Wagner Daniel A.
Published: October 2006

By performing a series of five experiments with two subjects, several aspects of one of the subject's behavior in solving chess problems were found to be predictable, and a model was developed to explain this predictability. The heuristics used in this model may be applicable in developing future computer programs for chess play.
Marine Fossils at Rancho La Brea
Authors: Valentine James W. , Lipps Jere H.
Published: October 2006

Marine assemblages of foraminifera, ostracods, mollusks, and echinoids were recovered from deposits stratigraphically beneath the classic vertebrate assemblages from the tar pits at Rancho La Brea. The marine fossils indicate deposition in quiet, shallow water and suggest that accumulation of the type Rancholabrean material began during Wisconsin time.
Cyclic Adenosine Monophosphate in Bacteria
Authors: Pastan Ira , Perlman Robert
Published: October 2006

Both cyclic AMP and a specific inducer acting in concert are required for the synthesis of many inducible enzymes in
E. coli.
Little enzyme is made in the absence of either. In contrast to the specific inducers which stimulate the synthesis only of the proteins required for their metabolism, cyclic AMP controls the synthesis of many proteins. Glucose and certain other carbohydrates decrease the differential rate of synthesis of inducible enzymes by lowering cyclic AMP concentrations. In the
lac
operon, cyclic AMP acts at the promoter site to facilitate initiation of transcription. This action requires another protein, the cyclic AMP receptor protein. The nucleotide stimulates tryptophanase synthesis at a translational level. The action of cyclic AMP in
E. coli
may serve as a model to understand its action on transcriptional and translational processes in eukaryotes.
Prolactin Localization in the Primate Pituitary by Immunofluorescence
Authors: Herbert D. C. , Hayashida T.
Published: October 2006

Cells which contain prolactin were clearly distinguished from those which contain growth hormone in adult monkey pituitary glands by means of histologic and fluorescent antibody techniques. The results indicate that in primates, as well as in other mammals, prolactin is immunochemically distinguishable from growth hormone.
l
- Δ
9
-
trans
-Tetrahydrocannabinol in Pigeons: Tolerance to the Behavioral Effects
Authors: McMillan D. E. , Harris Louis S. , Frankenheim J. M. , Kennedy James S.
Published: October 2006

Δ
9
-Tetrahydrocannabinol was injected daily, in increasing doses, in pigeons under a multiple schedule of food presentation. Within a week, a dose that initially abolished responding completely was without effect. This dose was gradually increased to 20 times its original value without disrupting the behavior. No withdrawal syndrome was detected when the cannabinol was discontinued.
Gadolinium: Distribution between Aqueous and Silicate Phases
Authors: Cullers Robert L. , Medaris L. Gordon , Haskin Larry A.
Published: October 2006

Studies of the partition of trivalent gadolinium between aqueous and silicate phases have been made at temperatures from 800° to 900°C and at pressures from 500 to 1000 bars. Constant values for the distribution coefficients for forsterite, enstatite, and diopside were obtained over a concentration range from 0.6 part per billion to 4 parts per thousand in the solid phases. Ratios of silicate crystal-aqueous phase distribution coefficients to silicate melt-aqueous phase distribution coefficients are close to the values for silicate crystal-silicate melt distribution coefficients estimated from natural systems. The free ion activity of trivalent gadolinium in the silicate melts appears to be less than one-hundredth of its value for aqueous phases of the same concentration.
Cell Surface Coatings and Membrane Potentials of Malignant and Nonmalignant Cells
Authors: Hause Lawrence L. , Pattillo Roland A. , Sances Anthony , Mattingly Richard F.
Published: October 2006

A positive surface potential indicating a cell coating is common to malignant cells, lymphocytes, and normal and malignant trophoblastic cells. This characteristic was not generally found for other normal cell types tested by microelectrode penetration.
Junctional Membrane Permeability: Restoration by Repolarizing Current
Authors: Rose Birgit
Published: October 2006

In cells of the (
Chironomus
salivary gland, junctional membrane conductance, depressed by various chemical treatments, is restored to its normal high level by currents passed inward through nonjunctional cell membrane.
A Possible Bedrock Source for Obsidian Found in Archeological Sites in Northwestern Alaska
Authors: Patton William W. , Miller Thomas P.
Published: October 2006

Recently discovered deposits of obsidian in the Koyukuk valley may be the long-sought-for source of obsidian found in archeological sites in northwestern Alaska. Obsidian from these deposits compares favorably in physical characteristics and sodium-manganese ratio with the archeological obsidian, and there is evidence that the deposits have been "mined" in the past.
A Behavioral Measure of Homosynaptic and Heterosynaptic Temporal Summation in the Self-Stimulation System of Rats
Authors: Ungerleider Leslie G. , Coons Edgar E.
Published: October 2006

Bilateral stimulation of the medial forebrain bundle with pulses of varying interpulse intervals elicited a pattern of self-stimulation behavior in the rat indicative of temporal synaptic summation: the shorter the interval the greater the response. In contrast, the effectiveness of unilateral stimulation at very short intervals was limited by neuronal refractory periods. The results support the notion that there is convergence of the medial forebrain bundle self-stimulation system from the two sides of the brain and suggest ways of studying the degree of convergence. They also suggest a technique for behaviorally comparing heterosynaptic and homosynaptic mechanisms of summation.
A Radar Snapshot of Venus
Authors: Goldstein R. M. , Rumsey H.
Published: October 2006

A radar brightness map of Venus has been obtained. It reveals interesting surface features and much structure over a large area.
Catalytic Activities of Thermally Prepared Poly-α-Amino Acids: Effect of Aging
Authors: Rohlfing Duane L.
Published: October 2006

Thermally prepared poly-α-amino acids were tested after being stored in the dry state for 5 to 10 years. Polymers effective in catalyzing the hydrolysis of
p
-nitrophenyl acetate showed the same levels of activity as observed 10 years earlier. Polymers effective in catalyzing the decarboxylation of oxaloacetic acid had in 5 years become insoluble in assay medium; their activity, however, had increased by 32 to 145 percent. The results suggest that particular primitive enzyme molecules could have been stable enough to have contributed to evolutionary processes long after they had been produced.
Polypeptide with Broad Biological Activity: Isolation from Small Intestine
Authors: Said Sami I. , Mutt Viktor
Published: October 2006

A polypeptide, which has potent and diverse biological action—including systemic vasodilation, hypotension, increased cardiac output, respiratory stimulation, and hyperglycemia—was isolated from the small intestine of the hog. The peptide has 28 amino acid residues and is chemically distinct from the kinins, "substance P," glucagon, and secretin.
Retrograde Amnesia: Production of Skeletal but Not Cardiac Response Gradient by Electroconvulsive Shock
Authors: Hine Bromfield , Paolino Ronald M.
Published: October 2006

Rats given a single electroconvulsive shock immediately after but not 60 seconds after an aversive conditioning trial exhibited behavioral retention deficits 24 hours later in a one-trial passive avoidance task. In contrast to these differential performance deficits, similar heart-rate changes, indicative of fear retention, were seen in punished animals irrespective of the time of delivery of the shock. These data suggest retention of a generalized fear to the training experience that was not revealed by the behavioral measure. The potential usefulness of concomitant behavioral and physiological response assessment in consolidation research is discussed.
Cold Resistance and Injury in Woody Plants
Authors: Weiser C. J.
Published: October 2006

It is interesting that plants can eventually acclimate fully in response to low temperatures in the absence of inductive photoperiods. This suggests that there is more than one route to resistance or more than one ignition key to start the machinery. In either case, the ability of plants to acclimate in response to more than one environmental stimulus provides adaptive flexibility which enhances survival potential.
Teratogenicity of Vitamin B
6
Deficiency: Omphalocele, Skeletal and Neural Defects, and Splenic Hypoplasia
Authors: Davis Starkey D. , Nelson Thomas , Shepard Thomas H.
Published: October 2006

Vitamin B
6
deficiency was induced in pregnant rats with a deficient diet and with 4-deoxypyridoxine, a B
6
antagonist. Treated animals developed typical skin changes of B
6
deficiency. Fetuses were small and appeared anemic. Major fetal malformations were omphalocele, exencephaly, cleft palate, micrognathia, digital defects, and splenic hypoplasia. This teratologic system was developed as a model for human syndromes that exhibit combined immunologic and neurologic or skeletal defects.
Synaptic Potentials Recorded in Cell Cultures of Nerve and Muscle
Authors: Fischbach Gerald D.
Published: October 2006

Initially dissociated spinal cord and muscle cells derived from chick embryos differentiate sufficiently in tissue culture to form functional synaptic contacts. Spontaneous and evoked potentials recorded with intracellular microelectrodes resemble synaptic responses of adult spinal cord and neuromuscular junctions.
Lack of Coincidence between Neural and Behavioral Manifestations of Cortical Spreading Depression
Authors: Carew Thomas J. , Crow Terry J. , Petrinovich Lewis F.
Published: October 2006

The presence of cortical spreading depression is typically inferred from the presence of hypesthesia. The electrocorticogram and slow-potential change were recorded during cortical spreading depression and it was found that hypesthesia remained long after the cortex recovered from neural depression. Hypesthesia, therefore, is an unreliable indicant of cortical spreading depression; if cortical spreading depression is used as a research tool, neural activity must be monitored. These data offer a special problem for memory transfer studies.
Tolerance in Transgenic Mice Expressing Major Histocompatibility Molecules Extrathymically on Pancreatic Cells
Authors: Burkly Linda C. , Lo David , Flavell Richard A.
Published: October 2006

Transgenic mice with defined expression of major histocompatibility complex (MHC) proteins provide novel systems for understanding the fundamental question of T cell tolerance to nonlymphoid self components. The MHC class II I-E and I-A and class I H-2K molecules expressed specifically on pancreatic islet or acinar cells serve as model self antigens. In these systems, transgenic proteins are not detected in the thymus or other lymphoid tissues. Yet mice are tolerant to the pancreatic MHC products in vivo; this tolerance is not induced by clonal deletion. These studies have been aided by monoclonal antibodies specific for I-E-reactive T cells and indicate that clonal anergy may be an important mechanism of tolerance to peripheral proteins.
Binding of Transforming Protein, P47

gag-crk

, to a Broad Range of Phosphotyrosine-containing Proteins
Authors: Matsuda Michiyuki , Mayer Bruce J. , Fukui Yasuhisa , Hanafusa Hidesaburo
Published: October 2006

Although the oncogene product of CT10 virus, P47

gag-crk

, does not itself phosphorylate proteins at tyrosine residues, it elevates phosphotyrosine in transformed cells. The P47

gag-crk

oncoprotein contains SH2 and SH3 domains, which are conserved in several proteins involved in signal transduction, including nonreceptor tyrosine kinases. P47

gag-crk

bound in vitro to phosphotyrosine-containing proteins from
crk
-transformed cells and from cells transformed by oncogenic tyrosine kinases. The association between P47

gag-crk

and p60

v-
src

, a phosphotyrosine-containing protein, was abolished by dephosphorylation of p60

v-
src

. This suggests that the SH2 and SH3 regions function to regulate protein interactions in a phosphotyrosine-dependent manner.
Genetic Differences in the Ethanol Sensitivity of GABA
A
Receptors Expressed in
Xenopus
Oocytes
Authors: Wafford K. A. , Burnett D. M. , Dunwiddie T. V. , Harris R. A.
Published: October 2006

Animal lines selected for differences in drug sensitivity can be used to help determine the molecular basis of drug action. Long-sleep (LS) and short-sleep (SS) mice differ markedly in their genetic sensitivity to ethanol. To investigate the molecular basis for this difference, mRNA from brains of LS and SS mice was expressed in
Xenopus
oocytes and the ethanol sensitivity of gamma-aminobutyric acid A (GABA
A
)- and
N
-methyl D-aspartate (NMDA)-activated ion channels was tested. Ethanol facilitated GABA responses in oocytes injected with mRNA from LS mice but antagonized responses in oocytes injected with mRNA from SS animals. Ethanol inhibited NMDA responses equally in the two lines. Thus, genes coding for the GABAA receptor or associated proteins may be critical determinants of individual differences in ethanol sensitivity.
Expression of T Cell Antigen Receptor Heterodimers in a Lipid-Linked Form
Authors: Lin Augustine Y. , Devaux Brigitte , Green Adrienne , Sagerström Charles , Elliott John F. , Davis Mark M.
Published: October 2006

The interaction of the T cell receptor for antigen (TCR) with its antigen-major histocompatibility complex ligand is difficult to study because both are cell surface multimers. The TCR consists of two chains (alpha and beta) that are complexed to the five or more nonpolymorphic CD3 polypeptides. A soluble form of the TCR was engineered by replacing the carboxyl termini of alpha and beta with signal sequences from lipid-linked proteins, making them susceptible to enzymatic cleavage. In this manner, TCR heterodimers can be expressed independently of the CD3 polypeptides and in significant quantities (0.5 milligram per week). This technique seems generalizable to biochemical and structural studies of many other cell surface molecules as well.
Flip and Flop: A Cell-Specific Functional Switch in Glutamate-Operated Channels of the CNS
Authors: Sommer Bernd , Keinänen Kari , Verdoorn Todd A. , Wisden William , Burnashev Nail , Herb Anne , Kohler Martin , Takagi Tamaki , Sakmann Bert , Seeburg Peter H.
Published: October 2006

In the central nervous system (CNS), the principal mediators of fast synaptic excitatory neurotransmission are L-glutamate-gated ion channels that are responsive to the glutamate agonist α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA). In each member of a family of four abundant AMPA receptors, a small segment preceding the predicted fourth transmembrane region has been shown to exist in two versions with different amino acid sequences. These modules, designated "flip" and "flop," are encoded by adjacent exons of the receptor genes and impart different pharmacological and kinetic properties on currents evoked by L-glutamate or AMPA, but not those evoked by kainate. For each receptor, the alternatively spliced messenger RNAs show distinct expression patterns in rat brain, particularly in the CA1 and CA3 fields of the hippocampus. These results identify a switch in the molecular and functional properties of glutamate receptors operated by alternative splicing.
Living Polymers: A Tool in Studies of Ions and Ion-Pairs
Authors: Szwarc M.
Published: October 2006

Studies of living polymers have greatly enriched our knowledge of the behavior of ions and ion-pairs in organic media. Future investigations will lead to more detailed knowledge of these interesting species. Especially, intramolecular associations or intramolecular solvation by the polymer chains provide promising field for additional studies, and one example of such phenomena was reported recently by Fisher and Szwarc.
DDT Residues in Marine Phytoplankton: Increase from 1955 to 1969
Authors: Cox James L.
Published: October 2006

Phytoplankton samples collected in Monterey Bay, California, from 1955 to 1969 contained compounds identified as
p
,
p
′-DDT,
p
,
p
′-DDD, and
p
,
p
′-DDE. Total concentrations of these compounds were approximately three times greater in the later samples. Lower concentrations throughout the period were associated with higher densities of standing crop.
DDT Metabolites and Analogs: Ring Fission by
Hydrogenomonas
Authors: Focht D. D. , Alexander M.
Published: October 2006

A
Hydrogenomonas
cleaved one of the rings of
p
,
p
′-dichlorodiphenylmethane, a product of DDT metabolism, to yield
p
-chlorophenylacetate and further metabolized the latter compound. Products of microbial degradation of other diphenylmethanes were also identified. Substituents on the methylene-carbon and
para
-chloro substitution are critical factors governing resistance of DDT and related compounds to aerobic metabolism and decomposition by the bacterium.
Bistatic-Radar Observation of Long-Period, Directional Ocean-Wave Spectra with Loran A
Authors: Peterson Allen M. , Teague Calvin C. , Tyler G. Leonard
Published: October 2006

Bistatic-radar scattering from medium- to long-wavelength (80 to 200 meters) ocean waves has been observed with the use of loran A (1.85 megahertz) transmissions and a receiver located 280 kilometers away. The received echoes have been converted into a time-delay, Doppler-frequency map in which the effects of anisotropies in the ocean-wave spectra are clearly shown. The distribution of the echoes in delay-Doppler space is consistent with Bragg scattering from trains of dispersed ocean waves.
Lysopine and Octopine Promote Crown-Gall Tumor Growth in vivo
Authors: Lippincott James A. , Lippincott Barbara B.
Published: October 2006

Growth of tumors induced on primary leaves of bean plants by
Agrobacterium tumefaciens
was increased by the addition of lysopine and octopine. A detectable response was observed when as little as 1 microgram of these compounds was added per leaf, and the mean volume of the tumors was increased two- to threefold when greater amounts were applied. The specificity of the response and the unique association of these compounds with the tumors suggest that endogenous lysopine and octopine contribute to the growth characteristics of these tumors.
Cardiac Responses on the Visual Cliff in Prelocomotor Human Infants
Authors: Campos Joseph J. , Langer Alan , Krowitz Alice
Published: October 2006

Human infants younger than crawling age yielded reliable cardiac decelerations when placed directly atop the deep side of a visual cliff and generally nonsignificant changes when atop the shallow side. Distress was elicited less frequently on the deep side than on the shallow at these ages, in contrast to the behavior of older infants and other species. Prelocomotor infants thus can discriminate the two sides of the cliff, but not by means of distress at loss of optical support.
Hemagglutination Assay for Antigen and Antibody Associated with Viral Hepatitis
Authors: Vyas G. N. , Shulman N. R.
Published: October 2006

Hemagglutination assays are described for measuring hepatitis-associated Australia antigen and antibody. Red cells coated with isolated antigen, with chromic chloride as a coupling agent, are used for detection of antibodies. Detection of the antigen in serums depends on inhibition of hemagglutination. The test has the sensitivity and rapidity of the best tests available, is simpler to perform, and lends itself to large-scale screening of blood donors.
Bimodal Sedimenting Zones Due to Ligand-Mediated Interactions
Authors: Cann John R. , Goad Walter B.
Published: October 2006

Ligand-mediated association-dissociation reactions can give rise to band sedimentation patterns showing bimodal bands despite instantaneous establishment of equilibrium. Weaker interactions result in unimodal bands whose sedimentation coefficients decrease with time of sedimentation and in characteristic patterns of total ligand. The implications of these results for fundamental investigations of protein interactions and for conventional analytical applications of zone sedimentation and molecular sieve chromatography are considered.
Phenylthioacetate: A Useful Substrate for the Histochemical and Colorimetric Detection of Cholinesterase
Authors: Booth Gary M. , Metcalf Robert L.
Published: October 2006

Cholinesterase from frozen sections of honey bee (
Apis mellifera
. L.) brain hydrolyzes phenylthioacetate and acetylthiocholine to give virtually identical patterns of enzyme distribution with and without the use of paraoxon. In addition, phenylthioacetate is an economical substrate for in vitro and in vivo studies of cholinesterase. Phenylthioacetate offers the advantages of being easily synthesized and lipoid soluble, and appears to penetrate membranes easily.
Gibbon Fibrinopeptides: Identification of a Glycine-Serine Allelism at Position B-3
Authors: Mross George A. , Doolittle Russell F. , Roberts B. F.
Published: October 2006

The fibrinopeptides A and B of the gibbon (an Asian ape) have been characterized and their relation to other primate types examined. An allelic situation was discovered at location B-3; two of the gibbons studied had both glycine and serine at that position, whereas four others were homozygous for glycine.
Pre-Cretaceous Flowering Plants: Further Evidence from Utah
Authors: Tidwell William D. , Rushforth Samuel R. , Simper A. Daniel
Published: October 2006

Palm roots discovered in place in the Jurassic Arapien Shale Formation are further evidence for pre-Cretaceous flowering plants.
Lactosyl Ceramidosis: Catabolic Enzyme Defect of Glycosphingolipid Metabolism
Authors: Dawson Glyn , Stein Arthur O.
Published: October 2006

A 3-year-old Negro female showed clinical evidence of a neurovisceral storage disorder that has been characterized by the specific elevation of lactosyl ceramide in erythrocytes, plasma, bone marrow, urine sediment, liver biopsy, and brain biopsy. A galactosyl hydrolase deficiency was demonstrated by the inability to cleave lactosyl ceramide labeled with tritium in the terminal galactose. The enzyme deficiency may be the primary cause of this previously unreported sphingolipidosis.
Scanning Electron Microscopy of the Organ of Corti
Authors: Bredberg Göran , Lindeman Henrik H. , Ades Harlow W. , West Roger , Engström Hans
Published: October 2006

With the scanning electron microscope we have examined normal cochlear sensory epithelium of the guinea pig and cat and that damaged by noise. The studies demonstrate how the regular surface architecture of the organ of Corti is altered after exposure to noise. The changes include loss of sensory hairs, formation of giant hairs, and complete degeneration of circumscribed areas of the organ of Corti. Our method greatly reduces the artifacts.
Sexual Behavior of Male Cats after Administration of Parachlorophenylalanine
Authors: Zitrin Arthur , Beach Frank A. , Barchas Jack D. , Dement William C.
Published: October 2006

The behavior of 12 male cats was observed before and after six or eight daily injections of parachlorophenylalanine. Sexual performance was either unchanged or diminished; aggressive behavior was not seen. Serotonin concentrations in the brains were uniformly lowered.
Lunar Surface: Changes in 31 Months and Micrometeoroid Flux
Authors: Jaffe Leonard D.
Published: October 2006

Comparison of pictures of the lunar surface taken 31 months apart by Surveyor 3 and Apollo 12 show only one change in the areas disturbed by Surveyor: a 2-millimeter particle, in a footpad imprint, that may have fallen in from the rim or been kicked in by an approaching astronaut. Vertical walls 6 centimeters high did not collapse and dark ejecta remained dark. No meteorite craters as large as 1.5 millimeters in diameter were seen on a smooth soil surface 20 centimeters in diameter; this indicates a micrometeoroid flux lower than 4 × 10
-7
micrometeoroids per square meter-second at an energy equivalent to about 3 × 10
-8
gram at 20 kilometers per second. This flux is near the lower limit of previous determinations.
Neuraminidase Activity in HeLa Cells: Effect of Hydrocortisone
Authors: Carubelli R. , Griffin M. J.
Published: October 2006

Homogenates of HeLa cells contain neuraminidase activity. This enzyme is particle-bound, and it has a
p
H optimum of 4.2. Hydrocortisone-regulated cells contain two to three times as much neuraminidase as the corresponding controls. The hydrocortisone treatment also causes an increase in the cell content of β-glucuronidase and acid deoxyribonuclease.
How Did Venus Lose Its Angular Momentum?
Authors: Singer S. F.
Published: October 2006

Venus now has a retrograde and negligible spin, but it very likely started with a typical planetary spin: prograde and with a 10- to 20-hour period. The usually assumed mechanism of solar tidal friction is quite insufficient to remove this angular momentum. Instead, we postulate capture of a moonlike object from an initially retrograde orbit: it would despin Venus and suddenly transform the planet's rotational kinetic energy into internal heat, which would lead to volcanism and the liberation of large amounts of volatiles. The moon would disappear by crashing into the surface of Venus.
Antibodies That Impair Insulin Receptor Binding in an Unusual Diabetic Syndrome with Severe Insulin Resistance
Authors: Flier Jeffrey S. , Kahn C. Ronald , Roth Jesse , Bar Robert S.
Published: October 2006

Six patients with a unique form of diabetes associated with extreme insulin resistance have markedly reduced insulin binding to specific receptors on their circulating monocytes. When normal insulin receptors were exposed to serum or immunoglobulin fractions from three of these patients in vitro the specific binding defect was reproduced.
Heteropolypeptides from Poly-α-Cyanoglycine and Hydrogen Cyanide: A Model for the Origin of Proteins
Authors: Minard Robert , Yang William , Varma Pratibha , Nelson John , Matthews Clifford
Published: October 2006

Poly-α-cyanoglycine, a homopolymer synthesized from the
N
-carboxyanhydride of α-cyanoglycine, is converted by cumulative reactions of hydrogen cyanide to heteropolypeptides that can be hydrolyzed to protein amino acids, including glycine, alanine, valine, aspartic acid, and glutamic acid. These results are consistent with the hypothesis that the original heteropolypeptides on the earth arose spontaneously from hydrogen cyanide and water without the intervening formation of α-amino acids.
Electron Microscopy of Albumin Synthesis
Authors: Lin Chin-Tarng , Chang Jeffrey P.
Published: October 2006

Albumin molecules appeared to be synthesized in the light hepatocytes of rats by bound polysomes on rough endoplasmic reticulum and the nuclear envelope. The molecules were discharged directly into the cytosol, then to the external cellular spaces. This conclusion failed to support the current theory from biochemical studies that albumin is synthesized by bound ribosomes, discharged into the cisternae of rough endoplasmic reticulum, and transported to the smooth endoplasmic reticulum and then to the Golgi apparatus. In addition to the liver, positive synthetic activities were observed in the aorta, kidney, and hepatoma cells of rat. Earlier investigators have reported that only liver cells can synthesize albumin.
Presence of an SH2 Domain in the Actin-Binding Protein Tensin
Authors: Davis Samuel , Lu Michael L. , Lo Su Hao , Lin Shin , Butler James A. , Druker Brian J. , Roberts Thomas M. , An Qi , Chen Lan Bo
Published: October 2006

The molecular cloning of the complementary DNA coding for a 90-kilodalton fragment of tensin, an actin-binding component of focal contacts and other submembraneous cytoskeletal structures, is reported. The derived amino acid sequence revealed the presence of a Src homology 2 (SH2) domain. This domain is shared by a number of signal transduction proteins including nonreceptor tyrosine kinases such as Abl, Fps, Src, and Src family members, the transforming protein Crk, phospholipase C-γ1, PI-3 (phosphatidylinositol) kinase, and guanosine triphosphatase-activating protein (GAP). Like the SH2 domain found in Src, Crk, and Abl, the SH2 domain of tensin bound specifically to a number of phosphotyrosine-containing proteins from v-src-transformed cells. Tensin was also found to be phosphorylated on tyrosine residues. These findings suggest that by possessing both actin-binding and phosphotyrosine-binding activities and being itself a target for tyrosine kinases, tensin may link signal transduction pathways with the cytoskeleton.
Atomic Structure of FKBP-FK506, an Immunophilin-Immunosuppressant Complex
Authors: Van Duyne Gregory D. , Standaert Robert F. , Karplus P. Andrew , Schreiber Stuart L. , Clardy Jon
Published: October 2006

The structure of the human FK506 binding protein (FKBP), complexed with the immunosuppressant FK506, has been determined to 1.7 angstroms resolution by x-ray crystallography. The conformation of the protein changes little upon complexation, but the conformation of FK506 is markedly different in the bound and unbound forms. The drug's association with the protein involves five hydrogen bonds, a hydrophobic binding pocket lined with conserved aromatic residues, and an unusual carbonyl binding pocket. The nature of this complex has implications for the mechanism of rotamase catalysis and for the biological actions of FK506 and rapamycin.
Repression of Interferon Action: Induced Dedifferentiation of Embryonic Cells
Authors: Grossberg Sidney E. , Morahan Page S.
Published: October 2006

Cells cultured from young (6-day) chicken embryos differ from those of older (13-day) embryos in having a greater susceptibility to infection by certain viruses and a considerably lesser sensitivity to the action of interferon. These circumstances parallel those observed in the intact embryo. The addition of a small percentage of cells from young embryos alters the response of cells cultured from older embryos by increasing viral susceptibility sevenfold and decreasing sensitivity to interferon 25-fold. We postulate that a repressor which inhibits the expression of interferon in older embryonic cells is elaborated by cells from young embryos.
Paleolimnology of Late Quaternary Deposits: Seibold Site, North Dakota
Authors: Cvancara Alan M. , Clayton Lee , Bickley William B. , Jacob Arthur F. , Ashworth Allan C. , Brophy John A. , Shay C. T. , Delorme L. Denis , Lammers George E.
Published: October 2006

A unique late Quaternary lacustrine deposit has been discovered recently on the Missouri Coteau of North Dakota. A diverse, extremely well-preserved biota of more than 160 species has been recovered primarily from an organic mud deposited about 9500 years before the present. The lacustrine body shallowed gradually as the climate became drier.
Environmental Control of Photosynthetic Enhancement
Authors: Punnett Thomas
Published: October 2006

The transition from granular to homogeneous chloroplasts in vivo in
Egeria densa
caused by environmental conditions was paralleled by a decrease in photosynthetic enhancement from 30 percent to nearly zero. The drop in enhancement can be explained either by a change in the partitioning of light energy between the two photosystems or a change to a single photosystem.
Cells Capable of Colony Formation in the Peripheral Blood of Man
Authors: McCredie Kenneth B. , Hersh Evan M. , Freireich Emil J
Published: October 2006

Colony-forming cells have been found in the peripheral blood of man and have been grown in vitro by use of a soft agar gel technique. It has been possible to collect these cells with a blood-cell separator in numbers similar to those found in the peripheral circulation. Repeat leukapheresis of the same donor does not reduce the number of circulating colony-forming cells.
Protein-Metal Ion Binding Site: Determination with Proton Magnetic Resonance Spectroscopy
Authors: Rose P. I.
Published: October 2006

Proton magnetic resonance spectra of aqueous gelatin were analyzed with respect to composition and molecular interactions. Aqueous gelatin complexes cobaltous ions in the
p
D range of ∼3.5 to 7.5. Glutamyl and aspartyl side chains are shown to be the sites of binding.
Clouds of Venus: Evidence for Their Nature
Authors: Hansen James E. , Arking Albert
Published: October 2006

The linear polarization of sunlight multiply scattered by the atmosphere and cloud particles of Venus has been computed and compared with observations over the wavelength range from the ultraviolet to the infrared region. The following properties of the visible cloud layer are derived: the refractive index of the cloud particles is 1.45 ± 0.02 at a wavelength of 0.55 micron, and there is an indication of a slight decrease in the value from the ultraviolet to the near-infrared region; the mean particle radius is very near 1 micron, and most of the particles are spherical; the cloud layer occurs high in the atmosphere where the pressure is about 50 millibars (equivalent to an altitude of approximately 20 kilometers on the earth). The results for the index of refraction eliminate the possibility that the visible clouds are composed of pure water or ice.
Microbial Degradation of Organic Matter in the Deep Sea
Authors: Jannasch Holger W. , Eimhjellen Kjell , Wirsen Carl O. , Farmanfarmaian A.
Published: October 2006

Food materials from the sunken and recovered research submarine Alvin were found to be in a strikingly well-preserved state after exposure for more than 10 months to deep-sea conditions. Subsequent experiments substantiated this observation and indicated that rates of microbial degradation were 10 to 100 times slower in the deep sea than in controls under comparable temperatures.
Sulfur Isotopes in Swaziland System Barites and the Evolution of the Earth's Atmosphere
Authors: Perry Eugene C. , Monster Jan , Reimer Thomas
Published: October 2006

Sedimentary barites from the Swaziland System of South Africa (more than 3000 million years old) have sulfur-34 ratios that are enriched by only 2.5 per mil with respect to contemporary sulfides. To explain this small fractionation, it is proposed that oxygen pressure in the earth's atmosphere was very low and that local oxidation occurred in a photosynthetic layer of the ocean.
Stimulation in vitro with Protein Carrier of Antibodies against a Hapten
Authors: Sulica Andrei , Tarrab Rebeca , Sela Michael
Published: October 2006

Rabbits were immunized both with lysozyme and with dinitrophenylated bovine serum albumin. No antibodies against the dinitrophenyl hapten were produced when cell suspensions of their spleens were exposed in vitro to dinitrophenyl-ovalbumin, whereas a positive response was obtained with dinitrophenyl-lysozyme. Moreover, when spleen cells from rabbits previously immunized with dinitrophenyl-bovine serum albumin were exposed in vitro to bovine serum albumin alone, they produced antibodies against the dinitrophenyl hapten.
Narcotic Tolerance and Dependence: Lack of Relationship with Serotonin Turnover in the Brain
Authors: Cheney D. L. , Goldstein A. , Algeri S. , Costa E.
Published: October 2006

Serotonin turnover was measured in mouse brain by means of the conversion of radioactivity from labeled tryptophan into serotonin. Animals with a high degree of tolerance to and physical dependence on morphine did not differ from control mice.