bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Mechanism of Red Cell "Sickling"
Authors: Murayama Makio
Published: October 2006

Precision scale models of sickle-cell hemoglobin molecules indicate that the genetic substitution of valine for glutamic acid at the 6th position in the two beta chains allows an intramolecular hydrophobic bond to form. This changes the conformation in such a way as to allow molecular stacking. Optical rotatory dispersion studies and the results of subjection of Hb S solution to temperature change and to propane are consistent with the presence of such a bond. Examination of sickled erythrocytes in a magnetic field and in polarized light indicates that the Hb S molecules are aligned in situ. Filaments interpreted as hollow cables of six Hb S monofilaments have been demonstrated by electron microscopy.
Morphology of Nascent Ziegler-Natta Polymers
Authors: Blais P. , Manley R. St. John
Published: October 2006

In the polymerization of α-olefins with heterogeneous Ziegler-Natta catalysts, the polymer is formed directly as long fibrillar units with folded chains. It is proposed that the fibrils are formed by the crystallization of polymer chains growing from the active sites on the catalyst surface, a process which is likened to root growth in whiskers.
Doppler Interpretation of Quasar Red Shifts
Authors: Zapolsky Harold S.
Published: October 2006

The hypothesis that the quasistellar sources (quasars) are local objects moving with velocities close to the speed of light is examined. Provided there is no observational cutoff on apparent bolometric magnitude for the quasars, the transverse Doppler effect leads to the expectation of fewer blue shifts than red shifts for an isotropic distribution of velocities. Such a distribution also yields a function N(
z
), the number of objects with red shift less than
z
which is not inconsistent with the present data. On the basis of two extreme assumptions concerning the origin of such rapidly moving sources, we computed curves of red shift plotted against magnitude. In particular, the curve obtained on the assumption that the quasars originated from an explosion in or nearby our own galaxy is in as good agreement with the observations as the curve of cosmological red shift plotted against magnitude.
High-Speed Scanning in Human Memory
Authors: Sternberg Saul
Published: October 2006

When subjects judge whether a test symbol is contained in a short memorized sequence of symbols, their mean reaction-time increases linearly with the length of the sequence. The linearity and slope of the function imply the existence of an internal serial-comparison process whose average rate is between 25 and 30 symbols per second.
Infrared Study of the Hydroxyl Bands in Clinoamphiboles
Authors: Burns Roger G. , Strens Roger G. J.
Published: October 2006

Sharp single peaks in the fundamental and first-overtone bands of the O-H stretching vibration in pure Mg
2+
and Fe
2+
amphiboles split into a maximum of four sharp peaks, corresponding to hydroxyl groups linked to 3 Fe, 2 Fe + Mg, 2 Mg + Fe, and 3 Mg, in mixed Fe
2+
-Mg
2+
amphiboles. Within any one solid-solution series, the frequencies of these peaks can be correlated with the electronegativity of ions in the M
1
and M
3
positions, and differences between series can be correlated with the size of ions in the M
4
position. The O-H vector lies approximately normal to
z
in the (010) plane. The distribution of Fe
2+
and Mg
2+
ions between the (M
1
,M
3
) and (M
2
M
4
) positions in the cummingtonite-grunerite series, and between the (M
1
,M
3
) and M
2
positions in the tremolite-ferroactinolite series, has also been estimated.
Butler, Missouri: An Unusual Iron Meteorite
Authors: Goldstein J. I.
Published: October 2006

The Butler iron meteorite has been found to have, with respect to other iron meteorites, an unusually high cobalt content (1.4 percent by weight), unusually high germanium contents in the kamacite and the taenite phases, and an unusually low cooling rate (0.5°C/10
6
years). It is suggested that Butler formed in a different environment from that of the rest of the iron meteorites.
Polysomes Extracted from
Escherichia coli
by Freeze-Thaw-Lysozyme Lysis
Authors: Ron Eliora Z. , Kohler Robert E. , Davis Bernard D.
Published: October 2006

Polysomes can be extracted from
Escherichia coli
by freezing and thawing in the presence of lysozyme, followed by treatment with sodium deoxycholate. The method is simple and convenient; the yields consistently high.
Contractile Cells in Human Seminiferous Tubules
Authors: Ross Michael H. , Long Irl R.
Published: October 2006

Electron microscopic study of the peritubular connective tissue in human testis reveals the presence of "contractile-type" cells rather than of typical fibrocytes. Their cytoplasm has numerous fine filaments and other components characteristic of smooth muscle cells. The rough-surfaced endoplasmic reticulum, however, is relatively prominent. In some instances, the nuclear surface appears scalloped or folded, and the cell surface presents an irregular profile, similar to that of contracted cells.
"Copulation-Reward Site" in the Posterior Hypothalamus
Authors: Caggiula Anthony R. , Hoebel Bartley G.
Published: October 2006

Posterior hypothalamic self-stimulation of male rats, in which monopolar, platinum electrodes had been bilaterally implanted, increased after systemic injection of testosterone. Constant stimulation to the same site elicited immediate copulation with estrous female rats. During constant stimulation, males would press a bar to open a door for access to females. Even after ejaculation, males continued to open the door and to display sexual activity until stimulation terminated. Posterior hypothalamic stimulation is like normal sexual stimulation; it is rewarding, the reward varies with the amount of the sex hormone, and it elicits motivated copulation.
Cucurbitacins: Specific Insect Attractants in Cucurbitaceae
Authors: Chambliss Oyette L. , Jones Charles M.
Published: October 2006

In vivo studies of cucurbitacins, the bitter principles present in Cucurbitaceae, indicated a quantitative relation between the concentrations of cucurbitacin in the plant and the degree of insect feeding. In vitro studies demonstrated the attractiveness of these compounds when they were separated from influences of other components of the host plants.
Sleep Deprivation and Brain Acetylcholine
Authors: Bowers Malcolm B. , Hartmann Ernest L. , Freedman Daniel X.
Published: October 2006

Rats deprived of D-state sleep (and, to some extent, of slow-wave sleep) for 96 hours show a significant fall in brain acetylcholine in the telencephalon; there were no significant changes in the diencephalon and brain stem. Restraint stress and activity wheel stress produced no significant change in acetylcholine levels in any of these regions; the telencephalic response to sleep deprivation, therefore, cannot be attributed to nonspecific stress. The effects of D-state deprivation and the psychoactive anticholinergic drugs on telencephalic acetylcholine levels are similar.
Infrared Analysis of Rat Bone: Age Dependency of Amorphous and Crystalline Mineral Fractions
Authors: Termine John D. , Posner Aaron S.
Published: October 2006

Quantitative infrared spectrophotometric analysis of whole femurs from male rats demonstrates that amorphous calcium phosphate is a major component of bone mineral. The amount of amorphous calcium phosphate in whole bone decreases while the crystalline bone apatite increases during early stages of bone formation. Mature rat bone contains constant levels of both amorphous and crystalline calcium phosphate.
Hemoglobins in Sheep: Multiple Differences in Amino Acid Sequences of Three Beta-Chains and Possible Origins
Authors: Boyer Samuel H. , Hathaway Peter , Pascasio Flora , Orton Charlene , Bordley James , Naughton Michael A.
Published: October 2006

Among the three adult sheep hemoglobins (A, B, and C), two (A and B) are reportedly products of alleles. The β-chains of A and B differ by at least seven scattered amino acid residues whereas the β-sequence of C differs from A by at least 16 residues and from B by at least 21 residues. These changes suggest that the origin of C-β antedated the divergence of A and B. Five shared differences between A-β and C-β with respect to B-β can be interpreted as the result of selective advantage in favor of B. A complex of additional mechanisms has possibly been involved in maintaining the A-B-C porymorphism.
Interaction of Cortex and Superior Colliculus in Mediation of Visually Guided Behavior in the Cat
Authors: Sprague James M.
Published: October 2006

Total contralateral hemianopia follows unilateral removal of the entire occipito-temporal neocortex in the cat. This deficit is classically ascribed to interruption of visual radiations serving cortical function ("cortical blindness") and is considered permanent. Return of vision to the hemianopic field after subsequent removal of the superior colliculus contralateral to the cortical lesion demonstrates that neither assumption is correct. The initial hemianopia is apparently due to depression of function of the colliculus ipsilateral to the cortical lesion, a depression maintained by influx of inhibition from the crossed colliculus. Thus, removal of the contralateral tectum, or splitting of the collicular commissure, abolishes this inhibition and allows the return of function in the ipsilateral colliculus, and with it the recovery from hemianopia. These findings emphasize that visually guided behavior is mediated at both cortical and midbrain levels, and that there is a marked interaction between these sites.
Activation of T Cells by a Tyrosine Kinase Activation Domain in the Cytoplasmic Tail of CD3 ε
Authors: Letourneur François , Klausner Richard D.
Published: October 2006

The multichain T cell antigen receptor functions by interacting with and activating one or more nonreceptor tyrosine kinases. The cytoplasmic tail of the ζ chain can activate T cells independently of the rest of the receptor complex. The function of the remaining invariant CD3 chains remains unknown. A 22-amino acid region of the cytoplasmic tail of CD3 ε was also able to independently activate T cells. Stimulation of T cells by means of the cytoplasmic tails of either ζ or CD3 ε resulted in quantitatively distinct patterns of tyrosine phosphorylation, suggesting activation of different biochemical pathways.
Structure of Transcription Elongation Complexes in Vivo
Authors: Kainz Mark , Roberts Jeffrey
Published: October 2006

The opening of duplex DNA in the elongation phase of transcription by
Escherichia coli
RNA polymerase in vivo was detected at a regulatory site where a prolonged pause in transcription occurs. Single-stranded DNA in the transcription bubble was identified by its reactivity with potassium permanganate (KMnO
4
). The elongation structure in vivo was similar to that of transcription complexes made in vitro with some differences. The observed reactivity to KMnO
4
of the DNA template strand was consistent with the existence of an RNA-DNA hybrid of about 12 nucleotides.
Turbulent-Gas Chromatography
Authors: Giddings J. Calvin , Manwaring William A. , Myers Marcus N.
Published: October 2006

Turbulent flow in gas chromatography was achieved and its effect was studied with high-speed, high-pressure equipment. A gas-solid capillary and several packed columns were used. The onset of turbulence was associated with abrupt decrease in peak width in the capillary and gradual leveling off and decrease in the packed columns. The existence of separation under turbulent conditions was shown. The potential of the method was demonstrated by its short elution times and rapid generation of theoretical plates.
Purification and Reconstitution of the Periodic Fibril and Unit Structure of Human Amyloid
Authors: Glenner George G. , Bladen Howard A.
Published: October 2006

Extraction with alkaline sodium glycinate of the periodic fibril and unit structure of human amyloid and subsequent acidification of the extract provided a method for the purification as well as for the reconstitution of the periodic rod and of the unit structure. Guanidine completely solubilized and irreversibly dissociated both the rod and the unit structure of the human amyloid fibril.
Anteroventral Cochlear Nucleus: Wave Forms of Extracellularly Recorded Spike Potentials
Authors: Pfeiffer Russell R.
Published: October 2006

Analysis of wave forms of spike potentials from neurons in the anteroventral cochlear nucleus indicates that the spikes are composed of three components. Two appear to be postsynaptic events, and one appears to be presynaptic and to be related to the calyces of Held found in that part of the nucleus.
Light Reaction in Green Plant Photosynthesis: A Method of Study
Authors: Arnold William
Published: October 2006

Frozen green plants (
Chlorella
) carry out a photoreaction which can be assayed by measuring the light produced when the sample is heated. Heating at a rate of several degrees per second gives a measurable signal which shows that green plants can store energy at very low temperatures. The absorption cross section for the unit which carries out the photoreaction is several hundred times larger than that for one chlorophyll molecule, an indication that these are the "photosynthetic units" of photosynthesis.
Antimicrobial Specificity of Leukocyte Lysosomal Cationic Proteins
Authors: Zeya H. I. , Spitznagel J. K.
Published: October 2006

Differences in antimicrobial specificities against
Staphylococcus aureus
,
Streptococcus faecalis
(group D), and
Proteus vulgaris
exist among the electrophoretically separable components of lysosomal cationic proteins of polymorphonuclear leukocytes.
Segregation of Sister Chromatids in Mammalian Cells
Authors: Lark K. G. , Consigli R. A. , Minocha H. C.
Published: October 2006

Segregation of sister chromatids in embryonic mouse cells in primary tissue culture is not random. In mitosis those chromatids replicated on a DNA template synthesized during the preceding division cycle are separated from those constructed on a template synthesized two division cycles previously. Segregation in cells of the Chinese hamster follows a similar, but less pronounced, pattern.
Anaphase Delay after Inhibition of Protein Synthesis between Late Prophase and Prometaphase
Authors: Cummins J. E. , Blomquist J. C. , Rusch H. P.
Published: October 2006

The relationship between protein synthesis and mitosis was studied in
Physarum polycephalum
, a plasmodial slime mold whose nuclear divisions are synchronous. Results of studies with actidione (cycloheximide), an inhibitor of protein synthesis, indicated that the essential structural proteins for mitosis and nuclear reconstruction were completed prior to the dissolution of the nucleolus in prophase. Proteins that determine the duration of the transition from metaphase to nuclear reconstruction were synthesized from late prophase to prometaphase. It is proposed that these proteins are concerned with the transformation of chemical energy into the mechanical work of mitosis.
Perineural Epithelium: A New Concept of its Role in the Integrity of the Peripheral Nervous System
Authors: Shanthaveerappa T. R. , Bourne Geoffrey H.
Published: October 2006

A multilayered, squamous-celled epithelial cell membrane covering the individual nerve fasciculi of the entire peripheral nervous system (both voluntary and autonomic) including the sensory and motor end organs has been demonstrated in various species of animals, including man. This membrane is the direct continuation of the pia-arachnoid mater from the central nervous system. Functional significance of this membrane, especially as a diffusion barrier and as a protector of the peripheral nervous system, is briefly discussed.
Identification of a Major Growth Factor for AIDS-Kaposi's Sarcoma Cells as Oncostatin M
Authors: Nair Bala Chandran , DeVico Anthony L. , Nakamura Shuji , Copeland Terry D. , Chen Ying , Patel Atul , O'Neil Trevor , Oroszlan Stephen , Gallo Robert C. , Sarngadharan M. G.
Published: October 2006

Conditioned medium from human T cell leukemia virus type 2 (HTLV-II)-infected T cells supports the growth and long-term culture of cells derived from acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma lesions (AIDS-KS cells). A protein of 30 kilodaltons was purified from conditioned medium that supports the growth of AIDS-KS cells. The amino-terminal sequence of this protein was identical to the amino-terminal sequence of Oncostatin M, a glycoprotein that inhibits the growth of a variety of cancer cells. Oncostatin M from conditioned medium stimulated a twofold increase in the growth of AIDS-KS cells at a concentration of less than 1 nanogram of the protein per milliliter of medium.
Socioeconomic Status and Psychiatric Disorders: The Causation-Selection Issue
Authors: Dohrenwend Bruce P. , Levav Itzhak , Shrout Patrick E. , Schwartz Sharon , Naveh Guedalia , Link Bruce G. , Skodol Andrew E. , Stueve Ann
Published: October 2006

Are inverse relations between psychiatric disorders and socioeconomic status due more to social causation (adversity and stress) or social selection (downward mobility of genetically predisposed)? This classical epidemiological issue is tested by focusing on ethnic status in relation to socioeconomic status. Ethnic status cannot be an effect of disorder because it is present at birth whereas socioeconomic status depends on educational and occupational attainment. A birth cohort sample of 4914 young, Israel-born adults of European and North African background was selected from the country's population register, screened, and diagnosed by psychiatrists. Results indicate that social selection may be more important for schizophrenia and that social causation may be more important for depression in women and for antisocial personality and substance use disorders in men.
Characterization of Peptides Bound to the Class I MHC Molecule HLA-A2.1 by Mass Spectrometry
Authors: Hunt Donald F. , Henderson Robert A. , Shabanowitz Jeffrey , Sakaguchi Kazuyasu , Michel Hanspeter , Sevilir Noelle , Cox Andrea L. , Appella Ettore , Engelhard Victor H.
Published: October 2006

Antigens recognized by T cells are expressed as peptides bound to major histocompatibility complex (MHC) molecules. Microcapillary high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry was used to fractionate and sequence subpicomolar amounts of peptides isolated from the MHC molecule HLA-A2.1. Of 200 different species quantitated, eight were sequenced and four were found in cellular proteins. All were nine residues long and shared a distinct structural motif. The sensitivity and speed of this approach should enhance the analysis of peptides from small quantities of virally infected and transformed cells as well as those associated with autoimmune disease states.
HLA-A2.1-Associated Peptides from a Mutant Cell Line: A Second Pathway of Antigen Presentation
Authors: Henderson Robert A. , Michel Hanspeter , Sakaguchi Kazuyasu , Shabanowitz Jeffrey , Appella Ettore , Hunt Donald F. , Engelhard Victor H.
Published: October 2006

Peptides extracted from HLA-A2.1 class I major histocompatibility complex (MHC) molecules expressed on the antigen processing mutant CEMx721.174.T2 were characterized by electrospray ionization-tandem mass spectrometry. Only seven dominant peptides were found, in contrast to over 200 associated with HLA-A2.1 on normal cells. These peptides were derived from the signal peptide domains of normal cellular proteins, were usually larger than nine residues, and were also associated with HLA-A2.1 in normal cells. These results suggest that proteolysis of signal peptide domains in the endoplasmic reticulum is a second mechanism for processing and presentation of peptides for association with class I molecules.
Biosynthesis of the Morphine Alkaloids
Authors: Kirby G. W.
Published: October 2006

Tracer experiments, supported throughout by the analogous chemical transformations, have firmly established the biosynthetic sequence tyrosine → norlaudanosoline → reticuline → salutaridine → salutaridinol-I → thebaine → codeine → morphine in
Papaver somniferum
. In general, the farther a precursor lies along this sequence, the more efficient its conversion to morphine in the intact plant. Several intermediates remain to be discovered, such as those lying between tyrosine and norlaudanosoline and between thebaine and codeine. Proof that morphine is made only by the reticuline-salutaridine route is still lacking and would require a careful comparison of the rate of morphine synthesis with the turnover rates for the various intermediates. More importantly, detailed knowledge of the mechanism of each biochemical step can come only with isolation of the enzyme system involved. The chemical oxidation of (—)-reticuline, to give salutaridine, can only be accomplished in very low (0.02 percent) yield, whereas, even with whole plants, the biological incorporation of reticuline into the morphine alkaloids can reach 8 percent. One would like to know just how an enzyme system directs the oxidative cyclization of reticuline in the desired sense.

Kleinschmidt and Mothes and Fairbairn and Wassel have shown that the latex isolated from opium poppies is capable of transforming tyrosine into morphine. Perhaps further work with opium latex will provide the key to the remaining problems of morphine biosynthesis.
Lateral Hypothalamus: Hoarding Behavior Elicited by Electrical Stimulation
Authors: Herberg L. J. , Blundell J. E.
Published: October 2006

Electrical stimulation of those points in the lateral hypothalamic area of the brain that promote feeding, but not of other points, elicited intense hoarding activity in satiated rats, similar to that produced by long-term food deprivation. This result suggests that hoarding of food is organized by a hypothalamic drive mechanism sensitive to the effects of long-term nutritional depletion.
Keto-Aldehydes and Cell Division
Authors: Szent-Györgyi A. , Együd L. G. , McLaughlin Jane A.
Published: October 2006

Many problems are left open in this article. Its publication may be excused by the suffering cancer causes, which urges the researcher to publish as soon as he thinks he may have found a new trail, which also may be taken by others. What emerges clearly is that SH groups, with their specific reactivities, offer a hopeful target in the search for cancerostatic substances, among which the natural repressor of cell division may hold out the most promise. The glyoxal derivatives also have antiviral properties and may be in the center of a hitherto unknown system of equilibria which deserves a thorough study. The low molecular weight of the glyoxal derivative reported justifies the hope of an early clarification of its structure, as well as its synthesis.
Rates of Surficial Rock Creep on Hillslopes in Western Colorado
Authors: Schumm S. A.
Published: October 2006

The average rate of downslope movement of rock fragments on shale hillslopes is directly proportional to the sine of the slope angle or that component of the gravitational force which acts parallel to the hillslope. The rates of surficial rock creep range from a few millimeters per year on a 3-degree slope to almost 70 millimeters per year on a 40-degree slope, but these rates vary with natural variations in soil characteristics and microclimate, as well as with accidental disturbances.
Plasma Membrane: Substructural Changes Correlated with Electrical Resistance and Pinocytosis
Authors: Brandt Philip W. , Freeman Alan R.
Published: October 2006

Inducers of pinocytosis in amoeba cause as much as a 50-fold decrease in the electrical resistance of the plasma membrane prior to the formation of the typical tunnels and vacuoles. In this state the thickness of the electron-transparent core or lamella of the unit membrane is at least twice as thick as that of the control. The changes in structure and resistance as well as the induction of pinocytosis are dependent on the initial external concentration of calcium. These changes are rapidly reversed when the concentration of calcium in the external medium is increased.
Neuromuscular Transmitter Substance in Insect Visceral Muscle
Authors: Brown B. E.
Published: October 2006

Stimulation of the nerves innervating the proctodeum (hindgut) of the cockroach
Periplaneta Americana
(L.) causes a slow-type, graded contraction of the longitudinal muscles. An unidentified substance, or substances, present in the foregut and hindgut, the specific activity of which is highest in the nerves innervating these organs, effects a similar contraction. This "gut-factor" is depleted from the hindgut after surgical section of the proctodeal nerves. None of Factors P
1
and P
2
, 5-hydroxytryptamine, acetylcholine, adrenaline, noradrenaline, α-aminobutyric acid or glutamate duplicates the pharmacological behavior of this substance. The active factor is associated with subcellular particles that require centrifugal forces of approximately 1,000,000
g
-min for sedimentation. The substance is inactivated in homogenates of gut tissue in the absence of suitable precautions. It is proposed that the "gut-factor" functions as an excitatory neuromuscular transmitter substance in insect visceral muscle.
Indium as an Impurity in Ancient Western Mexican Tin and Bronze Artifacts and in Local Tin Ore
Authors: Caley Earle R. , Easby Dudley T.
Published: October 2006

The presence of indium in a nodule of cassiterite from the State of Guerrero increases the probability that ancient tin and bronze artifacts from Guerrero, which contain indium as an impurity, were made locally from metal extracted from local tin ore.
Biographical Predictors of Scientific Performance
Authors: Taylor Calvin W. , Ellison Robert L.
Published: October 2006

The biographical approach to the identification of scientific talent has shown significant results in a variety of situations which included different laboratories, fields of specialization, and age groups. Much remains to be accomplished, however. The biographical approach needs to be validated in other organizational settings employing relevant criteria. Although this kind of research is being initiated, a number of studies are needed to define the advantages and limitations. The use of biographical information to identify the creative and other talents of executives, composers, administrators, and artists has been largely unexplored. Furthermore, the meaning of the biographical items has not been correlated with existing psychological theory and knowledge. All evidence to date indicates that the investigation of biographical information and its relationship to various criteria of performance and other psychological measures is a rapidly expanding area of investigation which will make further contributions to the identification of talent in a variety of fields.
Carbon Isotope Composition of Carbonaceous Matter from the Precambrian of the Witwatersrand System
Authors: Hoefs Jochen , Schidlowski Manfred
Published: October 2006

Polymerized hydrocarbons occurring in the gold-uranium conglomerates of the Witwatersrand System (South Africa) show δC
13
values between —22.4 and —32.8 per mille, their isotopic composition thus falling into the range of sedimentary organic carbon. Accordingly, organic derivation of the material seems very probable. This conclusion is consistent with a model of the existence of organic evolution and biologic activity in times certainly older than 2.15 × 10
9
years.
Crayfish Muscle: Permeability to Sodium Induced by Calcium Depletion
Authors: Reuben John P. , Brandt Philip W. , Girardier Lucien , Grundfest Harry
Published: October 2006

Membrane of crayfish muscle fibers becomes selectively permeable to sodium when the calcium concentration of the bathing medium is reduced. Removal of calcium or its reduction below 1 or 2 millimole per liter causes large transient depolarizations up to 70 millivolts in amplitude. They resemble prolonged action potentials and occur only in the presence of sodium. The responses are abolished when tris(hydroxymethyl)aminomethane or lithium is substituted for sodium, and are blocked by tetrodotoxin even in the presence of sodium.
Chromosomal Damage in Human Leukocytes Induced by Lysergic Acid Diethylamide
Authors: Cohen Maimon M. , Marinello Michelle J. , Back Nathan
Published: October 2006

Addition of lysergic acid diethylamide to cultured human leukocytes resulted in a marked increase of chromosomal abnormalities. The distribution of chromosome breaks deviated significantly from random, with an accumulation of aberrations in chromosome No. 1. Cytogenetic investigation of a patient extensively treated with this drug over a 4-year period for paranoid schizophrenia showed a similar increase in chromosomal damage.
Diffusion of Water in Zeolites
Authors: Parravano Carlo , Baldeschwieler J. D. , Boudart Michel
Published: October 2006

The self-diffusion coefficient
D
of water occluded in samples of near-faujasite has been determined by pulsed field-gradient spin-echo nuclear magnetic resonance. The value of
D
in square centimeters per second × 10
5
at 30°C is 1.34, 1.65, and 1.88 in the following zeolites, respectively: Na
X
, Ca
X
, and Ca
Y
(
X
and
Y
being an indication of ratio of silicon to aluminum in the zeolites). By comparison, the value of
D
in pure water at 30°C is 2.5 × 10
-5
cm
2
/sec. Arrhenius activation energies for
D
are 6.9, 6.8, and 5.6 kilocalories per mole, respectively, for the three faujasites and 5.0 kcal/mole for pure water. Thus, there appears to be little difference in diffusion behavior between free water and water occluded in faujasite.
The Updating of the Representation of Visual Space in Parietal Cortex by Intended Eye Movements
Authors: Duhamel Jean-René , Colby Carol L. , Goldberg Michael E.
Published: October 2006

Every eye movement produces a shift in the visual image on the retina. The receptive field, or retinal response area, of an individual visual neuron moves with the eyes so that after an eye movement it covers a new portion of visual space. For some parietal neurons, the location of the receptive field is shown to shift transiently before an eye movement. In addition, nearly all parietal neurons respond when an eye movement brings the site of a previously flashed stimulus into the receptive field. Parietal cortex both anticipates the retinal consequences of eye movements and updates the retinal coordinates of remembered stimuli to generate a continuously accurate representation of visual space.
Gap Domains Responsible for Ras P21-Dependent Inhibition of Muscarinic Atrial K
+
Channel Currents
Authors: Martin George A. , Yatani Atsuko , Clark Robin , Conroy Leah , Polakis Paul , Brown Arthur M. , McCormick Frank
Published: October 2006

The interaction between the low molecular weight G protein ras p21 and a guanosine triphosphatase activating protein (GAP) uncouples a heterotrimeric G protein (G
k
) from muscarinic receptors. Through the use of isolated atrial cell membranes and genetically engineered GAP deletion mutants, the src homology regions (SH2-SH3) at the amino terminus of GAP have been identified as the domains responsible for this effect. Deletion of the domain required to stimulate the guanosine triphosphatase activity of ras p21 relieves the requirement for ras p21 in this system. A model is presented that suggests that ras p21 induces a conformational change in GAP, which allows the SH2-SH3 regions of GAP to function.
Hominid Humeral Fragment from Early Pleistocene of Northwestern Kenya
Authors: Patterson Bryan , Howells W. W.
Published: October 2006

The distal end of a hominoid humerus was recovered from early Pleistocene sediments in the Kanapoi drainage near the southern end of Lake Rudolf. Lava capping the sediments yielded a potassium/argon date of 2.5 million years. The fragment can be distinguished on inspection from gorilla and orangutan; discriminate analysis of humeri of
Homo
and
Pan
assigns it as hominid. From other evidence we consider it more likely to represent
Australopithecus s.s.
than
Paranthropus
.
Cytokinins in the Soluble RNA of Plant Tissues
Authors: Hall Ross H. , Csonka Lilla , David Harold , McLennan Barry
Published: October 2006

The cytokinin, N
6
-(Δ
2
-isopentenyl)adenosine occurs in the soluble RNA of yeast and mammalian tissue and has now been detected in plant soluble RNA. A hydroxylated derivative of this cytokinin 6-(
cis
-4-hydroxy-3-methylbut-2-enylamino)-9-β-D-ribofuranosylpurine has also been identified as a constituent of plant soluble RNA.
Rabbit Lactate Dehydrogenase Isozymes: Effect of
p
H on Activity
Authors: Fritz Paul J.
Published: October 2006

The ability of lactate dehydrogenase isozyme five from rabbit skeletal muscle to catalyze pyruvate reduction is extremely sensitive to changes of
p
H within the range of 6.2 to 7.8. The activity of lactate dehydrogenase isozyme one from rabbit heart is virtually unaffected by changes of
p
H within the same range. Isozyme five is activated by low concentrations of oxalacetate and inhibited by higher concentrations, but other substrates of the citric acid cycle have no effect.
The Spread of Western Science
Authors: Basalla George
Published: October 2006

There is no need to summarize the features of this simplified model, which describes the manner in which modern science was transmitted to the lands beyond Western Europe. The graph of Fig. 1 and the examples drawn from science in various lands should have made them clear. It may be in order, however, to reiterate that there is nothing about the phases of my model that is cosmically or metaphysically necessary. I am satisfied if my attempt will interest others to go beyond my crude analysis and make a systematic investigation of the diffusion of Western science throughout the world.

Such an investigation would include a comparative appraisal of the development of science in different national, cultural, and social settings and would mark the beginnings of truly comparative studies in the history and sociology of science. The present lack of comparative studies in these disciplines can be attributed to the widespread belief that science is strictly an international endeavor. In one sense this is true. As Sir Isaac Newton remarked in his Principia, "the descent of stones in Europe and in America" must both be explained by one set of physical laws. Yet, we cannot ignore the peculiar environment in which members of a national group of scientists are trained and carry on their research.

While I do not hold with the Nazi theorists that science is a direct reflection of the racial or national spirit, neither do I accept Chekhov's dictum that "there is no national science just as there is no national multiplication table. . . ." In emphasizing the international nature of scientific inquiry we have forgotten that science exists in a local social setting. If that setting does not decisively mold the conceptual growth of science, it can at least affect the number and types of individuals who are free to participate in the internal development of science. Perhaps the effect is more profound; only future scholarship can determine the depth of its influence/
How Long Is the Coast of Britain? Statistical Self-Similarity and Fractional Dimension
Authors: Mandelbrot Benoit
Published: October 2006

Geographical curves are so involved in their detail that their lengths are often infinite or, rather, undefinable. However, many are statistically "self-similar," meaning that each portion can be considered a reduced-scale image of the whole. In that case, the degree of complication can be described by a quantity
D
that has many properties of a "dimension," though it is fractional; that is, it exceeds the value unity associated with the ordinary, rectifiable, curves.
Field Ion Microscopical Imaging of Biomolecules
Authors: Müller Erwin W. , Rendulic Klaus D.
Published: October 2006

Specimen molecules are protected from field desorption by embedding them in a platinum matrix, with the use of electrolytic codeposition on tungsten tips. High-resolution helium ion images are obtained when the biomolecules are exposed during gradual removal of surface layers by controlled field evaporation. Structured images of individual molecules of coenzyme I and vitamin B12are seen.
Food and Water Intake after Intrahypothalamic Injections of Carbachol in the Rabbit
Authors: Sommer Sally R. , Novin Donald , LeVine Mark
Published: October 2006

Direct chemical stimulation with carbachol in the hypothalamus of the rabbit caused a significant increase in food intake, as a function of place stimulated and concentration. Lower doses of carbachol injected near the supraoptic nucleus produced an increase in drinking without an increase in eating.
Lack of End-Product Inhibition and Repression of Leucine Synthesis in a Strain of
Salmonella typhimurium
Authors: Calvo Rita A. , Calvo Joseph M.
Published: October 2006

Mutants of
Salmonella
have been isolated which lack either end-product inhibition or repression of leucine biosynthesis. In a minimal salts-glucose medium, growth is not impaired by the lack of either control mechanism alone. The loss of both control mechanisms, however, leads to a 43 percent reduction in cell yield and a 1.5-fold reduction in the growth rate.
Lambda Chains in Cold Agglutinins
Authors: Feizi Ten
Published: October 2006

Type L light chains have been found in the cold agglutinins in the serums of three patients with chronic hemolytic anemia. Although two of these cold agglutinins are unusual in that they do not have specificity to I or i red-cell antigens (one of these has, in addition, cryoglobulin property), the third is a cold agglutinin of I specificity. Previously reported cold agglutinins from such patients have all been of type K; this is the first report of type L cold agglutinins associated with chronic hemolytic anemia.
Project Hindsight
Authors: Sherwin Chalmers W. , Isenson Raymond S.
Published: October 2006

Recently developed weapon systems were compared with systems of similar function in use 10 to 20 years earlier. The most significant finding was that the improvement in performance or reduction in cost is largely the synergistic effect of a large number of scientific and technological innovations, of which only about 10 percent had been made at the time the earlier system was designed. The common scientific and technological base of the systems was not analyzed. Of the innovations, or Events, 9 percent were classified as science and 91 percent as technology. Ninety-five percent of all Events were funded by the defense sector. Nearly 95 percent were motivated by a recognized defense need. Only 0.3 percent came from undirected science. The results of the study do not call in question the value of undirected science on the 50-year-or-more time scale. In light of our finding that 5 to 10 years are often required before even a piece of highly applied research is "fitted in" as an effective contributing member of a large assembly of other Events, it is not surprising that "fragments" of undirected science are infrequently utilized on even a 20-year time scale. The most obvious way in which undirected science appears to enter into technology and utilization on a substantial scale seems to be in the compressed, highly organized form of a well-established, clearly expressed general theory, or in the evaluated, ordered knowledge of handbooks, textbooks, and university courses.
Sleep: The Effect of Electroconvulsive Shock in Cats Deprived of REM Sleep
Authors: Cohen Harry B. , Duncan Richard F. , Dement William C.
Published: October 2006

Three cats were deprived of rapid-eye-movement (REM) sleep for 10 days, and three were deprived for 12 days. All cats received an electrically induced convulsion on each of the last 3 days of deprivation, as well as on the 1st recovery day just prior to sleep onset. As controls, four cats were deprived of REM sleep for 12 days and one was deprived for 10 days; the controls received no convulsions. Compensatory increases in REM sleep during recovery days were present in the convulsed animals, but were substantially lower than the recovery increases of control animals. During recovery REM sleep, convulsed cats did not display the exaggerated bursts of eye movements and body twitches seen in the nonconvulsed controls.
Constructing Proteins by Dovetailing Unprotected Synthetic Peptides: Backbone-Engineered HIV Protease
Authors: Schnölzer Martina , Kent Stephen B. H.
Published: October 2006

Backbone-engineered HIV-1 protease was prepared by a total chemical synthesis approach that combines the act of joining two peptides with the generation of an analog structure. Unprotected synthetic peptide segments corresponding to the two halves of the HIV-1 protease monomer polypeptide chain were joined cleanly and in high yield through unique mutually reactive functional groups, one on each segment. Ligation was performed in 6 molar guanidine hydrochloride, thus circumventing limited solubility of protected peptide segments, the principal problem of the classical approach to the chemical synthesis of proteins. The resulting fully active HIV-1 protease analog contained a thioester replacement for the natural peptide bond between Gly
51
-Gly
52
in each of the two active site flaps, a region known to be highly sensitive to mutational changes of amino acid side chains.
Motions of the Earth's Core and Mantle, and Variations of the Main Geomagnetic Field
Authors: Hide Raymond
Published: October 2006

Theoretical work on the magnetohydrodynamics of the earth's liquid core indicates (a) that horizontal variations in the properties of the core-mantle interface that would escape detection by modern seismological methods might nevertheless produce measurable geomagnetic effects; (b) that the rate of drift, relative to the earth's surface, of nonaxisymmetric features of the main geomagnetic field might be much faster than the average zonal speed of hydrodynamic motion of core material relative to the surrounding mantle; and (c) why magnetic astronomical bodies usually rotate. Among the consequences of (a) and (b) are the possibilities that (i) the shortest interval of time that can be resolved in paleomagnetic studies of the geocentric axial dipole component of the earth's magnetic field might be very much longer than the value often assumed by many paleomagnetic workers, (ii) reversals in sign of the geomagnetic dipole might be expected to show some degree of correlation with processes due to motions in the mantle (for example, tectonic activity, polar wandering), and (iii) variations in the length of the day that have hitherto been tentatively attributed to core motions may be due to some other cause.
Chlamydomonas reinhardi
: Heterozygous Diploid Strains
Authors: Ebersold W. T.
Published: October 2006

Zygotes of the unicellular green alga
Chlamydomonas reinhardi
occasionally divide mitotically to give rise to stable diploid vegetative strains. As well as by their mode of origin, these strains are distinguished from haploids by cell and nuclear size, DNA content per nucleus, and chromosome number. Diploid strains heterozygous for a variety of mutant genes are phenotypically wild type and mating-type minus. Thus these mutant genes are recessive to their wild-type alleles, and the mating-type-minus is dominant over the mating-type-plus allele.
Effects of Thiopental Sedation on Learning and Memory
Authors: Osborn Anne G. , Bunker John P. , Cooper Leslie M. , Frank Gilbert S. , Hilgard Ernest R.
Published: October 2006

Subjects who were administered thiopental showed a loss of memory for events discussed while they were under sedation. We tested the subjects for recognition memory of pictures and recall of associated pairs of letters and words, and found that the subsequent memory loss was correlated with the concentration of thiopental in the venous blood at the time the material was learned. Retention did not appear to be state-dependent because the subject, while under sedation, could recall material learned prior to sedation, and because recall was not facilitated by reinstatement of the sedation.
New Method for the Detection of Light Deflection by Solar Gravity
Authors: Shapiro Irwin I.
Published: October 2006

The prediction of Einstein's theory of general relativity that light will be deflected by the sun may be tested by sending radio waves from the earth to Venus or Mercury when either passes behind the sun and detecting the echoes with a radar interferometer.
Cochlear Function and Sodium and Potassium Activated Adenosine Triphosphatase
Authors: Kuijpers W. , van der Vleuten A. C. , Bonting S. L.
Published: October 2006

The maintenance of the cation gradients between endolymph and perilymph in the cochlea requires the operation of a cation pump. An adenosine triphosphatase system activated by sodium and potassium is present in high activity in the cochlear membranes (tegmentum vasculosum and stria vascularis). The cochlear microphonic potential is inhibited by perilymphatic perfusion of ouabain and erythrophleine. Since the microphonic potential depends on the high concentration of potassium ions in the endolymph, our findings strongly suggest the operation of an adenosine triphosphatase cation pump system activated by sodium and potassium, in the generation of cochlear cation gradients.
Paleozoic Sedimentary Rocks in Oaxaca, Mexico
Authors: Pantoja-Alor Jerjes , Robison Richard A.
Published: October 2006

Fossiliferous Cambrian, Ordovician, Mississippian, and Pennsylvanian rocks, never before found in southern Mexico, have been discovered in the Nochixtlán region. Superjacent unfossiliferous sedimentary rocks may be Permian in age. Early Paleozoic and late Paleozoic intervals of marine sedimentation were bounded by intervals of positive tectonism and erosion.
Phase Changes in the Upper Mantle
Authors: Anderson Don L.
Published: October 2006

The C-region of the upper mantle has two transition regions 75 to 90 kilometers thick. In western North America these start at depths of 365 kilometers and 620 kilometers and involve velocity increases of about 9 to 10 percent. The locations of these transition regions, their general shape, and their thicknesses are consistent with, first, the transformation of magnesium-rich olivine to a spinel structure and, then, a further collapse of a material having approximately the properties of the component oxides. The velocity increases associated with each transition region are slightly less than predicted for the appropriate phase change. This can be interpreted in terms of an increasing fayalite content with depth. The location of the transition regions and the seismic velocities in their vicinity supply new information regarding the composition and temperature of the upper mantle. The depths of the transition regions are consistent with temperatures near 1500°C at 365 kilometers and 1900°C at 620 kilometers.
The Ginkgo, the Most Ancient Living Tree
Authors: Major Randolph T.
Published: October 2006

Fossil records clearly demonstrate that the group of trees known as Ginkgoales, of which today
Ginkgo biloba
is the sole living member, date back over 200 million years.
Ginkgo bilboa
itself is one of the oldest of living plants. It appears that the longevity of this tree and its long reproductive period are at least partially responsible for the persistence of the species. The resistance of these trees to pests such as insects, bacteria, viruses, and fungi has been studied. It is believed that their unusual resistance to pests accounts in part for the longevity of the trees and also, in turn, for the longevity of the species.
Insect Hormones: Alpha Ecdysone and 20-Hydroxyecdysone in Bracken Fern
Authors: Kaplanis J. N. , Thompson M. J. , Robbins W. E. , Bryce B. M.
Published: October 2006

The two major molting hormones of insects, alpha ecdysone and 20-hydroxyecdysone, were isolated in crystalline form from dry pinnae of the bracken fern,
Pteridium aquilinum
(L.) Kuhn. Three unidentified substances with molting hormone activity were also detected. Bracken is the first plant found to contain both of the major insect ecdysones, and it is the first known plant source of alpha ecdysone.