bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of Synthesis of the Cell Wall of
Staphylococcus aureus
by Cephalothin
Authors: Chang Te-Wen , Weinstein Louis
Published: October 2006

Cephalothin, 7-(thiophene-2-acetamido)-cephalosporanic acid, suppresses synthesis of the cell of
Staphylococcus aureus
. Exposure to this agent led to a reduction in the degree of incorporation of carbon-14-lysine into the mucopeptide of the cell wall material and to an accumulation of
N
-acetyl glucosamine in the cell. The intensity of the lesions was comparable to that produced by penicillin.
Inhibitory Postsynaptic Potentials in Grasshopper Muscle
Authors: Usherwood P. N. R. , Grundfest H.
Published: October 2006

Hyperpolarizing inhibitory postsynaptic potentials have been discovered in fibers of the "jumping" muscle of the grasshopper. These potentials attenuate the depolarizing excitatory postsynaptic responses. They are enhanced during depolarization of the muscle fiber with applied current and are diminished and then reversed during hyperpolarization. The electrogenesis appears to be caused by chloride-activation. Gamma-aminobutyric acid activates the inhibitory synaptic membrane and picrotoxin is an inactivator agent.
Salt Migration to the Northwest Body of Great Salt Lake, Utah
Authors: Adams Thomas C.
Published: October 2006

Interchange of saline lake water between the northwest body of Great Salt Lake, Utah, comprising about one-third of the lake area, and the main body of the lake, has been severely restricted by the completion of a railroad embankment across the lake in 1959. The northwest body has a relatively small volume of inflow and a somewhat greater rate of evaporation than the main body. As a result, there has been a net flow of saline water northward and accompanying deposition of a thick layer of salt over the bottom and shore of the northwest body. A unique set of hydrologic and physical-chemical influences are in action, and further important effects on the entire lake are expected.
Home Movies of Early Childhood: Correlative Developmental Data in the Psychoanalysis of Adults
Authors: Serota Herman M.
Published: October 2006

During the course of psychoanalytic practice, it has been possible to review with specific patients sequential films taken by their parents, beginning with the earliest weeks of infancy. The photographic evidence, combined with the patient's accompanying verbal associations, sheds additional light on evolving behavioral patterns such as affective expression, communication with others, and motility and its mastery, as well as early social interactions, and serves to correlate with reconstructions made from psychoanalytic data.
Molecular and Submolecular Localization of Two Isoantigens of Mouse Immunoglobulins
Authors: Mishell Robert I. , Fahey John L.
Published: October 2006

Three related classes of immunoglobulins (7
S
γ-, β
2A
-, and γ
1M
-globulin) in normal C3H and C57BL/6 mouse serums were isolated and examined for the isoantigens Iga-1 and Iga-2. The results indicate that the genetic locus determining the Iga-1 and Iga-2 antigens affects only a portion of the normal mouse immunoglobulin population (that is, 7
S
γ-globulin) and only the γ-specific part ("F" piece) of the 7
S
γ-globulin molecule.
Saltation and Stasis: a Model of Human Growth
Authors: Lampl M. , Veldhuis J. D. , Johnson M. L.
Published: October 2006

Human growth has been viewed as a continuous process characterized by changing velocity with age. Serial length measurements of normal infants were assessed weekly (
n
= 10), semiweekly (
n
= 18), and daily (
n
= 3) (19 females and 12 males) during their first 21 months. Data show that growth in length occurs by discontinuous, aperiodic saltatory spurts. These bursts were 0.5 to 2.5 centimeters in amplitude during intervals separated by no measurable growth (2 to 63 days duration). These data suggest that 90 to 95 percent of normal development during infancy is growth-free and length accretion is a distinctly saltatory process of incremental bursts punctuating background stasis.
Selectins: Interpreters of Cell-Specific Carbohydrate Information During Inflammation
Authors: Lasky Laurence A.
Published: October 2006

Although a bewildering array of cell surface carbohydrate structures have been described, the physiological relevance of any of these complex molecules has often eluded biologists. A family of cell surface glycoproteins, the "selectins," has a characteristic ability to use some of these carbohydrate structures in adhesive mechanisms that help localize leukocytes to regions of inflammation. This article will review the biology of these carbohydrate-binding adhesive proteins and discuss the potential for developing anti-inflammatory antagonists that could inhibit binding events that are selectin-mediated.
Post-Transcriptional Regulation of Early T Cell Development by T Cell Receptor Signals
Authors: Takahama Yousuke , Singer Alfred
Published: October 2006

During differentiation in the thymus, immature T cells progress through an ordered sequence of developmental stages that are best characterized by variable expression of the co-receptor molecules CD4 and CD8. Crosslinking of T cell receptor (TCR) molecules on precursor thymocytes was found to block their differentiation into CD4
+
CD8
+
cells by eliminating messenger RNA's encoding two families of developmentally important molecules: the co-receptor molecules CD4 and CD8 and the recombination activating genes 1 and 2. TCR-induced post-transcriptional regulation in early thymocytes was specific for selective messenger RNA's, required protein synthesis, and was itself developmentally regulated. These data identify a post-transcriptional mechanism that is influenced by TCR signals and that regulates early thymocyte development.
Polar Transport of Calcium in The Primary Root of
Zea mays
Authors: Evans Evan C.
Published: October 2006

Transport of calcium-45 in 20-mm root segments is basipetal and requires metabolic maintenance. Such transport reaches a maximum rate after immersion of the roots in tracer solution for approximately 12 hours and is still pronounced after 50 hours. Acropetal movement is slight, probably non-metabolic, and essentially constant. Amounts transported are linearly dependent on the absorbing area exposed to tracer solution.
High Pressure Solubility of Calcium Carbonate in Seawater
Authors: Pytkowicz Ricardo M. , Conners Donald N.
Published: October 2006

The saturation concentration of calcium carbonate, equilibrated with aragonitic oolites, is about 2.7 times larger after exposure to 1000 atmospheres than it is when saturation is achieved at 1 atmosphere. This suggests that deep ocean waters may be undersaturated with calcium carbonate, in which case the alkalinity of the oceans would increase as sinking calcareous organisms dissolve.
"Electrical Transmission" at an Excitatory Synapse in a Vertebrate Brain
Authors: Furshpan E. J.
Published: October 2006

A type of excitatory synaptic transmission which is novel for the vertebrate brain has been found in the medulla of the goldfish. Certain synaptic terminals (the club endings of Bartelmez) appear to stimulate the Mauthner neuron (M-cell) by means of the passive spread of their action currents across the synaptic membrane. After stimulating the ipsilateral eighth cranial nerve, an excitatory postsynaptic potential (EPSP) appears in the M-cell with a latency which is very brief (about 0.1 msec) and which probably represents a negligible synaptic delay. This response is attributed to the club endings: there were steep gradients of potential along the lateral dendrite of the M-cell during activity and the early EPSP was maximal in the distal part of the dendrite where the club endings predominate. Potential changes in the M-cell spread (passively) backwards into certain eighth-nerve fibers (probably club endings) indicating the presence of special low-resistance connections between them and the M-cell.
Binocular Depth Perception without Familiarity Cues
Authors: Julesz Bela
Published: October 2006

The reported phenomena were obtained through the use of special techniques. (i) All monocular depth and familiarity cues were removed from the stimuli (through the use of random-dot stereo patterns). (ii) The statistical and topological properties of the stimuli were precisely known (since they were generated according to a specific computer program). (iii) Convergence motions of the eye and proprioceptive cues were eliminated (through the use of tachistoscopic illumination). (iv) The time of presentation was under control (through erasure of the persistent afterimages). Under these conditions stereopsis could be studied in its purest form. It was shown that depth can be perceived in the absence of monocular depth and familiarity cues and of all binocular depth cues except for disparity. These findings have important implications for some existing theories of stereopsis and open up areas for further research. Some phenomena based on stereo erasure are reported here for the first time. It has been demonstrated that the perception of ambiguous depth organizations can be influenced, even subliminally, by a preceding unambiguous stimulus. Perhaps the most interesting result is the finding that the correspondence of objects and patterns in the two retinal projections can be established without actual recognition of the objects and patterns. This pattern matching is based on some relatively simple processes of finding connected clusters formed by adjacent points of similar brightness, and the processes seem to be amenable to rigorous analysis.
Human Erythrocyte Lactate Dehydrogenase: Four Genetically Determined Variants
Authors: Kraus Alfred P. , Neely Charles L.
Published: October 2006

Four variants of human erythrocyte lactate dehydrogenase (LDH) are described. One of these is similar to the one previously described by Boyer and is interpreted as a variant of LDH-B. The other three are thought to represent variants of LDH-A. Studies of families indicate that LDH-A and LDH-B are under separate genetic control and are inherited as autosomal co-dominants. Evidence is presented that the LDH-A locus is not closely linked to the loci for the ABH and Duffy blood group systems.
Isotopic Composition of Lead and Strontium from Ascension and Gough Islands
Authors: Gast Paul W. , Tilton G. R. , Hedge Carl
Published: October 2006

Isotopic composition of lead and strontium has been determined in a series of rock samples from two islands on the Mid-Atlantic Ridge. Both interand intra-island variations exist in the abundance of radiogenic isotopes of both elements. Lead from basalt of Ascension Island has a Pb
206
-Pb
204
ratio of 19.5, while the corresponding ratio at Gough Island is only 18.4. The Pb
208
-Pb
204
ratios from the two islands do not differ. Conversely, strontium from basalt of Ascension Island is less radiogenic than that from Gough Island basalts. The trachytes of both islands have lead and strontium that is more radiogenic than that found in the basalts. The inter-island differences indicate the existence of regional variations in the uranium-lead and rubidium-strontium ratios of the upper mantle source of these rocks and show that isotope compositions are a means for investigating chemical heterogeneities in the mantle.
Pollen Accumulation Rates: Estimates from Late-Glacial Sediment of Rogers Lake
Authors: Davis Margaret B. , Deevey Edward S.
Published: October 2006

Absolute pollen deposition in a Connecticut lake over a 4000-year interval has been estimated from pollen frequencies in a core of late-glacial sediment dated by radiocarbon techniques. The rate of total sediment accumulation as measured after burial was statistically constant at 0.036 centimeter per year, but the rate of deposition of pollen grains onto the sediment increased from 600 to 900 grains 14,000 years ago to 9000 per square centimeter per year 10,000 years ago. A major increase in the deposition of tree pollen occurred about 11,500 years ago, at the beginning of the spruce pollen zone. Presentation of data in conventional (percentage) form masks the magnitude of this change and distorts many of the changes in accumulation rates for individual types of pollen; moreover it magnifies statistical variation in the herb zone where all pollen is scarce.
Mononuclear and Polynuclear Chemistry of Rhenium (III): Its Pronounced Homophilicity
Authors: Cotton F. A. , Curtis N. F. , Harris C. B. , Johnson B. F. G. , Lippard S. J. , Mague J. T. , Robinson W. R. , Wood J. S.
Published: October 2006

Extensive chemical, spectrophotometric, and x-ray structural studies have shown that trivalent rhenium is strongly homophilic—that is, it tends to form bonds to other Re
III
atoms—and it forms at least three different series of [ReX
4
]
n
n-
complexes. The mononuclear, square complex, [ReBr
4
]
-
, adds two water molecules to give trans-[ReBr
4
(H
2
O)
2
]
-
. The binuclear complexes [Re
2
Cl
8
]
2-
and [Re
2
Br
8
]
2-
have strong Re-Re bonds, unsupported by halide bridges. The trinuclear species, [Re
3
X
12
]
3-
or Re
3
X
9
L
3
, contain the triangular Re
3
X
9
clusters. Use of ReCl
3
appears always to lead directly to products containing Re
3
Cl
9
; this unit exists in ReCl
3
itself and does not appear to be kinetically labile. The [Re
2
X
8
]
2-
ions are obtained by reduction of ReO
4
-
in aqueous HCl or HBr. Salts of [ReBr
4
(H
2
O)
2
]
-
can be obtained directly from solutions of ReBr
3
in HBr along with numerous other compounds, some containing trinuclear clusters.
Igneous Rocks of the East Pacific Rise
Authors: Engel A. E. J. , Engel Celeste G.
Published: October 2006

The apical parts of large volcanoes along the East Pacific Rise (islands and seamounts) are encrusted with rocks of the alkali volcanic suite (alkali basalt, andesine- and oligoclase-andesite, and trachyte). In contrast, the more submerged parts of the Rise are largely composed of a tholeiitic basalt which has low concentrations of K, P, U, Th, Pb, and Ti. This tholeiitic basalt is either the predominant or the only magma generated in the earth's mantle under oceanic ridges and rises. It is at least 1000-fold more abundant than the alkali suite, which is probably derived from tholeiitic basalt by magmatic differentiation in and immediately below the larger volcanoes.

Distinction of oceanic tholeiites from almost all continental tholeiites is possible on the simple basis of total potassium content, with the discontinuity at 0.3 to 0.5 percent K
2
O by weight. Oceanic tholeiites also are readily distinguished from some 19 out of 20 basalts of oceanic islands and seamount cappings by having less than 0.3 percent K
2
O by weight and more than 48 percent SiO
2
. Deep drilling into oceanic volcanoes should, however, core basalts transitional between the oceanic tholeiites and the presumed derivative alkali basalts.

The composition of the oceanic tholeiites suggests that the mantle under the East Pacific Rise contains less than 0.10 percent potassium oxide by weight; 0.1 part per million of uranium and 0.4 part of thorium; a potassium:rubidium ratio of about 1200 and a potassium: uranium ratio of about 10
4
.
Origin of High-Alumina Basalt, Andesite, and Dacite Magmas
Authors: Hamilton Warren
Published: October 2006

The typical volcanic rocks of most island arcs and eugeosynclines, and of some continental environments, are basalt, andesite, and dacite, of high alumina content. The high-alumina basalt differs from tholeiitic basalt primarily in having a greater content of the components of calcic plagioclase. Laboratory data indicate that in the upper mantle, below the level at which the basaltic component of mantle rock is transformed by pressure to eclogite or pyroxenite, the entire basaltic portion probably is melted within a narrow temperature range, but that above the level of that transformation plagioclase is melted selectively before pyroxene over a wide temperature range. The broad spectrum of high-alumina magmas may represent widely varying degrees of partial melting above the transformation level, whereas narrow-spectrum tholeiite magma may represent more complete melting beneath it.
Sea Water: Saturation with Apatites and Carbonates
Authors: Kramer James R.
Published: October 2006

Pacific Ocean water, on the average, appears to be slightly supersaturated at all temperatures with hydroxyapatite and carbonate fluorapatite. Water above 14°C is saturated with calcite, whereas water above 20°C is saturated with aragonite.
Graphitization of Organic Material in a Progressively Metamorphosed Precambrian Iron Formation
Authors: French Bevan M.
Published: October 2006

Organic matter in the sedimentary Biwabik iron formation in northern Minnesota shows a progressive increase in crystallinity where the formation is metamorphosed by the intrusive Duluth gabbro complex. X-ray diffraction of acid-insoluble residues shows that there is a complete range in crystallinity, from amorphous material in the unmetamorphosed sediments to completely crystalline graphite adjacent to the gabbro.
Anesthesia for the Bottlenose Dolphin,
Tursiops truncatus
Authors: Nagel E. L. , Morgane P. J. , McFarland W. L.
Published: October 2006

Anesthetics can be administered to the bottlenose dolphin,
Tursiops truncatus
by means of special ventilating equipment and intubation techniques. Nitrous oxide has been administered successfully on six occasions, and has produced definite signs of anesthesia. These developments open the possibility of performing major surgery in this species for the first time.
Paleozoic Mollusk:
Hyolithes
Authors: Marek Ladislav , Yochelson Ellis L.
Published: October 2006

An unusually well-preserved Ordovician fossil from Czechoslovakia shows that the enigmatic paired structures once thought to be outgrowths of the operculum of
Hyolithes
are really independent structures lying between the operculum and the aperture of the shell. The find seems to provide conclusive proof of the morphologic uniqueness of hyolithids.
Expression Directed from HIV Long Terminal Repeats in the Central Nervous System of Transgenic Mice
Authors: Corboy John R. , Buzy Jeanine M. , Zink M. Christine , Clements Janice E.
Published: October 2006

Infection with the human immunodeficiency virus (HIV) is frequently accompanied by the AIDS (acquired immunodeficiency syndrome) dementia complex. The role of specific HIV genetic elements in the pathogenesis of central nervous system (CNS) disease is not clear. Transgenic mice were constructed that contained the long terminal repeats (LTRs) of two CNS-derived strains and a T cell tropic strain of HIV-1. Only mice generated with CNS-derived LTRs directed expression in the CNS, particularly in neurons. Thus, some strains of HIV-1 have a selective advantage for gene expression in the brain, and neurons can supply the cellular factors necessary for their transcription.
Moth Sounds and the Insect-Catching Behavior of Bats
Authors: Dunning Dorothy C. , Roeder Kenneth D.
Published: October 2006

Captive bats trained to catch mealworms tossed in midair turned away from most of these targets when simultaneously confronted with a recorded train of the ultrasonic pulses generated by an Arctiid moth. When similarly exposed to the recorded echolocation pulses of another bat, presented at the same intensity as the "moth" sounds, they were not so affected.
Dominance and Diversity in Land Plant Communities
Authors: Whittaker R. H.
Published: October 2006

Most plant communities consist of several or many species which compete for light, water, and nutrients. Species in a given community may be ranked by their relative success in competition; productivity seems to be the best measure of their success or importance in the community. Curves of decreasing productivity connect the few most important species (the dominants) with a larger number of species of intermediate importance (whose number primarily determines the community's diversity or richness in species) and a smaller number of rare species. These curves are of varied forms and are believed to express different patterns of competition and niche differentiation in communities. It is probably true of plants, as of animals, that no two species in a stable community occupy the same niche. Evolution of niche differentiation makes possible the occurrence together of many plant species which are partial, rather than direct, competitors. Species tend to evolve also toward habitat differentiation, toward scattering of their centers of maximum population density in relation to environmental gradients, so that few species are competing with one another in their population centers. Evolution of both niche and habitat differentiation permits many species to exist together in communities as partial competitors, with distributions broadly and continuously overlapping, forming the landscape's many intergrading communities.
Entrainment of a Tidal Rhythm
Authors: Enright J. T.
Published: October 2006

The endogenous tidal rhythm of locomotor activity of the sandbeach isopod,
Excirolana chiltoni
, has been entrained in the laboratory by a device designed to simulate wave action on a beach. The essential component of the treatment appears to be mechanical stimulation by a water current.
Perception of Stroboscopic Movement: Evidence for Its Innate Basis
Authors: Rock Irvin , Tauber Edward S. , Heller Donald P.
Published: October 2006

Newborn guppies and newly hatched praying mantids were placed inside a stationary cylinder containing a columnar pattern such as is used to elicit the optokinetic reflex. By illuminating columns in sequence, the pattern was made to appear to rotate. All of the animals tested circled in the direction of apparent movement. As with humans, movement was only perceived at intermediate rates of flashing.
Amino Acids Released from the Cerebral Cortex in Relation to Its State of Activation
Authors: Jasper H. H. , Khan R. T. , Elliott K. A. C.
Published: October 2006

The rate of release of γ-aminobutyric acid from the perforated pial surface of the cerebral cortex in the cat showed systematic variations with the state of activation or "arousal" of the electrocorticogram. In animals subjected to midbrain coagulation and showing constant spindle patterns characteristic of sleep, the rate of release was three times greater (about 2 micrograms per hour per square centimeter) than in animals showing a largely "aroused" electrocorticogram, which had sections of the upper cervical cord or were neuraxially intact but had been given local anesthesia. The rate of release of glutamic acid was lower in the "sleeping" animals than in "aroused" animals, while no such differences were found for glutamine and aspartic acid. Such studies may lead to a better understanding of chemical mechanisms involved in the control of states of consciousness by the brain stem.
Nematodes: Biological Control in Rice Fields: Role of Hydrogen Sulfide
Authors: Rodriguez-Kabana Rodrigo , Jordan Jose Walfredo , Hollis John P.
Published: October 2006

In flooded rice fields a decline in total nematode populations began shortly after the onset of soil anaerobiosis and was correlated with a sustained increase in concentration of molecular hydrogen sulfide in the soil-water phase. Laboratory tests showed that hydrogen sulfide at concentrations found in flooded fields killed 100 percent of nematodes in 5 to 10 days. The effect of hydrogen sulfide and its pattern of occurrence in the soils of water-saturated rice fields suggest that this compound can be a significant factor in the etiology and control of certain plant diseases.
Electricity in Volcanic Clouds
Authors: Anderson Robert , Gathman Stuart , Hughes James , Björnsson Sveinbjörn , Jónasson Sigurgeir , Blanchard Duncan C. , Moore Charles B. , Survilas Henry J. , Vonnegut Bernard
Published: October 2006

In November of 1963 an oceanic volcano produced an island, Surtsey, just off the southern coast of Iceland. The volcanic crater was often flooded with sea water. Vigorous eruptions of steam and tephra were accompanied by an enhancement of the normal fine-weather potential gradient, and lightning was often observed. Measurements of atmospheric electricity and visual and photographic observations lead us to believe that the electrical activity is caused by the ejection from the volcano into the atmosphere of material carrying a large positive charge. The concentration of charge in the eruption plume as it issued from the orifice of the volcano is estimated to be of the order of 10
5
or 10
6
elementary charges per cubic centimeter.
Thyroid and Parathyroid Roles in Hypercalcemia: Evidence for a Thyrocalcitonin-Releasing Factor
Authors: Gittes Ruben F. , Irvin George L.
Published: October 2006

Extirpation of either the parathyroids or the thyroid in rats acutely impaired their ability to counteract hypercalcemia induced by exogenous parathormone. Thyroidectomy had the greater effect, and in rats subjected to both parathyroidectomy and thyroidectomy the calcium-lowering mechanism was not further impaired, which suggests that the parathyroids secrete a humoral factor that releases calcium-lowering thyrocalcitonin from the thyroid. This hypothesis reconciles previous conflicting reports.
Mus musculus
: Experimental Induction of Territory Formation
Authors: Anderson Paul K. , Hill James L.
Published: October 2006

In groups of house mice (
Mus musculus
) an experimentally imposed sequence of experience led to the establishment of male territories in suitably designed observation pens. This sequence consisted of familiarization with the area followed by combat with and social dominance over another male who was then removed, and a final step in which defeat on the home ground of a similarly experienced male was coupled with victory over the latter on familiar ground.
Actinomycin D Inhibition of Vitamin D Action
Authors: Zull J. Elwood , Czarnowska-Misztal E. , DeLuca Hector F.
Published: October 2006

Injection of actinomycin D into rats completely prevents both the rise in serum calcium normally induced by vitamin D and the increased transport of calcium by everted intestinal sacs. Injection of excess parathyroid hormone did not alter this result; this eliminates the possibility that the inhibition of vitamin action was due to blocked hormone synthesis. As a result of these findings, a hypothesis concerning the mechanism of action of vitamin D is presented.
Interferon-Like Virus-Inhibitor Induced in Human Leukocytes by Phytohemagglutinin
Authors: Wheelock E. Frederick
Published: October 2006

Phytohemagglutinin, an extract of the kidney bean,
Phaseolus vulgaris
, induces in human leukocyte cultures an inhibitor of the cytopathic effects of Sindbis virus. The physicochemical and biological properties of this virus-inhibitor are similar to those of interferon induced by Newcastle disease virus, except for an instability at
p
H 2 and 10 and at 56°C.
Osmotic Flow in a Rigid Porous Membrane
Authors: Mauro Alexander
Published: October 2006

The concept of an internal pressure gradient in a rigid porous membrane has been proposed as the basis for osmotic flow. The origin of the pressure in terms of the theory of the chemical potential implies also the existence of states of negative pressure, that is, tension. These states have been observed experimentally by means of a Hepp-type osmometer.
Color Adaptation of Edge-Detectors in the Human Visual System
Authors: McCollough Celeste
Published: October 2006

An aftereffect of color which depends on the orientation of lines in the test field may be obtained by presenting a horizontal grating of one color alternately with a vertical grating of a different color. Like the aftereffect of adaptation to chromatic fringes produced by prismatic spectacles, this aftereffect is visible in monochromatic light and fails to show interocular transfer. It is suggested that both effects are to be understood in terms of color adaptation of orientation-specific edge-detectors.
Mars: An Estimate of the Age of Its Surface
Authors: Baldwin Ralph B.
Published: October 2006

Intercomparisons of crater counts on Mars and the Moon suggest that the age of the visible Martian surface is approximately 340 to 680 million years.
Activation of Transcription Factors by Interferon-Alpha in a Cell-Free System
Authors: David Michael , Larner Andrew C.
Published: October 2006

The signal transduction mechanisms of interferons (IFNs) remain unclear partly because no effect of IFN has been reproducible in a cell-free system. IFN-α rapidly induces the transcription of a set of early response genes, and a multicomponent transcriptional activator, interferon stimulated gene factor 3 (ISGF3), is activated within minutes after binding of IFN-α to its receptor. A system was developed in which IFN-α activated ISGF3 in homogenates of HeLa cells. Subcellular fractionation revealed that incubation of a plasma membrane-enriched fraction with IFN-α was sufficient to activate the regulatory subcomponent of ISGF3.
Erythrocyte Membrane: Chemical Modification
Authors: Berg Howard C. , Diamond Jared M. , Marfey Peter S.
Published: October 2006

Erythrocytes treated with 1-fluoro-2,4-dinitrobenzene become permeable to Na
+
and K
+
, but not to small water-soluble nonelectrolytes or hemoglobin, and eventually lyse in isotonic buffer. Erythrocytes treated with 1,5-difluoro-2,4-dinitrobenzene become permeable to Na
+
and K
+
but do not lyse in buffer or in water, even after extraction with lipid solvents. The difluoro compound crosslinks the membrane and increases its strength. Both reagents appear to remove the positive fixed charge responsible for the cation impermeability of the normal cell.
Microorganisms from the Late Precambrian of Central Australia
Authors: Barghoorn Elso S. , Schopf J. William
Published: October 2006

An assemblage of structurally and organically well preserved microorganisms, interpreted as both green and blue-green algae, has been found in chert facies of the Bitter Springs limestone from the upper Precambrian of central Australia. This appears to be the earliest known occurrence of green algae in the fossil record. These organisms are among the oldest known multicellular and unicellular fossils exhibiting distinct histological preservation.
Lymphoma Growth in vivo: Electronic Discrimination between Tumor and Stroma Cells
Authors: Haughton G. , Haot J. , Révész L. , Klein G.
Published: October 2006

Moloney lymphoma cells are larger than normal cells of mouse spleen, lymph-node, and thymus. Use of electronic cell-size analysis in conjunction with specific immunocytolysis permits differential counting of host and tumor cells. Increase of lymphoma cells occurs first in spleen and then in lymph nodes; in thymus it occurs only during the terminal stages of tumor growth.
Bone: Formation by Autoinduction
Authors: Urist Marshall R.
Published: October 2006

Wandering histiocytes, foreign body giant cells, and inflammatory connective-tissue cells are stimulated by degradation products of dead matrix to grow in and repopulate the area of an implant of decalcified bone. Histiocytes are more numerous than any other cell form and may transfer collagenolytic activity to the substrate to cause dissolution of the matrix. The process is followed immediately by new-bone formation by autoinduction in which both the inductor cells and the induced cells are derived from ingrowing cells of the host bed. The inductor cell is a descendant of a wandering histiocyte; the induced cell is a fixed histiocyte or perivascular young connective-tissue cell. Differentiation of the osteoprogenitor cell is elicited by local alterations in cell metabolic cycles that are as yet uncharacterized.
Physiological Predetermination: Imbibition, Respiration, and Growth of Lima Bean Seeds
Authors: Woodstock L. W. , Pollock B. M.
Published: October 2006

Temperatures 15°C or lower during the first hour of imbibition immediately inhibited respiration in lima beans, with proportional inhibition of subsequent growth of seedlings. Correlations between initial respiration rates and growth rates of seedlings were found in different lots of seeds.
Neurosecretory Supply to the Epidermis of an Insect
Authors: Maddrell S. H. P.
Published: October 2006

Electron microscopy of the abdominal nerves of
Rhodnius
reveals neurosecretory axons which supply the abdominal epidermis. This suggests that the epidermal cells of insects are under more localized endocrine control than has previously been supposed.
Histamine Synthesis and Gastric Secretion after Portacaval Shunt
Authors: Fischer Josef E. , Snyder Solomon H.
Published: October 2006

In man there is an increased incidence of peptic ulcer after portacaval shunt. In the rat, 2 months after portacaval anastomosis, there is a generalized increase in the histamine content of the soft tissues, and the increase is most marked in the acid-secreting portion of the stomach. This appears to be secondary to increased activity of the histamine-synthesizing enzyme, histidine decarboxylase. A histidine decarboxylase inhibitor can prevent such hypersecretion of acid in the stomach of these animals.
Hemoglobin and Transferrin Electrophoresis and Relationships of Island Populations of
Anolis
Lizards
Authors: Gorman George C. , Dessauer Herbert C.
Published: October 2006

Electrophoretic differences in hemoglobins and transferrins serve to differentiate
Anolis
of the same species populating the Lesser Antilles. When based on protein analyses, identifications of individuals may be less equivocal than identification based on descriptions of skin color and markings. Protein differences among island populations appear to be associated with long periods of geographic isolation. Such evidence often confirms estimates of relationship derived from more traditional criteria and in some cases provides a basis for formulating new taxonomic conclusions.
Dendroctonus pseudotsugae
: A Hypothesis Regarding Its Primary Attractant
Authors: Heikkenen Herman J. , Hrutfiord Bjorn F.
Published: October 2006

The Douglas-fir beetle is attracted to α-pinene but repelled by β-pinene. Attacks on standing trees are related to the content of α- or β-pinene in the tree; this correlation suggests that volatile oils may be the stimuli initially attracting the insect to the Douglas fir.
Caterpillar Feeding on a Sundew Plant
Authors: Eisner Thomas , Shepherd Julian
Published: October 2006

The caterpillar of a plume moth (
Trichoptilus parvulus
) was found feeding on a sundew plant (
Drosera capillaries
) in Florida. The larva eats the stalked glands with their sticky secretion, the leaf blades, and even dead insects trapped by the plant.
Protein Conformations in the Plasma Membrane
Authors: Maddy A. H. , Malcolm B. R.
Published: October 2006

Infrared spectroscopy and optical rotatory dispersion have been used to test theories of structure of membrane protein. No evidence has been found to support the view that adjacent to the lipid there is a monolayer of protein in the β-conformation. The extracted protein appears to be a fairly typical globular protein with a low α-helical content.
Detection Thresholds as a Function of Interval Separation between Two Successive Targets
Authors: Schuckman Harold , Orbach J.
Published: October 2006

Detection thresholds for two successive targets varied systematically with the interval between the two pulses. At intervals of 10 to 30 milliseconds, and again at 80 to 200 milliseconds, the threshold was lowered as compared to that for a single target, while at a separation of 50 to 60 milliseconds, the threshold was raised.
A Search for Intergalactic Hydrogen in the Virgo Cluster
Authors: Goldstein Samuel J.
Published: October 2006

A fixed-horn antenna having a beam 10° by 10°, and a switched-load radiometer with traveling-wave-maser preamplifier were used to observe the 21-cm spectrum of the Virgo cluster of galaxies. An upper limit to the antenna temperature is 0.024°K relative to regions outside the cluster with filters whose width is 2 Mc/sec. If the excitation temperature of the intergalactic hydrogen is enough greater than the background continuum radiation so that absorption can be ignored, and if the velocity spectrum is that defined by the galaxies, the density of optically thin neutral hydrogen in the cluster does not exceed that outside of the cluster by an amount that gives 5.6 × 10
12
solar masses in the cluster.
Hormone-Induced Repression of a Peroxidase Isozyme in Plant Tissue
Authors: Ockerse R. , Siegel B. Z. , Galston A. W.
Published: October 2006

Young stem sections of dwarf peas (Progress No. 9) grown in light contain at least seven peroxidase isozymes separable by electrophoresis on starch gel. An eighth isozyme appears as the tissue elongates and ages, on or off the plant. The appearance of this isozyme in excised sections is repressed by application of the plant growth hormone, indole-3-acetic acid.
Fluorescent Tracer: Transport in Distance and Depth in Beach Sands
Authors: Schwartz Maurice L.
Published: October 2006

Foreshore tidal-cycle transport of sediment along a beach profile can be traced in distance and depth by the use of fluorescent pigments. Sediment cores are obtained from locations on the profile, dyed in horizontal segments, and returned to their original positions in the beach. Analyses of flood- and ebb-tide samples of sediment reveal the pattern of littoral zone sedimentation.
Acrylamide-Gel Electrophorograms by Mechanical Fractionation: Radioactive Adenovirus Proteins
Authors: Maizel Jacob V.
Published: October 2006

A mechanical fractionator was developed to produce electrophorograms by extrusion of polyacrylamide gels through a narrow orifice in a continuous, sequential stream. The system permits separation of uniform fractions free of zone distortion. An electrophorogram of radioactive type-2 adenovirus proteins so fractionated gave a pattern in excellent agreement with the pattern obtained by laborious manual sectioning and in agreement with the pattern obtained on a replicate gel stained with Coomassie brilliant blue R250. The adenovirus particle yielded about ten resolvable protein components in unequal amounts. Like picornaviruses, these icosahedral animal viruses have multiple protein components in the viral coat.
Polyribosome Disaggregation during Metaphase
Authors: Scharff Matthew D. , Robbins Elliott
Published: October 2006

Polyribosomes as examined by both sucrose-gradient analysis and electron microscopy disaggregate during metaphase in both normal HeLa cells and those arrested in metaphase by treatment with colchicine.
Activation Analysis of Ungulate Hair
Authors: Kennington Garth S. , Ching Clarence F. T.
Published: October 2006

Hair samples from the horse, elk, deer, moose, and antelope; subcutaneous tissue from the moose and antelope; and cast and living skin of the rattlesnake were activated by exposure to a neutron flux. The resulting products were studied by pulse-height analysis. Differences in type and proportion of trace elements appear to be consistent within the species studied.
Electron Microscopy: Two Major Synaptic Types on Spinal Motoneurons
Authors: Bodian David
Published: October 2006

Two major types of synaptic bulbs are defined on the motoneuron surface of the monkey, on the basis of content of agranular "synaptic" vesicles of two distinct kinds. Both types are present on dendritic as well as perikaryal surface. Because of the approximately equal numbers, the hypothesis that one type is excitatory and the other inhibitory naturally arises.
Mars: Upper Atmosphere
Authors: Gross S. H. , McGovern W. E. , Rasool S. I.
Published: October 2006

The thermal structure of the upper atmosphere of Mars has been theoretically investigated. The exospheric temperature, for a pure CO
2
model atmosphere, lies between 400° and 700°K. The origin of the Martian atmosphere is discussed in the light of these results.
Soil-Water Potential: Direct Measurement by a New Technique
Authors: Peck A. J. , Rabbidge R. M.
Published: October 2006

Current methods of measuring the potential of water in soil are inadequate. It is proposed to depress the reference free energy of water by a predetermined amount from the standard level of pure free water at atmospheric pressure by use of a solute. The specific free-energy difference of soil water from the depressed reference can be measured as a pressure.
Antibody Synthesis Initiated in vitro by Paired Explants of Spleen and Thymus
Authors: Saunders George C. , King Donald West
Published: October 2006

Primary in vitro synthesis of antibody has been achieved with a mouse spleen-thymus organ culture system 54 hours after it was incubated for 18 hours with coliphage R17.
Visceral Reflex Activity: Development in Postnatal Rabbit
Authors: Bradley William E. , Wright Francis S.
Published: October 2006

In postnatal rabbits there is progressive development of central regulation of the micturition reflex. During the first 1 to 2 days of postnatal life a coordinated sustained reflex may be obtained from the bladder which has been isolated from the central nervous system. Changes in reflex integration occur over the following 7 to 12 days, which result in a coordinated reflex dependent upon supraspinal influences.
Isopycnic Centrifugation for the Isolation of DNA Strands Coding for Ribosomal RNA
Authors: Davison Peter F.
Published: October 2006

Denatured DNA preparations from
Escherichia coli
were centrifuged to equilibrium in cesium chloride solutions. Hybridizing experiments with radioactively labeled ribosomal RNA showed that the DNA strands complementary to ribosomal RNA were distributed on the heavy side of the DNA band. By fractionating this band the DNA strands coding for ribosomal RNA may be enriched 5- to 20- fold.
Structure-Disrupting Ions: Detection of Qualitative Change in an Enzyme
Authors: Warren James C. , Peterson Dale M.
Published: October 2006

Preparations of erythrocyte glucose-6-phosphate dehydrogenase from normal individuals show similar degrees of inhibition by neutral salts. Preparations from Caucasian subjects with different hereditary deficiency syndromes differ from each other and from normal subjects, indicating a qualitative difference in these specific "deficient" enzymes. Sensitivity to neutral salts may be a means of detecting an amino acid substitution.
Polonium-210 Content of Human Tissues in Relation to Dietary Habit
Authors: Hill C. R.
Published: October 2006

Concentrations of polonium-210, a natural fallout nuclide, in human placentas collected in northern Canada ranged up to 27.8 picocuries per 100 grams, or 80 times the average United Kingdom value. High levels are related to the inclusion of reindeer or caribou meat in the diet, and a correlation exists between the concentrations of polonium-210 and cesium-137 in the placentas.
Root Pressure and Leaf Water Potential
Authors: Barrs H. D.
Published: October 2006

Measurements with thermocouple psychrometers were made of the water potentials of leaves from sunflower and pepper plants which had stood overnight in the dark in nutrient solutions containing carbowax. Similar measurements on the solutions showed that they had lower water potentials than the leaves, although the plants were measurably transpiring. Evidence that root pressure plays a part in this inversion of water potential gradient is presented.
Stimulation of the Proliferation of Cortical Neurons by Prenatal Treatment with Growth Hormone
Authors: Zamenhof Stephen , Mosley Josephine , Schuller Edith
Published: October 2006

Subcutaneous or intravenous injections daily of purified bovine pituitary growth hormone into pregnant rats from the 7th till the 20th day of pregnancy (total dose 36 mg) resulted in offspring with unchanged body weight but with significant increases in brain weight, brain DNA content, cortical cell density, and ratio of neurons to glia.
Clostridium botulinum
Type F: Isolation from Salmon from the Columbia River
Authors: Craig James M. , Pilcher K. S.
Published: October 2006

Clostridium botulinum
type F has been isolated from a salmon (
Clostridium botulinum
) taken from the Columbia River. Cultures of this type have been reported only twice before—once the toxin was identified and once the bacterium was isolated.
Cyclobutane-Type Pyrimidine Dimers in Polynucleotides
Authors: Setlow R. B.
Published: October 2006

The formation of cyclobutane-type dimers between adjacent pyrimidine residues in model polynucleotides or DNA may be represented by the general scheme

— PyPy′ —

hv

⇌ — P ̅y̅P̅y̅′̅ —

whereas the formation of all other known photoproducts follows the irreversible path

— Nucleotide

hv

→ product

Thus dimers are distinguished from other photoproducts by the fact that they can be monomerized, as well as formed, by ultraviolet irradiation. At large incident fluxes of photons the steady-state value of dimers depends on wavelength and
p
H, as well as on other characteristics of the surrounding medium. The number of dimers in an irradiated polynucleotide may be decreased by purely photochemical means, whereas this is not true for most other photoproducts, for which continued irradiation, irrespective of wavelength, always results in the formation of more photoproduct. The wavelength dependence of the steady-state for dimers is also reflected in the biological activity of irradiated transforming DNA. This experiment and the fact that photoreactivating enzyme plus visible light monomerizes dimers (and has not been demonstrated to have any effect on other photoproducts) are the strongest lines of experimental evidence that pyrimidine dimers of the cyclobutane type are biologically important lesions and can account for a large fraction of the effects of ultraviolet light on DNA in solution. Insofar as DNA is one of the more important biological structures, such dimers, when formed, account for a large part of the effects of ultraviolet radiation on biological systems.
Genetic Relations of Oceanic Basalts as Indicated by Lead Isotopes
Authors: Tatsumoto M.
Published: October 2006

The isotopic compositions of lead and the concentrations of lead, uranium, and thorium in samples of oceanic tholeiite and alkali suites are determined, and the genetic relations of the oceanic basalts are discussed. Lead of the oceanic tholeiites has a varying lead-206: lead-204 ratio between 17.8 and 18.8, while leads of the alkali basalt suites from Easter Island and Guadalupe Island are very radiogenic with lead-206: lead-204 ratios between 19.3 and 20.4. It is concluded that (i) the isotopic composition of lead in oceanic tholeiite suggests that the upper mantle source region of the tholeiite was differentiated from an original mantle material more than 1 billion years ago and that the upper mantle is not homogeneous at the present time, (ii) less than 20 million years was required for the crystal differentiation within the alkali suite from Easter Island, (iii) no crustal contamination was involved in the course of differentiation of rocks from Easter Island; however, some crustal contamination may have affected Guadalupe Island rocks, and (iv) alkali basalt may be produced from the tholeiite in the oceanic region by crystal differentiation. Alternatively the difference in the isotopic composition of lead in oceanic basalts may be produced by partial melting at different depths of a differentiated upper mantle.
Baffin Island Refugia Older than 54,000 Years
Authors: Löken Olav H.
Published: October 2006

Two radiocarbon determinations on marine shells from the east coast of Baffin Island give ages exceeding 50,000 years. These findings indicate the existence of unglaciated areas (refugia) between fiords occupied by outlet glaciers flowing toward Baffin Bay, from the central part of the Wisconsin ice sheet, over the Foxe Basin—Hudson Bay area.
DNA Synthesis and Differentiation in Embryonic Kidney Mesenchyme in vitro
Authors: Sobel Jael S.
Published: October 2006

Mitosis accompanies the differentiation of embryonic metanephrogenic mesenchyme in vitro. Inhibition of mitosis by 5-fluorodeoxyuridine, but not by x-rays, is associated with inhibition of differentiation. The difference may be due to the effect of 5-fluorodeoxyuridine on DNA synthesis.