bluuebunny/crossref_metadata_2025 huggingface dataset:
Bacterial Stromatolites: Origin of Laminations
Authors: Doemel William N. , Brock Thomas D.
Published: October 2006

Laminated mats composed of motile filamentous photosynthetic bacteria and nonmotile unicellular blue-green algae occur in a large number of Yellowstone hot springs at temperatures between 55° and 70°C. Field studies indicate that the bacteria are the predominant mat-forming component. Under low light intensities, mats composed exclusively of bacteria can be formed. The bacteria undergo a diurnal migration, moving on top of the algae during the night and becoming mixed again with the algae during the day as a result of algal growth. Thus, the laminations probably arise as a result of differential migration of the bacteria in daily response to reduced light intensities. This response to light is exactly opposite to that previously reported for filamentous stromatolite-forming, blue-green algae, but the net result is the same—formation of a laminated mat.
Banded Marker Chromosomes as Indicators of Intraspecies Cellular Contamination
Authors: Nelson-Rees Walter A. , Flandermeyer Robert R. , Hawthorne Paula K.
Published: October 2006

Chromosome banding revealed marker chromosomes characteristic of HeLa cells in cultures designated HEK, HEK/HRV, HBT-3, HBT-39B, MA160, and a strain of SA-4TxS-HuSa
1
. Other HeLa cell characteristics found were glucose-6-phosphate dehydrogenase type A mobility and lack of the Y chromosome. Conventional chromosome analysis and immunological and enzymatic techniques serve to monitor species specificity and racial origin of the donor. Chromosome banding, however, can monitor intralinear karyotype peculiarity and its evolution during long-term cultivation.
Methane Formation in Living Trees: A Microbial Origin
Authors: Zeikus J. G. , Ward J. C.
Published: October 2006

Visibly healthy hardwood trees located on poorly drained soils contained high pressures of methane. Heartwood from these trees was water-soaked, neutral to alkaline in
p
H, fetid in odor, and infested with a diverse population of obligately anaerobic bacteria. The bacterium responsible for methane formation in trees was isolated and characterized as a member of the genus
Methanobacterium
.
Earthquake Mechanics in the Central United States
Authors: Street Ronald L. , Herrmann Robert B. , Nuttli Otto W.
Published: October 2006

Focal mechanism solutions of earthquakes in the central United States suggest that local stress fields are important in determining the type and orientation of faulting. The implied stress system is considerably more complicated than that which would be produced by east-west trending compressive stresses, as previously suggested for this region.
Genetic Mapping of Ir Locus in Man: Linkage to Second Locus of HL-A
Authors: Blumenthal M. N. , Amos D. B. , Noreen H. , Mendell N. R. , Yunis E. J.
Published: October 2006

Fifty-seven members of a family that spanned three generations were studied for antigen E and ragweed skin sensitivity and HL-A antigens. There was significant association between the haplotype HL-A 2-12 and antigen E skin hypersensitivity (F = .22 to .26) in this family. The map order is first locus of HL-A, second locus of HL-A, and IrE. These determinants are considered to be part of the linkage group HL-1.
Inhibition of Tumor-Induced Lymphocyte Blastogenesis by a Factor or Factors Associated with Peripheral Leukocytes
Authors: Hattler B. G. , Soehnlen B.
Published: October 2006

A factor or factors concentrated on leukocytes of cancer patients depress the proliferative response of lymphocytes to stimulation with autologous tumor. Inhibitory activity with material eluted from cells resides in neither high nor lower molecular weight fractions but in a combination of the two. The finding suggests that in vitro inhibition of lymphocyte proliferation to autochthonous tumor occurs because of antigen-antibody complexes.
A Distinct Potassium Channel Polypeptide Encoded by the
Drosophila eag
Locus
Authors: Warmke Jeffrey , Drysdale Rachel , Ganetzky Barry
Published: October 2006

Many of the signaling properties of neurons and other electrically excitable cells are determined by a diverse family of potassium channels. A number of genes that encode potassium channel polypeptides have been cloned from various organisms on the basis of their sequence similarity to the
Drosophila
Shaker
(
Sh
) locus. As an alternative strategy, a molecular analysis of other
Drosophila
genes that were defined by mutations that perturb potassium channel function was undertaken. Sequence analysis of complementary DNA from the
ether à go-go
(
eag
) locus revealed that it encodes a structural component of potassium channels that is related to but is distinct from all identified potassium channel polypeptides.
Regulation of Phospholipase C-γ1 by Profilin and Tyrosine Phosphorylation
Authors: Goldschmidt-Clermont Pascal J. , Kim Jae Won , Machesky Laura M. , Rhee Sue Goo , Pollard Thomas D.
Published: October 2006

Epidermal growth factor and platelet-derived growth factor can stimulate the production of the second messenger inositol trisphosphate in responsive cells, but the biochemical pathway for these signaling events has been uncertain because the reactions have not been reconstituted with purified molecules in vitro. A reconstitution is described that requires not only the growth factor, its receptor with tyrosine kinase activity, and the soluble phospholipase C-γ1, but also the small soluble actin-binding protein profilin. Profilin binds to the substrate phosphatidylinositol 4,5-bisphosphate and inhibits its hydrolysis by unphosphorylated phospholipase C-γ1. Phosphorylation of phospholipase C-γ1 by the epidermal growth factor receptor tyrosine kinase overcomes the inhibitory effect of profilin and results in an effective activation of phospholipase C-γ1.
Silurian Trilete Spores and Spore Tetrads from Gotland: Their Implications for Land Plant Evolution
Authors: Gray Jane , Laufeld Sven , Boucot A. J.
Published: October 2006

Land-plant type spores occur in argillaceous limestones and platform graptolitic mudstones of Wenlock-Ludlow age in Sweden. Analysis of the stratal sequence demonstrates that occurrence of abundant spores is a function of depositional ecology, particularly water depth and shoreline proximity. This ecological analysis and the seeming absence of any correlation between the first appearances of abundant spores and megafossils of land-plant type raise the possibility that land plants evolved far earlier than the megafossil record suggests.
Water and Carbon in Rusty Lunar Rock 66095
Authors: Friedman Irving , Hardcastle Kenneth G. , Gleason Jim D.
Published: October 2006

Lunar rock 66095 contains a hydrated iron oxide and has an unusual amount of water for a lunar rock (140 to 750 parts per million), 90 percent of which is released below 690°C. The δof water released at these low temperatures varies from -75 to -140 per mil relative to standard mean ocean water (SMOW). The small amount of water released between 690° and 1300°C has a δ of about -175 ± 25 per mil SMOW. These δ values are not unusual for terrestrial water. The δ
18
O of water extracted from 110° to 400°C has a value of +5 ± 1 per mil SMOW, similar to the value for lunar silicates from rock 66095 and different from the value of -4 to -22 per mil found for samples of terrestrial rust including samples of rusted meteoritic iron. The amount of carbon varies from 11 to 59 parts per million with a δ
13
C from -20 to -30 per mil relative to Pee Dee belemnite. Only very small amounts of reduced species (such as hydrogen, carbon monoxide, and methane) were found, in contrast to the analyses of other lunar rocks. Although it is possible that most of the water in the iron oxide (goethite) may be terrestrial in origin or may have exchanged with terrestrial water during sample return and handling, evidence presented herein suggests that this did not happen and that some lunar water may have a δD that is indistinguishable from that of terrestrial water.
Stellar Motion Survey by Automation
Authors: Luyten Willem J.
Published: October 2006

The proper motion survey on plates taken with the 48-inch Schmidt telescope at Mount Palomar Observatory has now progressed to the point where some 250,000 new motions for faint stars have been measured, and 5,000 new white dwarfs and degenerate stars and 3,000 stars of low luminosity have been added.
Detection of a Gonadotropin in Rabbit Blastocyst before Implantation
Authors: Haour F. , Saxena B. B.
Published: October 2006

A gonadotropin similar to human chorionic gonadotropin or luteinizing hormone has been demonstrated in rabbit blastocyst prior to implantation. The gonadotropin has been detected by a radioreceptor assay for human chorionic gonadotropin with the use of the plasma membranes of bovine corpora lutea obtained during the first trimester of pregnancy. The concentrations of the human chorionic gonadotropin or luteinizing hormone per milliliter of blastocyst fluid were tenfold higher than those in the blood of pregnant rabbits on days 5 and 6 after mating.
Thermal Structure of the Lithosphere: A Petrologic Model
Authors: MacGregor Ian D. , Basu Asish R.
Published: October 2006

A preliminary evaluation of the thermal history of the upper mantle as determined by petrologic techniques indicates a general correspondence with theoretically derived models. The petrologic data supply direct information which may be used as an independent calibration of calculated models, serve as a base for evaluating the assumptions of the theoretical approach, and allow more careful selection of the variables describing mantle thermal properties and processes.

Like the theoretical counterpart, the petrological approach indicates that the lithosphere is dominated by two thermal regimes: first, there is a continental regime which cools at rates of the order of 10
9
years and represents the long-term cooling of the earth. Secondly, superimposed on the continental evolution is the thermal event associated with the formation of an oceanic basin, and which may be thought of as a 10
8
-year convective perturbation on the continental cycle. Of special interest is petrologic evidence for a sudden steepening of the thermal gradients across the lithosphere-asthenosphere boundary not seen in the theoretical models. The unexpected change of slope points to the need for a critical reevaluation of the thermal processes and properties extant in the asthenosphere. The potential of the petrologic contribution has yet to be fully realized. For a start, this article points to an important body of independent evidence critical to our understanding of the earth's thermal history.
A Mechanical Trigger for the Trot-Gallop Transition in Horses
Authors: Farley Claire T. , Taylor C. Richard
Published: October 2006

It is widely thought that animals switch gaits at speeds that minimize energetic cost. Horses naturally switched from a trot to a gallop at a speed where galloping required more energy than trotting, and thus, the gait transition actually increased the energetic cost of running. However, by galloping at this speed, the peak forces on the muscles, tendons, and bones, and presumably the chance of injury, are reduced. When the horses carried weights, they switched from a trot to a gallop at a lower speed but at the same critical level of force. These findings suggest that the trot-gallop transition is triggered when musculoskeletal forces reach a critical level.
Paleomagnetic Dating of Cave Paintings in Tito Bustillo Cave, Asturias, Spain
Authors: Creer Kenneth M. , Kopper John S.
Published: October 2006

Geomagnetic variations recorded in sediments deposited in Tito Bustillo Cave, Asturias, Spain, have been correlated with part of the geomagnetic record established for Lake Windermere, England. An age of between 11,200 and 11,600 years is suggested for a frieze of animals discovered in the cave, so that these polychrome paintings may be attributed to late Ice Age hunters (Magdalenian V-VI).
Neuroblastoma: Drug-Induced Differentiation Increases Proportion of Cytoplasmic RNA That Contains Polyadenylic Acid
Authors: Bondy Stephen C. , Prasad Kedar N. , Purdy Janet L.
Published: October 2006

The production of cytoplasmic RNA that contains polyadenylic acid is increased, relative to total cytoplasmic RNA, in a neuroblastoma clone, NBE
-
(A), after induction of differentiation by 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone, an inhibitor of adenosine 3′,5′-monophosphate phosphodiesterase. The amount of RNA that contains polyadenylic acid in cytoplasm may be greater in such differentiated neuroblastoma cells than in proliferating control cells.
Pancreatic Ribonuclease: Enzymic and Physiological Properties of a Cross-Linked Dimer
Authors: Bartholeyns Jacques , Moore Stanford
Published: October 2006

Monomeric ribonuclease A has very low activity toward typically double-stranded RNA's; the dimeric form of ribonuclease A obtained by cross linking the enzyme by dimethyl suberimidate has more than 78 times the activity of the monomer toward polyadenylate ⋅ polyuridylate and 440 times the activity of the monomer toward the double-stranded RNA of a virus from
Penicillium chrysogenum
. The half-life of the dimer in the bloodstream of the rat is 12 times that of the mononmer.
Central Trigeminal Structures and the Lateral Hypothalamic Syndrome in the Rat
Authors: Zeigler H. P. , Karten Harvey J.
Published: October 2006

Extrahypothalamic lesions of central trigeminal structures produce a syndrome of aphagia, adipsia, finickiness, and food spillage. The similarity of these effects to the lateral hypothalamic syndrome and the location of trigeminal structures within the diencephalon suggest that some components of the lateral hypothalamic syndrome are due to incidental damage to trigeminal fibers of passage.
Reproductive Patterns in the Deep-Sea Benthos
Authors: Rokop Frank J.
Published: October 2006

The reproductive condition of a variety of benthic invertebrates from the bathyal San Diego Trough was monitored periodically. In this physically seasonless, deep-sea environment most species reproduce throughout the year, and only a few display highly synchronous, annual reproductive cycles. These few are not typical deep-sea species; they are known from shallow water and belong to groups which are relatively unimportant in abyssal depths. Of the 11 species examined, 3 bivalves, 2 ophiuroids, 2 isopods, 1 amphipod, and 1 polychaete breed year-round, and 1 brachiopod and 1 scaphopod spawn seasonally.
Size and Scaling in Human Evolution
Authors: Pilbeam David , Gould Stephen Jay
Published: October 2006

Our general conclusion is simply stated: many lineages display phyletic size increase; allometric changes almost always accompany increase in body size. We cannot judge adaptation until we separate such changes into those required by increasing size and those serving as special adaptations to changing environments.

In our view, the three australopithecines are, in a number of features, scaled variants of the "same" animal. In these characters,
A. africanus
is no more "advanced" than the larger, more robust forms. The one early hominid to show a significant departure from this adaptive pattern toward later hominids—cranially, dentally, and postcranially—is
H. habilis
from East Africa. The australopithecines, one of which was probably a precursor of the
Homo
lineage, were apparently a successful group of basically vegetarian hominids, more advanced behaviorally than apes (
87
), but not hunter-gatherers.

The fossil hominids of Africa fall into two major groupings. One probable lineage, the australopithecines, apparently became extinct without issue; the other evolved to modern man. Both groups displayed steady increase in body size. We consider quantitatively two key characters of the hominid skull: cranial capacity and cheek tooth size. The variables are allometrically related to body size in both lineages. In australopithecines, the manner of relative growth neatly meets the predictions for functional equivalence over a wide range of sizes (negative allometry of cranial capacity with a slope against body weight of 0.2 to 0.4 and positive allometry of postcanine area with a slope near 0.75). In the
A. africanus
to
H. sapiens
lineage, cranial capacity increases with positive allometry (slope 1.73) while cheek teeth decrease absolutely (slope — 0.725). Clearly, these are special adaptations unrelated to the physical requirements of increasing body size. We examined qualitatively other features, which also seem to vary allometrically. Of course, many characters should be studied quantitatively, but we think that the scheme outlined here should be treated as the null hypothesis to be disproved.
Transcontinental Baselines and the Rotation of the Earth Measured by Radio Interferometry
Authors: Shapiro I. I. , Robertson D. S. , Knight C. A. , Counselman C. C. , Rogers A. E. E. , Hinteregger H. F. , Lippincott S. , Whitney A. R. , Clark T. A. , Niell A. E. , Spitzmesser D. J.
Published: October 2006

Nine separate very-long-baseline interferometry (VLBI) experiments, carried out in 1972 and 1973 with radio telescopes 3900 kilometers apart, yielded values for the baseline length with a root-mean-square deviation about the mean of less than 20 centimeters. The corresponding fractional spread is about five parts in 108. Changes in universal time and in polar motion were also determined accurately from these data; the root-mean-square scatter of these results with respect to those based on optical methods were 2.9 milliseconds and 1.3 meters, respectively. Solid-earth tides were apparently detected, but no useful estimate of their amplitude was extracted.
Arginine Vasotocin: Effects on Development of Reproductive Organs
Authors: Vaughan Mary K. , Vaughan George M. , Klein David C.
Published: October 2006

Immature 25-day-old mice were injected daily with 1 microgram of arginine vasotocin for 3 or 4 days and killed 24 hours after the last injection. The ovaries were 30 percent smaller in treated females than in controls. The ventral prostates and accessory organs (seminal vesicles and coagulating glands) were less than half the size of these structures in control males. Similar results were observed when 15-day-old mice were given similar injections and killed 2 weeks after the last injection; furthermore, testis weights were 28 percent smaller than those of controls. It is speculated that arginine vasotocin, which has been found in mammalian pineal glands, might mediate effects of the pineal gland on normal sexual development.
Electron Diffraction of Frozen, Hydrated Protein Crystals
Authors: Taylor Kenneth A. , Glaeser Robert M.
Published: October 2006

High-resolution electron diffraction patterns have been obtained from frozen, hydrated catalase crystals to demonstrate the feasibility of using a frozen-specimen hydration technique. The use of frozen specimens to maintain the hydration of complex biological structures has certain advantages over previously developed liquid hydration techniques.
Radioimmunoassay for Human Procollagen
Authors: Taubman Mark B. , Goldberg Burton , Sherr Charles J.
Published: October 2006

Rabbit antiserums were produced against the procollagen molecule secreted into the medium of cultured human skin fibroblasts. The isolated antigenic, amino terminal portion of the procollagen molecule was purified, labeled with iodine-125, and used in a radioimmunoassay which detected nanogram quantities of the same antigen. With the assay, immunologically identical molecules were detected in the culture medium of different strains of human fibroblasts and in normal human serums. Serums from human cord blood contained a 12-fold higher concentration of the antigen than serums from adults, while serums from other vertebrates gave reactions to incomplete cross-reactivity or non-reactivity.
Adenosine 3′,5′-Monophosphate Content in Rat Caudate Nucleus: Demonstration of Dopaminergic and Adrenergic Receptors
Authors: Forn Javier , Krueger Bruce K. , Greengard Paul
Published: October 2006

Dopamine, apomorphine, isoproterenol, and norepinephrine each increased the concentration of adenosine 3′,5′-monophosphate in slices of rat caudate nucleus. The concentrations of dopamine, apomorphine, isoproterenol, and norepinephrine causing half-maximal increases were 60, 150, 0.03, and 30 micromoles per liter, respectively. The effect of dopamine was blocked by fluphenazine, a dopamine receptor antagonist, but not by propranolol, a β-adrenergic receptor antagonist. Conversely, the effect of isoproterenol was blocked by propranolol but not by fluphenazine. The results suggest that in rat caudate nucleus there are two distinct catecholamine receptors capable of causing increased concentrations of adenosine 3′,5′-monophosphate, one having the characteristics of a dopamine receptor, and the other having the characteristics of a β-adrenergic receptor.
Beginnings of Fruit Growing in the Old World
Authors: Zohary Daniel , Spiegel-Roy Pinhas
Published: October 2006

The article reviews the available information on the start of fruit tree cultivation in the Old World. On the basis of (i) evaluation of the available archeological remains and (ii) examination of the wild relatives of the cultivated crops, it was concluded that olive, grape, date, and fig were the first important horticultural additions to the Mediterranean grain agriculture. They were most likely domesticated in the Near East in protohistoric time (fourth and third millennia B.C.) and they emerge as important food elements in the early Bronze Age.

Domestication of all four fruit trees was based on a shift from sexual reproduction (in the wild) to vegetative propagation of clones (under domestication). Olive, grape, date, and fig can be vegetatively propagated by simple techniques (cuttings, basal knobs, suckers) and were thus preadapted for domestication early in the development of agriculture.

The shift to clonal propagation placed serious limitations on selection and on fruit set under cultivation. We have examined the consequences of this shift in terms of the genetic makeup of the cultivars and traced the various countermeasures that evolved to ensure fruit set.

Finally, it was pointed out that in each of these classic fruit trees we are confronted with a variable complex of genuinely wild types, secondary weedy derivatives and feral plants, and groups of the domesticated clones, which are all interfertile and interconnected by occasional hybridization. It was concluded that introgression from the diversified wild gene pool facilitated the rapid buildup of variation in the domesticated crops.
Global Increase in Quaternary Explosive Volcanism
Authors: Kennett James P. , Thunell Robert C.
Published: October 2006

The worldwide distribution of volcanic ash has been determined from 320 deep-sea sections drilled during the Deep Sea Drilling Project. The ash distribution in the deep-sea sections, which span the last 20 million years, indicates that there has been a much higher rate of explosive volcanism from both island arc and hot spot volcanoes during the last 2 million years. This episode, and perhaps another in the Middle Miocene correlates with previously reported widespread synchronism in increased volcanicity in certain oceanic islands. Increased Quaternary volcanism coincides approximately with that episode of the Cenozoic marked by major and rapidly fluctuating climatic change.
Sexual Selection in a Wild Population of the Butterfly
Danaus chrysippus
L.
Authors: Smith David A. S.
Published: October 2006

Danaus chrysippus
has two common forms,
chrysippus
and
dorippus
, in east Africa. Form
chrysippus
males have a mating advantage lasting 3 to 4 months, which is lost as their frequency increases. Female
dorippus
are normally superior to female
chrysippus
in sexual vigor. Sexual selection favoring different morphs in each sex contributes to the maintenance of the polymorphism.
Photoperiodism and Effects of Indoleamines in a Unicellular Alga,
Gonyaulax polyedra
Authors: Balzer Ivonne , Hardeland Rüdiger
Published: October 2006

Mediation of photoperiodic effects by indoleamines, especially melatonin, is known in higher vertebrates. A similar mechanism may occur in a unicellular alga, the dinoflagellate
Gonyaulax polyedra
. This organism entered the dormant stage of a cyst upon short-day treatment at lowered temperatures. Interruption of darkness by 2 hours of light prevented cyst formation, even when the overall duration of light was the same as in cyst-inducing short days. When given in a noninducing photoperiod, melatonin and an analog, 5-methoxytryptamine, substances that had previously been shown to occur in
Gonyaulax
, provoked cyst formation. Methoxylated indoleamines may play a role as mediators of darkness in this unicellular, in a similar way as in vertebrates, suggesting a common biochemical basis of photoperiodism.
Polycyclic Aromatic Hydrocarbons in Soils and Recent Sediments
Authors: Blumer M. , Youngblood W. W.
Published: October 2006

Soils and recent marine sediments contain a complex polycyclic aromatic hydrocarbon assemblage. There is a high degree of similarity in the molecular weight distribution of the many series of alkyl homologs of these aromatic hydrocarbons, and this distribution varies little over a wide range of depositional environments. The evidence suggests that these hydrocarbons are formed in natural fires, are dispersed and mixed by air transport, and are eventually deposited into surface sediments. The analytical, geochemical, and environmental implications of these findings are discussed.
Geomagnetic Variations in the Eastern United States: Evidence for a Highly Conducting Lower Crust?
Authors: Edwards R. N. , Greenhouse J. P.
Published: October 2006

Temporal geomagnetic variations, recorded at ten stations across the east-central United States, are interpreted in terms of the electrical conductivity structure of the earth beneath this region. The results are surprising and suggest that the lower crust is highly conducting, having distinct lateral variations in conductivity beneath the Appalachian Mountains.
Manganese Encrustation of Zygospores of a
Chlamydomonas
(Chlorophyta: Volvocales)
Authors: Schulz-Baldes M. , Lewin Ralph A.
Published: October 2006

In media containing normal trace-element supplements, but not in manganese-deficient media, zygospores of a new species of
Chlamydomonas
(isolated from soil) become encrusted with a dark brown mineral coating. Staining with benzidine indicates that the encrustation is rich in manganese. This has been confirmed by x-ray analysis in combination with a scanning electron microscope.
An Intercontinental Array—A Next-Generation Radio Telescope
Authors: Swenson G. W. , Kellermann K. I.
Published: October 2006

It is difficult to estimate accurately the cost of constructing a large scientific instrument that involves many techniques. On the other hand, most of the component parts of the VLBA consist of antennas and electronic systems that already exist or are being fabricated. The kind of 25-m antennas being constructed for the VLA will cost about $900,000 each and will work at wavelengths as short as 1 cm. A multifrequency radiometer, hydrogen maser frequency standard, small control computer, control building, and wide-band instrumentation recorder bring the cost to about $1.5 million per element, or $15 million for a ten-element array using tape recorders. A multistation playback facility, with ten recorders and enough correlators to handle all interferometer pairs simultaneously, together with the necessary computers to control the processor and reduce the data, may add $5 million. The total cost is thus about $20 million at current prices, including an adequate supply of magnetic tape. This is comparable to the cost of existing large radio telescopes and arrays.

An array that used a geostationary communication satellite to transmit the data to a real-time correlator would cost $30 million to $50 million more, but this is still within the price range of other space astronomy projects.

It is thus feasible to construct at reasonable cost an intercontinental very long baseline array which has sub-milliarcsecond resolution. This would complement the Very Large Array now being constructed, which is much more sensitive to objects of low surface brightness. This next step would permit the study of the universe with unprecedented angular resolution.
Induction of Inflammatory Arthropathy Resembling Rheumatoid Arthritis in Mice Transgenic for HTLV-I
Authors: Iwakura Yoichiro , Tosu Mariko , Yoshida Emi , Takiguchi Masafumi , Sato Kazuto , Kitajima Isao , Nishioka Kusuki , Yamamoto Kazuhiko , Takeda Toshio , Hatanaka Masakazu , Yamamoto Hiroaki , Sekiguchi Toyozo
Published: October 2006

Human T cell leukemia virus type-I (HTLV-I) is the etiologic agent of adult T cell leukemia and has also been suggested to be involved in other diseases such as chronic arthritis or myelopathy. To elucidate pathological roles of the virus in disease, transgenic mice were produced that carry the HTLV-I genome. At 2 to 3 months of age, many of the mice developed chronic arthritis resembling rheumatoid arthritis. Synovial and periarticular inflammation with articular erosion caused by invasion of granulation tissues were marked. These observations suggest a possibility that HTLV-I is one of the etiologic agents of chronic arthritis in humans.
Biogeography of the Megazoo
Authors: Sullivan Arthur L. , Shaffer Mark L.
Published: October 2006

A system of primary wildland reserves may be required to ensure a diversity of plant and animal species in the future. A strategy for locating such reserves involves considerations of their location, number, size, and linkage. The equilibrium theory of island biogeography is a useful analytical tool for predicting future biogeographies according to the dynamics of present plant and animal distributions. Existing reserves in the United States are inadequate in size and number and are clumped in one geographic region. In a planned network there might be several levels of reserves, starting with first- and second-order watersheds of large enough size to support a stable population of large carnivores. Reserves should be distributed so that they include a maximum of the world's biological diversity. Lower-order reserves might serve as stepping-stones among which a supply of species might move as a kind of distributed storage and reintroduce themselves when local instabilities occur. This would maintain a high immigration rate to balance an extinction rate which can only increase as human settlements expand.
Precipitation: Its Acidic Nature
Authors: Frohliger John O. , Kane Robert
Published: October 2006

A comparison of the free hydrogen ion concentration and the total hydrogen ion concentration of rain samples shows that rain is a weak acid. The weak acid nature of rain casts doubt on the concepts that the acidity of rain is increasing and that these increases are due to strong acids such as sulfuric acid.
Nitrogen Dioxide in the Stratosphere and Troposphere Measured by Ground-Based Absorption Spectroscopy
Authors: Noxon J. F.
Published: October 2006

The NO
2
abundance in the stratosphere has been determined from ground-based spectra of the rising and setting sun and moon and of the twilight sky near 4500 angstroms. The spectra were taken at the Fritz Peak Observatory, at an altitude of 3 kilometers in the Colorado mountains. Separation of the stratospheric contribution requires observations at a relatively unpolluted site; direct measurement of the tropospheric absorption in the Colorado mountains often yields an upper limit on the tropospheric mixing ratio of 0.1 part per billion. The stratospheric NO
2
abundance is two to three times greater at night than during the day and increases significantly during the course of a sunlit day; these changes are related to photolytic decomposition of NO
2
and N
2
O
5
in the daytime stratosphere. Absorption by NO
3
was sought but not found; the results set an upper limit of 2 percent on the nighttime abundance ratio of NO
3
to NO
2
in the stratosphere.
Flash Hydrogenation of a Bituminous Coal
Authors: Squires Arthur M. , Graff Robert A. , Dobner Samuel
Published: October 2006

Flash heating of Illinois coal (to 700°C in 1 second) in flowing hydrogen at 100 atmospheres, limiting the vapor residence time at 700°C to 3 seconds, converts 14 percent of the coal's carbon to methane, 7 percent to ethane, and 10 percent to benzene, toluene, and xylenes. The remainder is coke; the carbon balance shows that heavy tar, if any exists, is less than 3 percent.
Autoassociation and Novelty Detection by Neuromechanics
Authors: Daunicht Wolfgang J.
Published: October 2006

Many biomechanical systems contain ball joints with several elastic actuators (muscles) obliquely attached to the links. The problem of calculating the optimum actuator commands to achieve a desired link orientation is a difficult one for any control system; however, the elasticity of the actuators may be part of the solution. Mechanoreceptors such as those found in muscles and tendons are capable of performing operations that can be regarded as autoassociation and novelty detection, respectively, by minimization of potential energy. The information provided by such sensors may then be exploited for optimization of muscle coordination.
Presynaptic Electrical Coupling in
Aplysia
: Effects on Postsynaptic Chemical Transmission
Authors: Waziri Rafig
Published: October 2006

The large cholinergic interneuron L
10
in the abdominal ganglion of
Aplysia
mediates both chemical and electrical synaptic transmission. The amplitudes of postsynaptic potentials produced by different branches of L
10
are differentially affected when the electrically coupled neuron L
20
is depolarized or hyperpolarized. Polarizations applied to L
20
are transmitted to L
10
branches by the "presynaptic" electrical synapse. Depolarization increases the amplitude of the postsynaptic potential, while hyperpolarization has the opposite effect. The differential effects occur because current supplied through the electrical synapse undergoes more electrotonic decrement for the distant branches than for branches closer to the electrical synapse. These findings indicate that the presynaptic electrically coupled neuron may have an integrative role in the modulation of chemical synaptic efficacy mediated by L
10
.
The Medial Temporal Lobe Memory System
Authors: Squire Larry R. , Zola-Morgan Stuart
Published: October 2006

Studies of human amnesia and studies of an animal model of human amnesia in the monkey have identified the anatomical components of the brain system for memory in the medial temporal lobe and have illuminated its function. This neural system consists of the hippocampus and adjacent, anatomically related cortex, including entorhinal, perirhinal, and parahippocampal cortices. These structures, presumably by virtue of their widespread and reciprocal connections with neocortex, are essential for establishing long-term memory for facts and events (declarative memory). The medial temporal lobe memory system is needed to bind together the distributed storage sites in neocortex that represent a whole memory. However, the role of this system is only temporary. As time passes after learning, memory stored in neocortex gradually becomes independent of medial temporal lobe structures.
A Nonconservative Serine to Cysteine Mutation in the Sulfate-Binding Protein, a Transport Receptor
Authors: He Jing J. , Quiocho Florante A.
Published: October 2006

Serine 130 is one of seven residues that form a total of seven hydrogen bonds with the sulfate completely sequestered deep in the cleft between the two lobes of the bilobate sulfate-binding protein from
Salmonella typhimurium
. This residue has been replaced with Cys, Ala, and Gly by site-directed mutagenesis in an
Escherichia coli
expression system. Replacement with the isosteric Cys caused a 3200-fold decrease in the sulfate-binding activity relative to the wild-type activity, whereas replacement with Ala and Gly resulted in only 100- and 15-fold decreases, respectively. The effect of the Cys substitution is attributed largely to steric effect, whereas the Gly substitution more nearly reflects the loss of one hydrogen bond to the bound sulfate with a strength of only 1.6 kilocalories per mole.
Triassic Pollen Date Moroccan High Atlas and the Incipient Rifting of Pangea as Middle Carnian
Authors: Cousminer Harold L. , Manspeizer Warren
Published: October 2006

Palynomorphs from the High Atlas Mountains south of Marrakech define the
Minutosaccus-Patinasporites
Concurrent Range Zone, which is time-stratigraphically equivalent to the Swiss and English middle Keuper, type Carnian of Austria, and North American Triassic beds in Virginia, North Carolina, Pennsylvania, New Jersey, Texas, New Mexico, and Arizona, thus dating an early episode of continental rifting between Africa and North America.
Historical Dates for Neolithic Sites of Southeast Europe
Authors: Ferguson C. Wesley , Gimbutas Marija , Suess Hans E.
Published: October 2006

Direct comparison of the radiocarbon contents of charcoal samples with those of bristlecone pine wood samples dated by tree rings shows that a full-fledged Neolithic with pottery and all the domesticated animals, except the horse, was present in southeast Europe as early as the 65th century B.C. The chronologies for the stratigraphic sequences of the settlements of Achilleion and Anza, based on a total of 37 La Jolla radiocarbon measurements, cover almost 1000 years.
Palaeosclerotium
, a Pennsylvanian Age Fungus Combining Features of Modern Ascomycetes and Basidiomycetes
Authors: Dennis Robert L.
Published: October 2006

Fruiting bodies described previously as sclerotia of
Palaeosclerotium pusillum
are cleistothecium-like, enclosed structures, containing spores within an ascus. The cleistothecia are composed of hyphae having dolipore-like septa and are attached to vegetative hyphae having clamp connections. The unique combination of ascomycete-like reproductive bodies and basidiomycete-like hyphae present in this Pennsylvanian fungus suggests that there already existed, during the Middle Pennsylvanian period, a group of fungi intermediate between the Ascomycetes and Basidiomycetes.
Metamict Mineral Alteration: An Implication for Radioactive Waste Disposal
Authors: Ewing Rodney C.
Published: October 2006

Pervasive alteration is a common feature of metamict minerals. Previous studies of metamict niobium-tantalum-titanium oxides and electron microprobe analyses of altered areas in metamict yttrialite document the leaching of uranium, thorium, and rare earth elements. These data suggest that glasses may not provide a stable medium for radioactive waste disposal.
Electronic Data Publishing and GenBank
Authors: Cinkosky Michael J. , Fickett James W. , Gilna Paul , Burks Christian
Published: October 2006

GenBank, the national repository for nucleotide sequence data, has implemented a new model of scientific data management, which we term electronic data publishing. In traditional publishing, both scientific conclusions and supporting data are communicated via the printed page, and in electronic journal publishing, both types of information are communicated via electronic media. In electronic data publishing, by contrast, conclusions are published in a journal while data are published via a network-accessible, electronic database.
Cell Cycle Dependence of Laminar Determination in Developing Neocortex
Authors: McConnell Susan K. , Kaznowski Christine E.
Published: October 2006

The neocortex is patterned in layers of neurons that are generated in an orderly sequence during development. This correlation between cell birthday and laminar fate prompted an examination of how neuronal phenotypes are determined in the developing cortex. At various times after labeling with [
3
H]thymidine, embryonic progenitor cells were transplanted into older host brains. The laminar fate of transplanted neurons correlates with the position of their progenitors in the cell cycle at the time of transplantation. Daughters of cells transplanted in S-phase migrate to layer 2/3, as do host neurons. Progenitors transplanted later in the cell cycle, however, produce daughters that are committed to their normal, deep-layer fates. Thus, environmental factors are important determinants of laminar fate, but embryonic progenitors undergo cyclical changes in their ability to respond to such cues.
Sebertia acuminata
: A Hyperaccumulator of Nickel from New Caledonia
Authors: Jaffré T. , Brooks R. R. , Lee J. , Reeves R. D.
Published: October 2006

Sebertia acuminata
(Sapotaceae) from New Caledonia has been shown to be a hyperaccumulator of nickel. The nickel content of the latex (25.74 percent on a dry weight basis) is easily the highest nickel concentration ever found in living material. The nickel is in the form of a low-molecular-weight, water-soluble organic complex.
Rhizoid Differentiation in Fern Spores: Experimental Manipulation
Authors: Miller John H. , Greany Robin H.
Published: October 2006

Germination in spores of the fern
Onoclea sensibilis
is initiated by an asymmetric division that partitions the spore into two cells of unequal size. The unequal daughter cells differentiate immediately into distinct types. When spores are germinated on the surface of solutions of methanol, the initial division is symmetrical, and the daughter cells from this equal division develop into the same type of cell. The differentiation of a rhizoid from the smaller cell in untreated spores is suppressed by methanol treatment.
Yellowstone: Seismic Evidence for a Chemical Mantle Plume
Authors: Hadley David M. , Stewart Gordon S. , Ebel John E.
Published: October 2006

Arrivals of P waves from a recent event at the Nevada Test Site, recorded at a distance of 15.3°, passed beneath the Yellowstone caldera at depths of 200 and 400 kilometers. The travel time anomalies are modeled by a vertical cylindrical structure with a high-velocity core and a low-velocity collar as compared with the more normal mantle. The velocity structure and vertical extent of this feature are consistent with a chemical mantle plume beneath the Yellowstone caldera.
Human Breast Cancer: Biologically Active Estrogen Receptor in the Absence of Estrogen?
Authors: Zava David T. , Chamness Gary C. , Horwitz Kathryn B. , McGuire William L.
Published: October 2006

The human breast cancer cell line MCF-7 does not require estrogen for growth, but paradoxically its growth is inhibited by antiestrogens. Our results show that, unlike normal target cells, MCF-7 cells carry most of their estrogen receptors in their nuclei even when these receptors are not charged with estrogens. The receptors for androgen and for progesterone, on the other hand, are localized in the cytoplasm as usual. Therefore, it is possible that the growth of these abnormal cells is stimulated by estrogen receptor in spite of the absence of the hormone and that the binding of antiestrogen molecules antagonize this stimulation.
Chlamydiae (with Phages), Mycoplasmas, and Rickettsiae in Chesapeake Bay Bivalves
Authors: Harshbarger John C. , Chang Sing Chen , Otto Sara V.
Published: October 2006

Intracytoplasmic chlamydia-like organisms, some with phages, rickettsia-like organisms, and mycoplasma-like organisms have been found in clams and oysters from the Chesapeake Bay area by electron microscopy. None of these organisms have been previously detected in mollusks, nor have phages been previously observed in
Chlamydia
sp.
Energy Research: Accelerator Builders Eager to Aid Fusion Work
Authors: Metz William D.
Published: October 2006

Useful fusion energy may be generated by means of heavy ion accelerator driven implosions if the constraints dictated by the physics and economics of thermonuclear targets and reactors can be satisfied.
X-Ray Structure of the GCN4 Leucine Zipper, a Two-Stranded, Parallel Coiled Coil
Authors: O'Shea Erin K. , Klemm Juli D. , Kim Peter S. , Alber Tom
Published: October 2006

The x-ray crystal structure of a peptide corresponding to the leucine zipper of the yeast transcriptional activator GCN4 has been determined at 1.8 angstrom resolution. The peptide forms a parallel, two-stranded coiled coil of α helices packed as in the "knobs-into-holes" model proposed by Crick in 1953. Contacts between the helices include ion pairs and an extensive hydrophobic interface that contains a distinctive hydrogen bond. The conserved leucines, like the residues in the alternate hydrophobic repeat, make side-to-side interactions (as in a handshake) in every other layer of the dimer interface. The crystal structure of the GCN4 leucine zipper suggests a key role for the leucine repeat, but also shows how other features of the coiled coil contribute to dimer formation.
Gene Trees and the Origins of Inbred Strains of Mice
Authors: Atchley William R. , Fitch Walter M.
Published: October 2006

Extensive data on genetic divergence among 24 inbred strains of mice provide an opportunity to examine the concordance of gene trees and species trees, especially whether structured subsamples of loci give congruent estimates of phylogenetic relationships. Phylogenetic analyses of 144 separate loci reproduce almost exactly the known genealogical relationships among these 24 strains. Partitioning these loci into structured subsets representing loci coding for proteins, the immune system and endogenous viruses give incongruent phylogenetic results. The gene tree based on protein loci provides an accurate picture of the genealogical relationships among strains; however, gene trees based upon immune and viral data show significant deviations from known genealogical affinities.
Cloning and Expression of a Cocaine-Sensitive Rat Dopamine Transporter
Authors: Kilty John E. , Lorang Dominique , Amara Susan G.
Published: October 2006

The action of dopamine and other monoamine neurotransmitters at synapses is terminated predominantly by high-affinity reuptake into presynaptic terminals by specific sodium-dependent neurotransmitter transport proteins. A complementary DNA encoding a rat dopamine transporter has been isolated that exhibits high sequence similarity with the previously cloned norepinephrine and γ-aminobutyric acid transporters. Transient expression of the complementary DNA in HeLa cells confirms the cocaine sensitivity of this transporter.
Calcium Gradients Underlying Polarization and Chemotaxis of Eosinophils
Authors: Brundage Rodney A. , Fogarty Kevin E. , Tuft Richard A. , Fay Fredric S.
Published: October 2006

The concentration of intracellular free calcium ([Ca
2+
]
i
) in polarized eosinophils was imaged during chemotaxis by monitoring fluorescence of the calcium-sensitive dye Fura-2 with a modified digital imaging microscope. Chemotactic stimuli caused [Ca
2+
]
i
to increase in a nonuniform manner that was related to cell activity. In cells moving persistently in one direction, [Ca
2+
]
i
was highest at the rear and lowest at the front of the cell. Before cells turned, [Ca
2+
]
i
transiently increased. The region of the cell that became the new leading edge had the lowest [Ca
2+
]
i
. These changes in [Ca
2+
]
i
provide a basis for understanding the organization and local activity of cytoskeletal proteins thought to underlie the directed migration of many cells.
Interaural Phase Coding in Auditory Midbrain: Influence of Dynamic Stimulus Features
Authors: Spitzer Matthew W. , Semple Malcolm N.
Published: October 2006

A laterally located sound source stimulates the two ears at slightly different times, generating interaural phase disparities (IPDs) that are used for sound localization. Under natural conditions, such interaural cues are likely to be constantly changing, or dynamic. In the inferior colliculus of gerbils and cats, the nonlinearities in the coding of dynamic interaural phase cues are demonstrated. Responses to ecologically realistic phase cues are more reflective of the change of IPD than of the absolute IPDs over which that change occurs. This observation is inconsistent with the established view that directional information is coded in terms of absolute IPD.