bluuebunny/crossref_metadata_2025 huggingface dataset:
Decreased RNA Polymerase Activity in Mammalian Zinc Deficiency
Authors: Terhune M. W. , Sandstead H. H.
Published: October 2006

The activity of DNA-dependent RNA polymerase has been measured in liver nuclei from suckling rats nursed by zinc-deficient dams, or by controls that were either pair-fed or given free access to the diet. In the zinc-deficient pups, the activity of the enzyme did not increase; it fell after the tenth day of life.
Air Pollution: Sensitive Detection of Ten Pollutant Gases by Carbon Monoxide and Carbon Dioxide Lasers
Authors: Kreuzer L. B. , Kenyon N. D. , Patel C. K. N.
Published: October 2006

Detection sensitivities of a few parts per billion for ten gaseous pollutants have been evaluated by measuring the strength of the absorption of infrared radiation from carbon monoxide and carbon dioxide lasers. Ethylene concentrations as small as 5 parts per billion have been detected in air. The measured absorption strengths indicate that in mixtures of pollutants, such as nitrogen dioxide and water vapor, the sensitivity is reduced by overlapping absorption bands. However, calculations indicate that it should be possible to detect nitrogen dioxide concentrations of 0.01 part per million in the presence of water vapor concentrations of 10
5
parts per million.
Tumor Immunity in vitro: Destruction of a Mouse Ascites Tumor through a Cycling Pathway
Authors: Berke Gideon , Sullivan Karen A. , Amos D. Bernard
Published: October 2006

Lymphocytes in peritoneal exudate from BALB/c mice immunized against ascites leukemia EL4 are uniquely efficient at destroying
51
chromium-labeled EL4 cells in vitro. The lytic process depends upon the number of lymphocyte-tumor cell interactions. Effector lymphocytes are not inactivated as a result of lethal contact but can interact repeatedly with tumor cells.
Cuticle Deposition in Imaginal Disks: Effects of Juvenile Hormone and Fat Body in vitro
Authors: Oberlander H. , Tomblin C.
Published: October 2006

Wing disks from the last larval instar of the Indian meal moth,
Plodia interpunctella
(Hübner), were successfully cultured in modified Grace's medium. 20-Hydroxyecdysone induced cuticle deposition in these disks in vitro. This response was enhanced by treating the medium with larval fat body and was inhibited by application of juvenile hormone.
Rat Fighting Behavior: Serum Dopamine-β-Hydroxylase and Hypothalamic Tyrosine Hydroxylase
Authors: Lamprecht Friedhelm , Eichelman Burr , Thoa Nguyen B. , Williams Redford B. , Kopin Irwin J.
Published: October 2006

Male Sprague-Dawley rats were subjected to 4 weeks of daily periods of immobilization stress. One of two experimental groups was allowed 1 month of recovery. After 4 weeks of stress, there was a significant increase in shock-induced fighting, in the activity of serum dopamine-β-hydroxylase, and in the activity of hypothalamic tyrosine hydroxylase. The concentration of hypothalamic norepinephrine was not decreased. After 4 weeks of recovery, only serum dopamine-β-hydroxylase activity returned to normal; it therefore appears that long-term stress may increase central catecholamine synthesis. possibly resulting in a persistent increase in aggressive behavior.
Electronic Characterization of Solid Surfaces
Authors: Hagstrum Homer D.
Published: October 2006

At this point it would be presumptuous to suggest either that we understand very much about the electronic structure of solid surfaces or that we can specify in detail exactly what each of our tools for studying such structure is telling us. I think it is fair to say, however, that FES, UPS, and INS do make it possible for us to determine energy level spectra which can with some confidence be ascribed to the resonances of electrons in surface orbitals. It is true that INS is the more surface-selective of the two electron spectroscopies capable of producing data over at least a 10-ev energy range. We have seen intriguing differences between INS and UPS which, when we come to understand them, will most certainly reveal important characteristics of surface electronic structure and greatly expand our ability to distinguish electronic states in the surface from those in the selvedge. Possibly it is not too much to hope that the combined use of INS and UPS with incidence angle as an independent variable will give us information on the geometrical extent of surface orbitals, as well as the net electrical charge and the electric potential gradient in the region of the surface in which the orbitals lie.
Astronomical Applications of Differential Interferometry
Authors: Counselman C. C. , Hinteregger H. F. , Shapiro I. I.
Published: October 2006

Intercomparison of radio signals received simultaneously at several sites from several sources with small mutual angular separation provides a powerful astrometric tool. Applications include tracking the Lunar Rover relative to the Lunar Module, determining the moon's libration, measuring winds in Venus's lower atmosphere, mapping Mars radiometrically, and locating the planetary system in an inertial frame.
Paramyxovirus-Like Particles Associated with Acute Demyelination in Chronic Relapsing Multiple Sclerosis
Authors: Prineas John
Published: October 2006

Electron microscopy of small perivenous demyelinating lesions in a formalin-fixed brain of a multiple sclerosis subject revealed nuclear and cytoplasmic particles resembling paramyxovirus nucleocapsids. These particles, 18 to 20 nanometers in diameter, were found in mononuclear cells related to the central vein and infiltrating the zone of active demyelination. It is suggested that multiple sclerosis lesions may be initiated by seeding of lymphocytes bearing latent paramyxovirus to white matter of the central nervous system.
Sweet Taste of Water Induced by Artichoke (
Cynara scolymus
)
Authors: Bartoshuk Linda M. , Lee Chi-Hang , Scarpellino Richard
Published: October 2006

Exposure of the tongue to artichoke can make water taste sweet. Two major active components of artichoke are the salts of chlorogenic acid and cynarin. The sweetening of substances by temporarily modifying the tongue, rather than by adding a substance sweet in itself, may provide an alternative to currently used nonnutritive sweeteners.
S-100 Protein Synthesis by Isolated Polyribosomes from Rat Brain
Authors: Lerner Michael P. , Herschman Harvey R.
Published: October 2006

The radioactive proteins synthesized in a cell-free system and released from polyribosomes from rat brain were analyzed for the presence of a protein found only in the nervous system. Polyribosomes from rat liver were also studied to demonstrate the organ specificity of the radioactive product synthesized in vitro. The S-100 protein constituted 0.15 percent of the radioactive proteins released from brain polyribosomes.
Ultraviolet Reflection of a Male Butterfly: Interference Color Caused by Thin-Layer Elaboration of Wing Scales
Authors: Ghiradella Helen , Aneshansley Daniel , Eisner Thomas , Silberglied Robert E. , Hinton Howard E.
Published: October 2006

Males of the butterfly
Eurema lisa,
like many other members of the family Pieridae, reflect ultraviolet light. The color is structural rather than pigmentary, and originates from optical interference in a microscopic lamellar system associated with ridges on the outer scales of the wing. The dimensions and angular orientation of the lamellar system conform to predictions based on physical measurement of the spectral characteristics, including "color shifts" with varying angles of incidence, of the reflected ultraviolet light. The female lacks such scales and is consequently nonreflectant. The ultraviolet dimorphism supposedly serves as the basis for sexual recognition in courtship.
Blue-Green Algae: Why They Become Dominant
Authors: Shapiro Joseph
Published: October 2006

The injection of carbon dioxide and the addition of nitrogen and phosphorus to a lake population dominated by blue-green algae results in a rapid shift to dominance by green algae. The basis for the change and its implications are discussed.
Embryonic Chick Intestine in Organ Culture: Response to Vitamin D
3
and Its Metabolites
Authors: Corradino R. A.
Published: October 2006

Embryonic chick intestine maintained in organ culture responded to vitamin D
3
and its metabolites 25-hydroxycholecalciferol and 1,25-dihydroxycholecalciferol by synthesis of calcium-binding protein and enchanced calcium-45 uptake. The dihydroxy metabolite was by far the most potent inducer of the protein and also acted more rapidly than vitamin D
3
to stimulate isotope uptake. Despite its lower potency, vitamin D
3
itself was effective.
The Barrier to Internal Rotation in Ethane
Authors: Lowe J. P.
Published: October 2006

The internal rotation barrier in ethane appears susceptible to "explanation" at a qualitative, intuitively useful, reasonably correct level. At this level, localized and delocalized MO's each produce a description.

For a rigid rotation, the delocalized description is basically the "orbital control" type familiar from Woodward-Hoffmann rules, Walsh's rules, and the formation of diatomic molecules. This description indicates that long-range eclipsed H---H antibonding is responsible for the barrier. The equivalent localized-bond description invokes destructive interference or repulsion between eclipsed C-H bonds. The extension of this kind of description to other molecules requires care.

Subsequent to rigid rotation, the relaxation of ethane into its optimum eclipsed geometry produces almost no energy change but produces an unknown degree of energy "redistribution."

I have emphasized that the theoretical distinction between "orbital control" and "steric interaction" is not precise and that a clarification in terminology may be desirable in this connection.

The discussion of barriers given here applies only to a limited class of molecules, exemplified by ethane. No doubt, additional factors enter into a proper description of barriers in molecules having lower symmetry or more polar bonds, or both.

Finally, I should point out that approaches other than those in categories 1 to 3 have been made in efforts to rationalize or predict barriers to internal rotation. The Hellmann-Feynman theorem has been applied to find the torque on ethane at conformations between staggered and eclipsed . The integral Hellmann-Feynman theorem has served as a basis for discussing barriers in terms of transition densities and has led to an electrostatic model for barriers which has given some remarkably successful barrier predictions. These approaches are mathematically valid, and it is perfectly legitimate to try to extract physical explanations from them also. Thus, several valid explanations for the barrier to internal rotation in ethane are possible. However, I feel that the explanations proposed above in terms of delocalized or localized orbitals are preferable at present inasmuch as they are couched in terms and concepts currently in the mainstream of chemical thinking.
Assembly of Bacterial Ribosomes
Authors: Nomura Masayasu
Published: October 2006

I have not mentioned the remarkable progress made mainly by Fellner and his co-workers in the elucidation of the primary structure of rRNA's and by Wittmann and his co-workers in determining the structure of several ribosomal proteins. Such knowledge of primary structures is certainly the basis of complete understanding of the structure of the ribosome. With the current progress in technology, complete elucidation of the primary structure of all the ribosomal components is probably a matter of time. As indicated in this article, a rough approximation of the three-dimensional structure of ribosomes is likely to emerge soon. Although not mentioned in this article, studies of ribosomes from higher organisms are also progressing. We must, therefore, consider what further studies should be conducted and what kinds of questions we would like to solve.

Some groups of investigators aim to elucidate the complete three-dimensional structure of ribosomes and to find out how these complex cell organelles function; they hope to determine the conformational changes of many of the component molecules within the ribosome structure in response to external macromolecules and cofactors engaged in protein synthesis. Such knowledge will also be important in enabling us to understand the regulation of translation of genetic messages. Other groups of investigators aim to elucidate the complex series of events which originate in the transcription of the more than 60 genes and culminate in the formation of the specific structure of the organelle. Complete reproduction in vitro of all the assembly events that occur in vivo should not be difficult to achieve in principle. It should then become possible to study in vitro any factor regulating the biogenesis of the organelle. Although we do not know whether such studies would reveal any new fundamental principle that governs the complex circuits of interconnected macromolecular interactions, the achievement of such a complete in vitro system would represent a necessary step in the comprehensive understanding of biogenesis of organelles, and eventually, of the more complex behavior and genesis of cells.
Methylmercury: Bacterial Degradation in Lake Sediments
Authors: Spangler William J. , Spigarelli James L. , Rose Joseph M. , Miller Hope M.
Published: October 2006

During the first 50 days of a long-term period of incubation of lake sediments with inorganic mercury (Hg
2+
), low concentrations of methylinercury were observed to build up. Upon continued incubation there was a rapid decrease in amount of methylmercury in the system and a concomitant evolution of volatile inorganic mercury (Hg
0
). Transfer of the mixed culture to growth media containing methylmercury resulted in the degradation of methylmercury and the volatilization of Hg
0
. Four bacterial isolates were obtained from the mixed culture which, in pure culture, rapidly degraded methylmercury to methane and Hg
0
. The presence of methane in head space gases was confirmed by flameionization gas chromatography, and the presence of Hg
0
in head space gases was confirmed by mass spectrometry.
Arrested Development in Human Hookworm Infections: An Adaptation to a Seasonally Unfavorable External Environment
Authors: Schad G. A. , Chowdhury A. B. , Dean C. G. , Kochar V. K. , Nawalinski T. A. , Thomas J. , Tonascia J. A.
Published: October 2006

Contrary to general belief, larvae of
Ancylostoma duodenale
do not always develop directly to adulthood upon invasion of man. In West Bengal, India, arrested development appears to be a seasonal phenomenon which results in (i) reduction of egg output wasted in seeding an inhospitable environment and (ii) a marked increase in eggs entering the environment just before the monsoon begins.
Nerve Growth Factor: Enhanced Recovery of Feeding after Hypothalamic Damage
Authors: Berger Barry D. , Wise C. David , Stein Larry
Published: October 2006

A single intraventricular injection of nerve growth factor (NGF). given at the time of brain damage, facilitated the course of recovery from the lateral hypothalamic anorexic syndrome in male rats. In the second and third weeks after the trauma, NGF-treated rats ate more food, regained body weight more rapidly, and fed more vigorously in response to intraventricular administration of norepinephrine than untreated controls. After full recovery, rats that had been treated with NGF were resistant to reinstatement of the hypothalamic syndrome by 6-hydroxydopamine. NGF may facilitate behavioral recovery by promoting the development of supersensitivity to norepinephrine and possibly also by stimulating the growth of regenerating noradrenergic neurons in the brain.
Rate Constants for the Reactions of Hydroxyl and Hydroperoxyl Radicals with Ozone
Authors: DeMore William B.
Published: October 2006

Chain decomposition of ozone by hydroxyl and hydroperoxyl radicals has been observed. The rate constant at 3000°K for OH + O
3
→HO
2
+ O
2
is 8 × 10
-14
cubic centimeters per second. The rate constant for HO
2
+ O
3
→ OH + 2O
2
is 3 × 10
-15
cubic centimeters per second. These results have implications concerning stratospheric ozone.
Hypothermia of Broad-Tailed Hummingbirds during Incubation in Nature with Ecological Correlations
Authors: Calder William A. , Booser Joanna
Published: October 2006

The first continuous recordings of natural hypothermia, and the only evidences of hypothermia during incubation, were obtained from temperature sensors embedded in synthetic hummingbird eggs placed in the nests. Resorting to this energy-conserving process was infrequent and could be correlated with reduced opportunity for energy intake.
Alcohol-Induced Hyperlipidemia and Beta Lipoproteins
Authors: Mendelson Jack H. , Mello Nancy K.
Published: October 2006

Alcohol addicts with a primary type IV hyperlipoproteinemia show a striking elevation of triglycerides in the serum during long periods of alcohol consumption as compared with controls, without an accompanying significant increase in free fatty acids in the serum. These data suggest that this genetically related lipid abnormality may be a significant factor in the pathogenesis of alcohol hyperlipemia and the alcohol-induced fatty liver.
Common Mechanism for Repellents and Attractants in Bacterial Chemotaxis
Authors: Tsang Nora , Macnab Robert , Koshland D. E.
Published: October 2006

The migrational response of
Salmonella typhimurium
away from compounds such as phenol, indole, acetic acid, and leucine occurs because the bacteria tumble less frequently while
descending
gradients of repellents. This contrasts with their response of tumbling less frequently while ascending gradients of attractants. The results of competition experiments suggest that repellents, like attractants, operate through specific receptors, and the algebraic additivity experiments indicate that repellents and attractants utilize a common memory mechanism for taxis.
Reflex Compensation for Variations in the Mechanical Properties of a Muscle
Authors: Nichols T. Richard , Houk James C.
Published: October 2006

Soleus muscles of anesthetized cats were stretched and released by different amounts while their motor axons were stimulated. Muscle force increased, then gave way in response to large stretch. In the presence of active stretch reflexes in decerebrate cats, the give in force was absent. We demonstrate that autogenetic reflexes can compensate for variations in muscular stiffness revealed when responses to stretch and release are compared.
Human Papovavirus (JC): Induction of Brain Tumors in Hamsters
Authors: Walker Duard L. , Padgett Billie L. , ZuRhein Gabriele M. , Albert Albertina E. , Marsh Richard F.
Published: October 2006

Eighty-three percent of hamsters inoculated at birth with JC virus, a human papovavirus isolated from brain tissue of a case of progressive multifocal leukoencephalopathy, developed malignant gliomas within 6 months. Three brain tumors have been serially transplanted as subcutaneous tumors. JC virus was isolated from five of seven tumors tested. Cells from four tumors were cultivated in vitro. These cells contained an intranuclear antigen with the characteristics of a T antigen, and this antigen was antigenically related to SV40 T antigen. Although virus was not recovered from extracts of serially cultured tumor cells, JC virus was rescued when one tumor cell line was fused with permissive cells.
Detection of Charged Particles by Polymer Grafting
Authors: Monnin Michel M. , Blanford George E.
Published: October 2006

Tracks of fission fragments from a californium-252 source have been revealed by graft copolymerization. A 15 percent solution of propenoic (acrylic) acid monomer was reacted with irradiated cellulose triacetate for 24 hours at 55°C. Copolymer forms preferentially at the track sites and it can be dyed with rhodamine B because of its acid and hydrophylic properties. After the dyeing, the tracks were seen by using fluorescence microscopy.
Distal Conformation of the Thyroid Hormone 3,5,3′-Triiodo-L-Thyronine
Authors: Cody Vivian , Duax William L.
Published: October 2006

In the crystal structure of the thyroid hormone, 3,5,3′-triiodo-L-thyronine, the 3′ iodine is observed in the
distal
position, away from the alaninebearing ring of the thyroid hormone. This result had been anticipated from stereochemical and biological activity studies. However, previous observations of structures in which the 3′ iodine was
proximal
had cast some doubt on the stability of the 3′
distal
conformation. This observation suggests that the relative energies of the two conformers is similar and that perhaps the barrier to rotation is not as great as previously supposed since both the
distal
and
proximal
conformers have now been observed in the solid state.
Thermophilic Ostracod: Aquatic Metazoan with the Highest Known Temperature Tolerance
Authors: Wickstrom Conrad E. , Castenholz Richard W.
Published: October 2006

The upper lethal temperature for an ostracod of the genus
Potamocypris
collected from a thermal stream ranged from 49°C for incubation of more than 5 hours to 55.75°C for 1-minute incubations. Field collections were held at 35°C for less than 24 hours before experimental incubations. Calculated temperatures for 50 percent mortality for 60, 40, 20, 10, 5, and 1 minute of exposure were 50.44°, 50.96°, 51.43°, 52.03°, 52.77°, and 55.12°C, respectively.
Methyltetrahydrofolic Acid Mediates
N
- and
O
-Methylation of Biogenic Amines
Authors: Banerjee Shailesh P. , Snyder Solomon H.
Published: October 2006

A variety of mammalian and avian tissues
N
- and
O
-methylate indoleamines and phenylethylamines, with methyltetrahydrofolic acid as the methyl donor. Because it is considerably more efficient than
S
-adenosylmethionine, methyltetrahydrofolic acid may be the natural methyl donor in this reaction. With methyltetrahydrofolic acid, serotonin is
O
-methylated to 5-methoxytryptamine, a novel indoleamine in mammalian brain.
Vitamin B
12
and the Megaloblastic Development
Authors: Haurani Farid I.
Published: October 2006

In patients with vitamin B
12
deficiency, phytohemagglutinin-stimulated cultured lymphocytes had little or no thymidylate synthetase activity. Ample activity was found in such lymphocytes from normal individuals and patients with folic acid deficiency or pernicious anemia in remission. It therefore appears that the megaloblastosis that is associated with vitamin B
12
deficiency is related to low thymidylate synthetase activity.
Competitive Hydration of Quinazoline at the Montmorillonite-Water Interface
Authors: Bailey G. W. , Brown D. S. , Karickhoff S. W.
Published: October 2006

Ultraviolet spectroscopic analyses of suspensions of quinazoline and Na
+
-saturated montmorillonite have indicated that covalent hydration of the monovalent organic cation is inhibited at or near the clay surface. A similar lack of hydration was observed in solutions of quinazoline and high-ionic-strength calcium chloride. The inhibition is attributed to a local competition between quinazoline and the inorganic cations for water of hydration.
Errorless Discrimination, Autoshaping, and Conditioned Inhibition
Authors: Wessells Michael G.
Published: October 2006

Pigeons were exposed to a discriminated autoshaping procedure in which brief presentation of a green light on a key was always followed by food whereas presentation of a vertical white line on the key was never followed by food. Pigeons acquired an errorless discrimination by pecking reliably in the presence of the green light but never in the presence of the line. The line inhibited pecking in later tests: when the white line was paired with food, key peck acquisition was retarded; and when the white line was superimposed on the green background, responding was suppressed.
Control of Alternative Splicing by the Differential Binding of U1 Small Nuclear Ribonucleoprotein Particle
Authors: Kuo Hai-Chien , Nasim Faiz-Ul H. , Grabowski Paula J.
Published: October 2006

Cellular factors controlling alternative splicing of precursor messenger RNA are largely unknown, even though this process plays a central role in specifying the diversity of proteins in the eukaryotic cell. For the identification of such factors, a segment of the rat preprotachykinin gene was used in which differential expression of neuropeptides γ and K is dependent on alternative splicing of the fourth exon (E4). Sequence variants of the three-exon segment, (E3-E4-E5) were created, resulting in a sensitive assay for factors mediating the splicing switch between E4-skipping and E4-inclusion. A dinucleotide mutation in the 5′ splice site of E4 that increases base-pairing of this site to U1 small nuclear RNA resulted in uniform selection of E4, whereas a control mutation that destroyed base-pairing resulted in uniform E4-skipping. Affinity selection of spliceosomes formed on these functionally distinct substrates revealed that the extreme difference in splicing was mediated by differential binding of the U1 small nuclear ribonucleoprotein particle (snRNP) to the 5′ splice site of E4. These data show that, apart from its established role in selecting 5′ splice sites, U1 snRNP plays a fundamental role in 3′ exon selection and provides insight into possible mechanisms of alternative splicing.
Energetic Electrons in the Magnetosphere of Jupiter
Authors: Van Allen J. A. , Baker D. N. , Randall B. A. , Thomsen M. F. , Sentman D. D. , Flindt H. R.
Published: October 2006

Observations of energetic electrons (≳ 0.07 million electron volts) show that the outer magnetosphere of Jupiter consists of a thin disklike, quasitrapping region extending from about 20 to 100 planetary radii (
R
J
). This magnetodisk is confined to the vicinity of the magnetic equatorial plane and appears to be an approximate figure of revolution about the magnetic axis of the planet. Hard trapping is observed within a radial distance of about 20
R
J
. The omnidirectional intensity
J
0
of electrons with energy ≳ 21 million electron volts within the region 3 <
r
< 20
R
J
is given by the following provisional expression in terms of radial distance
r
and magnetic latitude θ:
J
0
= 2.1 × 10
8
exp[-(
r
/
a
) - (θ/
b
)
2
]. In this expression
J
0
is particles per square centimeter per second;
a
= 1.52
R
J
for 3 ≤
r
≤ 20
R
J
; and
b
= 15° for 3 ≤
r
≤ 10
R
J
, diminishing gradually for larger
r
. There is tentative evidence for mild effects of the Galilean satellite Europa and possibly Io and Ganymede but not Callisto.
Regeneration Electrode Units: Implants for Recording from Single Peripheral Nerve Fibers in Freely Moving Animals
Authors: Mannard Allan , Stein Richard B. , Charles Dean
Published: October 2006

Implantable electrode assemblies that become penetrated by regenerating axons were used to record signals from single sensory and motor nerve fibers associated with leg movement in unrestrained amphibians (
Xenopus laevis
). Such neuroimplants may provide a means for establishing the roles of various muscle afferents and efferents in posture and locomotion, and have potential clinical applications.
Ionic Basis of Hyperpolarizing Receptor Potential in Scallop Eye: Increase in Permeability to Potassium Ions
Authors: McReynolds John S. , Gorman A. L. F.
Published: October 2006

Photoreceptors of the distal retina of the scallop respond to light with a large hyperpolarizing receptor potential which is caused by a selective increase in permeability to potassium ions.
Lunar Surface: Identification of the Dark Mantling Material in the Apollo 17 Soil Samples
Authors: Pieters Carle , McCord Thomas B. , Charette Michael P. , Adams John B.
Published: October 2006

Evidence indicates that Apollo 17 sample 74001, a soil consisting of very dark spheres, is composed almost entirely of the dark mantling material that covers a large region of the southeastern boundary of Mare Serenitatis. Other Apollo 17 samples contain only a component of this material. The underlying basalt in the Taurus-Littrow valley appears to be an extension of material forming the low-albedo ring around part of Mare Serenitatis and much of the surface of Mare Tranquillitatis. The surface of this basalt region is spectrally distinct from areas with dark mantling material. These results are derived from telescopic and laboratory measurements of the optical properties of lunar soil. Digital vidicon color images are used to map the extent of these material units in the Taurus-Littrow region.
Defensive Use by an Insect of a Plant Resin
Authors: Eisner Thomas , Johnessee Judith S. , Carrel James , Hendry Lawrence B. , Meinwald Jerrold
Published: October 2006

Larvae of the sawfly
Neodiprion sertifer
(Hymenoptera: Diprionidae), when disturbed, discharge an oily oral effluent essentially identical chemically to the terpenoid resin of its host plant (
Pinus sylvestris
). The resin is sequestered by the larva upon feeding, and stored in two compressible diverticular pouches of the foregut. The fluid is effectively deterrent to predators. The defensive use by an insect of a plant resin provides an instance of secondary utilization by a herbivore of the protective chemical weaponry of its host.
Regulation of Bacterial Growth
Authors: Nierlich Donald P.
Published: October 2006

Is the control of bacterial metabolism so complex? The answer can be found in a simple experiment. Two cultures of bacteria are grown in different mediums. One contains as the carbon and nitrogen sources a mixture of amino acids, while the other contains only glucose and ammonia, so that the cells must synthesize all of the amino acids. The results show that insofar as the cells in both cultures grow at comparable rates, they will have the same composition in terms of DNA, RNA, and protein. To explain this phenomena I have argued that through the control mechanisms responsible for the distribution of substrates in intermediary metabolism, the substrates of protein synthesis are produced at concentrations and rates commensurate with the ability of the environment to support growth. The provision of these substrates relative to the ability of the protein forming system to utilize them regulates the synthesis of ribosomal and transfer RNA, which, after adjustment for various modulating influences, such as nonfunctioning ribosomes or ribosomal RNA turnover, brings the number of functioning ribosomes to a point in keeping with the provision of external nutrients. The synthesis of messenger (or total) RNA, ribosomal proteins, and DNA, and the process of cell division, for example, are subject to their own controls, but through the burden they each place on intermediary metabolism, they provide a means for partitioning the cell's metabolic resources. It might be noted that this view may not be very far from the idea once held that the rate at which each of the transfer RNA's was changed by amino acids regulate the synthesis of bacterial RNA, but growth regulation is clearly more complicated than implied by that model.
Spectroscopy of Biological Compounds with Inelastic Electron Tunneling
Authors: Hansma Paul K. , Coleman R. V.
Published: October 2006

Metal-insulator-metal electron tunnel junctions can be doped with a solution of an organic compound by placing a drop of the solution on the insulator and spinning off the excess. Electrical measurement of the second derivative of voltage with respect to current, as a function of applied voltage, then gives a spectrum of vibrational modes equivalent to an infrared or Raman spectrum, but with the use of only micrograms of sample.
Identification of a Gene Located at Chromosome 5q21 that Is Mutated in Colorectal Cancers
Authors: Kinzler Kenneth W. , Nilbert Mef C. , Vogelstein Bert , Bryan Tracy M. , Levy Daniel B. , Smith Kelly J. , Preisinger Antonette C. , Hamilton Stanley R. , Hedge Phil , Markham Alex , Carlson Mary , Joslyn Geoff , Groden Joanna , White Ray , Miki Yoshoi , Miyoshi Yasuo , Nishisho Isamu , Nakamura Yusuke
Published: October 2006

Recent studies have suggested the existence of a tumor suppressor gene located at chromosome region 5q21. DNA probes from this region were used to study a panel of sporadic colorectal carcinomas. One of these probes, cosmid 5.71, detected a somatically rearranged restriction fragment in the DNA from a single tumor. Further analysis of the 5.71 cosmid revealed two regions that were highly conserved in rodent DNA. These sequences were used to identify a gene, MCC (
m
utated in
c
olorectal
c
ancer), which encodes an 829-amino acid protein with a short region of similarity to the G protein-coupled m3 muscarinic acetylcholine receptor. The rearrangement in the tumor disrupted the coding region of the MCC gene. Moreover, two colorectal tumors were found with somatically acquired point mutations in MCC that resulted in amino acid substitutions. MCC is thus a candidate for the putative colorectal tumor suppressor gene located at 5q21. Further studies will be required to determine whether the gene is mutated in other sporadic tumors or in the germ line of patients with an inherited predisposition to colonic tumorigenesis.
Streamflow Greatly Reduced by Converting Deciduous Hardwood Stands to Pine
Authors: Swank Wayne T. , Douglass James E.
Published: October 2006

Fifteen years after two experimental watersheds in the southern Appalachians had been converted from a mature deciduous hardwood cover to white pine, annual streamflow was reduced about 20 centimeters (20 percent) below that expected for the hardwood cover. Streamflow was reduced during every month, with the largest monthly reductions (1.5 to 3.5 centimeters) occurring in the dormant and early growing seasons.
Melatonin: Its Inhibition of Pineal Antigonadotrophic Activity in Male Hamsters
Authors: Reiter R. J. , Vaughan M. K. , Blask D. E. , Johnson L. Y.
Published: October 2006

Exposure of male hamsters to short daily photoperiods (1 hour of light and 23 hours of darkness daily for 9 weeks led to total involution of the testes and accessory sex organs (seminal vesicles and coagulating glands). Pituitary levels of immunoreactive prolaction also decreased by about 60 percent after dark exposure. The inhibitory effects of darkness on the reproductive organs were prevented either by pinealectomy or by the subcutaneous implantation of a melatonin-beeswax pellet into the animals each week. Both pinealectomy and melatonin treatment also returned pituitary levels of prolactin toward normal. The results suggest that melatonin is not the pineal antigonadotrophic factor in the male golden hamster.
Deposits of Amyloid β Protein in the Central Nervous System of Transgenic Mice
Authors: Wirak D. O. , Bayney R. , Ramabhadran T. V. , Fracasso R. P. , Hart J. T. , Hauer P. E. , Hsiau P. , Pekar S. K. , Scangos G. A. , Trapp B. D. , Unterbeck A. J.
Published: October 2006

Alzheimer's disease is characterized by widespread deposition of amyloid in the central nervous system. The 4-kilodalton amyloid β protein is derived from a larger amyloid precursor protein and forms amyloid deposits in the brain by an unknown pathological mechanism. Except for aged nonhuman primates, there is no animal model for Alzheimer's disease. Transgenic mice expressing amyloid β protein in the brain could provide such a model. To investigate this possibility, the 4-kilodalton human amyloid β protein was expressed under the control of the promoter of the human amyloid precursor protein in two lines of transgenic mice. Amyloid β protein accumulated in the dendrites of some but not all hippocampal neurons in 1-year-old transgenic mice. Aggregates of the amyloid β protein formed amyloid-like fibrils that are similar in appearance to those in the brains of patients with Alzheimer's disease.
Insulin Secretion by Anomers of D-Glucose
Authors: Niki Atsushi , Niki Hatsumi , Miwa Ichitomo , Okuda Jun
Published: October 2006

Isolated rat islets were incubated for 5 minutes in the media containing either the α or β anomer of D-glucose (2 milligrams per milliliter). The amounts of secreted insulin and changes of anomers ratio were concomitantly determined. In spite of rapid mutarotation, significantly greater stimulation of insulin secretion was observed by α-D-glucose as compared with β-D-glucose.
N
′-Nitrosonornicotine in Tobacco
Authors: Hoffmann Dietrich , Hecht Stephen S. , Ornaf Raphael M. , Wynder Ernst L.
Published: October 2006

N
′-Nitrosonornicotine, a potential carcinogen, has been positively identified in unburned tobacco. The amount in commercial U.S. tobacco products is between 1.9 to 88.6 parts per million, one of the highest values of an environmental nitrosamine yet reported. The amount in food and drink rarely exceeds 0.1 part per million. This compound is the first example of a potential organic carcinogen isolated from tobacco.
Death of American Ground Sloths
Authors: Long Austin , Martin Paul S.
Published: October 2006

Organic remains, especially dung, of extinct ground sloths provide ideal material for radiocarbon dating. Rampart Cave, Arizona, revealed periodic occupation at intervals by the Shasta ground sloth from before 40,000 years ago until 11,000 years ago. Dates from other caves in the arid Southwest indicate that the Shasta ground sloth disappeared at or very soon after the time of Clovis big game hunters. Ground sloth remains in South America are slightly younger. The timing of ground sloth extinction is in accord with the model of explosive overkill.
Department of Defense R & D in the University
Authors: Glantz Stanton A. , Albers Norm V.
Published: October 2006

The DOD carefully evaluates its technical needs and executes programs of sponsored research and development to fulfill them. Thus, while individual projects proceed in accordance with established scientific principles of objectivity, the overall system of DOD funding allows the military to influence the development of science technology. Many have argued that this system of contracts and grants has well served science and the universities. One cannot deny that the influx of money led to rapid progress in selected scientific fields and increased scientific institutions' affluence. With this fact we have no quarrel. However, these same people often continue to argue that the systems of federal funding for science, specifically DOD funding of science, follows merely on the work's scientific merit, not on how it fits any larger scheme. They continue, that, since DOD supports good science for its own sake, the combination of military money and universities strongly encouraging faculty to seek that money encourages healthy competition for faster scientific progress. The DOD's approval process is seen to follow from the scientist up, with the military deciding which proposals for research have the most intrinsic (scientific) merit, then after the fact, thinking up a military justification for congressional budget requests. It is this latter belief with which we take issue. The DOD considers the scientific worth of the proposals for research it receives, but only after it has determined that the proposal fulfills a specific military need.

This fact and its implications for the university as an institution charged with protecting the process by which man discovers new knowledge have been ignored in the debates over DOD sponsored research and development in universities. In addition, the Nixon Administration's efforts to tighten management controls over civilian research, especially in the biomedical and energy areas, promises to further undermine the university's role as an institution charged with fostering a search for truth free from bias in both methodology and subject selection.
Trace Gas Analysis of Power Plant Plumes Via Aircraft Measurement: O
3
, NO
x
, and SO
2
Chemistry
Authors: Davis D. D. , Smith G. , Klauber G.
Published: October 2006

The gaseous plume from an isolated 1000-megawatt power plant was systematically examined from a single engine aircraft to determine the extent to which NO
x
and SO
2
, chemistry occurs as a function of distance. The concentrations of ambient ozone, water vapor, and hydroxyl free radicals are indicated to be of major importance in defining the chemistry of power plant plumes during summertime conditions.
Blood Velocity Measurements in Human Retinal Vessels
Authors: Tanaka Toyoichi , Riva Charles , Ben-Sira Isaac
Published: October 2006

Laser Doppler velocimetry was used to measure the velocity of blood in human retinal vessels. The mean flow velocities obtained were 1.9 centimeters per second in a retinal vein and 2.2 centimeters per second in a retinal artery. Scattered light from a weak helium-neon laser beam focused on the vessel was detected by a photomultiplier, and the temporal correlation of the intensity fluctuations was measured with a photon counting autocorrelator. Autocorrelation functions for blood flowing through glass capillaries were used for calibration.
Hemoglobin Kinetics and the Effect of Organic Phosphates
Authors: Bansil Rama , Herzfeld Judith , Stanley H. Eugene
Published: October 2006

A kinetic model based on allosteric mechanisms of cooperativity fits the experimentally observed phosphate dependence of hemoglobin reactions. Subunit inequivalence is found to be important in analyzing hemoglobin kinetics. The observed increase in the rate of deoxygenation in the presence of organic phosphates is primarily related to the increased rate of dissociation of the second oxygen molecule.
Ethanol Inhibition of Vitamin A Metabolism in the Testes: Possible Mechanism for Sterility in Alcoholics
Authors: Van Thiel David H. , Gavaler Judith , Lester Roger
Published: October 2006

Vitamin A (retinol) is essential for spermatogenesis. Alcohol dehydrogenase, the enzyme responsible for ethanol metabolism, is also required for the conversion of retinol to bioactive retinal at the end organ site. Ethanol inhibits the oxidation of retinol by testicular homogenates containing alcohol dehydrogenase. Thus, a possible biochemical mechanism for the sterility of chronic alcoholics is identified.
Vermetid Gastropods and Intertidal Reefs in Israel and Bermuda
Authors: Safriel Uriel N.
Published: October 2006

Small-rimmed intertidal reefs develop in the subtropical marine waters of Israel and Bermuda when erosion of exposed promontories is arrested by vermetid gastropods. The reefs in Bermuda are actively growing, wave-resistant biogenic structures, while those in Israel are limestone structures only encrusted by a relatively thin layer of vermetid shells cemented by coralline algae.
Viral Infection and Host Defense
Authors: Carter William A. , De Clercq Erik
Published: October 2006

Double-stranded RNA, made as an intermediary substance in the replication of most, if not all, viruses, may play a much more important role in the pathogenesis and the recovery from virus infections than has hitherto been suspected. Apparently, dsRNA is used by both the challenge virus and the host cell in an attempt to gain "molecular control." Double-stranded RNA exerts a set of effects, which may be well balanced, not only at the level of the individual cell but also at the complex assemblage of these cells termed the organism (Fig. 1). In the cell, interferon synthesis is triggered, although interferon mRNA translation may not occur if dsRNA shuts off protein synthesis too quickly. In the whole organism, the disease severity will depend on how certain toxic reactions evoked by infection (such as cell necrosis and fever) are counterbalanced by an increase in the host defense mechanisms (for example, immune responsiveness and interferon production).
Many aspects of the response, relating to either progress of, or recovery from, the disease, can be explained on the basis of a dsRNA.

In addition to drawing attention to the biodynamic role of dsRNA, our hypothesis suggests specific experimental vectors designed to enhance our information on the molecular basis of the morbid process which occurs with viral infection. Finally, we suggest that, although the dsRNA molecule may be viewed as a rather simple unit structure, the opportunity for further diversity in the biological activity of a given dsRNA molecule always exists. Namely, each deviation from a perfectly double-helical arrangement introduces the possibility for emphasizing one biological reactivity at the expense of another. This latter structure-activity property may partially account for the extreme apparent diversity, commonly encountered, in the presentations of virologic illness.

Appendix note added in proof
. Subsequent to submission of this text, we have found that the potent mitogen effect of dsRNA for lymphocytes (murine and human) is also exquisitively sensitive to the fidelity in base pairing of the input polymer pair (
59
). For example, infrequent "loops" (one nucleotide per 20 base pairs) in an otherwise perfectly helical rI

n

⋅ rC

n

molecule [for example, rI

n

⋅ r(C
19,
U)

n

] strongly changes its mitogenic properties. This observation, which supports our thesis that a "fine structure" term can be developed for other reactions triggered by dsRNA's in biological systems, emphasizes that diverse biological effects may be encountered with an ostensibly uniform family of dsRNA's.
Alteration of the Phase and Period of a Circadian Oscillator by a Reversible Transcription Inhibitor
Authors: Raju Uma , Koumenis Constantinos , Nunez-Regueiro Marta , Eskin Arnold
Published: October 2006

A function for transcription in the mechanism of a circadian oscillator was investigated with the reversible transcription inhibitor 5,6-dichloro-1-β-D-ribobenzimidazole (DRB). Two-hour treatments with DRB shifted the phase of the circadian rhythm of the isolated eye of
Aplysia
, and continuous treatments of DRB lengthened the free running period of this rhythm. Camptothecin, an inhibitor of transcription that is structurally unrelated to DRB, had similar effects on the circadian rhythm. These results suggest that transcription may be part of the circadian oscillating mechanism.
Purification of an Allene Oxide Synthase and Identification of the Enzyme as a Cytochrome P-450
Authors: Song Wen-Chao , Brash Alan R.
Published: October 2006

Fatty acid hydroperoxides (lipoxygenase products) are metabolized to allene oxides by a type of dehydrase that has been detected in plants, corals, and starfish oocytes. The allene oxides are unstable epoxide precursors of more complex products such as jasmonic acid, the plant growth hormone. Characterization of the dehydrase enzyme of flaxseed revealed that it is a 55-kilodalton hemoprotein. The spectral characteristics of this dehydrase revealed it to be a cytochrome P-450. It operates with the remarkable activity of ≥1000 turnovers per second. The results establish a new catalytic activity for a cytochrome P-450 and illustrate the cooperation of different oxygenases in pathways of fatty acid metabolism.
Collagenase Production by Rheumatoid Synovial Cells: Stimulation by a Human Lymphocyte Factor
Authors: Dayer Jean-Michel , Russell R. Graham G. , Krane Stephen M.
Published: October 2006

Human peripheral blood lymphocytes incubated in culture for 1 to 3 days at 37°C, but not at 4°C, release a soluble factor which can stimulate, up to 400-fold, collagenase production by isolated, adherent, rheumatoid synovial cells. Production of lymphocyte factor is enhanced by phytohemagglutinin or concanavalin A. By gel filtration the factor has an apparent molecular weight of about 12,000.
Permethylpolysilanes: Silicon Analogs of Hydrocarbons
Authors: West Robert , Carberry Edward
Published: October 2006

Studies of the spectra of cyclopolysilanes have led to several significant conclusions. These molecules possess both easily ionized Si-Si bonding electrons and low energy delocalized antibonding orbitals, and can therefore serve either as electron donors or acceptors. This model explains the similarity in properties between cyclopolysilanes and aromatic hydrocarbons. Further investigations of cyclopolysilanes seem likely to provide the key to understanding of controversial questions of bonding in metalloid compounds even as studies of their carbon analogs, the cyclic and cage hydrocarbons, have been crucial to present knowledge of organic stereochemistry and reaction mechanisms.

The reactions of cyclopolysilanes are not only interesting in themselves, but have opened the way to the synthesis of complex polysilanes and thus to whole new areas of study. Improved methods of synthesis and isolation are needed, but the number and kinds of compounds that can be prepared seem almost limitless. Perhaps a polymetal chemistry comparable in breadth and variety to carbon chemistry is now developing.