bluuebunny/crossref_metadata_2025 huggingface dataset:
Conversion of Thyroxine to Triiodothyronine in Normal Human Subjects
Authors: Sterling Kenneth , Brenner Milton A. , Newman Edward S.
Published: October 2006

The conversion of thyroxine to triiodothyronine, previously demonstrated in athyreotic human subjects, has been investigated in normal subjects who were given intravenous injections of purified thyroxine labeled with carbon-14 in ring A and in the alanine side chain. Evidence for the conversion of T4 to T3 was provided by the finding of carbon-14 in the T3 fraction isolated from serums. It is estimated that an appreciable fraction of T4 may be transformed to T3 in normal man.
Tilorone Hydrochloride: An Orally Active Antiviral Agent
Authors: Krueger Russell F. , Mayer Gerald D.
Published: October 2006

Tilorone hydrochloride, 2,7-bis[2-(diethylamino)ethoxy]fluoren-9-one dihydrochloride, given orally to mice before they are infected is active against at least nine viruses of both RNA and DNA groups. The compound is effective when given prophylactically; the optimum time of treatment depends on the route of infection.
Tilorone Hydrochloride: Mode of Action
Authors: Mayer Gerald D. , Krueger Russell F.
Published: October 2006

An antiviral serum component is found in mice treated orally with tilorone hydrochloride. The active material fulfills sufficient biological criteria to be classified as an interferon.
Molecular Targets for AIDS Therapy
Authors: Mitsuya Hiroaki , Yarchoan Robert , Broder Samuel
Published: October 2006

The development of antiretroviral therapy against acquired immunodeficiency syndrome (AIDS) has been an intense research effort since the discovery of the causative agent, human immunodeficiency virus (HIV). A large array of drugs and biologic substances can inhibit HIV replication in vitro. Nucleoside analogs—particularly those belonging to the dideoxynucleoside family—can inhibit reverse transcriptase after anabolic phosphorylation. 3′-Azido-2′,3′-dideoxythymidine (AZT) was the first such drug tested in individuals with AIDS, and considerable knowledge of structure-activity relations has emerged for this class of drugs. However, virtually every step in the replication of HIV could serve as a target for a new therapeutic intervention. In the future, non-nucleoside-type drugs will likely become more important in the experimental therapy of AIDS, and antiretroviral therapy will exert major effects against the morbidity and mortality caused by HIV.
Body Temperature: Possible Ionic Mechanism in the Hypothalamus Controlling the Set Point
Authors: Myers R. D. , Veale W. L.
Published: October 2006

The body temperature of many mammals is set at or around 37°C. The mechanism for this set point appears to depend on a constant and inherent balance between sodium and calcium ions within the posterior hypothalamus. When this region is perfused in unanesthetized cats, an extracellular excess or a normal physiological concentration of sodium ions evokes a rise in body temperature if calcium is not in the perfusate. At the same site, an excess or normal concentration of calcium ions causes the temperature to fall when sodium is absent.
Strain C3H-A
vy
fB Mice: Ninety Percent Incidence of Mammary Tumors Transmitted by Either Parent
Authors: Vlahakis G. , Heston W. E. , Smith G. H.
Published: October 2006

Mammary tumorigenesis in C3H-A
vy
fB female mice is not due to milk-borne mammary tumor virus but to factors transmitted at conception. Prominent among these is the
A
vy
gene which may increase the virulence or transmissibility of a variant of mammary tumor virus vertically transmitted by either parent, or may increase the tumorigenic response of the mammary tissue. These factors together with the influence of hormones of pregnancy resulted in the high incidence observed.
Cell Communication, Calcium Ion, and Cyclic Adenosine Monophosphate
Authors: Rasmussen Howard
Published: October 2006

The hypothesis advanced in this article requires further validation. Undoubtedly it will require modification as our knowledge of biochemical control increases. Nevertheless, it should prove useful in focusing attention on the apparent similarity in the response of a large number of specific cell types to particular stimuli. Emphasis has been placed on a few common and apparently key elements in these responses. It is recognized that other factors are undoubtedly involved. Specifically, the changes in membrane potentials indicate the likelihood of widespread changes in the properties of the cell membrane, for example, changes in Na
+
and K
+
transport and distribution. These aspects of cellular responses may eventually prove to be of equal or greater importance than those common aspects of the system already identified.
Heating of Basalts with a Carbon Dioxide Laser
Authors: Blander Milton , Keil Klaus , Nelson Lloyd S. , Skaggs Samuel R.
Published: October 2006

Basalts heated strongly with focused infrared laser radiation vaporized and splattered. Electron microprobe analyses of condensate, ejecta, and residue show strong vapor fractionation trends which, for some elements, are different from what would be expected theoretically and from previously reported data on more siliceous materials. It appears that solution effects can account for these differences. Heating of materials by a powerful focused laser beam for the purpose of study of vapor fractionation is a convenient technique that is more versatile than previous methods such as heating in solar or arc image furnaces.
Specific Inhibition of Nuclear RNA Polymerase II by α-Amanitin
Authors: Lindell Thomas J. , Weinberg Fanyela , Morris Paul W. , Roeder Robert G. , Rutter William J.
Published: October 2006

α-Amanitin, a toxic substance from the mushroom
Amanita phalloides
, is a potent inhibitor of DNA-dependent RNA polymerase II (the nucleoplasmic form) from sea urchin, rat liver, and calf thymus. This compound exerts no effect on the activity of polymerase I (nucleolar form) or polymerase III (also nucleoplasmic). The inhibition is due to a specific interaction with polymerase II or with a complex of DNA and polymerase II.
Mercury Compounds Reduce Photosynthesis by Plankton
Authors: Harriss Robert C. , White David B. , Macfarlane Robert B.
Published: October 2006

Concentrations of organomercurial fungicides as low as 0.1 part per billion in water reduced photosynthesis and growth in laboratory cultures of one species of marine diatom and several natural phytoplankton communities from Florida lakes. The acute toxicity of mercury compounds to phytoplankton is dependent on the chemical nature of the mercury compound and on cell concentrations.
Glue Sniffing Causes Heart Block in Mice
Authors: Taylor George J. , Harris Willard S.
Published: October 2006

In mice, the inhalation of airplane glue or toluene fumes slows the sinoatrial rate, prolongs the P-R interval, and sensitizes the heart to asphyxia-induced atrioventricular block. In humans who sniff glue or solvents, similar mechanisms may be a cause of sudden death.
Sulfur Isotope Distribution in Solfataras, Yellowstone National Park
Authors: Schoen Robert , Rye Robert O.
Published: October 2006

Sulfur isotope data on hydrogen sulfide, native sulfur, and sulfates from acid hot-spring areas at Yellowstone National Park suggest that hydrogen sulfide oxidizes to sulfur abiologically, whereas sulfur undergoes biological oxidation to sulfuric acid. An exception occurs at Mammoth Hot Springs where hydrogen sulfide apparently undergoes biochemical oxidation to sulfur.
Mechanisms Controlling World Water Chemistry
Authors: Gibbs Ronald J.
Published: October 2006

On the basis of analytical chemical data for numerous rain, river, lake, and ocean samples, the three major mechanisms controlling world surface water chemistry can be defined as atmospheric precipitation, rock dominance, and the evaporation-crystallization process.
Water Drop Freezing: Ejection of Microdroplets
Authors: Cheng Roger J.
Published: October 2006

The ejection of microdroplets from the surface of a freezing supercooled water drop has been observed and photographed. The fragmentation of a freezing drop in the forms of splintering, shattering, or bursting has been known for some time. This newly observed phenomenon of the ejection of numerous microdroplets, the duration of their ejection, and the electrical properties of these droplets suggest a possible mechanism of charge generation in thunderstorms.
Association of B Cell Antigen Receptor with Protein Tyrosine Kinase Lyn
Authors: Yamanashi Yuji , Kakiuchi Terutaka , Mizuguchi Junichiro , Yamamoto Tadashi , Toyoshima Kumao
Published: October 2006

Antigen is thought to cross-link membrane-bound immunoglobulins (Igs) of B cells, causing proliferation and differentiation or the inhibition of growth. Protein tyrosine kinases are probably involved in signal transduction for cell proliferation and differentiation. The Src-like protein tyrosine kinase Lyn is expressed preferentially in B cells. The Lyn protein and its kinase activity could be coimmunoprecipitated with IgM from detergent lysates. Cross-linking of membrane-bound IgM induced a rapid increase in tyrosine phosphorylation of at least ten distinct proteins of B cells. Thus, Lyn is physically associated with membrane-bound IgM, and is suggested to participate in antigen-mediated signal transduction.
ACh Receptor-Rich Membrane Domains Organized in Fibroblasts by Recombinant 43-Kilodalton Protein
Authors: Phillips William D. , Kopta Carrie , Blount Paul , Gardner Paul D. , Steinbach Joe Henry , Merlie John Paul
Published: October 2006

Neurotransmitter receptors are generally clustered in the postsynaptic membrane. The mechanism of clustering was analyzed with fibroblast cell lines that were stably transfected with the four subunits for fetal (α, β, γ, δ) or adult (α, β, ε, δ) type mouse muscle nicotinic acetylcholine receptors (AChRs). Immunofluorescent staining indicated that AChRs were dispersed on the surface of these cells. When transiently transfected with an expression construct encoding a 43-kilodalton protein that is normally concentrated under the postsynaptic membrane, AChRs expressed in these cells became aggregated in large cell-surface clusters, colocalized with the 43-kilodalton protein. This suggests that 43-kilodalton protein can induce AChR clustering and that cluster induction involves direct contact between AChR and 43-kilodalton protein.
Enhancement of HIV-1 Cytocidal Effects in CD4
+
Lymphocytes by the Aids-associated Mycoplasma
Authors: Lo Shyh-Ching , Tsai Shien , Benish Janet R. , Shih James Wai-Kuo , Wear Douglas J. , Wong Dennis M.
Published: October 2006

Coinfection with
Mycoplasma fermentans
(incognitus strain) enhances the ability of human immunodeficiency virus type-1 (HIV-1) to induce cytopathic effects on human T lymphocytes in vitro. Syncytium formation of HIV-infected T cells was essentially eliminated in the presence of
M. fermentans
(incognitus strain), despite prominent cell death. However, replication and production of HIV-1 particles continued during the coinfection. Furthermore, the supernatant from cultures coinfected with HIV-1 and the mycoplasma contained a factor that inhibited the standard reverse transcriptase enzyme assay. The modification of the biological properties of HIV-1 by coinfection with mycoplasma may be involved in the pathogenesis of acquired immunodeficiency syndrome (AIDS).
Vitamin D: A Cholecalciferol Metabolite Highly Active in Promoting Intestinal Calcium Transport
Authors: Myrtle James F. , Norman Anthony W.
Published: October 2006

A major polar metabolite of cholecalciferol (vitamin D
3
) obtained from chick intestines is over four times as effective as cholecalciferol and over two times as effective as 25-hydroxycholecalciferol in stimulating intestinal calcium transport 24 hours after administration. Following a considerable lag, cholecalciferol and its 25-hydroxy derivative produce a maximum stimulation of the transport response at 24 to 48 hours. The polar intestinal metabolite greatly shortens this lag, stimulating maximum calcium transport by 9 hours. At 9 hours this metabolite is at least 13 times as active as the parent cholecalciferol and as such is a likely candidate for the biologically active form of cholecalciferol in the intestine.
Computer-Based Interviewing System Dealing with Nonverbal Behavior as well as Keyboard Responses
Authors: Slack Warner
Published: October 2006

A digital computer has been programmed to conduct a medical interview while simultaneously monitoring the heart rate and keyboard response latency of the respondent for each question frame. The program can branch to new frames contingent upon the heart rate and response latency values, as well as the keyboard responses, and thus alter the course of the interview on the basis of this nonverbal information. The program is presented as a technique for studying the use of nonverbal respondent behavior in automated, clinical interviews.
Olfactory Bulb Removal Eliminates Maternal Behavior in the Mouse
Authors: Gandelman Ronald , Zarrow M. X. , Denenberg Victor H. , Myers Michael
Published: October 2006

Olfactory bulb removal eliminated maternal behavior in lactating and in virgin mice. The results are in contrast to the generally accepted concept of multisensory control of mammalian maternal behavior.
Induction of Liver Acetaldehyde Dehydrogenase: Possible Role in Ethanol Tolerance after Exposure to Barbiturates
Authors: Redmond Geoffrey , Cohen Gerald
Published: October 2006

Mice were injected twice a day for 4 days with saline or phenobarbital or ethanol. Treatment with phenobarbital, but not ethanol, increased the amount of liver acetaldehyde dehydrogenase activity. More rapid removal of acetaldehyde, which is a toxic metabolic intermediate of ethanol, may contribute to the alcohol tolerance exhibited by persons who use barbiturates regularly.
Opal Precipitation by Marine Gastropods (Mollusca)
Authors: Lowenstam Heinz A.
Published: October 2006

The high silicon content of certain radular sites of the Patellacea (Mollusca, Gastropoda) is shown by infrared absorption spectrums to be fixed in the form of the mineral opal. Opal and goethite mineralize the cusps and bases of the teeth. The presence of opalized base plates only in the families Acmaeidae and Lepetidae appears to be of taxonomic significance. Minimum values of the volume of fixation and of the turnover rate of opal by the Patellacea are calculated to assess the role of this previously neglected taxon in biological fixation of silica in the oceans. The significance of these organisms points to the much needed study of the silica transport system in tissue-grade Metazoa.
Kaolinite: Synthesis at Room Temperature
Authors: Linares J. , Huertas F.
Published: October 2006

To obtain kaolinite at low temperature and pressure from the system Si(OH)
4
-Al
3+
-H
2
O, the sixfold coordination of aluminum is a necessary prerequisite. Kaolinite was synthesized at
p
H values from 2 to 9 and with a ratio of SiO
2
to Al
2
O
3
in solution from 1 to 10 by means of the complexation of Al
3+
and fulvic acid.
Scleroderma and the Subcutaneous Tissue
Authors: Fleischmajer Raul , Damiano Victor , Nedwich Alexander
Published: October 2006

Our study revealed that as observed with both light and electron microscopy the most specific abnormality in scleroderma skin is the replacement of the subcutaneous tissue by markedly abnormal connective tissue.
Adenosine 3′,5′-Monophosphate in Reproducing and Differentiated Trypanosomes
Authors: Strickler James E. , Patton Curtis L.
Published: October 2006

Trypanosoma lewisi
, a blood protozoan of rats, undergoes differentiation from a rapidly reproducing form to a nonreproducing form in response to the host antibody ablastin. Intracellular concentrations of adenosine 3′,5′-monophosphate (cyclic AMP), which has been implicated in controlling reproduction in cultured mammalian cells, was measured in the two developmental forms of
T. lewisi
. The concentrations were significantly different, and the results support a hypothesis under which ablastin stimulates an increase in intracellular cyclic AMP.
Norepinephrine Biosynthesis Inhibition: Effects on Memory in Mice
Authors: Randt Clark T. , Quartermain David , Goldstein Menek , Anagnoste Berta
Published: October 2006

Diethyldithiocarbamate, a dopamine beta hydroxylase inhibitor, decreases biosynthesis of norepinephrine in the brain. The effects of this inhibitor coincide with alterations in memory as demonstrated in single-trial passive avoidance in C57BL/6J mice.
Acadian Orogeny: An Abrupt and Brief Event
Authors: Naylor Richard S.
Published: October 2006

Rubidium-strontium dating indicates the Barre-type granites in eastern Vermont were emplaced at least 380 × 10
6
years ago. This result suggests the Acadian orogeny was more abrupt than previously suspected, and is consistent with the hypothesis that the orogeny involves a collision between two sialic plates.
Urea Cycle Enzyme Adaptation to Dietary Protein in Primates
Authors: Nuzum C. Thomas , Snodgrass Philip J.
Published: October 2006

Activities of the five hepatic enzymes of the urea cycle increased two- to threefold in monkeys on a 60 percent protein diet compared with levels in monkeys on an isocaloric 6 percent protein diet. Equal adaptation occurred in rats on the same diets. These enzyme activities in adult humans approximate those of monkeys on a similar protein intake.
Cucumber Beetle Resistance and Mite Susceptibility Controlled by the Bitter Gene in
Cucumis sativus
L.
Authors: Da Costa Cyro P. , Jones Charles M.
Published: October 2006

Antibiotic and nonpreference mechanisms are related in cucumber through the action of the
bi
gene and the absence of cucurbitacins. Cucurbitacins attract cucumber beetles and cause feeding whereas they have an antibiotic effect on two-spotted mites.
Diisopropylphosphorofluoridate and Tabun: Enzymatic Hydrolysis and Nerve Function
Authors: Hoskin Francis C. G.
Published: October 2006

Squid nerve contains an enzyme that hydrolyzes the nerve gas Tabun at about one-tenth the rate it hydrolyzes diisopropylphosphorofluoridate (DFP), and at about one-third to one-fourth the rate it hydrolyzes Sarin and Soman. Tabun is a more potent inhibitor of acetylcholinesterase than is DFP, is both lipid- and water-soluble, and penetrates readily into the squid giant axon in its inhibitory form. The failure of Tabun to block or markedly decrease the conducted action potential in the squid axon makes it likely that the blocking of conduction caused by DFP is probably not due to inhibition of acetylcholinesterase. Substrate specificity with regard to organophosphate metabolism by squid enzyme has possible implications for the disposal and detoxication of nerve gases in the ocean.
Leptospirosis Epizootic among California Sea Lions
Authors: Vedros Neylan A. , Smith Alvin W. , Schonewald Jacqueline , Migaki George , Hubbard Richard C.
Published: October 2006

A Leptospira species is suspected of being the etiological agent in a recent epizootic among California sea lions. The disease was confined to subadult males of the species
Zalophus c. californianus
.
Long-Term Improvement of Hypercholesterolemia After Ex Vivo Gene Therapy in LDLR-Deficient Rabbits
Authors: Chowdhury J. Roy , Grossman Mariann , Gupta Sanjeev , Chowdhury N. Roy , Baker James R. , Wilson James M.
Published: October 2006

Familial hypercholesterolemia (FH) is an inherited disorder in humans that is caused by a deficiency of low density lipoprotein receptors (LDLRs). An animal model for FH, the Watanabe Heritable Hyperlipidemic rabbit, was used to develop an approach for liver-directed gene therapy based on transplantation of autologous hepatocytes that were genetically corrected ex vivo with recombinant retroviruses. Animals transplanted with LDLR-transduced autologous hepatocytes demonstrated a 30 to 50 percent decrease in total serum cholesterol that persisted for the duration of the experiment (122 days). Recombinant-derived LDLR RNA was harvested from tissues with no diminution for up to 6.5 months after transplantation.
Alpha-Recoil Thorium-234: Dissolution into Water and the Uranium-234/Uranium-238 Disequilibrium in Nature
Authors: Kigoshi Kunihiko
Published: October 2006

The rate of ejection of alpha-recoil thorium-234 into solution from the surface of zircon sand gives an alpha-recoil range of 550 angstroms. The alpha-recoil thorium-234 atoms ejected into the groundwater may supply excess uranium-234. In pelagic sediments, ejected alpha-recoil thorium-234 may contribute to the supply of mobile uranium-234 in the sedimentary column.
Southern Corn Leaf Blight: Susceptible and Resistant Mitochondria
Authors: Miller Raymond J. , Koeppe David E.
Published: October 2006

Mitochondria isolated from etiolated shoots of blight-susceptible and blight-resistant corn plants were subjected, in various respiratory states, to the pathotoxin released by
Helminthosporium maydis
(race T). The addition of the pathotoxin to susceptible mitochondria caused respiratory rate and oxidative phosphorylation changes. The addition of pathotoxin to susceptible mitochondria suspended in a potassium chloride reaction medium induced an immediate and irreversible swelling regardless of the respiratory state of the mitochondria. This membrane swelling correlates with the observed respiratory and coupling effects of the pathotoxin. In all instances, mitochondria isolated from blight-resistant corn failed to exhibit any of the above responses to the pathotoxin.
Channelization: A Case Study
Authors: Emerson John W.
Published: October 2006

Channelization of the Blackwater River in Johnson County, Missouri, 60 years ago nearly doubled the gradient, which caused an increase in the rate of erosion for the river and its tributaries. Since the present channel is much wider and deeper than it was when newly dredged, there have been bridge repairs and loss of farmland. Downstream reduction in channel capacity due to termination of dredging has caused channel sedimentation and increased flooding.
Possible Prebiotic Condensation of Mononucleotides by Cyanamide
Authors: Ibanez J. D. , Kimball A. P. , Oró J.
Published: October 2006

The condensation of mononucleotides has been carried out in aqueous solution at neutral
p
H in the presence of cyanamide. Oligodeoxyribonucleotides up to five units have been formed when montmorillonite was present.
Calcium as a Mediator of Adrenocorticotrophic Hormone Action on Adrenal Protein Synthesis
Authors: Farese Robert V.
Published: October 2006

Calcium stimulates leucine incorporation into protein during incubations of sections and cell-free preparations of the rat adrenal. Like adrenocorticotrophic hormone (ACTH) action, calcium enhances the transfer of amino acid from transfer RNA to protein. Stimulation of leucine incorporation by ACTH and cyclic adenosine monophosphate is best observed when sections are incubated in limiting calcium concentrations.
DDT Administered to Neonatal Rats Induces Persistent Estrus Syndrome
Authors: Heinrichs W. L. , Gellert R. J. , Bakke J. L. , Lawrence N. L.
Published: October 2006

The
o
,
p
′-isomer of the insecticide DDT when injected into neonatal female rats significantly advanced puberty, induced persistent vaginal estrus after a period of normal estrous cycles, and caused the ovaries to develop follicular cysts and a reduced number of corpora lutea. The uterotropic response to administered estradiol was reduced, and the female pattern of mating behavior was slightly disturbed. Residues of DDT in ovarian, brain, and adipose tissues of the adult animals were the same in both treated and control groups.
Neuron Activity Related to Short-Term Memory
Authors: Fuster Joaquin M. , Alexander Garrett E.
Published: October 2006

Nerve cells in the monkey's prefrontal cortex and nucleus medialis dorsalis of the thalamus show changes of firing frequency associated with the performance of a delayed response test. Most cells increase firing during the cue presentation period or at the beginning of the ensuing delay; spike discharge higher than that in intertrial periods is present in some cells throughout the delay. These changes are interpreted as suggestive evidence of a role of frontothalamic circuits in the attentive process involved in short-term memory
Antarctic Bottom Water: Major Change in Velocity during the Late Cenozoic between Australia and Antarctica
Authors: Watkins N. D. , Kennett J. P.
Published: October 2006

Paleomagnetic and micropaleontological studies of deep-sea sedimentary cores between Australia and Antarctica define an extensive area centered in the south Tasman Basin, where sediment as old as Early Pliocene has been systematically eroded by bottom currents. This major sedimentary disconformity has been produced by a substantial increase in velocity of Antarctic bottom water, possibly associated with late Cenozoic climatic cooling and corresponding increased glaciation of Antarctica.
Fish Otoliths: Daily Growth Layers and Periodical Patterns
Authors: Pannella Giorgio
Published: October 2006

The early-stage annual rings in otoliths from some cold-temperate fish consist of thin growth bands, the number of which corresponds to that of the days in a year. This indicates that growth takes place by daily increments. Other recurrent patterns show a fortnightly and monthly periodicity. Spawning rings are microscopically distinguishable from winter rings.
Interstitial Silica and
p
H in Marine Sediments: Some Effects of Sampling Procedures
Authors: Fanning Kent A. , Pilson Michael E. Q.
Published: October 2006

The temperature at which the interstitial water was squeezed from a marine sediment had a profound effect on the measured interstitial silica concentrations which showed an average increase of 51 percent after the sediment was exposed to a temperature 20°C higher than the in situ temperature. Similar effects were not found for interstitial phosphate or alkalinity, but the
p
H was slightly higher in the water squeezed at the higher temperature. These temperature-induced changes were completed in a few hours. The use of filter paper can significantly lower the
p
H of expressed pore waters. Until some important questions about temperature effects are answered, all future data on the
p
H and silica concentration of pore waters of marine sediments should be obtained from samples extracted at in situ temperatures.
Axon Guidance by Gradients of a Target-Derived Component
Authors: Baier Herwig , Bonhoeffer Friedrich
Published: October 2006

Spatial gradients of axon guiding molecules have long been suspected to provide positional and directional cues for retinal ganglion cell axons growing within the optic tectum. With the identification of a guiding activity from tectal cell membranes, it has become possible to investigate the potential physiological significance of molecular gradients for retinal growth cone behavior in vitro. A subset of retinal growth cones, those from the temporal half, were highly sensitive to small concentration changes of the guiding component. The degree of response was correlated with the strength of the gradient. These findings demonstrate that the neural growth cone can read gradients of surface-associated information.
Agricultural Origins: Centers and Noncenters
Authors: Harlan Jack R.
Published: October 2006

I propose the theory that agriculture originated independently in three different areas and that, in each case, there was a system composed of a center of origin and a noncenter, in which activities of domestication were dispersed over a span of 5,000 to 10,000 kilometers. One system includes a definable Near East center and a noncenter in Africa; another system includes a North Chinese center and a noncenter in Southeast Asia and the South Pacific; the third system includes a Mesoamerican center and a South American noncenter. There are suggestions that, in each case, the center and noncenter interact with each other. Crops did not necessarily originate in centers (in any conventional concept of the term), nor did agriculture necessarily develop in a geographical "center."
Motions of Molecules in Liquids: Viscosity and Diffusivity
Authors: Hildebrand Joel H.
Published: October 2006

The fluidity of a simple liquid is proportional to its degree of expansion over the volume,
V
0
, at which its molecules are so crowded as to inhibit self-diffusion and viscous (as distinguished from plastic) flow. The equation of proportionality is 1/η = B[(
V
—
V
0
)/
V
0
] where η is the viscosity and
V
is the molal volume. Values of B are the same for normal paraffins from C
3
H
8
to C
7
H
16
and then decrease progressively as the paraffin lengths increase. Values for other liquids, C
6
H
6
, CCl
4
, P
4
, CS
2
, CHCl
3
, and Hg, appear to vary with repulsive forces. Liquids can be moderately fluid when expanded by less than 10 percent; this shows the unreality of some theoretical treatments of the liquid state. Diffusivity begins from the temperature at which
V
equals
V
0
and can be correlated for temperature dependence, and for solute-solvent interrelations.
Electron Microscopy and Diffraction of Layered, Superconducting Intercalation Complexes
Authors: Fernández-Morán H. , Ohstuki Mitsuio , Hibino Akemi , Hough Charles
Published: October 2006

Several layered, transition metal dichalcogenide intercalation complexes with unique superconducting properties have been examined by high-resolution electron microscopy and electron diffraction. Details of the crystalline lattice and of the lattice imperfections have been directly resolved. The results can be correlated with the available x-ray diffraction and chemical data, and they confirm and extend the postulated models.
Moonquakes
Authors: Latham G. , Ewing M. , Dorman J. , Lammlein D. , Press F. , Toksoz N. , Sutton G. , Duennebier F. , Nakamura Y.
Published: October 2006

Although the average rate of seismic energy release within the moon appears to be far below that of the earth, over 100 events believed to be moonquakes have been recorded by the two seismic stations installed on the lunar surface during Apollo missions 12 and 14. With few exceptions, the moonquakes occur at monthly intervals near times of perigee and apogee and show correlations with the longer-term (7-month) lunar gravity variations. The repeating moonquakes are believed to occur at not less than 10 different locations. However, a single focal zone accounts for 80 percent of the total seismic energy detected. This active zone appears to be 600 kilometers south-southwest of the Apollo 12 and 14 sites and deep within the moon. Each focal zone must be small (less than 10 kilometers in linear dimension) and fixed in location over a 14-month period. Cumulative strain at each location is inferred. Thus, the moonquakes appear to be releasing internal strain of unknown origin, the release being triggered by tidal stresses.
Magnetism and Local Molecular Field
Authors: Néel Louis
Published: October 2006

Despite its somewhat naive simplicity, the method of the local molecular field has had undeniable success in satisfactorily explaining a large number of previously known facts and in opening the way for the discovery of new facts. Let us note, however, that all the structures that have been discussed above are collinear structures: on the average (in time) all the atomic magnets pointing in one or the opposite direction are parallel to a single direction. However, the local molecular field method can also be extended to noncollinear structures such as that of helimagnetism, which Yoshimori and Villain discovered independently in an absolutely unexpected manner; one can thus interpret phenomena in a remarkably simple and concrete manner.

Nevertheless, the method can hardly be recommended for more complex structures such as the umbrella structure, which requires the decomposition of the principal crystal lattice into a large number of sublattices. Indeed, under these conditions an atom belonging to a given sublattice has only a very small number of neighbors (one or two) in each of the other sublattices, and the molecular field method, which consists in replacing the instantaneous action of an atom by that of an average atom, will be more likely to yield a correct result, the larger the number of atoms to which it is applied. Its correctness probably also increases as the atomic spin becomes larger. Independently of this problem, the method applied to a large number of sublattices completely loses its chief advantage, simplicity. The method also involves more insidious traps. If a judicious choice of parameters is made, the method can lead one to calculate curves and thermal variations of the spontaneous magnetization or paramagnetic susceptibility that coincide remarkably well with the experimental results, for example, to within a few thousandths. Under these conditions, one could expect that the elementary interaction energies deduced from these parameters would correspond to the actual values with the same accuracy. This is not so; errors of 10 to 20 percent and even greater are frequently made in this manner. A certain amount of caution thus becomes imperative.

On the other hand, recourse to the local molecular field seems indispensable since more rigorous methods lead to insurmountable complications. Consider for example that the rigorous solution is not yet known for the simplest case, that of a simple cubic lattice with identical atoms of spin 1/2, and interactions reduced to those present between nearest-neighbor atoms. How then should one treat the case of garnets with 160 atoms in the unit cell, spins up to 5/2, and at least six different coupling constants? One must therefore be lenient toward the imperfections of the molecular field methods, considering the simplicity with which the successes recalled in the first few lines of these conclusions were obtained.
Hypertension of Renal Origin: Evidence for Two Different Mechanisms
Authors: Brunner Hans R. , Kirshman J. Dianne , Sealey Jean E. , Laragh John H.
Published: October 2006

Antibody to angiotensin II, or a specific peptide competitive inhibitor of angiotensin II, was used to investigate the role of the renin-angiotensin system in two types of renal hypertension in rats. The data indicate that angiotensin II is in fact critically involved in the pathogenesis of the form of renal hypertension in which one renal artery is clamped and the contralateral kidney is left in place, but that it probably plays no significant role in the maintenance of experimental renal hypertension in which the opposite kidney has been removed.
Gene Selection in Hemoglobin and in Antibody-Synthesizing Cells
Authors: Kabat David
Published: October 2006

Close linkage of mutually exclusive genes occurs in the non-α chain hemoglobin genes and in the immunoglobulin genes of man and other mammals. The expression of one gene in the cluster precludes the expression of any other linked gene. A simple, testable theory of gene selection called "looping-out excision" which was designed only to explain this mutual exclusivity in the hemoglobin system is described. The theory is closely concordant with a wide range of previously unexplained findings concerning hematopoiesis—including the developmental changes of hemoglobins, the increases in immature or fetal forms of hemoglobin that accompany anemia, and with the distribution of adult and fetal hemoglobins among erythrocytes during normal embryogenesis and in various pathological conditions. One corollary of this theory is that erythroid tissue in the normal adult bone marrow is constantly recapitulating the developmental stages of its embryogenesis. Another corollary is that the selection from among the linked globin genes occurs independently on the two chromosomes of the diploid organism. Both of these corollaries are supported by the available data.

The same theory of gene selection is also remarkably consistent with known data for immunoglobulin synthesis; it could explain not only the mutually exclusive activation of linked variable genes but also the splicing which occurs between genetically linked variable and constant region genes for the immunoglobulin polypeptide chains. The agreement between these two different tissues is considered to be strong evidence that the proposed mechanism is correct at least in broad outline. Evidence from the genetics of maize and of drosophila also supports this theory of somatic tissue variegation. On the basis of these comparisons, I suggest that looping-out excision probably occurs also in other tissues and may be one means of gene selection and activation in differentiating cells.
Antibody-Dependent Lymphoid Cell-Mediated Cytotoxicity: No Requirement for Thymus-Derived Lymphocytes
Authors: van Boxel John A. , Stobo John D. , Paul William E. , Green Ira
Published: October 2006

The capacity of lymphoid cells from nonsensitized mice to lyse antibody-coated target erythrocytes in vitro does not require the presence of thymus-derived or thymus-dependent lymphocytes. Thus, spleen cells from thymus-deprived mice and spleen cell populations from which thymus-dependent lymphocytes had been removed were fully competent to mediate destruction of antibody-coated target cells. However, prior treatment of spleen cell populations with antibody to κ chains diminished this function, suggesting a role for bone marrow-derived lymphocytes.
Gamma-Aminobutyric Acid Antagonism and Presynaptic Inhibition in the Frog Spinal Cord
Authors: Davidoff Robert A.
Published: October 2006

The convulsant alkaloid bicuculline blocked presynaptic inhibition, dorsal root potentials, primary afferent depolarization, and depolarizing effects of gamma-aminobutyric acid on dorsal root terminals of the amphibian spinal cord, but did not block effects of other putative amino acid transmitters. These actions of bicuculline suggest that gamma-aminobutyric acid may be the transmitter involved in spinal presynaptic inhibition.
Geologic Setting of the Apollo 15 Samples
Authors:   Apollo Lunar Geology Investigation Team
Published: October 2006

The samples and photographs returned from the Apollo 15 site show that Hadley Delta is largely underlain by breccias whose clasts are mainly fragments of coarse-grained feldspathic rocks and nonmare-type basalt. Conspicuous sets of lineaments, visible in surface and orbital photographs of Mount Hadley and Hadley Delta, may represent systematic layering or fracture sets. The mare surface, with regolith about 5 meters thick, is underlain by two major basalt types, at least one of which has extensive lateral continuity and is exposed in the upper wall of Hadley Rille. Gradual erosional recession of the edges and filing of the interior of the rille by talus have contributed to the present cross sectional profile.
Microsomal Lipid Peroxidation: Morphological Characterization
Authors: Arstila A. U. , Smith Mary A. , Trump B. F.
Published: October 2006

Lipid peroxidation of liver and kidney microsomes induces a highly characteristic sequence of morphological changes typified by detachment of ribosomes and formation of large aggregates of vesicles bound together by dense amorphous material and myelin figure-like debris. The trilaminar structure of the membrane is, however, retained even after complete peroxidation, though its spacing may be increased. The aggregates resemble lysosomal lipofuscin pigment as well as the membranous aggregates of endoplasmic reticulum seen in the liver after carbon tetrachloride poisoning.
Aftershocks Caused by Pore Fluid Flow?
Authors: Nur Amos , Booker John R.
Published: October 2006

Large shallow earthquakes can induce changes in the fluid pore pressure that are comparable to stress drops on faults. The subsequent redistribution of pore pressure as a result of fluid flow slowly decreases the strength of rock and may result in delayed fracture. The agreement between computed rates of decay and observed rates of aftershock activity suggests that this is an attractive mechanism for aftershocks.
Biogenic Amine Metabolites in Cerebrospinal Fluid of Depressed and Manic Patients
Authors: Mendels J. , Frazer A. , Fitzgerald R. G. , Ramsey T. A. , Stokes J. W.
Published: October 2006

A reduction in 5-hydroxyindoleacetic acid in cerebrospinal fluid was found in depressed and manic patients both while they were symptomatic and also after treatment. The concentration of homovanillic acid was initially reduced and then tended to increase after treatment.
The Immune Reaction as a Stimulator of Tumor Growth
Authors: Prehn Richmond T.
Published: October 2006

Various numbers of spleen cells from specifically immunized mice were mixed with constant numbers of target tumor cells, and were inoculated subcutaneously into thymectomized, x-irradiated recipients. Small numbers of admixed immune spleen cells produced a statistically significant, and reproducible, acceleration of tumor growth in the inoculum as compared with controls of either nonimmune spleen cells or spleen cells from animals immune to a different, noncross-reacting, tumor. Larger numbers of specifically immune spleen cells, however, produced inhibition of tumor growth. These data imply that the normal immune reaction may have a dual function in relation to neoplasia: (i) stimulation of tumor growth, early in the course of the disease, or whenever the immune reaction is minimal; (ii) inhibition of tumor growth at other times.
Carbon Monoxide Balance in Nature
Authors: Weinstock Bernard , Niki Hiromi
Published: October 2006

Consideration of the steady-state equations for stable carbon monoxide and for radioactive carbon monoxide in the troposphere leads to the conclusion that carbon monoxide is produced at a rate of 5 × 10
15
grams per year, a value some 25 times greater than the rate of carbon monoxide production from combustion. The concomitant residence time for carbon monoxide is 0.1 year, in agreement with a previous estimate of Weinstock. Hydroxyl radicals are shown to account for both the production of this large amount of carbon monoxide by methane oxidation and for its removal by carbon monoxide oxidation. The average concentration of hydroxyl radicals in the troposphere required to achieve this effect is 2.3 × 10
6
molecules per cubic centimeter, with a daytime concentration of twice that. Levy and McConnell, McElroy, and Wofsy have deduced concentrations of hydroxyl radicals in the troposphere of the same magnitude from purely photochemical considerations, in support of this model.
Electrical Field-Flow Fractionation of Proteins
Authors: Caldwell Karin Dahlgren , Kesner Laya Floch , Myers Marcus N. , Giddings J. Calvin
Published: October 2006

Protein separation has been achieved by electrical field-flow fractionation, a heretofore unrealized separation technique. Some advantages of this method relative to electrophoresis are the low voltage required, the lack of adverse heating and support effects, and the existence of the method as an elution technique. A comparison of theoretical and experimental retention shows good agreement.
Hepatic Collagen Metabolism: Effect of Alcohol Consumption in Rats and Baboons
Authors: Feinman Lawrence , Lieber Charles S.
Published: October 2006

Long-term ethanol feeding causes collagen accumulation in livers of rats and baboons. Activity of collagen proline hydroxylase in the liver is also stimulated, and incorporation of proline into collagen hydroxyproline in rat liver slices is significantly enhanced, a result indicating that increased synthesis is responsible, in part, for the collagen accumulation.
Environmental Applications of the Weibull Distribution Function: Oil Pollution
Authors: Mikolaj Paul G.
Published: October 2006

The Weibull distribution function appears to be a powerful tool for the statistical analysis and interpretation of environmental pollution data. To illustrate its potential, the method is applied to a variety of oil pollution topics. Other applications are suggested.
Reversion of Murine Sarcoma Virus Transformed Mouse Cells: Variants without a Rescuable Sarcoma Virus
Authors: Fischinger P. J. , Nomura S. , Peebles P. T. , Haapala D. K. , Bassin R. H.
Published: October 2006

Murine sarcoma virus transformed mouse 3T3 cells, which are negative for murine leukemia virus and which yield sarcoma virus after superinfection with murine leukemia virus, spontaneously give rise to flat variants from which murine sarcoma virus can no longer be rescued. The revertants support leukemia virus growth and show an enhanced sensitivity to murine sarcoma superinfection and, like normal cells, do not release RNA-dependent DNA polymerase activity. Because revertants could be obtained with high frequency from progeny of single transformed cells, each cell that contains the sarcoma virus genome seems to have the capacity to suppress or eliminate an RNA tumor virus native to its species of origin.
Oceanic Electric Fields: Perception by American Eels?
Authors: Rommel S. A. , McCleave J. D.
Published: October 2006

American eels, long-distance migrating fish, consistently exhibited conditioned cardiac deceleration responses to electric fields as small as 0.167 × 10
-2
microampere per square centimeter in water of resistivity 4000 ohm centimeters (6.7 microvolts per centimeter) and 400 ohm centimeters (0.67 microvolt per centimeter). Fewer responses were shown at this current density (0.167 × 10
-2
microampere per square centimeter) in more saline water (40 ohm centimeters, 0.067 microvolt per centimeter) and at a lower current density (0.167 × 10
-3
microampere per square centimeter) in fresh water. Thus, eels have sufficient sensitivity to utilize geoelectric information for orientation.
Interferon Administered Orally: Protection of Neonatal Mice from Lethal Virus Challenge
Authors: Schafer Thomas W. , Lieberman Melvin , Cohen Mildred , Came Paul E.
Published: October 2006

Interferon was identified in the milk of mice injected with an interferon inducer. The kinetics of interferon appearance in serum and in milk were similar, but maximum concentrations in milk were 10 to 20 percent of those in serum. Interferon administered orally to neonatal mice was detected in their serums. Significantly more newborns survived an oral challenge with vesicular stomatitis virus when interferon had been induced in the lactating mothers.
Inhibition of HIV Replication in Acute and Chronic Infections in Vitro by a Tat Antagonist
Authors: Hsu Ming-Chu , Schutt Andrew D. , Holly Maureen , Slice Lee W. , Sherman Michael I. , Richman Douglas D. , Potash Mary Jane , Volsky David J.
Published: October 2006

The human immunodeficiency virus-1 (HIV-1) trans-activator Tat is an attractive target for the development of antiviral drugs because inhibition of Tat would arrest the virus at an early stage. The drug Ro 5-3335 [7-chloro-5-(2-pyrryl)-3
H
-1,4-benzodiazepine-2(
H
)-one], inhibited gene expression by HIV-1 at the level of transcriptional trans-activation by Tat. The compound did not inhibit the basal activity of the promoter. Both Tat and its target sequence TAR were required for the observed inhibitory activity. Ro 5-3335 reduced the amount of cell-associated viral RNA and antigen in acutely, as well as in chronically infected cells in vitro (median inhibition concentration 0.1 to 1 micromolar). Effective inhibition of viral replication was also observed 24 hours after cells were transfected with infectious recombinant HIV-1 DNA. The compound was active against both HIV-1 and HIV-2 and against 3′-azido-3′-deoxythymidine (AZT)-resistant clinical isolates.
Birch's Law: Why Is It So Good?
Authors: Chung Dae H.
Published: October 2006

Birch's law arises in the physics of solids as a linear approximation, in a certain range of density, of a power law. For a change of chemical composition within the same crystal structure, the velocity-density relation is constant with a slope of nearly -0.5 in the first-order approximation.