bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein Synthesis: Its Control in Erythropoiesis
Authors: Marks Paul A. , Rifkind Richard A.
Published: October 2006

Erythropoiesis in the fetal mouse provides a model to study several important aspects of the regulation of cell differentiation and differentiated protein synthesis. Changes in the patterns of hemoglobins formed during fetal and postfetal development are shown to be associated with the substitution of the liver erythroid cell line. In the course of differentiation of yolk sac erythroid cells there are at least two classes of proteins distinguishable with respect to dependence on continued RNA formation. The bulk of nuclear proteins, "nondifferentiated" proteins, appear to be dependent on relatively short-lived messenger RNA while synthesis of differentiated proteins, the hemoglobins, proceeds on relatively stable molecules of messenger RNA. Hemoglobin formation occurs in those cells which are actively synthesizing DNA and dividing. On the average, two to three cell divisions may occur after the formation and stabilization of the messenger RNA for globin. Yolk sac erythropoiesis, at least from day 10 of gestation, is unresponsive to erythropoietin. By comparison, in fetal liver erythropoiesis, the hormone, erythropoietin, acts selectively on the most immature erythroid cell precursor to induce differentiation, cell replication, and hemoglobin formation. The erythropoietin responsive cell in the liver is apparently differentiated from the progenitor, pluripotential stem cell and committed to erythroblast formation and hemoglobin synthesis on exposure to the hormone. The initial effects of erythropoietin on macromolecular synthesis are to stimulate RNA synthesis, which temporally is followed by cell replication and the increase in hemoglobin formation. During liver erythropoiesis, there appears to be a transition from hemoglobin synthesis dependent on RNA formation to hemoglobin synthesis directed by relatively stable messenger RNA.
Infrared Spectral Emittance in Geological Mapping: Airborne Spectrometer Data from Pisgah Crater, California
Authors: Lyon R. J. P.
Published: October 2006

Measurements of spectral emittance in the infrared region from 6.8 to 13.3 micrometers were made with an airborne spectrometer at a rate of six spectra per second, on flights 650 meters above the olivine basalt flows at Pisgah Crater in the southern Californian desert. The spectra show chemical and mineralogical differences that can be related to differences in the terrain below the aircraft.
Rock-Type Discrimination from Ratioed Infrared Scanner Images of Pisgah Crater, California
Authors: Vincent Robert K. , Thomson Frederick J.
Published: October 2006

The radiances in two thermal infrared channels of an airborne scanner system were ratioed to produce images that recorded compositionally diagnostic emittance variations for several silicate rock types near Pisgah Crater, California.
Cilia: Activation Coupled to Mechanical Stimulation by Calcium Influx
Authors: Murakami Akira , Eckert Roger
Published: October 2006

Ciliated epithelial cells in the oviduct of
Necturus maculosus
were stimulated mechanically by brief dimpling with a microstylus. This treatment produced a transient depolarization of the membrane, and a transient increase in the frequency of ciliary beating. The increase in frequency of ciliary beating was related to the concentration of extracellular calcium ion, decreasing with reduction in calcium. Addition of lanthanum was followed by a decrease in spontaneous ciliary activity and a hyperpolarization of the membrane. In the presence of lanthanum, the transient depolarization in response to mechanical stimulation had a shorter time course, and the concomitant increase in ciliary frequency was greatly reduced. It is concluded that calcium ions enter the cell as a result of mechanical stimulation of the membrane, and that calcium influx leads to an increase in the frequency of ciliary activity.
Vesicular Stomatitis Virus (Indiana Serotype): Transovarial Transmission by Phlebotomine Sandflies
Authors: Tesh Robert B. , Chaniotis Byron N. , Johnson Karl M.
Published: October 2006

Transovarial transmission of vesicular stomatitis virus (Indiana serotype) by experimentally infected
Lutzomyia trapidoi
and
Lutzomyia ylephiletrix
to their progeny was demonstrated. Virus was recovered from all developmental stages; mean virus titers from egg to first generation adult showed a four-log increase, indicating that virus multiplication occurred during development of the sandflies. Virus titers in first generation adult females were comparable to those found in their parents. These infected female sandflies transmitted vesicular stomatitus virus Indiana by bite to susceptible animals and transmitted the virus transovarially to their offspring (second generation). Results demonstrate a possible mechanism for transmission and maintenance of this virus in nature without a vertebrate (heat) host reservoir.
Norepinephrine and Dopamine: Assay by Mass Fragmentography in the Picomole Range
Authors: Koslow S. H. , Cattabeni F. , Costa E.
Published: October 2006

Gas chromatography-mass spectrometry makes possible the simultaneous measurement of norepinephrine and dopamine in concentrations of 0.1-milligram tissue samples. Specificity of the assay is confirmed both by the retention time of the compound and by the mass to charge ratio of the fragments recorded. The sensitivity is of the order of 0.5 picomole, and linearity of the response is maintained up to at least 200 picomoles.
A Calcium Pump in Vascular Smooth Muscle
Authors: Fitzpatrick David F. , Landon Erwin J. , Debbas Gamil , Hurwitz Leon
Published: October 2006

A microsomal cell fraction derived from the intimal-medial layer of rabbit aorta takes up calcium in the presence of magnesium and adenosine triphosphate. The rate of uptake of calcium is slower than that observed in skeletal muscle microsomes. Uptake of calcium by mitochondria from the aorta is even more limited and, unlike microsomal uptake, is inhibited by azide.
Pollution Monitor for Nitric Oxide: A Laser Device Based on the Zeeman Modulation of Absorption
Authors: Kaldor Andrew , Olson Wm. Bruce , Maki Arthur G.
Published: October 2006

The concentration of nitric oxide can be monitored by a new device in which the Zeeman effect is used to shift an absorption line of nitric oxide into coincidence with a laser line of carbon monoxide. The absorption is modulated by a small, oscillating magnetic field. This device is specific for nitric oxide and is not subject to interference from other gases.
Oil Pollution: Persistence and Degradation of Spilled Fuel Oil
Authors: Blumer Max , Sass Jeremy
Published: October 2006

In September 1969, approximately 600 metric tons of number 2 fuel oil were spilled in Buzzards Bay, Massachusetts. Two years later, fuel oil hydrocarbons still persisted in the marsh and in offshore sediments. Hydrocarbon degradation is slow, especially below the immediate sediment surface and appears to proceed principally through microbial utilization of alkanes and through partial dissolution of the lower-boiling aromatic hydrocarbons. The boiling range of the spilled oil and the relative abundances of homologous hydrocarbons (for example, phytane and pristane) have been well preserved. The findings are in agreement with the known geochemical stability of hydrocarbons. Fuel oil is an appreciable fraction of whole crude oil. This fact suggests that oil products and crude oils have a considerable environmental persistence.
Somatic Cell Genetic Assignment of Peptidase C and the Rh Linkage Group to Chromosome A-1 in Man
Authors: Ruddle F. , Ricciuti F. , McMorris F. A. , Tischfield J. , Creagan R. , Darlington G. , Chen T.
Published: October 2006

The segregation of the human peptidase-C phenotype in five different series of human-mouse hybrid clones was examined. The chromosome constitution of these hybrids was determined by quinacrine mustard fluorescence, Giemsa banding, and constitutive heterochromatin staining. That the clones could be classified without exception either as human peptidase C positive/ A-1 positive (14 clones), or as peptidase C negative/ A-1 negative (12 clones) indicates that peptidase C can be assigned to the human A-1 chromosome. Data from an extensive series of human-mouse clones used provide support for the syntenic association between peptidase C and phosphoglucomutase-1 and by inference a linkage of both to Rh factor group.
Calcium and Sodium Contributions to Regenerative Responses in the Embryonic Excitable Cell Membrane
Authors: Miyazaki Shun-Ichi , Takahashi Kunitaro , Tsuda Kazuko
Published: October 2006

Ionic dependence of regenerative responses of the embryonic cell membrane has been studied successively at each stage of development from the unfertilized egg to the differentiated striated muscle in the tadpole larva of the tunicate. The unfertilized egg cell itself showed a type of regenerative response dependent on both sodium and calcium ions, while the spike potentials exclusively dependent on calcium ions were elicited in the differentiated muscle cell.
Yellow Fever Vaccination, Avian Leukosis Virus, and Cancer Risk in Man
Authors: Waters Tommy D. , Anderson Paul S. , Beebe Gilbert W. , Miller Robert W.
Published: October 2006

Comparison was made between 2659 veterans who died of cancer, during 1950 to 1954 or 1959 to 1963, and matched controls, based on the frequency of yellow fever immunization during World War II. The vaccine was produced from chick embryos that almost certainly contained avian leukosis-sarcoma viruses. Among the veterans, no relation was found between vaccination and leukemia, lymphoma, or other cancer.
Telecommunications with Muon Beams
Authors: Arnold Richard C.
Published: October 2006

The properties of well-collimated beams of muons with energies in the range of 10
9
electron volts may be suited to some specialized needs in telecommunications. A demonstration of muon telecommunications has been carried out at Argonne National Laboratory.
Crustacean Color-Change Hormone: Amino Acid Sequence and Chemical Synthesis
Authors: Fernlund Per , Josefsson Lars
Published: October 2006

The blanching hormone of the prawn,
Pandalus borealis
, is pGlu-Leu-Asn-Phe-Ser-Pro-Gly-Trp-NH
2
. Its structure was settled by a combination of mass spectrometry and Edman-dansyl analysis of a thermolysin fragment. Confirmation of the structure was obtained by chemical synthesis from amino acids. This neurosecreted hormone is active in picogram amounts when tested in shrimps.
Photoreception in a Barnacle: Electrophysiology of the Shadow Reflex Pathway in
Balanus cariosus
Authors: Millecchia Ronald , Gwilliam G. Frank
Published: October 2006

The photoreceptors in the median ocellus of the rock barnacle depolarize when illuminated. This depolarization spreads passively to the axon terminals in the supraesophageal ganglion. A small number of cells in the supraesophageal ganglion hyperpolarize when the median ocellus is illuminated and depolarize when it is shadowed. Nerve impulses are superimposed on the slow depolarization of the ganglion cells. Impulse activity in response to shadowing the median ocellus is recorded in a few fibers of the circumesophageal connectives. Picrotoxin blocks this shadow-induced activity. A model of the shadow reflex pathway is presented.
Particulate Bioluminescence in Dinoflagellates: Dissociation and Partial Reconstitution
Authors: Fuller C. W. , Kreiss Paul , Seliger H. H.
Published: October 2006

With the same extraction conditions used for
Gonyaulax polyedra
, soluble and particulate bioluminescence can be isolated from two additional species,
Pyrodinium bahamense
and
Pyrocystis lunula
. We have been able, for all three species, to dissociate soluble luciferin and luciferase from the particulate system. Luciferin can be incorporated into both reacted and unreacted particulate systems.
Acetylcholine Responses in L Cells
Authors: Nelson Phillip G. , Peacock John H.
Published: October 2006

L cells, a family of continuous cell lines of mouse fibroblastic origin, generate a prolonged active membrane hyperpolarization (the hyperpolarizing activation response) when stimulated mechanically or electrically. Iontophoretically applied acetylcholine elicits a similar response; atropine blocks the acetylcholine but not the electrically or mechanically elicited responses. The hyperpolarizing activation response can also be elicited by electrical, mechanical, or acetylcholine stimulation of cells adjacent to the recorded cell. Propagation of the response from one cell to another is not dependent on direct electrical coupling between cells and is not blocked by application of a bath containing atropine or curare. These results show that L cells are capable of generating an active electrical response. that they are sensitive to at least one neurotransmitter (acetylcholine), and that humorally mediated interaction (probably noncholinergic) between L cells occurs.
Axotomy Mimicked by Localized Colchicine Application
Authors: Pilar Guillermo , Landmesser Lynn
Published: October 2006

Comparable depression of synaptic transmission in the avian ciliary ganglion resulted from either section or localized colchicine treatment of the ciliary nerves. Both colchicine treatment and axotomy produced similar changes in RNA distribution in the cell bodies as well. Colchicine did not directly affect transmission, and action potential propagation along the ciliary nerves was normal. Interference with axoplasmic transport of material in both cases is postulated to signal the observed chromatolytic changes.
Water Pollution: Organic Compounds in the Charles River, Boston
Authors: Hites Ronald A. , Biemann K.
Published: October 2006

The major lipophilic organic compounds present in water collected during November and December 1971 from the Charles River Basin (Boston) are as follows: normal alkanes (C
15
to C
31
), alkyl naphthalenes, alkyl anthracenes or phenanthrenes, pyrene, fluoranthene, dibutyl phthalate, and di(2-ethylhexyl) phthalate. The concentration of the naphthalenes (determined by liquid chromatography) correlates with the effective storm-water runoff content of the river. These data suggest a multiplicity of sources ranging from indigenous biological materials to automobile exhaust condensate.
Adenosine 3′,5′-Monophosphate: Electrophysiological Evidence for a Role in Synaptic Transmission
Authors: McAfee Donald A. , Greengard Paul
Published: October 2006

Synaptic potentials and changes in resting membrane potentials of superior cervical ganglia of the rabbit were measured in the presence of adenosine 3′5′-monophosphate and agents that affect its metabolism. Adenosine 3′5′-monophosphate and its mono- and dibutyryl derivatives caused a hyperpolarization of the postganglionic neurons. Theophylline potentiated the slow inhibitory postsynaptic potential that follows synaptic transmission, as well as the hyperpolarization of postganglionic neurons caused by exogenous dopamine. Conversely, prostaglandin E
1
inhibited both the slow inhibitory postsynaptic potential and the dopamine-induced hyperpolarization. We hypothesize that the slow inhibitory postsynaptic potential as well as the dopamine-induced hyperpolarization result from increased amounts of adenosine 3′5′-monophosphate in the postganglionic neurons. The dibutyryl derivative of guanosine 3′5′-monophosphate caused a depolarization of the postganglionic neurons, which is consistent with the possibility that guanosine 3′5′-monophosphate mediates synaptic transmission at muscarinic cholinergic synapses.
The Size of Suspended Particulate Matter in Air
Authors: Lee Robert E.
Published: October 2006

By means of the NASN cascade impactor the particle sizes of ambient aerosols can be measured by fractionating the particles according to their aerodynamic dimensions, and the fractions can be quantified gravimetrically. Data obtained with this instrument show that particulate matter suspended in urban air in the United States and Great Britain is remarkably uniform in distribution and that the particles are predominantly less than 1 μm in diameter. In Ankara, Turkey, the high proportion of particles larger than 1 μm in diameter are associated with the incomplete combustion of lignite; particulate concentrations in Ankara, however, are considerably higher than those measured elsewhere. The growth of particles in air during temperature inversions occurs in Cincinnati; the greater proportion of large particles found there during inversion periods can account for the reduction in visibility. Aerosols in the vicinity of highways are composed of particles larger than those found some distance away because of the reentrainment of debris by the traffic-induced turbulence. On the other hand, highway configuration and traffic volume have little effect on the size distribution of aerosols in samples collected away from the turbulence area of the roadway. Aerosols measured inside buildings are predominantly smaller in size and exhibit a narrower range of sizes than aerosols outside buildings.
Mercury Concentrations in Recent and Ninety-Year-Old Benthopelagic Fish
Authors: Barber Richard T. , Vijayakumar Aiyasami , Cross Ford A.
Published: October 2006

Several species of bottom-dwelling fish from 2500 meters with similar feeding habits had mercury concentrations that differed by an order of magnitude. Within one species there was a correlation between size and concentration, with the larger individuals having mercury concentrations as high as 0.8 part per million (wet weight). The mercury content of the water in the deep-ocean habitat of these fish appears not to determine the mercury content of a particular fish; species-specific factors and size do appear to determine this concentration. The species-specific variation between the recent fish also existed between the same two species in specimens collected 90 years ago from a depth of 2000 meters, and a 90-year-old specimen fit closely the size-concentration regression curve for nine recent individuals of the same species.
Fever: Reciprocal Shift in Brain Sodium to Calcium Ratio as the Set-Point Temperature Rises
Authors: Myers R. D. , Tytell M.
Published: October 2006

A bacterial pyrogen acts on the brain by disturbing the natural balance between two essential cations in the cerebral region involved in thermoregulation. After typhoid vaccine is administered to the unanesthetized cat,
45
Ca
2+
efflux into the third cerebral ventricle increases while
22
Na
+
is retained in hypothalamic tissue at the same time that the set-point temperature begins to rise. The subsequent rates of
22
Na
+
and
45
Ca
2+
efflux parallel the course of the bacterial fever but in a reciprocal fashion. This supports the theory that a change in the set-point temperature is determined by an alteration in the inherent ratio of Na
+
to Ca
2+
ions in the hypothalamus.
Mössbauer Spectroscopy: Recent Developments
Authors: Cohen R. L.
Published: October 2006

In this review I have emphasized two basic points. First, Mössbauer spectroscopy has been widely used as a tool for basic research in solid-state physics, chemical structure, and magnetism. Second, the technique has been applied to many analytical and materials science problems where the nature of the sample prevents the use of more traditional approaches. Mössbauer spectroscopy research on frozen solutions, colloids, interface chemistry, and crystallographic transformations can be expected to increase rapidly in the next few years.
Temperature Regulation by the Inflorescence of Philodendron
Authors: Nagy Kenneth A. , Odell Daniel K. , Seymour Roger S.
Published: October 2006

The inflorescence of
Philodendron selloum
temporarily maintains a core temperature of 38° to 46°C, despite air temperatures ranging from 4° to 39°C, by means of a variable metabolic rate. The heat is produced primarily by small, sterile male flowers that are capable of consuming oxygen at rates approaching those of flying hummingbirds and sphinx moths.
Reversed Development and Cellular Aging in an Insect
Authors: Beck Stanley D. , Bharadwaj R. K.
Published: October 2006

Larvae of the beetle
Trogoderma glabrum
undergo partially reversed development when deprived of food and water. Retrogressive larval ecdyses occur, and the larvae become diminished in size and weight. Given food, the larvae regrow, ecdyze, and regain their previous degree of maturity. Repeated cycles of retrogression and regrowth are possible. Although larval in form and organ differentiation, repeatedly retrogressed insects display a physiological deterioration suggestive of aging. A deterioration of the ability to regrow is accompanied by increasing fat body polyploidy.
The Revolution in Birth Control Practices of U.S. Roman Catholics
Authors: Westoff Charles F. , Bumpass Larry
Published: October 2006

There has been a wide and increasing defection of Roman Catholic women from the traditional teaching of their Church on the subject of birth control over the past two decades and a resulting convergence of Catholic and non-Catholic contraceptive practices. By 1970, two-thirds of all Catholic women were using methods disapproved by their Church; this figure reached three-quarters for women under age 30. Considering the fact that most of the one-quarter of young Catholic women conforming to Church teaching had never used any method, the percentage of those deviating may well reach 90 as these women grow older and the problems of fertility control become more important.

Much of this increasing deviation has been among the more educated Catholics, who were formerly the most faithful adherents to Church teaching. The change between 1965 and 1970 was especially striking for Catholic women who had attended college.

Perhaps the most significant finding is that the defection has been most pronounced among the women who receive Communion at least once a month. Even among this group, the majority now deviates from Church teaching on birth control; among the younger women in this group, the proportion not conforming reaches two-thirds.

It seems abundantly clear that U.S. Catholics have rejected the 1968 papal encyclical's statement on birth control and that there exists a wide gulf between the behavior of most Catholic women, on the one hand, and the position of the more conservative clergy and the official stand of the Church itself, on the other. That many Catholics can continue in their other religious practices and simultaneously deviate on the issue of birth control is an interesting commentary on the process of social change.

Ultimately this crisis of authority will probably be resolved by a change in official teaching, since it seems doubtful that such a major discrepancy can continue indefinitely without other repercussions. At a minimum, the cost to the Roman Catholic Church will be a loss of authority in a major area of life: that of sex and reproduction.
Early Cultivated Beans (
Phaseolus vulgaris
) from an Intermontane Peruvian Valley
Authors: Kaplan L. , Lynch Thomas F. , Smith C. E.
Published: October 2006

Examples of fully domesticated common beans (
Phaseolus vulgaris
) and lima beans (
Phaseolus lunatus
) were recovered from deposits in Guitarrero Cave (PAn 14-102) in the Callejón de Huaylas, Ancash, Peru. Carbon-14 dates for stratum II, in which the earliest beans were found, range from 7,680 ± 280 to 10,000 ± 300 years before the present.
Paleozoic Seeds with Embryos
Authors: Miller C. N. , Brown J. T.
Published: October 2006

Seeds in a conifer cone from the Lower Permian of west Texas contain embryo tissue. These are the oldest plant embryos on record. Their development prior to seed dispersal shows that the sequence of embryo growth typical of most modern seed plants had evolved before the end of the Paleozoic Era.
Earliest Radiocarbon Dates for Domesticated Animals
Authors: Protsch Reiner , Berger Rainer
Published: October 2006

Our dates show that cattle and pigs were first domesticated in Europe. Sheep, which were thought to have become extinct in Europe during the terminal Pleistocene, also appear first in Europe. However, there remains little doubt that sheep were first domesticated in the Near East or Turkey, since no wild sheep appear to have existed in Europe at the beginning of the Holocene. Dogs were domesticated in both the Near East and Europe at virtually the same time. In the Near East, Asiab, at around 8000 B.C., qualifies as the first center of goat domestication. It is also the earliest center of domestication for all animals we have dated here. Horses were first domesticated in the steppes of the Ukraine, perhaps even earlier than our dates indicate, since all of the samples found at Polling are virtually contemporaneous (Fig. 1).

Undoubtedly, future research will alter the details of our overall impressions, especially after bones at earlier sites such as Nea Nikomedeia have been dated directly. But, on balance, there can be no doubt that southeastern Europe was as much an early center of domestication as the Near East was.
Fine Structure of Muscle Cells of the Human Testicular Capsule: Basis of Testicular Contractions
Authors: Langford George A. , Heller Carl G.
Published: October 2006

Electron micrographs of human testicular capsule reveal large numbers of branching smooth muscle cells coursing through collagenous tissue of the tunica albuginea. These cells have subcellular morphology characteristic of smooth muscle cells, and they associate with one another through areas of close contact. These are the contractile cells responsible for spontaneous contractions of the human testicular capsule—contractions that may be important in transporting nonmotile sperm out of the testis.
Oncogenic Transformation of Human Embryo Lung Cells by Human Cytomegalovirus
Authors: Geder Laszlo , Lausch Robert , O'Neill Frank , Rapp Fred
Published: October 2006

Persistent infection of human embryo lung fibroblasts with a genital isolate of cytomegalovirus resulted in oncogenic transformation of these cells. Immunofluorescence techniques detected virus-specific antigens, while microcytotoxicity tests established that the transformed cells share a membrane antigen with hamster cells transformed by inactivated cytomegalovirus. The transformed human cells induced progressively growing tumors in weanling athymic nude mice.
Blood Cells Preserved in a Mummy 2000 Years Old
Authors: Zimmerman Michael R.
Published: October 2006

Structures resembling red blood cells have been seen in mummies, but have been considered by some to be artifacts or molds. The finding of these structures, admixed with white blood cells, in the blood vessels of a mummified American Indian, confirms the original interpretation of preserved red blood cells.
Complement-Induced Platelet Protein Alterations
Authors: Zimmerman Theodore S. , Müller-Eberhard Hans J.
Published: October 2006

Polypeptides of high molecular weight are deleted from the sedimentable fraction of platelets subjected, while intact, to complement action. These polypeptides, distinct from the previously described thrombin-sensitive protein of this fraction, also diminish after platelets are exposed to thrombin. They may be of importance in the molecular events underlying complement-triggered changes in platelet function.
Temperature-Sensitive Pawns: Conditional Behavioral Mutants of
Paramecium aurelia
Authors: Chang Sheng-Yung , Kung Ching
Published: October 2006

"Pawns" are mutants of
Paramecium aurelia
in which the process of calcium activation during membrane excitation is genetically impaired, with a corresponding loss of avoiding reactions. Mutants are selected that behave normally when grown at 23°C but as pawns at 35°C. The normal excitation can now be disrupted and restored in the same strain at will.
Postlesion Axonal Growth Produces Permanent Functional Connections
Authors: Lynch Gary , Deadwyler Sam , Cotman Carl
Published: October 2006

Lesions of the entorhinal cortex in neonatal rats cause the commissural projections to the dentate gyrus to spread from their normal location in the inner molecular layer into the outer molecular layer, a region normally occupied by afferents from the entorhinal cortex. These lesions also cause the short-latency response to commissural stimulation to spread into the outer molecular layer, a result suggesting that these abnormally located connections are operative.
New Seismic Data on the State of the Deep Lunar Interior
Authors: Nakamura Y. , Lammlein D. , Latham G. , Ewing M. , Dorman J. , Press F. , Toksöz N.
Published: October 2006

Direct shear-wave arrivals from seismic events originating on the far side of the moon are not observed at some of the stations of the Apollo seismic network. These data suggest that the material in the lunar interior at a depth of 1000 to 1100 kilometers is more dissipative for seismic shear waves than the lithosphere above, and possibly exists in a partially molten state akin to the earth's asthenosphere.
The Economics of Overexploitation
Authors: Clark Colin W.
Published: October 2006

The general economic analysis of a biological resource presented in this article suggests that overexploitation in the physical sense of reduced productivity may result from not one, but two social conditions: common-property competitive exploitation on the one hand, and private-property maximization of profits on the other. For populations that are economically valuable but possess low reproductive capacities, either condition may lead even to the extinction of the population. In view of the likelihood of private firms adopting high rates of discount, the conservation of renewable resources would appear to require continual public surveillance and control of the physical yield and the condition of the stocks.
Phototaxis and Sensory Transduction in
Euglena
Authors: Diehn Bodo
Published: October 2006

The accumulation of
Euglena gracilis
in an illuminated region is brought about by two main mechanisms: orientation and subsequent directed movement (positive phototaxis) toward light scattered from particles in the illuminated zone; and by the trapping of cells in this region because of shock reactions experienced upon the cells encountering a sudden decrease of light intensity at the light-dark boundary (inverse photophobic responses). Phototactic orientation is mediated by inverse photophobic reactions which occur when the shadow of the stigma periodically falls upon the photoreceptor proper.
Euglena
also exhibits shock reactions when an already high light intensity is increased further (direct photophobic responses).

The expression of both types of phobic responses depends upon stimulus intensity and adaptation of the sensory system in a seemingly complex way. A definition of the minimum components of the stimulus transduction system and a systems analytical approach to the study of input-output relationships enables one to construct an electronic analog of the cell's signal processing system that converts the photoreceptor input to commands which activate or inhibit flagellar reorientation. Computer simulation studies show that this model has considerable predictive value.

It is hoped that with the approach presented in this article, a generalized model has become available for dealing with the questions of sensory transduction in aneural systems. Certainly, at this point more questions have been raised than have been answered. Where is the processing device located? Are its kinetic properties determined by electrical processes or by the rates of chemical reactions? Is the processor, and thereby the behavior of the organism, modulated by natural environmental parameters, and can it be modified permanently through more drastic chemical treatment of the cell? Is the system capable of permanent or transitory modification through repeated response, that is, does it exhibit phenomena analogous to learning and memory in higher organisms? These are only a few of the problems that require study in the future.
Overeating and Obesity from Damage to a Noradrenergic System in the Brain
Authors: Ahlskog J. Eric , Hoebel Bartley G.
Published: October 2006

A discrete, ascending fiber system that supplies the hypothalamus with most of its noradrenergic terminals was destroyed at midbrain level, both electrolytically and with local injections of 6-hydroxydopamine, a destructive agent specific for catecholaminergic neurons. The result was hyperphagia leading to obesity. Fluorescence histochemical analysis showed that loss of noradrenergic terminals in ventral bundle termination areas such as the hypothalamus was necessary for hyperphagia. Damage to dorsal bundle or dopaminergic projections was not. Prior treatment with desmethylimipramine to selectively block uptake of 6-hydroxydopamine into noradrenergic neurons prevented both hyperphagia and loss of norepinephrine fluorescence. The lesions that produced hyperphagia also reduced the potency of
d
-amphetamine as an appetite suppressant. It is concluded that this noradrenergic bundle normally mediates suppression of feeding, thereby influences body weight, and serves as a substrate for
d
-amphetamine-induced loss of appetite.
Hypothalamic Obesity: The Myth of the Ventromedial Nucleus
Authors: Gold Richard M.
Published: October 2006

Lesions restricted to the ventromedial nucleus of the hypothalamus were neither necessary nor sufficient for, and did not contribute to, the production of hypothalamic obesity. Hypothalamic lesions and knife cuts that do produce obesity damage the nearby ventral noradrenergic bundle or its terminals.
Functional Organelles in Prokaryotes: Polyhedral Inclusions (Carboxysomes) of
Thiobacillus neapolitanus
Authors: Shively J. M. , Ball Frances , Brown D. H. , Saunders R. E.
Published: October 2006

The polyhedral inclusions of
Thiobacillus neapolitanus
have been isolated; they contain ribulose diphosphate carboxylase.
Geologic Exploration of Taurus-Littrow: Apollo 17 Landing Site
Authors:   Apollo Field Geology Investigation Team
Published: October 2006

Apollo 17 landed in a deep graben valley embaying the mountainous highlands southeast of the Serenitatis basin. Impact-generated breccias underlie the massifs adjacent to the valley, and basalt has flooded and leveled the valley floor. The dark mantle inferred from orbital photographs was not recognized as a discrete unit; the unusually thick regolith of the valley floor contains a unique high concentration of dark glass beads that may cause the low albedo of much of the surface.
Early Social Responses in
Gallus
: A Functional Analysis
Authors: Graves H. B.
Published: October 2006

Early socialization leads to the establishment of species awareness, or imprinting, in many birds and mammals.
Gallus
chicks normally develop species-specific preferences prior to exposure to a parent, but early exposure is necessary to maintain these preferences. Descriptive rather than functional analyses have led to apparent disagreement about early socialization behavior; from an ecological viewpoint, such behavior is both adaptive and predictable.
β
2
-Microglobulin: Association with Lymphocyte Receptors
Authors: Bach Marilyn L. , Huang Shi-Wen , Hong Richard , Poulik M. David
Published: October 2006

β
2
-Microglobulin (β
2
m) is a low-molecular-weight protein constituent of lymphocyte membranes. Amino acid sequence analysis has revealed a high degree of homology between the β
2
m and certain regions of immunoglobulin molecules, suggesting a possible recognition function for the β
2
m, in analogy with the immunoglobulins. The data presented demonstrate that highly specific antiserum against β
2
m blocks lymphocyte reactivity against allogeneic cells in mixed leukocyte cultures and against phytohemagglutinin, both of which processes presumably function via a cell surface receptor on thymus-derived (T) lymphocytes. There is very little inhibition of T lymphocyte rosette formation with sheep red blood cells. The findings suggest a possible relation between the β
2
m and recognition units on the T lymphocyte surface.
The Imaging Photopolarimeter Experiment on Pioneer 10
Authors: Gehrels T. , Coffeen D. , Tomasko M. , Doose L. , Swindell W. , Castillo N. , Kendall J. , Clements A. , Hmeen-Anttila J. , Knight C. Ken , Blenman C. , Baker R. , Best G. , Baker L.
Published: October 2006

A 2.5-centimeter telescope aboard Pioneer 10 is capable of making two-dimensional spin-scan maps of intensity and polarization in red and blue light at high spatial resolution. During the recent flyby of Jupiter, a large quantity of imaging and polarimetric data was obtained on Jupiter and the Galilean satellites over a wide range of phase angles.
Biosynthesis of α-Ecdysone by Prothoracic Glands in vitro
Authors: Chino Haruo , Sakurai Syo , Ohtaki Tetsuya , Ikekawa Nobuo , Miyazaki Hiroshi , Ishibashi Masataka , Abuki Hideo
Published: October 2006

An in vitro study in which isolated prothoracic glands of the
Bombyx
silkworm were cultured has provided definite evidence that the prothoracic gland is the site where molting hormone is synthesized. The hormone behaved very similarly to free ecdysone on thin-layer chromatography. Analysis by liquid chromatography and mass fragmentography revealed that the hormone is identical with α-ecdysone.
Persistence of Cadmium-Induced Metabolic Changes in Liver and Kidney
Authors: Singhal Radhey L. , Merali Z. , Kacew S. , Sutherland D. J. B.
Published: October 2006

Daily intraperitoneal injection of cadmium chloride (1 milligram per kilogram) for 45 days enhanced gluconeogenesis as evidenced by significant increases in the activities of liver and kidney cortex pyruvate carboxylase, phosphopyruvate carboxylase, hexosediphosphatase, and glucose-6-phosphatase, the quartet of key, rate-limiting enzymes involved in the biotransformation of noncarbohydrate precursors into glucose. Whereas cadmium treatment decreased the level of hepatic glycogen, the concentration of blood glucose and urea was significantly elevated by this heavy metal. Discontinuation of the heavy metal treatment for 28 days, in rats previously injected with cadmium for 45 days, failed to restore the observed biochemical alterations in hepatic and renal carbohydrate metabolism to control values. Evidence indicates that cadmium augments the glucose-synthesizing capacity of liver and kidney cortex and that various metabolic changes persist even after a 4-week period of withdrawal from exposure to the heavy metal.
Venus: Mass, Gravity Field, Atmosphere, and Ionosphere as Measured by the Mariner 10 Dual-Frequency Radio System
Authors: Howard H. T. , Tyler G. L. , Fjeldbo G. , Kliore A. J. , Levy G. S. , Brunn D. L. , Dickinson R. , Edelson R. E. , Martin W. L. , Postal R. B. , Seidel B. , Sesplaukis T. T. , Shirley D. L. , Stelzried C. T. , Sweetnam D. N. , Zygielbaum A. I. , Esposito P. B. , Anderson J. D. , Shapiro I. I. , Reasenberg R. D.
Published: October 2006

Analysis of the Doppler tracking data near encounter yields a value for the ratio of the mass of the sun to that of Venus of 408,523.9 ± 1.2, which is in good agreement with prior determinations based on data from Mariner 2 and Mariner 5. Preliminary analysis indicates that the magnitudes of the fractional differences in the principal moments of inertia of Venus are no larger than 10
-4
, given that the effects of gravity-field harmonics higher than the second are negligible. Additional analysis is needed to determine the influence of the higher order harmonics on this bound. Four distinct temperature inversions exist at altitudes of 56, 58, 61, and 63 kilometers. The X-band signal was much more rapidly attenuated than the S-band signal and disappeared completely at 52-kilometer altitude. The nightside ionosphere consists of two layers having a peak density of 10
4
electrons per cubic centimeter at altitudes of 140 and 120 kilometers. The dayside ionosphere has a peak density of 3 × 10
5
electrons per cubic centimeter at an altitude of 145 kilometers. The electron number density observed at higher altitudes was ten times less than that observed by Mariner 5, and no strong evidence for a well-defined plasmapause was found.
Enhancement of Growth of Virulent Strains of
Escherichia coli
by Interleukin-1
Authors: Porat Reuven , Clark Burton D. , Wolff Sheldon M. , Dinarello Charles A.
Published: October 2006

Interleukin-1 (IL-1) is a polypeptide cytokine that mediates many physiological responses to infection and inflammation and is a growth factor for certain mammalian cells. Virulent and avirulent clinical isolates of
Escherichia coli
were grown in culture media in the presence of human IL-1. IL-1β, but not tumor necrosis factor or IL-4, enhanced the growth of virulent, but not avirulent,
E. coli
. This enhancement was blocked by the IL-1 receptor antagonist (IL-1ra). Radiolabeled IL-1 bound to virulent but not avirulent
E. coli
in a specific and saturable fashion; IL-1ra inhibited this binding. Thus, human IL-1 may recognize a functional IL-1-like receptor structure on virulent
E. coli
and may be a virulence factor for bacterial pathogenicity.
Radiohalos in a Radiochronological and Cosmological Perspective
Authors: Gentry Robert V.
Published: October 2006

New photographic evidence, data on halo ring sizes, and x-ray fluorescence analyses provide unambiguous evidence that polonium halos exist as a separate and distinct class apart from uranium halos. Because of the short half-lives of the polonium isotopes involved, it is not clear how polonium halos may be explained on the basis of currently accepted cosmological models of Earth formation.
Brain Capillary Blockage Produced by a Virulent Strain of Rodent Malaria
Authors: Yoeli Meir , Hargreaves Bruce J.
Published: October 2006

A sudden enhancement in virulence of a mild
Plasmodium berghei yoelii 17 x
strain resulted in fulminating and fatal infections in CF1 and A/J mice. The virulent strain has maintained its characteristics after ten cyclical transmissions through
Anopheles stephensi
. The visible expression of virulence of the mutated strain is its ability to cross the blood-brain barrier and cause intravascular sequestration of injected erythrocytes and blockage of brain capillaries. We, therefore, believe that the virulent line of
Plasmodium berghei yoelii 17 x
could serve as a useful laboratory model for the study of "cerebral malaria."
Fossil Plants and Coal: Patterns of Change in Pennsylvanian Coal Swamps of the Illinois Basin
Authors: Phillips Tom L. , Peppers Russel A. , Avcin Matthew J. , Laughnan Penelope F.
Published: October 2006

Coal palynology and studies of petrified peat indicate major changes in coal-swamp floras and the botanical constituents of coal throughout Pennsylvanian time. The changes are the result of broad climatic shifts and local environmental factors. The most striking is the change from a lycopod-dominated flora to one in which tree ferns were the major element. This change occurred at the Desmoinesian-Missourian (Westphalian-Stephanian) boundary and is probably multicontinental in scope.
A Heparin-Binding Growth Factor Secreted by Macrophage-Like Cells That Is Related to EGF
Authors: Higashiyama Shigeki , Abraham Judith A. , Miller Judy , Fiddes John C. , Klagsbrun Michael
Published: October 2006

Macrophage-like U-937 cells secrete a 22-kilodalton heparin-binding growth factor that is mitogenic for BALB-3T3 fibroblasts and smooth muscle cells, but not endothelial cells. The amino acid sequence predicted from complementary DNA clones indicates that the mitogen is a new member of the epidermal growth factor (EGF) family. This heparin-binding EGF-like growth factor (HB-EGF) binds to EGF receptors on A-431 epidermoid carcinoma cells and smooth muscle cells, but is a far more potent mitogen for smooth muscle cells than is EGF. HB-EGF is also expressed in cultured human macrophages and may be involved in macrophage-mediated cellular proliferation.
Spot-Scan Imaging in Transmission Electron Microscopy
Authors: Downing Kenneth H.
Published: October 2006

The determination of the structure of proteins and other organic materials by transmission electron microscopy is a rapidly developing field. Obtaining high-resolution images of these radiation-sensitive specimens has, until recently, been problematic. The development of spot-scan imaging, in which the electron beam is focused to a spot with a diameter of about 1000 angstroms and moved over the specimen to record the image, has overcome some of the most severe problems, which result from beam-induced motion of the specimen and its image. Elimination of this motion greatly enhances the contrast of high-resolution features of the image and promises a significant increase in the speed with which future structural work can be accomplished.
Regulation of Polyphosphoinositide-specific Phospholipase C Activity by Purified G
q
Authors: Smrcka Alan V. , Hepler John R. , Brown Kendall O. , Sternweis Paul C.
Published: October 2006

The hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP
2
) by phospholipase C yields the second messengers inositol 1,4,5-trisphosphate (InsP
3
) and 1,2-diacylglycerol. This activity is regulated by a variety of hormones through G protein pathways. However, the specific G protein or proteins involved has not been identified. The α subunit of a newly discovered pertussis toxin-insensitive G protein (G
q
) has recently been isolated and is now shown to stimulate the activity of polyphosphoinositide-specific phospholipase C (PI-PLC) from bovine brain. Both the maximal activity and the affinity of PI-PLC for calcium ion were affected. These results identify G
q
as a G protein that regulates PI-PLC.
Scatological Origin of Microvertebrate Fossil Accumulations
Authors: Mellett James S.
Published: October 2006

Small-mammal bone found in Recent carnivore droppings (scat) is identical in appearance with that in many Mesozoic and Tertiary microvertebrate fossil collections. Such fossil specimens passed into or through the digestive tracts of carnivores before being left as scat that was later reworked into sedimentary rocks. The term "coprocoenosis" is proposed for such an assemblage. Caution is urged in drawing conclusions about the composition of paleocommunities because carnivores can catch prey representing several different communities and leave a mixed assemblage in a particular depositional environment.
Methane Production in the Interstitial Waters of Sulfate-Depleted Marine Sediments
Authors: Martens Christopher S. , Berner Robert A.
Published: October 2006

Methane in the interstitial waters of anoxic Long Island Sound sediments does not reach appreciable concentrations until about 90 percent of seawater sulfate is removed by sulfate-reducing bacteria. This is in agreement with laboratory studies of anoxic marine sediments sealed in jars, which indicate that methane production does not occur until dissolved sulfate is totally exhausted. Upward diffusion of methane or its production in sulfate-free microenvironments, or both, can explain the observed coexistence of measurable concentrations of methane and sulfate in the upper portions of anoxic sediments.
Differentiation of 3T3-L1 Fibroblasts to Adipocytes Induced by Transfection of
ras
Oncogenes
Authors: Benito Manuel , Porras Almudena , Nebreda Angel R. , Santos Eugenio
Published: October 2006

Mammalian 3T3-L1 cells differentiate into adipocytes after continuous exposure to pharmacological doses of insulin or physiological doses of insulin-like growth factor I (IGF-1). Expression of transfected
ras
oncogenes led to differentiation of these cells into adipocytes in the absence of externally added insulin or IGF-I. Cells transfected with normal
ras
genes or the tyrosine kinase
trk
oncogene did not differentiate. Transfection with a dominant inhibitory
ras
mutant resulted in inhibition of differentiation. Exposure of untransfected 3T3-L1 cells to insulin stimulated formation of the active Ras⋅GTP complex. These observations indicate that Ras proteins participate in signal transduction pathways initiated by insulin and IGF-I in these cells.