bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphine Action at Central Nervous System Sites in Rat: Analgesia or Hyperalgesia Depending on Site and Dose
Authors: Jacquet Yasuko F. , Lajtha Abel
Published: October 2006

Morphine was injected via fine-gauge cannulas permanently implanted in various subcortical sites in the rat brain. In this way the blood-brain barrier was avoided and precise quantities of the drug were delivered to the intended sites. Ten micrograms of morphine in the posterior hypothalamus resulted in significant analgesia, while the same dose injected into the medial septum, the caudate, or the periaqueductal gray matter yielded hyperalgesia. The morphine-produced hyperalgesia at the last-mentioned site was accompanied by stereotyped violent circular leaps, an effect of morphine not previously reported. Thus, intracerebral injections of morphine differ significantly from systemic injections and produce either analgesia or hyperalgesia, depending on site and dose.
Cooperative Tool Use by Captive Hamadryas Baboons
Authors: Beck Benjamin B.
Published: October 2006

A bonded pair of hamadryas baboons developed cooperative tool use without training. The male could get food with the tool but first had to get the tool from an adjoining cage which he could not enter. The female learned to give him the tool. Cooperation was temporarily disrupted by the terminal phase of the female's estrous inflation.
Impairment of Timing Behavior after Prolonged Alcohol Consumption in Rats
Authors: Walker Don W. , Freund Gerhard
Published: October 2006

Prolonged alcohol consumption (5 months) concomitant with adequate nutrition was found to impair the acquisition and performance of timing behavior. Alcohol was administered in the form of a liquid diet containing 35 percent ethanol-derived calories as the only source of fluid and calories. One control group received the identical liquid diet with isocaloric substitution of sucrose for ethanol, and another control group received laboratory chow and water without restriction. Thirty days after ethanol was discontinued in the diet, the alcohol-consuming rats were severely impaired in acquisition and performance of timing behavior as compared to controls.
Temperature Sensitive Programming of the Silkmoth Flight Clock: A Mechanism for Adapting to the Seasons
Authors: Truman James W.
Published: October 2006

When males of the silkmoth
Antheraea pernyi
were exposed to 12°C during adult development and then tested for flight activity at 25°C, the time of the onset of the activity was advanced to the early part of the night. This change in the time of activity was stable and persisted through the life of the moth. Females showed a corresponding shift in the time of sex pheromone release when they were treated in the same fashion.
Spring Shoot Growth in Douglas-Fir May Be Initiated by Gibberellins Exported from the Roots
Authors: Lavender D. P. , Sweet G. B. , Zaerr J. B. , Hermann R. K.
Published: October 2006

Trials conducted under controlled environments demonstrated that the delay of bud activity of Douglas-fir (
Pseudotsuga menziesii
) seedlings occasioned by low temperature of the soil could be eliminated by application of gibberellic acid. Analyses of field-grown plants showed a parallel increase in bud activity, level of gibberellin-like compounds in xylem sap, and soil temperature during February and March.
Mammary Carcinoma: Enzymatic Block in Disialoganglioside Biosynthesis
Authors: Keenan T. W. , Morré D. James
Published: October 2006

The sialyl transferase of disialoganglioside formation is depressed in mammary tumors induced in the rat by 7,12-dimethylbenz[
a
]anthracene. Specific activities of other glycosyltransferases of the pathway ceramide to monosialoganglioside are unchanged or elevated so that the ganglioside GM
1
accumulates and higher gangliosides are depressed. These findings with a solid tumor are critical to an involvement of gangliosides in the cell-surface changes of tumorigenesis.
Benefits and Costs of HIV testing
Authors: Bloom David E. , Glied Sherry
Published: October 2006

The benefits and costs of human immunodeficiency virus (HIV) testing in employment settings are examined from two points of view: that of private employers whose profitability may be affected by their testing policies and that of public policy-makers who may affect social welfare through their design of regulations related to HIV testing. The results reveal that HIV testing is clearly not cost-beneficial for most firms, although the benefits of HIV testing may outweigh the costs for some large firms that offer generous fringe-benefit packages and that recruit workers from populations in which the prevalence of HIV infection is high. The analysis also indicates that the testing decisions of unregulated employers are not likely to yield socially optimal economic outcomes and that existing state and federal legislation related to HIV testing in employment settings has been motivated primarily by concerns over social equity.
An Analog of Myristic Acid with Selective Toxicity for African Trypanosomes
Authors: Doering Tamara L. , Raper Jayne , Buxbaum Laurence U. , Adams Steven P. , Gordon Jeffrey I. , Hart Gerald W. , Englund Paul T.
Published: October 2006

Trypanosoma brucei
, the protozoan parasite responsible for African sleeping sickness, evades the host immune response through the process of antigenic variation. The variant antigen, known as the variant surface glycoprotein (VSG), is anchored to the cell surface by a glycosyl phosphatidylinositol (GPI) structure that contains myristate (
n
-tetradecanoate) as its only fatty acid component. The utilization of heteroatom-containing analogs of myristate was studied both in a cell-free system and in vivo. Results indicated that the specificity of fatty acid incorporation depends on chain length rather than on hydrophobicity. One analog, 10-(propoxy)decanoic acid, was highly toxic to trypanosomes in culture although it is nontoxic to mammalian cells.
Spheroid Chromatin Units (ν Bodies)
Authors: Olins Ada L. , Olins Donald E.
Published: October 2006

Linear arrays of spherical chromatin particles (ν bodies) about 70 angstroms in diameter have been observed in preparations of isolated eukaryotic nuclei swollen in water, centrifuged onto carbon films, and positively or negatively stained. These bodies have been found in isolated rat thymus, rat liver, and chicken erythrocyte nuclei. Favorable views also reveal connecting strands about 15 angstroms wide between adjacent particles.
The Keller Plan in Science Teaching
Authors: Kulik James A. , Carmichael Kevin , Kulik Chen-Lin
Published: October 2006

A review of evaluative research on the Keller plan establishes the following points:

1) The Keller plan is an attractive teaching method to most students. In every published report, students rate the Keller plan much more favorably than teaching by lecture.

2) Self-pacing and interaction with tutors seem to be the features of the Keller courses most favored by students.

3) Several investigators report higher-than-average withdrawal rates for their Keller sections. The conditions that influence withdrawal and procrastination in Keller courses have been studied, and it seems possible to control procrastination and withdrawal through course design.

4) Content learning (as measured by final examinations) is adequate in Keller courses. In the published studies, final examination performance in Keller sections always equals, and usually exceeds, performance in lecture sessions.

5) Students almost invariably report that they learn more in PSI than in lecture courses, and also nearly always report putting more time and effort into the Keller courses.
Detection of Radon Emission at the Edges of Lunar Maria with the Apollo Alpha-Particle Spectrometer
Authors: Gorenstein Paul , Golub Leon , Bjorkholm Paul
Published: October 2006

The distribution of radioactive polonium-210, a decay product of radon-222, shows enhanced concentrations at the edges of lunar maria. Enhancements are seen at the edges of Mare Fecunditatis, Mare Crisium, Mare Smythii. Mare Tranquillitatis, Mare Nubium, Mare Cognitum, and Oceanus Procellarum. The observation is indicative of the transient emission of radon gas from the perimeters of lunar maria.
Fecal Bacterial β-Glucuronidase: Control by Diet
Authors: Reddy Bandaru S. , Weisburger John H. , Wynder Ernest L.
Published: October 2006

The effect of a mixed Western, high meat diet or a nonmeat diet on the intestinal bacterial β-glucuronidase activity was studied in human volunteers. This enzyme was significantly higher in stools of subjects on a high meat diet as compared to the nonmeat regimen. Thus, intestinal flora of subjects on a high meat diet was more able to hydrolyze glucuronide conjugates than that of individuals on a nonmeat diet. This, in turn, may raise the amount of substances, such as carcinogens, within the colonic lumen.
Coal and the Present Energy Situation
Authors: Osborn Elburt F.
Published: October 2006

To summarize, we must make greater use of coal, an energy resource that the nation has in great abundance, if we are to approach our former position of self-sufficiency in energy production.

The first step is to move immediately to replace the oil and gas used in electric generating plants with coal and to require that coal be used in fossil fuel electric plants planned or under construction in the next few years. The technology to remove sulfur and particulates from the stack gases is at hand, and therefore environmental regulations can be met.

Producing and transporting the required increased tonnages of coal are problems that can be met with appropriate incentives to the coal and transportation industries. Improved mining technology would be helpful but is not a requirement.

Oil and gas from coal should be in significant commercial production in about a decade. Underground, or in situ, gasification of coal, now in field tests, looks promising as a practical process for recovering the energy from coal, especially in deep or thick beds that cannot be mined efficiently.

Recoverable methane occurs in coal beds in the United States in an amount approximately equal to the total reserves of natural gas—about 260 trillion cubic feet. This large reserve of natural gas should be exploited as quickly as possible. Only minor investments in exploration and modest advances in technology are required.

Finally, as coal production is expanded. adequate planning and the most modern technology should be used to ensure that coal is extracted with maximum recovery and with minimum damage to the environment.
Increased Surface Albedo in the Northern Hemisphere
Authors: Kukla George J. , Kukla Helena J.
Published: October 2006

Routine mapping of snow and ice fields in the northern hemisphere was started by NOAA in 1967. Large year-to-year variations of the snow and pack-ice covers were observed. The annual mean coverage increased by 12 percent during 1971 and has remained high. The index
R
, which shows the approximate amount of energy reflected from the surface by snow and ice under the mean cloudiness, increased correspondingly. Thus, if the cloud cover over the snow fields did not increase substantially, the anomalous weather patterns of 1972 and 1973 could have been connected with the deficit in surface heat exchange which originated in the northern hemisphere the year before. During the past 7 years the largest changes occurred in the fall and in the continental interiors of Asia and America.

Two synoptic parameters which could readily provide information on the development of snow and ice cover in the northern hemisphere are (i) the total area momentarily covered and (ii) the running annual mean of snow and ice coverage for the preceding 1-year period. By 20 September 1973 the annual mean coverage was 37.3 × 10
6
km
2
, 11 to 12 percent higher than at the same time during 1968 through 1970. Snow cover-fall, the season when 15 × 10
6
to 55 × 10
6
km
2
of the northern hemisphere is covered with snow and ice, started on 20 September 1973, compared to 17 September 1972 and 5 or 10 October during 1967 through 1970.

The links between the atmosphere, the oceans, and the land surfaces must be better understood before the role of snow and ice can be thoroughly explained and exploited for long-range weather forecasting. But it is clear that snow, hitherto almost overlooked in synoptic meteorological reports, must be important in the mechanism of weather changes.
Temporal Pattern Shifts to Avoid Acoustic Interference in Singing Birds
Authors: Ficken Robert W. , Ficken Millicent S. , Hailman Jack P.
Published: October 2006

Two species of forest birds, the least flycatcher and the red-eyed vireo, when breeding in the same season in the same habitat, adjust their temporal pattern of singing to avoid the overlapping of songs. The avoidance of acoustic interference is more marked in the flycatcher, which has a briefer song than the vireo.
Choline Content of Rat Brain
Authors: Stavinoha W. B. , Weintraub S. T.
Published: October 2006

The free choline concentration in the rat brain was found to be 26.3 nanomoles per gram of brain tissue. This value was obtained through use of 6-second microwave irradiation for killing animals and inactivating enzymes, followed by a pyrolysis-gas chromatographic assay procedure. The identities of compounds measured from brain samples were verified by mass spectrometry.
Host-Specific Phytotoxic Polysaccharide from Apple Tissue Infected by
Erwinia amylovora
Authors: Goodman R. N. , Huang J. S. , Huang Pi-Yu
Published: October 2006

A toxin isolated from apple fruit tissue infected by
Erwinia amylovora
is 98 percent galactose in polymeric form, 0.375 percent protein, and has an average molecular weight of approximately 165,000. Young shoots of rosaceous, but not nonrosaceous, species wilt in a manner characteristic of the disease when placed in toxin solutions with concentrations as low as 10 micrograms per milliliter. Varieties of apple and pear susceptible to
Erwinia amylovora
wilt in 1 to 3 hours, whereas resistant varieties display symptoms 12 to 24 hours after treatment.
Functional Importance of Sequence in the Stem-Loop of a Transcription Terminator
Authors: Cheng Sheau-Wei C. , Lynch Eileen C. , Leason Kenneth R. , Court Donald L. , Shapiro Bruce A. , Friedman David I.
Published: October 2006

Intrinsic transcription terminators of prokaryotes are distinguished by a common RNA motif: a stem-loop structure high in guanine and cytosine content, followed by multiple uridine residues. Models explaining intrinsic terminators postulate that the stem-loop sequence is necessary only to form structure. In the tR2 terminator of coliphage λ, single-nucleotide changes reducing potential RNA stem stability eliminated tR2 activity, and a compensatory change that restored the stem structure restored terminator activity. However, multiple changes in the stem sequence that should have either maintained or increased stability reduced terminator activity. These results suggest that the ability of the stem-loop structure to signal transcription termination depends on sequence specificity and secondary structure.
Dexamethasone Stimulation of Murine Mammary Tumor Virus Expression: A Tissue Culture Source of Virus
Authors: Parks Wade P. , Scoinick Edward M. , Kozikowski Edmund H.
Published: October 2006

In mouse cell lines derived from mammary adenocarcinomas, the synthetic steroid dexamethasone stimulates production of murine mammary tumor virus. Viral RNA and antigens are increased as much as 20-fold, and culture fluid supernatants from steroid-treated cells contain type B particles with reverse transcriptase. These cells provide a possible tissue culture source of this virus and a model system for studying the mechanism of action of corticosteroids and the regulation of transcription of integrated viral DNA.
Pineal Gland: 24-Hour Rhythm in Norepinephrine Turnover
Authors: Brownstein Michael , Axelrod Julius
Published: October 2006

There is a 24-hour rhythm in the turnover of norepinephrine in sympathetic nerves innervating the pineal gland. This rhythm persists in blinded animals but is suppressed in normal rats by light. The rhythm in norepinephrine turnover generates the rhythms in pineal indoleamines and
N
-acetyltransferase.
Dopamine Nerve Terminals in the Rat Limbic Cortex: Aspects of the Dopamine Hypothesis of Schizophrenia
Authors: Hkfelt T. , Ljungdahl . , Fuxe K. , Johansson O.
Published: October 2006

The existence of cortical dopamine nerve terminals is demonstrated with a highly sensitive modification of the Falck-Hillarp fluorescence technique. This confirms previous biochemical reports of high dopamine levels in the cortex. The histochemistry reveals that the distribution is regional and confined to the limbic cortex.
X-ray Photoelectron Spectroscopic Studies of Interactions in Multicomponent Metal and Metal Oxide Thin Films
Authors: Winograd Nicholas , Baitinger W. E. , Amy J. W. , Munarin J. A.
Published: October 2006

Changes in chemical oxidation states in alloys and at solid-solid interfaces were monitored by using x-ray photoelectron spectroscopy. For an oxidized Nichrome surface, the chromium component was selectively converted to chromic oxide while nickel remained in the metallic state. When this surface was overlaid with a 20-angstrom-thick aluminum film, the chromic oxide was reduced to chromium and the aluminum was oxidized to aluminum oxide in a reaction zone consisting of no more than 10 angstroms of the interface. This scheme appeared general for solid-solid contacts and was predicted, to a first approximation, by bulk thermodynamic free energies.
Thiocarbamate Sulfoxides: Potent, Selective, and Biodegradable Herbicides
Authors: Casida John E. , Gray Reed A. , Tilles Harry
Published: October 2006

Sulfoxidation of thiocarbamates yields a new class of chemicals having increased herbicidal activity along with greater tolerance of corn and soybeans in greenhouse tests. However, their thermal stability is not favorable. These sulfoxides are intermediates in the mammalian metabolism of thiocarbamates, being formed by liver microsomal oxidases and cleaved in a system consisting of glutathione and a soluble enzyme from liver.
Equatorial Jet in the Indian Ocean: Theory
Authors: O'Brien James J. , Hurlburt H. E.
Published: October 2006

A nonlinear numerical model and a simple analytical theory explain the basic features of the equatorial surface jet in the Indian Ocean recently reported by Wyrtki. The observed width of this transient current, 500 kilometers, is given theoretically by twice the baroclinic equatorial radius of deformation. The numerical model reproduces all Wyrtki's observations of this natural phenomenon.
Geckos: Adaptive Significance and Energetics of Tail Autotomy
Authors: Congdon J. D. , Vitt L. J. , King W. W.
Published: October 2006

Coleonyx variegatus
is adapted to readily sacrifice its tail to predators. This adaptation is associated with characteristic tail behavior and rapid tail regeneration. There is no facultative metabolic increase associated with tail regeneration, and energy normally allocated to body growth and maintenance is diverted to tail regeneration. This supports the contention that tail behavior, autotomy, and rapid regeneration evolved as mechanisms promoting survival in terms of predator escape.
Expression cDNA Cloning of the KGF Receptor by Creation of a Transforming Autocrine Loop
Authors: Miki Toru , Fleming Timothy P. , Bottaro Donald P. , Rubin Jeffrey S. , Ron Dina , Aaronson Stuart A.
Published: October 2006

An expression cloning strategy was devised to isolate the keratinocyte growth factor (KGF) receptor complementary DNA. NIH/3T3 fibroblasts, which secrete this epithelial cell-specific mitogen, were transfected with a keratinocyte expression complementary DNA library. Among several transformed foci identified, one demonstrated the acquisition of specific high-affinity KGF binding sites. The pattern of binding competition by related fibroblast growth factors (FGFs) indicated that this receptor had high affinity for acidic FGF as well as KGF. The rescued 4.2-kilobase complementary DNA was shown to encode a predicted membrane-spanning tyrosine kinase related to but distinct from the basic FGF receptor. This expression cloning approach may be generally applicable to the isolation of genes that constitute limiting steps in mitogenic signaling pathways.
Regulation of Interleukin-2 Gene Enhancer Activity by the T Cell Accessory Molecule CD28
Authors: Fraser James D. , Irving Bryan A. , Crabtree Gerald R. , Weiss Arthur
Published: October 2006

The mechanism by which cell surface molecules regulate T cell production of lymphokines is poorly understood. Production of interleukin-2 (IL-2) can be regulated by signal transduction pathways distinct from those induced by the T cell antigen receptor. Stimulation of CD28, a molecule expressed on most human T cells, induced the formation of a protein complex that bound to a site on the
IL-2
gene distinct from previously described binding sites and increased
IL-2
enhancer activity fivefold. The CD28-responsive complex bound to the
IL-2
gene between -164 and -154 base pairs from the transcription start site. The sequence of this element is similar to regions conserved in the 5′ flanking regions of several other lymphokine genes.
The
myoD
Gene Family: Nodal Point During Specification of the Muscle Cell Lineage
Authors: Weintraub Harold , Davis Robert , Tapscott Stephen , Thayer Matthew , Krause Michael , Benezra Robert , Blackwell T. Keith , Turner David , Rupp Ralph , Hollenberg Stanley , Zhuang Yuan , Lassar Andrew
Published: October 2006

The
myoD
gene converts many differentiated cell types into muscle. MyoD is a member of the basic-helix-loop-helix family of proteins; this 68-amino acid domain in MyoD is necessary and sufficient for myogenesis. MyoD binds cooperatively to muscle-specific enhancers and activates transcription. The helix-loop-helix motif is responsible for dimerization, and, depending on its dimerization partner, MyoD activity can be controlled. MyoD senses and integrates many facets of cell state. MyoD is expressed only in skeletal muscle and its precursors; in nonmuscle cells
myoD
is repressed by specific genes. MyoD activates its own transcription; this may stabilize commitment to myogenesis.
Paths of Information Flow Through Visual Cortex
Authors: Mignard Marc , Malpeli Joseph G.
Published: October 2006

The main route of information flow in the cerebral cortex is from the middle layers of cortex to upper and lower layers. However, upper layers of the cat primary visual cortex can be directly driven by inputs from secondary visual cortex when activity in middle layers is disrupted. Upper-layer activity can be driven either by middle layers or by direct corticocortical inputs. One consequence of this result is that areas of cortex thought to be carrying out low-order analysis may be able to extract considerable information from higher order areas.
Mercury: Results on Mass, Radius, Ionosphere, and Atmosphere from Mariner 10 Dual-Frequency Radio Signals
Authors: Howard H. T. , Tyler G. L. , Esposito P. B. , Anderson J. D. , Reasenberg R. D. , Shapiro I. I. , 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. , Wood G. E. , Zygielbaum A. I.
Published: October 2006

Analysis of the radio-tracking data from Mariner 10 yields 6,023,600 ± 600 for the ratio of the mass of the sun to that of Mercury, in very good agreement with values determined earlier from radar data alone. Occultation measurements yielded values for the radius of Mercury of 2440 ± 2 and 2438 ± 2 kilometers at latitudes of 2°N and 68°N, respectively, again in close agreement with the average equatorial radius of 2439 ± 1 kilometers determined from radar data. The mean density of 5.44 grams per cubic centimeter deduced for Mercury from Mariner 10 data thus virtually coincides with the prior determination. No evidence of either an ionosphere or an atmosphere was found, with the data yielding upper bounds on the electron density of about 1500 and 4000 electrons per cubic centimeter on the dayside and nightside, respectively, and an inferred upper bound on the surface pressure of 10
-8
millibar.
Motor Pattern Production in Reciprocally Inhibitory Neurons Exhibiting Postinhibitory Rebound
Authors: Perkel Donald H. , Mulloney Brian
Published: October 2006

Pairs of neurons which inhibit each other can produce regular alternating bursts of impulses if they also exhibit postinhibitory rebound (PIR). Computer studies show that stable patterns occur spontaneously in systems of pacemaker neurons with PIR, and can be triggered in systems of nonpacemakers without requiring tonic excitation. The repetition rates of these patterns are determined largely by the PIR parameters. The patterns resist perturbation by phasic synaptic inputs, but can be modulated or turned off by tonic inputs. One pair of PIR neurons can be entrained by another pair with a different repetition rate to produce more complex firing patterns.
Lectins: A Possible Basis for Specificity in the
Rhizobium
—Legume Root Nodule Symbiosis
Authors: Bohlool B. B. , Schmidt E. L.
Published: October 2006

Soybean lectin labeled with fluorescein isothiocyanate combined specifically with all but 3 of 25 strains of the soybean-nodulating bacterium
Rhizobium japonicum
. The lectin did not bind to any of 23 other strains representative of rhizobia that do not nodulate soybeans. The evidence suggests that an interaction between legume lectins and
Rhizobium
cells may account for the specificity expressed between rhizobia and host plant in the initiation of the nitrogen-fixing symbiosis.
Ammonia Flux into the Atmosphere from a Grazed Pasture
Authors: Denmead O. T. , Simpson J. R. , Freney J. R.
Published: October 2006

A micrometeorological technique has been used to measure the flux of ammonia and related gaseous nitrogen compounds into the atmosphere from a pasture grazed by sheep. During 3 weeks in late summer, the average daily flux density of nitrogen in these forms was 0.26 kilogram per hectare. This is a substantial part of the nitrogen turnover in grazed pastures.
Blepharmone: A Conjugation-Inducing Glycoprotein in the Ciliate
Blepharisma
Authors: Miyake Akio , Beyer Jens
Published: October 2006

Gamone 1 of
Blepharisma intermedium
was isolated, identified as a slightly basic glycoprotein (molecular weight, 2 x 10
4
), and designated as blepharmnone. At the concentration of 6 x 10
-8
milligram per milliliter, it specifically transforms mating type 2 cells, so that they can conjugate in about 2 hours.
Hyporheic Communities of Two Montana Rivers
Authors: Stanford Jack A. , Gaufin Arden R.
Published: October 2006

Collections of stream organisms from a domestic water supply system adjacent to the Tobacco River revealed that a detritus-based community exists in subterranean waters circulating through floodplain gravels at least 4.2 meters below and 50 meters laterally from the river channel. Several stone fly species spend their entire nymphal life cycles in underground habitats of the Flathead and Tobacco rivers.
Toxic Polyneuropathy Produced by Methyl
N
-Butyl Ketone
Authors: Mendell J. R. , Saida K. , Ganansia M. F. , Jackson D. B. , Weiss H. , Gardier R. W. , Chrisman C. , Allen N. , Couri D. , O'Neill J. , Marks B. , Hetland L.
Published: October 2006

A polyneuropathy affecting a large number of workers was recently observed at a plant producing plastic-coated and color-printed fabrics. Epidemiological data suggested strongly that methyl
N
-butyl ketone (MBK) was responsible for the outbreak. This hypothesis is now supported by the development of a peripheral neuropathy in chickens, rats, and cats exposed to MBK at atmospheric concentrations of 200 to 600 parts per million, 24 hours per day, 7 days per week. Although the animals were exposed continuously and the affected workers were exposed intermittently, the averages of the total number of hours of exposure for development of the peripheral neuropathy in the animals and workers were remarkably close.
Abortion, Illegitimacy, and the American Birth Rate
Authors: Sklar June , Berkov Beth
Published: October 2006

In sum, it appears that legal abortion depressed overall fertility, but particularly illegitimate fertility, by giving women an opportunity to terminate their pregnancies when other means of birth control either had not been used or had failed. If legalized abortion had not been available, an estimated additional 39,000 illegitimate babies and 28,000 legitimate babies would have been born in 1971 in the United States. While this makes up a small part of total births (3,500,000), the illegitimate births prevented represent almost one-tenth of all out-of-wedlock children born in the country in that year. In addition to preventing these births the legalization of abortion appears to have reduced the incidence of pregnancy-related marriages and thereby may have helped to limit subsequent marital disruption. Finally, legal abortion prevented large numbers of illegal abortions from occurring. Our data indicate that well over half—most likely between two-thirds and three-fourths—of all legal abortions in the United States in 1971 were replacements for illegal abortions.

Further declines in illegitimate birth rates for the country as a whole will depend, in considerable part, on the extent to which legal abortion becomes more readily available and more widely used. Theoretically, greater use of efficient contraception could also cause illegitimate fertility to decline. But there are many reasons why women do not use efficient contraception even when they know about it and have access to the materials. Even though the use of abortion throughout the nation is now legalized by the Supreme Court decision, this does not necessarily mean that services will in fact be everywhere more readily available. Our interstate analysis suggests that should the liberalization of abortion laws be reversed, not only would there be an upturn in illegal abortions and pregnancy-related marriages, but also a marked rise in illegitimacy, particularly among women who do not have the means to obtain an illegal abortion.
Rod Origin of Prolonged Afterimages
Authors: MacLeod Donald I. A. , Hayhoe Mary
Published: October 2006

Afterimages fade against any unchanging background but generally reappear if the background changes suddenly. Under some conditions, however, a change of background color fails to revive a faded afterimage. This happens only if the interchanged backgrounds equally stimulate the rod receptors. It follows that afterimages seen under these conditions are generated by rods.
Induction by NGF of Meiotic Maturation of
Xenopus
Oocytes Expressing the
trk
Proto-Oncogene Product
Authors: Nebreda Angel R. , Martin-Zanca Dionisio , Kaplan David R. , Parada Luis F. , Santos Eugenio
Published: October 2006

The effect of nerve growth factor (NGF) was assessed in Xenopus oocytes expressing the human
trk
proto-oncogene product, p140
prototrk
. Oocytes injected with
trk
messenger RNA expressed polypeptides recognized by antibodies to the
trk
gene product. Exposure of these oocytes to nanomolar amounts of NGF resulted in specific surface binding of
125
I-labeled NGF, tyrosine phosphorylation of p140
prototrk
, and meiotic maturation, as determined by germinal vesicle breakdown and maturation promoting factor (p34
cdc2
kinase activation. Thus the
trk
proto-oncogene product can act as a receptor for NGF in a functionally productive manner.
Prospects for an Invasion: Competition Between
Aedes albopictus
and Native
Aedes triseriatus
Authors: Livdahl Todd P. , Willey Michelle S.
Published: October 2006

Competition between larval populations of the native North American treehole mosquito
Aedes triseriatus
and
Aedes albopictus
, recently introduced from Asia to North America, was assessed by comparing per capita growth rate estimates for experimental cohorts of larvae developing under a variety of initial density combinations in fluid obtained from tires or from treeholes. Estimates of carrying capacities and competition coefficients indicate that competition between the two species will result in stable coexistence in treehole communities but local extinction of
A. triseriatus
in tire habitats.
Biosynthesis and Function of Gangliosides
Authors: Fishman Peter H. , Brady Roscoe O.
Published: October 2006

Gangliosides are unique acidic glycolipids that are selectively concentrated in the plasma membrane of cells. Surface labeling studies have demonstrated that at least a portion of the oligosaccharide chain of gangliosides extends beyond the hydrophobic region of the cell membrane, whereas the lipid moiety of gangliosides (ceramide) is imbedded in the membrane bilayer. It is becoming increasingly apparent that gangliosides participate in the internalization of environmental signals elicited by cholera toxin and glycoprotein hormones such as thyrotropic hormone and chorionic gonadotropin as well as other substances such as interferon and possibly serotonin. The mechanism by which cholera toxin binds to a specific ganglioside receptor on the cell surface and subsequently activates adenylate cyclase provides a model for the interaction of trophic agents with gangliosides. We would predict that analogous phenomena involving gangliosides will be discovered in brain.

The biosynthesis of gangliosides proceeds by the ordered sequential addition of sugars to the lipid moiety. These reactions are catalyzed by a cluster of membrane-bound glycosyltransferases. Any alteration in the activity or specificity of one of these enzymes will result in a dramatic change in the ganglioside pattern of an afflicted cell or organ. The drastic consequences that accompany abnormalities of ganglioside synthesis have been documented in a heritable metabolic disorder in vivo and in tumorigenic transformation of cells in vitro. In this article, we have attempted to unify these observations and to provide a reasonable interpretation of the role of gangliosides in mediating cell surface phenomena.
Transcription-Dependent and Transcription-Independent Nuclear Transport of hnRNP Proteins
Authors: Piñol-Roma Serafín , Dreyfuss Gideon
Published: October 2006

Heterogeneous nuclear RNAs and specific nuclear proteins form heterogeneous nuclear ribonucleoprotein complexes (hnRNPs), one of the most abundant components of the nucleus. In mitosis, as the nuclear envelope breaks down, hnRNPs disperse throughout the cell. At the end of mitosis, hnRNPs dissociate and their proteins are transported into the daughter cell nuclei separately. Some are transported immediately (early group), while others are transported later (late group). Transport of the late group appears to require transcription by RNA polymerase II, in that inhibitors of this polymerase cause the late proteins to remain in the cytoplasm. Thus, there are two modes, transcription-dependent and transcription-independent, for the transport of nuclear proteins.
Methionine Adenosyltransferase Deficiency: New Enzymatic Defect Associated with Hypermethioninemia
Authors: Gaull Gerald E. , Tallan Harris H.
Published: October 2006

A specific deficiency of methionine adenosyltransferase has been demonstrated in the liver of an infant with hypermethioninemia. Since the enzymatic activity was below that in fetal liver and the metabolic abnormality has persisted (the infant now being 1 year of age), there is probably a genetic mutation. Mass screening for hypermethioninemia may uncover more such cases.
Marijuana and Driving in Real-Life Situations
Authors: Klonoff Harry
Published: October 2006

It is evident that the smoking of marijuana by human subjects does have a detrimental effect on their driving skills and performance in a restricted driving area, and that this effect is even greater under normal conditions of driving on city streets. The effect of marijuana on driving is not uniform for all subjects, however, but is in fact bidirectional; whether or not a significant decline occurs in driving ability is dependent both on the subject's capacity to compensate and on the dose of marijuana. For those subjects who improved their performance, the explanation may lie in overcompensation and possibly the sedative effect of the drug.

Whereas the street portion of this study approximated normal driving conditions, it should be emphasized that the context of the driving experience even on city streets was experimental. The design of this study provided maximal safeguards in terms of a dual control vehicle and a driver observer; in addition, the subjects were professionally screened and, with rare exception, they were emotionally stable. Given the experimental setting and set, the safeguards, and the nature of the study sample, idiosyncratic behavior that might occur under normal driving conditions would be less likely to occur in a study such as this.

Other identified factors might lead to more stringent conclusions regarding the effects of marijuana on driving. The first is night driving, which may be more stressful. But an even more important unanswered question is the cumulative effect of alcohol and marijuana on driving (64 percent of the study sample reported using alcohol in combination with marijuana before driving). Third, the doses of marijuana used in this study were within the range of social marijuana usage; more heroic doses might be taken before driving. Fourth, the effect of marijuana on reactions and decisions during high speed is still another unknown.

What are the recommendations that emerge from this study? Driving under the influence of marijuana should be avoided as much as should driving under the influence of alcohol. More investigation is urgently required—and high priority should be given to studies that approximate normal conditions of driving and in which alcohol and marijuana are administered to the same subjects.
Counterclockwise Circulation in the Pacific Subantarctic Sector of the Southern Ocean
Authors: McGinnis Richard F.
Published: October 2006

The distribution of isohalines in the upper 500 meters of Pacific subantarctic waters can be interpreted as evidence for an endemic counterclockwise circulation, the westward component of which is at 40 to 45 degrees south latitude. The distributions of a number of lanternfish species (family Myctophidae) lend support to such an interpretation.
Environmental Quality: Outline for a National Index for Canada
Authors: Inhaber H.
Published: October 2006

I have presented an approach to constructing an EQI for Canada. The index was divided into air, water, land, and miscellaneous sections. By noting individual subindices, it is possible to study how environmental conditions vary across the country. By combining the subindices, one can obtain a more crude gauge of the broad state of the environment. As indices and mathematical methods are improved, it may eventually be possible to measure this state in the same way as the economic state of the nation is measured now. The work described herein can be viewed as a simple guide to this measurement.
Coevolutionary Race Continues: Butterfly Larval Adaptation to Plant Trichomes
Authors: Rathcke Beverly J. , Poole Robert W.
Published: October 2006

Plant trichomes can act as effective defenses against herbivores, but at least one species of ithomiid butterfly,
Mechanitis isthmia
, has evolved a unique adaptation for avoiding the trichomes on its spiny
Solanum
hosts. The larvae are gregarious and together they spin a fine silk scaffolding over the tops of the spines on which they can crawl and feed in safety.
Genes for Epilepsy Mapped in the Mouse
Authors: Rise Matthew L. , Frankel Wayne N. , Coffin John M. , Seyfried Thomas N.
Published: October 2006

The neurological mutant mouse strain El is a model for complex partial seizures in humans. The inheritance of epileptic seizures with seven conventional chromosomal markers and over 60 endogenous proviral markers was studied by means of backcrosses of El with two seizure-resistant strains, DBA/2J and ABP/LeJ. The major gene responsible for this epileptic phenotype (
El-1
) was localized to a region distal with respect to the centromere on chromosome 9. At least one other gene,
El-2
, linked to proviral markers on chromosome 2, also influences the seizure phenotype. In addition, a potential modifier of seizures was detected in the DBA/2J background. The location of
El-1
on distal chromosome 9 may allow identification of an epilepsy candidate gene in humans on the basis of conserved synteny with human chromosome 3.
Laurentide Ice Sheet Meltwater Recorded in Gulf of Mexico Deep-Sea Cores
Authors: Kennett James P. , Shackleton N. J.
Published: October 2006

Oxygen isotopic measurements in three Late Quaternary deep-sea cores from the Gulf of Mexico record a major anomaly between about 15,000 and 12,000 years ago superimposed on a more characteristic oceanic oxygen isotopic curve. This resulted from major influx of isotopically light glacial meltwater via the Mississippi River from the disintegrating Late Wisconsin Laurentide Ice Sheet 2000 kilometers to the north.
Pseudomyrmex nigropilosa
: A Parasite of a Mutualism
Authors: Janzen Daniel H.
Published: October 2006

Pseudomyrmex nigropilosa
is a parasite of the ant-acacia mutualism in Central America in that it harvests the resources of swollen-thorn acacias but does not protect the acacias. In the process, it also lowers the rate of occupation by the obligate acacia-ants, species of ants that do protect swollen-thorn acacias. Tenancy of an acacia by
P. nigropilosa
must be temporary, since the unoccupied plant is shortly killed by herbivores or competing plants, or is taken over by obligate acacia-ants. As expected of a species of short-lived ant, a
P. nigropilosa
colony produces reproductives earlier in the life of the colony and maintains fewer grams of workers per gram of brood than does a colony of the long-lived obligate acacia-ants.
Ganymede: Observations by Radar
Authors: Goldstein R. M. , Morris G. A.
Published: October 2006

Radar cross-section measurements indicate that Ganymede scatters to Earth 12 percent of the power expected from a conducting sphere of the same size and distance. This compares with 8 percent for Mars, 12 percent for Venus, 6 percent for Mercury, and about 8 percent for the asteroid Toro. Furthermore, Ganymede is considerably rougher (to the scale of the wavelength used, 12.6 centimeters) than Mars, Venus, or Mercury. Roughness is made evident in this experiment by the presence of echoes away from the center of the disk. A perfectly smooth target would reflect only a glint from the center, whereas a very rough target would reflect power from over the entire disk.
Slow Persistent Infection Caused by Visna Virus: Role of Host Restriction
Authors: Haase Ashley T. , Stowring Linda , Narayan Opendra , Griffin Dianne , Price Donald
Published: October 2006

Proviral DNA has been demonstrated by in situ hybridization in foci of cells of a lamb infected with the RNA slow virus visna. A few of these cells also contain the major virion structural antigen p30. This restriction in virus gene expression in the infected animal provides a mechanism for persistence of virus in this chronic infection.
Endogenous Opiate Receptor Ligand: Electrically Induced Release in the Guinea Pig Ileum
Authors: Puig Margarita M. , Gascon Pedro , Craviso Gale L. , Musacchio José M.
Published: October 2006

Opiate receptors mediate the electrically evoked inhibition of the myenteric plexus-longitudinal muscle preparation of the guinea pig ileum. The electrically induced activation of the opiate receptor was produced by a prolonged simulation at 10 hertz and provides the first evidence that an endogenous opiate receptor ligand is released by nerve stimulation. The specificity of the phenomenon was demonstrated by the reversal obtained with the narcotic antagonists naloxone, naltrexone, and GPA 1843; GPA 1847, the (+)-isomer of 1843, did not cause reversal. The model system described should be useful for the study of the storage, synthesis, and release of endorphins.
HRR25, a Putative Protein Kinase from Budding Yeast: Association with Repair of Damaged DNA
Authors: Hoekstra Merl F. , Liskay R. Michael , Ou Alan C. , DeMaggio Anthony J. , Burbee David G. , Heffron Fred
Published: October 2006

In simple eukaryotes, protein kinases regulate mitotic and meiotic cell cycles, the response to polypeptide pheromones, and the initiation of nuclear DNA synthesis. The protein HRR25 from the budding yeast
Saccharomyces cerevisiae
was defined by the mutation
hrr25-1
. This mutation resulted in sensitivity to continuous expression of the HO double-strand endonuclease, to methyl methanesulfonate, and to x-irradiation. Homozygotes of
hrr25-1
were unable to sporulate and disruption and deletion of
HRR25
interfered with mitotic and meiotic cell division. Sequence analysis revealed two distinctive regions in the protein. The NH
2
-terminus of HRR25 contains the hallmark features of protein kinases, whereas the COOH-terminus is rich in proline and glutamine. Mutations in
HRR25
at conserved residues found in all protein kinases inactivated the gene, and these mutants exhibited the
hrr25
null phenotypes. Taken together, the
hrr25
mutant phenotypes and the features of the gene product indicate that
HRR25
is a distinctive member of the protein kinase superfamily.
A Difference in Hypothalamic Structure Between Heterosexual and Homosexual Men
Authors: LeVay Simon
Published: October 2006

The anterior hypothalamus of the brain participates in the regulation of male-typical sexual behavior. The volumes of four cell groups in this region [interstitial nuclei of the anterior hypothalamus (INAH) 1, 2, 3, and 4] were measured in postmortem tissue from three subject groups: women, men who were presumed to be heterosexual, and homosexual men. No differences were found between the groups in the volumes of INAH 1, 2, or 4. As has been reported previously, INAH 3 was more than twice as large in the heterosexual men as in the women. It was also, however, more than twice as large in the heterosexual men as in the homosexual men. This finding indicates that INAH is dimorphic with sexual orientation, at least in men, and suggests that sexual orientation has a biological substrate.
Volcanic Twilights from the Fuego Eruption
Authors: Volz F. E.
Published: October 2006

Striated twilight glows have been observed since 26 November 1974 in New England, indicating the spread of stratospheric dust earlier observed over Arizona. Similar photometric results were obtained from New Mexico and Florida, and twilights in Puerto Rico showed features not hitherto measured. Letters and verbal reports indicate the source to be eruptions of Fuego Volcano in Guatemala between 13 and 23 October 1974.
Hydroxyl Radical Concentrations Measured in Ambient Air
Authors: Wang Charles C. , Davis L. I. , Wu C. H. , Japar S. , Niki H. , Weinstock B.
Published: October 2006

Diurnal variations in the hydroxyl radical concentration of ambient air were measured for the first time by the technique of laser-induced fluorescence.
Potential for Converting Wood into Plastics
Authors: Goldstein Irving S.
Published: October 2006

The conversion of wood into chemicals for the production of most of our synthetic plastics, fibers, and rubbers is technically feasible. With refinements in technology a large integrated plant utilizing all components of the wood for production of ethanol (to be further processed to ethylene and butadiene), phenols and furfural would be approaching economic feasibility as well at current petrochemical prices. If crude oil prices continue to climb at a faster rate than wood costs, the economic feasibility of chemicals for polymers from wood would become certain.

Although technical feasibility has not been established, synthetic oils from liquefaction of wood might serve as feedstocks for cracking to chemicals in the same way that crude oil is presently used.

The fulfillment of all our polymer needs from wood as a raw material should not place an impossible burden on our wood supply, but might actually improve the availability of wood for lumber, plywood and pulp by providing a use for less valuable wood which would allow reforestation and improved forest management.