bluuebunny/crossref_metadata_2025 huggingface dataset:
Evoked Potential Correlates of Response Criterion in Auditory Signal Detection
Authors: Paul Dina Doré , Sutton Samuel
Published: October 2006

The amplitude of a late positive component of the average evoked potential recorded from the human scalp varied systematically as a function of the observer's response criterion as defined within the context of signal detection theory. With signal intensity invariant, the P
3
component of the evoked potential increased monotonically with increasing strictness of the criterion. The results are viewed as supporting the signal detection theory approach to the analysis of discrimination behavior as well as providing further evidence of the sensitivity of P
3
to the manipulation of psychological variables.
Amphotericin B Potentiation of Rifampicin as an Antifungal Agent against the Yeast Phase of
Histoplasma capsulatum
Authors: Kobayashi G. S. , Medoff G. , Schlessinger D. , Kwan C. N. , Musser W. E.
Published: October 2006

Rifampicin, at high concentrations, inhibited growth and RNA synthesis in the yeast phase of
Histoplasma capsulatum
. These effects were potentiated by low concentrations of amphotericin B. The combination of the two agents was fungicidal, whereas each alone, at much higher concentrations, was only fungistatic.
Biological Damage from Intranuclear Tritium: DNA Strand Breaks and Their Repair
Authors: Cleaver J. E. , Thomas G. H. , Burki H. J.
Published: October 2006

Isotopic decay in tritiated thymidine in the DNA of frozen (-196°C) Chinese hamster cells causes breaks in DNA strands to accumulate at a rate of 2.1 breaks per decay. After DNA is thawed the tritium-induced breaks repair rapidly with a half-time of 15 minutes at 37°C. In comparison to breakage by x-rays, the efficiency of DNA strand breakage by tritium is equivalent to 0.48 rad per decay. This dose per decay is close to that predicted by simple dosimetric considerations (0.38 rad per decay) for irradiation by the β particles from tritium.
Phosphorescence of Adsorbed Ionic Organic Molecules at Room Temperature
Authors: Schulman Edward M. , Walling Cheves
Published: October 2006

Many salts of polynuclear carboxylic acids, phenols, amines, and sulfonic acids adsorbed on paper, silica, alumina, and other substrates exhibit strong triplet phosphorescence at room temperature, with no evidence of quenching by oxygen. No phosphorescence has been observed with nonionic materials. The spectra are similar to those of frozen solutions at -196°C, and the technique provides a simple means of demonstrating phosphorescence phenomena, identifying unknown materials, and investigating the spectra of triplet states.
North Atlantic Ocean: Preliminary Description of Normal Modes
Authors: Platzman George W.
Published: October 2006

The three lowest gravitational modes of free oscillation of the North Atlantic Ocean are estimated by numerical integration of Laplace's tidal equations. These modes have periods of approximately 21, 14, and 11 hours, and structures, respectively, of one, two, and three positive amphidromic systems. The phase distribution of the first mode resembles cotidal charts of the diurnal tide, and the period of the second mode is consistent with that inferred by Wunsch from tidal data in Bermuda and the Azores.
Metacontrast and Saccadic Suppression
Authors: Matin Ethel , Clymer Arthur B. , Matin Leonard
Published: October 2006

A vertical slit of light illuminated during horizontal saccadic eye movements appeared as a horizontally extended smear when stimulation was terminated before the saccade ended. However, on trials for which duration of illumination of the slit was extended into the period after the saccade, the smear appeared shorter and dimmer, and a clear image of the slit was seen. With further increases in duration, no smears were seen at the highest luminance of the slit employed, although smears were more than 2 log units above threshold when flashes were brief. This saccadic suppression is discussed in terms of metacontrast, with the accumulated luminance in the period after the saccade primarily responsible for masking the effects of the stimulation received during the movement of the eye.
Fourier Transform Spectroscopy
Authors: Becker Edwin D. , Farrar T. C.
Published: October 2006

The recent introduction of Fourier transform methods is revolutionizing IR and NMR spectroscopy. The application of IR interferometry or of NMR pulse methods, followed by Fourier transformation of the resultant interferogram, permits acquisition of spectral data in a time that is orders of magnitude less than by conventional spectroscopic methods. This reduction in time permits the study of transient species, or by "time-averaging" procedures
S/N
may be improved without the expenditure of inordinate amounts of time. The FT method finds especially important application in the study of NMR spectra of nuclei of low sensitivity and low abundance, such as
13
C.
Thyrotropin Releasing Hormone: Enhancement of Dopa Activity by a Hypothalamic Hormone
Authors: Plotnikoff N. P. , Prange A. J. , Breese G. R. , Anderson M. S. , Wilson I. C.
Published: October 2006

Thyrotropin releasing hormone potentiates the behavioral effects of dopa plus pargyline in mice. Because the potentiation occurs in hypophysectomized mice, as well as in normal mice, the phenomenon is independent of the release of thyroid stimulating hormone from the pituitary. Possible mechanisms and clinical implications are discussed.
Ionospheric Effects on the Transmission of Ultralow-Frequency Plasma Waves
Authors: Lanzerotti L. J. , Lie H. P. , Tartaglia N. A.
Published: October 2006

Measurements of magnetospheric ultralow-frequency plasma waves (period τ, ∼ 18 to 150 seconds) on the ground under continuous daylight conditions in the Antarctic and under alternate day-night solar illumination at the conjugate station in Quebec indicate a significant local time dependence in the transmission properties of the ionosphere for waves of these periods. When the Antarctic station is compared with the Quebec station, the tilt (with respect to the ionosphere) of the orientation plane of the waves is observed to be larger at local noon than at local night.
Regulation of Testis Function in Golden Hamsters: A Circadian Clock Measures Photoperiodic Time
Authors: Elliott Jeffrey A. , Stetson Milton H. , Menaker Michael
Published: October 2006

The photoperiodic testicular response of adult golden hamsters was examined by the use of a 6-hour light period coupled with dark periods of 18, 30, 42, and 54 hours. Cycle lengths of 24 and 48 hours resulted in testicular regression, whereas testicular weight was maintained by cycle lengths of 36 and 60 hours. Our data demonstrate a circadian rhythm of sensitivity to the effects of light on the photoperiodic testicular response of the hamster. The position of light relative to the circadian system (as measured by the locomotor rhythm) is critical in the response.
Galilean Satellites: Identification of Water Frost
Authors: Pilcher Carl B. , Ridgway Stephen T. , McCord Thomas B.
Published: October 2006

Water frost absorptions have been detected in the infrared reflectivities of Jupiter's Galilean satellites JII (Europa) and JIII (Ganymede). We have determined the percentage of frost-covered surface area to be 50 to 100 percent for JII, 20 to 65 percent for JIII, and possibly 5 to 25 percent for JIV (Callisto). The leading side of JIII has 20 percent more frost cover than the trailing side, which explains the visible geometric albedo differences between the two sides. The reflectivity of the material underlying the frost on JII, JIII, and JIV resembles that of silicates. The surface of JI (Io) may be covered by frost particles much smaller than those on JII and JIII.
Obsidian Trade Routes in the Mayan Area
Authors: Hammond Norman
Published: October 2006

Obsidian from two sources in highland Guatemala has been found at 23 sites of the Classic Mayan civilization, mainly in the nonvolcanic lowlands to the north. The distribution, together with trade routes suggested by topography and documentary sources, suggests efficient waterborne transport and competition between sources for the lowland market.
Direct Phase Determination from Neutron Diffraction Data of the Structure of Melampodin
Authors: Bernal Ivan , Watkins Steven F.
Published: October 2006

The structure of a large complex molecule, C
21
H
24
O
9
, has been solved directly from neutron diffraction data by using sigma-2 and tangent refinement methods. As a consequence, the neutron diffraction technique must be reevaluated as a possible primary tool for crystal structure determination.
Genital Sensory Field: Enlargement by Estrogen Treatment in Female Rats
Authors: Komisaruk Barry R. , Adler Norman T. , Hutchison John
Published: October 2006

Recordings of neuronal activity in the pudendal, genitofemoral, and pelvic nerves indicate that the sensory fields of these three nerves are the perineum, the caudal abdomen, and the vagino-cervical area and rectum, respectively. The sensory field of the pudendal nerve was significantly larger in estrogen-treated ovariectomized female rats than in uninjected controls. This effect of estrogen was not mediated by pudendal efferents.
Growth Hormone Responses to L-Dopa in Depressed Patients
Authors: Sachar Edward J. , Mushrush Grace , Perlow Mark , Weitzman Elliot D. , Sassin Jon
Published: October 2006

Plasma human growth hormone responses to oral administration of 500 milligrams of L-dopa were analyzed in three groups of subjects: normals, age 20 to 32; normals, age 48 to 68; and unipolar depressed patients, age 45 to 68. While only 7 percent of the young normals had deficient human growth hormone responses to this stimulus, 36 percent of the older normals and 77 percent of the depressed patients failed to have adequate responses, suggesting an effect of age and a further effect of depressive illness. Because the release of human growth hormone appears to be closely related to brain catecholamine metabolism, the deficient responses in the depressed patients may provide further support to the concept of a neurochemical defect in depressive illness.
Source Parameters for Stick-Slip and for Earthquakes
Authors: Johnson Tracy , Wu Francis T. , Scholz Christopher H.
Published: October 2006

Source parameters of stick-slip friction events measured in the laboratory show particle and rupture propagation velocities which are similar to those observed for earthquakes and inferred from seismic source theory. This dynamic similarity strongly supports the idea that stick-slip is the mechanism for shallow earthquakes.
Rickettsia-like Bacterium Associated with Pierce's Disease of Grapes
Authors: Hopkins Donald L. , Mollenhauer Hilton H.
Published: October 2006

A pleomorphic bacterium was observed by electron microscopy in grape plants infected with Pierce's disease. The organism was located in xylem tissue, and its occurrence was closely associated with symptoms of Pierce's disease. The bacterium resembled a rickettsia in morphology, in its failure to grow on cell-free media, and in its sensitivity to tetracycline antibiotics.
Carnitine Deficiency of Human Skeletal Muscle with Associated Lipid Storage Myopathy: A New Syndrome
Authors: Engel Andrew G. , Angelini Corrado
Published: October 2006

In a rare myopathy muscle fibers contained myriad lipid-filled vacuoles. Homogenates of the patient's muscle oxidized fatty acids more slowly than normal (11 controls). Addition of carnitine increased the oxidation rate with the patient's muscle to the level attained by the controls with carnitine. In five separate muscle samples from the patient the mean carnitine level was less than 20 percent of that observed in 42 controls. Carnitine palmityl transferase and palmityl thiokinase levels in the patient's muscles were not depressed. The present case represents the first recognized instance of carnitine deficiency in human skeletal muscle.
Lunar Permafrost: Dielectric Identification
Authors: Alvarez Román
Published: October 2006

A simulator of lunar permafrost at 100°K exhibits a dielectric relaxation centered at approximately 300 hertz. If permafrost exists in the moon between 100° and 213°K it should present a relaxation peak at approximately 300 hertz. For temperatures up to 263°K it may go up to 20 kilohertz.
Neural Properties of Cultured Human Endocrine Tumor Cells of Proposed Neural Crest Origin
Authors: Tischler Arthur S. , Dichter Marc A. , Biales Bernard , DeLellis Ronald A. , Wolfe Hubert
Published: October 2006

Cells from human endocrine tumors of proposed neural crest origin—five pheochromocytomas, two medullary carcinomas of the thyroid, and two bronchial carcinoids—were grown in monolayer culture. Cells from all nine tumors, including epithelial forms of medullary carcinoma of the thyroid and bronchial carcinoid cells, and epithelial and neuron-like pheochromocytoma cells demonstrated all-or-nothing, short-duration action potentials.
Multiphasic Retention Deficits at Periodic Intervals after Passive-Avoidance Learning
Authors: Holloway Frank A. , Wansley Richard
Published: October 2006

After one-trial passive-avoidance training, independent groups of rats tested promptly after training or at successive 6-hour intervals displayed a repetitive pattern of high then low retention scores. These results suggest that some physiological rhythm may interact with retention performance.
26-Hydroxyecdysone: New Insect Molting Hormone from the Egg of the Tobacco Hornworm
Authors: Kaplanis J. N. , Robbins W. E. , Thompson M. J. , Dutky S. R.
Published: October 2006

Five kilograms of tobacco hornworm eggs (48 to 64 hours old) afforded 26.5 milligrams of a new crystalline insect molting hormone identified as 26-hydroxyecdysone. The three known insect ecdysones—α-ecdysone, 20-hydroxyecdysone, and 20,26-dihydroxyecdysone—were also present but in much smaller quantities. The new hormone is the predominant molting hormone in the hornworm during this stage of embryonic development. These results taken in context with the current knowledge of the chemistry and biochemistry of the molting hormones during postembryonic development in the hornworm indicate quantitative and qualitative differences in the biosynthetic-metabolic pathways as well as in the ecdysones in different developmental stages of this insect.
A Low-Temperature Thermal Process for the Decomposition of Water
Authors: Abraham Bernard M. , Schreiner Felix
Published: October 2006

The following three reactions, each of which has been shown to proceed at the temperature indicated above the arrow, are suggested as a cycle for the thermal decomposition of water:

LiNO
2
+ I
2
+ H
2
O 300°K → LiNO
3
+ 2HI

2HI 700°K → I
2
+ H
2

LiNO
3
750°K → LiNO
2
+ ½O
2
Acquisition and Testing of Gestural Signs in Four Young Chimpanzees
Authors: Fouts Roger S.
Published: October 2006

Two male and two female chimpanzees were each taught ten signs of American Sign Language. The acquisition rates of the signs were compared on the basis of the number of minutes required in training to reach a criterion of five consecutive unprompted correct responses. After the ten signs had been acquired, the chimpanzees were tested in a double-blind procedure for nine of the signs. All four chimpanzees acquired all of the signs. Some signs were consistently easier to acquire than others, and individual differences between the four chimpanzees were found in the acquisition rates and tests.
Water Vapor from a Lunar Breccia: Implications for Evolving Planetary Atmospheres
Authors: Cadenhead D. A. , Buergel W. G.
Published: October 2006

The exposure of a typical complex lunar breccia to hydrogen after a thorough outgassing produces a fully reduced surface state. Subsequent outgassing over a wide temperature range results in the production of water vapor formed from the chemisorbed hydrogen and oxygen from the lunar sample; the proposed mechanism has been confirmed in terms of the chemisorption of deuterium and the release of heavy water. Since the conditions of the experiments are consistent with those on the lunar surface, it is postulated that water vapor will be produced on the moon through the interaction of the solar wind with lunar soil. It is also proposed that such a process could play an important role in the early history of many planets where an oxygen-rich soil is exposed to a reducing atmosphere.
Masking in Visual Recognition: Effects of Two-Dimensional Filtered Noise
Authors: Harmon Leon D. , Julesz Bela
Published: October 2006

It is difficult to recognize portraits that have been coarsely sampled and quantized. Blurring such images improves recognition. A simple, straightforward explanation is that high-frequency noise introduced by the sampling and quantizing must be removed by low-pass filtering to improve the signal-to-noise ratio and hence signal detectability or recognition. Experiments reported here, suggested on the basis of a different model, show instead that noise bands that are spectrally adjacent to the picture's spectrum are considerably more effective in suppressing recognition.
Polonium Radiohalos: An Alternate Interpretation
Authors: Moazed Cyrus , Spector Richard M. , Ward Richard F.
Published: October 2006

A study of the sizes of so-called polonium radiohalos of various types found in biotite from Bancroft, Ontario, has been carried out. The evidence is consistent with the interpretation that these halos are variants of the standard uranium halos. A review of the literature indicates that there is no firm evidence that polonium halos exist, all evidence being equally consistent with the interpretation that these are uranium halos.
Fossil Parasitic Copepods from a Lower Cretaceous Fish
Authors: Cressey Roger , Patterson Colin
Published: October 2006

Well-preserved Lower Cretaceous fossil copepods related to the superfamily Dichelesthioidea have been collected from the gill chamber of the ichthyodectid fish
Cladocyclus gardneri
. The fossils provide conclusive evidence supporting recent theories that link caligid copepods, which are parasitic on fish, to the invertebrate-associated siphonostomes. This is the first discovery of fossil parasitic copepods, and they are by far the oldest copepods of any sort known.
Phase Transitions and Heterogeneity in Lipid Bilayers
Authors: Pagano R. E. , Cherry R. J. , Chapman D.
Published: October 2006

The optical reflectivity of several well-characterized lipid bilayer systems has been correlated with calorimetric studies of the membrane components. There is a large increase in mean membrane thickness when a bilayer is cooled below the transition temperature of the membrane lipid. Similar studies on membranes generated from a mixture of two lipids possessing different degrees of unsaturation suggest that between the characteristic transition temperatures of the two lipids, the bilayer contains clusters of gel and liquid crystalline lipid which coexist within the plane of the membrane.
Growth Retardation in Young Mice Treated with
dl
-Methadone
Authors: Crofford M. , Smith A. A.
Published: October 2006

Newborn mice injected daily for 6 weeks with
dl
-methadone in dosages of 2 to 8 milligrams per kilogram grew significantly more slowly than their saline-treated littermates. Litters given
d
-methadone, 4 milligrams per kilogram, grew normally. Concomitant treatment with naloxone, 10 milligrams per kilogram, prevented growth inhibition. A weight deficit persisted in mice observed 6 weeks after cessation of methadone treatment.
Gas Chromatographic Assay of Epoxide Hydrase Activity with 3-Methylcholanthrene-11,12-Oxide
Authors: Stoming T. A. , Bresnick Edward
Published: October 2006

Epoxide hydrase has been measured in rat tissue with 3-methylcholanthrene-11,12-oxide as substrate; diol formation was assayed by gas chromatographic separation of the trimethylsilylated derivative of trans-11,12-dihydro-11,12-dihydroxy-3-methylcholanthrene from the corresponding derivative of the 11 (or 12)-hydroxy-3-methylcholanthrene on 3 percent OV-17, which is formed from the 11,12-oxide during the derivatization. The polycyclic hydrocarbons were extracted initially from the incubation mixture with ethyl acetate. The assay is simple, inexpensive, and sensitive.
Power, Fresh Water, and Food from Cold, Deep Sea Water
Authors: Othmer Donald F. , Roels Oswald A.
Published: October 2006

Many times more solar heat energy accumulates in the vast volume of warm tropic seas than that produced by all of our power plants. The looming energy crisis causes a renewal of interest in utilizing this stored solar heat to give, in addition to electric power, vast quantities of fresh water. Warm surface water, when evaporated, generates steam, to power a turbine, then fresh water when the steam is condensed by the cold water.

A great increase in revenues over that from power and fresh water is shown by a substantial mariculture pilot plant. Deep sea water contains large quantities of nutrients. These feed algae which feed shellfish, ultimately shrimps and lobsters, in shallow ponds. Wastes grow seaweed of value; and combined revenues from desalination, power generation, and mariculture will give substantial profit.
Copulation in Castrated Male Rats following Combined Treatment with Estradiol and Dihydrotestosterone
Authors: Baum Michael J. , Vreeburg J. T. M.
Published: October 2006

Castrated male rats injected daily with 2 micrograms of estradiol benzoate (EB) combined with 200 micrograms of dihydrotestosterone propionate (DHTP) displayed masculine mating behavior which was indistinguishable from that of other castrates treated with 200 micrograms of testosterone propionate (TP). Significantly less copulation was seen in rats treated with either 4 micrograms of TP plus 200 micrograms of DHTP or 2 micrograms of EB. Mating in male rats may depend on the action of both estrogenic and 5α-dihydro metabolites of testosterone.
Experimental Alcoholic Hepatitis: A New Primate Model
Authors: Rubin Emanuel , Lieber Charles S.
Published: October 2006

Research into the pathogenesis of alcoholic cirrhosis has suffered from the lack of an animal model of alcoholic hepatitis, considered by many to be the link between alcoholic fatty liver and cirrhosis. The entire constellation of histologic features characteristic of alcoholic hepatitis has been produced for the first time in baboons by administration of ethanol with a nutritionally adequate diet. This includes fat, necrosis. inflammation, alcoholic hyaline, fibrosis, and central hyaline sclerosis.
Muscle Carnitine Palmityltransferase Deficiency and Myoglobinuria
Authors: DiMauro Salvatore , DiMauro Paola M. Melis
Published: October 2006

Muscle carnitine palmityltransferase activity, measured by three different methods, was very low (0 to 20 percent of controls) in a patient with a familial syndrome of recurrent myoglobinuria. Long-chain fatty acyl CoA synthetase activity was normal; acetylcarnitine transferase activity was decreased by 40 percent, and carnitine content was 1.7 times higher than the mean control value. Utilization of palmitate by isolated mitochondria was more impaired than utilization of palmitylcarnitine, suggesting a more severe defect of carnitine palmityltransferase I than transferase II. Thus, myoglobinuria may be due to a genetic defect of lipid metabolism in skeletal muscle.
Transovarial Transmission of LaCrosse Virus (California Encephalitis Group) in the Mosquito,
Aedes triseriatus
Authors: Watts D. M. , Pantuwatana S. , DeFoliart G. R. , Yuill T. M. , Thompson W. H.
Published: October 2006

LaCrosse virus (California encephalitis group) was recovered from F
1
eggs, larvae, and adults produced by experimentally infected
Aedes triseriatus
. The F
1
females transmitted the virus by bite to suckling mice and chipmunks. This, plus isolations of LaCrosse virus from larvae collected from their natural habitats in enzootic areas and from males and females reared from them, suggests that transovarial transmission is the overwintering mechanism for this arbovirus in northern United States.
Disposal of Nuclear Wastes
Authors: Kubo Arthur S. , Rose David J.
Published: October 2006

For the present and the foreseeable future the following options appear to be either usable or worth further exploration: mausolea; disposal in mines of various sorts, and perhaps in ice; in situ melt; and further chemical separations. The options are interdependent.

It is too early to assess disposal in space, and disposal in the oceans remains unsafe for lack of adequate knowledge. Table 3 is a summary of the main ideas for which we have worked out (sometimes uncertain) costs.

For the short term, ultimate disposal in deep mines is the best-developed plan. However, the related concept of in situ melt has significant advantages and should be realistically appraised. Further chemical separation with subsequent recycling of the actinides in a LMFBR should be investigated and implemented, for it would be universally beneficial; on the other hand, additional removal of strontium and cesium does not seem attractive. Thus, for the near future we make the following recommendations:

1) Provide temporary storage facilities to ensure that the projected commercial high-level wastes do not become a public hazard. The AEC adopts this view, and has stated an intention to construct such facilities. But because of the capriciousness of man and nature, a workable ultimate disposal scheme must be developed soon.

2) Fund other ultimate disposal schemes at the same rate as the salt mine project—say $1 million a year or more—to sharpen the technological issues, so that a decision can be reached in the next few years. The schemes should include (i) in situ melt, and the variation with a central repository; (ii) burial in mines other than salt mines (including Antarctic rocks and permanent ice); (iii) further chemical separation of actinides and recycling actinides in a LMFBR.

3) Maintain liaison with the developing space shuttle technology to insure that no opportunity is lost.

The AEC has a commitment to hold safety foremost in its waste management program, but budget considerations and management priorities have downgraded the program. Past funding levels and management emphasis have yet to produce, after a decade and a half, one operational long-term storage facility—a sign of both commendable caution and inadequate work. If nuclear power is to resolve our energy needs in the coming decades, its benefits should not be delayed for lack of a viable management program for high-level wastes.
The Colossi of Memnon Revisited
Authors: Heizer R. F. , Stross F. , Hester T. R. , Albee A. , Perlman I. , Asaro F. , Bowman H.
Published: October 2006

The only areas that are likely to have furnished the original stone for the Colossi of Memnon are near Cairo (Gebel el Ahmar), Aswan, and possibly Silsileh. Neutron activation analysis of samples from the colossi shows them to be distinctly different from samples obtained from the three known quarries near Aswan and from the quarries near Silsileh and Edfu, but very similar to samples obtained from Gebel el Ahmar. Petrographic analysis of colossi and quarry samples also provides strong evidence that the colossi came from Gebel el Ahmar.

The blocks used by the engineers of Septimius Severus to reconstruct the north colossus were shown by neutron activation analysis to have originated from a deposit other than Gebel el Ahmar. The composition of these blocks conformed with samples taken from the quarries 8 and 9 km north of Edfu (the quartzite deposit closest to Thebes) and from the Aswan quarries. Petrographic analysis associated these reconstruction blocks with Edfu but not with Aswan.

Neutron activation analysis of other artifacts in the area of the colossi indicates that they also came from Cairo rather than Aswan.
Neonate Movement Is Synchronized with Adult Speech: Interactional Participation and Language Acquisition
Authors: Condon William S. , Sander Louis W.
Published: October 2006

As early as the first day of life, the human neonate moves in precise and sustained segments of movement that are synchronous with the articulated structure of adult speech. These observations suggest a view of development of the infant as a participant at the outset in multiple forms of interactional organization, rather than as an isolate.
Neurons in Rhesus Monkey Visual Cortex: Systematic Relation between Time of Origin and Eventual Disposition
Authors: Rakic Pasko
Published: October 2006

Autoradiographic evidence after injection of tritiated thymidine indicates that cell position in the laminae of the monkey visual cortex is systematically related to time of cell origin. The earliest-formed neurons, destined for the deepest stratum, arise at about embryonic day 45, and the last ones, destined for the outermost cell stratum, form at about day 102; cells of intervening layers are generated at intervening times. No neocortical neurons are produced in the last two prenatal months or after birth. Compared to cortical neurons in rodents, those in the monkey arise earlier, and the "inside-out" relation of cell position to time of origin is more rigid.
Mapping Human Autosomes: Evidence Supporting Assignment of Rhesus to the Short Arm of Chromosome No. 1
Authors: Marsh W. L. , Chaganti R. S. K. , Gardner Frank H. , Mayer Klaus , Nowell Peter C. , German James
Published: October 2006

Rh-negative erythrocytes were found in the blood of an Rh-positive man suffering from myelofibrosis. Nucleated hemopoietic precursors were also circulating in his blood, and these cells had an abnormal chromosome complement from which identifiable chromosome segments had been deleted. Correlation of the serological and cytogenetic findings, combined with previous data, indicates that the Rhesus blood group locus is on the distal portion of the short arm of chromosome No. 1.
Mercury: Does Its Atmosphere Contain Water?
Authors: Thomas Gary E.
Published: October 2006

The atmosphere of Mercury, like that of the moon, is maintained in an extremely tenuous minimum state by weak solar wind accretion and radioactive decay processes, and depleted by strong removal mechanisms. Unlike the moon, it has a high daytime surface temperature that promotes the production of water vapor, which may be the dominant atmospheric constituent derived from solar wind protons.
Orientation of Homing Pigeons Altered by a Change in the Direction of an Applied Magnetic Field
Authors: Walcott Charles , Green Robert P.
Published: October 2006

Homing pigeons were equipped with a pair of small coils around their heads. Birds with an induced field of 0.6 gauss and the south magnetic pole up, oriented toward home normally under both sun and overcast. Birds with the polarity reversed oriented toward home when the sun was visible but often flew away from home under overcast.
Temporal Summation of Light by a Vertebrate Visual Receptor
Authors: Hood Donald C. , Grover Barry G.
Published: October 2006

Using aspartate to isolate mass receptor activity, we have investigated the reciprocity of flash intensity and flash duration in determining the response of the frog's cone receptor. The durations over which reciprocity holds decrease with increases in either flash energy or ambient light intensity. These findings parallel those of human psychophysical experiments.
Selective Destruction of the Pigmented Epithelium in the Ciliary Body of the Eye
Authors: Okisaka Shigekuni , Kuwabara Toichiro , Rapoport Stanley I.
Published: October 2006

Perfusion of the internal carotid artery with hypertonic solution selectively destroys most of the pigmented epithelium of the ciliary body of the monkey eye, converts fenestrated endothelium of capillaries to continuous endothelium, and transiently breaks down the blood-aqueous barrier. The nonpigmented epithelium regenerates and the intraocular pressure returns to normal even though the pigmented epithelium is permanently destroyed.
Structure and Functional Expression of a Human Interleukin-8 Receptor
Authors: Holmes William E. , Lee James , Kuang Wun-Jing , Rice Glenn C. , Wood William I.
Published: October 2006

Interleukin-8 (IL-8) is a member of a family of pro-inflammatory cytokines. Although the best characterized activities of IL-8 include the chemoattraction and activation of neutrophils, other members of this family have a wide range of specific actions including the chemotaxis and activation of monocytes, the selective chemotaxis of memory T cells, the inhibition of hematopoietic stem cell proliferation, and the induction of neutrophil infiltration in vivo. A complementary DNA encoding the IL-8 receptor from human neutrophils has now been isolated. The amino acid sequence shows that the receptor is a member of the superfamily of receptors that couple to guanine nucleotide binding proteins (G proteins). The sequence is 29% identical to that of receptors for the other neutrophil chemoattractants, fMet-Leu-Phe and C5a. Mammalian cells transfected with the IL-8 receptor cDNA clone bind IL-8 with high affinity and respond specifically to IL-8 by transiently mobilizing calcium. The IL-8 receptor may be part of a subfamily of related G protein-coupled receptors that transduce signals for the IL-8 family of pro-inflammatory cytokines.
African Populations and the Evolution of Human Mitochondrial DNA
Authors: Vigilant Linda , Stoneking Mark , Harpending Henry , Hawkes Kristen , Wilson Allan C.
Published: October 2006

The proposal that all mitochondrial DNA (mtDNA) types in contemporary humans stem from a common ancestor present in an African population some 200,000 years ago has attracted much attention. To study this proposal further, two hypervariable segments of mtDNA were sequenced from 189 people of diverse geographic origin, including 121 native Africans. Geographic specificity was observed in that identical mtDNA types are shared within but not between populations. A tree relating these mtDNA sequences to one another and to a chimpanzee sequence has many deep branches leading exclusively to African mtDNAs. An African origin for human mtDNA is supported by two statistical tests. With the use of the chimpanzee and human sequences to calibrate the rate of mtDNA evolution, the age of the common human mtDNA ancestor is placed between 166,000 and 249,000 years. These results thus support and extend the African origin hypothesis of human mtDNA evolution.
Mercury's Atmosphere from Mariner 10: Preliminary Results
Authors: Broadfoot A. L. , Kumar S. , Belton M. J. S. , McElroy M. B.
Published: October 2006

Analysis of data obtained by the ultraviolet experiment on Mariner 10 indicates that Mercury is surrounded by a thin atmosphere consisting in part of helium. The partial pressure of helium at the terminator is about 5 × 10
-12
millibar. The total surface pressure of the atmosphere is less than about 2 × 10
-9
millibar. Upper limits are set for the abundance of various gases, including hydrogen, oxygen, carbon, argon, neon, and xenon. The wavelength dependence of Mercury's surface albedo is similar to that of the moon over a broad range of wavelengths from 500 to 1600 angstroms. Strong signals were recorded by the airglow instrument as Mariner 10 passed through the cavity behind Mercury. They are as yet unexplained but may provide information on the properties of the local plasma.
Mercury's Surface: Preliminary Description and Interpretation from Mariner 10 Pictures
Authors: Murray Bruce C. , Belton Michael J. S. , Danielson G. Edward , Davies Merton E. , Gault Donald E. , Hapke Bruce , O'Leary Brian , Strom Robert G. , Suomi Verner , Trask Newell
Published: October 2006

The surface morphology and optical properties of Mercury resemble those of the moon in remarkable detail and record a very similar sequence of events. Chemical and mineralogical similarity of the outer layers of Mercury and the moon is implied; Mercury is probably a differentiated planet with a large iron-rich core. Differentiation is inferred to have occurred very early. No evidence of atmospheric modification of landforms has been found. Large-scale scarps and ridges unlike lunar or martian features may reflect a unique period of planetary compression near the end of heavy bombardment by small planetesimals.
Dedifferentiated Guard Cells in Magnoliaceous Leaves
Authors: Tucker Shirley C.
Published: October 2006

Evidence has been obtained that guard cells and other epidermal cells as well as mesophyll cells undergo division during wound repair of mature leaves in 26 magnoliaceous taxa in the genera
Kmeria
,
Elmerrillia
,
Magnolia
,
Manglietia
,
Michelia
,
Paramichelia
, and
Talauma
. Division of epidermal cells is believed to be rare in mature leaves, and division of guard cells is particularly unusual in most species previously studied.
Toxicity in Sponges and Holothurians: A Geographic Pattern
Authors: Bakus Gerald J. , Green Gerardo
Published: October 2006

Toxicity in sponges and holothurians is inversely related to latitude and may reach 100 percent for holothurians in high-diversity coral reefs. Evidence from approximately 700 experiments and from underwater observations suggests that predation by fish has resulted in natural selection for noxious and toxic chemical compounds in species within these taxa.
Messenger RNA Splicing in Yeast: Clues to Why the Spliceosome Is a Ribonucleoprotein
Authors: Guthrie Christine
Published: October 2006

The removal of introns from eukaryotic messenger RNA precursors shares mechanistic characteristics with the self-splicing of certain introns, prompting speculation that the catalytic reactions of nuclear pre-messenger RNA splicing are fundamentally RNA-based. The participation of five small nuclear RNAs (snRNAs) in splicing is now well documented. Genetic analysis in yeast has revealed the requirement, in addition, for several dozen proteins. Some of these are tightly bound to snRNAs to form small nuclear ribonucleoproteins (snRNPs); such proteins may promote interactions between snRNAs or between an snRNA and the intron. Other, non-snRNP proteins appear to associate transiently with the spliceosome. Some of these factors, which include RNA-dependent adenosine triphosphatases, may promote the accurate recognition of introns.
Solution Structures of β Peptide and Its Constituent Fragments: Relation to Amyloid Deposition
Authors: Barrow Colin J. , Zagorski Michael G.
Published: October 2006

The secondary structures in solution of the synthetic, naturally occurring, amyloid β peptides, residues 1 to 42 [β(1-42)] and β(1-39), and related fragments, β(1-28) and β(29-42), have been studied by circular dichroism and two-dimensional nuclear magnetic resonance spectroscopy. In patients with Alzheimer's disease, extracellular amyloid plaque core is primarily composed of β(1-42), whereas cerebrovascular amyloid contains the more soluble β(1-39). In aqueous trifluoroethanol solution, the β(1-28), β(1-39), and β(1-42) peptides adopt monomeric α-helical structures at both low and high pH, whereas at intermediate pH (4 to 7) an oligomeric β structure (the probable structure in plaques) predominates. Thus, β peptide is not by itself an insoluble protein (as originally thought), and localized or normal age-related alterations of pH may be necessary for the self-assembly and deposition of β peptide. The hydrophobic carboxyl-terminal segment, β(29-42), exists exclusively as an oligomeric β sheet in solution, regardless of differences in solvent, pH, or temperature, suggesting that this segment directs the folding of the complete β(1-42) peptide to produce the β-pleated sheet found in amyloid plaques.
A Component of Calcium-activated Potassium Channels Encoded by the
Drosophila slo
Locus
Authors: Atkinson Nigel S. , Robertson Gail A. , Ganetzky Barry
Published: October 2006

Calcium-activated potassium channels mediate many biologically important functions in electrically excitable cells. Despite recent progress in the molecular analysis of voltage-activated K
+
channels, Ca
2+
-activated K
+
channels have not been similarly characterized. The
Drosophila
slowpoke
(
slo
) locus, mutations of which specifically abolish a Ca
2+
-activated K
+
current in muscles and neurons, provides an opportunity for molecular characterization of these channels. Genomic and complementary DNA clones from the
slo
locus were isolated and sequenced. The polypeptide predicted by
slo
is similar to voltage-activated K
+
channel polypeptides in discrete domains known to be essential for function. Thus, these results indicate that
slo
encodes a structural component of Ca
2+
-activated K
+
channels.
Protein Kinase Activity Closely Associated with a Reconstituted Calcium-Activated Potassium Channel
Authors: Chung Sungkwon , Reinhart Peter H. , Martin Bruce L. , Brautigan David , Levitan Irwin B.
Published: October 2006

Modulation of the activity of potassium and other ion channels is an essential feature of nervous system function. The open probability of a large conductance Ca
2+
-activated K
+
channel from rat brain, incorporated into planar lipid bilayers, is increased by the addition of adenosine triphosphate (ATP) to the cytoplasmic side of the channel. This modulation takes place without the addition of protein kinase, requires Mg
2+
, and is mimicked by an ATP analog that serves as a substrate for protein kinases but not by a nonhydrolyzable ATP analog. Addition of protein phosphatase 1 reverses the modulation by MgATP. Thus, there may be an endogenous protein kinase activity firmly associated with this K
+
channel. Some ion channels may exist in a complex that contains regulatory protein kinases and phosphatases.
Synthesis of Cell Wall Microfibrils in vitro by a "Soluble" Chitin Synthetase from
Mucor rouxii
Authors: Ruiz-Herrera J. , Bartnicki-Garcia S.
Published: October 2006

A "soluble" form of chitin synthetase was separated from a membrane-rich fraction by exposure to the enzyme substrate (uridine diphosphate
N
-acetyl-D-glucosamine) and activator (
N
-acetyl-D-glucosamine). The solubilized enzyme catalyzed the synthesis of chitin microfibrils similar, if not identical, to those formed in vivo by the fungus. Cell wall microfibrils were thus abundantly formed in the absence of a living cell or its membranes.
Circadian Oscillations in Rodents: A Systematic Increase of Their Frequency with Age
Authors: Pittendrigh Colin S. , Daan Serge
Published: October 2006

The circadian activity rhythms of golden hamsters and two species of deermouse, when released from a light-dark cycle of 12 hours light and 12 hours of darkness into constant darkness, had progressively shorter periods as the animals became older. A possible bearing of this fact on the aging process is briefly outlined.
Single Cell Layered Heart: Electromechanical Properties of the Heart of
Boltenia ovifera
Authors: Weiss James , Morad Martin
Published: October 2006

The heart of
Boltenia ovifera
(the sea potato) is a tubular structure formed by a single layer of myocardial cells. Electron microscopic studies show that each cell contains a single myofibril located adjacent to the luminal surface of the cell. Electrical and mechanical measurement of a cannulated perfused heart demonstrate that only the luminal membrane is excitable and elicits contraction on depolarization. Calcium and magnesium exert antagonistic effects on tension, and potassium depolarizes the myocardium and produces contractures when the luminal membrane is exposed to various concentrations of these ions. The extraluminal membrane does not respond electrically or mechanically to calcium, magnesium, or potassium, and its potential seems to be effectively "clamped" by the luminal membrane. Functionally, therefore, this heart consists of a single active membrane with the adjacent contractile apparatus.
Methanol as a Gasoline Extender: A Critique
Authors: Wigg E. E.
Published: October 2006

The tests conducted with the three vehicles at different emission control levels suggest that, in the area of fuel economy and emissions, potential benefits with methanol blends are related to carburetion and are only significant in the case of the rich-operating cars built before emission control standards were imposed. Theoretical considerations related to methanol's leaning effect on carburetion support this conclusion. Potential advantages for methanol in these areas are therefore continuously diminishing as the older cars leave the roads. At present, these older cars use only about one-fourth of the total motor gasoline consumed and, before methanol could be used on a large scale, this fraction would be much smaller.

The use of methanol in gasoline would almost certainly create severe product quality problems. Water contamination could lead to phase separation in the distribution system and possibly in the car tank as well, and this would require additional investment in fuel handling and blending equipment. Excess fuel volatility in hot weather may also have adverse effects on car performance if the methanol blends include typical concentrations of butanes and pentanes. Removal of these light hydrocarbon components would detract from methanol's role as a gasoline extender and if current fuel volatility specifications were maintained, its use could lead to a net loss in the total available energy for use in motor fuels. Car performance problems associated with excessively lean operation would also be expected in the case of a significant proportion of late-model cars which are adjusted to operate on lean fuel-air mixtures.

If methanol does become available in large quantities, these factors suggest that it would be more practical to use it for purposes other than those related to the extending of motor gasoline, such as for gas turbines used for electric power generation. In this case, the "pure" methanol would act as a clean-burning fuel, having none of the potentially severe product quality problems associated with its use in motor gasoline, while the fuel oil or natural gas currently burned in these turbines could be diverted to other uses.
Tandem Calling: A New Kind of Signal in Ant Communication
Authors: Mglich M. , Maschwitz U. , Hlldobler B.
Published: October 2006

Leptothorax acervorum
,
L. muscorum
, and
L. nylanderi
recruit nest mates to a new food source by tandem running, with only one nest mate being recruited at a time. This technique is initiated by a special "tandem calling" behavior; the recruiter slants its gaster upward and discharges poison gland secretions from the extruded sting. Nest mates are attracted, and as soon as one of them touches the calling ant, tandem running starts. Further details of the full recruitment sequence are provided. Evidence is presented to suggest that tandem running is the evolutionary precursor of odor-trail communication and sex attraction within certain phylogenetic lines of myrmicine ants.
Skin Carcinogenesis: Cholesterol-5α,6α-Epoxide Hydrase Activity in Mouse Skin Irradiated with Ultraviolet Light
Authors: Chan Jarvis T. , Black Homer S.
Published: October 2006

Cholesterol-5α,6α-epoxide hydrase activity was 96 percent greater in skin of hairless mice that were receiving suberythemic ultraviolet light irradiation for 15 weeks than in nonirradiated controls. This enzyme system, which metabolizes cholesterol-5α,6α-epoxide (a known carcinogen), appears to be substrateinducible and is apparently responsible for the concomitant reduction of the sterol carcinogen that occurs prior to tumor induction.
β-Adrenergic Receptor: Stereospecific Interaction of Iodinated β-Blocking Agent with High Affinity Site
Authors: Aurbach G. D. , Fedak S. A. , Woodard C. J. , Palmer J. S. , Hauser D. , Troxler F.
Published: October 2006

An iodine-labeled β-adrenergic inhibitor (
125
l-hydroxybenzylpindolol) binds specifically to a site on turkey erythrocyte membranes. A series of β-adrenergic agonists and inhibitors compete for this binding site, with apparent affinities paralleling biological effectiveness as activators or inhibitors of catecholaminestimulated adenylate cyclase. The activity of d-(+) agonists or inhibitors was 1 percent (or less) than that of the corresponding l-(-) isomers in competing for binding of the iodinated blocker as well as in affecting catecholamine-stimulated adenylate cyclase. 1-(-)-Norepinephrine was about one-tenth as active as l-(-)-isoproterenol in competing for the β-blocking agent site. The stereospecificity of the interaction with the iodinated β-blocking agent and the correspondence between affinity for site and biological potency of analogs suggested that this interaction is involved in function of the β-adrenergic receptor.