bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Therapy of Human Glioma by Means of a Genetically Engineered Virus Mutant
Authors: Martuza Robert L. , Malick Amy , Markert James M. , Ruffner Katherine L. , Coen Donald M.
Published: October 2006

Malignant gliomas are the most common malignant brain tumors and are almost always fatal. A thymidine kinase-negative mutant of herpes simplex virus-1 (
dl
sptk) that is attenuated for neurovirulence was tested as a possible treatment for gliomas. In cell culture,
dl
sptk killed two long-term human glioma lines and three short-term human glioma cell populations. In nude mice with implanted subcutaneous and subrenal U87 human gliomas, intraneoplastic inoculation of
dl
sptk caused growth inhibition. In nude mice with intracranial U87 gliomas, intraneoplastic inoculation of
dl
sptk prolonged survival. Genetically engineered viruses such as
dl
sptk merit further evaluation as novel antineoplastic agents.
High Concentration of GABA and High Glutamate Decarboxylase Activity in Rat Pancreatic Islets and Human Insulinoma
Authors: Okada Yasuhiro , Taniguchi Hiroshi , Schimada Chicaco
Published: October 2006

The concentration of γ-aminobutyric acid (GABA) and the activity of glutamate decarboxylase (GAD) in rat and human pancreas were measured by sensitive assay methods. The GABA concentration in rat pancreas was 2.51 millimoles per kilogram (dry weight) and GAD activity was 2.58 mmoles per kilogram per hour. The GABA concentration and GAD activity in rat Langerhans' islets were 18.9 mmole kg
-1
and 66.7 mmole kg
-1
hour
-1
, whereas those in the exocrine acini were 1.97 mmole kg
-1
and 4.67 mmole kg
-1
hour
-1
, respectively. In an insulinoma region of human pancreas the GABA concentration was 25.5 mmole kg
-1
and the GAD activity was 138.2 mmole kg
-1
hour
-1
, but in the surrounding nontumor region these values were only 2.81 mmole kg
-1
and 2.01 mmole kg
-1
hour
-1
, respectively, similar to the values in normal rat pancreas.
The C-Fragment of β-Lipotropin: An Endogenous Neuroleptic or Antipsychotogen?
Authors: Jacquet Yasuko F. , Marks Neville
Published: October 2006

Microinjection of the C-fragment (also called β-endorphin), which is amino acid sequence 61-91 of the endogenous pituitary hormone, β-lipotropin (β-LPH), in the periaqueductal gray of the rat resulted in profound sedation and catalepsy, while microinjection of smaller fragments—that is, methionine-enkephalin [sequence β-LPH-(61-65)] and its related pentapeptide, leucine enkephalin, and α-endorphin [sequence β-LPH-(61-76)] resulted in attenuated forms of this behavior. This indicates that the C-fragment is an important neuromodulator of the central nervous system. The similarity of this behavior to that seen after systemic administration to experimental animals of exogenous neuroleptics suggests that a disturbance in the bioavailability of this neuropeptide to receptor sites in brain-perhaps due to lack of enzymatic cleavage from the circulating parent hormone, β-lipotropin—may be an etiological factor in those psychopathological states for which the exogenous neuroleptics exert an ameliorative influence.
Specific Effects of Neurotransmitter Antagonists on Ganglion Cells in Rabbit Retina
Authors: Wyatt Harry J. , Day Nigel W.
Published: October 2006

Directionally sensitive ganglion cells in rabbit retina lose their directional sensitivity when picrotoxin, an antagonist of the inhibitory neurotransmitter γ-aminobutyric acid, is infused into the retinal blood supply. Strychnine, an antagonist of glycine, does not produce this effect. Other receptive field types are affected by strychnine but not picrotoxin. Inhibitory transmitters therefore have specific functions in information processing in the retina.
Deleted HTLV-I Provirus in Blood and Cutaneous Lesions of Patients with Mycosis Fungoides
Authors: Hall William W. , Liu Chunren R. , Schneewind Olaf , Takahashi Hidehiro , Kaplan Mark H. , Röupe Gosta , Vahlne Anders
Published: October 2006

Mycosis fungoides, a rare form of cutaneous T cell leukemia/lymphoma, is suspected of having a viral etiology on the basis of certain similarities to adult T cell leukemia, which is associated with human T cell leukemia/lymphoma virus type I (HTLV-I) infection. Cell lines were established from peripheral blood mononuclear cells (PBMC) of an HTLV-I-seronegative patient with mycosis fungoides. DNA hybridization analysis revealed the presence of HTLV-I-related sequences with unusual restriction endonuclease sites. Sequence analysis of subcloned fragments demonstrated the presence of a monoclonally integrated provirus with a 5.5-kilobase deletion involving large regions of
gag
and
env
and all of
pol
. Additional evidence for the presence of deleted proviruses was found by polymerase chain reaction (PCR) amplification of DNA from cutaneous lesions of five other HTLV-I-seronegative patients. The findings suggest that HTLV-I infection may be involved in the etiology of at least certain cases of mycosis fungoides.
Rod and Cone Pathways in the Inner Plexiform Layer of Cat Retina
Authors: Kolb Helga , Famiglietti E. V.
Published: October 2006

In cat retina, rod bipolar terminals do not synapse on ganglion cells but on two types of amacrine cell (types I and II). Cone bipolars synapse directly on ganglion cells and on type I amacrines. The type II amacrine appears to play a special internuncial role between bipolars and ganglion cells in the rod system.
Isobaric Bubble Growth: A Consequence of Altering Atmospheric Gas
Authors: Strauss Richard H. , Kunkle Thomas D.
Published: October 2006

During certain treatments of decompression sickness following dives made with compressed air, the U.S. Navy advocates breathing helium-oxygen mixtures. However, stable nitrogen bubbles created within gelatin by decompression have been found to enlarge when the atmosphere was switched from nitrogen to helium without changing ambient pressure. This suggests that decompression sickness would be worsened by switching from nitrogen to helium in the breathing gas mixture.
Anomeric Specificity of Glucose-Stimulated Insulin Release: Evidence for a Glucoreceptor?
Authors: Grodsky Gerold M. , Fanska Rudolph , West Lester , Manning Michele
Published: October 2006

The effects on insulin secretion of α and β anomers of D-glucose were studied in the in vitro perfused rat pancreas. Both phases of insulin release showed consistent stereospecificity for α-glucose; this specificity indicates an action of glucose independent of intracellular glucose metabolism.
Clonal Depletion in Neonatal Tolerance
Authors: Khler Heinz , Kaplan David R. , Strayer David S.
Published: October 2006

Specific unresponsiveness can be induced in neonatal and adult BALB/c mice by antibody against antigen-specific receptor (antireceptor antibody). When heterologous antireceptor antibody is used in the indirect fluorescence technique, the number of fluorescent cells in these animals is significantly lower than in normal animals. Fluorescent cells appear after a relatively brief incubation of cells from adult-suppressed animals, whereas no fluorescent cells are detected when cells from neonatally treated animals are incubated briefly. Evidently, treating neonatal mice with antireceptor antibody specifically depletes the antigen-responsive clone. In contrast, antireceptor antibody causes reversible blockade of responsive cells in adult-suppressed animals.
Residential Patterns at Monte Alban, Oaxaca, Mexico
Authors: Winter Marcus C.
Published: October 2006

Monte Alban was founded in period I (about 500 B.C.) probably by households from previously existing villages in the Valley of Oaxaca. There is some evidence for status variation in period I households, but more information is needed to determine its role in the early development of the city. During the millennium or more of urban growth at Monte Alban a change occurred in the organization of household space from an open outward-directed focus to a closed inward-directed one. This was accompanied by a formalization of household and interhousehold space and by a standardization in household sizes and burial treatment reflecting emergence of a social class hierarchy. These changes indicate development from a flexible to a highly structured society, which may be a general trend in urbanization.
Skylab Radar Altimeter: Short-Wavelength Perturbations Detected in Ocean Surface Profiles
Authors: Leitao C. D. , McGoogan J. T.
Published: October 2006

Short-wavelength anomalies in sea surface topography, caused by the gravitational effects of major ocean bottom topographic features, have been detected by the radar altimeter aboard Skylab. Some features, such as deep ocean trenches, seamounts, and escarpments, displace the ocean surface by as much as 15 meters over 100-kilometer wavelengths. This experiment demonstrates the potential of satellite altimetry for determining the ocean geoid and for mapping major features of the ocean bottom.
The 2.3 Angstrom X-Ray Structure of Nitrite Reductase from
Achromobacter cycloclastes
Authors: Godden J. W. , Turley S. , Teller D. C. , Adman E. T. , Liu M. Y. , Payne W. J. , LeGall J.
Published: October 2006

The three-dimensional crystal structure of the copper-containing nitrite reductase (NIR) from
Achromobacter cycloclastes
has been determined to 2.3 angstrom (Å) resolution by isomorphous replacement. The monomer has two Greek key β-barrel domains similar to that of plastocyanin and contains two copper sites. The enzyme is a trimer both in the crystal and in solution. The two copper atoms in the monomer comprise one type I copper site (Cu-I; two His, one Cys, and one Met ligands) and one putative type II copper site (Cu-II; three His and one solvent ligands). Although ligated by adjacent amino acids Cu-I and Cu-II are ∼12.5 Å apart. Cu-II is bound with nearly perfect tetrahedral geometry by residues not within a single monomer, but from each of two monomers of the trimer. The Cu-II site is at the bottom of a 12 Å deep solvent channel and is the site to which the substrate (NO
2
-
) binds, as evidenced by difference density maps of substrate-soaked and native crystals.
Specific Elicitors of Plant Phytoalexin Production: Determinants of Race Specificity in Pathogens?
Authors: Keen N. T.
Published: October 2006

Race 1 cultures of the phytopathogenic fungus Phytophthora megasperma var. sojae produced a specific elicitor of the soybean phytoalexin hydroxyphaseollin that resulted in higher production of the phytoalexin on disease-resistant Harosoy 63 soybeans than in the near-isogenic susceptible cultivar Harosoy. Race 3 of the fungus, which gives susceptible reactions on both soybean cultivars, did not produce the race I specific elicitor.
Deep Seismic Reflection Results from the Gulf of Mexico: Part I
Authors: Watkins Joel S. , Worzel J. Lamar , Houston Mark H. , Ewing Maurice , Sinton John B.
Published: October 2006

Deep sounding seismic reflection data show undeformed reflectors at depths down to 11 kilometers beneath the continental rise and abyssal plain and 7 kilometers in basins of the lower slope. Weak reflectors are visible beneath the salt of the Sigsbee Scarp and within salt ridges separating the lower slope basins.
Identification of Ets- and Notch-Related Subunits in GA Binding Protein
Authors: LaMarco Kelly , Thompson Catherine C. , Byers Brien P. , Walton Eve M. , McKnight Steven L.
Published: October 2006

Recombinant cDNA clones that encode two distinct subunits of the transcription factor GA binding protein (GABP) have been isolated. The predicted amino acid sequence of one subunit, GABPα, exhibits similarity to the sequence of the product of the
ets
-1 protooncogene in a region known to encompass the Ets DNA binding domain. The sequence of the second subunit, GABPβ, contains four 33-amino acid repeats located close to the NH2-terminus of the subunit. The sequences of these repeats are similar to repeats in several transmembrane proteins, including Notch from
Drosophila melanogaster
and Glp-1 and Lin-12 from
Caenorhabditis elegans
. Avid, sequence-specific binding to DNA required the presence of both polypeptides, revealing a conceptual convergence of nuclear transforming proteins and membrane-anchored proteins implicated in developmentally regulated signal transduction processes.
Plant Mycoplasmas: A Cultivable Spiroplasma Causes Corn Stunt Disease
Authors: Williamson D. L. , Whitcomb R. F.
Published: October 2006

A spiroplasma can be isolated and grown continuously in cell-free medium from stunted corn or from Drosophila injected with sap expressed from diseased corn. The organism is serologically related to, but not identical with,
Spiroplasma citri
, the causative agent of citrus stubborn disease. Leafhoppers injected with cultured organisms induced typical symptoms of the corn stunt disease when placed on previously healthy corn plants.
Stratospheric Nitric Oxide: Measurements during Daytime and Sunset
Authors: Burkhardt E. G. , Lambert C. A. , Patel C. K. N.
Published: October 2006

Measurements of the temporal variation in the stratospheric nitric oxide concentration covering a time period from 11:00 to 20:30 local time show the effect of solar ultraviolet sunset. The experimental results strongly support the theorized role of nitric oxide as a catalyst in the destruction of ozone and its importance in the stratospheric ozone balance.
Lunar Gravity: The First Farside Map
Authors: Ferrari Alfred J.
Published: October 2006

A global lunar gravity field has been determined from data on the long-term motion of the Apollo 15 and Apollo 16 subsatellites and Lunar Orbiter 5. The nearside gravity map resolves major mascon basins and, in general, is in excellent agreement with the results of Muller and Sjogren. The farside gravity map is characterized by broad positive gravity in the highland regions with interspersed, localized, negative anomalies corresponding to major ringed basins. A comparison between global gravity and topography indicates that a thicker farside crust could be responsible for these gravitational differences between the two lunar hemispheres.
Picosecond Kinetics of Events Leading to Reaction Center Bacteriochlorophyll Oxidation
Authors: Kaufmann K. J. , Dutton P. L. , Netzel T. L. , Leigh J. S. , Rentzepis P. M.
Published: October 2006

A transient absorption spectrum has been measured in
Rhodopseudomonas spheroides
R26 reaction centers. Its salient features indicate that both the bacteriopheophytin and bacteriochlorophyll chromophores play a role in the excited state. Decay of this state yields a rise time for oxidation of the reaction center complex of about 150 picoseconds.
Water Wells as Possible Indicators of Tectonic Strain
Authors: Wakita Hiroshi
Published: October 2006

Coseismic water level changes associated with the Izu-Hanto-oki earthquake of 9 May 1974 were recorded in 59 among 95 observation wells located in the districts of Tokai and Kanto, Japan. The spatial distribution of wells in which the groundwater level rose or fell is rather systematic. The areas in which these wells are located closely coincide with the areas of contraction and dilatation expected by the faulting. This strongly suggests a possible correlation between the observed changes in groundwater level and the tectonic strain. The results may indicate that the water level of wells is able to monitor at least acute coseismic strain changes.
Electron-Hole Condensation in Semiconductors
Authors: Jeffries Carson D.
Published: October 2006

In Ge and Si, and also in Ge-Si alloys, there is extensive evidence for the stable binding of electrons and holes into a cold plasma of constant density, which undergoes a phase separation. Liquid metallic drops 1 to 300 μm in size are formed, with lifetimes ranging from 0.1 to 600 μsec. For Ge a surprising amount is known: the phase diagram, the surface energy, the work function, the decay kinetics. Much less is known for Si. There is good agreement between theoretical and experimental values of the liquid density, the critical density, the critical temperature, and the binding energy. The stability of the liquid phase is strikingly dependent on band structure. The multivalley structure and mass anisotropy of Si, Ge, and Ge-Si, together with their indirect band gap, are no doubt responsible for the observed stability in these crystals. In the similar semiconductor gallium phosphide, drops have not yet been observed, most likely because the high impurity content traps the excitons. In gallium arsenide the existence of drops is controversial. Undoubtedly drops will be found to exist in other semiconductors, perhaps at even higher temperatures. This is an exciting field for the experimentalist; new phenomena are being rapidly discovered, usually before they are predicted. For the theorist, the electron-hole drop is of high intrinsic interest. It represents the first example of a quantum liquid of constant density in a periodic crystal lattice. A number of challenging experimental and theoretical problems remain.
Rel-Associated pp40: an Inhibitor of the Rel Family of Transcription Factors
Authors: Davis Nathan , Ghosh Sankar , Simmons Daniel L. , Tempst Paul , Liou Hsiou-Chi , Baltimore David , Bose Henry R.
Published: October 2006

The Rel-associated protein pp40 is functionally related to IκB, an inhibitor of the transcription factor NF-κB. Purified pp40 inhibits the DNA binding activity of the NF-κB protein complex (p50:p65 heterodimers), p50:c-Rel heteromers, and c-Rel homodimers. The sequence of the complementary DNA encoding pp40 revealed similarity to the gene encoding MAD-3, a protein with mammalian IκB-like activity. Protein sequencing of IκB purified from rabbit lung confirmed that
MAD-3
encodes a protein similar to IκB. The sequence similarity between MAD-3 and pp40 includes a casein kinase II and consensus tyrosine phosphorylation site, as well as five repeats of a sequence found in the human erythrocyte protein ankyrin. These results suggest that
rel
-related transcription factors, which are capable of cytosolic to nuclear translocation, may be held in the cytosol by interaction with related cytoplasmic anchor molecules.
Cloning of Complementary DNA Encoding a Functional Human Interleukin-8 Receptor
Authors: Murphy Philip M. , Tiffany H. Lee
Published: October 2006

Interleukin-8 (IL-8) is an inflammatory cytokine that activates neutrophil chemotaxis, degranulation, and the respiratory burst. Neutrophils express receptors for IL-8 that are coupled to guanine nucleotide-binding proteins (G proteins); binding of IL-8 to its receptor induces the mobilization of intracellular calcium stores. A cDNA clone from HL-60 neutrophils, designated p2, has now been isolated that encodes a human IL-8 receptor. When p2 is expressed in oocytes from
Xenopus laevis
, the oocytes bind
125
I-labeled IL-8 specifically and respond to IL-8 by mobilizing calcium stores with an EC
50
of 20 nM. This IL-8 receptor has 77% amino acid identity with a second human neutrophil receptor isotype that binds IL-8 with higher affinity. It also exhibits 69% amino acid identity with a protein reported to be an N-formyl peptide receptor from rabbit neutrophils, but less than 30% identity with all other known G protein-coupled receptors, including the human N-formyl peptide receptor.
Molecular Nature of the
Drosophila
Sex Determination Signal and Its Link to Neurogenesis
Authors: Erickson James W. , Cline Thomas W.
Published: October 2006

In 1921 it was discovered that the sexual fate of
Drosophila
is determined by the ratio of X chromosomes to sets of autosomes. Only recently has it been found that the X chromosome to autosome (X:A) ratio is communicated in part by the dose of
sisterless-b
(
sis-b
), an X-linked genetic element located within the
achaete-scute
complex of genes involved in neurogenesis. In this report, the molecular nature of the primary sex determination signal and its relation to these proneural genes was determined by analysis of
sis-b
+
germline transformants. The
sis-b
+
function is conferred by protein T4, a member of the helix-loop-helix family of transcription factors. Although T4 is shared by
sis-b
and
scute
-α, the regulatory regions of
sis-b
, which control T4 expression in sex determination, are both separable from and simpler than those of
scute
-α, which control T4 expression in neurogenesis. Dose-sensitive cooperative interactions in the assembly or binding of
sis
-dependent transcription factors may directly determine the activity of the female-specific promoter of
Sex-lethal
, the master regulator of sexual development. In this model there is no need to invoke the existence of analogous autosomal negative regulators of
Sex-lethal
.
Split Anergy in a CD8
+
T Cell: Receptor-dependent Cytolysis in the Absence of Interleukin-2 Production
Authors: Otten Gillis R. , Germain Ronald N.
Published: October 2006

Engagement of the antigen-specific receptor (TCR) of CD4
+
T lymphocytes without a second (costimulatory) signal prevents the subsequent production of interleukin-2 (IL-2) by these cells. Because IL-2 is a key immunoregulatory lymphokine and is also produced by a subset of CD8
+
T cells that are able to kill target cells, the effect of engaging the TCR of one such clone in the absence of costimulatory signals was examined. The capacity for TCR-dependent IL-2 production was lost, indicating comparable costimulator-dependent signaling requirements for IL-2 production in CD4
+
and CD8
+
T cells. However, TCR-mediated cytotoxicity was not impaired, implying that costimulation is required for only certain TCR-dependent effector functions.
Regulation of Ras-GAP and the Neurofibromatosis-1 Gene Product by Eicosanoids
Authors: Han Jia-Wen , McCormick Frank , Macara Ian G.
Published: October 2006

Ras-GAP (GTPase activating protein) is a regulatory protein that stimulates the intrinsic guanosine triphosphatase (GTPase) activity of the proto-oncogene product p21

ras

. A domain of the neurofibromatosis gene product (NF1) that has sequence similarity to the catalytic domain of Ras-GAP and to yeast IRA gene products also has a specific stimulatory activity toward p21

ras

GTPase. Arachidonic acid and phosphatidic acid inactivate GAP, but no agents have been identified that stimulate GAP and thereby switch p21

ras

off. With the use of recombinant Ha-c-Ras and Ras-GAP, NF1, and GAP catalytic domains, it was found that prostaglandins PGF
2α
and PGA
2
stimulated Ras-GAP and that prostacyclin PGI
2
inhibited Ras-GAP. The stimulatory effect of PGF
2α
was saturable and structure-specific and competed with the inhibitory effect of arachidonic acid. Arachidonic acid also inhibited the catalytic activity of NF1, but prostaglandins were not stimulatory. These results suggest a mechanism for the allosteric control of Ras function through the modulation of arachidonate metabolism.
The Nuclear Debate: Clashes in Congress and California
Authors: Boffey Philip M. , Wade Nicholas
Published: October 2006

Federal and state governments may be headed toward a collision over a key aspect in the development of nuclear power. Antinuclear groups in California are pressing for a law that would ban nuclear power plants unless Congress removes the present legal limitations on the damages payable in the event of a nuclear accident. But Congress, far from repealing the limitation (mandated by the Price-Anderson nuclear insurance law), recently voted to extend it. The skirmish on Capitol Hill over the Price-Anderson law is analyzed in the first of the following articles; the events that have made the California proposition possible are discussed in the second.
Island Biogeography Theory and Conservation Practice
Authors: Simberloff Daniel S. , Abele Lawrence G.
Published: October 2006

The application of island biogeography theory to conservation practice is premature. Theoretically and empirically, a major conclusion of such applications—that refuges should always consist of the largest possible single area—can be incorrect under a variety of biologically feasible conditions. The cost and irreversibility of large-scale conservation programs demand a prudent approach to the application of an insufficiently validated theory.
Design of Specific Inhibitors of Angiotensin-Converting Enzyme: New Class of Orally Active Antihypertensive Agents
Authors: Ondetti Miguel A. , Rubin Bernard , Cushman David W.
Published: October 2006

A hypothetical model of the active site of angiotensin-converting enzyme, based on known chemical and kinetic properties of the enzyme, has enabled us to design a new class of potent and specific inhibitors. These compounds, carboxyalkanoyl and mercaptoalkanoyl derivatives of proline, inhibit the contractile response of guinea pig ileal strip to angiotensin I and augment its response to bradykinin. When administered orally to rats, these agents inhibit the pressor effect of angiotensin I, augment the vasodepressor effect of bradykinin, and lower blood pressure in a model of renovascular hypertension.
Comparative Species Richness in Fluctuating and Constant Environments: Coral-Associated Decapod Crustaceans
Authors: Abele Lawrence G.
Published: October 2006

The number of decapod species associated with the coral
Pocillopora damicornis
is compared between two regions on the Pacific coast of Panama which are of the same geologic age but differ in environmental characteristics. The relationship between number of species and coral head size does not differ between the two regions but species composition among coral heads is more variable in the fluctuating environment. Thus there are more species (55 compared to 37) associated with corals in the fluctuating environment than in the constant environment. These data impugn the concept that environmental constancy increases species richness. They support the hypothesis that species equilibrium within habitats is maintained by measurable ecological factors—in this case, the effects of a natural physical disturbance.
Lekking Behavior in Kafue Lechwe
Authors: Schuster Richard H.
Published: October 2006

The Kafue lechwe (
Kobus leche kafuensis
) exhibits lekking behavior in which a number of males occupy small territories clustered together in discrete areas where females go for mating. Similar behavior in antelope is known only in the Uganda kob (
Kobus kob thomasi
). Lechwe lekking occurs only during a main rutting season although some breeding occurs throughout the year.
Induction of
Plasmodium falciparum
Transmission-blocking Antibodies by Recombinant Vaccinia Virus
Authors: Kaslow David C. , Isaacs Stuart N. , Quakyi Isabella A. , Gwadz Robert W. , Moss Bernard , Keister David B.
Published: October 2006

Many candidate antigens of malaria vaccines have limited immunological recognition. One exception is Pfs25, a cysteine-rich, 25-kilodalton sexual stage surface protein of
Plasmodium falciparum
. Pfs25 is a target of monoclonal antibodies that block transmission of malaria from vertebrate host to mosquito vector. The surface of mammalian cells infected with a recombinant vaccinia virus that expressed Pfs25 specifically bound transmission-blocking monoclonal antibodies. Furthermore, major histocompatibility complex-disparate congenic mouse strains immunized with recombinant Pfs25 elicited transmission-blocking antibodies, demonstrating that the capacity to develop transmission-blocking antibodies is not genetically restricted in mice. Live recombinant viruses may provide an inexpensive, easily administered alternative to subunit vaccines prepared from purified recombinant proteins to block transmission of malaria in developing countries.
Two- Rather Than Three-Dimensional Representation of Saccades in Monkey Superior Colliculus
Authors: van Opstal A. John , Hepp Klaus , Hess Bernhard J. M. , Straumann Dominik , Henn Volker
Published: October 2006

Saccades are controlled by neurons in the brainstem reticular formation that receive input from the superior colliculus and cortex. Recently two quantitative models have been proposed for the role of the colliculus in the generation of three-dimensional eye movements. In order to test these models, three-dimensional eye movements were measured in the alert monkey to investigate whether the saccadic motor map of the superior colliculus is two-dimensional, representing retinal target vectors, or three-dimensional, representing three-dimensional motor error for the rotation of the eye. Electrical stimulation of the superior colliculus produced two-dimensional, not three-dimensional, eye movements. It is therefore concluded that the collicular motor map is two-dimensional.
Targets for Dioxin: Genes for Plasminogen Activator Inhibitor-2 and Interleukin-1β
Authors: Sutter Thomas R. , Guzman Karen , Dold Karen M. , Greenlee William F.
Published: October 2006

Dioxin (2,3,7,8-tetrachlorodibenzo-
p
-dioxin, TCDD), a widespread environmental contaminant, may elicit its effects by altering gene expression in susceptible cells. Five TCDD-responsive complementary DNA clones were isolated from a human keratinocyte cell line. One of these clones encodes plasminogen activator inhibitor-2, a factor that influences growth and differentiation by regulating proteolysis of the extracellular matrix. Another encodes the cytokine interleukin-1β. Thus, TCDD alters the expression of growth regulatory genes and has effects similar to those of other tumor-promoting agents that affect both inflammation and differentiation.
Differential Resource Utilization by the Sexes of Dioecious Plants
Authors: Freeman D. Carl , Klikoff Lionel G. , Harper Kimball T.
Published: October 2006

The distribution of male and female plants was examined in five dioecious, wind-pollinated species representing five plant families and two classes (gymnosperms and angiosperms). The arid to semiarid habitats occupied by these species in northern Utah were stratified for sampling into two categories: chronically xeric and seasonally moist. The results show that for all species, males are more abundant on xeric microsites, while females are overrepresented on the moister parts of each local environment. Differential distribution of the sexes along a soil moisture gradient is a strategy that maximizes seed set of females and pollen dispersal of males; it also tends to minimize intraspecific competition between the sexes.
Physical Properties of the Martian Surface from the Viking 1 Lander: Preliminary Results
Authors: Shorthill Richard W. , Hutton Robert E. , Moore Henry J. , Scott Ronald F. , Spitzer Cary R.
Published: October 2006

The purpose of the physical properties experiment is to determine the characteristics of the martian "soil" based on the use of the Viking lander imaging system, the surface sampler, and engineering sensors. Viking 1 lander made physical contact with the surface of Mars at 11:53:07.1 hours on 20 July 1976 G.M.T. Twenty-five seconds later a high-resolution image sequence of the area around a footpad was started which contained the first information about surface conditions on Mars. The next image is a survey of the martian landscape in front of the lander, including a view of the top support of two of the landing legs. Each leg has a stroke gauge which extends from the top of the leg support an amount equal to the crushing experienced by the shock absorbers during touchdown. Subsequent images provided views of all three stroke gauges which, together with the knowledge of the impact velocity, allow determination of "soil" properties. In the images there is evidence of surface erosion from the engines. Several laboratory tests were carried out prior to the mission with a descent engine to determine what surface alterations might occur during a Mars landing. On sol 2 the shroud, which protected the surface sampler collector head from biological contamination, was ejected onto the surface. Later a cylindrical pin which dropped from the boom housing of the surface sampler during the modified unlatching sequence produced a crater (the second Mars penetrometer experiment). These two experiments provided further insight into the physical properties of the martian surface.
Cyclic GMP Accumulation Causes Degeneration of Photoreceptor Cells: Simulation of an Inherited Disease
Authors: Lolley Richard N. , Farber Debora B. , Rayborn Mary E. , Hollyfield Joe G.
Published: October 2006

Guanosine 3′,5′-monophosphate (cyclic GMP) metabolism in developing eye rudiments of
Xenopus laevis
embryos in culture is disrupted by the phosphodiesterase inhibitor isobutylmethylxanthine. At low concentrations of inhibitor the rudiments develop normally, but at higher concentrations of the inhibitor, cyclic GMP accumulates in the rudiments and the retinal photoreceptor cells degenerate selectively. The isobutylmethylxanthine-induced photoreceptor degeneration is associated with an accumulation of cyclic GMP and, in this respect, it simulates an early biochemical defect in the inherited degenerative disease of
rd
mice.
Threshold Model of Feeding Territoriality and Test with a Hawaiian Honeycreeper
Authors: Carpenter F. L. , MacMillen R. E.
Published: October 2006

A model is proposed predicting that in nectarivorous birds territorial behavior will occur above a lower threshold of nectar productivity in a foraging area and disappear above an upper threshold. These thresholds are determined by the daily costs of living of territorial and of nonterritorial individuals and by the pressure of competing birds for the resource. Decline of efficiency of territorial exclusiveness is predicted as productivity increases from the lower to the upper threshold. Hawaiian honeycreepers (
Vestiaria coccinea
) supported the model.
Submergent Macrophytes: Growth Under Winter Ice Cover
Authors: Boylen Charles W. , Sheldon Richard B.
Published: October 2006

Densities of 26 submergent macrophyte species were determined in situ regularly for 3 years by individuals using self-contained underwater breathing apparatus (scuba). Although most of these species grew only during the summer, ten maintained high population densities and productivity throughout the winter. Maximum winter photosynthetic activity was 10 to 20 percent of summer rates. Extensive productivity of submergent aquatic plants under winter ice cover has not been well documented.
Cellulosic Microfibrils: Nascent Stages of Synthesis in a Higher Plant Cell
Authors: Mueller Susette C. , Brown R. Malcolm , Scott Tom K.
Published: October 2006

Freeze-fracturing of untreated plasma membrane and inner wall surfaces of stelar tissue in corn roots demonstrated the association of globular complexes with the ends of nascent microfibrils. It is proposed that the granule complexes associated with the outer leaflet of the plasma membrane coordinate the assembly of the cellulosic microfibrils.
Black Magnetic Spherule Fallout in the Eastern Gulf of Mexico
Authors: Doyle Larry J. , Hopkins Thomas L. , Betzer Peter R.
Published: October 2006

Large numbers of black metallic spherules ranging in diameter from a few micrometers to over 800 micrometers are raining into the eastern Gulf of Mexico and adjacent areas of western Florida. The composition of the flux, its association with glass spherules and coky particles, and its magnitude point to industrial pollution, probably coal- and coke-burning facilities around the perimeter of the gulf, as the source. Since metallic particles represent only a small fraction of most fly ash, such an influx of large numbers of black magnetic spherules must be symptomatic of a much higher rate of sedimentation of fly ash. The internal microstructures and the general appearance of spherules derived from industrial processes are similar to those of particles derived from cosmic sources. Because of the high potential for contamination in micrometeorite studies, a complete compositional verification of each "cosmic" particle may be necessary.
Protein Hydration in Aqueous Solution
Authors: Otting Gottfried , Liepinsh Edvards , Wüthrich Kurt
Published: October 2006

High-resolution proton nuclear magnetic resonance studies of protein hydration in aqueous solution show that there are two qualitatively different types of hydration sites. A well-defined, small number of water molecules in the interior of the protein are in identical locations in the crystal structure and in solution, and their residence times are in the range from about 10
-2
to 10
-8
second. Hydration of the protein surface in solution is by water molecules with residence times in the subnanosecond range, even when they are located in hydration sites that contain well-ordered water in the x-ray structures of protein single crystals.
Microfabrication Techniques for Integrated Sensors and Microsystems
Authors: Wise K. D. , Najafi K.
Published: October 2006

Integrated sensors and actuators are rapidly evolving to provide an important link between very large scale integrated circuits and nonelectronic monitoring and control applications ranging from biomedicine to automated manufacturing. As they continue to expand, entire microsystems merging electrical, mechanical, thermal, optical, magnetic, and perhaps chemical components should be possible on a common substrate.
Photoreceptor Deactivation and Retinal Degeneration Mediated by a Photoreceptor-Specific Protein Kinase C
Authors: Smith Dean P. , Ranganathan Rama , Hardy Robert W. , Marx Julia , Tsuchida Tammy , Zuker Charles S.
Published: October 2006

The protein kinase C (PKC) family of serine-threonine kinases has been implicated in the regulation of a variety of signaling cascades. One member of this family, eye-PKC, is expressed exclusively in the
Drosophila
visual system. The
inaC
(
inactivation-no-afterpotential C
) locus was shown to be the structural gene for eye-PKC. Analysis of the light response from
inaC
mutants showed that this kinase is required for the deactivation and rapid desensitization of the visual cascade. Light adaptation was also defective in
inaC
mutant flies. In flies carrying the retinal degeneration mutation
rdgB
, absence of eye-PKC suppressed photoreceptor cell degeneration. These results indicate that eye-PKC functions in the light-dependent regulation of the phototransduction cascade in
Drosophila
.
Chemical Basis for Feeding Adaptation of Pine Sawflies
Neodiprion rugifrons
and
Neodiprion swainei
Authors: Ikeda Toshiya , Matsumura Fumio , Benjamin D. M.
Published: October 2006

Larvae of two pine sawflies,
Neodiprion rugifrons
Midd. And
Neodiprion swainei
Midd., consume only old foliage of jack pine,
Pinus banksiana
Lamb., and leave juvenile foliage intact early in the growing season. The chemical basis for this unique adaptation is a feeding deterrent chemical, 13-keto-8(14)-podocarpen-18-oic acid, which was isolated from juvenile foliage. The content of this deterrent chemical decreases as the foliage begins to mature until needles become acceptable to
Neodiprion swainei
larvae by August (60-day-old foliage) and to second-generation
Neodiprion rugifrons
by September (90-day-old foliage). The precise timing of larval acceptance of juvenile foliage indicates a highly specific relationship between these insects and their host tree based on the composition of chemicals in the foliage.
Effects of the Winter of 1976-1977 on the Northwestern Sargasso Sea
Authors: Leetmaa Ants
Published: October 2006

A survey was conducted in the northwestern Sargasso Sea during the spring to assess the effect and extent of the winter cooling of 1976 to 1977 on the ocean. Newly formed, well-mixed layers of 18°C water as deep as 550 meters were observed. The main thermocline south of the Gulf Stream was 100 to 150 meters deeper than it is on the average, which implies significant changes in the baroclinic transports.
Holocene Woodlands in the Southwestern Deserts
Authors: Van Devender Thomas R.
Published: October 2006

Twenty-nine radiocarbon-dated pack rat middens document woodland communities in the deserts of the southwestern United States less than 10,000 years ago. A synchronous change from woodland to desert or grassland occurred about 8000 years ago in the Chihuahuan, Sonoran, and Mohave deserts. A shift of the Aleutian low and the winter storm track to the north, which resulted in drastically reduced winter precipitation in these areas, is inferred. The shift to nonpluvial climates in the Southwest lagged behind the beginning of nonglacial climates in the North because the melting continental glaciers continued to affect general circulation patterns.
Osmotically Induced Changes in Electrical Properties of Plant Protoplast Membranes
Authors: Racusen R. H. , Kinnersley A. M. , Galston A. W.
Published: October 2006

The internal electrical potential of protoplasts from six different plant species was positive. Plasmolyzed cells of leaves had positive voltages of similar magnitude. Both
Elodea
leaf cells and tobacco protoplasts with regenerated cell walls became more electronegative during deplasmolysis. These findings suggest that cell turgor affects membrane components that determine cellular potential.
Sex-Ratio Adjustment in the Common Grackle
Authors: Howe Henry F.
Published: October 2006

From the nestling period through maturity, female grackles are distinctly smaller than males and presumably cost less to rear. Individual birds nesting early in the season lay more female eggs than those nesting later, and in large broods, mortality after hatching consistently favors female fledglings. The first result suggests an adaptive nonrandom meiosis that anticipates seasonal conditions of food availability; the second implies a brood reduction strategy consistent with Fisher's prediction that differential mortality in sexually dimorphic species should favor the less expensive sex.
Participation of the TATA Factor in Transcription of the Yeast U6 Gene by RNA Polymerase C
Authors: Margottin Florence , Dujardin Geneviève , Gérard Matthieu , Egly Jean-Marc , Huet Janine , Sentenac André
Published: October 2006

Fractionation of transcription extracts has led to the identification of multiple transcription factors specific for each form of nuclear RNA polymerase. Accurate transcription in vitro of the yeast U6 RNA gene by RNA polymerase C requires at least two factors. One of them was physically and functionally indistinguishable from transcription factor IID (TFIID or BTF1), a pivotal component of polymerase B transcription complexes, which binds to the TATA element. Purified yeast TFIID (yIID) or bacterial extracts that contained recombinant yIID were equally competent to direct specific transcription of the U6 gene by RNA polymerase C. The results suggest the formation of a hybrid transcription machinery, which may imply an evolutionary relation between class B and class C transcription factors.
T Cell Receptor Peptide Therapy Triggers Autoregulation of Experimental Encephalomyelitis
Authors: Offner Halina , Hashim George A. , Vandenbark Arthur A.
Published: October 2006

Encephalitogenic T cells specific for myelin basic protein share common V
β
8 peptide sequences in their T cell receptor (TCR) that can induce autoregulatory T cells and antibodies that prevent clinical signs of experimental autoimmune encephalomyelitis (EAE). It is not known, however, if TCR peptides can treat established disease. To test its therapeutic value, TCR-V
β
8-39-59 peptide was injected into rats with clinical signs of EAE. This treatment reduced disease severity and speeded recovery, apparently by boosting anti-V
β
8 T cells and antibodies raised naturally in response to encephalitogenic V
β
8
+
T cells. These results demonstrate that synthetic TCR peptides can be used therapeutically, and implicate the TCR-V
β
8-39-59 sequence as a natural idiotope involved in EAE recovery. Similarly, human TCR peptides may be effective in enhancing natural regulation of autoreactive T cells that share common V genes.
Mutagenicity of Filtrates from Respirable Coal Fly Ash
Authors: Chrisp C. E. , Fisher G. L. , Lammert J. E.
Published: October 2006

Incubation of histidine-requiring auxotrophs of the bacterium
Salmonella typhimurium
with cyclohexane-, saline-, and serum-soluble surface components of respirable fly ash particles produced an increased number of revertants in two frameshift tester strains. The results are consistent with the hypothesis that both organic and inorganic mutagens are present in coal fly ash.
Aluminum in Seawater: Control by Biological Activity
Authors: Mackenzie Fred T. , Stoffyn Marc , Wollast Roland
Published: October 2006

The distribution and concentration of dissolved aluminum in a vertical hydrographic profile in the Mediterranean Sea near Corsica are controlled by biological activity. The concentrations of dissolved silica and aluminum covary in the profile and exhibit minima coincident with the seasonal thermocline, a nitrate minimum, and an oxygen maximum. These observations support the hypothesis that the silicon and aluminum cycles in the oceans are linked through the activity of diatoms.
Tree Branch Angle: Maximizing Effective Leaf Area
Authors: Honda Hisao , Fisher Jack B.
Published: October 2006

In a computer simulation of branching pattern and leaf cluster in
Terminalia catappa,
right and left branch angles were varied, and the effective leaf surface areas were calculated. Theoretical branch angles that result in maximum effective leaf area are close to the values observed in nature.
Supersaturated Island Faunas: A Species-Age Relationship for Lizards on Post-Pleistocene Land-Bridge Islands
Authors: Wilcox Bruce A.
Published: October 2006

Lizard faunas on post-Pleistocene land-bridge islands in the region of Baja California were examined for the effect of island age on species diversity. Species diversity and age are significantly correlated; and when the variation in species diversity attributable to area and latitude are removed, the corrected species diversity plotted against island age produces a relaxation or extinction curve. These results provide evidence for supersaturated faunas which are relaxing to lower levels of species diversity consistent with the equilibrium theory of island biogeography.
Salt Domes: Is There More Energy Available from Their Salt than from Their Oil?
Authors: Wick Gerald L. , Isaacs John D.
Published: October 2006

Calculations indicate that a typical oil-bearing salt dome along the Gulf Coast of the United States contains more energy in its salt than is present in its oil. The magnitude of the potential salinity gradient energy is even greater when all of the salt domes are considered.
Senescence of Nickel-Transformed Cells by an X Chromosome: Possible Epigenetic Control
Authors: Klein Catherine B. , Conway Kathleen , Wang Xin Wei , Bhamra Rupinder K. , Lin Xinhua , Cohen Mitchell D. , Annab Lois , Barrett J. Carl , Costa Max
Published: October 2006

Transfer of a normal Chinese hamster X chromosome (carried in a mouse A9 donor cell line) to a nickel-transformed Chinese hamster cell line with an Xq chromosome deletion resulted in senescense of these previously immortal cells. At early passages of the A9/CX donor cells, the hamster X chromosome was highly active, inducing senescence in 100% of the colonies obtained after its transfer into the nickel-transformed cells. However, senescence was reduced to 50% when Chinese hamster X chromosomes were transferred from later passage A9 cells. Full senescing activity of the intact hamster X chromosome was restored by treatment of the donor mouse cells with 5-azacytidine, which induced demethylation of DNA. These results suggest that a senescence gene or genes, which may be located on the Chinese hamster X chromosome, can be regulated by DNA methylation, and that escape from senescence and possibly loss of tumor suppressor gene activity can occur by epigenetic mechanisms.
Fusion Energy in Context: Its Fitness for the Long Term
Authors: Holdren John P.
Published: October 2006

Long-term limits to growth in energy will be imposed not by inability to expand supply, but by the rising environmental and social costs of doing so. These costs will therefore be central issues in choosing long-term options. Fusion, like solar energy, is not one possibility but many, some with very attractive environmental characteristics and others perhaps little better in these regards than fission. None of the fusion options will be cheap, and none is likely to be widely available before the year 2010. The most attractive forms of fusion may require greater investments of time and money to achieve, but they are the real reason for wanting fusion at all.