bluuebunny/crossref_metadata_2025 huggingface dataset:
Progression to Diabetes in Nonobese Diabetic (NOD) Mice with Transgenic T Cell Receptors
Authors: Lipes Myra A. , Rosenzweig Anthony , Tan Kut-Nie , Tanigawa Gary , Ladd Dan , Seidman Jonathan G. , Eisenbarth George S.
Published: October 2006

The T cell receptor (TCR) requirements in the pathogenesis of insulin-dependent diabetes were examined with transgenic NOD mice bearing nondisease-related TCR α and β chains. In both TCRβ and TCRαβ transgenic NOD mice the β chain transgene was expressed by > 98% of peripheral T cells. The α chain transgene was also highly expressed. Insulitis developed in both sets of transgenic animals with most of the lymphocytes in the lesion expressing the transgenic β chain and with depletion of the endogenous TCR V
β
genes. Nonetheless, NOD animals transgenic for TCRβ and TCRαβ developed diabetes similar to controls. Thus, skewing the TCR repertoire did not diminish autoimmune susceptibility in NOD mice.
Octopine as an End Product of Anaerobic Glycolysis in the Chambered Nautilus
Authors: Hockachka P. W. , Hartline P. H. , Fields J. H. A.
Published: October 2006

The terminal step in the anaerobic glycolysis of muscle in the chambered nautilus,
Nautilus pompilius
, is not pyruvate reduction to lactate as in vertebrate muscle. Instead of lactate dehydrogenase, these organisms utilize octopine dehydrogenase (E.C. 1.5.1.11), catalyzing the reductive condensation of pyruvate and arginine, which is dependent on the reduced form of nicotinamide adenine dinucleotide, to form octopine and the oxidized form of the coenzyme. The kinetic properties of octopine dehydrogenase favor the production of octopine, which accumulates under a variety of conditions.
Arabidopsis thaliana
DNA Methylation Mutants
Authors: Vongs Aurawan , Kakutani Tetsuji , Martienssen Robert A. , Richards Eric J.
Published: October 2006

Three DNA hypomethylation mutants of the flowering plant
Arabidopsis thaliana
were isolated by screening mutagenized populations for plants containing centromeric repetitive DNA arrays susceptible to digestion by a restriction endonuclease that was sensitive to methylated cytosines. The mutations are recessive, and at least two are alleles of a single locus, designated
DDM1
(for decrease in DNA methylation). Amounts of 5-methylcytosine were reduced over 70 percent in
ddm1
mutants. Despite this reduction in DNA methylation levels,
ddm1
mutants developed normally and exhibited no striking morphological phenotypes. However, the
ddm1
mutations are associated with a segregation distortion phenotype. The
ddm1
mutations were used to demonstrate that de novo DNA methylation in vivo is slow.
The Function of GRB2 in Linking the Insulin Receptor to Ras Signaling Pathways
Authors: Skolnik E. Y. , Batzer A. , Li N. , Lee C.-H. , Lowenstein E. , Mohammadi M. , Margolis B. , Schlessinger J.
Published: October 2006

Insulin-induced activation of extracellular signal-regulated kinases [ERKs, also known as mitogen-activated protein (MAP) kinases] is mediated by Ras. Insulin activates Ras primarily by increasing the rate of guanine nucleotide-releasing activity. Here, we show that insulin-induced activation of ERKs was enhanced by stable overexpression of growth factor receptor-bound protein 2 (GRB2) but not by overexpression of GRB2 proteins with point mutations in the Src homology 2 and 3 domains. Moreover, a dominant negative form of Ras (with Ser
17
substituted with Asn) blocked insulin-induced activation of ERKs in cells that overexpressed GRB2. GRB2 overexpression led to increased formation of a complex between the guanine nucleotide-releasing factor Sos (the product of the mammalian homolog of
son of sevenless
gene) and GRB2. In response to insulin stimulation, this complex bound to tyrosine-phosphorylated IRS-1 (insulin receptor substrate-1) and Shc. In contrast to the activated epidermal growth factor receptor that binds the GRB2-Sos complex directly, activation of the insulin receptor results in the interaction of GRB2-Sos with IRS-1 and Shc, thus linking the insulin receptor to Ras signaling pathways.
Transcription Factor TFIIB Sites Important for Interaction with Promoter-Bound TFIID
Authors: Yamashita Shinya , Hisatake Koji , Kokubo Tetsuro , Doi Katsumi , Roeder Robert G. , Horikoshi Masami , Nakatani Yoshihiro
Published: October 2006

Transcription initiation factor TFIIB recruits RNA polymerase II to the promoter subsequent to interaction with a preformed TFIID-promoter complex. The domains of TFIIB required for binding to the TFIID-promoter complex and for transcription initiation have been determined. The carboxyl-terminal two-thirds of TFIIB, which contains two direct repeats and two basic residue repeats, is sufficient for interaction with the TFIID-promoter complex. An extra 84-residue amino-terminal region, with no obvious known structural motifs, is required for basal transcription activity. Basic residues within the second basic repeat of TFIIB are necessary for stable interaction with the TFIID-promoter complex, whereas the basic character of the first basic repeat is not. Functional roles of other potential structural motifs are discussed in light of the present study.
Hyperosmolality in Intraluminal Fluids from Hamster Testis and Epididymis: A Micropuncture Study
Authors: Johnson Anne L. , Howards Stuart S.
Published: October 2006

Intraluminal fluids from the hamster seminiferous tubules, rete testis, and caput, corpus, and cauda epididymidis were obtained in vivo by micropuncture. Rete testis fluid is isosmolar with serum. Fluids from the seminiferous tubules and all sites in the epididymis are hyperosmolar.
Does "Blastocyst Estrogen" Initiate Implantation?
Authors: Dickmann Zeev , Gupta Jayasree Sen , Dey Sudhansu K.
Published: October 2006

Fertilized eggs were incubated for 2 hours in a medium containing estradiol-17β and then transferred into the uteri of day 5 pseudopregnant rats. These eggs, but not estrogen-free control eggs, induced a local increase in capillary permeability. We suggest that the blastocyst factor which induces the local increase in capillary permeability during early pregnancy is estrogen synthesized by the blastocyst.
Pathogenic Mycoplasmas: Cultivation and Vertebrate Pathogenicity of a New Spiroplasma
Authors: Tully Joseph G. , Whitcomb Robert F. , Clark H Fred , Williamson David L.
Published: October 2006

A spiroplasma recovered from allantoic fluids of chick embryos infected with the tick-derived suckling mouse cataract agent was grown in continuous passage on a new artificial culture medium. The cultured organisms induced typical ocular and other disease symptoms in susceptible animals, and were reisolated from involved host tissues. Although spiroplasmas have been previously recognized as plant and insect pathogens, this is the first spiroplasma shown to multiply at 37°C and to be pathogenic for vertebrates.
Requirement for CD8
+
Cells in T Cell Receptor Peptide-Induced Clonal Unresponsiveness
Authors: Gaur Amitabh , Ruberti Giovina , Haspel Richard , Mayer John P. , Fathman C. Garrison
Published: October 2006

T cell receptor (TCR) vaccination in rats prevents the development of experimental allergic encephalomyelitis (EAE), an animal model of multiple sclerosis. The mechanism of this potential immunotherapy was examined by vaccinating mice with an immunogenic peptide fragment of the variable region of the TCR V
β
8.2 gene. Another immunogen that usually induces an immune response mediated by V
β
8.2
+
T cells was subsequently inhibited because specific clonal unresponsiveness (anergy) had been induced. Depletion of CD8
+
cells before TCR peptide vaccination blocked such inhibition. Thus, the clonal anergy was dependent on CD8
+
T cells, and such immunoregulatory T cells may participate in the normal course of EAE.
Toward a Model for the Interaction Between Elongation Factor Tu and the Ribosome
Authors: Weijland Albert , Parmeggiani Andrea
Published: October 2006

In the elongation cycle of bacterial protein synthesis the interaction between elongation factor-Tu (EF-Tu)⋅guanosine triphosphate (GTP), aminoacyl-transfer RNA (aa-tRNA), and messenger RNA-programmed ribosomes is associated with the hydrolysis of GTP. This interaction determines the selection of the proper aa-tRNA for incorporation into the polypeptide. In the canonical scheme, one molecule of GTP is hydrolyzed in the EF-Tu-dependent binding of aa-tRNA to the ribosome, and a second molecule is hydrolyzed in the elongation factor-G (EF-G)-mediated translocation of the polypeptide from the ribosomal A site to the P site. Substitution of Asp
138
with Asn in EF-Tu changed the substrate specificity from GTP to xanthosine triphosphate and demonstrated that the EF-Tu-mediated reactions involved the hydrolysis of two nucleotide triphosphates for each Phe incorporated. This stoichiometry of two is associated with the binding of the correct aa-tRNA to the ribosome.
Structure-Based Discovery of Inhibitors of Thymidylate Synthase
Authors: Shoichet Brian K. , Stroud Robert M. , Santi Daniel V. , Kuntz Irwin D. , Perry Kathy M.
Published: October 2006

A molecular docking computer program (DOCK) was used to screen the Fine Chemical Directory, a database of commercially available compounds, for molecules that are complementary to thymidylate synthase (TS), a chemotherapeutic target. Besides retrieving the substrate and several known inhibitors, DOCK proposed putative inhibitors previously unknown to bind to the enzyme. Three of these compounds inhibited
Lactobacillus casei
TS at submillimolar concentrations. One of these inhibitors, sulisobenzone, crystallized with TS in two configurations that differed from the DOCK-favored geometry: a counterion was bound in the substrate site, which resulted in a 6 to 9 angstrom displacement of the inhibitor. The structure of the complexes suggested another binding region in the active site that could be exploited. This region was probed with molecules sterically similar to sulisobenzone, which led to the identification of a family of phenolphthalein analogs that inhibit TS in the 1 to 30 micromolar range. These inhibitors do not resemble the substrates of the enzyme. A crystal structure of phenolphthalein with TS shows that it binds in the target site in a configuration that resembles the one suggested by DOCK.
Requirement for Cdk2 in Cytostatic Factor-Mediated Metaphase II Arrest
Authors: Gabrielli Brian G. , Roy Linda M. , Maller James L.
Published: October 2006

The unfertilized eggs of vertebrates are arrested in metaphase of meiosis II because of the activity of cytostatic factor (CSF).
Xenopus
CSF is thought to contain the product of the
Mos
proto-oncogene, but other proteins synthesized during meiosis II are also required for arrest induced by CSF. In
Xenopus
oocytes, ablation of synthesis of cyclin-dependent kinase 2 (Cdk2) during meiosis resulted in absence of the metaphase II block, even though the Mos
xe
protein kinase was fully active at metaphase. Introduction of purified Cdk2 restored metaphase II arrest, and increasing the amount of Cdk2 during meiosis I (when Mos
xe
is present) led to metaphase arrest at meiosis I. These data indicate that metaphase arrest is a result of cooperation between a proto-oncogene kinase and a cyclin-dependent kinase and illustrate the interaction of a cell growth regulator with a cell cycle control element.
Activity-Dependent Regulation of Conductances in Model Neurons
Authors: LeMasson Gwendal , Marder Eve , Abbott L. F.
Published: October 2006

Neurons maintain their electrical activity patterns despite channel turnover, cell growth, and variable extracellular conditions. A model is presented in which maximal conductances of ionic currents depend on the intracellular concentration of calcium ions and so, indirectly, on activity. Model neurons with activity-dependent maximal conductances modify their conductances to maintain a given behavior when perturbed. Moreover, neurons that are described by identical sets of equations can develop different properties in response to different patterns of presynaptic activity.
An Essential Heparin-Binding Domain in the Fibroblast Growth Factor Receptor Kinase
Authors: Kan Mikio , Wang Fen , Xu Jianming , Crabb John W. , Hou Jinzhao , McKeehan Wallace L.
Published: October 2006

Heparin or heparin-like heparan sulfate proteoglycans are obligatory for activity of the heparin-binding fibroblast growth factor (FGF) family. Heparin interacts independently of FGF ligand with a specific sequence (K18K) in one of the immunoglobulin-like loops in the extracellular domain of the FGF receptor tyrosine kinase transmembrane glycoprotein. A synthetic peptide corresponding to K18K inhibited heparin and heparin-dependent FGF binding to the receptor. K18K and an antibody to K18K were antagonists of FGF-stimulated cell growth. Point mutations of lysine residues in the K18K sequence abrogated both heparin- and ligand-binding activities of the receptor kinase. The results indicate that the FGF receptor is a ternary complex of heparan sulfate proteoglycan, tyrosine kinase transmembrane glycoprotein, and ligand.
Aqueous-Phase Photochemical Formation of Peroxides in Authentic Cloud and Fog Waters
Authors: Faust Bruce C. , Anastasio Cort , Allen John M. , Arakaki Takemitsu
Published: October 2006

Gas-to-drop partitioning of hydrogen peroxide and its precursor, the hydroperoxyl radical (HO
⋅
2
), has been considered the predominant or sole source of hydrogen peroxide in atmospheric water drops. However, atmospheric water can absorb solar ultraviolet radiation, which initiates the photoformation of peroxides (primarily hydrogen peroxide). Measurements of peroxide photoformation rates in authentic atmospheric water samples demonstrate that aqueous-phase photochemical reactions are a significant, and in some cases dominant, source of hydrogen peroxide to cloud and fog drops. This additional source could significantly change the current understanding, and hence, the models, of sulfuric acid deposition because hydrogen peroxide is the limiting reagent in the dominant pathway for the oxidation of sulfur dioxide to sulfuric acid in the troposphere over eastern North America.
Imaging of Features on Surfaces by Condensation Figures
Authors: López Gabriel P. , Biebuyck Hans A. , Frisbie C. Daniel , Whitesides George M.
Published: October 2006

Condensation of a vapor to a liquid on a cold surface that is not wet completely by this liquid leads to the formation of an array of droplets. If the surface is heterogeneous in its physical properties (especially its interfacial free energy), the patterns of these arrays reflect this heterogeneity. The distribution of droplets of water (condensation figures or CFs) observed by optical microscopy on a surface can be correlated with the molecular structure of that surface. The substrates used to investigate the formation and morphology of the CFs were patterned, self-assembled monolayers of different alkanethiolates on gold and of alkyl siloxanes on glass. Analysis of CFs is a valuable nondestructive technique for characterizing heterogeneities in surfaces.
Cue-Invariant Shape Selectivity of Macaque Inferior Temporal Neurons
Authors: Sáry Gyula , Vogels Rufin , Orban Guy A.
Published: October 2006

The perception of shape is independent of the size and position of the shape and also of the visual cue that defines it. The same shape can be recognized whether defined by a difference in luminance, by motion, or by texture. Experiments showed that the shape selectivity of individual cells in the macaque inferior temporal cortex did not vary with the size and position of a shape and also did not vary with the visual cue used to define the shape. This cue invariance was true for static luminance and texture cues as well as for relative motion cues—that is, for cues that are processed in ventral and dorsal visual pathways. The properties of these inferior temporal cells meet the demands of cue-invariant shape coding.
Substrate Phage: Selection of Protease Substrates by Monovalent Phage Display
Authors: Matthews David J. , Wells James A.
Published: October 2006

A method is described here for identifying good protease substrates among approximately 10
7
possible sequences. A library of fusion proteins was constructed containing an amino-terminal domain used to bind to an affinity support, followed by a randomized protease substrate sequence and the carboxyl-terminal domain of M13 gene III. Each fusion protein was displayed as a single copy on filamentous phagemid particles (substrate phage). Phage were then bound to an affinity support and treated with the protease of interest. Phage with good protease substrates were released, whereas phage with substrates that resisted proteolysis remained bound. After several rounds of binding, proteolysis, and phagemid propagation, sensitive and resistant substrate sequences were identified for two different proteases, a variant of subtilisin and factor X
a
. The technique may also be useful for studying the sequence specificity of a variety of posttranslational modifications.
Human Sos1: a Guanine Nucleotide Exchange Factor for Ras that Binds to GRB2
Authors: Chardin Pierre , Camonis Jacques H. , Gale Nicholas W. , van Aelst Linda , Schlessinger Joseph , Wigler Michael H. , Bar-Sagi Dafna
Published: October 2006

A human complementary DNA was isolated that encodes a widely expressed protein, hSos1, that is closely related to Sos, the product of the
Drosophila
son of sevenless gene. The hSos1 protein contains a region of significant sequence similarity to CDC25, a guanine nucleotide exchange factor for Ras from yeast. A fragment of hSos1 encoding the CDC25-related domain complemented loss of CDC25 function in yeast. This hSos1 domain specifically stimulated guanine nucleotide exchange on mammalian Ras proteins in vitro. Mammalian cells overexpressing full-length hSos1 had increased guanine nucleotide exchange activity. Thus hSos1 is a guanine nucleotide exchange factor for Ras. The hSos1 interacted with growth factor receptor-bound protein 2 (GRB2) in vivo and in vitro. This interaction was mediated by the carboxyl-terminal domain of hSos1 and the Src homology 3 (SH3) domains of GRB2. These results suggest that the coupling of receptor tyrosine kinases to Ras signaling is mediated by a molecular complex consisting of GRB2 and hSos1.
The Isolation of Tobacco Ring Spot and Other Virus Proteins by Ultracentrifugation
Authors: Stanley W. M. , Wyckoff Ralph W. G.
Published: October 2006

A high molecular weight crystalline protein, possessing the properties of ring spot virus and differing markedly from tobacco mosaic virus protein in its physical, chemical and serological properties, has been isolated by means of an ultracentrifuge from Turkish tobacco plants diseased with tobacco ring spot virus. Ultracentrifugal methods were also used to demonstrate that high molecular weight proteins are characteristic of other virus diseases. The concentration of the different virus proteins in the host was found to differ greatly. The quantity ultracentrifuge, used in conjunction with an analytical ultracentrifuge, has proven to be a powerful tool for the concentration, purification and crystallization of high molecular weight virus proteins and to be indispensable in the case of unstable viruses existing in low concentration in the host.
The Elusive Rise in the American Birthrate
Authors: Gibson Campbell
Published: October 2006

In summary, (i) neither an immediate nor a dramatic increase in fertility will be required during the next few years for young married women to realize their family-size expectations; (ii) annual fertility trends in California do not provide a useful indicator of annual fertility trends at the national level; (iii) recent economic trends appear to merit considerable attention in an assessment of future fertility prospects. An examination of recent economic conditions suggests that a substantial increase in annual fertility is unlikely to occur immediately. It would be more likely to occur when the current unfavorable economic conditions have been eliminated.
Changes in Human Tissue Electrolytes in Senescence
Authors: Simms Henry S. , Stolman Abraham
Published: October 2006

Analyses of tissues from people over seventy years old who died from accidents were compared with analyses of tissues from thirty to forty-year-old people who also died from accidents. The old tissues contained more water, chloride, total base, sodium and calcium; and they contained less potassium, magnesium, phosphorus, nitrogen and ash than the younger tissue.
Radioimmunoassay for Abnormal Hemoglobins
Authors: Garver Fred A. , Baker Marilyn B. , Jones C. Sidney , Gravely Marsha , Altay Gultekin , Huisman Titus H. J.
Published: October 2006

A sensitive and specific radioimmunoassay has been developed for the identification or quantification of the human hemoglobin variants S, C, D-Los Angeles, E, G Philadelphia, Russ, O Arab, Beograd, J Paris I, G San Jose, Q Iran, Korle Bu, and F Malta I. In the immunoassay, monospecific antibody preparations are used which recognize the single amino acid substitution in the variant polypeptide chain and do not cross-react with normal hemoglobins or hemoglobin variants containing a different amino acid exchange at the same position.
Monomeric Forms of the Acid Ionophore Lasalocid A (X-537A) from Polar Solvents
Authors: Chiang Chian C. , Paul Iain C.
Published: October 2006

X-ray structural analyses have been carried out on the free acid of lasalocid A (X-537A) and on the sodium salt, both crystallized from methanol solution. In each case the structure is monomeric with one molecule of methanol complexing to the free acid and to the salt.
Somatostatin: Electron Microscope Immunohistochemical Localization in Secretory Neurons of Rat Hypothalamus
Authors: Pelletier Georges , Dubé Donald , Puviani Romano
Published: October 2006

Somatostatin, the hypothalamic hormone which inhibits the secretion of growth hormone by the pituitary, has been localized in the rat hypothalamus by using electron microscope immunohistochemistry. Somatostatin occurs in secretory granules (80 to 110 nm in diameter) of a few neurons located in the hypothalamic periventricular nucleus. These observations establish the identity of neurosecretory neurons involved in the regulation of adenohypophyseal secretion.
Isolation and Characterization of an Endogenous Type C Virus of Rhesus Monkeys
Authors: Rabin Harvey , Benton Charles V. , Tainsky Michael A. , Rice Nancy R. , Gilden Raymond V.
Published: October 2006

A type C retrovirus was isolated from a continuous cell line established from a spontaneous esophageal carcinoma of a rhesus monkey (
Macaca mulata
) by prolonged cocultivation with canine cells. A DNA transcript of the viral RNA hybridized to a high level and kinetic analysis indicated the presence of multiple copies of the viral genome in rhesus monkey DNA, showing that the virus is endogenous in this species. The rhesus monkey virus closely resembles, in several respects, an endogenous type C virus previously isolated from stumptailed macaques (
Macaca arctoides
), a species closely related to rhesus monkeys.
Antibody-Induced Antigen Redistribution and Shedding from Human Breast Cancer Cells
Authors: Nordquist Robert E. , Anglin J. Hill , Lerner Michael P.
Published: October 2006

Cell surface antigens of human breast cancer cells undergo a rapid redistribution when bound by antibodies from cancer patients. The subsequent shedding of these antigen-antibody complexes and free antigen may be instrumental in tumor survival.
Phase Control of Neural Pacemakers
Authors: Winfree A. T.
Published: October 2006

An electrical stimulus resets the phase of a spontaneously rhythmic neuron. The "new phase" versus "old phase" curve shows either of two distinct topological characters, depending on the stimulus magnitude. These features, and a phase singularity implicit in them, are common to many stable oscillations deriving from continuous feedback between two or more biophysical quantities.
The Loss of Resistance to Murine Typhus Infection Resulting from Riboflavin Deficiency in Rats
Authors: Pinkerton Henry , Bessey Otto A.
Published: October 2006

Riboflavin deficiency, even in a relatively early stage, greatly lowers the resistance of the rat to endemic typhus, thereby resulting in a fatal disease. Not only the serosal cells, but also the endothelial cells in several organs, notably the Kupfer cells of the liver, become greatly distended with rickettsiae under these conditions. Preliminary experiments strongly suggest that advanced vitamin A deficiency, even when making animals markedly cachetic, does not have a comparable effect. Riboflavin deficient animals remain alive for several weeks with an abnormal intracellular metabolism. This type of deficiency is worthy of further study as a possible method of approach in the investigation of other intracellular parasites and filtrable viruses. Speculation regarding the mechanism concerned also suggests the desirability of a study of the effects of this deficiency upon the production of immune bodies in general.
Cortical Mechanisms that Augment or Reduce Evoked Potentials in Cats
Authors: Lukas Jeffrey H. , Siegel Jerome
Published: October 2006

The augmenting or reducing of flash-evoked potentials in paralyzed cats was significantly correlated with their previously videotaped behaviors. Augmenting reducing was due to alterations in cortical rather than subcortical responsiveness, and was duplicated by increasing cortical arousal by means of reticular stimulation while the animal was exposed to visual stimuli of constant intensity. Brainstem activation of cortical inhibition may underlie the behavioral results as well as the results obtained with the evoked potentials.
Amacrine Cells in
Necturus
Retina: Evidence for Independent γ-Aminobutyric Acid- and Glycine-Releasing Neurons
Authors: Miller Robert F. , Dacheux Ramon F. , Frumkes Thomas E.
Published: October 2006

About one-half of on-off ganglion cells have inhibitory postsynaptic potentials (IPSP's) which are blocked by strychnine, while the remainder have IPSP's which are blocked by picrotoxin or bicuculline. These antagonists do not abolish light activity of the presynaptic inhibitory neuron, the amacrine cell. The existence of separate γ-aminobutyric acid- and glycine-releasing amacrine cells is implied by these results.
A New Estrogenic Substance Present in the Neutral Fraction of Human Pregnancy Urine
Authors: Dorfman Ralph I.
Published: October 2006

In addition to the well-defined phenolic estrogens in human pregnancy urine there appears to be another estrogenic substance which is a neutral non-ketonic compound.
Body Weight: Reduction by Long-Term Glycerol Treatment
Authors: Wirtshafter David , Davis John D.
Published: October 2006

Elevation of body glycerol concentration by multiple daily injections of glycerol was shown to lead to hypophagia and body weight loss followed by normal food intake and normal rate of body weight increase in rats. Termination of injections was followed by hyperphagia and an accelerated rate of growth. These findings suggest that the blood glycerol concentration plays an important role in the control of body weight and may be one signal by which the central nervous system monitors body lipid content.
Northern Fur Seal Diving Behavior: a New Approach to Its Study
Authors: Kooyman G. L. , Gentry R. L. , Urguhart D. L.
Published: October 2006

A new type of depth-time recorder was used to monitor behavior of fur seals at sea. During 608 hours, 2957 dives were recorded for four animals. The deepest dive was 190 meters, and the longest submersion was 5.6 minutes.
Susceptibility of Mice to Audiogenic Seizures Is Increased by Handling Their Dams During Gestation
Authors: Beck Sidney L. , Gavin Donna L.
Published: October 2006

Fetal mice treated on days 10, 11, and 12 of gestation by injecting the mothers with (i) 50 milligrams of β-2-thienylalanine, (ii) solvent, or (iii) sham injection had identical frequencies of audiogenic seizures when tested 23 days after birth; these frequencies were significantly higher than those of an unhandled control group. Results of the sham treatment suggest that maternal stress induced by handling, rather than the nature of the substance injected, increased the susceptibility of the offspring to seizures.
Pattern Regulation in Epimorphic Fields
Authors: French Vernon , Bryant Peter J. , Bryant Susan V.
Published: October 2006

We have described a formal model for pattern regulation in epimorphic fields in which positional information is specified in terms of polar coordinates in two dimensions. We propose that cells within epimorphic fields behave according to two simple rules, the shortest intercalation rule and the complete circle rule, for both of which there is direct experimental evidence. It is possible to understand a large number of different behaviors of epimorphic fields as a straight-forward consequence of these two rules, and the model therefore provides a context in which to view many of the results of experimental embryology. Although we have confined our discussion to cockroach legs, the imaginal disks of Drosophila, and regenerating and developing amphibian limbs, the fact that the model can explain regulative behavior in such evolutionarily diverse animals suggests that it may have general applicability to epimorphic fields. The predictions which the model makes should make it possible to assess its applicability to other developing systems, and to investigate the cellular mechanisms involved.
Cytoplasmic Aldo-Keto Reductases: A Class of Drug Metabolizing Enzymes
Authors: Bachur Nicholas R.
Published: October 2006

Aldehyde and ketone xenobiotic substances are preferentially reduced to alcohols by cytoplasmic enzymes in mammals. These enzymes are widely distributed in the tissues, have broad substrate specificities, have similar physical-chemical characteristics, and require reduced nicotinamide adenine dinucleotide as cofactor for the reductions. These reductases define a system of detoxification for aldehyde and ketone groups.
Flow-Field-Flow Fractionation: A Versatile New Separation Method
Authors: Giddings J. Calvin , Yang Frank J. F. , Myers Marcus N.
Published: October 2006

Flow field-flow fractionation is a new separation technique that seems likely to have broad applicability. Its theoretical scope includes any solute for which one can find a solvent and a semipermeable membrane. The principles on which the technique is based are presented. Some experiments with polystyrene beads, viruses, and proteins verify that retention depends solely on diffusion coefficients.
Responses of Infants to Visually Presented Objects
Authors: Dodwell P. C. , Muir D. , DiFranco D.
Published: October 2006

The reaching behavior of some 60 infants between 7 and 23 days of age was studied. Contrary to some other reports, the infants did not respond differently to a visually presented, graspable, solid object than to its two-dimensional representation.
Discovery of Insect Anti-Juvenile Hormones in Plants
Authors: Bowers William S. , Ohta Tomihisa , Cleere Tomihisa , Marsella Patricia A.
Published: October 2006

Two simple chromenes with anti-JH activity have been isolated and identified from the bedding plant
Ageratum houstonianum
. By contact and fumigation these compounds induce precocious metamorphosis and sterilization in several hemipteran species of insects. Certain holometabolous species are sterilized, forced into diapause, or both. Each of these biological actions is equivalent to removal of the corpora allata, which produce the JH's, and is reversible by treatment with exogenous JH. Thus, the action of these compounds is to stop the production or depress the titer of the JH's. To our knowledge, this is the first discovery of anti-JH, and we hope it will guide the way to the emergence of a fourth generation of safe and insect-specific pesticides.
Low-Risk Cigarettes: A Prescription
Authors: Gori GB
Published: October 2006

Antismoking education campaigns in our society have met with only partial success: today 55 to 60 million Americans smoke, and the habit is increasing among teenagers and women. It is important to protect individuals who continue to smoke despite all warnings. There is evidence that this can be accomplished in at least two ways.

First, it may be possible to remove toxic smoke components and thus reduce specific hazards. Second, the dose-response evidence suggests that, if the total intake of smoke can be reduced, after an appropriate time a reduction in disease incidence should occur. The technology to achieve these results has been developed and can be applied to the manufacture of commercial cigarettes. These cigarettes will not conform to traditional flavor patterns, but consumer perception can be made to change and compensating flavors and fragrances can be added.

The feasibility of less hazardous cigarettes raises the question of whether there are limits of cigarette and smoke composition that may approach relative safety. These limits can be defined as the smoke intake doses at which the risk of disease in smokers approaches that in nonsmokers. Such values can be estimated by dose-response analysis of several epidemiological studies and by extrapolation of blood concentrations at different rates of intake for certain smoke components, such as carbon monoxide. Critical values determined by these methods should not be interpreted as indicators of safe smoking levels; they do imply, however, that a rapid shift in cigarette consumption habits toward the proposed range of values will make possible a substantial reduction in the current epidemic proportions of smoking-related diseases.
MEAN-FIELD EXPANSION IN BOSE–EINSTEIN CONDENSATES WITH FINITE-RANGE INTERACTIONS
Authors: SCHÜTZHOLD RALF , UHLMANN MICHAEL , XU YAN , FISCHER UWE R.
Published: October 2006

We present a formal derivation of the mean-field expansion for dilute Bose–Einstein condensates with two-particle interaction potentials which are weak and finite-range, but otherwise arbitrary. The expansion allows for a controlled investigation of the impact of microscopic interaction details (e.g. the scaling behavior) on the mean-field approach and the induced higher-order corrections beyond the s-wave scattering approximation.
Odd-skipped genes specify the signaling center that triggers retinogenesis inDrosophila
Authors: Bras-Pereira Catarina , Bessa Jose , Casares Fernando
Published: October 2006

Although many of the factors responsible for conferring identity to the eye field in Drosophila have been identified, much less is known about how the expression of the retinal `trigger', the signaling molecule Hedgehog,is controlled. Here, we show that the co-expression of the conserved odd-skipped family genes at the posterior margin of the eye field is required to activate hedgehog expression and thereby the onset of retinogenesis. The fly Wnt1 homologue wingless represses the odd-skipped genes drm and odd along the anterior margin and,in this manner, spatially restricts the extent of retinal differentiation within the eye field.
Joint work and power for both the forelimb and hindlimb during trotting in the horse
Authors: Dutto Darren J. , Hoyt Donald F. , Clayton Hilary M. , Cogger Edward A. , Wickler Steven J.
Published: October 2006

The net work of the limbs during constant speed over level ground should be zero. However, the partitioning of negative and positive work between the fore- and hindlimbs of a quadruped is not likely to be equal because the forelimb produces a net braking force while the hindlimb produces a net propulsive force. It was hypothesized that the forelimb would do net negative work while the hindlimb did net positive work during trotting in the horse. Because vertical and horizontal impulses remain unchanged across speeds it was hypothesized that net work of both limbs would be independent of speed. Additionally because the major mass of limb musculature is located proximally,it was hypothesized that proximal joints would do more work than distal joints. Kinetic and kinematic analysis were combined using inverse dynamics to calculate work and power for each joint of horses trotting at between 2.5 and 5.0 m s–1.

Work done by the hindlimb was indeed positive (consistently 0.34 J kg–1 across all speeds), but, contrary to our hypothesis, net work by the forelimb was essentially zero (but also independent of trotting speed). The zero net work of the forelimb may be the consequence of our not being able to account, experimentally, for the negative work done by the extrinsic muscles connecting the scapula and the thorax. The distal three joints of both limbs behaved elastically with a period of energy absorption followed by energy return. Proximal forelimb joints (elbow and shoulder) did no net work, because there was very little movement of the elbow and shoulder during the portion of stance when an extensor moment was greatest. Of the two proximal hindlimb joints, the hip did positive work during the stride,generating energy almost throughout stance. The knee did some work, but like the forelimb proximal joints, had little movement during the middle of stance when the flexion moment was the greatest, probably serving to allow the efficient transmission of energy from the hip musculature to the ground.
Negative pressure in the middle ear by ciliary propulsion of mucus through the eustachian tube
Authors: Murphy David
Published: October 2006

Mucus was placed in the middle ears of 11 cats. A needle and stop‐cock placed in the bulla communicated with the tympanic cavity. The pressure changes in the needle were transcribed on a flowing graph via a transducer in communication with the stop‐cock. Negative pressure developed in each test ear. The average maximum negative pressure was 12 mm Hg with a minimum of 2 mm Hg and maximum of 24 mm Hg. The peak negative pressure, reached in 30 to 60 min. in most ears, occurred in 10 min. in one and in 3 hrs. in another. The qualitative results show all ears developed a negative pressure when mucus was in the tympanic cavity. The quantitative data suggest an average maximum negative pressure of 12 mm Hg reached at about 1 hr.
The changing characteristics of acoustic neuroma patients over the last 10 years
Authors: Glasscock Michael E. , Levine Samuel C. , Mckennan Kevin X.
Published: October 2006

The first 100 patients in a series of 616 cerebellopontine angle tumors were compared to the most recent 100 patients. All of the first 100 patients were evaluated prior to the common use of CT or ABR. Recently, improved diagnostic studies have resulted in the discovery of significantly smaller tumors. The later group of patients was also found to have their symptoms for a shorter period of time and had better overall hearing at the time of diagnosis. Reductions in the rates of various complications were also observed. These trends are felt to be the direct result of improved audiologic and radiologic diagnostic studies. A heightened awareness of all otolaryngologists to seek the diagnosis of acoustic neuroma also improved early diagnosis.
Towards the development of electronic learning and online tools: An experimental approach to specialist teacher education (Art and Design)
Authors: Davies Tom , Worrall Pete
Published: October 2006

This paper is part of continuing research into electronic learning in specialist Initial Teacher Training. It argues for a broader approach to the art and design curriculum that facilitates questions related to established content, systems and methods of teaching and learning. Advocating
a more experimental and analytical approach to the study of the subject, the research has supported both technical skills acquisition and the application of classroom discussion. More importantly, it has provided teaching models and methods that utilize digital technology as a visual research
tool. It could be argued that Information and Communication Technology (ICT) is a potentially powerful means of questioning, critiquing convention, orthodoxy and the general predictability of much of what counts as school art practice.
Book Review
Authors: Economidou Marina , Toner-Edgar Maggi , Kennard Alison , O'Riordan Kate
Published: October 2006

Problem-based Learning in Higher Education: Untold Stories by Maggi Savin-Baden Edited

Problem-based Learning: case studies, experience and practice Editors: Peter Schwartz, Stewart Mennin and Graham Webb

Online Learning and Teaching with Technology Case Studies,
Experience and Practice Edited by David Murphy, Rob Walker and Graham Webb

A Transactional Perspective on Teaching and Learning: A Framework for Adult and Higher Education by D. Randy Garrison and Walter Archer

Feminist Media Studies (Volume 1 Numbers 1, 2 and 3 March, July and November
2001) Edited by Cynthia Carter and Lisa McLaughlin
Doctoral education in design, the process of research degree study, and the trained researcher
Authors: Newbury Darren
Published: October 2006

Whilst the contribution to knowledge has long been understood as an outcome of doctoral research, in more recent times the spotlight has increasingly shifted to that other outcome of doctoral education: the trained researcher. The aim of this paper, similarly, is to set aside the epistemological
and definitional issues that surround any notion of design knowledge and how one contributes to it, in favour of a focus on the process of studying for a research degree, the knowledge and skills one might reasonably expect research students to acquire, and the structuring of doctoral training
programmes.

Drawing on recent papers and policy documents in this area, as well as personal experience of developing a formal postgraduate research training programme, the paper identifies three key areas for consideration in the development of new doctoral training programmes for design.
First, preparation for research degree studies. Second, the development of competence in research skills and procedures, including associated research career skills. Third, the promotion of methodological reflexivity. The paper expands on the implications of each for the structure and content
of research training programmes in design. The intention is not to develop a definitive programme for doctoral education; rather it is to set out a framework for the discussion of a diversity of practices.
The Impact of the Prevailing Business Culture on Entrepreneurial Activity and Small Businesses: A Contrastive Study of Spain and the USA
Authors: Rollin Hilary , Richardson Rosemary
Published: October 2006

The correlation between small business activity and economic growth is well documented. It is also widely held that a key influence on the level of entrepreneurship and the success rate of small businesses is the prevailing business culture, yet the features of this are seldom defined.
This article examines the contribution made by small businesses in various sectors of Spain's economy, reviewing factors highlighted by interviewees in case studies as instrumental to the success, or otherwise, of specific enterprises. It then turns to case studies conducted in the USA in
an attempt to pinpoint the factors contributing there to the prevailing business culture and to determine what can be learnt from the longer-established North American experience of entrepreneurship.
Networks of Innovation: Science, Technology and Development in the Triple Helix Era
Authors: Etzkowitz Henry
Published: October 2006

There is a common movement, from different starting points in various countries, to achieve knowledge-based economic and social development. The heart of the triple helix thesis is an expansion of the role of knowledge in society and of the university in the economy. The university
is undergoing a dual transformation: an expansion of missions to include economic and social development as well as training, cultural reproduction and research and a shift from an individual to an organisational focus in each mission. The triple helix thesis of relations among university,
industry and government is proposed as a development strategy to fill social capital as well as technology gaps. European Union and Canadian networked R&D schemes and the growth of firm-formation and incubation, especially in Brazilian networked incubators, exemplify the realization of
the triple helix network as a development model.
Russian Cinema in troubled times
Authors: Lawton Anna
Published: October 2006

The end of the Soviet era opened a period of financial distress and artistic disorientation in the film industry. The transition to the free market was too abrupt; price liberalization, privatization, the collapse of the centralized system of production and distribution, the deterioration
of the studios, inadequate law enforcement to guarantee copyright, rampant video piracy, and the general decline of disposable income among the population combined to push film production down to an alarming low. The films of shock capitalism do not easily fall into a trend or a movement.
Many reassess the past, placing different spins on various epochs and figures according to the director's ideological orientation. Others reflect the reality of the present day, either in dramatic or grotesque form. Still others offer escapism into imaginary worlds. About 50 films are surveyed
here. They vary in production values and intellectual level, but each is a document of the specific time and place in which it was produced. Each film, therefore, is relevant as a cultural product of this bizarre Russian fin de sicle.
Stepwise carcinogenesis of hepatocellular carcinoma in the cirrhotic liver: Demonstration on serial MR imaging
Authors: van den Bos Indra C. , Hussain Shahid M. , Terkivatan Türkan , Zondervan Pieter E. , de Man Robert A.
Published: October 2006

Purpose

To demonstrate imaging findings of stepwise carcinogenesis of hepatocellular carcinoma (HCC) in cirrhosis at serial state‐of‐the‐art MR imaging exams.

Materials and Methods

In a retrospective search of the hospital archives, three patients were identified in which developing HCC was observed in serial MR examinations, with histopathology or alpha‐fetoprotein (AFP) correlation. Image findings were assessed for signal intensity of the lesions at multiple sequences, including dynamic gadolinium‐enhanced imaging.

Results

Initial findings in patient A showed a small nodule with fatty infiltration that developed in HCC in follow‐up MRI, comprised of low‐grade dysplastic nodule (DN; DN I), high‐grade DN (DN II), and eventually classic HCC. In patient B, increased signal intensity on T2‐weighted images in a single DN among numerous regenerative nodules was the only initial sign. Follow up MRI showed further increase in signal intensity and increased neovascularity, which suggested focal HCC in a DN II. Patient C demonstrated gradually increasing neovascularity as only initial sign, with development of classic HCC over time.

Conclusion

MR imaging provides insight in various pathways of stepwise carcinogenesis of developing HCC in cirrhosis. This may further explain the genetic heterogeneity, and may facilitate early detection and better selection of patients for follow‐up. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
The Royal College of Art: a Study in Modern Architecture and Urbanism
Authors: Dunnett James
Published: October 2006

Cadbury-Brown's designs for new buildings for the Royal College of Art offer fascinating insights into both his own development and wider professional and social contexts.
Determination of rotational and vibrational temperatures of a nitrogen helicon plasma
Authors: Biloiu Costel , Sun Xuan , Harvey Zane , Scime Earl
Published: October 2006

We present a method of rotational and vibrational temperature estimation in nitrogen plasma by simulation of the emission spectrum of the first positive system (BΠg3→AΣu+3) of nitrogen. The gas kinetic temperature, assumed to be in equilibrium with the rotational temperature, was obtained from a fit to the experimentally obtained 0→0 at 1051nm, 1→0 at 872.23nm, and 2→0 at 775.32nm rovibrational band spectra. Excellent agreement between values inferred from each band [(499±29)K] as well as inferred by using the 3→0 band peak ratio method [(473±25)K] was obtained for a 600W, 850G, and 10mTorr helicon N2 plasma. The vibrational temperature was determined from a Boltzmann plot of the integrated band intensities [(6040±225)K] and by numerical fit to the Δv=+1, +2, and +3 sequences after accounting for Franck-Condon factors and electronic-vibrational transition moments [(6200±400)K].