ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Annual Reviews
  • 2015-2019
  • 2005-2009
  • 1995-1999  (980)
  • 1985-1989
  • 1980-1984
  • 1997  (980)
Sammlung
Verlag/Herausgeber
Erscheinungszeitraum
  • 2015-2019
  • 2005-2009
  • 1995-1999  (980)
  • 1985-1989
  • 1980-1984
Jahr
  • 1
    Digitale Medien
    Digitale Medien
    WHATEVER HAPPENED TO THE FUN? An Autobiographical Investigation (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 1-25 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.1
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    STRUCTURAL AND MECHANISTIC DETERMINANTS OF AFFINITY AND SPECIFICITY OF LIGANDS DISCOVERED OR ENGINEERED BY PHAGE DISPLAY (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 27-45 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract The scope and utility of phage display is reviewed with emphasis on medical applications and structure-based ligand and drug design, from literature mostly after 1994. General principles by which phage-displayed peptides achieve affinity and selectivity for targets are described, along with selected structural or mechanistic studies of the binding of peptides or proteins discovered or engineered by phage display. Such engineered proteins whose wild-type or mutant crystal or 2D-NMR structures yield insight about the basis for enhanced affinity or altered specificity include antibodies, zinc fingers, human growth hormone, protein A, and atrial natriuretic peptide. Structures of complexes of de novo phage-discovered peptide ligands with targets such as the Src SH3 domain, streptavidin, and erythropoietin receptor reveal the structural basis for receptor-peptide recognition in these systems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.27
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    HISTONE STRUCTURE AND THE ORGANIZATION OF THE NUCLEOSOME (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 83-112 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Chromatin structure is now believed to be dynamic and intimately related with cellular processes such as transcription. Over the past few years, high-resolution structures for the histones have become available. These structures and their implications for nucleosome organization are reviewed here.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.83
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    HIERARCHY AND DYNAMICS OF RNA FOLDING (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 113-137 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract The evidence showing that the self-assembly of complex RNAs occurs in discrete transitions, each relating to the folding of sub-systems of increasing size and complexity starting from a state with most of the secondary structure, is reviewed. The reciprocal influence of the concentration of magnesium ions and nucleotide mutations on tertiary structure is analyzed. Several observations demonstrate that detrimental mutations can be rescued by high magnesium concentrations, while stabilizing mutations lead to a lesser dependence on magnesium ion concentration. Recent data point to the central controlling and monitoring roles of RNA-binding proteins that can bind to the different folding stages, either before full establishment of the secondary structure or at the molten globule state before the cooperative transition to the final three-dimensional structure.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.113
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    FLEXIBILITY OF RNA (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 139-156 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract One of the fundamental properties of the RNA helix is its intrinsic resistance to bend- or twist-deformations. Results of a variety of physical measurements point to a persistence length of 700-800 A for double-stranded RNA in the presence of magnesium cations, approximately 1.5-2.0-fold larger than the corresponding value for DNA. Although helix flexibility represents an important, quantifiable measure of the forces of interaction within the helix, it must also be considered in describing conformational variation of nonhelix elements (e.g. internal loops, branches), since the latter always reflect the properties of the flanking helices; that is, such elements are never completely rigid. For one important element of tertiary structure, namely, the core of yeast tRNAPhe, the above consideration has led to the conclusion that the core is not substantially more flexible than an equivalent length of pure helix.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.139
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    STRUCTURAL PERSPECTIVES OF PHOSPHOLAMBAN, A HELICAL TRANSMEMBRANE PENTAMER (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 157-179 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Phospholamban is a 52-amino-acid protein that assembles into a pentamer in sarcoplasmic reticulum membranes. The protein has a role in the regulation of the resident calcium ATPase through an inhibitory association that can be reversed by phosphorylation. The phosphorylation of phospholamban is initiated by beta-adrenergic stimulation, identifying phospholamban as an important component in the stimulation of cardiac activity by beta-agonists. It is this role of phospholamban that has motivated studies in recent decades. There is evidence that phospholamban may also function as a Ca2+-selective ion channel. The structural properties of phospholamban have been studied by mutagenesis, modeling, and spectroscopy, resulting in a new view of the organization of this key molecule in membranes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.157
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    BIOMOLECULAR DYNAMICS AT LONG TIMESTEPS:Bridging the Timescale Gap Between Simulation and Experimentation (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 181-222 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Innovative algorithms have been developed during the past decade for simulating Newtonian physics for macromolecules. A major goal is alleviation of the severe requirement that the integration timestep be small enough to resolve the fastest components of the motion and thus guarantee numerical stability. This timestep problem is challenging if strictly faster methods with the same all-atom resolution at small timesteps are sought. Mathematical techniques that have worked well in other multiple-timescale contexts-where the fast motions are rapidly decaying or largely decoupled from others-have not been as successful for biomolecules, where vibrational coupling is strong. This review examines general issues that limit the timestep and describes available methods (constrained, reduced-variable, implicit, symplecttic, multiple-timestep, and normal-mode-based schemes). A section compares results of selected integrators for a model dipeptide, assessing physical and numerical performance. Included is our dual timestep method LN, which relies on an approximate linearization of the equations of motion every Deltat interval (5 fs or less), the solution of which is obtained by explicit integration at the inner timestep Deltatau (e.g., 0.5 fs). LN is computationally competitive, providing 4-5 speedup factors, and results are in good agreement, in comparison to 0.5 fs trajectories. These collective algorithmic efforts help fill the gap between the time range that can be simulated and the timespans of major biological interest (milliseconds and longer). Still, only a hierarchy of models and methods, along with experimentational improvements, will ultimately give theoretical modeling the status of partner with experiment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.181
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    MOLECULAR MECHANISM OF PHOTOSIGNALING BY ARCHAEAL SENSORY RHODOPSINS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 223-258 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Two sensory rhodopsins (SRI and SRII) mediate color-sensitive phototaxis responses in halobacteria. These seven-helix receptor proteins, structurally and functionally similar to animal visual pigments, couple retinal photoisomerization to receptor activation and are complexed with membrane-embedded transducer proteins (HtrI and HtrII) that modulate a cytoplasmic phosphorylation cascade controlling the flagellar motor. The Htr proteins resemble the chemotaxis transducers from Escherichia coli. The SR-Htr signaling complexes allow studies of the biophysical chemistry of signal generation and relay, from the photobiophysics of initial excitation of the receptors to the final output at the level of the flagellar motor switch, revealing fundamental principles of sensory transduction and more broadly the nature of dynamic interactions between membrane proteins. We review here recent advances that have led to new insights into the molecular mechanism of signaling by these membrane complexes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.223
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    MODULAR PEPTIDE RECOGNITION DOMAINS IN EUKARYOTIC SIGNALING (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 259-288 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract A characteristic feature of cellular signal transduction pathways in eukaryotes is the separation of catalysis from target recognition. Several modular domains that recognize short peptide sequences and target signaling proteins to these sequences have been identified. The structural bases of the specificities of recognition by SH2, SH3, and PTB domains have been elucidated by X-ray crystallography and NMR, and these results are reviewed here. In addition, the mechanism of cooperative interactions between these domains is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.259
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    LESSONS FROM ZINC-BINDING PEPTIDES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 357-371 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Zinc-finger domains are small metal-binding modules that are found in a wide range of gene regulatory proteins. Peptides corresponding to these domains have provided valuable model systems for examining a number of biophysical parameters entirely unrelated to their nucleic acid binding properties. These include the chemical basis for metal-ion affinity and selectivity, thermodynamic properties related to hydrophobic packing and beta-sheet propensities, and constraints on the generation of ligand-binding and potential catalytic sites. These studies have laid the foundation for applications such as the generation of optically detected zinc probes and the design of metal-binding peptides and proteins with desired spectroscopic and chemical properties.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.357
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 11
    Digitale Medien
    Digitale Medien
    NANOSECOND TIME-RESOLVED SPECTROSCOPY OF BIOMOLECULAR PROCESSES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 327-355 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Over the past two decades, nanosecond absorption and vibrational spectroscopies have developed into powerful tools for monitoring the secondary, tertiary, and quaternary structural relaxations of biological macromolecules under near-physiological conditions of solvent and temperature. Observed through such methods, the dynamic response of a biomolecule to photoinitiated excursions from equilibrium can reveal valuable information about the structure-function relationship, information beyond that obtained from the static structures provided by X-ray crystallography, nuclear magnetic resonance spectroscopy, and other steady-state methods. Most recently, the development of ultra-sensitive polarization techniques for absorption spectroscopy has greatly enhanced the amount of time-resolved structural information that can be obtained from the broadened electronic spectra of biomolecules. This review examines nanosecond absorption, vibrational, and polarized absorption methods, and their applications to protein function and folding, emphasizing the complementary nature of information obtained from electronic and vibrational spectra measured on the nanosecond time scale.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.327
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 12
    Digitale Medien
    Digitale Medien
    EUKARYOTIC TRANSCRIPTION FACTOR-DNA COMPLEXES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 289-325 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Eukaryotes have three distinct RNA polymerases that catalyze transcription of nuclear genes. RNA polymerase II is responsible for transcribing nuclear genes encoding the messenger RNAs and several small nuclear RNAs. Like RNA polymerases I and III, polymerase II cannot recognize its target promoter directly and initiate transcription without accessory factors. Instead, this large multisubunit enzyme relies on general transcription factors and transcriptional activators and coactivators to regulate transcription from class II promoters. X-ray crystallography and nuclear magnetic resonance spectroscopy have been used to study complexes of general transcription factors and transcriptional activators with their specific DNA targets. This work has provided important structural insights into transcription initiation by polymerase II and the more general problem of DNA sequence recognition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.289
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 13
    Digitale Medien
    Digitale Medien
    CALCIUM IN CLOSE QUARTERS:Microdomain Feedback in Excitation-Contraction Coupling and Other Cell Biological Phenomena (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 47-82 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Researchers have made good progress in unraveling the molecular mechanisms of excitation-contraction (EC) coupling in striated muscle. Despite this progress, paradoxes abound. In skeletal muscle, the existence of a mechanical coupling between membrane charge movement and activation of sarcoplasmic reticulum (SR) release channels is essentially established, but the contribution of Ca2+-induced Ca2+ release (CICR) to the transient and steady-state components of Ca2+ release remains controversial. In cardiac muscle, the role of CICR as the primary mechanism of EC coupling is well established, but the stability and tight coupling between membrane Ca2+ current and release are paradoxical. Answers may lie in microdomain issues, and in the examination of discrete elementary release events, although quantitative treatments are needed. This review explores the theoretical and experimental methods used and the observations made in the study of microdomain Ca2+.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.47
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 14
    Digitale Medien
    Digitale Medien
    SINGLE-PARTICLE TRACKING:Applications to Membrane Dynamics (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 373-399 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Measurements of trajectories of individual proteins or lipids in the plasma membrane of cells show a variety of types of motion. Brownian motion is observed, but many of the particles undergo non-Brownian motion, including directed motion, confined motion, and anomalous diffusion. The variety of motion leads to significant effects on the kinetics of reactions among membrane-bound species and requires a revision of existing views of membrane structure and dynamics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.373
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 15
    Digitale Medien
    Digitale Medien
    ADVANCED EPR SPECTROSCOPY ON ELECTRON TRANSFER PROCESSES IN PHOTOSYNTHESIS AND BIOMIMETIC MODEL SYSTEMS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 495-540 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract This review focuses on the recent advances in EPR spectroscopy as they are applied both to photoinduced electron transfer in the photosynthetic apparatus and to biomimetic systems. The review deals with time-resolved direct-detection cw and pulsed EPR and ENDOR methods, both at conventional bands [X-(9.5 GHz), K-(24 GHz), and Q-(35 GHz)] and at high frequency bands (W-band, 95 GHz, and even highter frequency bands). EPR studies on photosynthetic and model systems in their doublet, triplet and radical pair states are surveyed, including their static and dynamic properties. Applications of time-resolved EPR in studying photoinduced electron and energy transfer in isotropic and anisotropic environments, and the concepts of electron spin polarization and magnetic field effects in photochemical reactions are also reviewed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.495
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 16
    Digitale Medien
    Digitale Medien
    USE OF SURFACE PLASMON RESONANCE TO PROBE THE EQUILIBRIUM AND DYNAMIC ASPECTS OF INTERACTIONS BETWEEN BIOLOGICAL MACROMOLECULES1 (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 541-566 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Surface plasmon resonance biosensors have become increasingly popular for the qualitative and quantitative characterization of the specific binding of a mobile reactant to a binding partner immobilized on the sensor surface. This article reviews the use of this new technique to measure the binding affinities and the kinetic constants of reversible interactions between biological macromolecules. Immobilization techniques, the most commonly employed experimental strategies, and various analytical approaches are summarized. In recent years, several sources of potential artifacts have been identified: immobilization of the binding partner, steric hindrance of binding to adjacent binding sites at the sensor surface, and finite rate of mass transport of the mobile reactant to the sensor surface. Described here is the influence of these artifacts on the measured binding kinetics and equilibria, together with suggested control experiments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.541
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 17
    Digitale Medien
    Digitale Medien
    PROTEIN FOLDS IN THE ALL-beta AND ALL-alpha CLASSES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 597-627 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Analysis of the structures in the Protein Databank, released in June 1996, shows that the number of different protein folds, i.e. the number of different arrangements of major secondary structures and/or chain topologies, is 327. Of these folds, approximately 25% belong to the all-alpha class, 20% belong to the all-beta class, 30% belong to the alpha/beta class, and 25% belong to the alpha + beta class. We describe the types of folds now known for the all-beta and all-alpha classes, emphasizing those that have been discovered recently. Detailed theories for the physical determinants of the structures of most of these folds now exist, and these are reviewed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.597
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 18
    Digitale Medien
    Digitale Medien
    GENETICS OF TRANSCRIPTIONAL REGULATION IN YEAST: Connections to the RNA Polymerase II CTD (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 1-23 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Transcriptional regulation is important in all eukaryotic organisms for cell growth, development, and responses to environmental change. Saccharomyces cerevisiae, or bakers' yeast, has provided a powerful system for genetic analysis of transcriptional regulation, and findings from the study of this model system have proven broadly applicable to higher organisms. Transcriptional regulation requires the interactions of regulatory proteins with various components of the transcription machinery. Recently, genetic analysis of a diverse set of transcriptional regulatory responses has converged with studies of the function of the RNA polymerase II carboxy-terminal domain (CTD) to reveal regulatory roles for proteins associated with the CTD. These proteins, designated Srb/mediator proteins, are broadly involved in both positive and negative regulatory responses in vivo. This review focuses on the connections between genetic analysis of transcriptional regulation and the functions of the Srb/mediator proteins associated with the RNA polymerase II CTD.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.1
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 19
    Digitale Medien
    Digitale Medien
    LEFT-RIGHT ASYMMETRY IN ANIMAL DEVELOPMENT (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 53-82 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Most animal species exhibit left-right asymmetry in their body plans and show a strong bias for one handedness over the other. The mechanism of handedness choice, recognized as an intriguing problem over a century ago, is still a mystery. However, from recent advances in understanding when and how asymmetry arises in both invertebrates and vertebrates, developmental pathways for establishment and maintenance of left-right differences are beginning to take shape, and speculations can be made on the initial choice mechanism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.53
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 20
    Digitale Medien
    Digitale Medien
    MICROTUBULE POLYMERIZATION DYNAMICS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 83-117 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract The polymerization dynamics of microtubules are central to their biological functions. Polymerization dynamics allow microtubules to adopt spatial arrangements that can change rapidly in response to cellular needs and, in some cases, to perform mechanical work. Microtubules utilize the energy of GTP hydrolysis to fuel a unique polymerization mechanism termed dynamic instability. In this review, we first describe progress toward understanding the mechanism of dynamic instability of pure tubulin and then discuss the function and regulation of microtubule dynamic instability in living cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.83
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 21
    Digitale Medien
    Digitale Medien
    MITOCHONDRIAL PREPROTEIN TRANSLOCASE (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 25-51 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Mitochondria import most of their proteins from the cytosol. Dynamic protein complexes in the mitochondrial outer and inner membranes are responsible for the specific recognition and membrane translocation of preproteins. The preprotein translocase of the outer mitochondrial membrane contains several import receptors and a general import pore. The preprotein translocase of the inner membrane consists of a channel interacting with preproteins in transit and an import motor that includes the matrix heat shock protein Hsp70. Acidic patches of import components are thought to guide the import of positively charged signal sequences (acid chain hypothesis). Energy input is derived from the inner membrane potential and ATP. Proteins in the mitochondrial matrix are required for proteolytic processing and folding of imported proteins. The dynamic nature of the membrane translocase permits sorting of preproteins at distinct stages of the import pathway.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.25
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 22
    Digitale Medien
    Digitale Medien
    MOLECULAR AND FUNCTIONAL ANALYSIS OF CADHERIN-BASED ADHERENS JUNCTIONS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 119-146 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Adherens junctions are specialized forms of cadherin-based adhesive contacts important for tissue organization in developing and adult organisms. Cadherins form protein complexes with cytoplasmic proteins (catenins) that convert the specific, homophilic-binding capacity of the extracellular domain into stable cell adhesion. The extracellular domains of cadherins form parallel dimers that possess intrinsic homophilic-binding activity. Cytoplasmic interactions can influence the function of the ectodomain by a number of potential mechanisms, including redistribution of binding sites into clusters, providing cytoskeletal anchorage, and mediating physiological regulation of cadherin function. Adherens junctions are likely to serve specific, specialized functions beyond the basic adhesive process. These functions include coupling cytoskeletal force generation to strongly adherent sites on the cell surface and the regulation of intracellular signaling events.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.119
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 23
    Digitale Medien
    Digitale Medien
    GENETIC ANALYSIS OF THE ACTIN CYTOSKELETON IN THE DROSOPHILA OVARY (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 147-170 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract The Drosophila ovary provides a favorable model system in which to study cellular morphogenesis. The development of a mature egg involves a syncytium of 16 germline cells and over 1000 somatically derived follicle cells. Intercellular transport, stable intercellular bridges, cell migrations, cell shape changes, and specific subcellular localization of many embryonic patterning determinants contribute to egg development and require a dynamic cytoskeleton. We discuss many of the recent genetic and cell biological studies that have led to insights into how the actin cytoskeleton is assembled and regulated during the morphogenesis of the Drosophila egg.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.147
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 24
    Digitale Medien
    Digitale Medien
    THE LIN-12/Notch SIGNALING PATHWAY AND ITS REGULATION (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 333-361 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Notch, LIN-12, and GLP-1 are receptors that mediate a broad range of cell interactions during Drosophila and nematode development. Signaling by these receptors relies on a conserved pathway with three core components: DSL ligand, LNG receptor, and a CSL effector that links the receptor to its transcriptional response. Although key functional regions have been identified in each class of proteins, the mechanism for signal transduction is not yet understood. Diverse regulatory mechanisms influence signaling by the LIN-12/Notch pathway. Inductive signaling relies on the synthesis of ligand and receptor in distinct but neighboring cells. By contrast, lateral signaling leads to the transformation of equivalent cells that express both ligand and receptor into nonequivalent cells that express either ligand or receptor. This transformation appears to rely on regulatory feedback loops within the LIN-12/Notch pathway. In addition, the pathway can be regulated by intrinsic factors that are asymmetrically segregated during cell division or by extrinsic cues via other signaling pathways. Specificity in the pathway does not appear to reside in the particular ligand or receptor used for a given cell-cell interaction. The existence of multiple ligands and receptors may have evolved from the stringent demands placed upon the regulation of genes encoding them.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.333
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 25
    Digitale Medien
    Digitale Medien
    IMPLICATIONS OF ATOMIC-RESOLUTION STRUCTURES FOR CELL ADHESION (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 363-393 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Molecules involved in cell adhesion processes are often both structurally and functionally modular, with subdomains that are members of large protein families. Recently, high-resolution structures have been determined for representative members of many of these families including fragments of integrins, cadherins, fibronectin-like domains, and immunoglobulin-like domains. These structures have enhanced our understanding of cell adhesion processes at several levels. In almost all cases, ligand-binding sites have been visualized and provide insight into how these molecules mediate biologically important interactions. Metal-binding sites have been identified and characterized, allowing assessment of the role of bound ions in cell adhesion processes. Many of these structures serve as templates for modeling homologous domains in other proteins or, when the structure of a fragment consisting of more than one domain is determined, the structure of multidomain arrays of homologous domains. Knowledge of atomic structure also allows rational design of drugs that either mimic or target specific binding sites. In many cases, high-resolution structures have revealed unexpected relationships that pose questions about the evolutionary origin of specific domains. This review briefly describes several recently determined structures of cell adhesion molecules, summarizes some of the main results of each structure, and highlights common features of different systems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.363
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 26
    Digitale Medien
    Digitale Medien
    BACTERIAL CELL DIVISION (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 395-424 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Bacteria usually divide by building a central septum across the middle of the cell. This review focuses on recent results indicating that the tubulin-like FtsZ protein plays a central role in cytokinesis as a major component of a contractile cytoskeleton. Assembly of this cytoskeletal element abutting the membrane is a key point for regulation. The characterization of FtsZ homologues in Mycoplasmas, Archaea, and chloroplasts implies that the constriction mechanism is conserved and that FtsZ can constrict in the absence of peptidoglycan synthesis. In most Eubacteria, the internal cytoskeleton must also regulate synthesis of septal peptidoglycan. The Escherichia coli septum-specific penicillin-binding protein 3 (PBP3) forms a complex with other enzymes involved in murein metabolism, suggesting a centrally located transmembrane complex capable of splicing multiple new strands of peptidoglycan into the cell wall. Important questions remain about the spatial and temporal control of bacterial division.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.395
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 27
    Digitale Medien
    Digitale Medien
    NEURAL CELL ADHESION MOLECULES OF THE IMMUNOGLOBULIN SUPERFAMILY: Role in Axon Growth and Guidance (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 425-456 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract NCAM, L1, and DCC-immunoglobulin cell adhesion molecules (Ig CAMs)-are widely expressed during development. Many workers have dismissed a role for such molecules in the control of axonal growth and guidance because they do not show highly restricted expression patterns. Yet evidence from a number of model systems suggests all three CAMs play a role in the development of specific projections in the nervous system. For example, there is a reduction in mossy fiber tracts in the hippocampus of mice that lack NCAM, a requirement for DCC in the response of commissural neurons to a floor plate-derived chemoattractant, and a loss of corticospinal tracts in humans who carry mutations in the L1 gene. The above paradox might be explained by the observation that differential post-translational processing can modulate CAMs function and that alternative splicing can generate functionally distinct isoforms of a CAM. Activation of the FGF tyrosine kinase receptor is required for the responses stimulated by NCAM and L1, and the importance of regulated tyrosine phosphorylation for growth and guidance is underscored by the involvement of receptor tyrosine phosphatases in this process.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.425
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 28
    Digitale Medien
    Digitale Medien
    CELLULAR FUNCTIONS REGULATED BY SRC FAMILY KINASES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 513-609 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Src family protein tyrosine kinases are activated following engagement of many different classes of cellular receptors and participate in signaling pathways that control a diverse spectrum of receptor-induced biological activities. While several of these kinases have evolved to play distinct roles in specific receptor pathways, there is considerable redundancy in the functions of these kinases, both with respect to the receptor pathways that activate these kinases and the downstream effectors that mediate their biological activities. This chapter reviews the evidence implicating Src family kinases in specific receptor pathways and describes the mechanisms leading to their activation, the targets that interact with these kinases, and the biological events that they regulate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.513
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 29
    Digitale Medien
    Digitale Medien
    THE TWO-COMPONENT SIGNALING PATHWAY OF BACTERIAL CHEMOTAXIS: A Molecular View of Signal Transduction by Receptors, Kinases, and Adaptation Enzymes (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 457-512 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract The chemosensory pathway of bacterial chemotaxis has become a paradigm for the two-component superfamily of receptor-regulated phosphorylation pathways. This simple pathway illustrates many of the fundamental principles and unanswered questions in the field of signaling biology. A molecular description of pathway function has progressed rapidly because it is accessible to diverse structural, biochemical, and genetic approaches. As a result, structures are emerging for most of the pathway elements, biochemical studies are elucidating the mechanisms of key signaling events, and genetic methods are revealing the intermolecular interactions that transmit information between components. Recent advances include (a) the first molecular picture of a conformational transmembrane signal in a cell surface receptor, (b) four new structures of kinase domains and adaptation enzymes, and (c) significant new insights into the mechanisms of receptor-mediated kinase regulation, receptor adaptation, and the phospho-activation of signaling proteins. Overall, the chemosensory pathway and the propulsion system it regulates provide an ideal system in which to probe molecular principles underlying complex cellular signaling and behavior.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.457
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 30
    Digitale Medien
    Digitale Medien
    FORMATION AND FUNCTION OF SPEMANN'S ORGANIZER (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 611-667 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract The organizer is formed in an equatorial sector of the blastula stage amphibian embryo by cells that have responded to two maternal agents: a general meso-endoderm inducer (involving the TFG-beta signaling pathway) and a dorsal modifier (probably involving the Wnt signaling pathway). The meso-endoderm inducer is secreted by most vegetal cells, those containing maternal materials that had been localized in the vegetal hemisphere of the oocyte during oogenesis. As a consequence of the inducer's distribution and action, the competence domains of prospective ectoderm, mesoderm, and endoderm are established in an animal-to-vegetal order in the blastula. The dorsal modifier signal is secreted by a sector of cells of the animal and vegetal hemispheres on one side of the blastula. These cells contain maternal materials transported there in the first cell cycle from the vegetal pole of the egg along microtubules aligned by cortical rotation. The Nieuwkoop center is the region of blastula cells secreting both maternal signals, and hence specifying the organizer in an equatorial sector. Final steps of organizer formation at the late blastula or early gastrula stage may involve locally secreted zygotic signals as well. At the gastrula stage, the organizer secretes a variety of zygotic proteins that act as antagonists to various members of the BMP and Wnt families of ligands, which are secreted by cells of the competence domains surrounding the organizer. BMPs and Wnts favor ventral development, and cells near the organizer are protected from these agents by the organizer's inducers. The nearby cells are derepressed in their inherent capacity for dorsal development, which is apparent in the neural induction of the ectoderm, dorsalization of the mesoderm, and anteriorization of the endoderm. The organizer also engages in extensive specialized morphogenesis, which brings it within range of responsive cell groups. It also self-differentiates to a variety of axial tissues of the body.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.611
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 31
    Digitale Medien
    Digitale Medien
    A PHYSICIST COURTS ASTRONOMY (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. xiii 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.0
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 32
    Digitale Medien
    Digitale Medien
    THE SUN'S VARIABLE RADIATION AND ITS RELEVANCE FOR EARTH1 (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 33-67 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract To what extent are changes in the Earth's global environment linked with fluctuations in its primary energy source, the radiation from a variable star, the Sun? A firm scientific basis for policy making with regard to anthropogenic greenhouse warming of climate and chlorofluorocarbon depletion of ozone requires a reliable answer to this question. Reduction of the vulnerability of spacecraft operations and communications to space weather necessitates knowledge of solar induced variability in Earth's upper atmosphere. Toward these goals, solar radiation monitoring and studies of solar variability mechanisms facilitate an understanding of the sources and amplitudes of the Sun's changing radiation. Interdisciplinary studies that link these changes with a wide array of terrestrial phenomena over the longer time scales of global change and the shorter time scales of space weather address the relevance of solar radiation variability for Earth. However, although numerous associations are apparent between solar and terrestrial fluctuations, full comprehension of the physical mechanisms responsible for the many facets of radiative Sun-Earth coupling remains to be accomplished.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.33
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 33
    Digitale Medien
    Digitale Medien
    LOW SURFACE BRIGHTNESS GALAXIES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 267-307 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract The properties of galaxies that are lower in surface brightness than the dark night sky are reviewed. There are substantial selection effects against the discovery of galaxies that are unevolved or diffuse; these systems are missing from most wide field catalogs. Low surface brightness galaxies make up a significant amount of the luminosity density of the local universe. They contribute substantial but poorly determined amounts to the census of baryons and dark matter. Low surface brightness galaxies are also relevant to the interpretation of quasar absorption lines and to the understanding of rapidly evolving galaxy populations in the more distant universe. Theories of galaxy formation and evolution must accomodate the properties of these diffuse stellar systems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.267
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 34
    Digitale Medien
    Digitale Medien
    COMPACT GROUPS OF GALAXIES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 357-388 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract Compact groups of galaxies have posed a number of challenging questions. Intensive observational and theoretical studies are now providing answers to many of these and, at the same time, are revealing unexpected new clues about the nature and role of these systems. Most compact groups contain a high fraction of galaxies having morphological or kinematical peculiarities, nuclear radio and infrared emission, and starburst or active galactic nuclei (AGN) activity. They contain large quantities of diffuse gas and are dynamically dominated by dark matter. They most likely form as subsystems within looser associations and evolve by gravitational processes. Strong galaxy interactions result and merging is expected to lead to the ultimate demise of the group. Compact groups are surprisingly numerous and may play a significant role in galaxy evolution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.357
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 35
    Digitale Medien
    Digitale Medien
    MIXING IN STARS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 557-605 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract Three cases for mixing not present in standard stellar models are presented: Light element depletion in low mass main-sequence stars, deep mixing in massive stars, and deep mixing in low mass giants. The review begins with the mixing indicators and the predictions of standard models. The observational evidence for anomalous mixing is then presented, followed by the physics of mixing outside the standard model. The status of theoretical models that include extra mixing is then examined.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.557
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 36
    Digitale Medien
    Digitale Medien
    MODERN HELICOPTER AERODYNAMICS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 515-567 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract Modern helicopter aerodynamics is challenging because the flow field generated by a helicopter is extremely complicated and difficult to measure, model, and predict; moreover, experiments are expensive and difficult to conduct. In this article we discuss the basic principles of modern helicopter aerodynamics. Many sophisticated experimental and computational techniques have been employed in an effort to predict performance parameters. Of particular interest is the structure of the rotor wake, which is highly three-dimensional and unsteady, and the rotor-blade pressure distribution, which is significantly affected by the strength and position of the wake. We describe the various modern methods of computation and experiment which span the range from vortex techniques to full three-dimensional Navier-Stokes computations, and from classical probe methods to laser velocimetry techniques. Typical results for the structure of the wake and the blade pressure distribution in both hover and forward flight are presented Despite the complexity of the helicopter flow, significant progress has been made within the last ten years and the future will likely bring marked advances.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.515
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 37
    Digitale Medien
    Digitale Medien
    GENE TARGETING AND THE BIOLOGY OF LEARNING AND MEMORY (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 527-546 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract The general goal of genetic studies of learning and memory is to develop and test theories that explain the animal's behavior in neuroanatomical, neurophysiological, cellular, and molecular terms. In this review we describe the role that gene targeting and other transgenic techniques have had in the study of mammalian learning and memory. We focus especially on the hippocampus, a brain structure that is thought to be central to the processing and temporary storage of complex information. We also discuss the main issues that confront this young field, as well as our vision for its future.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.527
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 38
    Digitale Medien
    Digitale Medien
    GENETICS OF ERYTHROPOIESIS:Induced Mutations in Mice and Zebrafish (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 33-60 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Production of red blood cells (erythropoiesis) in the vertebrate embryo is critical to its survival and subsequent development. As red cells are the first blood cells to appear in embryogenesis, their origin reflects commitment of mesoderm to an hematopoietic fate and provides an avenue by which to examine the development of the hematopoietic system, including the hematopoietic stem cell (HSC). We discuss the genetics of erythropoiesis as studied in two systems: the mouse and zebrafish (Danio rerio). In the mouse, targeted disruption has established several genes as essential at different stages of hematopoiesis or erythroid precursor cell maturation. In the zebrafish, numerous mutants displaying a wide range of phenotypes have been isolated, although the affected genes are unknown. In comparing mouse knockout and zebrafish mutant phenotypes, we propose a pathway for erythropoiesis that emphasizes the apparent similarity of the mutants and the complementary nature of investigation in the two species. We speculate that further genetic studies in mouse and zebrafish will identify the majority of essential genes and define a regulatory network for hematopoiesis in vertebrates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.33
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 39
    Digitale Medien
    Digitale Medien
    GENETIC ANALYSIS OF CHLOROPHYLL BIOSYNTHESIS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 61-89 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract During this decade, there have been major advancements in the understanding of genetic loci involved in synthesis of the family of Mg-tetrapyrroles known as chlorophylls and bacteriochlorophylls. Molecular genetic analysis of Mg-tetrapyrrole biosynthesis was initiated by the performance of detailed sequence and mutational analysis of the photosynthesis gene cluster from Rhodobacter capsulatus. These studies provided the first detailed understanding of genes involved in bacteriochlorophyll a biosynthesis. In the short time since these studies were initiated, most of the chlorophyll biosynthesis genes have been identified by virtue of their ability to complement bacteriochlorophyll a biosynthesis mutants as well as by sequence homology comparisons. This review is centered on a discussion of our current understanding of bacterial, algal, and plant genes that code for enzymes in the Mg-branch of the tetrapyrrole biosynthetic pathway that are responsible for synthesis of chlorophylls and bacteriochlorophylls.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.61
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 40
    Digitale Medien
    Digitale Medien
    GENE AMPLIFICATION AND GENOMIC PLASTICITY IN PROKARYOTES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 91-111 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Gene amplification is a common feature of the genome of prokaryotic organisms. In this review, we analyze different instances of gene amplification in a variety of prokaryotes, including their mechanisms of generation and biological role. Growing evidence supports the concept that gene amplification be considered not as a mutation but rather as a dynamic genomic state related to the adaptation of bacterial populations to changing environmental conditions or biological interactions. In this context, the potentially amplifiable DNA regions impose a defined dynamic structure on the genome. If such structure has indeed been selected during evolution, it is a particularly challenging hypothesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.91
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 41
    Digitale Medien
    Digitale Medien
    BACTERIOPHAGE DISPLAY AND DISCOVERY OF PEPTIDE LEADS FOR DRUG DEVELOPMENT (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 401-424 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Phage display makes large-peptide diversity libraries readily attainable for identifying novel peptide ligands for receptors and other protein or non-protein targets. This technology kindles enthusiasm for the idea that large and protein-protein interaction surfaces (epitopes) can be distilled down to small pharmacophores. These may be accessible to organic scaffolding, yielding new orally active drugs that might otherwise have taken greater time and effort to be discovered through chemical-library screening. This review, though not comprehensive with respect to the explosive volume of phage display work over the last few years, focuses on recent developments in phage-displayed peptide technology.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.401
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 42
    Digitale Medien
    Digitale Medien
    SOLVATION: HOW TO OBTAIN MICROSCOPIC ENERGIES FROM PARTITIONING AND SOLVATION EXPERIMENTS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 425-459 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Oil-water partitioning, solubilities, and vapor pressure experiments on small-molecule compounds are often used as models to obtain energies for biomolecular modeling. For example, measured partition coefficients, K, are often inserted into the formula -RTlnK to obtain quantities thought to represent microscopic contact interaction free energies. We review evidence here that this procedure does not always give microscopically meaningful free energies. Some partitioning processes, particularly involving polymeric solvents such as octanol or hexadecane, are governed not only by translational entropies and contact interactions, but also by free energies resulting from changes in the conformations of the polymer chains upon solute insertion. The Flory-Huggins theory is more suitable for these situations than is the classical approach. We discuss the physical bases for both approaches.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.425
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 43
    Digitale Medien
    Digitale Medien
    THE STRUCTURAL AND FUNCTIONAL BASIS OF ANTIBODY CATALYSIS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 461-493 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Ten years have passed since the initial reports that antibodies could be programmed to have enzymatic activity by immunization with a transition-site analog. Much of the research over the last decade has focused on defining the scope and generality of antibody catalysis; however, during the past two years the first few crystal structures of catalytic antibody transition-state analogs have been reported. This review analyzes four such structures of catalytic antibodies that catalyze markedly different reactions, including ester hydrolysis, sulfide oxidation, and a pericyclic rearrangement. Structure-function relations for these catalysts are discussed and compared to the structure and function of natural enzymes, as well as the chemistry that occurs in solution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.461
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 44
    Digitale Medien
    Digitale Medien
    OPTICAL DETECTION OF SINGLE MOLECULES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 567-596 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract Recent advances in ultrasensitive instrumentation have allowed for the detection, identification, and dynamic studies of single molecules in the condensed phase. This measurement capability provides a new set of tools for scientists to address important current problems and to explore new frontiers in many scientific disciplines, such as chemistry, molecular biology, molecular medicine, and nanostructured materials. This review focuses on the methodologies and biological applications of single-molecule detection based on laser-induced fluorescence.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.567
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 45
    Digitale Medien
    Digitale Medien
    SITE-SPECIFIC DYNAMICS IN DNA:Experiments (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 26 (1997), S. 629-658 
    Details
    ISSN: 1056-8700
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Physik
    Notizen: Abstract This chapter reviews the dynamics information obtained from experimental magnetic resonance studies of site-specifically labeled duplex DNA. A previous review (43) discusses the dynamics of duplex DNA; it develops a theory that shows how magnetic resonance experiments are used to detect those dynamics. The methods for obtaining information about dynamics as well as a summary of what is now known about the site-specific dynamics of DNA are presented. This review contains two methods sections which present results using electron paramagnetic resonance and nuclear magnetic resonance active probes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.biophys.26.1.629
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 46
    Digitale Medien
    Digitale Medien
    LIGHT CONTROL OF PLANT DEVELOPMENT (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 203-229 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract To grow and develop optimally, all organisms need to perceive and process information from both their biotic and abiotic surroundings. A particularly important environmental cue is light, to which organisms respond in many different ways. Because they are photosynthetic and non-motile, plants need to be especially plastic in response to their light environment. The diverse responses of plants to light require sophisticated sensing of its intensity, direction, duration, and wavelength. The action spectra of light responses provided assays to identify three photoreceptor systems absorbing in the red/far-red, blue/near-ultraviolet, and ultraviolet spectral ranges. Following absorption of light, photoreceptors interact with other signal transduction elements, which eventually leads to many molecular and morphological responses. While a complete signal transduction cascade is not known yet, molecular genetic studies using the model plant Arabidopsis have led to substantial progress in dissecting the signal transduction network. Important gains have been made in determining the function of the photoreceptors, the terminal response pathways, and the intervening signal transduction components.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.203
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 47
    Digitale Medien
    Digitale Medien
    ADIPOCYTE DIFFERENTIATION AND LEPTIN EXPRESSION (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 231-259 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Adipose tissue has long been known to house the largest energy reserves in the animal body. Recent research indicates that in addition to this role, the adipocyte functions as a global regulator of energy metabolism. Adipose tissue is exquisitely sensitive to a variety of endocrine and paracrine signals, e.g. insulin, glucagon, glucocorticoids, and tumor necrosis factor (TNF), that combine to control both the secretion of other regulatory factors and the recruitment and differentiation of new adipocytes. The process of adipocyte differentiation is controlled by a cascade of transcription factors, most notably those of the C/EBP and PPAR families, which combine to regulate each other and to control the expression of adipocyte-specific genes. One such gene, i.e. the obese gene, was recently identified and found to encode a hormone, referred to as leptin, that plays a major role in the regulation of energy intake and expenditure. The hormonal and transcriptional control of adipocyte differentiation is discussed, as is the role of leptin and other factors secreted by the adipocyte that participate in the regulation of adipose homeostasis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.231
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 48
    Digitale Medien
    Digitale Medien
    ETA CARINAE AND ITS ENVIRONMENT (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 1-32 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract Eta Carinae (Eta) is one of the most remarkable of all well-studied stars and perhaps the most poorly understood. Observations with the Hubble Space Telescope and other modern instruments have solved a few of the mysteries concerning this object while opening a comparable number of new ones. In this review we first recount some essential background information concerning Eta, then we sketch most of the observational developments of the past few years, related to the star itself and to its ejecta. Throughout, we propose a series of specific unsolved observational and theoretical problems that seem especially interesting or important at this time.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.1
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 49
    Digitale Medien
    Digitale Medien
    MODEL ATMOSPHERES OF VERY LOW MASS STARS AND BROWN DWARFS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 137-177 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract As progressively cooler stellar and substellar objects are discovered, the presence first of molecules and then of condensed particulates greatly complicates the understanding of their physical properties. Accurate model atmospheres that include these processes are the key to establishing their atmospheric parameters. They play a crucial role in determining structural characteristics by setting the surface conditions of model interiors and providing transformations to the various observational planes. They can reveal the spectroscopic properties of brown dwarfs and help establish their detectability. In this paper, we review the current state-of-the-art theory and modeling of the atmospheres of very low mass stars, including the coolest known M dwarfs, M subdwarfs, and brown dwarfs, i.e. Teff〈= 4,000 K and -4.0 〈= [M/H] 〈= +0.0. We discuss ongoing efforts to incorporate molecular and grain opacities in cool stellar spectra, as well as the latest progress in (a) deriving the effective temperature scale of M dwarfs, (b) reproducing the lower main sequences of metal-poor subdwarfs in the halo and globular clusters, and (c) results of the models related to the search for brown dwarfs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.137
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 50
    Digitale Medien
    Digitale Medien
    DENSE PHOTODISSOCIATION REGIONS (PDRs)1 (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 179-215 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract All neutral atomic hydrogen gas and a large fraction of the molecular gas in the Milky Way Galaxy and external galaxies lie in PDRs, and PDRs are the origin of most of the nonstellar infrared (IR) and the millimeter CO emission from a galaxy. On the surfaces (Av〈 1-3) of interstellar clouds, the absorption of far ultraviolet (FUV) photons (hnu〈 13.6 eV) by gas and dust grains leads to intense emission of [C II] 158 mum, [O I] 63, 146 mum, and H2 rovibrational transitions, as well as IR dust continuum and polycyclic aromatic hydrocarbon (PAH) emission features. Deeper in PDRs, CO rotational and [C I] 370, 609 mum lines originate. The transition of H to H2 and C+ to CO occurs within PDRs. Theoretical models compared with observations diagnose such physical parameters as the density and temperature structure, the elemental abundances, and the FUV radiation field in PDRs. Applications include clouds next to H II regions, reflection nebulae, planetary nebulae, red giant outflows, circumstellar gas around young stars, diffuse clouds, the warm neutral medium (WNM), and molecular clouds in the interstellar radiation field: in summary, much of the interstellar medium in galaxies. This review focuses on dense PDRs in the Milky Way Galaxy. Theoretical PDR models help explain the observed correlation of the CO J = 1-0 luminosity with the molecular mass and also suggest FUV-induced feedback mechanisms that may regulate star formation rates and the column density through giant molecular clouds.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.179
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 51
    Digitale Medien
    Digitale Medien
    FAINT BLUE GALAXIES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 389-443 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract The physical properties of the faint blue galaxy population are reviewed in the context of observational progress made via deep spectroscopic surveys and Hubble Space Telescope imaging of field galaxies at various limits and theoretical models for the integrated star formation history of the universe. Notwithstanding uncertainties in the properties of the local population of galaxies, convincing evidence has emerged from several independent studies for a rapid decline in the volume-averaged star-formation rate of field galaxies since a redshift z = 1. Together with the small angular sizes and modest mean redshift of the faintest detectable sources, these results can be understood in hierarchical models where the bulk of the star formation occurred at redshifts between z = 1-2. The physical processes responsible for the subsequent demise of the faint blue galaxy population remain unclear. Considerable progress will be possible when the evolutionary trends can be monitored in the context of independent physical parameters such as the underlying galactic mass.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.389
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 52
    Digitale Medien
    Digitale Medien
    ABUNDANCE RATIOS AND GALACTIC CHEMICAL EVOLUTION (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 503-556 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract The metallicity of stars in the Galaxy ranges from [Fe/H] = -4 to +0.5 dex, and the solar iron abundance is epsilon(Fe) = 7.51 +- 0.01 dex. The average values of [Fe/H] in the solar neighborhood, the halo, and Galactic bulge are -0.2, -1.6, and -0.2 dex respectively. Detailed abundance analysis reveals that the Galactic disk, halo, and bulge exhibit unique abundance patterns of O, Mg, Si, Ca, and Ti and neutron-capture elements. These signatures show that environment plays an important role in chemical evolution and that supernovae come in many flavors with a range of element yields. The 300-fold dispersion in heavy element abundances of the most metal-poor stars suggests incomplete mixing of ejecta from individual supernova, with vastly different yields, in clouds of ~106 M . The composition of Orion association stars indicates that star-forming regions are significantly self-enriched on time scales of 80 million years. The rapid self-enrichment and inhomogeneous chemical evolution models are required to match observed abundance trends and the dispersion in the age-metallicity relation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.503
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 53
    Digitale Medien
    Digitale Medien
    GENOMIC IMPRINTING IN MAMMALS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 493-525 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract A handful of autosomal genes in the mammalian genome are inherited in a silent state from one of the two parents, and in a fully active form from the other, thereby rendering the organism functionally hemizygous for imprinted genes. To date 19 imprinted genes have been identified; 5 are expressed from the maternal chromosome while the rest are expressed from the paternal chromosome. Allele-specific methylation of CpG residues, established in one of the germlines and maintained throughout embryogenesis, has been clearly implicated in the maintenance of imprinting in somatic cells. Although the function of imprinting remains a subject of some debate, the process is thought to have an important role in regulating the rate of fetal growth.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.493
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 54
    Digitale Medien
    Digitale Medien
    X-CHROMOSOME INACTIVATION IN MAMMALS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 571-610 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract The inactive X chromosome differs from the active X in a number of ways; some of these, such as allocyclic replication and altered histone acetylation, are associated with all types of epigenetic silencing, whereas others, such as DNA methylation, are of more restricted use. These features are acquired progressively by the inactive X after onset of initiation. Initiation of X-inactivation is controlled by the X-inactivation center (Xic) and influenced by the X chromosome controlling element (Xce), which causes primary nonrandom X-inactivation. Other examples of nonrandom X-inactivation are also presented in this review. The definition of a major role for Xist, a noncoding RNA, in X-inactivation has enabled investigation of the mechanism leading to establishment of the heterochromatinized X-chromosome and also of the interactions between X-inactivation and imprinting as well as between X-inactivation and developmental processes in the early embryo.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.571
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 55
    Digitale Medien
    Digitale Medien
    ATAXIA-TELANGIECTASIA AND THE NIJMEGEN BREAKAGE SYNDROME:Related Disorders But Genes Apart (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 635-662 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Gene mutations provide valuable clues to cellular metabolism. In humans such insights come mainly from genetic disorders. Ataxia-telangiectasia (A-T) and Nijmegen breakage syndrome (NBS) are two distinct, but closely related, single gene disorders that highlight a complex junction of several signal transduction pathways. These pathways appear to control defense mechanisms against specific types of damage to cellular macromolecules, and probably regulate the processing of certain types of DNA damage or normal intermediates of DNA metabolism. A-T is characterized primarily by cerebellar degeneration, immunodeficiency, genome instability, clinical radiosensitivity, and cancer predisposition. NBS shares all these features except cerebellar deterioration. The cellular phenotypes of A-T and NBS are almost indistinguishable, however, and include chromosomal instability, radiosensitivity, and defects in cell cycle checkpoints normally induced by ionizing radiation. The recent identification of the gene responsible for A-T, ATM, has revealed its product to be a large, constitutively expressed phosphoprotein with a carboxy-terminal region similar to the catalytic domain of phosphatidylinositol 3-kinases (PI 3-kinases). ATM is a member of a family of proteins identified in various organisms, which share the PI 3-kinase domain and are involved in regulation of cell cycle progression and response to genotoxic agents. Some of these proteins, most notably the DNA-dependent protein kinase, have an associated protein kinase activity, and preliminary data indicate this activity in ATM as well. Mutations in A-T patients are null alleles that truncate or destabilize the ATM protein. Atm-deficient mice recapitulate the human phenotype with slower nervous-system degeneration. Two ATM interactors, c-Abl and p53, underscore its role in cellular responses to genotoxic stress. The complexity of ATM's structure and mode of action make it a paradigm of multifaceted signal transduction proteins involved in many physiological pathways via multiple protein-protein interactions. The as yet unknown NBS protein may be a component in an ATM-based complex, with a key role in sensing and processing specific DNA damage or intermediates and signaling their presence to the cell cycle machinery.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.635
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 56
    Digitale Medien
    Digitale Medien
    ANTISENSE RNA-REGULATED PROGRAMMED CELL DEATH (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 1-31 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Eubacterial plasmids and chromosomes encode multiple killer genes belonging to the hok gene family. The plasmid-encoded killer genes mediate plasmid stabilization by killing plasmid-free cells. This review describes the genetics, molecular biology, and evolution of the hok gene family. The complicated antisense RNA-regulated control-loop that regulates posttranscriptional and postsegregational activation of killer mRNA translation in plasmid-free cells is described in detail. Nucleotide covariations in the mRNAs reveal metastable stem-loop structures that are formed at the mRNA 5' ends in the nascent transcripts. The metastable structures prevent translation and antisense RNA binding during transcription. Coupled nucleotide covariations provide evidence for a phylogenetically conserved mRNA folding pathway that involves sequential dynamic RNA rearrangements. Our analyses have elucidated an intricate mechanism by which translation of an antisense RNA-regulated mRNA can be conditionally activated. The complex phylogenetic relationships of the plasmid- and chromosome-encoded systems are also presented and discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.1
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 57
    Digitale Medien
    Digitale Medien
    TRANSPOSABLE ELEMENT-HOST INTERACTIONS:Regulation of Insertion and Excision (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 381-404 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Transposable elements propagate by inserting into new locations in the genomes of the hosts they inhabit. Their transposition might thus negatively affect the fitness of the host, suggesting the requirement for a tight control in the regulation of transposable element mobilization. The nature of this control depends on the structure of the transposable element. DNA elements encode a transposase that is necessary, and in most cases sufficient, for mobilization. In general, regulation of these elements depends on intrinsic factors with little direct input from the host. Retrotransposons require an RNA intermediate for transposition, and their frequency of mobilization is controlled at multiple steps by the host genome by regulating both their expression levels and their insertional specificity. As a result, a symbiotic relationship has developed between transposable elements and their host. Examples are now emerging showing that transposons can contribute significantly to the well being of the organisms they populate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.381
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 58
    Digitale Medien
    Digitale Medien
    ASSEMBLY AND ENLARGEMENT OF THE PRIMARY CELL WALL IN PLANTS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 171-201 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Growing plant cells are shaped by an extensible wall that is a complex amalgam of cellulose microfibrils bonded noncovalently to a matrix of hemicelluloses, pectins, and structural proteins. Cellulose is synthesized by complexes in the plasma membrane and is extruded as a self-assembling microfibril, whereas the matrix polymers are secreted by the Golgi apparatus and become integrated into the wall network by poorly understood mechanisms. The growing wall is under high tensile stress from cell turgor and is able to enlarge by a combination of stress relaxation and polymer creep. A pH-dependent mechanism of wall loosening, known as acid growth, is characteristic of growing walls and is mediated by a group of unusual wall proteins called expansins. Expansins appear to disrupt the noncovalent bonding of matrix hemicelluloses to the microfibril, thereby allowing the wall to yield to the mechanical forces generated by cell turgor. Other wall enzymes, such as (1 4) beta-glucanases and pectinases, may make the wall more responsive to expansin-mediated wall creep, whereas pectin methylesterases and peroxidases may alter the wall so as to make it resistant to expansin-mediated creep.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.171
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 59
    Digitale Medien
    Digitale Medien
    VARIABILITY OF ACTIVE GALACTIC NUCLEI (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 445-502 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract A large collective effort to study the variability of active galactic nuclei (AGN) over the past decade has led to a number of fundamental results on radio-quiet AGN and blazars. In radio-quiet AGN, the ultraviolet (UV) bump in low-luminosity objects is thermal emission from a dense medium, very probably an accretion disk, irradiated by the variable X-ray source. The validity of this model for high-luminosity radio-quiet AGN is unclear because the relevant UV and X-ray observations are lacking. The broad-line gas kinematics appears to be dominated by virialized motions in the gravity field of a black hole, whose mass can be derived from the observed motions. The "accretion disk plus wind" model explains most of the variability (and other) data and appears to be the most appropriate model at present. Future investigations are outlined. In blazars, rapid variability at the highest energies (gamma-rays) implies that the whole continuum is relativistically boosted along the line of sight. The general correlation found between variations in TeV gamma rays and in X rays for Mrk 421, and between variations in GeV gamma rays and in the IR-optical-UV bands for 3C 279, two prototype objects, supports models in which the same population of relativistic electrons radiates the low-frequency continuum via synchrotron and the high frequency continuum via inverse Compton scattering of soft photons. Identifying the dominant source of soft photons, which is at present unclear, will strongly constrain the jet physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.445
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 60
    Digitale Medien
    Digitale Medien
    PARSEC-SCALE JETS IN EXTRAGALACTIC RADIO SOURCES1 (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 607-636 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract Observations of parsec-scale radio jets associated with active galactic nuclei are reviewed, with a particular emphasis on high-luminosity core-dominated sources where the most detailed information on individual objects exists. Extensive imaging surveys with very long baseline interferometry (VLBI) have made possible a morphologic classification of compact radio sources and systematic studies of the statistics of apparent (often faster-than-light) motions found in an increasing number of sources. VLBI monitoring studies at centimeter and millimeter wavelengths, enhanced by spectral and polarization imaging, of representative types of AGN can discriminate detailed physical models. The observations are especially discussed in light of the variant of the relativistic beaming model that explains kinematic, spectral, and polarization properties of parsec-scale jets through shocks in an underlying continuous jet flow.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.607
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 61
    Digitale Medien
    Digitale Medien
    PARABOLIZED STABILITY EQUATIONS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 245-283 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract Parabolized stability equations (PSE) have opened new avenues to the analysis of the streamwise growth of linear and nonlinear disturbances in slowly varying shear flows such as boundary layers, jets, and far wakes. Growth mechanisms include both algebraic transient growth and exponential growth through primary and higher instabilities. In contrast to the eigensolutions of traditional linear stability equations, PSE solutions incorporate inhomogeneous initial and boundary conditions as do numerical solutions of the Navier-Stokes equations, but they can be obtained at modest computational expense. PSE codes have developed into a convenient tool to analyze basic mechanisms in boundary-layer flows. The most important area of application, however, is the use of the PSE approach for transition analysis in aerodynamic design. Together with the adjoint linear problem, PSE methods promise improved design capabilities for laminar flow control systems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.245
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 62
    Digitale Medien
    Digitale Medien
    CONVECTION INTO DOMAINS WITH OPEN BOUNDARIES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 327-371 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract Convection into regions with open, or partially-open, lateral boundaries is considered. The products of convectively-driven mixing can flow out from under the source generating a compensating inflow as they do so. The effects of rotation, ambient stratification and the geometry of the region on these flow quantities are considered, since all affect the density and velocity distributions that result. Three typical geometries are considered: convection into a channel or sea with an exit constriction; convection from a patch or strip into stratified and/or rotating surroundings and, finally, into a rotating coastal environment. In each case the simplest possible models are considered in the hope that they can offer some insight into the dynamical processes that affect the overall behaviour of each system. These are supplemented by reference to numerical and laboratory experiments as well as field observations. Finally suggestions for future work in the former two cases are presented in the hope that they will stimulate the reader's interest.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.327
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 63
    Digitale Medien
    Digitale Medien
    QUANTITATIVE FLOW VISUALIZATION IN UNSEEDED FLOWS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 285-326 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract The various tools for flow visualization have been significantly expanded over the past several years through the use of molecular scattering and molecular laser-induced fluorescence. These approaches have added the capability of sampling individual small volume elements within a flow, and by using cameras for detection, they are easily extended to sample lines and cross-sectional planes. This localized measurement capability means that these approaches can be made quantitative even in complex and/or unsteady flow fields. If the molecular species is naturally occurring, such as oxygen or nitrogen in air, then no seeding is required. Furthermore, in these applications, images of the flow can be frozen in time by using a short pulse laser for illumination. The distribution of the molecules reflects the true physics of the flow, so even raw images taken in this manner give an immediate understanding of flow field properties. With proper calibration, the images can be further analyzed to yield quantitative information about the flow. In the case of flow tagging, the analysis gives velocity profiles when lines are written, and deformation, vorticity, and dilation with grid patterns. Molecular scattering can be used to give quantitative values of density, temperature, and two-dimensional velocity. This paper presents three such molecular-based approaches: laser-induced fluorescence from oxygen, flow tagging by oxygen excitation, and Rayleigh scattering. These three approaches are chosen because all three can be used in naturally occurring air with no seeding. The raw data from each of these approaches gives an immediate appreciation of the flow structure and further analysis yields accurate values of velocity, temperature, and density. These approaches use readily available laser sources; however, they will be greatly enhanced with new source technologies that are currently under development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.285
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 64
    Digitale Medien
    Digitale Medien
    FLUID MECHANICS OF SPIN CASTING OF METALS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 373-397 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract Casting of molten metals against a spinning wheel substrate is considered. Issues of fluid mechanics divide between steady and unsteady behavior (stability). The previous work on steady casting is hung on a framework provided by the long-puddle model of planar flow casting. Heat and fluid flow interact only through the shape of the solidification front in this case. In contrast, there is little previous work concerning stability issues. Stability is discussed in a broad-brush manner using the planar flow process for illustration. Issues range from meniscus motion and resulting ribbon texture to morphological-type instabilities of the solidification front. Fundamental and applied questions arise for both steady and unsteady behavior.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.373
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 65
    Digitale Medien
    Digitale Medien
    BLOOD FLOW IN ARTERIES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 399-434 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract Blood flow in arteries is dominated by unsteady flow phenomena. The cardiovascular system is an internal flow loop with multiple branches in which a complex liquid circulates. A nondimensional frequency parameter, the Womersley number, governs the relationship between the unsteady and viscous forces. Normal arterial flow is laminar with secondary flows generated at curves and branches. The arteries are living organs that can adapt to and change with the varying hemodynamic conditions. In certain circumstances, unusual hemodynamic conditions create an abnormal biological response. Velocity profile skewing can create pockets in which the direction of the wall shear stress oscillates. Atherosclerotic disease tends to be localized in these sites and results in a narrowing of the artery lumen-a stenosis. The stenosis can cause turbulence and reduce flow by means of viscous head losses and flow choking. Very high shear stresses near the throat of the stenosis can activate platelets and thereby induce thrombosis, which can totally block blood flow to the heart or brain. Detection and quantification of stenosis serve as the basis for surgical intervention. In the future, the study of arterial blood flow will lead to the prediction of individual hemodynamic flows in any patient, the development of diagnostic tools to quantify disease, and the design of devices that mimic or alter blood flow. This field is rich with challenging problems in fluid mechanics involving three-dimensional, pulsatile flows at the edge of turbulence.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.399
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 66
    Digitale Medien
    Digitale Medien
    THE PHENOMENOLOGY OF SMALL-SCALE TURBULENCE (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 435-472 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: I have sometimes thought that what makes a man's work classic is often just this multiplicity [of interpretations], which invites and at the same time resists our craving for a clear understanding. Wright (1982, p. 34), on Wittgenstein's philosophy Small-scale turbulence has been an area of especially active research in the recent past, and several useful research directions have been pursued. Here, we selectively review this work. The emphasis is on scaling phenomenology and kinematics of small-scale structure. After providing a brief introduction to the classical notions of universality due to Kolmogorov and others, we survey the existing work on intermittency, refined similarity hypotheses, anomalous scaling exponents, derivative statistics, intermittency models, and the structure and kinematics of small-scale structure-the latter aspect coming largely from the direct numerical simulation of homogeneous turbulence in a periodic box.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.435
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 67
    Digitale Medien
    Digitale Medien
    TEMPORAL PATTERN FORMATION BY HETEROCHRONIC GENES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 611-634 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Heterochrony describes the phylogenetic variation in the relative timing of major developmental events. Such heterochronic variation has been noted across phylogeny, including closely related species, suggesting that particular genetic loci control global aspects of developmental timing, and that variation at those loci may play important roles in evolutionary change. Genetic analyses of heterochronic mutations in the nematode Caenorhabditis elegans reveal that control of temporal patterning is analogous to the dedicated genetic pathways that control the patterning of the spatial axes in Drosophila and other metazoans. These pathways generate graded or binary levels of regulatory factors that pattern particular axes of the developing animal. C. elegans heterochronic genes constitute a regulatory cascade that both generates a temporal decrease in the level of the LIN-14 and LIN-28 proteins and responds to the changes in these gene activities to coordinate the temporal sequence of many cell fates as the animal develops. The temporal regulation of lin-14 and lin-28 gene activities is posttranscriptional and mediated by the antisense RNA product of the lin-4 gene. Hormonal control of developmental timing is a common theme throughout phylogeny. Heterochronic genes that involve hormonal signaling have been identified in vertebrates as well as C. elegans.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.611
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 68
    Digitale Medien
    Digitale Medien
    MODERN THOUGHTS ON AN ANCYENT MARINERE:Function, Evolution, Regulation (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 337-358 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract The mariner/Tc1 superfamily of transposable elements is one of the most diverse and widespread Class II transposable elements. Within the larger assemblage, the mariner-like elements (MLEs) and the Tc1-like elements (TLEs) are distinct families differing characteristically in the composition of the "D,D(35)E" cation-binding domain. Based on levels of sequence similarity, the elements in each family can be subdivided further into several smaller subfamilies. MLEs and TLEs both have an extraordinarily wide host range. They are abundant in insect genomes and other invertebrates and are found even in some vertebrate species including, in the case of mariner, humans, in which one element on chromosome 17p has been implicated as a hotspot of recombination. In spite of the extraordinary evolutionary success of the elements, virtually nothing is known about their mode of regulation within genomes. There is abundant evidence that the elements are disseminated to naive host genomes by horizontal transmission, and there is a substantial base of evidence for inference about the subsequent population dynamics. Studies of engineered mariner elements and induced mutations in the transposase have identified two mechanisms that may be operative in mariner regulation. One mechanism is overproduction inhibition, in which excessive wild-type transposase reduces the rate of excision of a target element. A second mechanism is dominant-negative complementation, in which certain mutant transposase proteins antagonize the activity of the wild-type transposase. The latter process may help explain why the vast majority of MLEs in nature undergo "vertical inactivation" by multiple mutations and, eventually, stochastic loss. There is also evidence that mariner/Tc1 elements can be mobilized in hybrid dysgenesis; in particular, certain dysgenic crosses in Drosophila virilis result in mobilization of a TLE designated Paris as well as the mobilization of other unrelated transposable elements.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.337
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 69
    Digitale Medien
    Digitale Medien
    THE GENETIC PROGRAM FOR GERM-SOMA DIFFERENTIATION IN VOLVOX (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 359-380 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Volvox carteri possesses only two cell types: mortal somatic cells and potentially immortal asexual reproductive cells called gonidia. Mutational analysis indicates that three categories of genes play central roles in programming this germ-soma division of labor: First the gls genes function during embryogenesis to cause asymmetric divisions that produce large and small cells. Then the lag genes act in the large cells (gonidial initials) to repress functions required for somatic development while the regA locus acts in the small cells (somatic initials) to repress functions required for reproductive development. Transposon tagging and DNA transformation have recently been used to recover and characterize the glsA and regA genes, and the sequences of these genes lead to testable hypotheses about how they play their roles in germ-soma differentiation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.359
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 70
    Digitale Medien
    Digitale Medien
    GERMLINE CYST FORMATION IN DROSOPHILA (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 405-428 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract In a wide variety of organisms, gametes develop within clusters of interconnected germline cells called cysts. Four major principles guide the construction of most cysts: synchronous division, a maximally branched pattern of interconnection between cells, specific changes in cyst geometry, and cyst polarization. The fusome is a germline-specific organelle that is associated with cyst formation in many insects and is likely to play an essential role in these processes. This review examines the cellular and molecular processes that underlie fusome formation and cyst initiation, construction, and polarization in Drosophila melanogaster. The studies described here highlight the importance of cyst formation to the subsequent development of functional gametes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.405
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 71
    Digitale Medien
    Digitale Medien
    CONSEQUENCES OF CHROMOSOMAL ABNORMALITIES IN TUMOR DEVELOPMENT (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 429-453 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract This article highlights recent advances in the molecular structure and function of proteins that are activated or created by chromosomal abnormalities and discusses their possible role in tumor development. The molecular characterization of these proteins has revealed that tumor-specific fusion proteins are the consequence of most chromosome translocations associated with leukemias and solid tumors. An emerging common theme is that creation of these proteins disrupts the normal development of tumor-specific target cells by blocking apoptosis. These insights identify these chromosomal translocation-associated genes as potential targets for improved cancer therapies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.429
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 72
    Digitale Medien
    Digitale Medien
    UNDERSTANDING GENE AND ALLELE FUNCTION WITH TWO-HYBRID METHODS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 663-704 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Two-hybrid schemes for detecting protein-protein interactions have deepened our understanding of biology by allowing scientists to identify individual important proteins. Recent developments will allow biologists to chart regulatory networks and to rapidly generate hypotheses for the function of genes, allelic variants, and the connections between proteins that make up these networks. Future developments will allow biologists to test inferences about the function of network elements, and allow global approaches to questions of biological function.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.663
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 73
    Digitale Medien
    Digitale Medien
    CYCLIN-DEPENDENT KINASES: Engines, Clocks, and Microprocessors (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 261-291 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Cyclin-dependent kinases (Cdks) play a well-established role in the regulation of the eukaryotic cell division cycle and have also been implicated in the control of gene transcription and other processes. Cdk activity is governed by a complex network of regulatory subunits and phosphorylation events whose precise effects on Cdk conformation have been revealed by recent crystallographic studies. In the cell, these regulatory mechanisms generate an interlinked series of Cdk oscillators that trigger the events of cell division.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.261
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 74
    Digitale Medien
    Digitale Medien
    INITIATION OF DNA REPLICATION IN EUKARYOTIC CELLS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 293-332 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract The recent identification of proteins that recognize origins of DNA replication and control the initiation of eukaryotic DNA replication has provided critical molecular tools to dissect this process. Dynamic changes in the assembly and disassembly of protein complexes at origins are important for the initiation of DNA replication and occur throughout the cell cycle. Herein, we review the key proteins required for the initiation of DNA replication, their involvement in the protein complex assembly at replication origins, and how the cell cycle machinery regulates this process.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.293
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 75
    Digitale Medien
    Digitale Medien
    NUCLEAR ASSEMBLY (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 669-695 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract We review old and new insights into the structure of the nuclear envelope and the components responsible for its dynamic reassembly during mitosis. New information is coming to light about several of the proteins that mediate nuclear reassembly. These proteins include the lamins and their emerging relationship with proteins such as otefin and the MAN antigens: peripheral proteins that might participate in lamina structure. There are four identified proteins localized to the inner nuclear membrane: the lamina-associated proteins LAP1 and LAP2, emerin, and the lamin B receptor (LBR). LBR can interact independently with lamin B and a chromodomain protein, Hp1, and appears to be a central player in targeting nuclear membranes to chromatin. Intermediates in the assembly of nuclear pore complexes (NPCs) can now be studied biochemically and visualized by high resolution scanning electron microscopy. We discuss the possibility that the filament-forming proteins Tpr/p270, NuMA, and perhaps actin may have roles in nuclear assembly.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.669
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 76
    Digitale Medien
    Digitale Medien
    PLANT CELL MORPHOGENESIS: Plasma Membrane Interactions with the Cytoskeleton and Cell Wall (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 697-743 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract Because plants are composed of immobile cells, plant morphogenesis requires mechanisms allowing precise control of cell expansion and cell division patterns. Cortical domains, localized in response to directional cues, are of central importance in establishing cell polarity, orienting cell division, and determining daughter cell fates in a wide variety of prokaryotic and eukaryotic organisms. Such domains consist of localized macromolecular complexes that, in plant cells, provide spatial control of cell expansion and cell division functions. The role of the cytoskeleton, plasma membrane, and targeted secretion to the cell wall in the spatial regulation of cell morphogenesis in plants is discussed in light of recent results from model organisms, including brown algal zygotes (e.g. Fucus). A general model, emphasizing the importance of cortical sites and targeted secretion, is proposed for morphogenesis in higher plant cells based on current knowledge and principles derived from analysis of the establishment of a stable cortical asymmetry in Fucus. The model illustrates mechanisms to direct the orientation of an asymmetric division resulting in daughter cells with different fates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.697
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 77
    Digitale Medien
    Digitale Medien
    STRUCTURE, FUNCTION AND REGULATION OF THE VACUOLAR (H+)-ATPase (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 779-808 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract The vacuolar (H+)-ATPases (or V-ATPases) function in the acidification of intracellular compartments in eukaryotic cells. The V-ATPases are multisubunit complexes composed of two functional domains. The peripheral V1 domain, a 500-kDa complex responsible for ATP hydrolysis, contains at least eight different subunits of molecular weight 70-13 (subunits A-H). The integral V0 domain, a 250-kDa complex, functions in proton translocation and contains at least five different subunits of molecular weight 100-17 (subunits a-d). Biochemical and genetic analysis has been used to identify subunits and residues involved in nucleotide binding and hydrolysis, proton translocation, and coupling of these activities. Several mechanisms have been implicated in the regulation of vacuolar acidification in vivo, including control of pump density, regulation of assembly of V1 and V0 domains, disulfide bond formation, activator or inhibitor proteins, and regulation of counterion conductance. Recent information concerning targeting and regulation of V-ATPases has also been obtained.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.779
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 78
    Digitale Medien
    Digitale Medien
    THE DESIGN PLAN OF KINESIN MOTORS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Cell and Developmental Biology 13 (1997), S. 745-777 
    Details
    ISSN: 1081-0706
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie , Medizin
    Notizen: Abstract The kinesin superfamily comprises a large and structurally diverse group of microtubule-based motor proteins that produce a variety of force-generating activities within cells. This review addresses how the structures of kinesin proteins provide clues as to their biological functions and motile properties. We discuss structural features common to all kinesin motors, as well as specialized features that enable subfamilies of related motors to carry out specialized activities. We also discuss how the kinesin motor domain uses chemical energy from ATP hydrolysis to move along microtubules.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.cellbio.13.1.745
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 79
    Digitale Medien
    Digitale Medien
    LUMINOUS SUPERSOFT X-RAY SOURCES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 69-100 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract Luminous supersoft X-ray sources were discovered with the Einstein observatory and have been established as an important new class of X-ray binaries on the basis of observations with the Roentgen Satellite (ROSAT). They have extremely soft spectra (equivalent blackbody temperatures of ~15-80 eV) and are highly luminous (bolometric luminosities of 1036-1038 erg s-1). Correcting for the heavy extinction of soft X rays by interstellar neutral hydrogen, their numbers in the disks of ordinary spiral galaxies like our own and M31 are estimated to be of the order of 103. Their observed characteristics are consistent with those of white dwarfs, which are steadily or cyclically burning hydrogen-rich matter accreted onto the surface at a rate of order 10-7 year-1. The required high accretion rates can be supplied by mass transfer on a thermal time scale (106-107 years) from close companion stars that are more massive than the white dwarf accretor, typically 1.3-2.5 . Steady burning can also occur in a post-nova stage, but for shorter time scales, and it has been observed in a few classical novae and symbiotic novae. A few supersoft sources have been found to be recurrent transients. They are possibly connected with very massive white dwarfs accreting at high rates. Luminous supersoft sources may make a considerable contribution to the Type Ia supernova rate in spiral and irregular galaxies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.69
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 80
    Digitale Medien
    Digitale Medien
    OBSERVATIONAL SELECTION BIAS AFFECTING THE DETERMINATION OF THE EXTRAGALACTIC DISTANCE SCALE (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 101-136 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract The influence of Malmquist bias on the studies of extragalactic distances is reviewed, with brief glimpses of the history from Kapteyn to Scott. Special attention is paid to two kinds of biases, for which the names Malmquist biases of the first and second kind are proposed. The essence of these biases and the situations where they occur are discussed. The bias of the first kind is related to the classical Malmquist bias (involving the "volume effect"), while the bias of the second kind appears when standard candles are observed at different (true) distances, whereby magnitude limit cuts away a part of the luminosity function. In particular, study of the latter bias in distance indicators such as Tully Fisher, available for large fundamental samples of galaxies, allows construction of an unbiased absolute distance scale in the local galaxy universe where approximate kinematic relative distances can be derived. Such investigations, using the method of normalized distances or of the Spaenhauer diagram, support the linearity of the Hubble law and make it possible to derive an unbiased value of the Hubble constant.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.101
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 81
    Digitale Medien
    Digitale Medien
    HIGH-VELOCITY CLOUDS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 217-266 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract High-velocity clouds (HVCs) consist of neutral hydrogen (HI) at velocities incompatible with a simple model of differential galactic rotation; in practice one uses vLSR 90 km/s to define HVCs. This review describes the main features of the sky and velocity distributions, as well as the available information on cloud properties, small-scale structure, velocity structure, and observations other than in 21-cm emission. We show that HVCs contain heavy elements and that the more prominent ones are more than 2 kpc from the Galactic plane. We evaluate the hypotheses proposed for their origin and reject those that account for only one or a few HVCs. At least three different hypotheses are needed: one for the Magellanic Stream and possibly related clouds, one for the Outer Arm Extension, and one (or more) for the other HVCs. We discuss the evidence for the accretion and the fountain model but cannot rule out either one.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.217
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 82
    Digitale Medien
    Digitale Medien
    OPTICAL SPECTRA OF SUPERNOVAE (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 309-355 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract The temporal evolution of the optical spectra of various types of supernovae (SNe) is illustrated, in part to aid observers classifying supernova candidates. Type II SNe are defined by the presence of hydrogen, and they exhibit a very wide variety of photometric and spectroscopic properties. Among hydrogen-deficient SNe (Type I), three subclasses are now known: those whose early-time spectra show strong Si II (Ia), prominent He I (Ib), or neither Si II nor He I (Ic). The late-time spectra of SNe Ia consist of a multitude of blended emission lines of iron-group elements; in sharp contrast, those of SNe Ib and SNe Ic (which are similar to each other) are dominated by several relatively unblended lines of intermediate-mass elements. Although SNe Ia, which result from the thermonuclear runaway of white dwarfs, constitute a rather homogeneous subclass, important variations in their photometric and spectroscopic properties are undeniably present. SNe Ib/Ic probably result from core collapse in massive stars largely stripped of their hydrogen (Ib) and helium (Ic) envelopes, and hence they are physically related to SNe II. Indeed, the progenitors of some SNe II seem to have only a low-mass skin of hydrogen; their spectra gradually evolve to resemble those of SNe Ib. In addition to the two well-known photometric subclasses (linear and plateau) of SNe II, which may exhibit minor spectroscopic differences, there is a new subclass (SNe IIn) distinguished by relatively narrow emission lines with little or no P Cygni absorption component and slowly declining light curves. These objects probably have unusually dense circumstellar gas with which the ejecta interact.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.309
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 83
    Digitale Medien
    Digitale Medien
    GALACTIC BULGES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Astronomy and Astrophysics 35 (1997), S. 637-675 
    Details
    ISSN: 0066-4146
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Physik
    Notizen: Abstract We discuss the present observational and theoretical understanding of the stellar populations of bulges and their implications for galaxy formation and evolution. The place of bulges as key to the Hubble Sequence remains secure, but some old paradigms are giving way to new ones as observations develop. Detailed studies of Local Group bulges and haloes provide a basis on which we consider higher redshift data. We present the evidence for and against the currently common preconceptions that bulges are old, above solar metallicity in the mean, and simply scaled-down versions of ellipticals. We conclude life is not so simple: Bulges are diverse and heterogeneous, and although their properties vary systematically, sometimes they are reminiscent of disks, sometimes of ellipticals. The extant observational data are, however, limited. New and future surveys will rectify this, and we discuss the questions those data will address.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.astro.35.1.637
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 84
    Digitale Medien
    Digitale Medien
    G. I. TAYLOR IN HIS LATER YEARS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 1-25 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.1
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 85
    Digitale Medien
    Digitale Medien
    ELECTROHYDRODYNAMICS:The Taylor-Melcher Leaky Dielectric Model (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 27-64 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract Electrohydrodynamics deals with fluid motion induced by electric fields. In the mid 1960s GI Taylor introduced the leaky dielectric model to explain the behavior of droplets deformed by a steady field, and JR Melcher used it extensively to develop electrohydrodynamics. This review deals with the foundations of the leaky dielectric model and experimental tests designed to probe its usefulness. Although the early experimental studies supported the qualitative features of the model, quantitative agreement was poor. Recent studies are in better agreement with the theory. Even though the model was originally intended to deal with sharp interfaces, contemporary studies with suspensions also agree with the theory. Clearly the leaky dielectric model is more general than originally envisioned.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.27
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 86
    Digitale Medien
    Digitale Medien
    CORE-ANNULAR FLOWS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 65-90 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract This paper gives an overview of the issues posed by the science and technology of transporting heavy oils in a sheath of lubricating water. It touches on measures of energy efficiency, industrial experience, fouling, stability, models of levitation, and future directions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.65
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 87
    Digitale Medien
    Digitale Medien
    UNSTRUCTURED GRID TECHNIQUES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 473-514 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract An overview of the current state of the art in unstructured mesh techniques for computational fluid dynamics is given. The topics of mesh generation and adaptation, spatial discretization, and solution techniques for steady flows are covered. Remaining difficulties in these areas are highlighted, and directions for future work are outlined.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.473
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 88
    Digitale Medien
    Digitale Medien
    CONVECTION IN MUSHY LAYERS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 91-122 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract As a molten alloy or any multi-component liquid is cooled and solidified the growing solid phase usually forms a porous matrix through which the residual liquid can flow. The reactive two-phase medium comprising the solid matrix and residual liquid is called a mushy layer. Buoyancy forces, owing primarily to compositional depletion as one or more of the components of the alloy are extracted to form the solid phase, can drive convection in the layer. In this review, I present an account of various studies of buoyancy-driven convection in mushy layers, paying particular attention to the complex interactions between solidification and flow that lead to novel styles of convective behavior, including focusing of the flow to produce chimneys: narrow, vertical channels devoid of solid. I define an 'ideal' mushy layer and argue that chimneys are an inevitable consequence of convection in ideal mushy layers. The absence of chimneys in certain laboratory experiments is explained in terms of nonideal effects.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.91
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 89
    Digitale Medien
    Digitale Medien
    COMPUTING AERODYNAMICALLY GENERATED NOISE (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 161-199 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract In contrast to computational aerodynamics, which has advanced to a fairly mature state, computational aeroacoustics (CAA) has only recently emerged as a separate area of study. Following a discussion of the classical field of aeroacoustics as introduced by Lighthill, the paper provides an overview and analysis of the problems associated with utilizing standard computational aerodynamics procedures for acoustic computations. Numerical aspects of computing sound-wave propagation are considered, including assessments of several schemes for spatial and temporal differencing. Issues of particular concern in computing aerodynamically generated noise, such as implementing surface and radiation boundary conditions and algorithms for predicting nonlinear steepening and shocks, are discussed. In addition, the paper briefly reviews alternatives to the conventional finite-difference schemes, such as boundary-element and spectral methods and the uncommon lattice-gas method.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.161
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 90
    Digitale Medien
    Digitale Medien
    NONLINEAR BUBBLE DYNAMICS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 201-243 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract The inertia-dominated dynamics of a single gas or vapor bubble in an incompressible or nearly incompressible liquid has been the subject of intense investigation for many years. Studies prior to 1976 were thoroughly reviewed by Plesset & Prosperetti (1977) in Volume 9 of this series. Our review fills the gap between Plesset & Prosperetti's review and the present. We focus on new understandings of bubble dynamics through a nonlinear dynamical systems approach.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.201
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 91
    Digitale Medien
    Digitale Medien
    QUANTIFICATION OF UNCERTAINTY IN COMPUTATIONAL FLUID DYNAMICS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Fluid Mechanics 29 (1997), S. 123-160 
    Details
    ISSN: 0066-4189
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Maschinenbau , Physik
    Notizen: Abstract This review covers Verification, Validation, Confirmation and related subjects for computational fluid dynamics (CFD), including error taxonomies, error estimation and banding, convergence rates, surrogate estimators, nonlinear dynamics, and error estimation for grid adaptation vs Quantification of Uncertainty.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.fluid.29.1.123
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 92
    Digitale Medien
    Digitale Medien
    THE TAO OF STEM CELLS IN THE GERMLINE (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 455-491 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Germline stem cells (GSCs) are the self-renewing population of germ cells that serve as the source for gametogenesis. GSCs exist in diverse forms, from those that undergo strict self-renewing asymmetric divisions in Drosophila to those that maintain their population by balancing between mitosis and differentiation in Caenorhabditis elegans. Most vertebrate spermatogonial GSCs appear to adopt an intermediate strategy. In most animals, GSCs are established during preadult gonadogenesis following the proliferation and migration of embryonic primordial germ cells. GSCs produce numerous gametes throughout the sexually active period of adult life. The establishment and self-renewing division of GSCs are controlled by extracellular signals such as hormones from the hypothalamic-pituitary axis and local interactions between GSCs and their neighboring cells. These extracellular signals may then influence differential gene expression, cell cycle machinery, and cytoskeletal organization of GSCs for their formation and/or divisional asymmetry. In addition, the GSC mechanism is related to that for germline and sex determination. Current knowledge has provided a solid framework for further study of GSCs and stem cells in general.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.455
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 93
    Digitale Medien
    Digitale Medien
    USE OF ARABIDOPSIS FOR GENETIC DISSECTION OF PLANT DEFENSE RESPONSES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 547-569 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Arabidopsis thaliana (Arabidopsis) is proving to be an ideal model system for studies of host defense responses to pathogen attack. The Arabidopsis genetic system is significantly more tractable than those of other plant species, and Arabidopsis exhibits all of the major kinds of defense responses described in other plants. A large number of virulent and avirulent bacterial, fungal, and viral pathogens of Arabidopsis have been collected. In the last few years, a large number of mutations have been identified in Arabidopsis that cause a wide variety of specific defense-related phenotypes. Analysis of these mutant phenotypes is beginning to give glimpses into the complex signal transduction pathways leading to the induction of the defense responses involved in protecting plants from pathogen infection.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.547
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 94
    Digitale Medien
    Digitale Medien
    HOST-PATHOGEN INTERACTIONS DURING ENTRY AND ACTIN-BASED MOVEMENT OF LISTERIA MONOCYTOGENES (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 113-138 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Listeria monocytogenes is a pathogenic bacterium that induces its own uptake into mammalian cells, and spreads from one cell to another by an actin-based motility process. Entry into host cells involves the bacterial surface proteins InlA (internalin) and InlB. The receptor for InlA is the cell adhesion molecule E-cadherin. InlB-mediated entry requires activation of the host protein phosphoinositide (PI) 3-kinase, probably in response to engagement of a receptor. Actin-based movement of L. monocytogenes is mediated by the bacterial surface protein ActA. The N-terminal region of this protein is necessary and sufficient for polymerization of host cell actin. Other host proteins involved in bacterial motility include profilin, Vasodilator-Stimulated Phosphoprotein (VASP), the Arp2/Arp3 complex, and cofilin. Studies of entry and intracellular movement of L. monocytogenes could lead to a better understanding of receptor-ligand signaling and dynamics of actin polymerization in mammalian cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.113
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 95
    Digitale Medien
    Digitale Medien
    GENETICS OF PRIONS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 139-175 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Prions are unprecedented infectious pathogens that cause a group of invariably fatal, neurodegenerative diseases by an entirely novel mechanism. Prion diseases may present as genetic, infectious, or sporadic disorders, all of which involve modification of the prion protein (PrP). The human prion disease Creutzfeldt-Jakob disease (CJD) generally presents as a progressive dementia, whereas scrapie of sheep and bovine spongiform encephalopathy (BSE) are manifest as ataxic illnesses. Prions are devoid of nucleic acid and seem to be composed exclusively of a modified isoform of PrP designated PrPSc. The normal, cellular PrP designated PrPC is converted into PrPSc through a process whereby some of its alpha-helical structure is converted into beta-sheet. The species of a particular prion is encoded by the sequence of the chromosomal PrP gene of the mammals in which it last replicated. In contrast to pathogens with a nucleic acid genome, prions encipher strain-specific properties in the tertiary structure of PrPSc. Transgenetic studies argue that PrPSc acts as a template upon which PrPC is refolded into a nascent PrPSc molecule through a process facilitated by another protein.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.139
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 96
    Digitale Medien
    Digitale Medien
    VIRAL TRANSACTIVATING PROTEINS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 177-212 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Many viruses utilize the cellular transcription apparatus to express their genomes, and they encode transcriptional regulatory proteins that modulate the process. Here we review the current understanding of three viral regulatory proteins. The adenovirus E1A protein acts within the nucleus to regulate transcription through its ability to bind to other proteins. The herpes simplex type 1 virus VP16 protein acts within the nucleus to control transcription by binding to DNA in conjunction with cellular proteins. The human T-cell leukemia virus Tax protein influences transcription through interactions with cellular proteins in the nucleus as well as the cytoplasm.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.177
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 97
    Digitale Medien
    Digitale Medien
    PROCESSING OF RECOMBINATION INTERMEDIATES BY THE RuvABC PROTEINS (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 213-244 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract The RuvA, RuvB, and RuvC proteins in Escherichia coli play important roles in the late stages of homologous genetic recombination and the recombinational repair of damaged DNA. Two proteins, RuvA and RuvB, form a complex that promotes ATP-dependent branch migration of Holliday junctions, a process that is important for the formation of heteroduplex DNA. Individual roles for each protein have been defined, with RuvA acting as a specificity factor that targets RuvB, the branch migration motor, to the junction. Structural studies indicate that two RuvA tetramers sandwich the junction and hold it in an unfolded square-planar configuration. Hexameric rings of RuvB face each other across the junction and promote a novel dual helicase action that "pumps" DNA through the RuvAB complex, using the free energy provided by ATP hydrolysis. The third protein, RuvC endonuclease, resolves the Holliday junction by introducing nicks into two DNA strands. Genetic and biochemical studies indicate that branch migration and resolution are coupled by direct interactions between the three proteins, possibly by the formation of a RuvABC complex.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.213
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 98
    Digitale Medien
    Digitale Medien
    YEAST GENETICS TO DISSECT THE NUCLEAR PORE COMPLEX AND NUCLEOCYTOPLASMIC TRAFFICKING (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 277-313 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Eukaryotic cells evolved when their genetic information was packed into the cell nucleus. DNA replication and RNA biogenesis occur inside the nucleus while protein synthesis takes place in the cytoplasm. Bi-directional trafficking between these two compartments is mediated by a single supramolecular assembly, the nuclear pore complex. Nucleocytoplasmic transport is signal mediated, energy dependent, and requires, besides nuclear pore proteins (nucleoporins), a number of soluble transport factors. We review here our current knowledge on the role of nucleoporins, and on the mechanism of nucleocytoplasmic transport, with emphasis on the yeast Saccharomyces cerevisiae.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.277
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 99
    Digitale Medien
    Digitale Medien
    MOLECULAR GENETIC BASIS OF ADAPTIVE SELECTION:Examples From Color Vision in Vertebrates (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 315-336 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract A central unanswered question in phototransduction is how photosensitive molecules, visual pigments, regulate their absorption spectra. In nature, there exist various types of visual pigments that are adapted to diverse photic environments. To elucidate the molecular mechanisms involved in the adaptive selection of these pigments, we have to identify amino acid changes of pigments that are potentially important in changing the wavelength of maximal absorption (lambamax) and then determine the effects of these mutations on the shift in lambamax. The desired mutants can be constructed using site-directed mutagenesis, expressed in tissue culture cells, and the functional effect of virtually any such mutant can be rigorously determined. The availability of these cell/molecular methods makes vision an ideal model system in studying adaptive mechanisms at the molecular level. The identification of potentially important amino acid changes using evolutionary biological means is an indispensable step in elucidating the molecular mechanisms that underlie the spectral tuning of visual pigments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.315
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 100
    Digitale Medien
    Digitale Medien
    MATING TYPE IN FILAMENTOUS FUNGI (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 31 (1997), S. 245-276 
    Details
    ISSN: 0066-4197
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Biologie
    Notizen: Abstract Mating type genes regulate sexual compatibility and sexual reproduction in fungi. This review focuses on recent molecular analyses of well-characterized mating systems from representative ascomycete (Neurospora crassa, Podospora anserina) and basidiomycete (Ustilago maydis, Coprinus cinereus, Schizophyllum commune) fungi. These mating systems include many conserved components, such as gene regulatory polypeptides and pheromone/receptor signal transduction cascades, as well as conserved processes, like self-nonself recognition and controlled nuclear migration. The components' structures and their genetic arrangements in the mating system vary greatly in different fungi. Although similar components and processes are also found in ascomycete yeasts (Saccharomyces cerevisiae and Schizosaccharomyces pombe), the filamentous systems exhibit properties not encountered in yeast. Mating type genes act within, and control the development of, spatially differentiated fruiting bodies. The complex mating systems of basidiomycetes, unlike ascomycete systems, involve novel one-to-many specificity in both pheromone-receptor and homeodomain protein interactions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.genet.31.1.245
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...