ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Geophysics  (138)
  • Life Sciences (General)  (5)
  • METEOROLOGY AND CLIMATOLOGY
  • Models, Molecular
  • ddc:330
  • 1995-1999  (146)
  • 1
    facet.materialart.
    Unknown
    A mechanism of drug action revealed by structural studies of enoyl reductase (1996)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1996-12-20
    Description: Enoyl reductase (ENR), an enzyme involved in fatty acid biosynthesis, is the target for antibacterial diazaborines and the front-line antituberculosis drug isoniazid. Analysis of the structures of complexes of Escherichia coli ENR with nicotinamide adenine dinucleotide and either thienodiazaborine or benzodiazaborine revealed the formation of a covalent bond between the 2' hydroxyl of the nicotinamide ribose and a boron atom in the drugs to generate a tight, noncovalently bound bisubstrate analog. This analysis has implications for the structure-based design of inhibitors of ENR, and similarities to other oxidoreductases suggest that mimicking this molecular linkage may have generic applications in other areas of medicinal chemistry.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Baldock, C -- Rafferty, J B -- Sedelnikova, S E -- Baker, P J -- Stuitje, A R -- Slabas, A R -- Hawkes, T R -- Rice, D W -- New York, N.Y. -- Science. 1996 Dec 20;274(5295):2107-10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK. D.Rice@sheffield.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8953047" target="_blank"〉PubMed〈/a〉
    Keywords: Anti-Bacterial Agents/*metabolism/pharmacology ; Binding Sites ; Boron Compounds/*metabolism/pharmacology ; Crystallography, X-Ray ; Drug Design ; Drug Resistance, Microbial ; Enoyl-(Acyl-Carrier-Protein) Reductase (NADH) ; Enzyme Inhibitors/*metabolism/pharmacology ; Escherichia coli/enzymology ; Escherichia coli Proteins ; Fatty Acid Synthase, Type II ; Fatty Acid Synthases/antagonists & inhibitors/*chemistry/metabolism ; Hydrogen Bonding ; Models, Molecular ; NAD/*metabolism ; Oxidoreductases/antagonists & inhibitors/*chemistry/metabolism ; Protein Conformation ; Protein Structure, Secondary
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    Crystal structure of DNA recombination protein RuvA and a model for its binding to the Holliday junction (1996)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1996-10-18
    Description: The Escherichia coli DNA binding protein RuvA acts in concert with the helicase RuvB to drive branch migration of Holliday intermediates during recombination and DNA repair. The atomic structure of RuvA was determined at a resolution of 1.9 angstroms. Four monomers of RuvA are related by fourfold symmetry in a manner reminiscent of a four-petaled flower. The four DNA duplex arms of a Holliday junction can be modeled in a square planar configuration and docked into grooves on the concave surface of the protein around a central pin that may facilitate strand separation during the migration reaction. The model presented reveals how a RuvAB-junction complex may also accommodate the resolvase RuvC.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Rafferty, J B -- Sedelnikova, S E -- Hargreaves, D -- Artymiuk, P J -- Baker, P J -- Sharples, G J -- Mahdi, A A -- Lloyd, R G -- Rice, D W -- Wellcome Trust/United Kingdom -- New York, N.Y. -- Science. 1996 Oct 18;274(5286):415-21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, UK. d.rice@sheffield.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8832889" target="_blank"〉PubMed〈/a〉
    Keywords: Bacterial Proteins/*chemistry/metabolism ; Base Composition ; Crystallography, X-Ray ; DNA Helicases/metabolism ; DNA, Bacterial/chemistry/*metabolism ; DNA-Binding Proteins/*chemistry/metabolism ; Endodeoxyribonucleases/metabolism ; Escherichia coli ; *Escherichia coli Proteins ; Hydrogen Bonding ; Models, Molecular ; *Nucleic Acid Conformation ; Oligodeoxyribonucleotides/chemistry/metabolism ; *Protein Conformation ; Protein Structure, Secondary ; Protein Structure, Tertiary ; *Recombination, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unknown
    Melatonin and cortisol assessment of circadian shifts in astronauts before flight (1995)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: Melatonin and cortisol were measured in saliva and urine samples to assess the effectiveness of a 7-day protocol combining bright-light exposure with sleep shifting in eliciting a 12-hr phase-shift delay in eight U.S. Space Shuttle astronauts before launch. Baseline acrophases for 15 control subjects with normal sleep-wake cycles were as follows: cortisol (saliva) at 0700 (0730 in urine); melatonin (saliva) at 0130 (6-hydroxymelatonin sulfate at 0230 in urine). Acrophases of the astronaut group fell within 2.5 hr of these values before the treatment protocols were begun. During the bright-light and sleep-shifting treatments, both absolute melatonin production and melatonin rhythmicity were diminished during the first 3 treatment days; total daily cortisol levels remained constant throughout the treatment. By the fourth to sixth day of the 7-day protocol, seven of the eight crew members showed phase delays in all four measures that fell within 2 hr of the expected 11- to 12-hr shift. Although cortisol and melatonin rhythms each corresponded with the phase shift, the rhythms in these two hormones did not correspond with each other during the transition.
    Keywords: Life Sciences (General)
    Type: Journal of pineal research (ISSN 0742-3098); Volume 18; 3; 141-7
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Lidar-measured winds from space: A key component for weather and climate prediction (1995)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: The deployment of a space-based Doppler lidar would provide information that is fundamental to advancing the understanding and prediction of weather and climate. This paper reviews the concepts of wind measurement by Doppler lidar, highlights the results of some observing system simulation experiments with lidar winds, and discusses the important advances in earth system science anticipated with lidar winds. Observing system simulation experiments, conducted using two different general circulation models, have shown (1) that there is a significant improvement in the forecast accuracy over the Southern Hemisphere and tropical oceans resulting from the assimilation of simulated satellite wind data, and (2) that wind data are significantly more effective than temperature or moisture data in controlling analysis error. Because accurate wind observations are currently almost entirely unavailable for the vast majority of tropical cyclones worldwide, lidar winds have the potential to substan- tially improve tropical cyclone forecasts. Similarly, to improve water vapor flux divergence calculations, a direct measure of the ageostrophic wind is needed since the present level of uncer- tainty cannot be reduced with better temperature and moisture soundings alone.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: American Meteorological Society, Bulletin (ISSN 0003-0007); 76; 6; p. 869-888
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Changes in gravity inhibit lymphocyte locomotion through type I collagen (1997)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: Immunity relies on the circulation of lymphocytes through many different tissues including blood vessels, lymphatic channels, and lymphoid organs. The ability of lymphocytes to traverse the interstitium in both nonlymphoid and lymphoid tissues can be determined in vitro by assaying their capacity to locomote through Type I collagen. In an attempt to characterize potential causes of microgravity-induced immunosuppression, we investigated the effects of simulated microgravity on human lymphocyte function in vitro using a specialized rotating-wall vessel culture system developed at the Johnson Space Center. This very low shear culture system randomizes gravitational vectors and provides an in vitro approximation of microgravity. In the randomized gravity of the rotating-wall vessel culture system, peripheral blood lymphocytes did not locomote through Type I collagen, whereas static cultures supported normal movement. Although cells remained viable during the entire culture period, peripheral blood lymphocytes transferred to unit gravity (static culture) after 6 h in the rotating-wall vessel culture system were slow to recover and locomote into collagen matrix. After 72 h in the rotating-wall vessel culture system and an additional 72 h in static culture, peripheral blood lymphocytes did not recover their ability to locomote. Loss of locomotory activity in rotating-wall vessel cultures appears to be related to changes in the activation state of the lymphocytes and the expression of adhesion molecules. Culture in the rotating-wall vessel system blunted the ability of peripheral blood lymphocytes to respond to polyclonal activation with phytohemagglutinin. Locomotory response remained intact when peripheral blood lymphocytes were activated by anti-CD3 antibody and interleukin-2 prior to introduction into the rotating-wall vessel culture system. Thus, in addition to the systemic stress factors that may affect immunity, isolated lymphocytes respond to gravitational changes by ceasing locomotion through model interstitium. These in vitro investigations suggest that microgravity induces non-stress-related changes in cell function that may be critical to immunity. Preliminary analysis of locomotion in true microgravity revealed a substantial inhibition of cellular movement in Type I collagen. Thus, the rotating-wall vessel culture system provides a model for analyzing the microgravity-induced inhibition of lymphocyte locomotion and the investigation of the mechanisms related to lymphocyte movement.
    Keywords: Life Sciences (General)
    Type: In vitro cellular & developmental biology. Animal (ISSN 1071-2690); Volume 33; 5; 398-405
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Nonlinear ARMA models for the D(st) index and their physical interpretation (1996)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Time series models successfully reproduce or predict geomagnetic activity indices from solar wind parameters. A method is presented that converts a type of nonlinear filter, the nonlinear Autoregressive Moving Average (ARMA) model to the nonlinear damped oscillator physical model. The oscillator parameters, the growth and decay, the oscillation frequencies and the coupling strength to the input are derived from the filter coefficients. Mathematical methods are derived to obtain unique and consistent filter coefficients while keeping the prediction error low. These methods are applied to an oscillator model for the Dst geomagnetic index driven by the solar wind input. A data set is examined in two ways: the model parameters are calculated as averages over short time intervals, and a nonlinear ARMA model is calculated and the model parameters are derived as a function of the phase space.
    Keywords: Geophysics
    Type: ; 639-644
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Functional and cellular adaptations of rodent skeletal muscle to weightlessness (1995)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This paper describes the affects of microgravity upon three key cellular levels (functional, protein, and mRNA) that are linked to one another. It is clear that at each of these levels, microgravity produces rapid and substantial alterations. One of the key challenges facing the life science community is the development of effective countermeasures that prevent the loss of muscle function as described in this paper. The development of optimal countermeasures, however, awaits a clearer understanding of events occurring at the levels of transcription, translation, and degradation.
    Keywords: Life Sciences (General)
    Type: Journal of Gravitational Physiology, Volume 2, No. 1; 39-42
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Geopotential Error Analysis from Satellite Gradiometer and Global Positioning System Observables on Parallel Architecture (1997)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The recovery of a high resolution geopotential from satellite gradiometer observations motivates the examination of high performance computational techniques. The primary subject matter addresses specifically the use of satellite gradiometer and GPS observations to form and invert the normal matrix associated with a large degree and order geopotential solution. Memory resident and out-of-core parallel linear algebra techniques along with data parallel batch algorithms form the foundation of the least squares application structure. A secondary topic includes the adoption of object oriented programming techniques to enhance modularity and reusability of code. Applications implementing the parallel and object oriented methods successfully calculate the degree variance for a degree and order 110 geopotential solution on 32 processors of the Cray T3E. The memory resident gradiometer application exhibits an overall application performance of 5.4 Gflops, and the out-of-core linear solver exhibits an overall performance of 2.4 Gflops. The combination solution derived from a sun synchronous gradiometer orbit produce average geoid height variances of 17 millimeters.
    Keywords: Geophysics
    Type: NASA/CR-97-205884 , NAS 1.26:205884 , CSR-97-5
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Solar Wind-Magnetosphere Coupling During an Isolated Substorm Event: A Multispacecraft ISTP Study (1997)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Multispacecraft data from the upstream solar wind, polar cusp, and inner magnetotail are used to show that the polar ionosphere responds within a few minutes to a southward IMF turning, whereas the inner tail signatures are visible within ten min from the southward turning. Comparison of two subsequent substorm onsets, one during southward and the other during northward IMF, demonstrates the dependence of the expansion phase characteristics on the external driving conditions. Both onsets are shown to have initiated in the midtail, with signatures in the inner tail and auroral oval following a few minutes later.
    Keywords: Geophysics
    Type: NASA-CR-205242 , Paper-97GL00816 , NAS 1.26:205242 , Geophysical Research Letters (ISSN 0094-8534); 24; 8; 983-986
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Multi-Instrument Analysis of a Traveling Convection Vortex Event on July 24, 1996 Coordinated with the Polar UVI (1998)
    In:  Other Sources
    Details
    Publication Date: 2019-07-17
    Description: We present the analysis of a coordinated set of observations from the POLAR Ultraviolet Imager (UVI), ground magnetometers, incoherent scatter radar, solar wind monitors, DMSP and GOES satellites, focused on a traveling convection vortex (TCV) event on 24th July 1996. Starting at approximately 10:48 UT, around magnetometers in Greenland and northern Canada observe pulsations consistent with the passing overhead of a series of alternating TCV filed-aligned current pairs. Azimuthal scans by the Sondrestrom incoherent scatter radar located near Kangerlussuaq (formerly Sondrestrom), Greenland, at this time show strong modulation in the strength and direction of ionospheric plasma flow. The magnetometer pulsations grow in magnitude over the next hour, peaking in intensity at 11:39 UT, at which time images form the UVI instrument show a localized intensification of auroral emissions over central and western Greenland. Subsequent images show the intensification grow in strength and propagate westward (tailward) until approximately 11:58 UT at which time the intensification fades. These observations are consistent with the westward passage of two pairs of moderately intense TCVs over central Greenland followed by a third very intense TCV pair. The intensification of auroral emissions at 11:39 UT is associated with the trailing vortex of the third TCV pair, thought to be the result of an upward field aligned current. The modulated flow observed by the radar is the result of the strong electric fields associated with the impulsive TCV related field aligned current systems as they pass through the field of view of the radar. Measurements of the solar wind from the V;IND and IMP-8 spacecraft suggest that a pressure change may be responsible for triggering the first two pairs of TCVS, and that a subsequent sudden change in the orientation of the interplanetary magnetic field may have produced the intensification of the third TCV pair and the associated auroral brightening. Magnetometer data from the GOES satellite located over the eastern United States at geostationary orbit is consistent with a series of field-aligned moving tailward past the satellite. DMSP particle data indicated that the TCVs occur on field lines which map to the boundary plasma sheet (BPS).
    Keywords: Geophysics
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...