ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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  (6)
  • Mutation  (2)
  • SPACECRAFT DESIGN, TESTING AND PERFORMANCE  (2)
  • 1990-1994  (10)
  • 1
    Publication Date: 1994-09-23
    Description: The proposal that nitric oxide (NO) or its reactant products mediate toxicity in brain remains controversial in part because of the use of nonselective agents that block NO formation in neuronal, glial, and vascular compartments. In mutant mice deficient in neuronal NO synthase (NOS) activity, infarct volumes decreased significantly 24 and 72 hours after middle cerebral artery occlusion, and the neurological deficits were less than those in normal mice. This result could not be accounted for by differences in blood flow or vascular anatomy. However, infarct size in the mutant became larger after endothelial NOS inhibition by nitro-L-arginine administration. Hence, neuronal NO production appears to exacerbate acute ischemic injury, whereas vascular NO protects after middle cerebral artery occlusion. The data emphasize the importance of developing selective inhibitors of the neuronal isoform.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Huang, Z -- Huang, P L -- Panahian, N -- Dalkara, T -- Fishman, M C -- Moskowitz, M A -- NS10828/NS/NINDS NIH HHS/ -- NS2636/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1994 Sep 23;265(5180):1883-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Stroke Research Laboratory, Massachusetts General Hospital, Charlestown 02129.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7522345" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Oxidoreductases/antagonists & inhibitors/deficiency/*metabolism ; Animals ; Arginine/analogs & derivatives/pharmacology ; Brain/enzymology/*metabolism ; Brain Ischemia/complications/*metabolism ; Cerebral Infarction/*etiology ; Cerebrovascular Circulation ; Female ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Mutation ; Neurons/*enzymology ; Nitric Oxide/*metabolism ; Nitric Oxide Synthase ; Nitroarginine
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 1994-07-22
    Description: Long-term potentiation (LTP) is a persistent increase in synaptic strength implicated in certain forms of learning and memory. In the CA1 region of the hippocampus, LTP is thought to involve the release of one or more retrograde messengers from the postsynaptic cell that act on the presynaptic terminal to enhance transmitter release. One candidate retrograde messenger is the membrane-permeant gas nitric oxide (NO), which in the brain is released after activation of the neuronal-specific NO synthase isoform (nNOS). To assess the importance of NO in hippocampal synaptic plasticity, LTP was examined in mice where the gene encoding nNOS was disrupted by gene targeting. In nNOS- mice, LTP induced by weak intensity tetanic stimulation was normal except for a slight reduction in comparison to that in wild-type mice and was blocked by NOS inhibitors, just as it was in wild-type mice. Immunocytochemical studies indicate that in the nNOS- mice as in wild-type mice, the endothelial form of NOS (eNOS) is expressed in CA1 neurons. These findings suggest that eNOS, rather than nNOS, generates NO within the postsynaptic cell during LTP.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉O'Dell, T J -- Huang, P L -- Dawson, T M -- Dinerman, J L -- Snyder, S H -- Kandel, E R -- Fishman, M C -- DA-00074/DA/NIDA NIH HHS/ -- DA-00266/DA/NIDA NIH HHS/ -- MH-45923/MH/NIMH NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1994 Jul 22;265(5171):542-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, College of Physicians and Surgeons of Columbia University, New York, NY 10032.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7518615" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Oxidoreductases/antagonists & inhibitors/genetics/*metabolism ; Animals ; Arginine/*analogs & derivatives/pharmacology ; Electric Stimulation ; Endothelium/enzymology ; Hippocampus/drug effects/enzymology/*physiology ; In Vitro Techniques ; *Long-Term Potentiation/drug effects ; Mice ; Mutation ; Nitric Oxide/*metabolism ; Nitric Oxide Synthase ; Nitroarginine ; Pyramidal Cells/drug effects/enzymology/*physiology ; Synaptic Transmission/drug effects
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2011-08-24
    Description: The BATSE on-board burst system has been triggered by over 400 terrestrial electron precipitation events. These are the single largest cause of false triggers. Bremsstrahlung is generated as the precipitating electrons interact in the Earth's atmosphere, or in the spacecraft, and this radiation is detected by the Large Area Detectors, often triggering the instrument into burst mode. Several examples of such events are presented here, and the different classes of events are described. A possible correlation of events to strong magnetospheric activity is presented, and the association of a sub-set of events to a powerful VLF transmitter on the western coast of Australia is described.
    Keywords: GEOPHYSICS
    Type: In: Gamma-ray bursts; Proceedings of the Workshop, Univ. of Alabama, Huntsville, Oct. 16-18, 1991 (A93-40051 16-93); p. 373-377.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2011-08-24
    Description: Two independent sets of data, one of aerosols from an airborne lidar system, and one of ozone from ozonesonde measurements indicate that significant ozone decreases may have happened as a result of the injection of debris by the Mt. Pinatubo volcano in June 1991. The amount of this reduction maximizes at 24-25 km, near the peak of the aerosol distribution, though a deficit is seen throughout the lower stratosphere between 19 and 28 km. The greatest differences observed prior and subsequent to the eruptions at these altitudes is 18-20 percent.
    Keywords: GEOPHYSICS
    Type: Geophysical Research Letters (ISSN 0094-8276); 19; 11, J
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2011-08-19
    Description: Significant quantities of Be-7 have been found on the leading edge of the Long Duration Exposure Facility (LDEF), which was returned to earth after almost six years in space. Although the absolute atmospheric concentration of Be-7 needed to explain this detection is extremely small, its concentration at LDEF's altitude must be several orders of magnitude higher than in the stratosphere below, where it is produced by cosmic-ray reactions with atmospheric nitrogen and oxygen nuclei. The detection may lead to the use of Be-7 as an exoatmospheric tracer as well as to studies of surface interactions in space.
    Keywords: GEOPHYSICS
    Type: Nature (ISSN 0028-0836); 349; 678-680
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2013-08-31
    Description: The discovery of the cosmogenic radionuclide Be-7 on the front surface (and the front surface only) of the Long Duration Exposure Facility (LDEF) spacecraft has opened opportunities to investigate new phenomena in several disciplines of space science. The experiments performed for this work show that the Be-7 results only if the source of the isotope is the atmosphere through which the spacecraft passed. We should expect that the uptake of beryllium in such circumstances will depend on the chemical form of the Be and the chemical nature of the substrate. It was found that the observed concentration of Be-7 does, in fact, differ between metal surfaces and organic surfaces such as PTFE (teflon). It is noted, however, that: (1) organic surfaces, even PTFE, are etched by the atomic oxygen found under these orbital conditions, and (2) the relative velocity of the species is 8 km(exp -1)s relative to the surface and the interaction chemistry and physics may differ from the norm. The Be-7 is formed by spallation of O and N nuclei under cosmic ray proton bombardment. The principal source region is at altitudes of 12-15 km. While very small quantities are produced above 300 km, the amount measured on the LDEF was 3 to 4 orders of magnitude higher than expected from production at orbital attitude. The most reasonable explanation is that Be-7 is rapidly transported from low altitudes by some unknown mechanism. The process must take place on a time scale similar to the half-life of the isotope (53 days). Many other isotopes are produced by cosmic ray reactions, and some of these are suited to measurement by the extremely sensitive methods of accelerator mass spectrometry. A program was initiated to search for these isotopes and it is hoped that such studies will provide new methods for studying mixing in the upper atmosphere.
    Keywords: SPACECRAFT DESIGN, TESTING AND PERFORMANCE
    Type: Analysis of Surfaces from the LDEF A0114, Phase 4; 15 p
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2019-06-28
    Description: Conceptual space station common module power management and distribution (SSM/PMAD) network layouts and detailed network evaluations were developed. Individual pieces of hardware to be developed for the SSM/PMAD test bed were identified. A technology assessment was developed to identify pieces of equipment requiring development effort. Equipment lists were developed from the previously selected network schematics. Additionally, functional requirements for the network equipment as well as other requirements which affected the suitability of specific items for use on the Space Station Program were identified. Assembly requirements were derived based on the SSM/PMAD developed requirements and on the selected SSM/PMAD network concepts. Basic requirements and simplified design block diagrams are included. DC remote power controllers were successfully integrated into the DC Marshall Space Flight Center breadboard. Two DC remote power controller (RPC) boards experienced mechanical failure of UES 706 stud-mounted diodes during mechanical installation of the boards into the system. These broken diodes caused input to output shorting of the RPC's. The UES 706 diodes were replaced on these RPC's which eliminated the problem. The DC RPC's as existing in the present breadboard configuration do not provide ground fault protection because the RPC was designed to only switch the hot side current. If ground fault protection were to be implemented, it would be necessary to design the system so the RPC switched both the hot and the return sides of power.
    Keywords: SPACECRAFT DESIGN, TESTING AND PERFORMANCE
    Type: NASA-CR-184034 , NAS 1.26:184034 , MCR-90-536
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2019-08-28
    Description: An analysis of 33 ozonesonde launches in Brazzaville, Congo (4 deg S, 15 deg E), between June 1990 and May 1991 is presented. The data indicate highest tropospheric amounts between June and early October, coincident with the dry season and with the presence of enhanced widespread biomass burning. The seasonal cycle of ozone derived from the ozonesonde measurements is in good agreement with the climatological seasonal cycle inferred from the use of satellite data amd both seasonal cycles peak in September. Averaged throughout the year, the integrated amount of ozone derived from the ozonesondes is 44 Dobson units (DU) and is 39 DU using the satellite data. Within the troposphere the highest partial pressures are generally found at pressure levels near 700 mbar (about 3 km). Using simultaneous ozonesonde data from Ascension Island (8 deg S, 15 deg W), examples are presented illustrating that differences in the troposphere are primarily responsible for the observed spatial gradients of total ozone observed by TOMS.
    Keywords: GEOPHYSICS
    Type: Journal of Geophysical Research (ISSN 0148-0227); 97; D12,; 12
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2019-07-12
    Description: An analysis of more than 22,000 ozone profiles from Stratospheric Aerosol and Gas Experiment I (SAGE I) (1979-1981) and SAGE II (1984-1987) between 50 deg N and 50 deg S is used in conjunction with 9 years (1979-1987) of daily global depictions of total ozone from the TOMS instrument aboard Nimbus 7 to investigate the spatial distribution and seasonal cycle of the integrated amount of ozone in the troposphere. In the tropics, highest concentrations are found in the eastern Atlantic Ocean downwind (west) of Africa and maximize during the time when biomass burning is most prevalent, between July and October. A different seasonal cycle in the tropics is also observed over Indonesia, where a relative maximum is present in the March-April time frame, likewise consistent with when biomass burning is most prevalent. At mid-latitudes, highest concentrations are found downwind of Asia and maximize in the summer. Relatively higher amounts of tropospheric ozone are similarly observed downwind of North America and Europe. At mid-latitudes, the ratio between the amount of tropospheric ozone in the Northern Hemisphere and the amount in the Southern Hemisphere is 1.4, in good agreement with in situ measurements.
    Keywords: GEOPHYSICS
    Type: Journal of Geophysical Research (ISSN 0148-0227); 95; 3599-361
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2019-08-27
    Description: Measurements from two independent satellite data sets have been used to derive the climatology of the integrated amount of ozone in the troposphere. These data have led to the finding that large amounts of ozone pollution are generated by anthropogenic activity originating from both the industrialized regions of the Northern Hemisphere and from the southern tropical regions of Africa. To verify the existence of this ozone anomaly over this region of the world, an ozonesonde capability has been established at Ascension Island, located downwind of the primary source region of this ozone pollution, which likely results from the photochemical oxidation of emissions emanating from the widespread burning of savanna. These first ozonesonde profiles suggest that much of the ozone generated over Africa during the 'burning season' (primarily July-October) reaches Ascension Island. These high levels of ozone in the lower troposphere become much lower by December. Elevated ozone concentrations in the middle troposphere are once again evident in February, which may be the result of biomass burning emissions being transported from western and northern Africa.
    Keywords: GEOPHYSICS
    Type: Journal of Atmospheric and Terrestrial Physics (ISSN 0021-9169); 54; 5, Ma; 589-597
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...