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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 68 (1997), S. 1484-1494 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The wavelet transform has emerged as an important tool for the analysis of intermittent and nonstationary signals. This article addresses implementation issues of a digital continuous wavelet transform that is sufficiently general that any continuous wavelet can be used. Working equations are derived for wavelet sampling, aliasing, and scale population by using the band-pass filter interpretation of wavelet functions. The implementation procedure is applied to the Morlet wavelet in detail as an example. Finally, the Morlet wavelet is applied to velocity fluctuations measured in a subsonic wake undergoing transition to turbulence. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 51 (1997), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The occurrence of post-F1 generation hybrids between common bream and roach in natural populations has still to be qualified. To do this, common bream, roach, F1 and F2 hybrid progeny were produced under controlled conditions. All progeny groups exhibited overlaps in the ranges of their meristic characters. Discriminant analysis of meristic data combined with allozymes allowed identification of post-Fl hybrids. Enzyme electrophoresis showed Fl progeny to be heterozygous at diagnostic loci. Back-crossed F2 progeny had a mixture of homozygosity and heterozygosity at diagnostic loci. Meristic and genetic analysis of fish from a natural population indicated that they were all F1 hybrids. Post-Fl hybridization cannot be ruled out from natural populations because Fl hybrids are known to be fertile. It is suggested that post-Fl hybrids were not detected either because of their low incidence of occurrence or due to biological phenomenon Such as inferior fitness.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 99 (1997), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Light harvesting and utilization by chloroplasts located near the adaxial vs the abaxial surface of sun and shade leaves were examined by fluorometry in two herbaceous perennials that differed in their anatomy and leaf inclination. Leaves of Thermopsis montana had well-developed palisade and spongy mesophyll whereas the photosynthetic tissue of Smilacina stellata consisted of spongy mesophyll only. Leaf orientation depended upon the irradiance during leaf development. When grown under low-light levels, leaves of S. stellata and T. montana were nearly horizontal, whereas under high-light levels, S. stellata leaves and T. montana leaves were inclined 600 and 300, respectively. Leaf inclination increased the amount of light that was intercepted by the lower leaf surfaces and affected the photosynthetic properties of the chloroplasts located near the abaxial leaf surface. The slowest rates of quinone pool reduction and reoxidation were found in chloroplasts located near the adaxial leaf surface of T. montana plants grown under high light, indicating large quinone pools in these chloroplasts. Chloroplasts near the abaxial surface of low-light leaves had lower light utilization capacities as shown by photochemical quenching measurements. The amount of photosystem II (PSII) down regulation, measured from each leaf surface, was also found to be influenced by irradiance and leaf inclination. The greatest difference between down regulation monitored from the adaxial vs abaxial surfaces was found in plants with horizontal leaves. Different energy dissipation mechanisms may be employed by the two species. Values for down regulation in S. stellata were 2–3 times higher than those in T. montana, while the portion of the PSII population which was found to be QB nonreducing was 4–6 times lower in high light S. stellata leaves than in T. montana. All values of Stern-Volmer type nonphotochemical quenching (NPQ) from S. stellata leaves were similar when quenching analysis was performed at actinic irradiances that were higher than the irradiance to which the leaf surface was exposed during growth. In contrast, with T. montana, NPQ values from the abaxial leaf surface were up to 45% higher than those from the adaxial leaf surface regardless of growth conditions. The observed differences in chloroplast properties between species and between the adaxial and abaxial leaf surfaces may depend upon a complex interaction among light, leaf anatomy and leaf inclination.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1435-1463
    Keywords: Autoradiography ; substance P ; ontogenesis ; sudden infant death syndrome ; SIDS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The precise distribution of substance P (SP) binding sites in the human brainstem was investigated in normal cases (3 fetuses and 24 newborns) and in 9 cases of Sudden Infant Death Syndrome (SIDS) by in vitro quantitative autoradiography. We discussed the widely but uneven distribution of SP binding sites as regards to the role of SP in brainstem cardio-respiratory ontogenic control and its possible involvement in SIDS.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1438-1435
    Keywords: Diagnostic radiology ; Observer performance ; Radiology education
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of this study was to evaluate the etiology of significant false-negative computed tomographic (CT) interpretations by radiology residents on-call. Over a 1-year period, significant on-call false-negative CT interpretations were analyzed to determine whether errors were perceptual (i.e., the resident did not see the finding or findings) or cognitive (i.e., the resident did not recognize the implications or misinterpreted a finding or findings). Significant “misses” were defined as errors that delayed surgical treatment or misdirected management in a potentially life-threatening manner. A total of 12 significant false-negative interpretations occurred over a 1-year period. All head CT misses (extraaxial hemorrhage, pneumocephalus, contusion, subarachnoid hemorrhage due to ruptured aneurysm) were perceptual errors. Misses on thoracic, abdominal, and pelvic CT scans (2 abscesses, abdominal aortic aneurysm rupture, superior vena cava perforation due to catheter placement, ischemic bowel, liver laceration, hypoperfusion syndrome, appendicitis) were mixed (4 cognitive and 4 perceptual errors). Since the diagnostic possibilities of emergency head CT scans are limited, residents missed only subtle, perceptual manifestations and had little difficulty interpreting findings when they were correctly recognized. The gamut of diagnostic possibilities in the thorax, abdomen, and pelvis was more challenging to residents on-call; errors in both perception and interpretation arose with equal frequency, and the significant error rate was higher than that for head CT interpretation. Junior residents, who make most of the significant on-call errors, commonly feel overwhelmed in attempting to assimilate the knowledge required to take call. Prepartion needs to be extensive, yet it should be focused on areas that will engender optimal impact on after-hours performance. When preparing residents to interpret on-call CT studies, perceptual manifestations of neuroradiology should be emphasized, whereas a more comprehensive approach to thoracic, abdominal, and pelvic disorders needs to be stressed.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Biology and fertility of soils 24 (1997), S. 347-352 
    ISSN: 1432-0789
    Keywords: Key words Phosphate-solubilizing bacteria ; Hydroxyapatite ; Enterobacter agglomerans ; Organic acids ; Phosphate-solubilizing genes ; Rhizosphere ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Phosphate-solubilizing bacteria (PSB) possessing the ability to solubilize insoluble inorganic phosphate were isolated from the rhizosphere soil of wheat. A laboratory study was conducted to investigate the solubilization of phosphate by a known PSB, Enterobacter agglomerans, and by a genetically manipulated bacterium, Escherichia coli. A second laboratory study investigated the release of P from E. agglomerans compared with known acids. For the first laboratory study, a cosmid (pHC79) library of phosphate-solubilizing gene(s) from E. agglomerans chromosome DNA was constructed in E. coli JM109. The clone JM109 (pKKY) showing phosphate solubilization properties was screened on standard medium containing hydroxyapatite (HY). The P concentration significantly increased at 5 and 10 days for JM109 (pKKY) compared with JM109 (pHC79), the control. Although the P concentration increased, there was no significant change in their pHs. Furthermore, an increase in colony-forming units (CFUs) was seen at 5 and 10 days for JM109 (pKKY) but not for JM109 (pHC79). Artificial acidification of the culture medium with HCl, citric acid, oxalic acid, and lactic acid was achieved by shaking for 48h. Acidification with these selected acids solubilized more HY than E. agglomerans growing for 42h at similar pHs. However, a high P concentration was measured in culture medium with E. agglomerans growing for 84h despite similar pHs. Our results suggest that acid production may play an important role in HY solubilization, but is not the sole reason for the increase in P concentration in culture medium.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0789
    Keywords: Key words Organic acids ; Phosphate-solubilizing ; bacteria ; Vesicular-arbuscular mycorrhizae ; Glomus etunicatum ; Enterobacter agglomerans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The interaction of vesicular-arbuscular mycorrhizae (VAM) and phosphate-solubilizing bacteria (PSB) on plant growth, soil microbial activities, and the production of organic acids was studied in non-sterile soil containing hydroxyapatite and glucose. Glomus etunicatum (VAM), a fungus, and Enterobacter agglomerans, a bacterium able to solubilize insoluble phosphate, were used as inocula. Three treatments and a control were used: inoculation with E. agglomerans (treatment E), inoculation with G. etunicatum (treatment G), inoculation with E. agglomerans+G. etunicatum (treatment E+G) and the control (C). Inoculation with E, G, or E+G had increased plant growth by days 35, 55, and 75 compared with the control. Microbial biomass carbon (C) and alkaline phosphatase activity in the rhizosphere generally increased with time. Alkaline phosphatase activity was higher in treatments G and E+G compared with the control at 35 and 55 days. The highest acid phosphatase activity was observed in treatment E at 35 days; however, this markedly decreased with time. A significantly higher soluble phosphorus (P) concentration was observed in treatments E and E+G on day 55 compared with C. However, there was no significant difference in soluble P concentration in the rhizosphere between treatments with time. The P concentration was greatest in all treatments on day 55. The highest oxalic acid concentration was observed in the rhizosphere of the non-sterile soil in E+G on day 35. Total N and P uptake in plants from treatments E and G were higher compared with the control. However, the highest N and P uptake was observed in treatment E+G. This study suggests a synergistic interaction between E. agglomerans and G. etunicatum.
    Type of Medium: Electronic Resource
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