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  • 1
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 1658-1660 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effect of strain, due to a buried, nominally 6 ML Ge quantum dot layer, upon the growth of subsequent Ge layers grown by gas source molecular beam epitaxy has been investigated. A series of samples were grown at 700 °C with a nominally 6 ML Ge layer followed by a 30 nm Si spacer and then a second, thinner Ge layer. In each sample, the thickness of the second Ge layer was varied (2, 3, and 4 ML). Atomic force microscopy shows that in the second Ge layer islands form at thicknesses below the established critical thickness for this material system. This is confirmed by transmission electron microscopy images which also show the quantum dots in the second layers are stacked above those in the first layer, the island growth in the thin Ge layer being seeded by the strain field from the buried Ge islands. Photoluminescence results show a luminescence feature attributed to the strain-controlled quantum dots in the thin Ge layer. This band has properties similar to the frequently observed Ge dot luminescence but is observed at higher energies, depending upon the nominal thickness of the second Ge layer. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 80 (2002), S. 1328-1330 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report on two-photon absorption (TPA) photocurrent in semiconductor microcavities. We experimentally show a substantial increase in the TPA photocurrent generated, at resonance, in a GaAlAs/GaAs microcavity designed for TPA operation at ∼890 nm. An enhancement factor of ∼12 000 of the photocurrent is obtained via the microcavity effect, which could have an important impact on the use of TPA devices for high speed switching and sampling applications. Our results also show the implications of the cavity photon lifetime on autocorrelation traces measured using TPA in semiconductor microcavities. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 50 (2003), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Water and environment journal 17 (2003), S. 0 
    ISSN: 1747-6593
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: River corridors in urban environments provide areas of biodiversity which are important for both aesthetic and economic reasons. A physical habitat model, which was used to assess urban rivers in Birmingham, UK, was applied to pairs of selected reaches to represent differing levels of habitat diversity on three rivers. The results for different life-stages of dace, roach and chub suggest that the worst physical habitat occurs in highly modified channels and at the highest flows. Four scenarios, which were designed to represent alterations in flow regime caused by changes in management practices, were calculated using the hydrological model. Changes in physical habitat created by changes to the flow regime were assessed using a consistent, replicable method. It was shown that an increase in runoff would have detrimental effects in all cases, and that less engineered sites would benefit more from flow reductions. The lack of a suitable habitat for fry is shown to be a limiting factor for fish at all sites.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Water and environment journal 18 (2004), S. 0 
    ISSN: 1747-6593
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: This paper describes the evolution of methods to set environmental flows in England and Wales. Problems and challenges are reviewed in the context of recent legislative developments, and examples are given of different conceptual approaches. Scenario-based approaches have evolved as a pragmatic means to resolve competing uses of water; in contrast, approaches based on ecological objectives aim to meet more consistent goals. Where rivers or associated wetlands have been designated under national or European conservation legislation, broad ecological objectives are already under discussion. Furthermore, the European Water Framework Directive now requires good ecological status, or its equivalent, to be reached in all waters. Recently, the Environment Agency has developed a new process for managing abstractions in England and Wales; this includes a common methodology for the setting of environmental flows using objective methods.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biomedical Engineering 4 (2002), S. 93-107 
    ISSN: 1523-9829
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Technology , Medicine
    Notes: Abstract The new field of therapeutic aerosol bioengineering (TAB), driven primarily by the medical need for inhaled insulin, is now expanding to address medical needs ranging from respiratory to systemic diseases, including asthma, growth deficiency, and pain. Bioengineering of therapeutic aerosols involves a level of aerosol particle design absent in traditional therapeutic aerosols, which are created by conventionally spraying a liquid solution or suspension of drug or milling and mixing a dry drug form into respirable particles. Bioengineered particles may be created in liquid form from devices specially designed to create an unusually fine size distribution, possibly with special purity properties, or solid particles that possess a mixture of drug and excipient, with designed shape, size, porosity, and drug release characteristics. Such aerosols have enabled several high-visibility clinical programs of inhaled insulin, as well as earlier-stage programs involving inhaled morphine, growth hormone, beta-interferon, alpha-1-antitrypsin, and several asthma drugs. The design of these aerosols, limited by partial knowledge of the lungs' physiological environment, and driven largely at this stage by market forces, relies on a mixture of new and old science, pharmaceutical science intuition, and a degree of biological-impact empiricism that speaks to the importance of an increased level of academic involvement.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Anthropology 32 (2003), S. 163-181 
    ISSN: 0084-6570
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Ethnic Sciences , Biology
    Notes: The social brain (or Machiavellian Intelligence) hypothesis was proposed to explain primates' unusually large brains: It argues that the cognitive demands of living in complexly bonded social groups selected for increases in executive brain (principally neocortex). The evidence for this and alternative hypotheses is reviewed. Although there remain difficulties of interpretation, the bulk of the evidence comes down in favor of the social brain hypothesis. The extent to which the cognitive demands of bonding large intensely social groups involve aspects of social cognition, such as theory of mind, is explored. These findings are then related to the evolution of social group size, language, and culture within the hominid lineage.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science, Ltd
    Plant, cell & environment 26 (2003), S. 0 
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The mobility of Cd in potato plants (Solanum tuberosum) was examined using both short-term radioisotopic labelling with 109Cd and long-term growth experiments in soil supplemented with Cd, with an emphasis on the pathways through which Cd is taken up by tubers. Split-pot experiments showed that tubers and their associated stolons and stolon roots contribute only a minor fraction to the overall Cd absorption by the plant. Most of the Cd was absorbed by the basal roots. 109Cd absorbed from the soil was rapidly exported to other parts of the plant, especially the stem, with significant amounts appearing in the tubers within 30 h. Application of 109Cd to leaves showed that Cd can be rapidly distributed via the phloem to all tissues. The results suggest that unlike Ca, Cd has high mobility in plants in both xylem and phloem, and that stems may have an important role in transfer between these two pathways.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Melbourne, Australia : Blackwell Science Pty
    Nephrology 9 (2004), S. 0 
    ISSN: 1440-1797
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: SUMMARY:  Non-traumatic rupture of large tendons is identified as a contributor to morbidity in patients who receive haemodialysis. The injury is likely to become more common as the duration of survival on dialysis extends. A number of predisposing factors leading to tendon injury have been identified in the literature, including secondary hyperparathyroidism, β2-microglobulin associated amyloidosis, corticosteroid treatment and fluoroquinolone antibiotic use. This is a case report of a 31-year-old male who presented with simultaneous large tendon ruptures following epileptiform seizures. These occurred after 10 years of treatment for end-stage renal failure, including haemodialysis, with progressive secondary hyperparathyroidism. A review of the literature confirms progressive hyperparathyroidism as an important risk factor for large tendon rupture in patients on haemodialysis.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Oxford BSL : Blackwell Science Ltd
    Clinical & experimental allergy 30 (2000), S. 0 
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: There is considerable interest in the role of different candidate loci in the development of asthma. This study investigates the association between asthma severity and previously identified polymorphisms at two sites within the β2-adrenergic receptor (β2AR) gene: the Arg16→Gly16 and Gln27→Glu27 alleles.〈section xml:id="abs1-2"〉〈title type="main"〉MethodsRestriction enzyme analysis of amplified β2AR gene products (PCR-RFLP) was used to analyse the frequency of the Arg16→Gly16 and Gln27→Glu27 polymorphisms within the β2AR gene in 95 severe asthmatic patients (with a markedly increased risk of death from asthma), 59 mild asthmatic patients, and a control group of 92 nonasthmatic subjects.〈section xml:id="abs1-3"〉〈title type="main"〉ResultsThe Gly16 polymorphism was significantly associated with asthma severity with odds ratios (95% CI) for the Gly16 allele being 1.56 (1.02–2.40, P = 0.04) and 0.98 (0.61–1.57, P = 0.92) for the severe and mild asthma groups, respectively. The corresponding odds ratios (95% CI) for Gly16 homozygotes were 1.91 (0.82–4.41, P = 0.13) and 0.82 (0.35–1.92, P = 0.65) for the severe and mild asthma groups, respectively. There was no significant association between either polymorphism at amino acid 27 and asthma or asthma severity.〈section xml:id="abs1-4"〉〈title type="main"〉ConclusionsWe conclude that the polymorphisms of amino acids 16 and 27 of the β2AR gene are not associated with the development of asthma per se, but that the Gly16 polymorphism may play a role in the pathogenesis of asthma severity.
    Type of Medium: Electronic Resource
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