8,697 research outputs found

    Review of AIDS development

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    The operation and implementation of the aircraft integrated data system AIDS are described. The system is described as an engineering tool with strong emphasis on analysis of recorded information. The AIDS is primarily directed to the monitoring of parameters related to: the safety of the flight; the performance of the aircraft; the performance of the flight guidance system; and the performance and condition of the engines. The system provide short term trend analysis on a trend chart that is updated by the flight engineer on every flight that lasts more than 4 flight hours. Engine data prints are automatically presented during take-off and in the case of limit excedance, e.g., the print shows an automatically reported impending hotstarts on engine nr. 1. Other significant features are reported

    Good soil: a good start

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    Soil plays a central role in plant production and the environment. Organic growers depend on the soil’s natural richness and resistance to disease. In order to foster these essential qualities, farmers and researchers are looking at ways to stimulate soil life, optimise soil structure and close nutrient cycle

    Twenty Years of Timing SS433

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    We present observations of the optical ``moving lines'' in spectra of the Galactic relativistic jet source SS433 spread over a twenty year baseline from 1979 to 1999. The red/blue-shifts of the lines reveal the apparent precession of the jet axis in SS433, and we present a new determination of the precession parameters based on these data. We investigate the amplitude and nature of time- and phase-dependent deviations from the kinematic model for the jet precession, including an upper limit on any precessional period derivative of P˙<5×10−5\dot P < 5 \times 10^{-5}. We also dicuss the implications of these results for the origins of the relativistic jets in SS433.Comment: 21 pages, including 9 figures. To appear in the Astrophysical Journa

    First VLBA Images of the Nuclei in 3CR Lobe-dominated Quasars

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    We report the first VLBA images of the nuclei in eight objects from the 3CR complete sample of 25 lobe-dominated quasars (LDQs): 3C 207, 3C 208, 3C 212, 3C 245, 3C 249.1, 3C 263, 3C 270.1, and 3C 275.1. These images reveal core-jet structures of considerable extent and complexity. In combination with earlier VLBI work on the 3CR LDQ sample, the partial distribution of apparent parsec-scale jet speeds for ten objects is relatively flat up to ~ 5h^(−1) c, or perhaps even ~ 10h^(−1) c. While this is not inconsistent with simple beaming models and quasar-FR II radio galaxy unification, it is crucial to obtain the complete speed distribution for truly definitive tests. Work is in progress on multi-frequency, dual-polarization, and phase-referencing VLBA observations on selected objects in the sample

    Farmers, food and climate change: ensuring community-based adaptation is mainstreamed into agricultural programmes

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    Climate change creates widespread risks for food production. As climate impacts are often locally specific, it is imperative that large-scale initiatives to support smallholder farmers consider local priorities and integrate lessons from successful autonomous adaptation efforts. This article explores how large-scale programmes for smallholder adaptation to climate change might link effectively with community-led adaptation initiatives. Drawing on experiences in Bangladesh, Mozambique, Uganda and India, this article identifies key success factors and barriers for considering local priorities, capacities and lessons in large-scale adaptation programmes. It highlights the key roles of extension services and farmers' organizations as mechanisms for linking between national-level and community-level adaptation, and a range of other success factors which include participative and locally driven vulnerability assessments, tailoring of adaptation technologies to local contexts, mapping local institutions and working in partnership across institutions. Barriers include weak governance, gaps in the regulatory and policy environment, high opportunity costs, low literacy and underdeveloped markets. The article concludes that mainstreaming climate adaptation into large-scale agricultural initiatives requires not only integration of lessons from community-based adaptation, but also the building of inclusive governance to ensure smallholders can engage with those policies and processes affecting their vulnerability

    Inferring Rn-222 soil fluxes from ambient Rn-222 activity and eddy covariance measurements of CO2

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    We present a new methodology, which we call Single Pair of Observations Technique with Eddy Covariance (SPOT-EC), to estimate regional-scale surface fluxes of 222Rn from tower-based observations of 222Rn activity concentration, CO2 mole fractions and direct CO2 flux measurements from eddy covariance. For specific events, the regional (222Rn) surface flux is calculated from short-term changes in ambient (222Rn) activity concentration scaled by the ratio of the mean CO2 surface flux for the specific event to the change in its observed mole fraction. The resulting 222Rn surface emissions are integrated in time (between the moment of observation and the last prior background levels) and space (i.e. over the footprint of the observations). The measurement uncertainty obtained is about ±15 % for diurnal events and about ±10 % for longer-term (e.g. seasonal or annual) means. The method does not provide continuous observations, but reliable daily averages can be obtained. We applied our method to in situ observations from two sites in the Netherlands: Cabauw station (CBW) and Lutjewad station (LUT). For LUT, which is an intensive agricultural site, we estimated a mean 222Rn surface flux of (0.29 ± 0.02) atoms cm−2 s−1 with values  > 0.5 atoms cm−2 s−1 to the south and south-east. For CBW we estimated a mean 222Rn surface flux of (0.63 ± 0.04) atoms cm−2 s−1. The highest values were observed to the south-west, where the soil type is mainly river clay. For both stations good agreement was found between our results and those from measurements with soil chambers and two recently published 222Rn soil flux maps for Europe. At both sites, large spatial and temporal variability of 222Rn surface fluxes were observed which would be impractical to measure with a soil chamber. SPOT-EC, therefore, offers an important new tool for estimating regional-scale 222Rn surface fluxes. Practical applications furthermore include calibration of process-based 222Rn soil flux models, validation of atmospheric transport models and performing regional-scale inversions, e.g. of greenhouse gases via the SPOT 222Rn-tracer method

    Current standards and ethical landscape of engineered tissues—3D bioprinting perspective

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    Tissue engineering is an evolving multi-disciplinary field with cutting-edge technologies and innovative scientific perceptions that promise functional regeneration of damaged tissues/organs. Tissue engineered medical products (TEMPs) are biomaterial-cell products or a cell-drug combination which is injected, implanted or topically applied in the course of a therapeutic or diagnostic procedure. Current tissue engineering strategies aim at 3D printing/bioprinting that uses cells and polymers to construct living tissues/organs in a layer-by-layer fashion with high 3D precision. However, unlike conventional drugs or therapeutics, TEMPs and 3D bioprinted tissues are novel therapeutics and need different regulatory protocols for clinical trials and commercialization processes. Therefore, it is essential to understand the complexity of raw materials, cellular components, and manufacturing procedures to establish standards that can help to translate these products from bench to bedside. These complexities are reflected in the regulations and standards that are globally in practice to prevent any compromise or undue risks to patients. This review comprehensively describes the current legislations, standards for TEMPs with a special emphasis on 3D bioprinted tissues. Based on these overviews, challenges in the clinical translation of TEMPs & 3D bioprinted tissues/organs along with their ethical concerns and future perspectives are discussed

    Quality of life in breast cancer patients with cancer treatment-related cardiac dysfunction: a qualitative study

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    Contains fulltext : 251384.pdf (Publisher’s version ) (Open Access)BACKGROUND: Although improved breast cancer (BC) treatment has decreased mortality, these anti-cancer regimens may have serious cardiovascular side effects that affect patients' long-term prognosis and quality of life (QoL). BC patients with cancer treatment-related cardiac dysfunction (CTRCD) can suffer from a variety of symptoms, such as dyspnoea and fatigue. The impact of CTRCD after BC treatment on patients' daily life has not been qualitatively explored yet. AIMS: This study aims to explore the influence of CTRCD on QoL of women with BC, as defined by the concept of positive health. Second, we aim to evaluate the personal experience with cardiac surveillance during the BC trajectory. METHODS AND RESULTS: A qualitative study with semi-structured interviews was conducted and thematically analysed to explore the QoL and healthcare experiences of BC patients with CTRCD. Twelve patients participated in this study. Five themes are selected in response to the study objective: (i) patients: overwhelming fatigue, (ii) patients: mental burden of anxiety, (iii) social setting: lack of understanding and acceptance, (iv) medical specialists: lack of knowledge and acknowledgement, and (v) patients: need for personalized care. CONCLUSION: This study identified core components of the impact CTRCD has on the QoL of BC patients. Patients experienced an increased health-related burden due to CTRCD, affecting their physical, social, and psychosocial well-being. Healthcare experiences were largely affected by a lack of acknowledgement and professional communication. Patients underlined the need for personalized care during follow-up

    Comparison of urine with urethral swabs for the detection of Chlamydia trachomatis in men attending an STD clinic

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    Urethral swabs and first-catch urine specimens for the detection of Chlamydia trachomatis were collected from 370 black men with urethritis who attended a sexually transmitted disease (STD) clinic in Pretoria. An enzyme immunoassay (EIA) for C. trachomatis was carried out on all urethral swabs and urine specimens. Chlamydial culture and a direct immunofluorescent antibody (DFA) test (Imagen, Dako, UK) were also carried out on urethral swabs; DFA was used for confirmation of urine EIA positives.Based on culture and/or DFA, C. trachomatis was detected in 96 (26%) urethral swab specimens. The sensitivity of urine EIA investigation was 94% and the specificity 99%, compared with those of urethral swab EIA which. were 97% and 99% respectively. The positive and negative predictive values for urine were 96% and 98% compared with 96% and 99% respectively for urethral swabs. Urine examination was therefore sensitive and specific compared with urethral swab examination in these STD patients. In view of this, the advantage of urine as an alternative to urethral swabs for C. trachomatis detection is that sampling is non-invasive and non-traumatic
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