560 research outputs found

    Nitrogen and phosphorus budgets for the central Great Barrier Reef Shelf

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    Shelf-scale budgets were developed for the nutrient elements nitrogen (N) and phosphorus (P) in the central Great Barrier Reef between Cape Tribulation (I 60 S} and Dunk Island (ca. 18°S). The intent was to quantify: I} stocks of nutrients (nitrogen (N). phosphorus (P) and silicon (Si}) naturally occurring in central Great Barrier Reef waters; 2) natural gradients and variability in water column nutrient concentrations; 3} natural fluxes of nutrients into and out of shelf waters for comparison with anthropogenic or anthropogenically affected nutrient sources

    Biological and chemical oceanographic measurements in Far Northern Great Barrier Reef - February 1990

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    This report presents and sununarises the results of biological and chemical oceanographic sampling carried out in the far northern Great Barrier Reef during February 1990. The region sampled (ca. 11-13°S), lies adjacent to the eastern side of Cape York Peninsula, locations on which are under consideration for national park declaration, the construction of a rocket launching facility and silica sand mining. As little is known regarding the biological and chemical oceanography of the region, a reconnaissance survey was carried out to obtain baseline data on hydrographic, nutrient and sediment characteristics of shelf waters and sediments. It is expected that the data presented herein will form part of the environmental assessment for development in, and conservation of, the region and serve as a basis for designing more detailed and focused water quality surveys

    TRANSMIT: Training Research and Applications Network to Support the Mitigation of Ionospheric Threats

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    TRANSMIT is an initiative funded by the European Commission through a Marie Curie Initial Training Network (ITN). Main aim of such networks is to improve the career perspectives of researchers who are in the first five years of their research career in both public and private sectors. In particular TRANSMIT will provide a coordinated program of academic and industrial training, focused on atmospheric phenomena that can significantly impair a wide range of systems and applications that are at the core of several activities embedded in our daily life. TRANSMIT deals with the harmful effects of the ionosphere on these systems, which will become increasingly significant as we approach the next solar maximum, predicted for 2013. Main aim of the project is to develop real time integrated state of the art tools to mitigate ionospheric threats to Global Navigation Satellite Systems (GNSS) and several related applications, such as civil aviation, marine navigation and land transportation. The project will provide Europe with the next generation of researchers in this field, equipping them with skills developed through a comprehensive and coordinated training program. Theirs research projects will develop real time integrated state of the art tools to mitigate these ionospheric threats to GNSS and several applications that rely on these systems. The main threat to the reliable and safe operation of GNSS is the variable propagation conditions encountered by GNSS signals as they pass through the ionosphere. At a COST 296 MIERS (Mitigation of Ionospheric Effects on Radio Systems) workshop held at the University of Nottingham in 2008, the establishment of a sophisticated Ionospheric Perturbation Detection and Monitoring (IPDM) network (http://ipdm.nottingham.ac.uk/) was proposed by European experts and supported by the European Space Agency (ESA) as the way forward to deliver the state of the art to protect the range of essential systems vulnerable to these ionospheric threats. Through a set of carefully designed research work packages TRANSMIT will be the enabler of the IPDM network. The goal of TRANSMIT is therefore to provide a concerted training programme including taught courses, research training projects, secondments at the leading European institutions, and a set of network wide events, with summer schools, workshops and a conference, which will arm the researchers of tomorrow with the necessary skills and knowledge to set up and run the proposed service. TRANSMIT will count on an exceptional set of partners, encompassing both academia and end users, including the aerospace and satellite communications sectors, as well as GNSS system designers and service providers, major user operators and receiver manufacturers. TRANSMIT's objectives are: A. Develop new techniques to detect and monitor ionospheric threats, with the introduction of new prediction and forecasting models, mitigation tools and improved system design; B. Advance the physical modeling of the underlying processes associated with the ionospheric plasma environment and the knowledge of its influences on human activity; C. Establish a prototype of a real time system to monitor the ionosphere, capable of providing useful assistance to users, which exploits all available resources and adds value for European services and products; D. Incorporate solutions to this system that respond to all end user needs and that are applicable in all geographical regions of European interest (polar, high and mid-latitudes, equatorial region). TRANSMIT will pave the way to establish in Europe a system capable of mitigating ionospheric threats on GNSS signals in real tim

    Dissolved and particulate nutrients in waters of the Whitsunday Island Group 1988

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    This report summarizes the results of hydrographic sampling of physical properties and nutrient determinations made on water samples and water column particulate matter collected in February. 1988 during an oceanographic survey through the Whitsunday Island group. The survey was carried out to obtain background data on concentrations of chlorophyll, organic and inorganic nitrogen (N). phosphorus (P), and inorganic silicate (Si) in waters of the Whitsunday Island group. For comparative purposes, hydrographic and nutrient data from ten stations occupied in inter-reefal and lagoonal waters of the central and southern GBR during January. 1987 and February, 1988 are also presented

    The Effect of Including eHealth in Dietary Interventions for Patients with Type 2 Diabetes with Overweight or Obesity:A Systematic Review

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    eHealth has a growing impact on the delivery of healthcare, making health systems more efficient. This study examined the effect of dietary interventions using eHealth compared to face-to-face contact in patients with (pre-) type 2 diabetes (T2D) and who are overweight/obese. Literature databases were searched upon November 2022. Inclusion criteria: randomized controlled trial; duration ≥ 6 months; involving dietary interventions; performed in adults with (pre-) T2D and who are overweight/obese; using eHealth compared to face-to-face contact; and report outcomes on weight loss, glycemic regulation, and/or cost-effectiveness. Selection of articles was performed manually and using ASReviewLab. Fifteen studies were included for data extraction, investigating a wide variety of eHealth interventions. Seven studies reporting on weight loss showed a significant between-group difference (−1.18 to −5.5 kg); five studies showed a trend in favor of the eHealth programs. Eleven studies reported on HbA1c; three found a significant between-group difference (−0.23 to −0.70%) in favor of the eHealth programs and six studies showed non-significant improvements. Interaction with healthcare professionals led to better results of the dietary interventions. Two studies reported incomplete data on cost-effectiveness. In conclusion, eHealth shows better results of dietary interventions in (pre-) T2D patients compared to face-to-face, especially when combined with interaction with healthcare professionals.</p

    Extracting the rho-omega mixing amplitude from the pion form-factor

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    We re-examine and extend a recent analysis which showed that the rho-omega mixing amplitude cannot be unambiguously extracted from the pion electromagnetic form-factor in a model independent way. In particular, we focus on the argument that the extraction is sensitive to the presence of any intrinsic omega_I -> 2pi coupling. Our extended analysis confirms the original conclusion, with only minor, quantitative differences. The extracted mixing amplitude is shown to be sensitive to both the intrinsic coupling omega_I -> 2pi and to the value assumed for the mass of the neutral rho meson.Comment: 11 pages, publication details added to title pag

    Isospin-Violating Meson-Nucleon Vertices as an Alternate Mechanism of Charge-Symmetry Breaking

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    We compute isospin-violating meson-nucleon coupling constants and their consequent charge-symmetry-breaking nucleon-nucleon potentials. The couplings result from evaluating matrix elements of quark currents between nucleon states in a nonrelativistic constituent quark model; the isospin violations arise from the difference in the up and down constituent quark masses. We find, in particular, that isospin violation in the omega-meson--nucleon vertex dominates the class IV CSB potential obtained from these considerations. We evaluate the resulting spin-singlet--triplet mixing angles, the quantities germane to the difference of neutron and proton analyzing powers measured in elastic np\vec{n}-\vec{p} scattering, and find them commensurate to those computed originally using the on-shell value of the ρ\rho-ω\omega mixing amplitude. The use of the on-shell ρ\rho-ω\omega mixing amplitude at q2=0q^2=0 has been called into question; rather, the amplitude is zero in a wide class of models. Our model possesses no contribution from ρ\rho-ω\omega mixing at q2=0q^2=0, and we find that omega-meson exchange suffices to explain the measured npn-p analyzing power difference~at~183 MeV.Comment: 20 pages, revtex, 3 uuencoded PostScript figure

    Rho-omega Mixing and the Pion Electromagnetic Form-Factor

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    The suggestion of momentum dependence in the amplitude for rho-omega mixing has generated concern over related implications for vector meson dominance and the photon-rho coupling. We discuss two established representations of vector meson dominance and show that one of these is completely consistent with such a coupling. We then apply it to a calculation of the pion electromagnetic form-factor. Our analysis leads to a new value for the on-shell rho-omega mixing amplitude of (-3800 +/- 370) MeV^2.Comment: 11 pages with epsfig.sty. Publication details added to title pag
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