562 research outputs found

    Farm-gate phosphorus balances and soil phosphorus concentrations on intensive dairy farms in the south-west of Ireland

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    peer-reviewedThis project was part funded by the European Research and Development Fund under INTERREG IIIB: Green Dairy Project Number 100 and partly by the Dairy Levy. Financial support for post-graduate students involved in this study was provided by the Teagasc Walsh Fellowship Scheme.Phosphorus (P) loss to water is a significant threat to water quality in Ireland. Agriculture is an important source of this P. There is concern about balancing agronomic requirements and environmental protection in regulations prescribing P management on farms. This study examined farm-gate (P) balances and soil test P (STP) concentrations on 21 dairy farms in the south west of Ireland over four years, from 2003 to 2006 inclusive. Stocking density on the farms averaged 2.4 (s.d. = 0.4) livestock units (LU) per ha. Annual mean import of P onto farms was 21.6 (1.9) kg P/ha. Fertilizer P accounted for 47% (0.041), concentrates 35% (0.060) and organic manures 18% (0.034) of imported P. The mean annual P balance per farm was 9.4 (1.2) kg/ha, ranging from –3 to 47 kg/ha and mean P use efficiency was 0.71 (0.05) ranging from 0.24 to 1.37. The mean STP per farm following extraction using Morgan’s solution was 8.15 (2.9) mg/L of soil and ranged from 4.4 (2.2) to 14.7 (6.4) mg/L. There was a positive relationship (R2 = 0.34; P < 0.01) between STP and P balance; farms with a deficit of P tended to have agronomically sub-optimal STP and vice versa. The high between- and withinfarm variation in STP indicates that farmers were either unaware or were not making efficient use of STP results, and consequently there was agronomically sub-optimal soil P status in some fields and potentially environmentally damaging excesses on others (often within one farm). There was considerable potential to improve P management practices on these farms with clear agronomic and environmental benefits.European UnionTeagasc Walsh Fellowship ProgrammeDairy Levy Fun

    Fish Health Unit Report of Activities Undertaken in 2018 and 2019

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    This report summarises the activities undertaken by the Fish Health Unit (FHU) of the Marine Institute (MI) in 2018 and 2019. The services of the FHU, undertaken on behalf of the State, are largely driven by European and national legislation on aquatic animal health. European Council Directive 2006/88/EC on animal health requirements for aquaculture animals lays down rules for the control of aquatic animal health within the EU. The directive is enacted in Irish Law by Statutory Instrument (SI) 261 of 2008. The MI is the Competent Authority (CA) responsible for implementation of aquatic animal health regulation in Ireland as described in these statutes. Aquatic animal health regulations in SI 261 of 2008 apply to finfish farms, shellfish farms, and put and take fisheries, and require that such aquaculture production businesses (APBs) obtain a Fish Health Authorisation (FHA) from the CA prior to operation

    A Mach-Zehnder interferometer based on orbital angular momentum for improved vortex coronagraph efficiency

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    The Annular Groove Phase Mask (AGPM) is a vectorial vortex phase mask. It acts as a half-wave plate with a radial fast axis orientation operating in the mid infrared domain. When placed at the focus of a telescope element provides a continuous helical phase ramp for an on axis sources, which creates the orbital angular momentum. Thanks to that phase, the intensity of the central source is canceled by a down-stream pupil stop, while the off axis sources are not affected. However due to experimental conditions the nulling is hardly perfect. To improve the null, a Mach-Zehnder interferometer containing Dove prisms differently oriented can be proposed to sort out light based on its orbital angular momentum (OAM). Thanks to the differential rotation of the beam, a π phase shift is achieved for the on axis light affected by a non zero OAM. Therefore the contrast between the star and its faint companion is enhanced. Nevertheless, due the Dove prisms birefringence, the performance of the interferometer is relatively poor. To solve this problem, we propose to add a birefringent wave-plate in each arm to compensate this birefringence. In this paper, we will develop the mathematical model of the wave front using the Jones formalism. The performance of the interferometer is at first computed for the simple version without the birefringent plate. Then the effect of the birefringent plate is be mathematically described and the performance is re-computed

    Review of high-contrast imaging systems for current and future ground- and space-based telescopes I. Coronagraph design methods and optical performance metrics

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    The Optimal Optical Coronagraph (OOC) Workshop at the Lorentz Center in September 2017 in Leiden, the Netherlands gathered a diverse group of 25 researchers working on exoplanet instrumentation to stimulate the emergence and sharing of new ideas. In this first installment of a series of three papers summarizing the outcomes of the OOC workshop, we present an overview of design methods and optical performance metrics developed for coronagraph instruments. The design and optimization of coronagraphs for future telescopes has progressed rapidly over the past several years in the context of space mission studies for Exo-C, WFIRST, HabEx, and LUVOIR as well as ground-based telescopes. Design tools have been developed at several institutions to optimize a variety of coronagraph mask types. We aim to give a broad overview of the approaches used, examples of their utility, and provide the optimization tools to the community. Though it is clear that the basic function of coronagraphs is to suppress starlight while maintaining light from off-axis sources, our community lacks a general set of standard performance metrics that apply to both detecting and characterizing exoplanets. The attendees of the OOC workshop agreed that it would benefit our community to clearly define quantities for comparing the performance of coronagraph designs and systems. Therefore, we also present a set of metrics that may be applied to theoretical designs, testbeds, and deployed instruments. We show how these quantities may be used to easily relate the basic properties of the optical instrument to the detection significance of the given point source in the presence of realistic noise.Comment: To appear in Proceedings of the SPIE, vol. 1069

    Investigating the Psychological Impact of Active Surveillance or Active Treatment in Newly Diagnosed Favorable-Risk Prostate Cancer Patients: A 9 month Longitudinal Study

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    Objective This study aimed to explorethe psychological impact of favorable-risk prostate cancer (PCa) and associated treatment (Active Surveillance (AS) or Active Treatment (AT)), comparing prevalence and temporal variability of generalized anxiety, PCa-specific anxiety, and depression symptoms. Methods PCa patients were recruited at diagnosis prior to treatment decision-making and completed questionnaires assessing anxiety (STAI-6; MAX-PC) and depression symptoms (CES-D) at four timepoints for 9-months. Non-cancer controls were recruited via university staff lists and community groups. Results were analyzed using analysis of variance. Results Fifty-four PCa (AS n=11, AT n=43) and fifty-three non-cancer participants were recruited. The main effect of time or treatment group were not statistically significant for CES-D scores (p>0.05). The main effect of treatment on STAI-6 scores was significant (F(2,73)=4.678, p=0.012) with AS patients reporting highest STAI-6 scores (T1 M=36.56; T2 M=36.89, T3 M=38.46; T4 M=38.89). There was a significant main effect for time since diagnosis on MAX-PC (F(3,123)=3.68, p=0.01), AS patient scored higher than AT at all timepoints (T1 M=10.33 v 10.78; T2 M=11.11 v 11.30; T3 M=13.44 v 10.55; T4 M=11.33 v 8.88), however both groups declined overall with time. Conclusions Men undergoing AS had significantly higher anxiety symptoms than AT and non-cancer participants, contradicting previous literature. This may be due to perceived inactivity of AS relative to traditional narratives of cancer treatment. Participant experiences appear to be less favorable relative to other international centers. Recommendations for future research and clinical practice include the need to improve diagnosis and treatment information provision particularly for lower-risk patients

    An index to quantify an individual's scientific research output that takes into account the effect of multiple coauthorship

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    I propose the index \hbar ("hbar"), defined as the number of papers of an individual that have citation count larger than or equal to the \hbar of all coauthors of each paper, as a useful index to characterize the scientific output of a researcher that takes into account the effect of multiple coauthorship. The bar is higher for \hbar.Comment: A few minor changes from v1. To be published in Scientometric

    Reclaiming the political : emancipation and critique in security studies

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    The critical security studies literature has been marked by a shared commitment towards the politicization of security – that is, the analysis of its assumptions, implications and the practices through which it is (re)produced. In recent years, however, politicization has been accompanied by a tendency to conceive security as connected with a logic of exclusion, totalization and even violence. This has resulted in an imbalanced politicization that weakens critique. Seeking to tackle this situation, the present article engages with contributions that have advanced emancipatory versions of security. Starting with, but going beyond, the so-called Aberystwyth School of security studies, the argument reconsiders the meaning of security as emancipation by making the case for a systematic engagement with the notions of reality and power. This revised version of security as emancipation strengthens critique by addressing political dimensions that have been underplayed in the critical security literature

    Utilizing active single-mode fiber injection for speckle nulling in exoplanet characterization

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    Despite recent advances in high-contrast imaging techniques, high resolution spectroscopy for characterization of exoplanet atmospheres is still limited by our ability to suppress residual starlight speckles at the planet’s location. We have demonstrated a new concept for speckle nulling by injecting directly imaged planet light into a single-mode fiber, linking a high-contrast adaptively-corrected coronagraph to a high-resolution spectrograph (diffraction-limited or not). The restrictions on the incident electric field that will couple into the single-mode fiber give the adaptive optics system additional degrees of freedom to suppress the speckle noise on top of destructive interference. We are able to achieve a starlight suppression gains that are an order of magnitude better than conventional techniques in broadband light with minimal planet throughput losses
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