1,539 research outputs found

    The role of clover in organic milk production

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    Relatively high levels of milk output are possible from organic clover-based grassland compared with average production on conventional dairy farms in Ireland. Although clover-based swards receiving no fertilizer have relatively low growth in spring, a long grazing season can be achieved by extending the grazing season during the autumn and winter. High growth rates during the summer and autumn and relatively low stocking densities on organic dairy farms facilitate this. Maintaining the clover content of swards is important to maintain productivity. Tight grazing to 4 cm throughout the year and particularly during the late autumn and winter is important. Identifying swards with declining clover contents due to competition from the grass component of the sward or due to hoof damage is also important. These swards need to be over- sown the following year with the target of over-sowing or re-seeding no less than 20% of the farm each year

    Comparison of milk production from clover-based and fertilizer-N-based grassland

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    peer-reviewedFunding for this study was provided by the Irish National Development Plan and the Irish Dairy Levy.This study, conducted over four years (2003–2006), compared herbage production, nutritive value of herbage, the length of the grazing season and milk production per cow and per hectare from grassland systems based on (i) white clover (average 219 g/kg of herbage DM) (WC) receiving on average N application of 90 kg/ha (s.d. 6.4) in spring and successive 0.2 of the area over-seeded annually with white clover seed and (ii) fertilizer N (FN) input of 226 kg/ha (s.d. 9.7). The stocking density of Holstein- Friesian dairy cows on both systems was 2.0/ha 2003 and 2.2/ha in each of the following three years. There were 22 cows per system in 2003 and 24 cows per system in each of the following three years. Cows calved within a 12 week interval in spring with mean calving date in mid-February. Milk was produced until mid-December each year. Total annual herbage DM production was lower (P 0.05) differences in the in vitro organic matter digestibilities of pre-grazing herbage. The crude protein concentration in pre-grazing herbage DM was higher (P 0.05) differences in annual production of milk per cow (mean 6524 kg; s.e. 83.9 kg), live-weight or body condition score between the two systems. There were no (P < 0.05) differences in the lengths of the grazing season, which averaged 254 days (s.e. 0.9). Although there was no difference in performance per cow, the higher herbage production indicates that a higher stocking rate and milk output per hectare was possible from FN than WC. Nevertheless, the WC swards supported an annual stocking density of 2.15/ha and a milk output of 14 t/ha.National Development PlanIrish Dairy Levy Research Fun

    Multiple object tracking using a neural cost function

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    This paper presents a new approach to the tracking of multiple objects in CCTV surveillance using a combination of simple neural cost functions based on Self-Organizing Maps, and a greedy assignment algorithm. Using a reference standard data set and an exhaustive search algorithm for benchmarking, we show that the cost function plays the most significant role in realizing high levels of performance. The neural cost function’s context-sensitive treatment of appearance, change of appearance and trajectory yield better tracking than a simple, explicitly designed cost function. The algorithm matches 98.8% of objects to within 15 pixels

    The structure of the accretion disk in NGC 4258 derived from observations of its water vapor masers

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    A wealth of new information about the structure of the maser disk in NGC 4258 has been obtained from a series of 18 VLBA observations spanning three years, as well as from 32 additional epochs of spectral monitoring data from 1994 to the present, acquired with the VLA, Effelsberg, and GBT. The warp of the disk has been defined precisely. The thickness of the maser disk has been measured to be 12 microarcseconds (FWHM), which is slightly smaller than previously quoted upper limits. Under the assumption that the masers trace the true vertical distribution of material in the disk, from the condition of hydrostatic equilibrium the sound speed is 1.5 km/s, corresponding to a thermal temperature of 600K. The accelerations of the high velocity maser components have been accurately measured for many features on both the blue and red side of the spectrum. The azimuthal offsets of these masers from the midline (the line through the disk in the plane of the sky) and derived projected offsets from the midline based on the warp model correspond well with the measured offsets. This result suggests that the masers are well described as discrete clumps of masing gas, which accurately trace the Keplerian motion of the disk. However, we have continued to search for evidence of apparent motions caused by ``phase effects.'' This work provides the foundation for refining the estimate of the distance to NGC 4258 through measurements of feature acceleration and proper motion. The refined estimate of this distance is expected to be announced in the near future.Comment: 8 pages, 5 figures, to appear in proceedings of IAU Symposium 242 "Astrophysical Masers and their Environments", held in Alice Springs, March 200

    Development Assistance, Institution Building, and Social Cohesion after Civil War: Evidence from a Field Experiment in Liberia

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    Can brief, foreign-funded efforts to build local institutions have positive effects on local patterns of governance, cooperation, and well-being? Prior research suggests that such small-scale, externally driven interventions are unlikely to substantially alter patterns of social interaction in a community, and that the ability of a community to act collectively is the result of a slow and necessarily indigenous process. We address this question using a randomized field experiment to assess the effects of a community-driven reconstruction (CDR) project carried out by the International Rescue Committee (IRC) in northern Liberia. The project attempted to build democratic, community-level institutions for making and implementing decisions about local public goods. We find powerful evidence that the program was successful in increasing social cohesion, some evidence that it reinforced democratic political attitudes and increased confidence in local decision-making procedures, but only weak evidence that material well-being was positively affected. There is essentially no evidence of adverse effects.Liberia; reconstruction; post-conflict; institution building; democracy; development; peacebuilding

    A Q-methodology study of patients' subjective experiences of TIA

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    Background. An expanding body of research has focused on a range of consequences of TIA. However, no work has been conducted on the patient’s subjective experience of TIA. Aim. To capture patients’ first-hand experiences of TIA. Method. Using Q-methodology which employs both qualitative and quantitative approaches, 39 statements relating to the clinical, physical, affective, and psychological impact of TIA were distilled from the literature and from patient narratives. Consistent with conventional Q-methodology, a purposive sample of twentythree post-TIA patients sorted these statements into a normally-distributed 39-cell grid, according to the extent to which each represented their experience of TIA. Results. Casewise factoranalysis was conducted on the sorted statements. Eight factors emerged which were labelled: lack of knowledge/awareness of TIA; life impact; anxiety; interpersonal impact; depression; physical consequences; cognitive avoidance/denial; constructive optimism. Conclusions. Five of the eight factors confirmed existing research on the impact of TIA, but three new issues emerged: deep-seated anxiety, denial and constructive optimism. The emerging perspectives highlight areas to target in the management of TIA and could inform health education messages, patient information, individualised caremanagement, and enhancement of coping strategies. With development, the findings could be used as a basis for psychometric risk assessment of TIA patients

    The Struggle for Equality: Essays on Sectional Conflict, the Civil War, and the Long Reconstruction

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    A Collection of Essays in Tribute to a Great Historian Eighteen former students of the historian James M. McPherson contributed chapters to this Festschrift for their renowned mentor. Few scholars are as deserving as McPherson of such an honor. A historian of Abraham Lincoln, an ...

    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
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