2,680 research outputs found
A comparison of Charolais and beef X Friesian suckler cows.
End of Project ReportThe studies carried out included comparisons of Charolais and
Beef x Friesian suckler cows in terms of voluntary silage intake,
colostrum yield and immunoglobulin level, calf immunoglobulin level
and cow milk yield in addition to animal production experiments.
In all experiments the Charolais animals used were a minimum of
7/8 Charolais and were the result of an upgrading programme at
Grange commencing with Charolais x Friesians. In the production
experiments, only Hereford x Friesian cows (and their progeny)
were compared with the Charolais while in all other experiments
the Beef x Friesians included both Hereford x Friesians and
Limousin x Friesians.European
Union Structural Funds (EAGGF
Production of red veal for the EU market.
End of Project ReportA summary of four experiments which used Holstein/Friesian bulls
and a fifth which used continental cross bulls to determine the
effect of feeding ad libitum concentrates on animal prefomance.
• The Barley soyabean meal ration provided consistent liveweight
gain (1.25 kg/day) and similar cold carcass weight (237 kg) in all
four experiments using Holstein and Friesian Bulls.
• The Low energy treatment group (Experiment 1) had a liveweight
gain of 1.14 kg/day and a cold carcass of 220 kg, i.e. 21 kg lower
than that achieved on the High energy treatment group which had
a liveweight gain of 1.26 kg/day and a cold carcass of 241 kg.
• Providing animals with a summer period outdoors at pasture compared
with a continuous period indoors, in general had the effect
of improving daily liveweight gain and feed conversion efficiency
when animals were offered ad libitum concentrate diet. The effect
was greatest when autumn-born calves spent the final 180 days
prior to slaughter at pasture.
• Restricting the concentrate allowance at pasture brought about a
1.5 unit improvement in FCR carcass, however, at a similar slaughter
age this treatment group produced carcasses that were 22 and
21 kg lighter than the control in two respective experiments.
• The current economic climate for beef production does not permit
the production of red veal in Ireland. However, when markets
develop in the Mediterranean countries there will be opportunities
to produce red veal carcasses for those markets using male bulls
from the Holstein/Friesian herds.
• Weaned continental cross suckler bulls slaughtered off an ad libitum
concentrate diet at 550 kg liveweight had a feed conversion
efficiency of 8.2 kg concentrate DM per kg carcass produced. The
corresponding value at 650 kg slaughter, liveweight was 9.5 kg.European Union Structural Funds (EAGGF
Quality Suckler Beef From Low and High Input Grassland Management Systems
End of Project ReportSpring calving cows were used in the years 1997 to 2003 in the
development of planned low and high input systems of suckler beef
production.The main objective of the study was to compare a semiintensive
Grange (standard): system of suckler beef production with
a more extensive REPS (Rural Environment Protection Scheme) compatible
system. In the standard system the stocking rate was 0.80 ha
per cow unit (cow plus heifer and steer progeny to slaughter at 20
and 23/24 months of age, respectively, plus replacements or its equivalent),
a nitrogenous fertiliser application rate of 210 kg per ha and
two silage harvests each year amounting to the equivalent of 87% of
the total area harvested. The REPS system involved a 25% lower
stocking rate, an annual nitrogen fertiliser application rate of 90 to
100 kg per ha and one silage harvest (portion in late May to provide
good silage for the progeny and the remainder in June to provide
lower quality silage for cows) amounting to 58% of the total area
harvested.
Between 1997 and 2000 the cow herd were Limousin x Friesians
(LF) and Simmental x (Limousin x Friesians) (SLF). A herd of first
calvers were introduced in 2001 and 2002 which in addition to LF
and SLF included Limousin x (Limousin x Friesians), purebred
Limousin and purebred Charolais. Charolais (or Simmental) sires
were used on mature cows. Replacement heifers were bred to calve
at 2 years of age using an easy calving Limousin bull. Concentrate
inputs per animal were the same in the two systems.
The main findings of the study were:
• The mean nitrogenous application rates were 210 and 98 kg
per ha in the standard and REPS systems, respectively.
• Mean dry matter digestibility of the first-cut silages harvested
early (May 19 to May 29), late (June 5 to June 13) and the
second cut silage in the standard system (harvested in
July/early August) were 716, 690 and 674 g/kg, respectively.
• When averaged throughout two grazing seasons there was no difference between the standard and REPS systems in pregrazing
or post-grazing sward heights.
When examined over one grazing season the only major
difference between the grazing areas was that the pasture
crude protein content was higher in the standard system in
both the pre-grazed (205 and 159 g/kg) and post-grazed (172
v 141 g/kg) swards.
Cow liveweight and body condition score gains at pasture
and calf gains from birth to weaning were the same for both
systems.
Carcass weights of the progeny were the same for the standard
and REPS systems
Efficient AUV Navigation Fusing Acoustic Ranging and Side-scan Sonar
This paper presents an on-line nonlinear least
squares algorithm for multi-sensor autonomous underwater
vehicle (AUV) navigation. The approach integrates the global
constraints of range to and GPS position of a surface vehicle
or buoy communicated via acoustic modems and relative pose
constraints arising from targets detected in side-scan sonar images.
The approach utilizes an efficient optimization algorithm,
iSAM, which allows for consistent on-line estimation of the
entire set of trajectory constraints. The optimized trajectory
can then be used to more accurately navigate the AUV, to
extend mission duration, and to avoid GPS surfacing. As iSAM
provides efficient access to the marginal covariances of previously
observed features, automatic data association is greatly
simplified — particularly in sparse marine environments. A
key feature of our approach is its intended scalability to
single surface sensor (a vehicle or buoy) broadcasting its GPS
position and simultaneous one-way travel time range (OWTT)
to multiple AUVs. We discuss why our approach is scalable
as well as robust to modem transmission failure. Results are
provided for an ocean experiment using a Hydroid REMUS
100 AUV co-operating with one of two craft: an autonomous
surface vehicle (ASV) and a manned support vessel. During
these experiments the ranging portion of the algorithm ran online
on-board the AUV. Extension of the paradigm to multiple
missions via the optimization of successive survey missions (and
the resultant sonar mosaics) is also demonstrated.United States. Office of Naval Research (Grant N000140711102
Kintinuous: Spatially Extended KinectFusion
In this paper we present an extension to the KinectFusion algorithm that permits dense mesh-based mapping of extended scale environments in real-time. This is achieved through (i) altering the original algorithm such that the region of space being mapped by the KinectFusion algorithm can vary dynamically, (ii) extracting a dense point cloud from the regions that leave the KinectFusion volume due to this variation, and, (iii) incrementally adding the resulting points to a triangular mesh representation of the environment. The system is implemented as a set of hierarchical multi-threaded components which are capable of operating in real-time. The architecture facilitates the creation and integration of new modules with minimal impact on the performance on the dense volume tracking and surface reconstruction modules. We provide experimental results demonstrating the system's ability to map areas considerably beyond the scale of the original KinectFusion algorithm including a two story apartment and an extended sequence taken from a car at night. In order to overcome failure of the iterative closest point (ICP) based odometry in areas of low geometric features we have evaluated the Fast Odometry from Vision (FOVIS) system as an alternative. We provide a comparison between the two approaches where we show a trade off between the reduced drift of the visual odometry approach and the higher local mesh quality of the ICP-based approach. Finally we present ongoing work on incorporating full simultaneous localisation and mapping (SLAM) pose-graph optimisation
Health-related quality of life and survival in liver transplant candidates.
Health-related quality of life (HRQOL) is an important measure of the effects of chronic liver disease in affected patients that helps guide interventions to improve well-being. However, the relationship between HRQOL and survival in liver transplant candidates remains unclear. We examined whether the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores from the Short Form 36 (SF-36) Health Survey were associated with survival in liver transplant candidates. We administered the SF-36 questionnaire (version 2.0) to patients in the Pulmonary Vascular Complications of Liver Disease study, a multicenter prospective cohort of patients evaluated for liver transplantation in 7 academic centers in the United States between 2003 and 2006. Cox proportional hazards models were used with death as the primary outcome and adjustment for liver transplantation as a time-varying covariate. The mean age of the 252 participants was 54 +/- 10 years, 64% were male, and 94% were white. During the 422 person years of follow-up, 147 patients (58%) were listed, 75 patients (30%) underwent transplantation, 49 patients (19%) died, and 3 patients were lost to follow-up. Lower baseline PCS scores were associated with an increased mortality rate despite adjustments for age, gender, Model for End-Stage Liver Disease score, and liver transplantation (P for the trend = 0.0001). The MCS score was not associated with mortality (P for the trend = 0.53). In conclusion, PCS significantly predicts survival in liver transplant candidates, and interventions directed toward improving the physical status may be helpful in improving outcomes in liver transplant candidates
A Probabilistic Deformation Demand Model and Fragility Estimates for Asymmetric Offshore Jacket Platforms
Interest in evaluating the performance and safety of offshore oil and gas platforms has been expanding due to the growing world energy supply and recent offshore catastrophes. In order to accurately assess the reliability of an offshore platform, all relevant uncertainties must be properly accounted for. This necessitates the development of a probabilistic demand model that accounts for the relevant uncertainties and model errors.
In this study, a probabilistic demand model is developed to assess the deformation demand on asymmetric offshore jacket platforms subject to wave and current loadings. The probabilistic model is constructed by adding correction terms and a model error to an existing deterministic deformation demand model. The correction terms are developed to capture the bias inherent in the deterministic model. The model error is developed to capture the accuracy of the model. The correction terms and model errors are estimated through a Bayesian approach using simulation data obtained from detailed dynamic analyses of a set of representative asymmetric offshore platform configurations. The proposed demand model provides accurate and unbiased estimates of the deformation demand on offshore jacket platforms.
The developed probabilistic demand model is then used to assess the reliability of a typical offshore platform considering serviceability and ultimate performance levels. In addition, a sensitivity analysis is conducted to assess the effect of key parameters on the results of the analyses. The proposed demand model can be used to assess the reliability of different design options and for the reliability-based optimal design of offshore jacket platforms
Polyamines in cell culture
Described is an investigation into the role of polyamines in plant cells. The study was performed throughout with the use of a liquid suspension culture of carrot (Daucus carota cv Chantenay) cells as the model system. Polyamine synthesis and accumulation were studied during the culture growth period, with biosynthetic and catabolic enzyme assays performed to determine rates of polyamine synthesis and free-polyamine analysis to determine cellular polyamine levels. Methods of manipulating polyamine levels within the cell were studied. These included varying the constituents of the growth medium of the suspension culture, such as the plant hormone levels and the balance and level of the available nitrogen sources. The possibility that polyamine supplements might replace plant hormones in the growth medium was investigated and polyamine precursors were added to the medium in an attempt to boost cellular polyamine levels. A substantial comparative study was also made into the effects of inhibitors of polyamine biosynthesis on polyamine biosynthesis and accumulation. Included were determinations of the effects of a range of inhibitors on polyamine biosynthetic and catabolic enzyme activities, on the accumulation of polyamines within the cell and on growth over the culture period. Finally, the relationship between polyamines and other solutes, and cellular responses to short and long-term stress conditions was studied - both in cells previously adapted to stress conditions, and unadapted cell lines. Principal findings were: a) Difluoromethylarginine strongly inhibits arginine decarboxylase and radically reduces putrescine and total amine content, while having no effect on cell number and stimulating fresh weight through increased cell expansion. b) Difluoromethylornithine strongly inhibits ornithine decarboxylase activity but has little effect on either polyamine levels or culture growth. c) Ethylmethylglyoxalbisguanylhydrazone strongly inhibits S- adenosylmethionine decarboxylase activity with little effect on fresh weight. d) Proline and other organic solutes increase in concentration in response to polyethylene glycol induced water stress in adapted and unadapted cell lines while polyamines and glycinebetaine do not increase significantly
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Meeting Report: Methylmercury in Marine Ecosystems—From Sources to Seafood Consumers
Mercury and other contaminants in coastal and open-ocean ecosystems are an issue of great concern globally and in the United States, where consumption of marine fish and shellfish is a major route of human exposure to methylmercury (MeHg). A recent National Institute of Environmental Health Sciences–Superfund Basic Research Program workshop titled “Fate and Bioavailability of Mercury in Aquatic Ecosystems and Effects on Human Exposure,” convened by the Dartmouth Toxic Metals Research Program on 15–16 November 2006 in Durham, New Hampshire, brought together human health experts, marine scientists, and ecotoxicologists to encourage cross-disciplinary discussion between ecosystem and human health scientists and to articulate research and monitoring priorities to better understand how marine food webs have become contaminated with MeHg. Although human health effects of Hg contamination were a major theme, the workshop also explored effects on marine biota. The workgroup focused on three major topics: a) the biogeochemical cycling of Hg in marine ecosystems, b) the trophic transfer and bioaccumulation of MeHg in marine food webs, and c) human exposure to Hg from marine fish and shellfish consumption. The group concluded that current understanding of Hg in marine ecosystems across a range of habitats, chemical conditions, and ocean basins is severely data limited. An integrated research and monitoring program is needed to link the processes and mechanisms of MeHg production, bioaccumulation, and transfer with MeHg exposure in humans
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