Geometrical considerations in the separation of biological particles by affinity partitioning

A theoretical description of the affinity partitioning effect is presented. Experiments at reduced and zero g are discussed

Effects of extended grazing during mid, late or throughout pregnancy, and winter shearing of housed ewes, on ewe and lamb performance

peer-reviewedA flock of March-lambing ewes was used to evaluate the effects of (i) extended (deferred, winter) grazing of pasture during mid, late or throughout pregnancy, and (ii) winter shearing of ewes housed during mid and late pregnancy, on lamb birth weight and subsequent growth to weaning. Ewes (n = 265) were allocated at random to five treatments for the period from 7 December (~ day 47 of pregnancy) to lambing. The treatments were: housed shorn (HS), housed unshorn (HU), grazing throughout (EG), grazing to 20 January followed by housing (EGH), housed to 20 January followed by grazing (HEG). From 1 March to lambing the HEG and EG ewes were dispersed on the paddocks intended for grazing post lambing. All ewes were offered a concentrate supplement during the final 6 weeks of pregnancy. Housed ewes were offered grass silage while ewes on extended grazing were allocated 1.3 kg herbage dry matter per head per day from swards that had been closed for approximately 10 weeks. Ewes plus lambs (except triplet-rearing ewes which were grazed separately) from all treatments were grazed together post lambing, grouped according to lambing date. For treatments HS, HU, EGH, HEG and EG gestation lengths were 147.0, 145.6, 146.3, 146.6 and 146.9 (s.e. 0.34, P < 0.001) days, lamb birth weights were 4.9, 4.3, 4.4, 4.6 and 5.0 (s.e. 0.10, P < 0.001) kg, and lamb weaning weights were 34.6, 32.1, 33.3, 33.8 and 34.9 (s.e. 0.66, P < 0.001) kg, respectively. Extended grazing in mid and late pregnancy resulted in 35% and 65%, respectively, of the increase in lamb birth weight associated with extended grazing throughout. Treatment effects on lamb birth weight were associated with those on weaning weight (P < 0.01, R2 = 0.93). It is concluded that extended grazing or shearing of housed ewes increased lamb birth weight and subsequent weaning weight. The increased lamb birth weight from deferred grazing in mid pregnancy was probably due to improved protein utilisation from the grazed herbage. Meanwhile, the increase

An evaluation of two grassland-based systems of mid-season prime lamb production using prolific ewes of two genotypes

peer-reviewedA 4-year study was undertaken to evaluate the effects of two contrasting management systems [year-round grazing (YRG) and normal seasonal grazing followed by indoor feeding during winter (GWF)] on performance of mid-season lambing ewes. On the GWF system, the annual stocking rate was 14.4 ewes/ha, grass silage was conserved for winter feeding indoors, and the ewes were lambed indoors and were then turned out to pasture. The YRG system was stocked at 10.5 ewes/ha, was grazed during the winter, had outdoor lambing and the animals had access to all the farmlet for summer grazing. The ewes were Belclare and Cheviot × Belclare which were balanced across systems. Mean lambing dates and fertiliser N application rates were 20 and 30 March, and 85 and 92 kg/ha, for the GWF and YRG systems, respectively. Concentrate supplementation during late pregnancy was similar on both systems. For the GWF and YRG systems, litter size, lamb mortality, number of lambs reared, birth weight (kg), weaning weight (kg) and lamb carcass output (kg/ha) were 2.17 and 2.24 (s.e. 0.038), 10.1 and 13.8% (P = 0.05), 1.77 and 1.78 (s.e. 0.042), 4.0 and 4.7 (s.e. 0.05, P < 0.001), 27.9 and 30.8 (s.e. 0.25, P < 0.001) and 469 and 348, respectively. Belclare ewes had a higher litter size (2.34 v 2.07; s.e. 0.038, P < 0.001) and number of lambs reared per ewe joined (1.86 v 1.69; s.e. 0.048, P < 0.01) than the Cheviot × Belclare ewes. There were no significant interactions between system and ewe breed type. It is concluded that the YRG system of prime lamb production was sustainable using prolific ewes but at a reduced stocking rate (−26%) and with greater lamb mortality relative to the GWF system. Ewe genotypes with a mean litter size of up to 2.34 lambs are suitable for both systems. Lamb carcass output of 501 kg/ha was achieved from a primarily grass-based system of mid-season prime lamb production using prolific ewes (Belclare)

A power filter for the detection of burst sources of gravitational radiation in interferometric detectors

We present a filter for detecting gravitational wave signals from burst sources. This filter requires only minimal advance knowledge of the expected signal: i.e. the signal's frequency band and time duration. It consists of a threshold on the total power in the data stream in the specified signal band during the specified time. This filter is optimal (in the Neyman-Pearson sense) for signal searches where only this minimal information is available.Comment: 3 pages, RevTeX, GWDAW '99 proceedings contribution, submitted to Int. J. Modern Phys.

Brane World Models With Bulk Scalar Fields

We examine several different types of five dimensional stationary spacetimes with bulk scalar fields and parallel 3-branes. We study different methods for avoiding the appearance of spacetime singularities in the bulk for models with and without cosmological expansion. For non-expanding models, we demonstrate that in general the Randall-Sundrum warp factor is recovered in the asymptotic bulk region, although elsewhere the warping may be steeper than exponential. We show that nonsingular expanding models can be constructed as long as the gradient of the bulk scalar field vanishes at zeros of the warp factor, which are then analogous to the particle horizons found in expanding models with a pure AdS bulk. Since the branes in these models are stabilized by bulk scalar fields, we expect there to be no linearly unstable radion modes. As an application, we find a specific class of expanding, stationary solutions with no singularities in the bulk in which the four dimensional cosmological constant and mass hierarchy are naturally very small.Comment: 16 page

Can superhorizon perturbations drive the acceleration of the Universe?

It has recently been suggested that the acceleration of the Universe can be explained as the backreaction effect of superhorizon perturbations using second order perturbation theory. If this mechanism is correct, it should also apply to a hypothetical, gedanken universe in which the subhorizon perturbations are absent. In such a gedanken universe it is possible to compute the deceleration parameter $q_0$ measured by comoving observers using local covariant Taylor expansions rather than using second order perturbation theory. The result indicates that second order corrections to $q_0$ are present, but shows that if $q_0$ is negative then its magnitude is constrained to be less than or of the order of the square of the peculiar velocity on Hubble scales today. We argue that since this quantity is constrained by observations to be small compared to unity, superhorizon perturbations cannot be responsible for the acceleration of the Universe.Comment: revtex, 4 pages, no figures; final published versio

Early Lamb Production Systems

End of Project ReportsA number of feeding and management options for early lambing flocks were evaluated at the Knockbeg Sheep Unit, Carlow. Results and recommendations for on-farm adoption are summarised in this report. The ultimate objective was to develop cost-effective early lamb production systems in synchrony with the high price season from late March to early May. Studies were focused on the two main phases of lamb growth. Firstly, the period from birth to 6 weeks of age which coincides with the critical period of lamb survival and peak lactation in the ewe and, secondly, the finishing stage from 6 weeks until slaughter. Flock size was 230 to 250 ewes sponged in July/August for lambing in January and managed on 12.6 ha of grass and forage. The results provide options in feeding and management for programmed lamb production in synchrony with early season prices. The production technologies are effective, e.g. out-of-season breeding, grass utilisation, planned schedules for achieving high levels of feed intake and lamb performance, drafting procedures for selecting high quality lambs (Fat class 3, Conformation classes U and R). On-farm planning for feeding, housing and labour is essential.European Union Structural Funds (EAGGF

Deep space network

Background, current status, and sites of Deep Space Network stations are briefly discussed

Maximising grazed grass in the diet of the ewe for mid-season lamb production.

End of Project ReportA trial was conducted at the Knockbeg Sheep Unit, Co. Carlow over the years 1998/99 and 1999/00 with objectives centred on maximising the role of grazed grass in the diet of the ewe by accumulating autumn pasture and carrying it forward for winter grazing. Using a farmlet system approach, two systems of mid season lamb production, intensive and extensive, were compared for ewe productivity, lamb performance, carcass output per ha and associated management inputs. The stocking rates chosen for the two systems were: (1) 13 ewes per ha including silage conservation and housing for a 100-day winter and, (2) 10 ewes per ha with extended grazing in winter

Understanding the competitiveness factors of Korean contractors in the international construction market

The international construction markets (ICM) are constantly changing with new pressures creating opportunities and threats., Enterprises from advanced major advanced economies have been successful in venturing overseas and winning projects by exploiting their design, engineering, technological, and managerial competencies. Construction markets have changed with Chinese, Japanese, Korean, and Turkish construction enterprises securing more projects overseas. Understanding and exploiting the competitive advantage possessed by enterprises from major advanced economies is being challenged by enterprises from newly industrialised economies. This study investigates the competitiveness factors of the Korean construction (KOC) enterprises to understand how they have been successful in exploiting their competitive advantages. The competitiveness evaluation model (CEM) is developed using system dynamics which compares the project performances between the models generated by general and Korea-featured competitiveness factors in winning work in the ICM. The findings reveal that ownership of the enterprise, government strategy and support for the construction industry enterprises, strong leadership, technology-intensive, and special characteristics of large Korean enterprises (Chaebol system) could be critical factors for creating competitive advantage