Large sieve inequalities with power moduli and Waring's problem

We improve the large sieve inequality with $k$th-power moduli, for all $k\ge 5$. Our method relates these inequalities to a restricted variant of Waring's problem. Firstly, we input a classical divisor bound on the number of representations of a positive integer as a sum of two $k$th-powers. Secondly, we input a recent and general result of Wooley on mean values of exponential sums. Lastly, we state a conditional result, based on the conjectural Hardy-Littlewood formula for the number of representations of a large positive integer as a sum of $k+1$ $k$th-powers.Comment: 10 page

Enhancement of pigmeat quality by altering pre-slaughter management

End of project reportThe studies presented in this report were conducted to investigate the effect of breed, slaughter weight, castration of male pigs and strategic feeding strategies on the performance of pigs to slaughter and on their carcass quality. The effect of breed, gender and feeding regimen on the performance of pigs and their carcass quality was examined in the first study (Section 3). From weaning to slaughter Landrace-sired pigs grew at a similar rate but had a better feed conversion efficiency compared with Duroc-sired pigs. Landrace-sired pigs also had a higher carcass lean and greater muscle depth than Duroc-sired pigs. Entire male pigs grew more efficiently, had lower lean content in their carcasses and had a reduced kill out yield when compared with gilts. The eye muscle depth was greater for gilts than entire males. Diluting the diet with grass-meal (GM) reduced growth rate, caused a deterioration in feed conversion efficiency, reduced back fat thickness, reduced eye muscle thickness and reduced kill out yield compared to the control feeding regimen of a cereal based diet. Compensatory growth was observed during a re-alimentation period following a period of diet dilution with grass-meal. However, where it did occur, in most cases it was only partial. Adding 5% rapeseed oil instead of lard to the finisher diet increased nitrogen utilization efficiency and phosphorous utilization efficiency. The effect of gender (boar, castrate, gilt) and slaughter weight (80 to 120kg) on pig performance, carcass quality, meat quality, and nitrogen excretion was investigated in the second study (Section 4). Boars grew faster than gilts and more efficiently than castrates or gilts. Castrates had a higher kill out yield than boars. Nitrogen excretion from castrates was similar to gilts which were both higher than that from boars. The processing value of carcasses from castrates may be higher than that of boars and gilts. In particular castrates had heavier loins and bellies than either boars or gilts. Carcasses from castrates and gilts had a higher temperature (recorded 24 hours post slaughter) than boars. However, pH24 was not affected by gender. The intramuscular fat content of the l. dorsi in castrates was higher than that of boars or gilts, however at 1.65% this was well below the level (2.0%) above which any noticeable sensory attributes might be detected. Feed intake increased with increasing slaughter weight and feed conversion efficiency deteriorated. N excretion also increased with each increment in weight. Carcass lean content increased up to 90kg live EOP 4939.doc 4 25/10/2005 weight then reached a plateau and declined after 110kg live weight. Heavier carcasses yielded more product for approximately the same slaughtering cost and the associated larger muscles could make it easier to use seam butchery techniques that result in lean, well-trimmed, attractive cuts and joints. The pH45 and pH24 were reduced with increasing slaughter weight and drip loss increased. Heavier pigs may be more prone to the development of PSE than lighter pigs as their carcass temperature remains higher for longer than that of lighter pigs

Perception visuelle du mouvement humain dans les interactions lors de tâches locomotrices

During daily activities, a walker interacts with their environment, especially the other walkers, avoiding any collision with them. The nature of visual information that is used for a collision-free interaction requires further understanding. Specifically, the thesis aims to answer the following questions: what are the visual cues an individual perceives from the movement of others? What are the possible interpretation mechanisms and models used for determining future predicted crossing distances? To answer these questions, we designed experiments considering collision avoidance interactions between two walkers in virtual reality, allowing detailed control of the visual environment and the available visual information. The first study of the thesis focused on the nature of visual information provided from another walker, investigating whether these visual cues are extracted from local body parts or from global perception of the body motion. The second study investigated the influence of the walker's path (straight or curved), which the participant is interacting with for the accurate estimation of future risk of collision. Finally, the third study investigated whether eye contact influences the interaction. Here we have demonstrated the coupling of perceived actionopportunities affordances from the nature of visual information and evidenced that walkers can detect future predicted collisions when another walker follows a path with constant acceleration.Durant ses activités quotidiennes, un marcheur interagit avec son environnement et en particulier avec les autres marcheurs, notamment en évitant toute collision. La nature de l'information visuelle utilisée pour une interaction sans collision est une question encore très ouverte à ce jour. Dans ce cadre, cette thèse vise à répondre aux questions suivantes : quels sont les indices visuels qu'un individu perçoit à partir du mouvement des autres ? Quels sont les mécanismes d'interprétation possibles et les modèles utilisés pour déterminer les possibles risques de collision ? Afin de répondre à ces questions, nous avons mis en place des expérimentations impliquant des évitements de collision entre deux marcheurs en utilisant la réalité virtuelle, permettant un contrôle détaillé de l'environnement visuel et des informations visuelles disponibles. La première étude s'est concentrée sur la nature de l'information visuelle fournie par un autre marcheur, en particulier, si ces informations sont extraites d’une perception locale considérant les segments corporels, ou d’une perception globale du mouvement du corps. La deuxième étude s'est concentrée sur l’influence de la trajectoire de l’autre marcheur (en ligne droite ou en courbe) sur la capacité à estimer de façon précise un possible risque de collision. Enfin, la troisième étude s'est concentrée sur l’effet du contact visuel sur l'interaction entre les deux marcheurs. Nous avons présenté ici le couplage entre les possibilités d'action perçues et les possibilités offertes par la nature de l'information visuelle et démontré que les marcheurs peuvent détecter les collisions futures prévues lorsqu'un autre marcheur suit une trajectoire avec des accélérations constantes

Characterisation of physiological and immunological responses in beef cows to abrupt weaning and subsequent housing

peer-reviewedBackground: Weaning involves the permanent separation of the calf from the dam and has been shown to be stressful for both. The objectives of this study were to characterise the effect of i) abrupt weaning and ii) subsequent housing on the extended physiological and immunological responses of beef cows. At weaning (day (d) 0, mean age of calf (s.d.) 212 (24.5) d), cows were abruptly separated from their calves and returned to the grazing area. After 35 d at pasture, cows were housed in a slatted floor shed and offered grass silage ad libitum plus a mineral-vitamin supplement daily. Rectal body temperature was recorded and blood samples were obtained on i) d 0 (weaning), 2, 7, 14, 21, 28, 35 and subsequently on ii) d 0 (housing), 2, 7, 14 and 21 for physiological, haematological and immunological measurements. Results: Post-weaning, concentration of cortisol and dehydroepiandrosterone were unchanged (P > 0.05). Rectal body temperature, neutrophil number and neutrophil: lymphocyte ratio increased (P 0.05). On d 2 post-housing, neutrophil number and neutrophil: lymphocyte ratio increased (P < 0.05), whereas lymphocyte number and concentrations of dehydroepiandrosterone, fibrinogen and non-esterified fatty acid decreased (P < 0.05) compared with pre-housing baseline. Concentration of haptoglobin increased (P < 0.05) on d 14 to 21 post-housing. Conclusions: A transitory increase in neutrophil number and decrease in lymphocyte number, increased neutrophil:lymphocyte ratio coupled with decreased interferon-γ production, and increased concentration of acute phase proteins indicate a stress response in cows post-weaning, whereas post-housing, changes were less marked.Teagasc Walsh Fellowship; John Hume Scholarship (E.M. Lynch

Effect of pre-weaning concentrate supplementation on peripheral distribution of leukocytes, functional activity of neutrophils, acute phase protein and behavioural responses of abruptly weaned and housed beef calves

<p>Abstract</p> <p>Background</p> <p>The effect of pre-weaning concentrate supplementation on peripheral distribution of leukocytes, functional activity of neutrophils, acute phase protein response, metabolic and behavioural response, and performance of abruptly weaned and housed beef calves was investigated. Calves were grazed with their dams until the end of the grazing season when they were weaned and housed (day (d) 0) in a concrete slatted floor shed, and offered grass silage <it>ad libitum </it>plus supplementary concentrates. Twenty-six days prior to weaning and housing, 20 singled suckled, pure-bred Simmental male (non-castrated), (n = 10, m) and female (n = 10, f) calves were assigned to one of two treatments (i) concentrate supplement (CS: n = 10 (5 m and 5 f), mean age (s.d.) 201 (12.8) d, mean weight (s.d.) 258 (20.2) kg) or (ii) no concentrate supplement (controls) (NCS: n = 10, (5 m and 5 f), mean age (s.d.) 201 (13.4) d, mean weight (s.d.) 257 (19.6) kg) pre-weaning.</p> <p>Results</p> <p>There was a treatment × sampling time interaction (<it>P </it>< 0.05) for percentage CD4⁺and WC1⁺(γδ T cells) lymphocytes and concentration of plasma globulin. On d 2, percentage CD4⁺lymphocytes decreased (<it>P </it>< 0.001) in both treatments. Subsequently on d 7, percentage of CD4⁺lymphocytes increased (<it>P </it>< 0.01) in CS compared with d 0, whereas percentage of CD4⁺lymphocytes in NCS did not differ (<it>P </it>> 0.05) from d 0. On d 2, WC1⁺lymphocytes decreased (<it>P </it>< 0.05) in both treatments but the decrease was greater (<it>P <</it>0.05) in NCS than CS. Subsequently, percentages did not differ (<it>P </it>> 0.05) from pre-weaning baseline. On d 2, the increase in concentration of globulin was greater (<it>P </it>< 0.05) in CS compared with NCS, and subsequently there was no difference between treatments. Pre-weaning ADG was 1.07 (s.e.m.) (0.26) kg and 0.99 (s.e.m.) (0.26) kg for CS and NCS, respectively. Post-weaning, CS calves spent more time lying compared with NCS calves.</p> <p>Conclusions</p> <p>Calves supplemented with concentrate prior to weaning had a lesser reduction in WC1⁺lymphocytes, increased percentage CD4⁺lymphocytes and concentration of total protein, and spent more time lying post-weaning, compared with non-supplemented calves.</p

Efficient, Responsive, and Robust Hopping on Deformable Terrain

Legged robot locomotion is hindered by a mismatch between applications where legs can outperform wheels or treads, most of which feature deformable substrates, and existing tools for planning and control, most of which assume flat, rigid substrates. In this study we focus on the ramifications of plastic terrain deformation on the hop-to-hop energy dynamics of a spring-legged monopedal hopping robot animated by a switched-compliance energy injection controller. From this deliberately simple robot-terrain model, we derive a hop-to-hop energy return map, and we use physical experiments and simulations to validate the hop-to-hop energy map for a real robot hopping on a real deformable substrate. The dynamical properties (fixed points, eigenvalues, basins of attraction) of this map provide insights into efficient, responsive, and robust locomotion on deformable terrain. Specifically, we identify constant-fixed-point surfaces in a controller parameter space that suggest it is possible to tune control parameters for efficiency or responsiveness while targeting a desired gait energy level. We also identify conditions under which fixed points of the energy map are globally stable, and we further characterize the basins of attraction of fixed points when these conditions are not satisfied. We conclude by discussing the implications of this hop-to-hop energy map for planning, control, and estimation for efficient, agile, and robust legged locomotion on deformable terrain.Comment: 17 pages, 13 figures, submitted to IEEE Transactions on Robotic

Finding the common ground: families, relationships, and child-focused practice in foster care

For children, their parents, and their foster carers, the challenge in maintaining relationships, managing interactions, and varying loyalties can bring a wide range of complex and intense emotions. This often-overlooked emotional complexity within the foster care system lies at the heart of challenges that may arise. This paper explores this complex and uniquely fostering situation of supporting a child in being part of two families. We firstly examine the literature in relation to this issue and then explore the perspectives of the foster carers, multidisciplinary practitioners and the views of parents drawing from recent Irish research. In examining the differing sides of a complex situation for children in foster care, we then explore how we can find some common ground and how to support practices that help children to integrate and make sense of these varying relationships in the interests of their development and wellbeing