358 research outputs found

    Effect of age and nutrient restriction pre partum on beef suckler cow serum immunoglobulin concentrations, colostrum yield, composition and immunoglobulin concentration and immune status of their progeny

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    peer-reviewedThe effect of cow age (multiparous (MP) v. primiparous (PP)) and nutritional restriction pre partum (grass silage ad libitum v. straw only ad libitum for the last 15 (s.d. 3.3) days of gestation) on cow serum immunoglobulin (Ig) concentration, on colostrum yield, composition and Ig concentration and on calf serum Ig concentrations (at ~8 and 48 h post partum) using spring-calving Limousin Holstein-Friesian cows and their progeny was studied over 3 years. The method of colostrum administration (stomach tube vs. assisted suckling within 1 h post partum) on calf immune status was also investigated. When feeding colostrum the target was to give each calf 50 mL per kg birthweight via stomach tube. Colostrum yield and Ig concentration were measured following administration of oxytocin and hand-milking of half (Experiments 1 and 2) or the complete udder (Experiment 3). Following an 8-h period after birth during which suckling was prevented a further colostrum sample was obtained. There was no significant difference in first milking colostrum Ig subclass concentrations between the within-quarter fractions or between the front and rear quarters of the udder in either MP or PP cows. Colostrum Ig subclass concentrations at second milking were 0.46 to 0.65 of that at first milking. Compared to MP cows offered silage, colostrum yield and the mass of colostrum IgG1, IgG2, IgM, IgA and total Ig produced was lower (P < 0.001) for PP cows and the mass of IgG1, IgM and total Ig produced was lower (P < 0.05) for MP cows offered straw. Calves from PP cows and MP cows offered straw had significantly lower serum IgG1 and total Ig concentrations at 48 h post partum than calves from MP cows offered silage but there was no difference (P > 0.05) between colostrum feeding methods. In conclusion, calves from PP cows and MP cows offered straw had a lower humoral immune status than those from MP cows offered grass silage

    Effect of suckler cow genotype on cow serum immunoglobulin (Ig) levels, colostrum yield, composition and Ig concentration and subsequent immune status of their progeny

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    peer-reviewedSurvival of the neonatal calf is largely dependent on humoral immunity. The objective of three experiments reported here was to compare cow serum immunoglobulin (Ig) concentration, colostrum yield, composition and Ig concentration and calf serum Ig concentrations at ~8- and 48-h post partum of spring-calving Charolais (C) and Beef × Holstein-Friesian (BF) cows and their progeny. Cows were individually offered a restricted allowance of grass silage pre partum in Experiments 1 and 2 and silage ad libitum in Experiment 3. In Experiment 1 calves were assisted to suckle after parturition. In Experiments 2 and 3, colostrum yield and Ig concentration were measured following administration of oxytocin and hand milking of half or the complete udder, respectively. It was intended to feed each calf 50 ml (Experiment 2) or 40 ml (Experiment 3) of colostrum per 1 kg birth weight via stomach tube. Following an 8-h period, during which suckling was prevented, a further colostrum sample was obtained. The decrease in cow serum IgG1 concentration pre partum was greater (P < 0.05) in BF cows than C cows. In comparison to BF cows, C cows had a lower colostrum yield (P < 0.001) and the colostrum had lower concentrations of dry matter (P < 0.01), crude protein (P < 0.05), fat (P < 0.05), IgG1 (P = 0.06), IgG2 (P < 0.01), IgM (P < 0.01) and Ig total (P < 0.05). The mass of IgG1, IgG2, IgM, IgA and Ig total in the colostrum produced was significantly lower for C cows than BF cows. Calves from C cows had significantly lower serum Ig subclass concentration at 48-h post partum than calves from BF cows. In conclusion, due to a lower Ig mass produced by their dams, calves from C cows had a lower humoral immune status than those from BF cowsTeagasc Walsh Fellowship Programm

    Functional properties and pharmacology of extrasynaptic GABA-A receptors

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    The “ambient” GABA that is present in the extracellular space surrounding all neurons of the brain is believed to be capable of persistently activating high‐affinity extrasynaptic GABA-A receptors to generate a tonic membrane conductance. This generates a form of shunting inhibition that is capable of influencing cellular and network excitability. Extrasynaptic δ subunit-containing GABA-A receptors are known to generate this form of tonic inhibition in a number of defined brain regions and these are emerging as important clinical drug targets for the treatment of a number of neurological conditions. This thesis examines the functional and pharmacological properties of recombinant and native GABA-A receptors that allow them to function as ambient GABA detectors. Surprisingly, the data presented in this Thesis shows that the behaviour of these extrasynaptic GABA-A receptor populations is dramatically influenced by the steady-state GABA concentration they experience. For example, recombinant α4βδ and α6βδ receptor populations are shown to exhibit profound levels of desensitization in the presence of low ambient GABA levels that will limit their ability to respond to changes in ambient GABA. We also find that the action of certain sedative/hypnotic drugs on extrasynaptic GABA-A receptors expressed in cerebellar granule neurons is critically dependent upon the concentration of ambient GABA. For example, we show that the intravenous anaesthetic propofol will only enhance tonic inhibition when ambient GABA levels are below 100 nM. Similarly, we show that the GABA-A receptor agonist Gaboxadol is not capable of enhancing tonic inhibition when ambient GABA levels are high. In contrast to the behaviour of drugs like propofol and Gaboxadol, we find that neurosteroid enhancement of tonic inhibition will occur regardless of ambient GABA levels. This issue will be important when considering therapeutic strategies to target tonic inhibition in the treatment of neurological disorders. Furthermore, we show for the first time, that copper ions can potently block extrasynaptic GABA-A receptors, suggesting that copper may provide a means to selectively block tonic inhibition in the brain, and may even represent a novel source of extrasynaptic GABA-A receptor modulation in vivo

    The Absence of Malice? In re Christian S., the Second Wind of the Imperfect Self-defense Doctrine

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    This comment will first discuss the background and development of the imperfect self-defense doctrine. The comment will then examine the majority and dissent\u27s analyses in In re Christian S. Finally, the comment will argue that contrary to the majority opinion, imperfect self-defense no longer has a viable foundation, and should no longer be recognized

    XinuPi3: Teaching Multicore Concepts Using Embedded Xinu

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    As computer platforms become more advanced, the need to teach advanced computing concepts grows accordingly. This paper addresses one such need by presenting XinuPi3, a port of the lightweight instructional operating system Embedded Xinu to the Raspberry Pi 3. The Raspberry Pi 3 improves upon previous generations of inexpensive, credit card-sized computers by including a quad-core, ARM-based processor, opening the door for educators to demonstrate essential aspects of modern computing like inter-core communication and genuine concurrency. Embedded Xinu has proven to be an effective teaching tool for demonstrating low-level concepts on single-core platforms, and it is currently used to teach a range of systems courses at multiple universities. As of this writing, no other bare metal educational operating system supports multicore computing. XinuPi3 provides a suitable learning environment for beginners on genuinely concurrent hardware. This paper provides an overview of the key features of the XinuPi3 system, as well as the novel embedded system education experiences it makes possible

    Population Aging: Facts, Challenges, and Responses

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    The world’s population is growing older, leading us into uncharted demographic waters. There will be higher absolute numbers of elderly people, a larger share of elderly, longer healthy life expectancies, and relatively fewer numbers of working-age people. There are alarmist views – both popular and serious – in circulation regarding what these changes might mean for business and economic performance. But the effects of population aging are not straightforward to predict. Population aging does raise some formidable and fundamentally new challenges, but they are not insurmountable. These changes also bring some new opportunities, because people have longer, healthier lives, resulting in extended working years, and different capacities and needs. The key is adaptation on all levels: individual, organizational, and societal. This article explores some potentially useful responses from government and business to the challenges posed by aging.population, aging, longevity, fertility

    Production and carcass traits of high dairy genetic merit Holstein, standard dairy genetic merit Friesian and Charolais × Holstein-Friesian male cattle

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    peer-reviewedThe increased proportion of Holstein genetic material in the dairy herd has consequences for beef production in Ireland. A total of 72 spring-born male calves (24 Holsteins (HO), 24 Friesian (FR) and 24 Charolais × Holstein-Friesians (CH)) were reared from calfhood to slaughter. Calves were artificially reared indoors and spent their first summer at pasture following which they were assigned, on a breed basis, to a factorial combination of two production systems (intensive 19-month bull beef and extensive 25-month steer beef) and two slaughter weights (560 and 650 kg). After slaughter the pistola hind quarter was separated into fat, bone and muscle. Live-weight gain, carcass gain, kill-out proportion, carcass conformation and carcass fat scores were 830, 811 and 859 (s.e. 14.9) g/day, 540, 533, 585 (s.e. 7.7) g/day, 526, 538 and 561 (s.e. 3.0) g/kg, 1.51, 2.18 and 2.96 (s.e. 0.085), and 3.40, 4.25 and 4.06 (s.e. 0.104) for HO, FR and CH, respectively. Corresponding values for pistola weight as a proportion of carcass weight, pistola muscle proportion and pistola fat proportion were 458, 459 and 461 (s.e. 2.6) g/kg, 657, 645 and 667 (s.e. 3.7) g/kg, and 132, 161 and 145 (s.e. 4.1) g/kg. Compared with the intensive system, animals on the extensive system had a lower (P < 0.001) daily live-weight gain, kill-out proportion and a lower muscle proportion in the pistola. Increasing slaughter weight increased (P < 0.001) carcass weight and carcass fat score and reduced the proportion of muscle in the pistola. Allometric regression coefficients for pistola weight on side weight, and total bone, muscle and fat weights on pistola weight were 0.898, 0.755, 0.900 and 1.910 respectively. It is concluded that HO grew at least as fast as FR but had a lower killout proportion. Carcass conformation and fat scores were greater for FR than for HO and muscle proportion in the pistola was lower and total fat proportion was higher. Compared with FR, CH had heavier carcasses, a higher kill-out proportion and less fat and more muscle in the pistola

    Body and carcass measurements, carcass conformation and tissue distribution of high dairy genetic merit Holstein, standard dairy genetic merit Friesian and Charolais x Holstein-Friesian male cattle

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    peer-reviewedThe increased proportion of Holstein genes in the dairy herd may have undesirable consequences for beef production in Ireland. A total of 72 spring-born calves, (24 Holstein (HO), 24 Friesian (FR) and 24 Charolais X Holstein-Friesian (CH)) were reared from calfhood to slaughter. Calves were artificially reared indoors and spent their first summer at pasture following which they were assigned to a 3 breeds (HO, FR and CH) 2 production systems (intensive 19-month bull beef and extensive 25-month steer beef) 2 slaughter weights (560 and 650 kg) factorial experiment. Body measurements of all animals were recorded at the same time before the earliest slaughter date. After slaughter, carcasses were graded and measured and the pistola hind-quarter was separated into fat, bone and muscle. HO had significantly higher values for withers height, pelvic height and chest depth than FR, which in turn had higher values than CH. HO had a longer back and a narrower chest than either FR or CH, which were not significantly different. Carcass length and depth, pistola length, and leg length were 139.2, 134.4 and 132.0 (s.e. 0.81), 52.1, 51.3 and 47.7 (s.e. 0.38), 114.4, 109.0 and 107.0 (s.e. 0.65) and 76.7, 71.9 and 71.4 (s.e. 0.44) cm for HO, FR and CH, respectively. Breed differences in pistola tissue distribution between the joints were small and confined to the distal pelvic limb and ribs. There were relatively small breed differences in the distribution of pistola muscle weight between individual muscles. Body measurements were significantly greater for animals on the intensive system (bulls) than the extensive system (steers) in absolute terms, but the opposite was so when they were expressed relative to live weight. The only significant difference in relative carcass measurements between the production systems was for carcass depth, which was lower for the intensive compared with the extensive system. Increasing slaughter weight significantly increased all carcass measurements in absolute terms but reduced them relative to weight. It is concluded that there were large differences between the breed types in body and carcass measurements, and hence in carcass shape and compactness but differences in tissue distribution were small
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