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Aims Our main aim was to describe the trend in the comorbidities of patients undergoing elective total hip arthroplasties (THAs) and knee arthroplasties (KAs) between 1 January 2005 and 31 December 2018 in England. Methods We combined data from the National Joint Registry (NJR) on primary elective hip and knee arthroplasties performed between 2005 and 2018 with pre-existing conditions recorded at the time of their primary operation from Hospital Episodes Statistics. We described the temporal trend in the number of comorbidities identified using the Charlson Comorbidity Index, and how this varied by age, sex, American Society of Anesthesiologists (ASA) grade, index of multiple deprivation, and type of KA. Results We included 696,504 and 833,745 elective primary THAs and KAs respectively, performed for any indication. Between 2005 and 2018, the proportion of elective THA and KA patients with one or more comorbidity at the time of their operation increased substantially (THA: 20% to 38%, KA: 22% to 41%). This was driven by increases in four conditions: chronic obstructive pulmonary disease (COPD) (2018: ~17%), diabetes without complications (2018: THA 10%, KA 14%), myocardial infarction (2018: 4%), and renal disease (2018: ~8%). Notably, renal disease prevalence increased from < 1% in 2005 to ~8% in 2018. Conclusion Between 2005 and 2018 there were significant changes in the number of comorbidities recorded in patients having elective primary THAs and KAs. Renal disease is now one of the most prevalent comorbidities in this patient population. Future research should explore whether this comorbidity trend has increased the burden on other medical specialities to optimize these patients before surgery and to provide additional postoperative care. Cite this article: Bone Joint J 2022;104-B(9):1052–1059.

Molecular magnets are one of the key research themes of µSR, but locating the muon stopping site in these compounds using density functional theory is often very challenging as their unit cells tend to contain a very large number of atoms. Nevertheless, many molecular magnets contain the [PF6]− and [BF4]− molecular ions, which, due to their fluorine nuclei, produce a distinctive µSR spectrum, which can give information about the muon stopping site. This paper details the calculation of the muon sites in the much simpler materials KPF6 and KBF4, providing insights which can be applied to situations where these molecular ions are found in complicated molecular magnets.

Animals form an integral part of our planetary ecosystem but balance is critical to effective ecosystem functioning as demand for livestock products has increased, greater numbers of domesticated livestock have created an imbalance and hence had a negative impact on a number of ecosystem services which means that life as we know it will become unsustainable. Policies and technology advances have helped to manage the impact but more needs to be done. The aim of this paper is to highlight ways in which better knowledge of animal science, and other disciplines, can both harness technology and inform policy to work towards a sustainable balance between livestock and the environment. Effective policies require simple, quantifiable indicators against which to set targets and monitor progress. Indicators are clear for water pollution, but more complex for biodiversity. Hence, more progress has been made with the former. It is not yet possible to measure the impacts of changes in livestock management on greenhouse gas emissions per se at a farm level and progress has been slower, although new technologies are emerging. With respect to land use, the simple indicator of area has been used, but total area is oversimplistic. Our analysis of land suitability and use highlights a relatively overlooked role of livestock in acting as a ‘buffer’ to use by-products and grains which do not meet the standards for processing by industry during years of inclement weather, which in the past has provided an ‘insurance policy’ for farmers. Since extreme weather events are increasing in frequency with climate change, this role for livestock may be more important in future. The conclusions of the review with respect to strengthening the links between research and policy are i) to encourage animal scientists to identify the relevant environmental indicators, work with the cutting edge experts developing technologies to measure these cost-effectively and across a range of relevant livestock systems and ii) to work with the feed industry to optimize diets not just in terms of least cost financially but also least ‘cost’ in terms of global carbon flux and engage in dialogue with the food industry and policy makers on regulations for grain quality.

The drive to increase the output of animal product in some sectors of ruminant livestock production has led to greater use of feeds such as cereal grains and soyabean meal that are potentially human-edible. This trend has caused concern since, by so doing, ruminants compete not only with monogastric livestock but also with the human population for a limited global area of cultivatable land on which to produce grain crops. Reasons for using potentially human-edible feeds in ruminant diets include increased total daily energy intake, greater supply of essential amino acids and improved ruminal balance between fermentable energy and degradable protein. Soyabean meal, produced on land that has been in arable cultivation for many years can fulfil a useful role as a supplier of undegraded dietary protein in diets for high-yielding dairy cows. However, in the context of sustaining the production of high-quality foods from livestock to meet the demands of a growing human population, the use of potentially human-edible feed resources by livestock should be restricted to livestock with the highest daily nutrient requirements; that is, potentially human-edible feed inputs should be constrained to meeting requirements for energy and protein and to rectifying imbalances in nutrient supply from pastures and forage crops such as high concentrations of nitrogen (N). There is therefore a role for human-edible feeds in milk production because forage-only systems are associated with relatively low output per head and also low N use efficiency compared with systems with greater reliance on human-edible feeds. Profitability on farm is driven by control of input costs as well as product value and examples are given of low-cost bovine milk and meat production with little or no reliance on potentially human-edible feeds. In beef production, the forage-only systems currently under detailed real-time life-cycle analysis at the North Wyke Farm Platform, can sustain high levels of animal growth at low feed cost. The potential of all-forage diets should be demonstrated for a wide range of ruminant milk and meat production systems. The challenge for the future development of ruminant systems is to ensure that potentially human-edible feeds, or preferably human-inedible by-products if available locally, are used to complement pastures and forage crops strategically rather than replace them.

Highlights of progress in the production of silage over the past 50 years include the introduction of improved hybrids of maize (Zea mays L.), the forage harvester, the big baler, polyethylene covering for horizontal silos, stretch-wrap film for bales and novel additives designed to improve the fermentation and aerobic stability of silage. The key biochemical pathways in the silage fermentation have been described together with the effects of microbial and chemical additives on fermentation and aerobic stability during the feed-out phase. The significance of oxygen and water in silage fermentation has been quantified and efficacy of covering silos has been established, with recent progress in the development of oxygen barrier film. Future perspectives include improving food safety and animal health by increasing the hygienic quality of silage, reducing the environmental impact of silage by decreasing loss of nitrogen to soil and atmosphere, reducing methanogenesis in the rumen and increasing methane yield from silage as biofuel, and the use of silages as feedstocks for multiple end uses in biorefineries.

The unitary evolution of a quantum system preserves its coherence, but interactions between the system and its environment result in decoherence, a process in which the quantum information stored in the system becomes degraded. A spin-polarized positively-charged muon implanted in a fluoride crystal realises such a coherent quantum system, and the entanglement of muon and nearest-neighbour fluorine nuclear spins gives rise to an oscillatory time-dependence of the muon polarization which can be detected and measured. Here we show that the decohering effect of more distant nuclear spins can be precisely modelled, allowing a very detailed description of the decoherence processes coupling the muon-fluorine 'system' with its 'environment', and allowing us to track the system entropy as the quantum information degrades. These results show how to precisely quantify the spin relaxation of muons implanted into quantum entangled states in fluoride crystals, a feature that has hitherto only been described phenomenologically., Comment: 14 pages, 3 figures

Losses of dry matter and metabolisable energy (ME) occur in silage making due to delayed harvest and also between field and feed trough due to fermentation and aerobic spoilage. Farmers should aim to exert greater control of silage making operations to improve timeliness of harvest and to minimise losses of nutrients. Concentrate input per unit of milk production is often higher than optimal which is more often a reflection of low silage quality than of wasteful overfeeding. A week's delayed harvest of grass is estimated to incur a net cost of 13 pence per cow per day of winter feeding. Mowing a dry crop and spreading it out to maximise rate of water loss during the wilting period can reduce losses in the field. Consolidation of crop in the silo to achieve a minimum fresh weight density of 700 kg/m3 and dry matter (DM) density of 210 kg/m3 will help to minimise losses during the storage period, paying particular attention to the outermost layer which should be covered with an oxygen barrier film. A feed-out progression rate of at least 1 metre per week in winter and 1.5 to 2 metres per week in summer, coupled with harvesting a clean crop with low yeast and mould counts will help to reduce losses during feed-out. Many bunker silos are too old, too small, have no safety rail and are over-filled. Safety issues should be considered at all stages of silage making. Appropriate steps should be taken wherever possible to minimise risk of injury.

Silage may contain several agents that are potentially hazardous to animal health, the safety of milk or other animal food products, or both. This paper reviews published literature about microbial hazards, plant toxins, and chemical hazards. Microbial hazards include Clostridium botulinum, Bacillus cereus, Listeria monocytogenes, Shiga toxin-producing Escherichia coli, Mycobacterium bovis, and various mold species. High concentrations of C. botulinum in silage have been associated with cattle botulism. A high initial concentration of C. botulinum spores in forage in combination with poor silage fermentation conditions can promote the growth of C. botulinum in silage. The elevated pH level that is generally associated with aerobic deterioration of silage is a major factor influencing concentrations of L. monocytogenes, Shiga toxin-producing E. coli, and molds in silage and may also encourage survival and growth of M. bovis, the bacterium that causes bovine tuberculosis. Soil is a major source of B. cereus spores in silage; growth of this bacterium in silage appears to be limited. Hazards from plant toxins include pyrrolizidine, tropane and tropolone alkaloids, phytoestrogens, prussic acid, and mimosine, compounds that exist naturally in certain plant species that may contaminate forages at harvesting. Another group of toxins belonging to this category are ergot alkaloids, which are produced by endophytic fungal species in forages such as tall fescue grass, sorghum, and ryegrass. Varying effects of ensiling on the degradation of these plant toxins have been reported. Chemical hazards include nitrate, nitrite, and toxic oxide gases of nitrogen produced from nitrate and high levels of butyric acid, biogenic amines, and ammonia. Chemical and microbiological hazards are associated with poorly fermented silages, which can be avoided by using proper silage-making practices and creating conditions that promote a rapid and sufficient reduction of the silage pH and prevent aerobic deterioration.

To investigate whether elective joint arthroplasty performed at the weekend is associated with a different 30-day mortalityWe examined the 30-day cumulative mortality rate (Kaplan-Meier) for all elective hip and knee arthroplasties performed in England and Wales between 1st April 2003 and 31st December 2014, comprising 118 096 episodes undertaken at the weekend and 1 233 882 episodes performed on a weekday. We used Cox proportional-hazards regression models to assess for time-dependent variation and adjusted for identified risk factors for mortality.The cumulative 30-day mortality for hip arthroplasty was 0.15% (95% confidence interval (CI) 0.12 to 0.19) for patients operated on at the weekend versus 0.20% (95% CI 0.19 to 0.21) for patients undergoing surgery during the normal working week. For knee arthroplasty, the cumulative 30-day mortality was 0.14% (95% CI 0.11 to 0.17) for weekend-operated patients versus 0.18% (95% CI 0.17 to 0.19) for weekday-operated patients. These differences were independent of any differences in patient age, gender, American Society of Anaesthesiologists grade, surgeon seniority, surgical and anaesthetic practices, and thromboprophylaxis choice in weekendThe 30-day mortality rate after elective joint arthroplasty is low. Surgery performed at the weekend is associated with lower post-operative mortality

A meta-analysis was undertaken of 51 comparisons of standard polyethylene film with oxygen barrier (OB) film in covering systems for bunker silos, unwalled clamp silos and bales. Mean losses of DM or OM during storage from the top 10 to 60 cm of bunker and clamp silos were 195 g kg−1 for standard film and 114 g kg−1 for OB film systems (41 sets of data, P

SummaryThe concentration of crude protein in grazed New Zealand pasture is typically in excess of 200 g/kg DM, which exceeds the requirement of the dairy cow and is reflected in elevated levels of daily urinary nitrogen (N) excretion, estimated to average 262 g N/head or 751 kg N/ha. This has adverse environmental consequences, including leaching of nitrate from soil into water courses and atmospheric emissions of nitrous oxide. Problems associated with pasture as the sole feed for dairy cows include weight loss in early lactation, poor fertility and reduced lactation length. Low-protein supplements can reduce N excretion rates and increase N use efficiency. A simple feeding strategy is proposed in which pasture is supplemented with maize or whole-crop wheat silage at 5 kg DM/cow per day from the start of the pre-calving dry period on winter run-off pasture to 100 days post-calving, and from 250 days post-calving to the end of lactation. The expected response, at an assumed substitution rate of 0.7 kg decrease in pasture intake per kg silage DM, is an increase in metabolisable energy of 10 to 15 MJ/cow/day, equivalent to 33 to 48 g milk solids (MS)/kg DM of supplement. This strategy is expected to result in significantly lower urinary N excretion by the cow. Actual responses in daily milk output, from published experiments where grazing stocking rates were increased to take account of reduced herbage intake, ranged from 50 to 100 g MS/kg DM of supplement. Other benefits include early lactation bodyweight maintenance, higher percentage of cows calved which are pregnant at 150 days in milk and increased lactation period. Constraints for farmers to implement such changes include cost of silage, value of milk sold, failure to integrate forage maize or wheat in rotational cropping with pasture, and the relatively poor aerobic stability of maize and whole-crop wheat silages.

When silage is exposed to air on opening the silo, or after its removal from the silo, fermentation acids and other substrates are oxidized by aerobic bacteria, yeasts and moulds. The aerobic stability of silage is a key factor in ensuring that silage provides well-preserved nutrients to the animal with minimal amounts of mould spores and toxins. In this paper, key findings and recent developments are reviewed, and findings of recent research are integrated in terms of four themes: (i) the most significant biochemical and microbiological factors, (ii) physical and management factors, (iii) type of additive and (iv) silo sealing. The development of yeasts and moulds during plant growth, and during field wilting or storage, and the concentration of undissociated acetic acid in silage are important microbiological and biochemical factors affecting aerobic stability. Silage density and porosity are key physical factors that affect the rate of ingress of oxygen into the silage mass during the feed-out period. A target for potential silage aerobic stability is 7 d including time in the feed trough. To achieve this target, speed of harvest should be coordinated with packing tractor weight to achieve a minimum silage density by the time of feed-out of 210 kg DM m−3, maximum proportional porosity of 0·4 and a rate of silage removal, which matches or exceeds the depth of air penetration into the silo. The use of additives to increase aerobic stability is advisable when there is the risk of these objectives not being met. Novel microbial approaches to solving the problem of silage aerobic deterioration are needed.

Livestock contribute directly (i.e. as methane and nitrous oxide (N2O)) to about 9% of global anthropogenic greenhouse gas (GHG) emissions and around 3% of UK emissions. If all parts of the livestock production lifecycle are included (fossil fuels used to produce mineral fertilizers used in feed production and N2O emissions from fertilizer use; methane release from the breakdown of fertilizers and from animal manure; land-use changes for feed production and for grazing; land degradation; fossil fuel use during feed and animal production; fossil fuel use in production and transport of processed and refrigerated animal products), livestock are estimated to account for 18% of global anthropogenic emissions, but less than 8% in the UK. In terms of GHG emissions per unit of livestock product, monogastric livestock are more efficient than ruminants; thus in the UK, while sheep and cattle accounted for 32% of meat production in 2006, they accounted for ∼48% of GHG emissions associated with meat production. More efficient management of grazing lands and of manure can have a direct impact in decreasing emissions. Improving efficiency of livestock production through better breeding, health interventions or improving fertility can also decrease GHG emissions through decreasing the number of livestock required per unit product. Increasing the energy density of the diet has a dual effect, decreasing both direct emissions and the numbers of livestock per unit product, but, as the demands for food increase in response to increasing human population and a better diet in some developing countries, there is increasing competition for land for food v. energy-dense feed crops. Recalculating efficiencies of energy and protein production on the basis of human-edible food produced per unit of human-edible feed consumed gave higher efficiencies for ruminants than for monogastric animals. The policy community thus have difficult decisions to make in balancing the negative contribution of livestock to the environment against the positive benefit in terms of food security. The animal science community have a responsibility to provide an evidence base which is objective and holistic with respect to these two competing challenges.

To test whether or not the ‘stay-green’ (SG) characteristic confers benefits in terms of crop yield or distribution of dry matter (DM) in selected forage maize cultivars, an experiment was conducted in 1998 and 1999 at two sites in England: Writtle College, Essex and the University of Leeds, West Yorkshire. Five SG and five conventional (C) cultivars of forage maize were grown in replicated field-scale plots at each site in both years. One-metre lengths of single rows in each plot were harvested by hand, leaving a 20-cm stubble, on four occasions each year over 3-week periods (harvest 1 to harvest 4), prior to the harvest of the remainder of the fields. Plants were chopped, mixed and a subsample taken for determination of DM content by oven-drying. Mean yields of whole plant DM were similar between SG and C cultivars. Both yield of DM and proportion of ear in the total plant DM increased from harvest 1 to harvest 4 (P

The recycling of sewage sludge or biosolids to grassland is strategically important in the European Union (EU) and its use is tightly regulated to control the risk of pathogen transfer to animals and the food chain. Sewage sludges not only contain valuable concentrations of beneficial nutrients, but also elevated concentrations of potentially toxic metals (PTM) compared with average background concentrations in the soil. The EC and UK regulations refer to six PTM, Cd, Pb, Cu, Zn, Ni and Hg, with provisional regulations for Cr, that have to be controlled to prevent detrimental effects on soil and animal health. Despite these regulations, there is still a danger that grazing animals may ingest elevated concentrations of PTM. Biosolids may adhere to herbage after the surface application of sewage sludge to grassland. The repeated surface application of sewage sludge to grassland can lead to elevated concentrations of PTM at the soil surface that may be ingested, together with soil and herbage, by grazing ruminants. This may lead to accumulation of Cd or Pb in liver or kidney. The risk to the human food chain is considered to be low, but the impact on the environment is still unknown. There is little information, for example, on the amount of soil and PTMs that may become incorporated into conserved grass. At present EU and UK legislation and voluntary codes of practice have been developed to protect animal from pathogens in sewage sludge and to minimize any potential risks from accumulation of PTM. The background and implementation of the legislation are examined in this review, and the source and mechanisms of accumulation of PTM by the grazing animal are evaluated.

The main factors affecting the accumulation of potentially-toxic metals (PTM) by grazing animals are the presence of the metal, its concentration in herbage and at the soil surface, and the duration of exposure to the contaminated pasture and soil. In addition, the elapsed time between the contamination of the pasture and grazing, the quantity of soil ingested together with herbage, the mechanism of absorption of the metal into blood and the presence or absence of antagonistic metals can interact to influence the rate and extent of accumulation of heavy metals in edible body tissues. Models of the accumulation of metals by grazing animals may be used to determine the statutory limits of radionuclides and PTM in soils under grazed pastures. Meta-analysis of existing data, using a random-effects model, is a useful approach to understanding the factors affecting the accumulation of some metals, e.g. Cd. The target edible body tissues for the accumulation of most PTM are the liver and kidneys, with the exception of radiocaesium, which accumulates in muscle to a greater extent than in other tissues. The livers and kidneys of mature livestock that have been grazed on areas of pasture at the legal limit of contamination by Cd for more than one grazing season should be removed from the human food chain in order to reduce the risk of intake of Cd by the human population.

Life-cycle analysis showed that the lowest emissions of greenhouse gases (GHG) were from poultry meat and the highest from suckler beef production. Differences between systems in GHG per unit of edible energy were less than per kg product. Suckler beef and sheep had higher emissions than other livestock systems, reflecting the overhead cost of the breeding female. There is a huge range in emissions between farms but no major differences between upland and lowland enterprises. The most profitable units are also the greenest. Improvements in animal health status also reduce GHG/kg product by increasing survival rates and the productive life of breeding females.

Methane production is lower from ruminants given diets which produce less acetate and more propionate. This means using diets higher in starch and lower in fibre. There are implications of this feeding strategy for animal health. Reducing the concentration of N in the animal’s diet is likely to lead to a reduction in nitrous oxide emissions. Both methane per kg product and the percentage of dietary N which is converted into N in animal products are influenced strongly by the level of animal output. Improving feed conversion ratio and nitrogen use efficiency should result in reduced greenhouse gas emissions from livestock.

Methane is produced from carbon dioxide and hydrogen as a by-product of rumen fermentation. Excess hydrogen is produced together with the production of acetate and butyrate but not with the production of propionate and valerate. Diets lower in fibre and higher in starch result in higher proportions of propionate in the rumen volatile fatty acids and less methane per mole of substrate fermented. There is significant variation between animals in methane production. Research is underway to refine methane emissions factors for different classes of livestock. Smaller amounts of methane are also produced in the hind gut and from manure.

We aimed to evaluate the precision and longitudinal sensitivity of measurement of bone mineral density (BMD) in the pelvis and to determine the effect of bone cement on the measurement of BMD in femoral regions of interest (ROI) after total hip arthroplasty (THA). A series of 29 patients had duplicate dual-energy x-ray absorptiometry (DXA) scans of the hip within 13 months of THA. Pelvic analyses using 3- and 4-ROI models gave a coefficient of variation (CV) of 2.5% to 3.6% and of 2.5% to 4.8%, respectively. Repeat scans in 17 subjects one year later showed a significant change in BMD in three regions using the 4-ROI model, compared with change in only one region with the 3-ROI model (p < 0.05). Manual exclusion of cement from femoral ROIs increased the net CV from 1.6% to 3.6% (p = 0.001), and decreased the measured BMD by 20% (t = 12.1, p < 0.001). Studies of two cement phantoms in vitro showed a small downward drift in bone cement BMD giving a measurement error of less than 0.03 g/cm2/year associated with inclusion of cement in femoral ROIs. Changes in pelvic periprosthetic BMD are best detected using a 4-ROI model. Analysis of femoral ROI is more precise without exclusion of cement although an awareness of its effect on the measurement of the BMD is needed.

Ingestion of sewage sludge with soil, together with herbage containing elevated concentrations of potentially toxic elements (PTEs) might pose a risk to the human food chain through the accumulation of PTEs in edible tissues of livestock grazed on pastures which have received repeated doses of sludge. The accumulation of PTEs in tissues of animals grazed on a permanent pasture which had received repeated applications of sewage sludge between 1981 and 1994 was studied over two consecutive grazing seasons by monthly serial slaughter. Blocks of six weaned lambs were allocated at random at the start of the grazing seasons to slaughter date. Blocks of lambs were also allocated at random to an adjacent untreated pasture and to initial slaughter groups. Animals grazed continuously for two periods of 181 days and 152 days in 1994 (experiment 1) and 1995 (experiment 2), respectively. An application of sewage sludge was made to the treated site between the two experiments. The concentration of cadmium (Cd) in soil samples taken to 25 cm depth from the treated site was close to the United Kingdom statutory limit of 3 mg Cd per kg dry matter (DM) and 1·67 times the limit at the soil surface. Concentrations of other PTEs in soil were below statutory limis. The concentrations of PTEs in herbage at the treated site increased as each grazing period advanced (P < 0·05). Mean concentrations of Cd, lead (Pb), copper (Cu) and zinc (Zn) were higher (P < 0·05) in both experiments for herbage at the treated site than at the untreated site. No differences were observed in the concentrations of PTEs in muscle tissue between lambs grazed on treated or untreated pastures. The concentration of Cd in kidneys of lambs grazed on the treated pasture increased as the grazing seasons progressed from 0·19 to 0·36 mg/kg DM (P < 0·01) in experiment 1 and from 0·03 to 2·57 mg/kg DM in experiment 2 (P < 0·001). There was no measurable accumulation of Pb into kidney in either experiment. Concentrations of Cu in kidney remained similar during experiment 1 but increased during experiment 2 in lambs grazed on the treated pasture only (P < 0·05). Similar trends to those for kidney were observed for Cd in liver in both experiments. The concentrations of Pb increased in liver for lambs grazed on the treated site in experiment 1 (P < 0·01) but not in experiment 2. The concentrations of Cu in lambs grazed on the treated pasture in liver decreased (P < 0·01) in experiment 1 from 139 to 28 mg Cu per kg DM. Liver concentrations of Cu in experiment 2 increased (P < 0·01) from 63·5 to 197 mg Cu per kg DM, possibly reflecting the application of sludge to the experimental site between the two experiments. The results indicated that soil and herbage concentrations of PTEs were elevated following repeated applications of sewage sludge to grassland. The accumulation of PTEs in edible body tissues was generally low, with the greatest being of Cd and Cu in the second experiment, possibly reflecting recent application of sludge.

The health and welfare of dairy cows are dependent upon the stockpersons who handle, observe and monitor them. The attitudes and behaviour of these people have been little studied, although they are fundamental for the animals' well-being and performance. The results of a series of standardised interviews with 238 dairy stockpersons are discussed. Milking was considered both the most important and the most enjoyed task, and the most disliked task was cleaning the parlour and yards. These attitudes can affect the health of the herd. The stockpersons valued their interaction with animals; 'a special event involving the cows' was frequently mentioned as the component of a 'good' day, and a 'bad event involving the cows' was almost unanimously the factor associated with a 'bad' day.

The process of preserving crops by fermentation in silos is under the control of the farmer to a much lesser degree compared to the level of control by the manufacturer over the production of other fermented foods, such as cheese and yoghurt. Additives designed to direct the extent and pattern of the fermentation are relatively unpopular in most countries, and their use is not guaranteed to remove the risk of undesirable components in silage. Hazards to animal health associated with silage fall into three categories: (1) undesirable micro-organisms e.g. Listeria, enterobacteria, clostridia and moulds; (2) undesirable chemicals, e.g. mycotoxins, and (3) excess acidity and other metabolic disorders. In some regions of Europe, the production of silage is discouraged or prohibited because of the risk of undesirable microbes. The principal risk in these areas is that of the secondary fermentation of cheese made from milk contaminated by bacterial spores, rather than a direct hazard of contaminated silage to animal health. With the possible exception of high dry matter silage conserved in large bales, respiratory hazards to animals from moulds and their spores generally are less from silage than hay. Mycotoxins and phytoestrogens may survive the ensiling period and constitute risks to animal health. Relatively little is known about the epidemiology of diseases that may be linked to undesirable chemicals and excess acidity in silage. Therefore, research is needed to define epidemiologically and mechanistically the risks to animal health and to the human food chain from silages contaminated with pathogenic bacteria and mycotoxins, and to understand more completely the relationships between the physical and chemical compositions of silage and metabolic disorders in animals. Copyright © 1999 John Wiley & Sons, Ltd.

Current European Union legislation will increase the level of disposal of sewage sludge to agricultural land in the next 10 years. This increase may lead to an increase in ingestion, by grazing animals, of herbage with elevated levels of potentially toxic elements (PTEs) derived from sludge adhered to the herbage or sewage sludge-amended soil resulting in the accumulation of PTEs in body tissues, especially the liver and kidney. To assess the possible accumulation of PTEs from soils treated historically with sewage sludge, eight groups of housed weaned lambs were given either dried grass as a sole food (grass control), or diets comprising dried grass (0·9 of total diet dry matter (DM)) and soil (0·1 of total diet DM) from two experimental sites, plots within which had been treated 14 years previously with different quantities of sewage sludge. Soils from the two sites (Cassington and Royston) had contrasting physical characteristics, pH and contents of calcium. The soil from the site at Cassington was slightly acidic (pH 6·0) and had a concentration of calcium of 7·92 g/kg DM whereas the soil from the site at Royston was alkaline (pH 8·0) and had a high concentration of calcium (23·5 g/kg DM). Plots at each site had a range of concentrations of cadmium (Cd) in the soil up to three times the United Kingdom (UK) statutory limit of 3 mg Cd per kg DM. The soils from these two sites were designated control — no amendment with sewage sludge (0·69 mg Cd per kg DM), low (3·55 mg Cd per kg DM), medium (6·63 mg Cd per kg DM) and high (8·82 mg Cd per kg DM; Cassington soil only). Voluntary DM intake of diets by weaned lambs (mean 1436 glday) was not affected significantly by any dietary treatment. The concentrations of Cd in liver increased (P < 0·001) from 0·061 and 0·072 mg/kg DM (Royston and Cassington control, respectively) to 0·218 and 0·403 mg/kg DM (Royston and Cassington medium, respectively) and 0·500 mg/kg DM (Cassington high). The concentrations of Pb in liver increased (P < 0·001) from 0·733 and 0·627 mg/kg DM (Royston and Cassington control, respectively) to 118 and 1·25 mg/kg DM (Royston and Cassington medium, respectively) and 1·18 mg/kg DM (Cassington high). Similar changes were observed for concentrations of Cd and Pb in kidney. A depletion of the concentration of Cu in the liver was observed in all treatments containing soil in the diet. The rate of accumulation of Cd in the liver ranged from 0 to 0·35 μg/g daily tissue DM growth and in the kidney ranged from 0 to 0·44 μg/g daily tissue DM growth. The rate of accumulation of Pb in the liver ranged from 0 to 6·01 μg/g daily tissue DM growth and in the kidney ranged from 0 to 0·63 μg/g daily tissue DM growth. No significant accumulation of PTEs was observed in muscle tissue. It is concluded that the current UK statutory limits for the concentrations ofCd and Pb in soils treated with sewage sludge should be reviewed in the light of these results, though they require confirmation in the grazing situation.

Increasing amounts of sewage sludge will be applied to agricultural land over the next 10 years as a result of the prohibition of its disposal to the sea. The addition of potentially toxic elements (PTEs) to the soil via sewage sludge is controlled by European legislation designed to limit the accumulation of PTEs in soil which could give rise to toxicity to plants or livestock. However the possibility exists that direct ingestion of sewage sludge and soil together with grazed herbage may result in accumulation of PTEs in body tissues. To assess the extent of accumulation of PTEs by direct ingestion of soil and sewage sludge 12 groups of housed weaned lambs were given diets ad libitum comprising dried grass (900 g/kg total diet dry matter (DM)) and three different soils (100 glkg total diet DM). Soil was replaced by dried digested sewage sludge at levels ofO (level 0), 75 (level 1), 150 (level 2) and 300 g/kg soil DM (level 3). Voluntary intake of DM was markedly depressed by the inclusion of sewage sludge in the diet (on average by 24 g DM per g sewage sludge DM addition). There was no effect of sewage sludge on diet apparent digestibility. Live-weight gain was depressed (P < 0·001) by the addition of sewage sludge to the diet from 236 glday (level 0) to 141 glday (level 3). Liver and kidney weights were also reduced (P < 0·01). The apparent availability coefficients for Cd, Pb and Cu increased with increasing level of sewage sludge in the diet fP < 0·05), as did their concentrations in the liver and kidney (P < 0·01). Concentrations of Cd and Pb in liver increased from

To initiate studies on the regulation of tu- bulin expression and microtubule organization in the phytopathogenic Oomycete, Phytophthora cinna- momi, a gene encoding 3-tubulin was cloned and se- quenced. The gene has no introns and encodes a protein of 445 amino acids. Genomic Southern blots indicate a single copy of the 3-tubulin gene in the P cinnamomi genome. Comparison of the P cinnamomi B3-tubulin gene sequence with B3-tubulin genes from a range of fungi, algae and protists supports the hy- pothesis that the Oomycetes are more closely related to the algae and protists than they are to the higher fungi.

SummaryWe report the characterization of a monoclonal antibody (MAb) PM6/13 which recognises glycoprotein IIIa (GPIIIa) on platelet membranes and in functional studies inhibits platelet aggregation induced by all agonists examined. In platelet-rich plasma, inhibition of aggregation induced by ADP or low concentrations of collagen was accompanied by inhibition of 5-hydroxytryptamine secretion. EC50 values were 10 and 9 [H9262]g/ml antibody against ADP and collagen induced responses respectively. In washed platelets treated with the cyclooxygenase inhibitor, indomethacin, PM6/13 inhibited platelet aggregation induced by thrombin (0.2 U/ml), collagen (10 [H9262]g/ml) and U46619 (3 [H9262]M) with EC50 = 4, 8 and 4 [H9262]g/ml respectively, without affecting [14C]5-hydroxytryptamine secretion or [3H]arachidonate release in appropriately labelled cells. Studies in Fura 2-labelled platelets revealed that elevation of intracellular calcium by ADP, thrombin or U46619 was unaffected by PM6/13 suggesting that the epitope recognised by the antibody did not influence Ca2+ regulation. In agreement with the results from the platelet aggregation studies, PM6/13 was found to potently inhibit binding of 125I-fibrinogen to ADP activated platelets. Binding of this ligand was also inhibited by two other MAbs tested, namely SZ-21 (also to GPIIIa) and PM6/248 (to the GPIIb-IIIa complex). However when tested against binding of 125I-fibronectin to thrombin stimulated platelets, PM6/13 was ineffective in contrast with SZ-21 and PM6/248, that were both potent inhibitors. This suggested that the epitopes recognised by PM6/13 and SZ-21 on GPIIIa were distinct. Studies employing proteolytic dissection of 125I-labelled GPIIIa by trypsin followed by immunoprecipitation with PM6/13 and analysis by SDS-PAGE, revealed the presence of four fragments at 70, 55, 30 and 28 kDa. PM6/13 did not recognize any protein bands on Western blots performed under reducing conditions. However Western blotting analysis with PM6/13 under non-reducing conditions revealed strong detection of the parent GP IIIa molecule, of trypsin treated samples revealed recognition of an 80 kDa fragment at 1 min, faint recognition of a 60 kDa fragment at 60 min and no recognition of any product at 18 h treatment. Under similar conditions, SZ-21 recognized fragments at 80, 75 and 55 kDa with the 55kDa species persisting even after 18 h trypsin treatment. These studies confirm the epitopes recognised by PM6/13 and SZ-21 to be distinct and that PM6/13 represents a useful tool to differentiate the characteristics of fibrinogen and fibronectin binding to the GPIIb-IIIa complex on activated platelets.

Although many human major histocompatibility genes have been identified, relatively few have been localized to the class I region. We searched for new class I region genes by sample sequencing, a process in which short stretches of random genomic sequence are generated from cosmids and then compared with sequences deposited in nucleotide databases. Four class I region cosmids were isolated for sample sequencing by screening a chromosome 6 specific cosmid library with probes derived from specific class I region genes or with overlapping class I region yeast artificial chromosomes. Cosmids were sonnicated to produce fragments of 0.5 - 1 kilobases, subcloned, and sequenced using an automated sequencer. Sequences were then compared with nucleotide sequences deposited in the GenBank databases using the BLASTN algorithm. A number of potential new class I region genes were identified, including a cDNA with similarity to the tre oncogene, the trans-activating factor SC1 (TCF19), and a member of the interferon inducible 1 - 8 gene family. These observations suggest that sample sequencing is an efficient method for identifying new class I region genes, which can be applied to other regions of the genome and to other species, and support previous observations that the class I region contains a variety of genes other than those encoding HLA antigens.

We studied the relationship between osteolysis and polyethylene wear, age at surgery, body mass index and height in 463 subjects (180 osteolysis and 283 controls) after cemented Charnley total hip arthroplasty (THA), in order to develop a kernel-based Bayesian model to quantitate risk of osteolysis. Such tools may be integrated into decision-making algorithms to help personalize clinical decision-making. A predictive model was constructed, and the estimated posterior probability of the implant failure calculated. Annual wear provided the greatest discriminatory information. Age at surgery provided additional predictive information and was added to the model. Body mass index and height did not contain valuable discriminatory information over the range in which observations were densely sampled. The robustness and misclassification rate of the predictive model was evaluated by a five-times cross-validation method. This yielded a 70% correct predictive classification of subjects into osteolysis versus non-osteolysis groups at a mean of 11 years after THA. Finally, the data were divided into male and female subsets to further explore the relationship between wear rate, age at surgery and incidence of osteolysis. The correct classification rate using age and wear rate in the model was approximately 66% for males and 74% for females.

An experiment was conducted to compare a bunker silo sealing system comprising an oxygen barrier film (OB: 45μm thickness) with protective woven polypropylene with one comprising standard black polyethylene film (S; 125μm thickness) with protective tyres. Analysis of samples taken to 30 cm depth after 365 days of storage showed no differences in pH or lactic acid between the two sealing systems. There were no differences in aerobic bacterial count between silages. Whilst 2.56 log10 CFU moulds g-1 fresh weight were found in samples of silage sealed with S, no moulds were found in samples of silage sealed with OB. Aerobic stability, averaged 249 hours and 184 hours for OB and S, respectively. The OB system probably inhibited the development of the micro-organisms responsible for the initiation of aerobic deterioration to a greater extent than the standard silo sealing system.

A gas chromatographic (GC) assay for the determination of SCH 44643, an orally active antagonist of responses to both histamine and PAF, was developed and validated for rat plasma. The method involved organic solvent extraction followed by solid phase extraction on aminopropyl column. The separation was on a capillary column (DB-17) with quantitation by a nitrogen-phosphorus detection. The method was sensitive with a limit of quantitation of 5 ng mL−1. There was a good linear relationship between the peak height ratio (SCH 44643/internal standard) and SCH 44643 concentration in the range 5 to 200 ng mL−1. The method was precise with a coefficient of variation ranging from 1.8 to 3.0% and accurate with a bias ranging from 0 to 5.8%. Moreover, SCH 44643 was stable in rat plasma after being subjected to three freeze-thaw cycles. The assay was shown to be sensitive, specific, accurate and precise, and suitable for use in pharmacokinetic or toxicokinetic studies.

Extraction of bone contours from radiographs plays an important role in disease diagnosis, pre-operative planning, and treatment analysis. We present a fully automatic method to accurately segment the proximal femur in anteroposterior pelvic radiographs. A number of candidate positions are produced by a global search with a detector. Each is then refined using a statistical shape model together with local detectors for each model point. Both global and local models use Random Forest regression to vote for the optimal positions, leading to robust and accurate results. The performance of the system is evaluated using a set of 519 images. We show that the fully automated system is able to achieve a mean point-to-curve error of less than 1 mm for 98% of all 519 images. To the best of our knowledge, this is the most accurate automatic method for segmenting the proximal femur in radiographs yet reported.

Livestock, particularly ruminants, can eat a wider range of biomass than humans. In the drive for greater efficiency, intensive systems of livestock production have evolved to compete with humans for high-energy crops such as cereals. Feeds consumed by livestock were analysed in terms of the quantities used and efficiency of conversion of grassland, human-edible ('edible') crops and crop by-products into milk, meat and eggs, using the United Kingdom as an example of a developed livestock industry. Some 42 million tonnes of forage dry matter were consumed from 2008 to 2009 by the UK ruminant livestock population of which 0.7 was grazed pasture and 0.3 million tonnes was conserved forage. In addition, almost 13 million tonnes of raw material concentrate feeds were used in the UK animal feed industry from 2008 to 2009 of which cereal grains comprised 5.3 and soyabean meal 1.9 million tonnes. The proportion of edible feed in typical UK concentrate formulations ranged from 0.36 for milk production to 0.75 for poultry meat production. Example systems of livestock production were used to calculate feed conversion ratios (FCR - feed input per unit of fresh product). FCR for concentrate feeds was lowest for milk at 0.27 and for the meat systems ranged from 2.3 for poultry meat to 8.8 for cereal beef. Differences in FCR between systems of meat production were smaller when efficiency was calculated on an edible input/output basis, where spring-calving/grass finishing upland suckler beef and lowland lamb production were more efficient than pig and poultry meat production. With the exception of milk and upland suckler beef, FCR for edible feed protein into edible animal protein were >1.0. Edible protein/animal protein FCR of 1.0 may be possible by replacing cereal grain and soyabean meal with cereal by-products in concentrate formulations. It is concluded that by accounting for the proportions of human-edible and inedible feeds used in typical livestock production systems, a more realistic estimate of efficiency can be made for comparisons between systems.