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Data-mining of Reaxys and network analysis of the combined literature and in-house reactions set were used to generate multiple possible reaction routes to convert a bio-waste feedstock, limonene, into a pharmaceutical API, paracetamol. The network analysis of data provides a rich knowledge-base for generation of the initial reaction screening and development programme. Based on the literature and the in-house data, an overall flowsheet for the conversion of limonene to paracetamol was proposed. Each individual reaction-separation step in the sequence was simulated as a combination of the continuous flow and batch steps. The linear model generation methodology allowed us to identify the reaction steps requiring further chemical optimisation. The generated model can be used for global optimisation and generation of environmental and other performance indicators, such as cost indicators. However, the identified further challenge is to automate model generation to evolve optimal multi-step chemical routes and optimal process configurations.

SummaryAim To understand the experiences of students and problem-based learning (PBL) facilitators during an evidence-based curriculum change to a PBL programme within an undergraduate medical course in South West England. Methods Four novel PBL cases were designed and implemented, based on educational theory and evidence. Eight focus groups were undertaken with Year-1 and -2 students (n = 18) and PBL facilitators (n = 14) to explore the experiences of participants. Thematic analysis and conceptual abstraction led to insights into the intended and unintended consequences of the change. Results Participant responses to the change process were influenced by the perceived relevance and value of the change (e.g. benefit to student learning), which was shaped by individual beliefs and preferences (e.g. presumed purpose of PBL, relative value placed on different curriculum topics, and desire for uniform educational experience), and the wider education context (e.g. expectations of assessment). It appears that the three distinct elements must align for the changes to be received positively. We updated our PBL curriculum in response to new evidence Discussion This study describes how we updated our PBL curriculum in response to new evidence, and demonstrates the importance of communicating the pedagogic rationale behind changes, and meticulous planning, preparation and alignment, even in distant parts of the curriculum. Engaging with existing views and attitudes is an essential requirement for successful curriculum change.

Unacceptable levels of adverse healthcare events, combined with changes to training, have put the spotlight on junior doctor decision-making. This study aimed to describe the decisions made by junior doctors and the contextual factors influencing how decisions were made and justified. Stimulated recall interviews with 20 junior doctors across five hospitals in SW England were undertaken to co-construct accounts of observers (researchers) and performers (junior doctors), enabling deep insights into individual capability and support needs. Decisions identified included prioritisation of patients and of tasks, and whether and when to intervene clinically. There were a surprising number of ‘inherited decisions’, made by somebody else but enacted by the junior doctor. Through their decisions, participants sought various outcomes, including impressing senior staff. Two contrasting theoretical lenses that focused on the individual decision-maker and the healthcare system enabled creative ideas about supporting e...

SUMMARYInfections by Campylobacter spp. are a major cause of gastrointestinal disease in the United Kingdom. Most cases are associated with the consumption of chicken that has become contaminated during production. We investigated the epidemiology of Campylobacter spp. in chickens in a 3-year longitudinal study of flocks reared on 30 farms in the United Kingdom. We used Generalized Linear Mixed Effect Models (GLMM) to investigate putative risk factors associated with incidence and prevalence of flock infection arising from farm and flock management and local environmental conditions during rearing. We used survival analysis to investigate infection events and associated risk factors over the course of the study using two marginal models – the independent increment approach, which assumed that individual infection events were independent; and a conditional approach, which assumed that events were conditional on those preceding. Models of flock prevalence were highly overdispersed suggesting that infection within flocks was aggregated. The key predictors of flock infection identified from the GLMM analyses were mean temperature and mean rainfall in the month of slaughter and also the presence of natural ventilation. Mean temperature in the month of slaughter was also a significant predictor of flock infection, although the analyses suggested that the risk in flocks increased in a unimodal way in relation to temperature, peaking at 12°C. The extent of pad burn was also identified as a predictor in these analyses. We conclude that predicting prevalence within flocks with linear modelling approaches is likely to be difficult, but that it may be possible to predict when flocks are at risk of Campylobacter infection. This is a key first step in managing disease and reducing the risks posed to the human food chain.

In this paper we present results on transverse mass spectra and Hanbury-Brown and Twiss correlation functions of negatively charged hadrons, which are expected to be mostly negative pions, measured in Pb-Pb collisions at 40 A GeV/c beam momentum. Based on these data, the collision dynamics and the space-time extent of the system at the thermal freeze-out are studied over a centrality range corresponding to the most central 53% of the Pb--Pb inelastic cross section. Comparisons with freeze-out conditions of strange particles and HBT results from other experiments are discussed., 29 pages, 18 figures

Results are presented on hyperon and antihyperon production in Pb-Pb, pPb and pBe collisions at 158 GeV/c per nucleon. Lambda, Xi and Omega yields have been measured at central rapidity and medium transverse momentum as functions of the centrality of the collision. Comparing the yields in Pb-Pb to those in pBe interactions, strangeness enhancement is observed. The enhancement increases with the centrality and with the strangeness content of the hyperons, reaching a factor of about 20 for the Omega in the central Pb-Pb collisions., submitted to J. Phys. G.: Nucl. Part. Phys

We present central-to-peripheral nuclear modification factors, R CP , for the p T distributions of K S 0 , Λ, Λ ¯ , and negatively charged particles, measured at central rapidity in Pb–Pb collisions at top SPS energy. The data cover the 55% most central fraction of the inelastic cross section. The K S 0 and Λ R CP ( p T ) are similar in shape to those measured at s NN = 200 GeV at RHIC, though they are larger in absolute value. We have compared our K S 0 R CP data to a theoretical calculation. The prediction overestimates the data at p T ≈ 3 – 4 GeV / c , unless sizeable parton energy loss is included in the calculation.

A measurement of strange baryon and antibaryon production in Pb-Pb collisions has been carried out by the NA57 experiment at the CERN SPS, with 40 and 158 A GeV/c beam momentum. Results on $\Lambda$, $\Xi$ and $\Omega$ hyperon yields at mid-rapidity in the most central 53% of Pb-Pb collisions at 40 A GeV/c are presented and compared with those obtained at higher energy, in the same collision centrality range. The $\Lambda$ and $\Xi^-$ yields per unit rapidity stay roughly constant while those of $\Omega^-$, $\bar\Lambda$, $\bar\Xi^+$ and $\bar\Omega^+$ increase when going to the higher SPS energy. Hyperon yields at the SPS are compared with those from the STAR experiment in $\sqrt{s_{NN}}$ = 130 GeV Au-Au collisions at RHIC., Comment: 9 pages, 4 figures, 3 tables, accepted for publication in Physics Letters B

An alternative indentation method to study materials that present a time-dependent behaviour (e. g. viscoelasticity) is the dynamic stiffness measurement technique, which provides fast and accurate values of the elastic properties through the calculation of the storage modulus (related to the elastic recovery of the material), and the loss modulus (related to the damping), using indentation cycles with oscillating load or displacement. We have made dynamic measurements on four amorphous materials (CNx, amorphous carbon, fused silica and polypropylene). Such materials have a relatively low density compared to crystalline materials of similar composition and atoms are able to move into internal free space during deformation. The results suggest that all the amorphous materials have a similar time-dependant behaviour associated with the restrictions to movement of atoms (or chains) by neighbouring atoms in the amorphous structure.

F. Antinori’, A. Bada&‘, R. Barberag, A. Belogiannia, A. Bhasine, I.J. Bloodworthe, G.E. Bruno*, S.A. Bulle, R. Caliandro*, M. Campbellh, W. Carenah, N. Carrerh, R.F. Clarkee, A. Dainese’, A.P. de Haa.9, P.C. de Rijkes, D. Di Bari*, S. Di Liberto’, R. Diviah, D. Elia*, D. Evanse, K. Fanebus@, F. Fayazzadeh”, J. Fedorisin j, G.A. Feofilov*, R.A. Fini*, P. Ganotia, B. Ghidini*, G. Grellap, H. Helstrupd, M. Henriquez”, A.K. Holmek, A. Jacholkowski*, G.T. Jonese, P. Jovanovice, A. Juskoi, R. KamermansS, J.B. Kinsone, K. Knudsonh, A.A. Kolozhvariq, V. Kondratiev ‘3, I. Kr&liki, A. KravEBkova*, P. Kuije?, V. Lenti*, R. Lietavae, G. Lovhoiden”, V. Manzari*, G. Martinskaj, M.A. MazzoniO, F. Meddi’, A. Michalonr, M. Morando’, E. Nappi*, F. Navach*, P.I. Normane, A. Palmeris, G.S. Pappalardog, B. PastirE&ki, J. Pi&, N. Pisutovaf, F. Posa*, E. Quercigh’, F. Rig@, D. RGhrich’, G. RomanoP, K. Safafikh, L. SBndo$‘, E. Schillin&, G. Segato’, M. SenCm, R. Sent?, W. Snoeysh, F. Soramel’, M. Spyropoulou-Stassinaki ‘, P. Staroba”, T.A. ToulinaQ, R. Turrisi’, T.S. Tveterk, J. Urbinj, F. Valievq, A. van den Brinks, P. van de Ven’, P. Vande Vyvreh, N. van Eijndhovens, J. van Hunenh, A. Vascottoh, T. Vik”, 0. Villalobos Bailliee, L. Vinogradovq, T. Virgil?‘, M.F. Votrubae, J. Vrlikovd and P. Zavadan

Conventional methods for analysing nanoindentation load–displacement curves to obtain mechanical properties, such as Young's modulus or hardness, require careful calibration of the indenter tip end shape and can overestimate hardness in cases where significant pile-up occurs. This paper introduces alternative methods for analysis, which are not so susceptible to such problems. Results from TiN and nickel suggest that the slopes method recently introduced by Oliver is an improvement on the other existing analysis methods.

DNA beta is an approx 1350 nucleotide, single-stranded DNA molecule which has been shown to be associated with some monopartite geminiviruses of the genus Begomovirus. This component requires the helper begomovirus for replication in the cells of host plants and for insect transmission, possibly by trans-encapsidation. Sequence comparisons of the two available DNA beta sequences has identified a highly conserved region upstream of a predicted hairpin structure. Abutting primers designed to this conserved region allows PCR-mediated amplification of the full-length DNA beta component from total nucleic acid extracts isolated from infected plants originating from a variety of geographically distinct sources and host plants.

This paper presents an experimental investigation of the effects of reverse bending and straightening process on the mechanical properties of a typical carbon steel bar used for civil engineering applications. Twenty four specimens each were used for the metallogarphy, microhardness and tensile tests. The investigation revealed that the reverse bending and straightening process has no significant effect on the bars’ through-thickness microstructure and hardness. However, the reverse bending and straightening process reduces the yield load, ultimate load, and displacement at fracture of the bars by 4.27%, 2.58%, and 18.62% respectively. These results highlight the need to take into consideration the effects of the previous loading history of the bars/wires, particularly the reduction in the displacement at fracture and consequently, the ductility of the bars/wires in the design and fitness for purpose assessment of components made from them, since the bars/wires could experience high strain during installation and in service due to overloads.

This paper combines the results from a preliminary survey of occurrence of Cryptosporidium species in faecal samples from a range of wild mammal species inhabiting mainland Britain with a tabulated literature review of world-wide reports of the parasite in those British mammals. In the literature, C. parvum was reported from 11 wild mammals found in Britain and elsewhere, mainly in rodents but also in insectivores, lagomorphs and ungulates. C. muris has been reported only in wild rodents. The sample survey detected C. parvum in seven additional British species, including carnivores. Overall, 12% of 184 faecal samples tested with a genus-specific monoclonal antibody contained oocysts of C. parvum. The results further emphasise the widespread distribution of Cryptosporidium amongst wild mammals in Britain, highlight the potential for transmission between host species and warn of the possibility of direct exposure for anybody using the countryside for professional or recreational purposes (e.g. farmers and ramblers) to previously unregarded sources of infection. It seems increasingly likely that most, if not all, mammalian species can be infected with C. parvum.

A survey of Skomer voles ( Clethrionomys glareolus skomerensis ) conducted in August of 1994 and 1995 discovered that 51% of live-trapped animals were positive for Cryptosporidium species (Coccidia). Of the positive animals, 85% were shedding C. muris in their faeces, 5% C. parvum and 10% apparently both parasite species. On the U.K. mainland, the prevalence of Cryptosporidium in the bank vole ( Clethrionomys glareolus ) is a quarter of that on Skomer and the species normally found is C. parvum . Interest in C. parvum stems from the often severe diarrhoeal disease crypt osporidiosis which it can cause in humans and livestock. The parasite occupies the gastro-intestinal tract and is transmitted between hosts by the faecal-oral route. It has been suggested that wild rodents may be an important reservoir of infection by C. parvum for livestock. However, on Skomer island, C. muris , which is rarely found in livestock, is the dominant species infecting voles.

The new results on hyperon production in Pb-Pb collisions at 158 A GeV/c and 40 A GeV/c are presented. Publisher Summary This chapter discusses the yields of hyperon in Pb–Pb collisions from the NA57 experiment. The aim of NA57 was to study the dependence of the strangeness enhancement on the interaction volume and the collision energy per incoming nucleon. The centrality range of the NA57 experiment extended down to a limit of about 50 wounded nucleons. The experiment collected data using 158 and 40 A GeV/c beams at the CERN SPS. There was indication of an increase of the enhancements with the centrality of the collisions. The data were corrected for acceptance and efficiency losses by calculating weight for each particle with a GEANT-based Monte-Carlo simulation.

A retrospective cohort analysis, using data extracted from clinical notes, examined the validity of standardized mortality ratios (SMRs) for cervical cancer as an indicator of the quality of health services by exploring the mortality at five years of patients presenting with cervical cancer, identifying factors associated with survival, and studying the relationship of those factors to SMRs for the disease. The subjects were 1038 women aged 15-64 registered at the Yorkshire Cancer Registry as having invasive cervical cancer between 1979 and 1983. It was found that independent risk factors for mortality within five years of presentation were stage at diagnosis and smoking habit. Method of treatment had an effect that failed to reach statistical significance. Independent risk factors for late stage at presentation were absence of a history of cervical smear and increasing age. Considerable variation remained unexplained in both models. District SMRs were not related to five-year survival, stage at presentation or screening history. SMRs were related to proportions of smokers. It is concluded that SMRs are subject to considerable influence from a range of unidentified factors, as well as identified risk factors. They are too broad an indicator to be a valid measure of health service performance. The health service's ability to reduce case fatality does not outweigh the effects of incidence and severity. Better indicators would be survival to five years of those presenting at stage II or less and distribution of stage at presentation.

[EN] Geographical and seasonal variation in the incidence and prevalence of Campylobacter jejuni and C. coli in housed broiler flocks reared in Great Britain in 2004 to 2006 was investigated in this study. Ceca (30) from 797 flocks, not subject to prior partial depopulation and reared on 211 farms, were examined individually for the presence of Campylobacter spp. The best-fitting climatic factors explained approximately 46% of the prevalence of Campylobacter-colonized flocks at slaughter and consisted of a combination of temperature at slaughter, number of sunshine hours in placement month, and millimeters of rainfall in placement month. Positive flocks were more likely to be slaughtered between June and November than during the rest of the year and to be reared in northern Great Britain than in central or southern Great Britain. C. jejuni was identified in approximately 90% of flocks, and C. coli was present in 10% of flocks. The most common clonal complexes identified in 226 isolates typed by multilocus sequence typing (MLST) were ST-45, ST-21, ST-574, ST-443, and ST-828. Flocks slaughtered at the same time were more likely to have similar complexes, and ST-45 had a seasonal pattern, with the highest prevalence in June, and was also more likely to be present in flocks reared in northern Great Britain. © 2011, American Society for Microbiology., This work was supported by the UK Food Standards Agency (project code B15001) and by the Health Protection Agency.

We describe two methods for the optimization of gas transmission networks. The first method reduces the number of variables in the optimization problem by eliminating the pipe-flow variables. The second method solves an optimization problem with the full set of variables to achieve better behaviour. These two methods are compared by a series of tests based on the British Gas NTS (National Transmission System). The results of these tests are reported. By formulating the network problem as an optimization problem we have been able to replace heuristics by well proven methods. The reliability of the algorithm using the reduced set of unknowns varied depending on the size of problem and the type of objective function being minimized. The algorithm using the full set of unknowns had no such difficulties, even though it needs to be used with some care. The algorithm is robust in the sense that when the objective function has the necessary continuities, there is a feasible point and the penalty terms ensure positive curvature, then a solution is found reliably. The algorithm based on the reduced set of unknowns is considerably faster than that using the full set, when it succeeds. The factor between the times taken ranges from 1.2 to 5 (average 3) for the smallest network. For the second case comparison is harder since the reduced set algorithm was given a head start in five cases. For the other five the factor is between 2.3 and 8.3. For the largest problem there is just one case in which the comparison is on equal terms, and here the factor is 18. It is clear that the reliability of the full set algorithm is bought at a considerable cost which rises as the problem gets bigger. The main conclusion is that the Sequential Augmented Lagrange Method yields a reliable algorithm for minimizing objective functions of practical interest based on gas networks such as the British Gas National Transmission System. It is not satisfactory to carry over to the case with machines techniques like those of the nodal and loop methods which work well on networks with no machines.

7-Hydroxy-1, 8-cineole (3a) and the corresponding carboxylic acid (3b) have been isolated from the urine of brushtail possums (Trichosurus vulpecula: Marsupialia) fed a diet enhanced with 1, 8-cineole. Chemical syntheses of these two novel metabolites are described.

A synthesis of the avocado antifungal, (Z,Z)-2-hydroxy-4-oxohenicosa-12,15-dien-1-yl acetate (1a), confirms the structure of the compound as isolated from both avocado fruit and leaves, and provides the absolute configuration of the natural lipid.

Rates of homogeneous nucleation of ice in micrometre-sized water droplets are reported. Measurements were made using a new system in which droplets were supported on a hydrophobic substrate and their phase was monitored using optical microscopy as they were cooled at a controlled rate. Our nucleation rates are in agreement, given the quoted uncertainties, with the most recent literature data. However, the level of uncertainty in the rate of homogeneous freezing remains unacceptable given the importance of homogeneous nucleation to cloud formation in the Earth's atmosphere. We go on to use the most recent thermodynamic data for cubic ice (the metastable phase thought to nucleate from supercooled water) to estimate the interfacial energy of the cubic ice-supercooled water interface. We estimate a value of 20.8 +/- 1.2 mJ m(-2) in the temperature range 234.9-236.7 K.

This review aimed to determine the availability of core curricula for the biomedical sciences in the published literature and the approach taken to determining learning objectives. A systematic review was conducted searching three databases for articles containing the terms 'core curriculum', 'undergraduate' and 'medic*'. Fifty seven papers were read in full, of which 40 listed learning objectives. The authors used a consensus process to categorize the learning objectives according to the level of detail (high / medium / low) and the approach taken (either a top down approach using experts or a bottom up approach using key stakeholders). This paper directs the reader to publications that describe core curricula for the biomedical sciences. The review revealed that topic coverage was patchy and there was a variable level of detail of learning outcomes presented. Documents published by professional bodies tended to provide more detailed learning outcomes than those derived by experts associated with medical schools. Two thirds of the 40 publications used a top down approach and there was a temporal trend towards involving non-expert groups in some stage of the process of defining the learning objectives, regardless of whether a top down or bottom up approach was taken.

We investigated the associations between Campylobacter colonisation and management practices and farm characteristics in 603 housed broiler batches originating from 137 farms in Great Britain. All study batches were the initial batch slaughtered from the selected house on enrolled farms. Between 1 and 15 batches were sampled from each farm throughout the study. A total of 34.2% of the batches was Campylobacter positive and multivariable multilevel logistic regression revealed that the risk of Campylobacter colonisation was highest in July (OR=3.4, CI95%:1.8; 6.4), August (OR=3.4, CI95%:1.9; 6.2) and September (OR=3.7, CI95%:1.9; 7.1). Cattle on or adjacent to the farm increased the risk (OR=1.7, CI95%:1.1; 2.7), whereas chlorinated drinking water reduced it (OR=0.5, CI95%:0.2; 0.9). If the first removed batch from the previous flock in the house had been Campylobacter positive, the first batch of the following flock was also more likely to be colonised (OR=3.2, CI95%:2.1; 4.9). This association was more likely due to a persistent risk practice or source of Campylobacter on the farm than a direct carry-over from previous flock.

This study investigated the relationship between flock health and Campylobacter infection of housed commercial broilers in Great Britain. Thirty ceca were collected at slaughter from batches of broilers from 789 flocks, at either full or partial depopulation, between December 2003 and March 2006 and examined individually for Campylobacter by direct plating onto selective media. Management and health data were collected from each flock and included information on mortality or culling during rearing, the number of birds rejected for infectious or noninfectious causes at slaughter, the proportion of birds with digital dermatitis (also termed hock burn), and other general characteristics of the flock. Campylobacter spp. were isolated from 280 (35%) flocks. The relationship between bird health and welfare and Campylobacter status of flocks was assessed using random-effects logistic regression models, adjusting for region, month, year, and rearing regime. Campylobacter -positive batches of ceca were associated with higher levels of rejection due to infection (odds ratio [OR], 1.5; 95% confidence interval [CI 95% ], 0.98 to 2.30) and digital dermatitis (OR, 2.08; CI 95% , 1.20 to 3.61). Furthermore, higher levels of these conditions were also associated with the highest-level category of within-flock Campylobacter prevalence (70 to 100%). These results could indicate that improving health and welfare may also reduce Campylobacter in broilers.

The study aimed to identify sources of campylobacter in 10 housed broiler flocks from three United Kingdom poultry companies. Samples from (i) the breeder flocks, which supplied the broilers, (ii) cleaned and disinfected houses prior to chick placement, (iii) the chickens, and (iv) the environments inside and outside the broiler houses during rearing were examined. Samples were collected at frequent intervals and examined for Campylobacter spp. Characterization of the isolates using multilocus sequence typing (MLST), serotyping, phage typing, and flaA restriction fragment length polymorphism typing was performed. Seven flocks became colonized during the growing period. Campylobacter spp. were detected in the environment surrounding the broiler house, prior to as well as during flock colonization, for six of these flocks. On two occasions, isolates detected in a puddle just prior to the birds being placed were indistinguishable from those colonizing the birds. Once flocks were colonized, indistinguishable strains of campylobacter were found in the feed and water and in the air of the broiler house. Campylobacter spp. were also detected in the air up to 30 m downstream of the broiler house, which raises the issue of the role of airborne transmission in the spread of campylobacter. At any time during rearing, broiler flocks were colonized by only one or two types determined by MLST but these changed, with some strains superseding others. In conclusion, the study provided strong evidence for the environment as a source of campylobacters colonizing housed broiler flocks. It also demonstrated colonization by successive campylobacter types determined by MLST during the life of a flock.

The transverse mass spectra of K0s, Lambda, Xi and Omega particles produced in Pb-Pb collisions at 40 A GeV/c have been studied for a sample of events corresponding to the most central 53% of the inelastic Pb-Pb cross-section. We analyze the distributions in the framework of a parameterized model inspired by hydrodynamics. The dependence of the freeze-out parameters on particle species and event centrality is discussed and comparisons with results at higher energy are shown., Comment: submitted to Journal Of Physics G: Nuclear And Particle Physics

The presence and numbers of campylobacters on chicken carcasses from 26 slaughter groups, originating from 22 single-house flocks and processed in four UK plants, were studied in relation to the level of flock colonisation determined by examining the caecal contents of at least ten birds per group. The prevalence of campylobacters on carcasses from five campylobacter-negative flocks processed just after other negative flocks was low (/=30%). Campylobacters were isolated from 90 to 100% of carcasses from three flocks which were partly colonised, with 5, 5 and 30% of caecal contents positive, and which were processed after fully colonised flocks. All carcasses from the remaining fully colonised flocks were contaminated with campylobacters, and they had significantly (P0.001) higher numbers per carcass (average of 5.3 log(10) cfu; range: 1.3 to8.0 log(10) cfu) than carcasses originating from low prevalence flocks (average of 2.3 log(10) cfu; range:1.1 to 4.1 log(10) cfu). There was a reduction in the numbers of campylobacters on carcasses between plucking and chilling in eight of ten fully colonised flocks. In another eight flocks, a significant (P0.001) decrease (0.8 log(10) cfu) in the number of campylobacters on carcasses from just before to after chilling was detected. Campylobacter spp. could be isolated from aerosols, particles and droplets in considerable numbers in the hanging-on, defeathering and evisceration areas but not in the chillers. This was the case even when campylobacters were not isolated from the target flock. Campylobacters on carcasses from two partly colonised flocks were either the same subtype, as determined by speciation, Multi-Locus Sequence Typing (MLST) and flaA Restricted Fragment Length Polymorphism (RFLP) typing, as those in the fully colonised flocks processed previously, although not necessarily the most prevalent ones; or were the same subtypes as those found in the caeca of the flock itself. The prevalences of the different campylobacter subtypes found on carcasses from two fully colonised flocks did not closely reflect those found in the caeca. MLST combined with flaA RFLP provided a good method for ascertaining the relatedness of strains isolated from carcasses and caecal contents. This study showed that carcass contamination is related to the within-flock prevalence of campylobacter colonisation, but that contamination from previously processed flocks was also significant, especially on carcasses from low prevalence flocks. Forced dry air cooling of carcasses reduced contamination levels.

The NA57 experiment has measured the production of strange and multi-strange hadrons in heavy-ion collisions at the CERN SPS. After briefly introducing the NA57 apparatus and analysis procedures, we present recent results on strangeness enhancement in Pb-Pb relative to $\textrm{p}$-Be collisions, on the study of the $m_{T}$ distributions of strange particles, and on central-to-peripheral nuclear modification factors in Pb-Pb collisions at top SPS energy. The NA57 experiment has measured the production of strange and multi-strange hadrons in heavy-ion collisions at the CERN SPS. After briefly introducing the NA57 apparatus and analysis procedures, we present recent results on strangeness enhancement in Pb-Pb relative to p-Be collisions, on the study of the m_T distributions of strange particles, and on central-to-peripheral nuclear modification factors in Pb-Pb collisions at top SPS energy. The NA57 experiment has measured the production of strange and multi-strange hadrons in heavy-ion collisions at the CERN SPS. After briefly introducing the NA57 apparatus and analysis procedures, we present recent results on strangeness enhancement in Pb+Pb relative to p+Be collisions, on the study of the m T distributions of strange particles, and on central-to-peripheral nuclear modification factors in Pb+Pb collisions at top SPS energy.

The multiplicity of charged particles in the central rapidity region has been measured by the NA57 experiment in Pb--Pb collisions at the CERN SPS at two beam momenta: 158 A GeV/{\it c} and 40 A GeV/{\it c}. The value of $dN_{ch}/d\eta$ at the maximum has been determined and its behaviour as a function of centrality has been studied in the centrality range covered by NA57 (about 50% of the inelastic cross section). The multiplicity increases approximately logarithmically with the centre of mass energy., Comment: 19 pages, 8 figures

We study the transverse polarization of Λ’s and Ω−’s produced in Pb + Pb interaction at 160 A GeV/c. We also present a study of the longitudinal polarization of Λ’s produced in the weak decays of Ξ’s.

Enhancements of strange baryon and anti-baryon yields were first observed in Pb–Pb interactions at 160 A GeV/c by WA97. The aim of the NA57 experiment is to investigate how these enhancements behave as a function of energy, and over a broader centrality range than that which was available with WA97. This paper presents a comparison of the hyperon yields in Pb–Pb interactions at 40 A GeV/c and 160 A GeV/c. Preliminary signals for the p-Be data at 40 A GeV/c are also shown.

The NA57 experiment has measured strange baryon and antibaryon production in Pb-Pb collisions at 40 A GeV/c and 160 A GeV/c beam momenta. This presentation covers strangeness enhancement and transverse spectra from the 160 A GeV/c data, and energy dependence of the particle yields. Enhancement factors increase with increasing strangeness content of the particle, when production yields from Pb-Pb collisions are compared with those observed in p-Be and p-Pb interactions. The transverse mass spectra have been analysed both with exponential fits and using a transverse flow model.

The NA57 experiment has been designed to study the onset of the strange baryon and antibaryon enhancements in Pb Pb with respect to p-Be collisions, first observed by WA97 at 160 A GeV/ c . NA57 has extended the WA97 measurements to investigate the evolution of strangeness enhancement over a wider centrality range and as a function of the beam energy. Results on hyperon production in central Pb Pb collisions at 40 A GeV/ c are presented and compared with those obtained at higher energy, in the same centrality range.

The production of strange baryons and anti‐baryons in PbPb and pBe collisions has been studied by the NA57 experiment at the CERN SPS, extending down the centrality range covered by the previous WA97 experiment, and collecting data at two different energies. The enhanced production of such particles in central PbPb collisions with respect to pBe has been experimentally confirmed. This paper discusses results on Ⅺ and Λ hyperon production obtained at 40 and 158 A GeV/c.

The NA57 experiment has been designed to study the onset of enhanced production of strange baryons and anti-baryons in Pb-Pb collisions with respect to p-Be collisions. Results from 40 and 160 A GeV/c Pb-Pb data will be shown. The main focus is on the checks of the NA57 analysis chain.

The recent development of simple, rapid genotyping techniques for Campylobacter species has enabled investigation of the determinative epidemiology of these organisms in a variety of situations. In this study we have used the technique of fla typing (PCR-restriction fragment length polymorphism analysis of the flaA and flaB genes) to identify the sources of strains contaminating the carcasses of five campylobacter-positive and two campylobacter-negative broiler flocks during abattoir processing. The results confirmed that, in the United Kingdom, individual broiler flocks are colonized by a limited number of subtypes of Campylobacter jejuni or C. coli . In some but not all cases, the same subtypes, isolated from the ceca, contaminated the end product as observed in carcass washes. However, the culture methodology, i.e, use of direct plating or enrichment, affected this subtype distribution. Moreover, the number of isolates analyzed per sample was limited. fla typing also indicated that some campylobacter subtypes survive poultry processing better than others. The extent of resistance to the environmental stresses during processing varied between strains. The more robust subtypes appeared to contaminate the abattoir environment, surviving through carcass chilling, and even carrying over onto subsequent flocks. From these studies it is confirmed that some campylobacter-negative flocks reach the abattoir but the carcasses from such flocks are rapidly contaminated by various campylobacter subtypes during processing. However, only some of these contaminating subtypes appeared to survive processing. The sources of this contamination are not clear, but in both negative flocks, campylobacters of the same subtypes as those recovered from the carcasses were isolated from the crates used to transport the birds. In one case, this crate contamination was shown to be present before the birds were loaded.

In genetic epidemiologic studies, investigators often use generalized linear models to evaluate the relationships between a disease trait and covariates, such as one or more candidate genes or an environmental exposure. Recently, attention has turned to study designs that mandate the inclusion of family members in addition to a proband. Standard models for analysis assume independent observations, which is unlikely to be true for family data, and the usual standard errors for the regression parameter estimates may be too large or too small, depending on the distribution of the covariates within and between families. The consequences of familial correlation on the study efficiency can be measured by a design effect that is equivalent to the relative information in a sample of unrelated individuals compared to a sample of families with the same number of individuals. We examine design effects for studies in association, and illustrate how the design effect is influenced by the intra-familial distribution of covariate values such as would be expected for a candidate gene. Typical design effects for a candidate gene range between 1.1 and 2.4, depending on the size of the family and the amount of unexplained familial correlation. These values correspond to a modest 10% increase in the required sample size up to more than doubling the requirements. Design effect values are useful in study design to compare the efficiency of studies that sample families versus independent individuals and to determine sample size requirements that account for familial correlation.

PoS(hep2001)248; New data on strange baryon yields in Pb–Pb interactions at 158 GeV/c per nucleon are presented as a function of the collision centrality. The possible onset of a deconfined phase when the collision involves from 50 to 100 wounded nucleons is discussed.

NA57 has been specifically designed to study the onset of strange baryon and antibaryon enhancements in Pb-Pb with respect to p-Be collisions, first observed by the WA97 experiment at 160 A GeV/c beam momentum. The aim is to look for the dependence of these enhancements on the interaction volume, as measured by the number of wounded nucleons, and the energy per incoming nucleon. In NA57 the centrality range goes down to a lower limit of about 50 wounded nucleons, compared with about 100 in WA97. Data have been collected both at 160 and at 40 A GeV/c, while WA97 collected data only at the top SPS beam momentum of 160 A GeV/c. In this contribution we recall the main features of the NA57 experiment and we present the first results on Ⅺ− and Ⅺ+ hyperon production in Pb-Pb collisions at 160 A GeV/c.

We applied generalized transmission disequilibrium testing (TDT) models in combined replicates 1 through 5 from each of four simulated population samples. All analyses were conducted without knowledge of the generating models. To assess power and consistency of results within and between samples, analyses were repeated in all 25 replicates combined and in each replicate. With the exception of sample-specific findings for locus D, power was generally low to detect linkage in a genome scan or to confirm linkages detected by allele sharing in affected relatives, due to lack of linkage disequilibrium. We proposed likelihood ratio and Wald tests to detect heterogeneity among samples in disease-marker associations. Pooling data across heterogeneous populations may not improve power of the TDT method.

The potential of Norway rats (Rattus norvegicus) to spread the parasite Cryptosporidium parvum was investigated by examining parasite prevalence in relation to the structure and movements of three permanent rat populations living on farmland in Warwickshire (UK) from October 1994 to March 1997. One population lived among a group of farm buildings housing cattle, while the other two had no contact with livestock, one living around a pond and its outflowing stream and the other on a rubbish tip. Overall, parasite occurrence was 24% (n = 438), but it varied according to body weight (age) with 40% of juveniles (or =100 g) infected decreasing to 12% for adults400 g, suggesting that actively breeding populations are potentially more likely to spread the parasite than non-breeding populations. There was no difference in prevalence between the three populations. The parasite was detected in more males (29%) than females (19%). Seasonally, on the livestock farm, prevalence was significantly lower in autumn (10%), but varied little (31-36%) from winter to summer. In contrast, on the arable farm, prevalence peaked in summer (50%) with a trough in winter (6%). Infection in rats appeared to last67 days. Rats living on the livestock farm had home ranges largely confined to the cattle sheds, thereby maintaining a potential source of infection for livestock if rodent control was not part of a decontamination program. Equally, rats living around the pond on the arable farm provided a source of oocysts to contaminate the pond water, as well as being able to carry the parasite to nearby farm buildings or even to neighboring farms.