1,088 research outputs found

    A human approach to restructuring the education system: why schools in England need social pedagogy

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    In this article, we contend that the current schools’ system in England needs to be carefully reconsidered if we are to offer opportunities for success (in its broadest sense) to those whom our current, technocratic education system excludes. With a focus on social pedagogy and human-centred learning systems, we argue that continued modifications to the existing education system are no longer sufficient and that an ideology overhaul is needed before any significant positive progress can be made. To this end, we suggest various ways that schools might work towards developing healthier and more inclusive communities, built on the key social pedagogical foundations of positive relationships, democracy, inclusion, creativity and pedagogical love. We also make recommendations for an education system in which the teacher, as a highly trained professional, can enjoy a professional autonomy commensurate with their level of qualification. Finally, we dispel some of the myths that have prevented radical, community-focused change to date

    Sodium and Specialty Cyanides Production Facility

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    Sodium cyanide and specialty cyanide production are essential operations for various industrial processes, with primary applications in mining and mineral processing. Sodium cyanide, despite the high toxicity inherent in the material and its production process, is expected to grow 5% annually, with a projected global demand of 1.1 million tonnes in 2018. This report details a process design for producing sodium cyanide through the use of two intermediate reactions and successive downstream separations. The first major step is the production of hydrogen cyanide gas from ammonia and methane derived from natural gas, via the industry standard Andrussow reaction over a platinum-rhodium gauze catalyst. Aqueous sodium cyanide is produced via a neutralization reaction of absorbed hydrogen cyanide gas with aqueous sodium hydroxide. Downstream processes include the crystallization of solid sodium cyanide from the aqueous product, with the solid product being removed from slurry and brought to low-moisture content through a series of solid-liquid separations. The low-moisture solids are formed into the final briquette product, which is 97.7% sodium cyanide by mass at a capacity of 61.5M tonnes/year, and containing sodium carbonate as the principal impurity. Unconverted ammonia is recovered and recycled back to the feed of the HCN reactor, increasing the molar percent yield of hydrogen cyanide gas on the basis of fed ammonia from 60% to 70.9%. The project requires 35.6MMinTotalCapitalInvestmentandproducesaNetPresentValueof35.6MM in Total Capital Investment and produces a Net Present Value of 72.5MM after 15 operating years and presents an Internal Rate of Return of 48.4%. The project will break even in its third operating year when it hits full production capacity. The design is recommended due to its strong return on investment and high resilience to market fluctuations

    Morphometric discrimination of two sympatric sibling species in the Palaearctic region, Culicoides obsoletus Meigen and C-scoticus Downes & Kettle (Diptera: Ceratopogonidae), vectors of bluetongue and Schmallenberg viruses

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    Background Some Palaearctic biting midge species (subgenus Avaritia) have been implicated as vectors of bluetongue virus in northern Europe. Separation of two species (C. obsoletus and C. scoticus) is considered difficult morphologically and, often, these female specimens are grouped in entomological studies. However, species-specific identification is desirable to understand their life history characteristics, assess their roles in disease transmission or measure their abundance during arboviral outbreaks. This study aims to investigate whether morphometric identification techniques can be applied to female C. obsoletus and C. scoticus individuals trapped at different geographical regions and time periods during the vector season. Methods C. obsoletus and C. scoticus were collected using light-suction traps from the UK, France and Spain, with two geographical locations sampled per country. A total of 759 C. obsoletus/C. scoticus individuals were identified using a molecular assay based on the cytochrome c oxidase subunit I gene. Fifteen morphometric measurements were taken from the head, wings and abdomen of slide-mounted specimens, and ratios calculated between these measurements. Multivariate analyses explored whether a combination of morphometric variables could lead to accurate species identification. Finally, Culicoides spp. collected in France at the start, middle and end of the adult vector season were compared, to determine whether seasonal variation exists in any of the morphometric measurements. Results The principal component analyses revealed that abdominal characteristics: length and width of the smaller and larger spermathecae, and the length of the chitinous plates and width between them, are the most reliable morphometric characteristics to differentiate between the species. Seasonal variation in the size of each species was observed for head and wing measurements, but not abdominal measurements. Geographical variation in the size of Culicoides spp. was also observed and is likely to be related to temperature at the trapping sites, with smaller individuals trapped at more southern latitudes. Conclusions Our results suggest that female C. obsoletus and C. scoticus individuals can be separated under a stereomicroscope using abdominal measurements. Although we show the length and width of the spermathecae can be used to differentiate between the species, this can be time-consuming, so we recommend undertaking this using standardized subsampling of catches. (Résumé d'auteur

    Hamilton's Turns for the Lorentz Group

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    Hamilton in the course of his studies on quaternions came up with an elegant geometric picture for the group SU(2). In this picture the group elements are represented by ``turns'', which are equivalence classes of directed great circle arcs on the unit sphere S2S^2, in such a manner that the rule for composition of group elements takes the form of the familiar parallelogram law for the Euclidean translation group. It is only recently that this construction has been generalized to the simplest noncompact group SU(1,1)=Sp(2,R)=SL(2,R)SU(1,1) = Sp(2, R) = SL(2,R), the double cover of SO(2,1). The present work develops a theory of turns for SL(2,C)SL(2,C), the double and universal cover of SO(3,1) and SO(3,C)SO(3,C), rendering a geometric representation in the spirit of Hamilton available for all low dimensional semisimple Lie groups of interest in physics. The geometric construction is illustrated through application to polar decomposition, and to the composition of Lorentz boosts and the resulting Wigner or Thomas rotation.Comment: 13 pages, Late

    On the Solutions of the Lorentz-Dirac Equation

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    We discuss the unstable character of the solutions of the Lorentz-Dirac equation and stress the need of methods like order reduction to derive a physically acceptable equation of motion. The discussion is illustrated with the paradigmatic example of the non-relativistic harmonic oscillator with radiation reaction. We also illustrate removal of the noncasual pre-acceleration with the introduction of a small correction in the Lorentz-Dirac equation.Comment: 4 eps figs. to be published in GR

    Epidemiological Characteristics of Classical Scrapie Outbreaks in 30 Sheep Flocks in the United Kingdom

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    Most previous analyses of scrapie outbreaks have focused on flocks run by research institutes, which may not reflect the field situation. Within this study, we attempt to rectify this deficit by describing the epidemiological characteristics of 30 sheep flocks naturally-infected with classical scrapie, and by exploring possible underlying causes of variation in the characteristics between flocks, including flock-level prion protein (PrP) genotype profile. In total, the study involved PrP genotype data for nearly 8600 animals and over 400 scrapie cases.We found that most scrapie cases were restricted to just two PrP genotypes (ARQ/VRQ and VRQ/VRQ), though two flocks had markedly different affected genotypes, despite having similar underlying genotype profiles to other flocks of the same breed; we identified differences amongst flocks in the age of cases of certain PrP genotypes; we found that the age-at-onset of clinical signs depended on peak incidence and flock type; we found evidence that purchasing infected animals is an important means of introducing scrapie to a flock; we found some evidence that flock-level PrP genotype profile and flock size account for variation in outbreak characteristics; identified seasonality in cases associated with lambing time in certain flocks; and we identified one case that was homozygous for phenylalanine at codon 141, a polymorphism associated with a very high risk of atypical scrapie, and 28 cases that were heterozygous at this codon.This paper presents the largest study to date on commercially-run sheep flocks naturally-infected with classical scrapie, involving 30 study flocks, more than 400 scrapie cases and over 8500 PrP genotypes. We show that some of the observed variation in epidemiological characteristics between farms is related to differences in their PrP genotype profile; although much remains unexplained and may instead be attributed to the stochastic nature of scrapie dynamics

    Epidemiological Characteristics of Classical Scrapie Outbreaks in 30 Sheep Flocks in the United Kingdom

    Get PDF
    Most previous analyses of scrapie outbreaks have focused on flocks run by research institutes, which may not reflect the field situation. Within this study, we attempt to rectify this deficit by describing the epidemiological characteristics of 30 sheep flocks naturally-infected with classical scrapie, and by exploring possible underlying causes of variation in the characteristics between flocks, including flock-level prion protein (PrP) genotype profile. In total, the study involved PrP genotype data for nearly 8600 animals and over 400 scrapie cases.We found that most scrapie cases were restricted to just two PrP genotypes (ARQ/VRQ and VRQ/VRQ), though two flocks had markedly different affected genotypes, despite having similar underlying genotype profiles to other flocks of the same breed; we identified differences amongst flocks in the age of cases of certain PrP genotypes; we found that the age-at-onset of clinical signs depended on peak incidence and flock type; we found evidence that purchasing infected animals is an important means of introducing scrapie to a flock; we found some evidence that flock-level PrP genotype profile and flock size account for variation in outbreak characteristics; identified seasonality in cases associated with lambing time in certain flocks; and we identified one case that was homozygous for phenylalanine at codon 141, a polymorphism associated with a very high risk of atypical scrapie, and 28 cases that were heterozygous at this codon.This paper presents the largest study to date on commercially-run sheep flocks naturally-infected with classical scrapie, involving 30 study flocks, more than 400 scrapie cases and over 8500 PrP genotypes. We show that some of the observed variation in epidemiological characteristics between farms is related to differences in their PrP genotype profile; although much remains unexplained and may instead be attributed to the stochastic nature of scrapie dynamics

    A robust, low- to medium-throughput prnp genotyping system in sheep

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    BACKGROUND: In many countries breeding programs for resistance to scrapie in sheep are established. Therefore, the demand on genotyping capacities of the polymorphisms of the prion protein gene (prnp) relevant to presently known disease associations and EU regulations is steadily increasing. Most published typing methods are not well suited for routine typing of large sample numbers in smaller service laboratories for different reasons: they require partly manual data processing, sophisticated and sensitive protocols, high efforts regarding time and manpower, multiple step reactions or substantial hardware investments. To overcome these drawbacks, we developed a prnp typing method that is based on a `multiplex amplification refractory mutation system' (ARMS) reaction. METHODS: In this study we combined the amplification refractory mutation system (ARMS) with standard fluorescent based fragment length analyses method to develop a prnp genotyping method (PRNP ARMS). RESULTS: By optimised primer design it was possible to type the 4 relevant single nucleotide polymorphisms (SNPs) in the prnp simultaneously in one multiplex reaction. Automated fragment length analysis enabled automated allele designation. Suitability of the PRNP ARMS for routine application was proven by typing samples with known genotypes and larger sample numbers from half-sib families. CONCLUSION: The ARMS PRNP typing method established in this study is universally suited for a broad range of typing projects with different requirements. It provides an efficient and inexpensive diagnostic mutation analysis that will improve the quality of prnp genotyping compared with other low-cost methods. It can be implemented by most molecular genetic laboratories using standard equipment

    Higher spin quaternion waves in the Klein-Gordon theory

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    Electromagnetic interactions are discussed in the context of the Klein-Gordon fermion equation. The Mott scattering amplitude is derived in leading order perturbation theory and the result of the Dirac theory is reproduced except for an overall factor of sixteen. The discrepancy is not resolved as the study points into another direction. The vertex structures involved in the scattering calculations indicate the relevance of a modified Klein-Gordon equation, which takes into account the number of polarization states of the considered quantum field. In this equation the d'Alembertian is acting on quaternion-like plane waves, which can be generalized to representations of arbitrary spin. The method provides the same relation between mass and spin that has been found previously by Majorana, Gelfand, and Yaglom in infinite spin theories
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