Inelastic neutron scattering studies of methyl chloride synthesis over alumina

Not only is alumina the most widely used catalyst support material in the world, it is also an important catalyst in its own right. One major chemical process that uses alumina in this respect is the industrial production of methyl chloride. This is a large scale process (650 000 metric tons in 2010 in the United States), and a key feedstock in the production of silicones that are widely used as household sealants. In this Account, we show how, in partnership with conventional spectroscopic and reaction testing methods, inelastic neutron scattering (INS) spectroscopy can provide additional insight into the active sites present on the catalyst, as well as the intermediates present on the catalyst surface.<p></p> INS spectroscopy is a form of vibrational spectroscopy, where the spectral features are dominated by modes involving hydrogen. Because of this, most materials including alumina are largely transparent to neutrons. Advantageously, in this technique, the entire “mid-infrared”, 0–4000 cm<sup>–1</sup>, range is accessible; there is no cut-off at 1400 cm<sup>–1</sup> as in infrared spectroscopy. It is also straightforward to distinguish fundamental modes from overtones and combinations. <p></p> A key parameter in the catalyst’s activity is the surface acidity. In infrared spectroscopy of adsorbed pyridine, the shifts in the ring stretching modes are dependent on the strength of the acid site. However, there is a very limited spectral range available. We discuss how we can observe the low energy ring deformation modes of adsorbed pyridine by INS spectroscopy. These modes can undergo shifts that are as large as those seen with infrared inspectroscopy, potentially enabling finer discrimination between acid sites. <p></p> Surface hydroxyls play a key role in alumina catalysis, but in infrared spectroscopy, the presence of electrical anharmonicity complicates the interpretation of the O–H stretch region. In addition, the deformations lie below the infrared cut-off. Both of these limitations are irrelevant to INS spectroscopy, and all the modes are readily observable. When we add HCl to the catalyst surface, the acid causes changes in the spectra. We can then deduce both that the surface chlorination leads to enhanced Lewis acidity and that the hydroxyl group must be threefold coordinated. <p></p> When we react η-alumina with methanol, the catalyst forms a chemisorbed methoxy species. Infrared spectroscopy clearly shows its presence but also indicates the possible coexistence of a second species. Because of INS spectroscopy’s ability to discriminate between fundamental modes and combinations, we were able to unambiguously show that there is a single intermediate present on the surface of the active catalyst. This work represents a clear example where an understanding of the chemistry at the molecular level can help rationalize improvements in a large scale industrial process with both financial and environmental benefits. <p></p&gt

The Givenness of the Human Learning Experience and Its Incompatibility with Information Analytics

The rise of learning analytics, the application of complex metrics developed to exploit the proliferation of ‘Big Data’ in educational work, raises important moral questions about the nature of what is measurable in education. Teachers, schools and nations are increasingly held to account based on metrics, exacerbating the tendency for fine-grained measurement of learning experiences. In this article, the origins of learning analytics ontology are explored, drawing upon core ideas in the philosophy of computing, such as the general definition of information and the information-theoretic account of knowledge. Drawing upon a reading of Descartes Meditatio II, which extends the phenomenology of Jean-Luc Marion into a pedagogy of intentionality, the article identifies a fundamental incompatibility between the subjective experience of learning and the information-theoretic account of knowledge. Human subjects experience and value their own information incommensurably with the ways in which computers measure and quantify information. The consequences of this finding for the design of online learning environments, and the necessary limitations of learning analytics and measurement are explored

Balancing securitisation and education in schools: teachers' agency in implementing the Prevent duty

Since the introduction of the Prevent duty across the UK, schools have had to balance the need to fulfil their responsibilities under the duty – often understood to include monitoring and surveillance – with their ultimate purpose to educate their students. This positions teachers within a particular set of tensions about their own beliefs about education, their values, and their roles and relationships with young people and communities. This paper draws on interviews with classroom teachers and members of school leadership teams from ten schools, in order to compare how teachers have understood and responded to those tensions. The paper will focus on the various ways in which teachers frame the policy, and the ways in which they exercise agency in their responses. Drawing on an ecological approach to theorising teacher agency our data reveals how teachers develop different responses to anti-extremism policy depending on their role; their school contexts; and their own beliefs. Whilst in some important regards the statutory Prevent duty has ‘closed down’ some options, nevertheless teachers exercise agency to interpret and enact policy and, when translating the policy into a curriculum context, also make ‘leaps’ of interpretation as concepts such as fundamental British values are turned into lessons. Our analysis highlights how teacher agency helps to account for the variations in implementation and also opens up new avenues for investigating and critiquing anti-extremism policy in education

A theory of motivation and ontological enhancement: the role of disability policy in student empowerment and institutional change

As debate continues around the nature and values of education, it is important to ask the question of what factors motivate a student to engage with the ends of an educational institution. In this paper, a broad, holistic view of learner motivation, derived from Aristotelian ethics, is used to provide a model to drive institutional change. Focussing on the approach of one Higher Education institution to the particular accommodations required for students with disabilities, the paper identifies three factors which motivate students, a failure to engage with the aims and ends of the educational project, a failure to see that a particular learning aim is worth attaining, and a simple lack of will‐power to attain it. To each of these failures a social cause is identified, and a change in both the institutional culture and the individual learner's approach to their education is suggested

Authority, Autonomy and Automation: The Irreducibility of Pedagogy to Information Transactions

"This paper draws attention to the tendency of a range of technologies to reduce pedagogical interactions to a series of datafied transactions of information. This is problematic because such transactions are always by definition reducible to finite possibilities. As the ability to gather and analyse data becomes increasingly fine-grained, the threat that these datafied approaches over-determine the pedagogical space increases. Drawing on the work of Hegel, as interpreted by 20th century French radical philosopher Alexandre Kojève, this paper develops a model of relational pedagogy which highlights three points of incompatibility with a datafied learning environment reduced to finite measures. Firstly: Kojève’s accont of authority in Hegel posits two aspects to the mimetic relation between teacher and student: recognition and realisation, which belong to the ipseity or about-self-ness of the subject, and are incompatible with a general definition of data. Secondly, the Hegelian approach to human historical time, in particular the assertion that time and desire are begun in the future, not the past, renders it incompatible with mathematical time as used in data processing. Finally, from these it is possible to derive a distinctive notion of the work of pedagogy, grounded in Kojève’s realist reading of Hegel, irreducible to information processing. In consequence of this threefold irreducibility, the paper draws attention to a need for relations of human pedagogical work to be inherent in the design of educational technologies and highlights the dangers of presuming a machine intelligence model in the design of learning environments.

'Respect Study' the Treatment of Religious Difference and Otherness: An ethnographic investigation in UK schools

Understanding and appreciating the beliefs and practices of others feature prominently among the aims and purposes of Religious Education in UK schools. Drawing on ethnographic data from the ‘Does RE Work?’ project, this paper presents two conceptions if ‘in/entoleration’ a deliberate process of inculcating tolerance in pedagogy. Entoleration, akin to enculturation, encourages sympathetic and transformative encounter with others’ beliefs. Intoleration, akin to indoctrination, risks eliding both difference and encounter in the service of a pre-determined aim of nurturing uncritical tolerance. The former is categorised by pedagogies of encounter with the other as person, while the latter often focuses on externals and strangeness

IP-10-Mediated T Cell Homing Promotes Cerebral Inflammation over Splenic Immunity to Malaria Infection

Plasmodium falciparum malaria causes 660 million clinical cases with over 2 million deaths each year. Acquired host immunity limits the clinical impact of malaria infection and provides protection against parasite replication. Experimental evidence indicates that cell-mediated immune responses also result in detrimental inflammation and contribute to severe disease induction. In both humans and mice, the spleen is a crucial organ involved in blood stage malaria clearance, while organ-specific disease appears to be associated with sequestration of parasitized erythrocytes in vascular beds and subsequent recruitment of inflammatory leukocytes. Using a rodent model of cerebral malaria, we have previously found that the majority of T lymphocytes in intravascular infiltrates of cerebral malaria-affected mice express the chemokine receptor CXCR3. Here we investigated the effect of IP-10 blockade in the development of experimental cerebral malaria and the induction of splenic anti-parasite immunity. We found that specific neutralization of IP-10 over the course of infection and genetic deletion of this chemokine in knockout mice reduces cerebral intravascular inflammation and is sufficient to protect P. berghei ANKA-infected mice from fatality. Furthermore, our results demonstrate that lack of IP-10 during infection significantly reduces peripheral parasitemia. The increased resistance to infection observed in the absence of IP-10-mediated cell trafficking was associated with retention and subsequent expansion of parasite-specific T cells in spleens of infected animals, which appears to be advantageous for the control of parasite burden. Thus, our results demonstrate that modulating homing of cellular immune responses to malaria is critical for reaching a balance between protective immunity and immunopathogenesis

Building a Terrorist House on Sand: A critical incident analysis of interprofessionality and the Prevent duty in schools in England.

In 2015, a duty came into effect requiring all public bodies, including schools, to engage with the UK government’s Prevent counter-terrorism strategy. This paper presents two case studies from mid-size English cities, exploring the moral prototypes and institutional identities of professional mediators who made schools aware of their duties under Prevent. Mediators in each case included serving and former police, teachers and policy advisers, the majority of whom are now private consultants or operating small 3rd sector agencies. Drawing from in-depth interviews with 14 professionals, the paper details the ways in which participants constructed their relationship to normative, deliberative and legal obligations. The paper focuses on the recurrence of a high profile critical media incident in which a young child was allegedly subject to a referral for writing about living in a ‘terrorist’ (rather than ‘terraced’) house. Reaction to this incident was archetypal of the fear of media moral panic in reconstituting mediators’ identities as Prevent professionals, illustrating how the enframing of events shifts professional moral codes, policy interpretation and implementation

Opsonising antibodies to P. falciparum Merozoites associated with immunity to clinical malaria

Naturally acquired humoral immunity to the malarial parasite Plasmodium falciparum can protect against disease, although the precise mechanisms remain unclear. Although antibody levels can be measured by ELISA, few studies have investigated functional antibody assays in relation to clinical outcomes. In this study we applied a recently developed functional assay of antibody-mediated opsonisation of merozoites, to plasma samples from a longitudinal cohort study conducted in a malaria endemic region of Papua New Guinea (PNG). Phagocytic activity was quantified by flow cytometry using a standardized and high-throughput protocol, and was subsequently evaluated for association with protection from clinical malaria and high-density parasitemia. Opsonising antibody responses were found to: i) increase with age, ii) be enhanced by concurrent infection, and iii) correlate with protection from clinical episodes and high-density parasitemia. Stronger protective associations were observed in individuals with no detectable parasitemia at baseline. This study presents the first evidence for merozoite phagocytosis as a correlate of acquired immunity and clinical protection against P. falciparum malaria

CD4+ Natural Regulatory T Cells Prevent Experimental Cerebral Malaria via CTLA-4 When Expanded In Vivo

Studies in malaria patients indicate that higher frequencies of peripheral blood CD4+ Foxp3+ CD25+ regulatory T (Treg) cells correlate with increased blood parasitemia. This observation implies that Treg cells impair pathogen clearance and thus may be detrimental to the host during infection. In C57BL/6 mice infected with Plasmodium berghei ANKA, depletion of Foxp3+ cells did not improve parasite control or disease outcome. In contrast, elevating frequencies of natural Treg cells in vivo using IL-2/anti-IL-2 complexes resulted in complete protection against severe disease. This protection was entirely dependent upon Foxp3+ cells and resulted in lower parasite biomass, impaired antigen-specific CD4+ T and CD8+ T cell responses that would normally promote parasite tissue sequestration in this model, and reduced recruitment of conventional T cells to the brain. Furthermore, Foxp3+ cell-mediated protection was dependent upon CTLA-4 but not IL-10. These data show that T cell-mediated parasite tissue sequestration can be reduced by regulatory T cells in a mouse model of malaria, thereby limiting malaria-induced immune pathology