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

Analysis of energy gap opening in graphene oxide

The utilisation of graphene structures as photonics materials mandates that an optically active electronic energy gap be formed. Opening of a gap in graphene has been demonstrated by functionalisation with H, F, or O atoms, while experimental observations of graphene oxide have hinted at interesting optical properties, with the potential for absorption of visible light. As such, our analysis is focused on O functionalisation of graphene. We present results from extensive ab initio and hybrid DFT calculations, demonstrating the creation of an optically active gap

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

Type I interferon is required for T helper (Th) 2 induction by dendritic cells

Type 2 inflammation is a defining feature of infection with parasitic worms (helminths), as well as being responsible for widespread suffering in allergies. However, the precise mechanisms involved in T helper (Th) 2 polarization by dendritic cells (DCs) are currently unclear. We have identified a previously unrecognized role for type I IFN (IFN-I) in enabling this process. An IFN-I signature was evident in DCs responding to the helminth Schistosoma mansoni or the allergen house dust mite (HDM). Further, IFN-I signaling was required for optimal DC phenotypic activation in response to helminth antigen (Ag), and efficient migration to, and localization with, T cells in the draining lymph node (dLN). Importantly, DCs generated from Ifnar1-/- mice were incapable of initiating Th2 responses in vivo. These data demonstrate for the first time that the influence of IFN-I is not limited to antiviral or bacterial settings but also has a central role to play in DC initiation of Th2 responses

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

'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

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.

CD8+ T cells from a novel T cell receptor transgenic mouse induce liver-stage immunity that can be boosted by blood-stage infection in rodent malaria

To follow the fate of CD8+ T cells responsive to Plasmodium berghei ANKA (PbA) infection, we generated an MHC I-restricted TCR transgenic mouse line against this pathogen. T cells from this line, termed PbT-I T cells, were able to respond to blood-stage infection by PbA and two other rodent malaria species, P. yoelii XNL and P. chabaudi AS. These PbT-I T cells were also able to respond to sporozoites and to protect mice from liver-stage infection. Examination of the requirements for priming after intravenous administration of irradiated sporozoites, an effective vaccination approach, showed that the spleen rather than the liver was the main site of priming and that responses depended on CD8α+ dendritic cells. Importantly, sequential exposure to irradiated sporozoites followed two days later by blood-stage infection led to augmented PbT-I T cell expansion. These findings indicate that PbT-I T cells are a highly versatile tool for studying multiple stages and species of rodent malaria and suggest that cross-stage reactive CD8+ T cells may be utilized in liver-stage vaccine design to enable boosting by blood-stage infections