Structural and analytical studies by tandem mass spectrometry

This thesis describes the use of several such tandem mass spectrometrical techniques, the majority including controlled collisions with a target gas to effect dissociation or charge exchange. A range of MS/MS techniques was utilized in the study of the fragmentation of [M-CO]+. ions from various positional isomers of the hydroxyquinoline molecular ion, and [M-CS] +. ions from various positional isomers of the mercaptoquinoline molecular ion. CID/MIKES spectra give evidence in favour of the [M-CO] +. and [M-CS] +. ions from the 2-, 3- and 4-isomers adopting an indole-like structure. Deuterium labelling experiments with the [M- CO] +. and [M-CS] +. ions showed the uniqueness of the two 2-isomers, which unlike the other positional isomers, gave no evidence of hydrogen scrambling. It has already been shown through the study of the metastable peak corresponding to the loss of CO from the molecular ion that 2-hydroxyquinioline is tautomeric with quinolin- (1H)-one. This type of study was extended to structurally related ions that also lost CO, revealing other instances of tautomerism and competitive routes for loss of CO from a single ion. A comparative study using various MS/MS techniques was carried out on the acetamide ion, comparing its structure with C2H5NO+. ions formed from N-ethylacetamide and n-butyramide by a McLafferty rearrangement. A similar study was made of t-butylbenzene, various techniques being used to investigate its fragmentation pattern and the structure of the ions formed. It has been reported that the analysis of mass spectral data from peptides is greatly aided by close examination of low mass peaks, particularly those due to immonium ions and other closely associated ions. Tandem mass spectrometry was used to study the effects of small changes in the peptide sequence on the relative abundances of these low mass ions

Supporting student e-portfolios

Historically, the term portfolio has been used to describe a folder of work used predominantly for skill recording and display purposes. It was mainly paper based, usually begun when its author was a student and developed over a working lifetime. More recently the term has been taken up for use in schools and colleges, describing a more modest folder holding work from a particular project or an entire course, and in professional fields as a collection of material required to evidence competence for accreditation or to prepare for assessment. Since its inception as an evolution of this traditional portfolio, the electronic portfolio or e-portfolio has attracted a great deal of interest from around the world where there is readyaccess to suitable technology. This interest continues to grow with increasing numbers of students and professionals being encouraged, or required, to produce e-portfolios.This article focuses on e-portfolios in the higher education (HE) sector, principally those authored by students. Its purpose is to provide a basic introduction to e-portfolios: what they are, how they are being used, potential benefits and challenges, and guidance for their successful introduction

Editorial

Editorial by Tracey Madde

Editorial

New Directions focuses on new developments by practitioners in the field of learning and teaching.There is a strong outreach theme in this issue with articles covering activities in chemistry and physics, and the effects on all parties involved. Assessment and feedback also feature heavily, with articles on screencasting, delivering audio feedback and designing multiple choice questions (MCQs.) Ever popular topics including undergraduate practical work, transition to university and mathematics support for chemists appear, along with articles on prior knowledge of undergraduates, use of learning outcomes and educational research projects for students.This is the last issue of New Direction that the Centre will produce; we now hand the baton to the Higher Education Academy www.heacademy.ac.uk to produce future issues. We would like to take this opportunity to thank all our contributors and reviewers who have made this publication possible, and we hope that you the reader have found value in what we have offered

Editorial

Editorial by Tracey Madden

Tutors and gatekeepers in sustainability MOOCS

Purpose The purpose of this paper is to explore the nature of interactions between learners in a massive open online course (MOOC), particularly role of the tutors in such interactions. For educators concerned with sustainability literacy, the authors are necessarily both affected by, and effectors of, digital pedagogies. The call for papers for this special issue challenged the authors to consider whether digital pedagogies are “supportive of sustainability or perpetuators of unsustainability”. As might be expected, this question is not a simple binary choice and the authors have chosen to address it indirectly, by considering the nature of interaction in a global, digitally connected community of learners. In particular, the changing role of tutors in these communities, and the possible implications of this change on sustainable literacy, are examined. Design/methodology/approach The authors focus on the “Sustainability for Professionals” massive open online course (MOOC) delivered by the University of Bath on the FutureLearn platform which hosts the “Inside Cancer” MOOC, also from Bath. “Sustainability for Professionals” is pedagogically connectivist, with “Inside Cancer” being more traditional and instructor led. The authors used social network analysis (SNA) for the research. It is a key tool to understand interactions in an online environment and allows quantitative comparison between different networks and thus between courses. In the context of digital pedagogy, the authors used a number of relevant SNA metrics to carry out analysis of MOOC network structures. Findings It was found that MOOCs are different in their network structure but tend to adapt to the subject matter. Digital pedagogies for sustainability result in a qualitative as well as quantitative change in learning where course design affects the learning process and gatekeepers are critical for information flow. These gatekeepers are distinct from tutors in the network. In such a network, tutors’ role is limited to course delivery and verifying, depending on course content, the information within the network. The analysis shows that network learning is dependent on course design and content, and gatekeepers exercise influence over the information within the network. Originality/value This study has implications for sustainability literacy. The authors examined the extent to which patterns of interaction in the network affect the learning process, and how this can help participants engage with the concept of sustainability. They used SNA to explore the nature of interaction between learners in a MOOC, particularly the role of the tutors in mediating such interactions. They also found that tutors can and do take a central role in early runs of the MOOC; however, with the subsequent runs, the removal of tutor nodes has little effect, suggesting that different modes of learning driven by participants are possible in a MOOC community. </jats:sec

Processing of a Multiple Membrane Spanning Epstein-Barr Virus Protein for Cd8+T Cell Recognition Reveals a Proteasome-Dependent, Transporter Associated with Antigen Processing–Independent Pathway

Epstein-Barr virus (EBV) latent membrane protein (LMP)2 is a multiple membrane spanning molecule which lacks ectodomains projecting into the lumen of the endoplasmic reticulum (ER). Human CD8+ cytotoxic T lymphocytes (CTL)s recognize a number of epitopes within LMP2. Assays with epitope-specific CTLs in two different cell backgrounds lacking the transporter associated with antigen processing (TAP) consistently show that some, but not all, LMP2 epitopes are presented in a TAP-independent manner. However, unlike published examples of TAP-independent processing from endogenously expressed antigens, presentation of TAP-independent LMP2 epitopes was abrogated by inhibition of proteasomal activity. We found a clear correlation between hydrophobicity of the LMP2 epitope sequence and TAP independence, and experiments with vaccinia minigene constructs expressing cytosolic epitope peptides confirmed that these more hydrophobic peptides were selectively able to access the HLA class I pathway in TAP-negative cells. Furthermore, the TAP-independent phenotype of particular epitope sequences did not require membrane location of the source antigen since (i) TAP-independent LMP2 epitopes inserted into an EBV nuclear antigen and (ii) hydrophobic epitope sequences native to EBV nuclear antigens were both presented in TAP-negative cells. We infer that there is a proteasome-dependent, TAP-independent pathway of antigen presentation which hydrophobic epitopes can selectively access

Shared genetic risk between eating disorder- and substance-use-related phenotypes:Evidence from genome-wide association studies

First published: 16 February 202