A model of hyphal tip growth involving microtubule-based transport

We propose a simple model for mass transport within a fungal hypha and its subsequent growth. Inspired by the role of microtubule-transported vesicles, we embody the internal dynamics of mass inside a hypha with mutually excluding particles progressing stochastically along a growing one-dimensional lattice. The connection between long range transport of materials for growth, and the resulting extension of the hyphal tip has not previously been addressed in the modelling literature. We derive and analyse mean-field equations for the model and present a phase diagram of its steady state behaviour, which we compare to simulations. We discuss our results in the context of the filamentous fungus, Neurospora crassa.Comment: 5 pages, 5 figure

Disclosing an autism diagnosis improves ratings of candidate performance in employment interviews

Employment interviews can be challenging for autistic people. In addition to standard interview procedures often being inaccessible, features associated with autism (including atypical emotional expression, eye-contact, and gestures) may lead to negative first impressions. Research using vignettes and ‘thin slices’ of communication indicate that perceptions of an autistic individual can be improved when their autism diagnosis is disclosed. Here, we examined the impact of diagnostic disclosure on judgements of autistic adults undergoing an entire mock employment interview. A total of 119 participants (known as ‘raters’) watched a video of an autistic candidate’s mock employment interview, after which they provided overall impressions of the candidate on factors such as confidence, motivation, and knowledgeability. Raters were either (1) unaware of the interviewee’s diagnosis, (2) aware of their diagnosis, or (3) aware of their diagnosis and provided with information about autism. Results indicate that diagnostic disclosure improved perceptions of autistic candidates across all dimensions compared to when raters were unaware of their diagnosis. The provision of additional information about the diagnosis did not further improve ratings. The findings have important implications for employers and autistic people, who should consider the potential impact of diagnostic disclosure prior to interviewing for a role

Auto-driven Photo Elicitation Interviews in Research with Children: Ethical and Practical Considerations

Children can sometimes find it difficult to articulate their experiences if they have to rely solely on words. Giving children the opportunity to use arts-based research approaches can support their participation in research and create a bridge that enables them to express their perspectives and feelings. This paper focuses on the ethical and practical considerations when using photo elicitation interviews (PEI) in research with children. The discussion and examples provided are drawn from an international study that used auto-driven PEI, where photographs are taken by children themselves, to explore children’s experiences of living with a chronic condition and the impact condition management may have on their everyday lives. In this paper we critically explore the issues arising from our use of PEI including children’s participation and engagement, balancing power and control, and keeping children safe. The main areas of focus for the paper are how PEI provided a means of shifting control; how setting photographic boundaries influenced our PEI study with children; and how we addressed risks associated with the method. Our experience shows that PEI is an engaging and valuable research method, providing a powerful medium for obtaining rich data with children. However, PEI is challenging and it requires researchers to conscientiously address ethical and practical aspects that extend beyond those inherent to standard (words-alone) interviews

Teacher and Student-focused Approaches: influence of learning approach and self-efficacy in a psychology postgraduate sample

The current study examined approaches to teaching in a postgraduate psychology sample. This included considering teaching-focused (information transfer) and student-focused (conceptual changes in understanding) approaches to teaching. Postgraduate teachers of psychology ( N = 113) completed a questionnaire measuring their use of a teacher- or student-focused approach, deep and surface approaches to learning and teaching, and research self-efficacy. Standard multiple regressions revealed that the manner in which postgraduate students approached their own studies (i.e., deep or surface learning approach) predicted the use of a teacher- or student-focused approach in their teaching practice. Specifically, postgraduates adopting a deep approach to their own learning were more likely to adopt a teaching-focused approach to their teaching practice. Those adopting a surface approach to their own studies were most likely to adopt a student-focused approach. Furthermore, postgraduates with a high level of teaching self-efficacy were more likely to adopt a student-focused approach to teaching practice. Additionally, postgraduates who had received formal teaching training scored higher on teacher self-efficacy than those who had not received such training. Taken together, the findings suggest the key role of formal training in enhancing self-efficacy in teaching, and demonstrate an association between the learning styles adopted by postgraduate teachers and their approach to teaching. </jats:p

Electronic Structure Description of a Doubly Oxidized Bimetallic Cobalt Complex with Pro-Radical Ligands

The geometric and electronic structure of a doubly oxidized bimetallic Co complex containing two redox-active salen moieties connected via a 1,2-phenylene linker has been investigated and compared to an oxidized monomeric analogue. Both complexes, CoL1 and Co2L2 are oxidized to the mono- and di-cations respectively with AgSbF6 and characterized by X-ray crystallography for the monomer, and Vis-NIR spectroscopy, electron paramagnetic (EPR) spectroscopy, SQUID magnetometry and density functional theory (DFT) calculations for both the monomer and dimer. Both complexes exhibit a water molecule coordinated in the apical position upon oxidation. [CoL1-H2O]+ displays a broad NIR band at 8500 cm-1 (8400 M-1cm-1) which is consistent with recent reports on oxidized Co salen complexes (Kochem, A. et. al., Inorg Chem., 2012, 51, 10557-10571, Kurahashi, T. et. al., Inorg. Chem., 2013, 52, 3908-3919). DFT calculations predict a triplet ground state with significant ligand and metal contributions to the singularly occupied molecular orbital (SOMO). The majority (~75%) of the total spin density is localized on the metal, highlighting both high spin Co(III) and Co(II)L• character in the electronic ground state. Further oxidation of CoL1 to the dication affords a low spin Co(III) phenoxyl radical species. The NIR features for [Co2L2-2H2O]2+ at 8600 cm-1 (17800 M-1cm-1) are doubly intense in comparison to [CoL1-H2O]+ owing to the description of [Co2L2-2H2O]2+ as two non-interacting oxidized Co salen complexes bound via the central phenylene linker. Interestingly, TD-DFT calculations predict two electronic transitions that are 353 cm-1 apart. The NIR spectrum of the analogous Ni complex, [Ni2L2]2+, exhibits two intense transitions (4890 cm-1/26500 M-1cm-1 and 4200 cm-1/21200 M-1cm-1) due to exciton coupling in the excited state. Only one broad band is observed in the NIR spectrum for [Co2L2-2H2O]2+ as a result of the contracted donor and acceptor orbitals and overall CT character

Mechanistic insights into allosteric regulation of the A2A adenosine G protein-coupled receptor by physiological cations.

Cations play key roles in regulating G-protein-coupled receptors (GPCRs), although their mechanisms are poorly understood. Here, 19F NMR is used to delineate the effects of cations on functional states of the adenosine A2A GPCR. While Na+ reinforces an inactive ensemble and a partial-agonist stabilized state, Ca2+ and Mg2+ shift the equilibrium toward active states. Positive allosteric effects of divalent cations are more pronounced with agonist and a G-protein-derived peptide. In cell membranes, divalent cations enhance both the affinity and fraction of the high affinity agonist-bound state. Molecular dynamics simulations suggest high concentrations of divalent cations bridge specific extracellular acidic residues, bringing TM5 and TM6 together at the extracellular surface and allosterically driving open the G-protein-binding cleft as shown by rigidity-transmission allostery theory. An understanding of cation allostery should enable the design of allosteric agents and enhance our understanding of GPCR regulation in the cellular milieu

Academic achievement : the role of praise in motivating students

The motivation of students is an important issue in higher education, particularly in the context of the increasing diversity of student populations. A social-cognitive perspective assumes motivation to be dynamic, context-sensitive and changeable, thereby rendering it to be a much more differentiated construct than previously understood. This complexity may be perplexing to tutors who are keen to develop applications to improve academic achievement. One application that is within the control of the tutor, at least to some extent, is the use of praise. Using psychological literature the article argues that in motivating students, the tutor is not well served by relying on simplistic and common sense understandings of the construct of praise and that effective applications of praise are mediated by students' goal orientations, which of themselves may be either additive or interactive composites of different objectives and different contexts

Rotation periods of late-type stars in the young open cluster IC 2602

We present the results of a monitoring campaign aimed at deriving rotation periods for a representative sample of stars in the young (30 Myr) open cluster IC 2602. Rotation periods were derived for 29 of 33 stars monitored. The periods derived range from 0.2d (one of the shortest known rotation periods of any single open cluster star) to about 10d (which is almost twice as long as the longest period previously known for a cluster of this age). We are able to confirm 8 previously known periods and derive 21 new ones, delineating the long period end of the distribution. Despite our sensitivity to longer periods, we do not detect any variables with periods longer than about 10d. The combination of these data with those for IC 2391, an almost identical cluster, leads to the following conclusions: 1) The fast rotators in a 30 Myr cluster are distributed across the entire 0.5 < B-V < 1.6 color range. 2) 6 stars in our sample are slow rotators, with periods longer than 6d. 3) The amplitude of variability depends on both the color and the period. The dependence on the latter might be important in understanding the selection effects in the currently available rotation period database and in planning future observations. 4) The interpretation of these data in terms of theoretical models of rotating stars suggests both that disk-interaction is the norm rather than the exception in young stars and that disk-locking times range from zero to a few Myr.Comment: 23 pages, 8 figures, accepted for publication in the Astrophysical Journa

E-learning as a tool for knowledge transfer through traditional and independent study at two UK higher educational institutes: a case study

Much has been made of the advances in computer aided learning activities. Websites, virtual campus, the increased use of Web CT and chat rooms and further advances in the use of WebCT are becoming more commonplace in UK universities. This paper looks for ways of changing higher education students’ perception of the usefulness of recommended internet web sites for learning purposes, with the intention of increasing the usage rate of recommended module web-sites. The change could represent an adaptation of the existing, well-known technology to change students’ perception regarding its potentially formative role. Subsequently, the outcomes from this preliminary research could be used in order to enhance the quality of the Internet use for teaching and learning purposes