Organization of the musculature of schistosome cercariae

Phalloidin-fluorescein isothiocyanate staining of filamentous actin was used to identify muscle systems within the cercariae of Schistosoma mansoni. Examination of labeled cercariae by confocal scanning laser microscopy revealed distinct organizational levels of myofiber arrangements within the body wall, anterior cone, acetabulum, and esophagus. The body wall throughout showed a typical latticelike arrangement of outer circular and inner longitudinal myofibers, with an additional innermost layer of diagonal fibers in the anterior portion of the body. Circular and longitudinal fibers were also evident in the anterior organ and esophagus and. to some extent, the ventral acetabulum. Most striking was the striation of the cercarial tail musculature.

Modelling Vibrated Stone Colums in Soft Clay

The vibrated stone column technique is an economical and environmentally friendly process that treats weak ground to enable it to withstand low to moderate loading conditions. The performance of the treated ground depends on various parameters such as the strengths of the in-situ and backfill materials, and the spacing, length and diameter of the columns. In practice, vibrated stone columns are frequently used for settlement control. Studies have shown that columns can fail by bulging, bending, punching or shearing. These failure mechanisms are examined in this paper. The study involved a series of laboratory model tests on a consolidated clay bed. The tests were carried out using two different materials: (a) transparent material with ‘clay like’ properties, and (b) speswhite kaolin. The tests on the transparent material have, probably for the first time, permitted visual examination of deforming granular columns during loading. They have shown that bulging was significant in long columns, whereas punching was prominent in shorter columns. The presence of the columns also greatly improved the load-carrying capacity of the soft clay bed. However, columns longer than about six times their diameter did not lead to further increases in the load-carrying capacity. This suggests that there is an optimum column length for a given arrangement of stone columns beneath a rigid footing.

On the structure and dynamics of ionic liquids

The structure and dynamics of the ionic liquid 1-ethyl-3-methylimidazolium nitrate is studied by molecular dynamics simulations. We find long-range spatial correlations between the ions and a three-dimensional local structure that reflects the asymmetry of the cations. The main contribution to the configurational energy comes from the electrostatic interactions which leads to charge-ordering effects. Radial screening and threedimensional distribution of charge are also analyzed. The motion of a single ion is studied via velocity and reorientational correlation functions. It is found that ions "rattle" in a long-lived cage, while the orientational structure relaxes on a time scale longer than 200 ps. As in a supercooled liquid, the mean square displacements reveal a subdiffusive dynamics. In addition, the presence of dynamic heterogeneities can be detected by analyzing the non-Gaussian behavior of the van Hove correlation function and the spatial arrangement of the most mobile ions. The short-time collective dynamics is also studied through the electric current time correlation function.

Towards Improving the Utilisation of University Teaching Space

There is a perception that teaching space in universities is a rather scarce resource. However, some studies have revealed that in many institutions it is actually chronically under-used. Often, rooms are occupied only half the time, and even when in use they are often only half full. This is usually measured by the ‘utilization’ which is defined as the percentage of available ‘seat-hours’ that are employed. Within real institutions, studies have shown that this utilization can often take values as low as 20–40%. One consequence of such a low level of utilization is that space managers are under pressure to make more efficient use of the available teaching space. However, better management is hampered because there does not appear to be a good understanding within space management (near-term planning) of why this happens. This is accompanied, within space planning (long-term planning) by a lack of experise on how best to accommodate the expected low utilizations. This motivates our two main goals: (i) To understand the factors that drive down utilizations, (ii) To set up methods to provide better space planning. Here, we provide quantitative evidence that constraints arising from timetabling and location requirements easily have the potential to explain the low utilizations seen in reality. Furthermore, on considering the decision question ‘Can this given set of courses all be allocated in the available teaching space?’ we find that the answer depends on the associated utilization in a way that exhibits threshold behaviour: There is a sharp division between regions in which the answer is ‘almost always yes’ and those of ‘almost always no’. Through analysis and understanding of the space of potential solutions, our work suggests that better use of space within universities will come about through an understanding of the effects of timetabling constraints and when it is statistically likely that it will be possible for a set of courses to be allocated to a particular space. The results presented here provide a firm foundation for university managers to take decisions on how space should be managed and planned for more effectively. Our multi-criteria approach and new methodology together provide new insight into the interaction between the course timetabling problem and the crucial issue of space planning.

The musculature and associated innervation of adult and intramolluscan stages of Echinostoma caproni (Trematoda) visualised by confocal microscopy

Gross anatomy of muscle and sensory/motor innervation of adult and intramolluscan developmental stages of Echinostoma caproni have been investigated to ascertain the organisation and the functional correlates of any stage-specific patterns of staining. Using indirect immunocytochemistry to demonstrate neuroactive substances and the phalloidin-fluorescence technique for staining myofibril F-actin, the muscle systems and aminergic and peptidergic innervation of daughter rediae, cercariae, metacercariae, and pre- and post-ovigerous adults were examined and compared using confocal scanning laser microscopy. A complex arrangement of specific muscle fibre systems occurs within the body wall (composed of circular, longitudinal and diagonal fibres), suckers (radial, equatorial, meridional), pharynx (radial, circular), gut caeca (mainly circular), cercarial tail (circular, pseudo-striated longitudinal), and ducts of the reproductive system (circular, longitudinal), presumed to serve locomotor, adhesive, alimentary and reproductive functions. Immunostaining for serotonin (5-HT) and FMRFamide-related peptides (FaRPs) was evident throughout the central (CNS) and peripheral (PNS) nervous systems of all stages, and use of dual-labelling techniques demonstrated separate neuronal pathways for 5-HT and FaRP in both CNS and PNS. FaRP expression in the innervation of the ootype wall was demonstrated only in post-ovigerous worms and not in pre-ovigerous worms, suggesting an involvement of FaRP neuropeptides in the process of egg assembly. Comparison of the present findings with those recorded for other digeneans suggests that muscle organisation and innervation patterns in trematodes are highly conserved.

Improving the utilisation of University teaching space

There is a perception that teaching space in universities is a rather scarce resource. However, some studies have revealed that in many institutions it is actually chronically under-used. Often, rooms are occupied only half the time, and even when in use they are often only half full. This is usually measured by the “utilisation” which is basically the percentage of available ’seat-hours’ that are employed. In real institutions, this utilisation can often takes values as low as 20-40%. One consequence of such low utilisation is that space managers are under pressure to make a more efficient use of the available teaching space. However, better management is hampered because there does not appear to be a good understanding within space management (near-term planning) of why this happens. Nor, a good basis within space planning (long-term planning) of how best to accommodate the expected low utilisations. This motivates our two main goals: (i) To understand the factors that drive down utilisations, (ii) To set up methods to provide better space planning. Here, we provide quantitative evidence that constraints arising from timetabling and location requirements easily have the potential to explain the low utilisations seen in reality. Furthermore, on considering the decision question “Can this given set of courses all be allocated in the available teaching space?” we find that the answer depends on the associated utilisation in a way that exhibits threshold behaviour: There is a sharp division between regions in which the answer is “almost always yes” and those of “almost always no”. Our work suggests that progress in space management and planning will arise from an integrated approach; combining purely space issues with restrictions representing an aggregated or abstracted version of key constraints such as timetabling or location, and

Morphological Expression of KIT Positive Interstitial Cells of Cajal in Human Bladder

PURPOSE: We investigated the 3-dimensional morphological arrangement of KIT positive interstitial cells of Cajal in the human bladder and explored their structural interactions with neighboring cells.MATERIALS AND METHODS: Human bladder biopsy samples were prepared for immunohistochemistry/confocal or transmission electron microscopy.RESULTS: Whole mount, flat sheet preparations labeled with anti-KIT (Merck, Darmstadt, Germany) contained several immunopositive interstitial cell of Cajal populations. A network of stellate interstitial cells of Cajal in the lamina propria made structural connections with a cholinergic nerve plexus. Vimentin positive cells of several morphologies were present in the lamina propria, presumably including fibroblasts, interstitial cells of Cajal and other cells of mesenchymal origin. Microvessels were abundant in this region and branched, elongated KIT positive interstitial cells of Cajal were found discretely along the vessel axis with each perivascular interstitial cell of Cajal associated with at least 6 vascular smooth muscle cells. Detrusor interstitial cells of Cajal were spindle-shaped, branched cells tracking the smooth muscle bundles, closely associated with smooth muscle cells and vesicular acetylcholine transferase nerves. Rounded, nonbranched KIT positive cells were more numerous in the lamina propria than in the detrusor and were immunopositive for anti-mast cell tryptase. Transmission electron microscopy revealed cells with the ultrastructural characteristics of interstitial cells of Cajal throughout the human bladder wall.CONCLUSIONS: The human bladder contains a network of KIT positive interstitial cells of Cajal in the lamina propria, which make frequent connections with a cholinergic nerve plexus. Novel perivascular interstitial cells of Cajal were discovered close to vascular smooth muscle cells, suggesting interstitial cells of Cajal-vascular coupling in the bladder. KIT positive detrusor interstitial cells of Cajal tracked smooth muscle bundles and were associated with nerves, perhaps showing a functional tri-unit controlling bladder contractility.

Identification of a major GpVI-binding locus in human type III collagen

We have analyzed the adhesion of human and murine platelets, and of recombinant human and murine GpVI ectodomains, to synthetic triple-helical collagen-like peptides. These included 57 peptides derived from the sequence of human type III collagen and 9 peptides derived from the cyanogen bromide fragment of bovine type III collagen, alpha 1(III)CB4. We have identified several peptides that interact with GpVI, in particular a peptide designated III-30 with the sequence GAOGLRGGAGPOG-PEGGKGAAGPOGPO. Both human and murine platelets bound to peptide III-30 in a GpVI-dependent manner. III-30 also supported binding of recombinant GpVI ectodomains. Cross-linked III-30 induced aggregation of human and murine platelets, although with a lower potency than collagen-related peptide. Modifications of the peptide sequence indicated that the hydroxyproline residues play a significant role in supporting its GpVI reactivity. However, many peptides containing OGP/ GPO motifs did not support adhesion to GpVI. These data indicate that the ability of a triple-helical peptide to bind GpVI is not solely determined by the presence or spatial arrangement of these OGP/GPO motifs within the peptides.

The level playing field: the impact of assessment practice on professional development

Context: The effects of assessment practice on students’ learning are unclear, particularly regarding professional development. Corralling in objective structured clinical examinations (OSCEs) is designed to reduce illicit passing of examination information. Candidates completing an examination are kept secluded until the next cohort of examinees has begun. We used the introduction of corralling as a context in which to explore social influences on examination misconduct, with the aims of improving understanding of the hidden effects of assessment, and evaluating the acceptability of corralling from the student perspective.

Methods: A questionnaire was administered to students corralled post-OSCE for the first time. Eleven semi-structured interviews were subsequently conducted. Questionnaire data were analysed for descriptive statistics and thematic analysis of interview transcripts was carried out.

Results: The questionnaire response rate was 95.4% (251/263). Before corralling, 80.9% (203/251) of students were aware of the sharing of information among peers and 78.5% (197/251) agreed that such misconduct was unprofessional. The majority were in favour of corralling (90.8%, 228/251). Four themes emerged from the semi-structured interviews: the student network versus the individual; assessment-driven culture; the deferring of professionalism, and the ‘level playing field’. Students saw interaction within the student network, on a background of assessment-driven culture, as the key driver in examination misconduct. Conforming to the rules of the social network was prioritised over individual agency, although the mismatch between the rules of the network and the dominant professional discourse caused some conflict for individuals. Deferred professionalism (described as the practice of taking on the norms of professional behaviour only when qualified) was a rationalisation used to minimise this conflict. Corralling provided a ‘level playing field’ in which the influences of the network were minimised.

Conclusions: Examination misconduct is thus a complex social construction with implications for individual learners in terms of professional development. Corralling is one mechanism for addressing misconduct that is acceptable to students, but assessment processes have important hidden effects which educators should acknowledge.

Gross anatomy of the muscle systems of Fasciola hepatica as visualized by phalloidin-fluorescence and confocal microscopy

Neuropeptides, biogenic amines and acetylcholine are expressed abundantly within the nervous systems of parasitic flatworms, and are particularly evident in the innervation of the musculature. Such associations have implicated the nervous system in locomotion, host attachment and reproductive co-ordination. Information on the muscle systems of parasitic flatworms is generally sparse, in particular those muscles associated with the reproductive system, intestinal tract and attachment apparatus. Also, the use of sectioned material has left description of the 3-dimensional organization of the musculature largely unrecorded. Using fluorescein isothiocyanate (FITC)-labelled phalloidin as a site-specific probe for filamentous actin, applied to whole-mount preparations of adult Fasciola hepatica and examined by confocal scanning laser microscopy, the present work reports on the organization of the major muscle systems in this trematode parasite. A highly regular array of outer circular, intermediate longitudinal and inner diagonal fibres distinguishes the body wall musculature, which is also involved in the development of both ventral and oral suckers. Circular fibres dominate the duct walls of the male and female reproductive systems, whereas the muscles of the intestinal tract have a somewhat diffuse arrangement of fibres. An understanding of the structural complexity of the muscle systems of parasitic flatworms is considered as fundamental to the interpretation of results from physiological experiments.

Adsorption and aggregation properties of norovirus GI and GII virus-like particles demonstrate differing responses to solution chemistry

The transport properties (adsorption and aggregation behavior) of virus-like particles (VLPs) of two strains of norovirus ("Norwalk" GI.1 and "Houston" GII.4) were studied in a variety of solution chemistries. GI.1 and GII.4 VLPs were found to be stable against aggregation at pH 4.0-8.0. At pH 9.0, GI.1 VLPs rapidly disintegrated. The attachment efficiencies (a) of GI.1 and GII.4 VLPs to silica increased with increasing ionic strength in NaCl solutions at pH 8.0. The attachment efficiency of GI.1 VLPs decreased as pH was increased above the isoelectric point (pH 5.0), whereas at and below the isoelectric point, the attachment efficiency was erratic. Ca(2+) and Mg(2+) dramatically increased the attachment efficiencies of GI.1 and GII.4 VLPs, which may be due to specific interactions with the VLP capsids. Bicarbonate decreased attachment efficiencies for both GI.1 and GII.4 VLPs, whereas phosphate decreased the attachment efficiency of GI.1, while increasing GII.4 attachment efficiency. The observed differences in GI.1 and GII.4 VLP attachment efficiencies in response to solution chemistry may be attributed to differential responses of the unique arrangement of exposed amino acid residues on the capsid surface of each VLP strain.

Creating a Circus of Words, Music, and Sound: From Roaratorio to Owenvarragh

This article documents the creation of a work by the authors based on a score written by the composer John Cage entitled 'Owenvarragh: A Belfast Circus on The Star Factory.' The article is part of a documentary portfolio in the journal which also includes a volume of the poetry created by Dowling in accordance with the instructions of the Cage score, and a series of documentary videos on the creation of the work and its first performance. Cage's score is based on his work 'Roaratorio: An Irish Circus on Finnegan's Wake' (1979) and it provides a set of detailed instructions for the musical realisation of a literary work. The article documents this first fully realised version of the score since Cage first produced 'Roaratorio' in 1979. The work, which was motivated by the Cage centenary year in 2012, musically realises Carson's book 'The Star Factory' (1998), a novelestic autobiography of Carson's Belfast childhood. The score required the creation of a fixed media piece based on over 300 field recordings of the sounds and places mentioned in the book, a volume of poetry created from the book which is recited to form the rhythmic spine of the work, and the arrangement of a performance including these two components along with live musical performance by the authors in collaboration with three other musicians under their direction, and a video installation created for the work. The piece has been performed three times: in association with the Sonorities 2012 Festival at Queen's University of Belfast (March 2012), at The Belfast Festival at Queen's (October 2012), and in the Rymer Auditoium of the University of York (June 2013).

Additional information:

The work which the article documents was conceived by Monaghan and Dowling, and the project was initiated by Monaghan after a she received a student prize to support its development and first performance. Elements of the project will be included in her PhD dissertation for which Dowling is a supervisor. Monaghan created the fixed media piece based on over 300 field recordings, the largest single aspect of realising Cage's score. Dowling was responsible for initiating the collaboration with Ciaran Carson, and for two other components: the creation of a volume of poetry derived from the literary work which is recited in the performance, and the creation of and supervision of the technical work on a video which accompanies the piece. The co-authors consulted closely during the work on these large components from May 2011 until March 2012 when the first performance took place. The co-authors also shared in numerous other artistic and organisational aspects of the production, including the arrangement and performnance of the music, musical direction to other performers, and marketing.

Cloning and characterisation of three novel disintegrin precursors from the venoms of three Atheris species: Atheris chlorechis, Atheris nitschei and Atheris squamigera

Snake venom constitutes one of the most complex mixtures of naturally-occurring toxic proteins/polypeptides and a large number of these possess very profound biological activities. Disintegrins, that are commonly found in viper venoms, are low molecular weight proteins that usually contain an -Arg-Gly-Asp- (-RGD-) motif that is known to be involved in cell adhesion ligand recognition, binding specifically to cell surface integrin receptors and also exhibiting platelet anti-aggregation activity.

Here, we report for the first time, the successful cloning of three cDNAs encoding disintegrin precursors from lyophilised venom-derived libraries of Atheris chlorechis, Atheris nitschei and Atheris squamigera, respectively. All of these disintegrins belong to the short-coding class and all exhibit high degrees of structural identity, both in their amino acid sequences and in the arrangement of their functional domains. Mass spectrometric analyses of the HPLC-separated/in-gel digested venom proteins was performed to characterise the mature disintegrins as expressed in the venom proteome. Studies on both the structures and conserved sites within these disintegrins are of considerable theoretical interest in the field of biological evolution and in the development of new research tools or novel templates for drug design.

Structural and electronic properties of Ce overlayers and low-dimensional Pt-Ce alloys on Pt{111}

The structural, thermal, chemisorptive, and electronic properties of Ce on Pt{111} are studied by photoemission, Auger spectroscopy, scanning tunnel microscope (STM), and low-energy electron diffraction (LEED). Stranski-Krastanov-like growth of low-density Ce layers is accompanied by substantial valence charge transfer from Ce to Pt: in line with this, the measured dipole moment and polarizability of adsorbed Ce at low coverages are 7.2 x 10(-30) C m and similar to 1.3x10(-29) m(3), respectively. Pt-Ce intermixing commences at similar to 400 K and with increasing temperature a sequence of five different ordered surface alloys evolves. The symmetry, periodicities, and rotational epitaxy observed by LEED are in good accord with the STM data which reveal the true complexity of the system. The Various bimetallic surface phases are based on growth of crystalline Pt5Ce, a hexagonal layer structure consisting of alternating layers of Pt2Ce and Kagome nets of Pt atoms. This characteristic ABAB layered arrangement of the surface alloys is clearly imaged, and chemisorption data permit a distinction to be made between the more reactive Pt2Ce layer and the less reactive Pt Kagome net. Either type of layer can appear at the surface as the terminating structure, thicker films exhibiting unit mesh parameters characteristic of the bulk alloy.