FASCIOLA-HEPATICA - LOCALIZATION AND PARTIAL CHARACTERIZATION OF TUBULIN

The localisation and distribution of the cytoskeletal protein tubulin in the adult liver fluke Fasciola hepatica have been determined by an indirect immunofluorescence technique using a monoclonal antibody raised against beta-tubulin. Tubulin was demonstrated in the tegumental syncytium and in the tegumental cell bodies and their cytoplasmic connections with the surface syncytium. Immunostaining was also evident in the nerve fibres innervating sensory receptors in the tegument, in the nerve plexus innervating the sub-tegumental musculature and in the cytoplasmic extensions of the nurse cells within the vitelline follicle. Immunoblotting of whole fluke fractions produced a single band corresponding to a molecule of approximately 54 kDa in size. This figure corresponds with previous data obtained on tubulin from other helminth and eukaryotic sources.

ISOLATION AND PARTIAL SEQUENCING OF A PANCREATIC POLYPEPTIDE-LIKE NEUROPEPTIDE FROM THE LIVER FLUKE, FASCIOLA-HEPATICA

1. A pancreatic polypeptide (PP)-immunoreactive neuropeptide has been isolated and partially sequenced from the liver fluke, Fasciola hepatica.

Pharmacy Students’ Views of Faculty Feedback on Academic Performance

Objective: To investigate students' views on and satisfaction with faculty feedback on their academic performance.

Methods: A 41-item survey instrument was developed based on a literature review relating to effective feedback. All pharmacy undergraduate students were invited via e-mail to complete the self-administered electronic questionnaire relating to their views on feedback, including faculty feedback received to date regarding their academic performance.

Results: A response rate of 61% (343/561) was obtained. Only 32.3% of students (107/331) agreed that they were satisfied with the feedback they received; dissatisfaction with examination feedback was particularly high. The provision of faculty feedback was perceived to be variable in terms of quality and quantity.

Conclusions: There are some inconsistencies relating to provision of feedback within the MPharm degree program at Queen's University Belfast. Further work is needed to close the gap between student expectations and the faculty's delivery of feedback on academic performance.

Partial and total multiphoton detachment rates for H- in a perturbative B-spline-based approach

An ab initio approach has been applied to study multiphoton detachment rates for the negative hydrogen ion in the lowest nonvanishing order of perturbation theory. The approach is based on the use of B splines allowing an accurate treatment of the electronic repulsion. Total detachment rates have been determined for two- to six-photon processes as well as partial rates for detachment into the different final symmetries. It is shown that B-spline expansions can yield accurate continuum and bound-state wave functions in a very simple manner. The calculated total rates for two- and three-photon detachment are in good agreement with other perturbative calculations. For more than three-photon detachment little information has been available before now. While the total cross sections show little structure, a fair amount of structure is predicted in the partial cross sections. In the two-photon process, it is shown that the detached electrons mainly have s character. For four- and six-photon processes, the contribution from the d channel is the most important. For three- and five-photon processes p electrons dominate the electron emission spectrum. Detachment rates for s and p electrons show minima as a function of photon energy. © 1994 The American Physical Society.

The agonism and synergistic potentiation of weak partial agonists by triethylamine in alpha(1)-adrenergic receptor activation: Evidence for a salt bridge as the initiating process

alpha(1)-adrenergic receptor (AR) activation is thought to be initiated by disruption of a constraining interhelical salt bridge (Porter et al., 1996). Disruption of this salt bridge is achieved through a competition for the aspartic acid residue in transmembrane domain three by the protonated amine of the endogenous ligand norepinephrine and a lysine residue in transmembrane domain seven. To further test this hypothesis, we investigated the possibility that a simple amine could mimic an important functional group of the endogenous ligand and break this alpha(1)-AR ionic constraint leading to agonism. Triethylamine (TEA) was able to generate concentration-dependent increases of soluble inositol phosphates in COS-1 cells transiently transfected with the hamster alpha(1b)-AR and in Rat-1 fibroblasts stably transfected with the human alpha(1a)-AR subtype. TEA was also able to synergistically potentiate the second messenger production by weak partial alpha(1)-AR agonists and this effect was fully inhibited by the alpha(1)-AR antagonist prazosin. However, this synergistic potentiation was not observed for full alpha(1)-AR agonists. Instead, TEA caused a parallel rightward shift of the dose-response curve, consistent with the properties of competitive antagonism. TEA specifically bound to a single population of alpha(1)-ARs with a K-i of 28.7 +/- 4.7 mM. In addition, the site of binding by TEA to the alpha(1)-AR is at the conserved aspartic acid residue in transmembrane domain three, which is part of the constraining salt bridge. These results indicate a direct interaction of TEA in the receptor agonist binding pocket that leads to a disruption of the constraining salt bridge, thereby initiating alpha(1)-AR activation.

Developing Approaches for Solving a Telecommunications Feature Subscription Problem

Call control features (e.g., call-divert, voice-mail) are primitive options to which users can subscribe off-line to personalise their service. The configuration of a feature subscription involves choosing and sequencing features from a catalogue and is subject to constraints that prevent undesirable feature interactions at run-time. When the subscription requested by a user is inconsistent, one problem is to find an optimal relaxation, which is a generalisation of the feedback vertex set problem on directed graphs, and thus it is an NP-hard task. We present several constraint programming formulations of the problem. We also present formulations using partial weighted maximum Boolean satisfiability and mixed integer linear programming. We study all these formulations by experimentally comparing them on a variety of randomly generated instances of the feature subscription problem.

Smart meter devices and the effect of feedback on residential electricity consumption: Evidence from a natural experiment in Northern Ireland

Using a unique set of data and exploiting a large-scale natural experiment, we estimate the effect of real-time usage information on residential electricity consumption in Northern Ireland. Starting in April 2002, the utility replaced prepayment meters with advanced meters that allow the consumer to track usage in real-time. We rely on this event, account for the endogeneity of price and payment plan with consumption through a plan selection correction term, and find that the provision of information is associated with a decline in electricity consumption of 11-17%. We find that the reduction is robust to different specifications, selection-bias correction methods and subsamples of the original data. The advanced metering program delivers reasonably cost-effective reductions in carbon dioxide emissions, even under the most conservative usage reduction scenarios.

Critical Dialogue in Architecture Studio: Peer Interaction and Feedback

Most tutors in architecture education regard studio-based learning to be rich in feedback due to is dialogic nature. Yet, student perceptions communicated via audits such as the UK National Student Survey appear to contradict this assumption and challenge the efficacy of design studio as a truly discursive learning setting. This paper presents findings from a collaborative study that was undertaken by the Robert Gordon University, Aberdeen, and Queen’s University Belfast that develop a deeper understanding of the role that peer interaction and dialogue plays within feedback processes, and the value that students attribute to these within the overall learning experience.

The paper adopts a broad definition of feedback, with emphasis on formative processes, and including the various kinds of dialogue that typify studio-based learning, and which constitute forms of guidance, direction, and reflection. The study adopted an ethnographic approach, gathering data on student and staff perceptions over the course of an academic year, and utilising methods embracing both quantitative and qualitative data.

The study found that the informal, socially-based peer interaction that characterises the studio is complementary to, and quite distinct from, the learning derived through tutor interaction. The findings also articulate the respective properties of informal and formally derived feedback and the contribution each makes to the quality of studio-based learning. It also identifies limitations in the use or value of peer learning, understanding of which is valuable to enhancing studio learning in architecture.