595 research outputs found
Presence and task performance:an approach in the light of cognitive style
The paper highlights the relationship between each of four bi-polar dimensions of personality cognitive style, such as extraversion–introversion, sensing–intuition, thinking–feeling and judging–perceiving, and the level of sense of presence experienced. Findings indicate that individuals who are more sensitive, more feeling or more introverted experience a higher level of presence. While not reaching statistical significance, differing cognitive styles appear to impact on task performance. The apparent negative relationship discovered between sense of presence and task performance should be considered in the light of task characteristics. We discuss the implications of these findings and how they contribute to an understanding of the complex relationship that exists between presence and task performance and how this subsequently ought to influence the design of virtual environments
A survey of agent-oriented methodologies
This article introduces the current agent-oriented methodologies. It discusses what approaches have been followed (mainly extending existing object oriented and knowledge engineering methodologies), the suitability of these approaches for agent modelling, and some conclusions drawn from the survey
Controlled assembly of SNAP-PNA-fluorophore systems on DNA templates to produce fluorescence resonance energy transfer
The SNAP protein is a widely used self-labeling tag that can be used for tracking protein localization and trafficking in living systems. A model system providing controlled alignment of SNAP-tag units can provide a new way to study clustering of fusion proteins. In this work, fluorescent SNAP-PNA conjugates were controllably assembled on DNA frameworks forming dimers, trimers, and tetramers. Modification of peptide nucleic acid (PNA) with the O6-benzyl guanine (BG) group allowed the generation of site-selective covalent links between PNA and the SNAP protein. The modified BG-PNAs were labeled with fluorescent Atto dyes and subsequently chemo-selectively conjugated to SNAP protein. Efficient assembly into dimer and oligomer forms was verified via size exclusion chromatography (SEC), electrophoresis (SDS-PAGE), and fluorescence spectroscopy. DNA directed assembly of homo- and hetero-dimers of SNAP-PNA constructs induced homo- and hetero-FRET, respectively. Longer DNA scaffolds controllably aligned similar fluorescent SNAP-PNA constructs into higher oligomers exhibiting homo-FRET. The combined SEC and homo-FRET studies indicated the 1:1 and saturated assemblies of SNAP-PNA-fluorophore:DNA formed preferentially in this system. This suggested a kinetic/stoichiometric model of assembly rather than binomially distributed products. These BG-PNA-fluorophore building blocks allow facile introduction of fluorophores and/or assembly directing moieties onto any protein containing SNAP. Template directed assembly of PNA modified SNAP proteins may be used to investigate clustering behavior both with and without fluorescent labels which may find use in the study of assembly processes in cells
Exploring Aboriginal People\u27s connection to country to strengthen human-nature theoretical perspectives
Purpose Aboriginal people across Australia have diverse practices, beliefs and knowledges based on thousands of generations of managing and protecting their lands (Country). The intimate relationship Aboriginal people have with their Country is explored in this chapter because such knowledge is important for building insight into the relationship between social and ecological systems. Often in research Aboriginal views have been marginalised from discussions focused on their lands to the detriment of ecosystems and human health. This chapter aims to understand if such marginalisation is evident in Western human–nature relationship discourses.Approach This chapter provides a critical literature review which examines whether Aboriginal people’s diverse understanding of their ecosystems have been incorporated into human–nature theories using the biophilia hypothesis as a starting point. Other concepts explored include solastalgia, topophilia and place.Findings Critiques of these terminologies in the context of Aboriginal people’s connection to Country are limited but such incorporation is viewed in the chapter as a possible mechanism for better understanding human’s connection to nature. The review identified that Aboriginal people’s relationship to Country seems to be underrepresented in the human–nature theory literature.Value This chapter emphasises that the integration of Aboriginal perspectives into research, ecological management and policy can provide better insight into the interrelationships between social and ecological systems
A cluster randomized controlled trial of the effectiveness and cost-effectiveness of Intermediate Care Clinics for Diabetes (ICCD) : study protocol for a randomized controlled trial
Background
World-wide healthcare systems are faced with an epidemic of type 2 diabetes. In the United Kingdom, clinical care is primarily provided by general practitioners (GPs) rather than hospital specialists. Intermediate care clinics for diabetes (ICCD) potentially provide a model for supporting GPs in their care of people with poorly controlled type 2 diabetes and in their management of cardiovascular risk factors. This study aims to (1) compare patients with type 2 diabetes registered with practices that have access to an ICCD service with those that have access only to usual hospital care; (2) assess the cost-effectiveness of the intervention; and (3) explore the views and experiences of patients, health professionals and other stakeholders.
Methods/Design
This two-arm cluster randomized controlled trial (with integral economic evaluation and qualitative study) is set in general practices in three UK Primary Care Trusts. Practices are randomized to one of two groups with patients referred to either an ICCD (intervention) or to hospital care (control).
Intervention group: GP practices in the intervention arm have the opportunity to refer patients to an ICCD - a multidisciplinary team led by a specialist nurse and a diabetologist. Patients are reviewed and managed in the ICCD for a short period with a goal of improving diabetes and cardiovascular risk factor control and are then referred back to practice.
or
Control group: Standard GP care, with referral to secondary care as required, but no access to ICCD.
Participants are adults aged 18 years or older who have type 2 diabetes that is difficult for their GPs to control. The primary outcome is the proportion of participants reaching three risk factor targets: HbA1c (≤7.0%); blood pressure (<140/80); and cholesterol (<4 mmol/l), at the end of the 18-month intervention period. The main secondary outcomes are the proportion of participants reaching individual risk factor targets and the overall 10-year risks for coronary heart disease(CHD) and stroke assessed by the United Kingdom Prospective Diabetes Study (UKPDS) risk engine. Other secondary outcomes include body mass index and waist circumference, use of medication, reported smoking, emotional adjustment, patient satisfaction and views on continuity, costs and health related quality of life. We aimed to randomize 50 practices and recruit 2,555 patients
Water velocity limits the temporal extent of herbivore effects on aquatic plants in a lowland river
The role of herbivores in regulating aquatic plant dynamics has received growing recognition from researchers and managers. However, the evidence for herbivore impacts on aquatic plants is largely based on short-term exclosure studies conducted within a single plant growing season. Thus, it is unclear how long herbivore impacts on aquatic plant abundance can persist for. We addressed this knowledge gap by testing whether mute swan (Cygnus olor) grazing on lowland river macrophytes could be detected in the following growing season. Furthermore, we investigated the role of seasonal changes in water current speed in limiting the temporal extent of grazing. We found no relationship between swan biomass density in 1 year and aquatic plant cover or biomass in the following spring. No such carry-over effects were detected despite observing high swan biomass densities in the previous year from which we inferred grazing impacts on macrophytes. Seasonal increases in water velocity were associated with reduced grazing pressure as swans abandoned river habitat. Furthermore, our study highlights the role of seasonal changes in water velocity in determining the length of the mute swan grazing season in shallow lowland rivers and thus in limiting the temporal extent of herbivore impacts on aquatic plant abundance
Reconstructing disease transmission dynamics from animal movements and test data
Disease outbreaks are often accompanied by a wealth of data, usually in the form of movements, locations and tests. This data is a valuable resource in which data scientists and epidemiologists can reconstruct the transmission pathways and parameters and thus devise control strategies. However, the spatiotemporal data gathered can be both vast whilst at the same time incomplete or contain errors frustrating the effort to accurately model the transmission processes. Fortunately, several techniques exist that can be used to infer the relevant information to help explain these processes. The aim of this article is to provide the reader with a user friendly introduction to the techniques used in dealing with the large datasets that exists in epidemiological and ecological science and the common pitfalls that are to be avoided as well as an introduction to inference techniques for estimating parameter values for mathematical models from spatiotemporal datasets
Application of Graphene within Optoelectronic Devices and Transistors
Scientists are always yearning for new and exciting ways to unlock graphene's
true potential. However, recent reports suggest this two-dimensional material
may harbor some unique properties, making it a viable candidate for use in
optoelectronic and semiconducting devices. Whereas on one hand, graphene is
highly transparent due to its atomic thickness, the material does exhibit a
strong interaction with photons. This has clear advantages over existing
materials used in photonic devices such as Indium-based compounds. Moreover,
the material can be used to 'trap' light and alter the incident wavelength,
forming the basis of the plasmonic devices. We also highlight upon graphene's
nonlinear optical response to an applied electric field, and the phenomenon of
saturable absorption. Within the context of logical devices, graphene has no
discernible band-gap. Therefore, generating one will be of utmost importance.
Amongst many others, some existing methods to open this band-gap include
chemical doping, deformation of the honeycomb structure, or the use of carbon
nanotubes (CNTs). We shall also discuss various designs of transistors,
including those which incorporate CNTs, and others which exploit the idea of
quantum tunneling. A key advantage of the CNT transistor is that ballistic
transport occurs throughout the CNT channel, with short channel effects being
minimized. We shall also discuss recent developments of the graphene tunneling
transistor, with emphasis being placed upon its operational mechanism. Finally,
we provide perspective for incorporating graphene within high frequency
devices, which do not require a pre-defined band-gap.Comment: Due to be published in "Current Topics in Applied Spectroscopy and
the Science of Nanomaterials" - Springer (Fall 2014). (17 pages, 19 figures
The injecting ‘event’: harm reduction beyond the human
Since the 1980s, the primary public health response to injecting drug use in the UK has been one of harm reduction. That is, reducing the harms associated with drug use without necessarily reducing consumption itself. Rooted in a post-Enlightenment idea of rationalism, interventions are premised on the rational individual who, given the right means, will choose to avoid harm. This lies in stark contrast to dominant addiction models that pervade popular images of the ‘out of control’ drug user, or worse, ‘junkie’. Whilst harm reduction has undoubtedly had vast successes, including challenging the otherwise pathologising and often stigmatising model of addiction, I argue that it has not gone far enough in addressing aspects of drug use that go beyond ‘rational’ and ‘human’ control. Drawing on my doctoral research with people who inject drugs, conducted in London, UK, this paper highlights the role of the injecting ‘event’, which far from being directed or controlled by a pre-defined individual or ‘body’ was composed by a fragile assemblage of bodies, human and nonhuman. Furthermore, in line with the ‘event’s’ heterogeneous and precarious make-up, multiple ways of ‘becoming’ through these events were possible. I look here at these ‘becomings’ as both stabilising and destabilising ways of being in the world, and argue that we need to pay closer attention to these events and what people are actually in the process of becoming in order to enact more accountable and ‘response-able’ harm reduction
Specific ion channels contribute to key elements of pathology during secondary degeneration following neurotrauma
Background: Following partial injury to the central nervous system, cells beyond the initial injury site undergo secondary degeneration, exacerbating loss of neurons, compact myelin and function. Changes in Ca 2+ flux are associated with metabolic and structural changes, but it is not yet clear how flux through specific ion channels contributes to the various pathologies. Here, partial optic nerve transection in adult female rats was used to model secondary degeneration. Treatment with combinations of three ion channel inhibitors was used as a tool to investigate which elements of oxidative and structural damage related to long term functional outcomes. The inhibitors employed were the voltage gated Ca 2+ channel inhibitor Lomerizine (Lom), the Ca 2+ permeable AMPA receptor inhibitor YM872 and the P2X 7 receptor inhibitor oxATP. Results: Following partial optic nerve transection, hyper-phosphorylation of Tau and acetylated tubulin immunoreactivity were increased, and Nogo-A immunoreactivity was decreased, indicating that axonal changes occurred acutely. All combinations of ion channel inhibitors reduced hyper-phosphorylation of Tau and increased Nogo-A immunoreactivity at day 3 after injury. However, only Lom/oxATP or all three inhibitors in combination significantly reduced acetylated tubulin immunoreactivity. Most combinations of ion channel inhibitors were effective in restoring the lengths of the paranode and the paranodal gap, indicative of the length of the node of Ranvier, following injury. However, only all three inhibitors in combination restored to normal Ankyrin G length at the node of Ranvier. Similarly, HNE immunoreactivity and loss of oligodendrocyte precursor cells were only limited by treatment with all three ion channel inhibitors in combination. Conclusions: Data indicate that inhibiting any of a range of ion channels preserves certain elements of axon and node structure and limits some oxidative damage following injury, whereas ionic flux through all three channels must be inhibited to prevent lipid peroxidation and preserve Ankyrin G distribution and OPCs
- …