40,928 research outputs found
Searching for a talking face: the effect of degrading the auditory signal
Previous research (e.g. McGurk and MacDonald, 1976) suggests that faces and voices are bound automatically, but recent evidence suggests that attention is involved in a task of searching for a talking face (Alsius and Soto-Faraco, 2011). We hypothesised that the processing demands of the stimuli may affect the amount of attentional resources required, and investigated what effect degrading the auditory stimulus had on the time taken to locate a talking face. Twenty participants were presented with between 2 and 4 faces articulating different sentences, and had to decide which of these faces matched the sentence that they heard. The results showed that in the least demanding auditory condition (clear speech in quiet), search times did not significantly increase when the number of faces increased. However, when speech was presented in background noise or was processed to simulate the information provided by a cochlear implant, search times increased as the number of faces increased. Thus, it seems that the amount of attentional resources required vary according to the processing demands of the auditory stimuli, and when processing load is increased then faces need to be individually attended to in order to complete the task. Based on these results we would expect cochlear-implant users to find the task of locating a talking face more attentionally demanding than normal hearing listeners
Cosmological Constraints on Dark Energy Models
Modified gravity theories with the Gauss-Bonnet term
have
recently gained a lot of attention as a possible explanation of dark energy. We
perform a thorough phase space analysis on the so-called models, where
is some general function of the Gauss-Bonnet term, and derive conditions
for the cosmological viability of dark energy models. Following the
case, we show that these conditions can be nicely presented as
geometrical constraints on the derivatives of . We find that for general
models there are two kinds of stable accelerated solutions, a de Sitter
solution and a phantom-like solution. They co-exist with each other and which
solution the universe evolves to depends on the initial conditions. Finally,
several toy models of dark energy are explored. Cosmologically viable
trajectories that mimic the CDM model in the radiation and matter
dominated periods, but have distinctive signatures at late times, are obtained.Comment: 17 pages, 3 figures; typos correcte
Vitamins Reverse Endothelial Dysfunction Through Regulation of eNOS and NAD(P)H Oxidase Activities
Antioxidant vitamins C and E have protective properties in genetic hypertension associated with enhanced
oxidative stress. This study investigated whether vitamins C and/or E modulate vascular function by regulating
enzymatic activities of endothelial nitric oxide synthase (eNOS) and NAD(P)H oxidase using thoracic aortas of 20- to
22-week-old male spontaneously hypertensive rats (SHR) and their matched normotensive counterparts, Wistar-Kyoto
rats (WKY). SHR aortas had impaired relaxant responses to acetylcholine but not to sodium nitroprusside, despite an
2-fold increase in eNOS activity and NO release. The levels of superoxide anion (O2
), a potent NO scavenger, and
NAD(P)H oxidase activity were also 2-fold higher in SHR aortas. Mechanical but not pharmacological inactivation of
endothelium (by rubbing and 100 mol/L L-NAME, respectively) significantly abrogated O2
in both strains.
Treatments of SHR aortas with NAD(P)H oxidase inhibitors, namely diphenyleneiodinium and apocynin, significantly
diminished O2
production. The incubation of SHR aortas with different concentrations of vitamin C (10 to 100 mol/L)
and specifically with high concentrations of vitamin E (100 mol/L) improved endothelial function, reduced superoxide
production as well as NAD(P)H oxidase activity, and increased eNOS activity and NO generation in SHR aortas to the
levels observed in vitamin C- and E-treated WKY aortas. Our results reveal endothelial NAD(P)H oxidase as the major
source of vascular O2
in SHR and also show that vitamins C and E are critical in normalizing genetic endothelial
dysfunction through regulation of eNOS and NAD(P)H oxidase activities
Spectral synthesis for Banach Algebras II
This paper continues the study of spectral synthesis and the topologies tau-infinity and tau-r on the ideal space of a Banach algebra, concentrating particularly on the class of Haagerup tensor products of C*-algebras. For this class, it is shown that spectral synthesis is equivalent to the Hausdorffness of tau_infinity. Under a weak extra condition, spectral synthesis is shown to be equivalent to the Hausdorffness of tau_r
Changing international health policy and changing international development goals
The World Health Organisation (WHO) was founded in 1948 with a remit to promote public health around the world. The WHO’s constitution sets out its objective as ‘the attainment by all peoples of the highest possible level of health’ (WHO, 1948). The paper raises broad questions over the aspirations and practice of international health policy in its international political and development context. The paper explores how international health policy has been informed by evolving international development strategies, from the earlier modernisation approaches to the sustainable development approaches of recent decades. The final part considers international health policy today in a world of continuing international inequalities
Towns conquer: a gamified application to collect geographical names (vernacular names/toponyms)
The traditional model for geospatial crowd sourcing asks the public to use their free time collecting geospatial data for no obvious reward. This model has shown to work very well on projects such as Open Street Map, but comes with some clear disadvantages such as reliance on small communities of ‘Neo-geographers’ and variability in quality and content of collected data. This project aims at tackling these problems by providing alternative motivation specifically a smartphone based computer game service. Geographical names (vernacular names/ toponyms) have been identified as potential targets as they are difficult to collect on a large scale and easy to collect locally, thus ideal for crowd sourcing. The data set will be a toponyms database provided by the Spanish National Geographic Institute (IGN Spain). A location based game is targeted as it is easy to guide data collection with in-game rewards (prizes, points, badges etc.). Android is chosen for its accessible API and wide use
Self-tuning and the derivation of the Fab Four
We have recently proposed a special class of scalar tensor theories known as
the Fab Four. These arose from attempts to analyse the cosmological constant
problem within the context of Horndeski's most general scalar tensor theory.
The Fab Four together give rise to a model of self-tuning, with the relevant
solutions evading Weinberg's no-go theorem by relaxing the condition of
Poincare invariance in the scalar sector. The Fab Four are made up of four
geometric terms in the action with each term containing a free potential
function of the scalar field. In this paper we rigorously derive this model
from the general model of Horndeski, proving that the Fab Four represents the
only classical scalar tensor theory of this type that has any hope of tackling
the cosmological constant problem. We present the full equations of motion for
this theory, and give an heuristic argument to suggest that one might be able
to keep radiative corrections under control. We also give the Fab Four in terms
of the potentials presented in Deffayet et al's version of Horndeski.Comment: 25 pages, 1 figur
Deception and self-awareness
This paper presents a study conducted for the Shades of Grey EPSRC research project (EP/H02302X/1), which aims to develop a suite of interventions for identifying terrorist activities. The study investigated the body movements demonstrated by participants while waiting to be interviewed, in one of two conditions: preparing to lie or preparing to tell the truth. The effect of self-awareness was also investigated, with half of the participants sitting in front of a full length mirror during the waiting period. The other half faced a blank wall. A significant interaction was found for the duration of hand/arm movements between the deception and self-awareness conditions (F=4.335, df=1;76, p<0.05). Without a mirror, participants expecting to lie spent less time moving their hands than those expecting to tell the truth; the opposite was seen in the presence of a mirror. This finding indicates a new research area worth further investigation
- …