Automatic infrasound signal detection using the Hough transform

The Hough transform is a mathematical device that allows the retrieval of parametric curve information from binary-pixelated data in the presence of noise. This slope-intercept transform maps each point in the image space S into a straight line in parameter space P and has the very useful property that all points in S that lie along the same straight-line map to the same number of straight lines in P with a common intersection point. Thus with a suitable counting procedure, the problem of extended straight-line detection in noisy pixelated data becomes one of local peak finding, a problem that may be substantially more tractable. In this study, an algorithm that utilizes the Hough transform for the detection of signals in International Monitoring System style infrasonic array data by seeking periods of constant backazimuth that are associated with coherent acoustic signals is described. A system of synthetic signal implants is used to assess the performance of the detection algorithm by generating a set of pseudo Receiver Operator Characteristic curves. A feature of the detection algorithm is the ability to accommodate full three-dimensional array geometry

Student responses to delivery modes in a large first year mathematics unit

KEYWORDS: Lecture Capture, Online Lectures, Delivery Methods Background Many higher education providers now routinely capture all lectures in a unit and make these recordings available through Learning Management Systems to students enrolled in the unit. This practice has led to student expectations that recorded lectures will be available in most, if not all, of their units. Within mathematics the question arises as to which delivery mode for lectures will contribute best to student learning in this environment. Aims The aim of this study was to compare two different delivery modes for a large first year mathematics unit. We wanted to discover whether there was a student preference for the style of lecture captured and the reasons for those preferences. We were also interested in the students’ perception of the value of different methods of delivery. Description of intervention The unit was taught by two staff with one staff member using a tablet PC to deliver lectures and the other using slides who also made use of a bench camera to digitally transmit some additional worked examples. Design and methods This study is part of a larger research project looking at the effectiveness of online lectures in a tertiary mathematics setting. The project employs questionnaires and interviews with students studying a pre-service mathematics unit for intending primary teachers. Together with examining entire class records, we conducted online surveys at the end of semester. There were 384 students enrolled in the unit with 75 responding to the online survey. The questions that will be discussed included a number of statements with Likert responses and some open-ended questions. Results On the whole, students expressed a preference for the lectures delivered using the tablet PC with some important qualifications. The reasons for this preference were mainly due to the ability of the students to engage with the arguments and processes as they were discussed. Conclusions With the increasing use of lecture capture, serious consideration needs to be given to the type of lecture delivery that will lead to the best learning outcomes for students which may vary from discipline to discipline. While the participants in this study were pre service primary teachers, the reasons they gave for preferring for the tablet PC lectures would be valid in any large first year mathematics lecture. Proceedings of the Australian Conference on Science and Mathematics Education, Curtin University, Sept 30th to Oct 1st, 2015, page X, ISBN Number 978-0-9871834-4-6

El multiculturalisme en les polítiques esportives : anàlisi de l'adequació de les polítiques locals a Catalunya a les actuacions promogudes per la Unió Europea

Informe final de l'estudi finançat pel Patronat Català Pro-Europa (2007). Recull una investigació qualitativa a l'entorn de les polítiques i actuacions promogudes des de les administracions públiques catalanes per a la provisió d'ofertes esportives en el context multicultural emergent a Catalunya, així com l'anàlisi de l'aplicació dels principis bàsics establerts a nivell europeu en aquest àmbit

Networking in olympic studies : current situation and proposals for development and cooperation

Executive report of the research project commissioned by the Department of Information Management of the International Olympic Committee (IOC) to CEO-UAB to develop a study about Olympic Studies on a global scale to analyse the opportunity for the IOC to promote an international network in Olympic Studies (2004-2005). The main goals of the UAB's study were to identify actors and opportunities for the development of Olympic Studies within the network and to make recommendations as to the strategic and practical management of this network to maximize its effectiveness in promoting cooperation

Crossmodal visual-tactile extinction: Modulation by posture implicates biased competition in proprioceptively reconstructed space

Extinction is a common consequence of unilateral brain injury: contralesional events can be perceived in isolation, yet are missed when presented concurrently with competing events on the ipsilesional side. This can arise crossmodally, where a contralateral touch is extinguished by an ipsilateral visual event. Recent studies showed that repositioning the hands in visible space, or making visual events more distant, can modulate such crossmodal extinction. Here, in a detailed single-case study, we implemented a novel spatial manipulation when assessing crossmodal extinction. This was designed not only to hold somatosensory inputs and hand/arm-posture constant, but also to hold (retinotopic) visual inputs constant, yet while still changing the spatial relationship of tactile and visual events in the external world. Our right hemisphere patient extinguished left-hand touches due to visual stimulation of the right visual field (RVF) when tested in the usual default posture with eyes/head directed straight ahead. But when her eyes/head were turned to the far left (and any visual events shifted along with this), such that the identical RVF retinal stimulation now fell at the same external location as the left-hand touch, crossmodal extinction was eliminated. Since only proprioceptive postural cues could signal this changed spatial relationship for the critical condition, our results show for the first time that such postural cues alone are sufficient to modulate crossmodal extinction. Identical somatosensory and retinal inputs can lead to severe crossmodal extinction, or none, depending on current posture

Spatially valid proprioceptive cues improve the detection of a visual stimulus

Vision and proprioception are the main sensory modalities that convey hand location and direction of movement. Fusion of these sensory signals into a single robust percept is now well documented. However, it is not known whether these modalities also interact in the spatial allocation of attention, which has been demonstrated for other modality pairings. The aim of this study was to test whether proprioceptive signals can spatially cue a visual target to improve its detection. Participants were instructed to use a planar manipulandum in a forward reaching action and determine during this movement whether a near-threshold visual target appeared at either of two lateral positions. The target presentation was followed by a masking stimulus, which made its possible location unambiguous, but not its presence. Proprioceptive cues were given by applying a brief lateral force to the participant’s arm, either in the same direction (validly cued) or in the opposite direction (invalidly cued) to the on-screen location of the mask. The d′ detection rate of the target increased when the direction of proprioceptive stimulus was compatible with the location of the visual target compared to when it was incompatible. These results suggest that proprioception influences the allocation of attention in visual spac

Short-Term Visual Deprivation Does Not Enhance Passive Tactile Spatial Acuity

An important unresolved question in sensory neuroscience is whether, and if so with what time course, tactile perception is enhanced by visual deprivation. In three experiments involving 158 normally sighted human participants, we assessed whether tactile spatial acuity improves with short-term visual deprivation over periods ranging from under 10 to over 110 minutes. We used an automated, precisely controlled two-interval forced-choice grating orientation task to assess each participant's ability to discern the orientation of square-wave gratings pressed against the stationary index finger pad of the dominant hand. A two-down one-up staircase (Experiment 1) or a Bayesian adaptive procedure (Experiments 2 and 3) was used to determine the groove width of the grating whose orientation each participant could reliably discriminate. The experiments consistently showed that tactile grating orientation discrimination does not improve with short-term visual deprivation. In fact, we found that tactile performance degraded slightly but significantly upon a brief period of visual deprivation (Experiment 1) and did not improve over periods of up to 110 minutes of deprivation (Experiments 2 and 3). The results additionally showed that grating orientation discrimination tends to improve upon repeated testing, and confirmed that women significantly outperform men on the grating orientation task. We conclude that, contrary to two recent reports but consistent with an earlier literature, passive tactile spatial acuity is not enhanced by short-term visual deprivation. Our findings have important theoretical and practical implications. On the theoretical side, the findings set limits on the time course over which neural mechanisms such as crossmodal plasticity may operate to drive sensory changes; on the practical side, the findings suggest that researchers who compare tactile acuity of blind and sighted participants should not blindfold the sighted participants

The Beaker phenomenon and the genomic transformation of northwest Europe

From around 2750 to 2500 bc, Bell Beaker pottery became widespread across western and central Europe, before it disappeared between 2200 and 1800 bc. The forces that propelled its expansion are a matter of long-standing debate, and there is support for both cultural diffusion and migration having a role in this process. Here we present genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 individuals associated with Beaker-complex artefacts. We detected limited genetic affinity between Beaker-complex-associated individuals from Iberia and central Europe, and thus exclude migration as an important mechanism of spread between these two regions. However, migration had a key role in the further dissemination of the Beaker complex. We document this phenomenon most clearly in Britain, where the spread of the Beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain’s gene pool within a few hundred years, continuing the east-to-west expansion that had brought steppe-related ancestry into central and northern Europe over the previous centuries