Processing of short auditory stimuli:The rapid audio sequential presentation paradigm (RASP)

Human listeners seem to be remarkably able to recognise acoustic sound sources based on timbre cues. Here we describe a psychophysical paradigm to estimate the time it takes to recognise a set of complex sounds differing only in timbre cues: both in terms of the minimum duration of the sounds and the inferred neural processing time. Listeners had to respond to the human voice while ignoring a set of distractors. All sounds were recorded from natural sources over the same pitch range and equalised to the same duration and power. In a first experiment, stimuli were gated in time with a raised-cosine window of variable duration and random onset time. A voice/non-voice (yes/no) task was used. Performance, as measured by d', remained above chance for the shortest sounds tested (2 ms); d's above 1 were observed for durations longer than or equal to 8 ms. Then, we constructed sequences of short sounds presented in rapid succession. Listeners were asked to report the presence of a single voice token that could occur at a random position within the sequence. This method is analogous to the "rapid sequential visual presentation" paradigm (RSVP), which has been used to evaluate neural processing time for images. For 500-ms sequences made of 32-ms and 16-ms sounds, d' remained above chance for presentation rates of up to 30 sounds per second. There was no effect of the pitch relation between successive sounds: identical for all sounds in the sequence or random for each sound. This implies that the task was not determined by streaming or forward masking, as both phenomena would predict better performance for the random pitch condition. Overall, the recognition of familiar sound categories such as the voice seems to be surprisingly fast, both in terms of the acoustic duration required and of the underlying neural time constants.

An audit of drug shortages in a community pharmacy practice

Background: There are no firm data on drug shortages in Irish community pharmacy. This prospective observational study aimed to characterise the drug shortage problem in an Irish community pharmacy.
Aims: The primary aim was to determine numbers and durations of drug shortages. Secondary aims included comparing these shortages with Irish Pharmacy Union (IPU) drug shortage lists and determining the frequency with which notifications were received prior to shortages. Further secondary aims were to examine relationships between causes of drug shortages and drug costs and between causes of drug shortages and shortage durations.
Methods: The study took place in a community pharmacy in a Limerick City suburb between October 2012 and February 2013. Data were collected daily regarding drugs that were dispensed, but unavailable to purchase. Suppliers/manufacturers provided data on the reasons for shortages.
Results: 65/1,232 dispensed drugs (5.3 %) were in short supply over the study period. Median shortage duration was 13 days (interquartile range 4–32 days) and median cost was €8.10. Numbers of unavailable drugs by month varied from 13 to 38. Monthly IPU drug shortage lists identified between six and eight of these shortages depending on the month. Two notifications were received from suppliers/manufacturers regarding shortages. Parallel exports had the highest mean costs (mean €38.05) and manufacturing problems were associated with the longest durations (mean 57.44 days).
Conclusions: This study highlights the drug shortage problem in an Irish community pharmacy. We propose that enhanced communication between all stakeholders is the most worthwhile solution. Further studies are needed.

Nanosecond imaging of shock-and jet-like features

The production of shock- and collimated jet-like features is recorded from the self-emission of a plasma using a 16- frame camera, which can show the progression of the interaction over short (100s ns) durations. A cluster of laser beams, with intensity 10¹⁵ W/cm², was focused onto a planar aluminum foil to produce a plasma that expanded into 0.7 mbar of argon gas. The acquisition of 16 ultrafast images on a single shot allows prompt spatial and temporal characterization of the plasma and enables the velocity of the jet- and shock-like features to be calculated.

Moving with Beats and Loops: The Structure of Auditory Events and Sensorimotor Timing

Traditionally, audio-motor timing processes have been understood as motor output from an internal clock, the speed of which is set by heard sound pulses. In contrast, this paper proposes a more ecologically-grounded approach, arguing that audio-motor processes are better characterized as performed actions on the perceived structure of auditory events. This position is explored in the context of auditory sensorimotor synchronization and continuation timing. Empirical research shows that the structure of sounds as auditory events can lead to marked differences in movement timing performance. The nature of these effects is discussed in the context of perceived action-relevance of auditory event structure. It is proposed that different forms of sound invite or support different patterns of sensorimotor timing. Hence, the temporal information in looped auditory signals is more than just the interval durations between onsets: all metronomes are not created equal. The potential implications for auditory guides in motor performance enhancement are also described.

A Bayesian method for detecting stellar flares

We present a Bayesian-odds-ratio-based algorithm for detecting stellar flares in light-curve data. We assume flares are described by a model in which there is a rapid rise with a half-Gaussian profile, followed by an exponential decay. Our signal model also contains a polynomial background model required to fit underlying light-curve variations in the data, which could otherwise partially mimic a flare. We characterize the false alarm probability and efficiency of this method under the assumption that any unmodelled noise in the data is Gaussian, and compare it with a simpler thresholding method based on that used in Walkowicz et al. We find our method has a significant increase in detection efficiency for low signal-to-noise ratio (S/N) flares. For a conservative false alarm probability our method can detect 95 per cent of flares with S/N less than 20, as compared to S/N of 25 for the simpler method. We also test how well the assumption of Gaussian noise holds by applying the method to a selection of 'quiet' Kepler stars. As an example we have applied our method to a selection of stars in Kepler Quarter 1 data. The method finds 687 flaring stars with a total of 1873 flares after vetos have been applied. For these flares we have made preliminary characterizations of their durations and and S/N.

How Video Lecture Capture affects Student Engagement in a University Computer Programming Course: Attendance, Video Viewing Behaviours and Student Attitudes

Introduction
The use of video capture of lectures in Higher Education is not a recent occurrence with web based learning technologies including digital recording of live lectures becoming increasing commonly offered by universities throughout the world (Holliman and Scanlon, 2004). However in the past decade the increase in technical infrastructural provision including the availability of high speed broadband has increased the potential and use of videoed lecture capture. This had led to a variety of lecture capture formats including pod casting, live streaming or delayed broadcasting of whole or part of lectures.
Additionally in the past five years there has been a significant increase in the popularity of online learning, specifically via Massive Open Online Courses (MOOCs) (Vardi, 2014). One of the key aspects of MOOCs is the simulated recording of lecture like activities. There has been and continues to be much debate on the consequences of the popularity of MOOCs, especially in relation to its potential uses within established University programmes.
There have been a number of studies dedicated to the effects of videoing lectures.
The clustered areas of research in video lecture capture have the following main themes:
• Staff perceptions including attendance, performance of students and staff workload
• Reinforcement versus replacement of lectures
• Improved flexibility of learning
• Facilitating engaging and effective learning experiences
• Student usage, perception and satisfaction
• Facilitating students learning at their own pace
Most of the body of the research has concentrated on student and faculty perceptions, including academic achievement, student attendance and engagement (Johnston et al, 2012).
Generally the research has been positive in review of the benefits of lecture capture for both students and faculty. This perception coupled with technical infrastructure improvements and student demand may well mean that the use of video lecture capture will continue to increase in frequency in the next number of years in tertiary education. However there is a relatively limited amount of research in the effects of lecture capture specifically in the area of computer programming with Watkins 2007 being one of few studies . Video delivery of programming solutions is particularly useful for enabling a lecturer to illustrate the complex decision making processes and iterative nature of the actual code development process (Watkins et al 2007). As such research in this area would appear to be particularly appropriate to help inform debate and future decisions made by policy makers.
Research questions and objectives
The purpose of the research was to investigate how a series of lecture captures (in which the audio of lectures and video of on-screen projected content were recorded) impacted on the delivery and learning of a programme of study in an MSc Software Development course in Queen’s University, Belfast, Northern Ireland. The MSc is conversion programme, intended to take graduates from non-computing primary degrees and upskill them in this area. The research specifically targeted the Java programming module within the course. It also analyses and reports on the empirical data from attendances and various video viewing statistics. In addition, qualitative data was collected from staff and student feedback to help contextualise the quantitative results.
Methodology, Methods and Research Instruments Used
The study was conducted with a cohort of 85 post graduate students taking a compulsory module in Java programming in the first semester of a one year MSc in Software Development. A pre-course survey of students found that 58% preferred to have available videos of “key moments” of lectures rather than whole lectures. A large scale study carried out by Guo concluded that “shorter videos are much more engaging” (Guo 2013). Of concern was the potential for low audience retention for videos of whole lectures.
The lecturers recorded snippets of the lecture directly before or after the actual physical delivery of the lecture, in a quiet environment and then upload the video directly to a closed YouTube channel. These snippets generally concentrated on significant parts of the theory followed by theory related coding demonstration activities and were faithful in replication of the face to face lecture. Generally each lecture was supported by two to three videos of durations ranging from 20 – 30 minutes.
Attendance
The MSc programme has several attendance based modules of which Java Programming was one element. In order to assess the consequence on attendance for the Programming module a control was established. The control used was a Database module which is taken by the same students and runs in the same semester.
Access engagement
The videos were hosted on a closed YouTube channel made available only to the students in the class. The channel had enabled analytics which reported on the following areas for all and for each individual video; views (hits), audience retention, viewing devices / operating systems used and minutes watched.
Student attitudes
Three surveys were taken in regard to investigating student attitudes towards the videoing of lectures. The first was before the start of the programming module, then at the mid-point and subsequently after the programme was complete.
The questions in the first survey were targeted at eliciting student attitudes towards lecture capture before they had experienced it in the programme. The midpoint survey gathered data in relation to how the students were individually using the system up to that point. This included feedback on how many videos an individual had watched, viewing duration, primary reasons for watching and the result on attendance, in addition to probing for comments or suggestions. The final survey on course completion contained questions similar to the midpoint survey but in summative view of the whole video programme.
Conclusions and Outcomes
The study confirmed findings of other such investigations illustrating that there is little or no effect on attendance at lectures. The use of the videos appears to help promote continual learning but they are particularly accessed by students at assessment periods. Students respond positively to the ability to access lectures digitally, as a means of reinforcing learning experiences rather than replacing them. Feedback from students was overwhelmingly positive indicating that the videos benefited their learning. Also there are significant benefits to part recording of lectures rather than recording whole lectures. The behaviour viewing trends analytics suggest that despite the increase in the popularity of online learning via MOOCs and the promotion of video learning on mobile devices in fact in this study the vast majority of students accessed the online videos at home on laptops or desktops However, in part, this is likely due to the nature of the taught subject, that being programming.
The research involved prerecording the lecture in smaller timed units and then uploading for distribution to counteract existing quality issues with recording entire live lectures. However the advancement and consequential improvement in quality of in situ lecture capture equipment may well help negate the need to record elsewhere. The research has also highlighted an area of potentially very significant use for performance analysis and improvement that could have major implications for the quality of teaching. A study of the analytics of the viewings of the videos could well provide a quick response formative feedback mechanism for the lecturer. If a videoed lecture either recorded live or later is a true reflection of the face to face lecture an analysis of the viewing patterns for the video may well reveal trends that correspond with the live delivery.

Duration-dependent effects of the BDNF Val66Met polymorphism on anodal tDCS induced motor cortex plasticity in older adults: a group and individual perspective

The brain derived neurotrophic factor (BDNF) Val66Met polymorphism and stimulation duration are thought to play an important role in modulating motor cortex plasticity induced by non-invasive brain stimulation (NBS). In the present study we sought to determine whether these factors interact or exert independent effects in older adults. Fifty-four healthy older adults (mean age = 66.85 years) underwent two counterbalanced sessions of 1.5 mA anodal transcranial direct current stimulation (atDCS), applied over left M1 for either 10 or 20 min. Single pulse transcranial magnetic stimulation (TMS) was used to assess corticospinal excitability (CSE) before and every 5 min for 30 min following atDCS. On a group level, there was an interaction between stimulation duration and BDNF genotype, with Met carriers (n = 13) showing greater post-intervention potentiation of CSE compared to Val66Val homozygotes homozygotes (n = 37) following 20 min (p = 0.002) but not 10 min (p = 0.219) of stimulation. Moreover, Met carriers, but not Val/Val homozygotes, exhibited larger responses to TMS (p = 0.046) after 20 min atDCS, than following 10 min atDCS. On an individual level, two-step cluster analysis revealed a considerable degree of inter-individual variability, with under half of the total sample (42%) showing the expected potentiation of CSE in response to atDCS across both sessions. Intra-individual variability in response to different durations of atDCS was also apparent, with one-third of the total sample (34%) exhibiting LTP-like effects in one session but LTD-like effects in the other session. Both the inter-individual (p = 0.027) and intra-individual (p = 0.04) variability was associated with BDNF genotype. In older adults, the BDNF Val66Met polymorphism along with stimulation duration appears to play a role in modulating tDCS-induced motor cortex plasticity. The results may have implications for the design of NBS protocols for healthy and diseased aged populations.

Testing the channel-based model of duration perception

The channel-based model of duration perception postulates the existence of neural mechanisms that respond selectively to a narrow range of stimulus durations centred on their preferred duration (Heron et al Proceedings of the Royal Society B 279 690–698). In principle the channel-based model could
explain recent reports of adaptation-induced, visual duration compression effects (Johnston et al Current Biology 16 472–479; Curran and Benton Cognition 122 252–257); from this perspective duration compression is a consequence of the adapting stimuli being presented for a longer duration than the test stimuli. In the current experiment observers adapted to a sequence of moving random dot patterns at the same retinal position, each 340ms in duration and separated by a variable (500–1000ms) interval. Following adaptation observers judged the duration of a 600ms test stimulus at the same location. The test stimulus moved in the same, or opposite, direction as the adaptor. Contrary to the channel-based
model’s prediction, test stimulus duration appeared compressed, rather than expanded, when it moved in the same direction as the adaptor. That test stimulus duration was not distorted when moving in the opposite direction further suggests that visual timing mechanisms are influenced by additional neural processing associated with the stimulus being timed.

Validity of model devices used to assess canine temperament in behavioral tests

Temperament tests are widely accepted as instruments for profiling behavioral variability in dogs, and they are applied in numerous areas of investigation (e.g. suitability for adoption or for breeding). During testing, to elicit a dog's reaction toward novel stimuli and predict its behavior in everyday life, model devices such as a child-like doll, or a fake dog, are often employed. However, the reliability of these devices to accurately stimulate dogs' reactions to children or dogs, is unknown and perhaps overestimated. This may be a particular concern in the case of aggressive behavior toward humans, a significant public health issue. The aim of this study was to: (1) evaluate the correlation between dogs' reactions to these devices, and owners' reports of their dog's aggression history (using the C-BARQ ??); (2) compare reactions toward the devices of dogs with and without histories of aggression. Subjects were selected among those visiting for behavioral consultation at the Veterinary Hospital of the University of Pennsylvania, and previously categorized as aggressive toward unfamiliar children, conspecifics, or as non-aggressive dogs (control). The test consisted of different components: an unfamiliar female tester approaching the dog; the presentation of a child-like doll, an ambiguous object, and a fake plastic dog. All tests were videotaped and durations of behaviors were later analyzed on the basis of a specified ethogram. Dogs' reactions were compared to C-BARQ scores, and interesting correlations emerged for 'dog-directed aggression/fear' (R = 0.48, P = 0.004), and 'stranger-directed aggression' (R = 0.58, P <0.001) factors. Dogs differed in their reactions toward the devices: the child-like doll and the fake dog elicited more social behaviors than the ambiguous object used as a control stimulus. Issues concerning the reliability of these tools to assess canine temperament are discussed. ?? 2012 Elsevier B.V. All rights reserved.

Picosecond metrology of laser-driven proton bursts

Tracking primary radiation-induced processes in matter requires ultrafast sources and high precision timing. While compact laser-driven ion accelerators are seeding the development of novel high instantaneous flux applications, combining the ultrashort ion and laser pulse durations with their inherent synchronicity to trace the real-time evolution of initial damage events has yet to be realized. Here we report on the absolute measurement of proton bursts as short as 3.5±0.7 ps from laser solid target interactions for this purpose. Our results verify that laser-driven ion acceleration can deliver interaction times over a factor of hundred shorter than those of state-of-the-art accelerators optimized for high instantaneous flux. Furthermore, these observations draw ion interaction physics into the field of ultrafast science, opening the opportunity for quantitative comparison with both numerical modelling and the adjacent fields of ultrafast electron and photon interactions in matter.

Adapting to time: duration channels do not mediate human time perception

Accurately encoding the duration and temporal order of events is essential for survival and important to everyday activities, from holding conversations to driving in fast flowing traffic. Although there is a growing body of evidence that the timing of brief events (< 1s) is encoded by modality-specific mechanisms, it is not clear how such mechanisms register event duration. One approach gaining traction is a channel-based model; this envisages narrowly-tuned, overlapping timing mechanisms that respond preferentially to different durations. The channel-based model predicts that adapting to a given event duration will result in overestimating and underestimating the duration of longer and shorter events, respectively. We tested the model by having observers judge the duration of a brief (600ms) visual test stimulus following adaptation to longer (860ms) and shorter (340ms) stimulus durations. The channel-based model predicts perceived duration compression of the test stimulus in the former condition and perceived duration expansion in the latter condition. Duration compression occurred in both conditions, suggesting that the channel-based model does not adequately account for perceived duration of visual events.

Laser Driven Neutron Sources: Characteristics, Applications and Prospects

The basics of laser driven neutron sources, properties and possible applications are discussed. We describe the laser driven nuclear processes which trigger neutron generation, namely, nuclear reactions induced by laser driven ion beam (ion n), thermonuclear fusion by implosion and photo-induced nuclear (gamma n) reactions. Based on their main properties, i.e. point source (< 100 μm) and short durations (< ns), different applications are described, such as radiography, time-resolved spectroscopy and pump-probe experiments. Prospects on the development of laser technology suggest that, as higher intensities and higher repetition rate lasers become available (for example, using DPSSL technology), laser driven methodologies may provide neutron fluxes comparable to that achieved by accelerator driven neutron sources in the near future.

Comparison of Poaceae Pollen Counts Recorded at Sites in Portugal, Spain and the UK

The main aim of this study was to analyse the temporal and spatial variations in grass (Poaceae) pollen counts (2005–2011) recorded in Évora (Portugal), Badajoz (Spain) and Worcester (UK). Weekly average data were examined using nonparametric statistics to compare differences between places. On average, Évora recorded the earliest start dates of the Poaceae pollen seasons and Worcester the latest. The intensity of the Poaceae pollen season varied between sites, with Worcester usually recording the least and Évora the most grass pollen in a season. Mean durations of grass pollen seasons were 77 days in Évora, 78 days in Badajoz and 59 days in Worcester. Overall, longer Poaceae pollen seasons coincided with earlier pollen season start dates. Weekly pollen data, from March to September, from the three pollen-monitoring stations studied were compared. The best fit and most statistically significant correlations were obtained by moving Worcester data backward by 4 weeks (Évora, r = 0.810, p < 0.001) and 5 weeks (Badajoz,r = 0.849, p < 0.001). Weekly data from Worcester therefore followed a similar pattern to that of Badajoz and Évora but at a distance of more than 1,500 km and 4–5 weeks later. The sum of pollen recorded in a season was compared with monthly rainfall between January and May. The strongest positive relationship between season intensity and rainfall was between the annual sum of Poaceae pollen recorded in the season at Badajoz and Évora and total rainfall during January and February. Winter rainfall noticeably affects the intensity of Poaceae pollen seasons in Mediterranean areas, but this was not as important in Worcester.

O uso do smartphone na avaliação do risco de queda associado ao envelhecimento

Introdução: O declínio do equilíbrio, da força dos membros inferiores e o medo de cair são fatores de risco de queda associados ao envelhecimento e a sua avaliação pode ser realizada pelo teste One Leg Standing (OLS), Sit to Stand (STS) e pela Falls Eficacy Scale (FES), respetivamente. As aplicações para smartphone constituem uma alternativa para a avaliação dos fatores de risco de queda no envelhecimento. Objetivo: Analisar a capacidade de uma aplicação para smartphone na avaliação dos testes STS, OLS e FES. Metodologia: Realizou-se um estudo analítico numa amostra de 27 voluntários com idade ≥ 60 anos. Realizaram-se os testes STS, OLS e a FES (versão iconográfica, apresentada no smartphone). Os dados foram recolhidos simultaneamente por um smartphone e pelo Qualisys Motion Capture Systems associado a uma plataforma de forças. Foi utilizado o r de Pearson ou Spearman para analisar as possíveis correlações. Resultados: No STS obteve-se uma correlação muito forte (rp=0.97) no número de repetições de ciclos Sit Stand Sit (SLS) e forte na duração média do SLS (rp=0.85) e das subfases Sit to Stand (rp=0.69) e Stand to Sit (rp=0.778), com p<0.001. As medidas de inclinação do tronco apresentaram correlações fortes, com exceção do ângulo inicial (p≥0.05). No OLS, verificou-se uma correlação moderada entre o deslocamento do centro de pressão peak to peak médio-lateral (rs=0.45; p=0.017) e antero-posterior (rs=0.39; p=0.046), root mean square médio-lateral (rs=0.39; p=0.046) e antero-posterior (rs=0.46; p=0.017) e área do estatocinesiograma (rs=0.45; p=0.018). Na FES obteve-se uma correlação moderada em três categorias: ‘tomar banho/duche’ (rs=0.49; p=0.010), ‘deitar/levantar da cama (rs=0.43; p=0.024) e ‘chegar aos armários’ (rs=0.38; p=0.050). Conclusão: A aplicação para smartphone parece avaliar corretamente os ciclos e a variação da inclinação do tronco no STS, porém parece necessitar de ser reajustada na FES e na velocidade do deslocamento do centro de pressão, no OLS.

A influência da massagem na sensação retardada de desconforto muscular

Introdução: Apesar dos muitos estudos sobre a temática da sensação retardada de desconforto muscular, atualmente, ainda se discute a explicação dos mecanismos subjacentes a esta condição clínica, bem como, a sua prevenção e tratamento. A literatura sugere a massagem como uma das formas de terapia, contudo, os estudos têm mostrado resultados controversos. Objetivo: Verificar se a massagem aplicada 2 horas após um protocolo de exercício excêntrico tem influência na sensação retardada de desconforto muscular, bem como, se o seu efeito varia dependendo do tempo de aplicação. Métodos: 21 participantes (23,62±1,32 anos; 76,95±12,17 kg; 174,71±4,78 cm; 25,25±4,26 Kg/m 2) foram divididos em três grupos. Foi avaliada a dor, força muscular e a perimetria antes, e 2h, 24h, 48h, e 72h após um protocolo de exercício constituído por três séries de dez repetições de contrações excêntricas dos isquiotibiais do membro dominante, com 80% da força máxima, a uma velocidade constante de 60º/s, numa amplitude entre 0º e 80º, utilizando o dinamómetro isocinético Biodex System 4. A massagem foi efetuada 2 horas após o exercício em dois grupos experimentais com durações diferentes, sendo o terceiro grupo de controlo. Para identificar diferenças entre os grupos no momento inicial e na variável diferença entre o momento inicial e os restantes momentos, recorreu-se ao teste de Kruskal-Wallis, seguido de uma análise Post-Hoc através do teste de Dunn com um nível de significância de 0,05. Resultados: Verificou-se que a massagem teve efeito na redução da dor e na perimetria. Relativamente à força não foram encontradas alterações significativas. Conclusão: Os resultados mostraram que a massagem aplicada 2 horas após o exercício excêntrico, independentemente da duração utilizada, teve efeito na redução da dor, mas não na força muscular. Na perimetria apesar de haver alterações, estas não foram consideradas relevantes.