60419 research outputs found
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Complementary Discriminative Correlation Filters Based on Collaborative Representation for Visual Object Tracking
No full textIn recent years, discriminative correlation filter
(DCF) based algorithms have significantly advanced the state of the art in visual object tracking. The key to the success of DCF is an efficient discriminative regression model trained
with powerful multi-cue features, including both hand-crafted and deep neural network features. However, the tracking performance is hindered by their inability to respond adequately to abrupt target appearance variations. This issue is posed by the limited representation capability of fixed image features. In this work, we set out to rectify this shortcoming by proposing a complementary representation of a visual content. Specifically, we propose the use of a collaborative representation between
successive frames to extract the dynamic appearance information from a target with rapid appearance changes, which results in suppressing the undesirable impact of the background. The resulting collaborative representation coefficients are combined
with the original feature maps using a spatially regularised DCF framework for performance boosting. The experimental results on several benchmarking datasets demonstrate the effectiveness and robustness of the proposed method, as compared with a
number of state-of-the-art tracking algorithms
Measurements and modelling of particulate matter building ingress during a severe dust storm event
No full textDust storms are a common phenomenon that occurs in many dry and arid areas, demonstrates very high levels of particulate matter (PM), can spread significantly further than its origin, affects both outdoor and indoor air quality, and can cause serious health problems although it is a low frequency event. Focus of this study is the prediction of PM (PM₂.₅ and PM₁₀) infiltration at typical commercial and office building environments during severe dust storms. Therefore, a two-month field campaign was conducted to capture such an event in Doha, Qatar, and a modelling methodology is proposed based on the one-way coupling of a multi-zone and a computational fluid dynamics software. The predicted levels are in fair agreement with the measurements for both the dust storm and typical days, attributed to the accurate estimation of the external wind pressure and representation of the building envelope. The agreement further improves when the efficiency of the ventilation filters is estimated, from the measuremetns, rather than being extracted from specification sheets. Finally, predictions are found to conform with physical reality and to offer useful insights into PM building infiltration during dust storm events when cross examined with measurements
A mechanism for learning with sleep spindles
No full textSpindles are ubiquitous oscillations during non-rapid eye movement (NREM) sleep. A growing body of evidence points to a possible link with learning and memory, and the underlying mechanisms are now starting to be unveiled. Specifically, spindles are associated with increased dendritic activity and high intracellular calcium levels, a situation favourable to plasticity, as well as with control of spiking output by feed-forward inhibition. During spindles, thalamocortical networks become unresponsive to inputs, thus potentially preventing interference between memory-related internal information processing and extrinsic signals. At the system level, spindles are co-modulated with other major NREM oscillations, including hippocampal sharp wave-ripples (SWRs) and neocortical slow waves, both previously shown to be associated with learning and memory. The sequential occurrence of reactivation at the time of SWRs followed by neuronal plasticity-promoting spindles is a possible mechanism to explain NREM sleep-dependent consolidation of memories
A qualitative analysis of psychosocial needs and support impacts in families affected by young sudden cardiac death: The role of community and peer support
No full textBackground
Young sudden cardiac death (YSCD), often occurring in previously healthy individuals, is a tragic event with devastating impact on affected families, who are at heightened risk of posttraumatic stress and prolonged grief and may themselves be at risk of YSCD. Previous research suggests that surviving family members’ psychosocial support needs are often unmet.
Purpose
This study sought to identify how YSCD-affected families experience dedicated community and peer support in light of their psychosocial support needs.
Methods
The study used a qualitative design, employing a thematic analysis of focus group and interview data. Three focus groups and five individual interviews were conducted with affected family members (N = 19). The sample was drawn from a UK-based charity, Cardiac Risk in the Young. Audio-recordings of the focus groups and interviews were transcribed and subjected to thematic analysis.
Results
Three super-ordinate themes were identified: 1. YSCD community support as offering a place of safety, 2. YSCD community support as fostering sense-making, 3. YSCD community support as facilitating finding new meaning.
Conclusions
YSCD-affected families can benefit from access to dedicated community and peer support that offers a safe environment, provides affiliation, understanding and normalisation and enables sense-making and the rebuilding of a sense of self. Dedicated community support can facilitate meaningful re-engagement with life through helping prevent YSCD and through memorialisation and legacy-building to maintain a continuing bond with the deceased. Clinicians need to be aware of the need to incorporate available community and peer support into patient pathways.</p
Active flow control on a square-back road vehicle
No full textAn experimental investigation focused on the manipulation of the wake generated by a square back car model is presented. Four continuously-blowing rectangular slot jets were mounted on the rear face of a 1:10 commercial van model. Load cell measurements evidence drag reduction for different forcing configurations, reaching a maximum of 12% for lateral and bottom jets blowing. The spectral analysis of the pressure fluctuations evidence, for all forced cases, an energy attenuation with respect to the natural case, especially close to the shedding frequency. An energy budget highlighted the most efficient forcing configurations accounting for both the drag reduction and the power required to feed the blowing system. Two main configurations are considered: the maximum drag reduction and the best compromise, yielding 5% drag reduction and a convenient energy balance. Particle Image Velocimetry (pPIV) and stereoscopic PIV (sPIV) experiments were performed allowing the three-dimensional reconstruction of the wake in the three considered configurations. Consistently with static and fluctuating pressure measurements, sPIV results reveal a dramatic change in the wake structure when the jets blow in the maximum drag reduction configuration. Conversely, the best compromise configuration reveals a wake structure similar to the natural one
The EAHAD blood coagulation factor VII variant database
No full textHereditary blood coagulation factor VII (FVII) deficiency is a rare autosomal recessive bleeding disorder resulting from variants in the gene encoding FVII (F7). Integration of genetic variation with functional consequences on protein function is essential for the interpretation of the pathogenicity of novel variants. Here, we describe the integration of previous locus‐specific databases for F7 into a single curated database with enhanced features. The database provides access to in silico analyses that may be useful in the prediction of variant pathogenicity as well as cross‐species sequence alignments, structural information, and functional and clinical severity described for each variant, where appropriate. The variant data is shared with the F7 Leiden Open Variation Database. The updated database now includes 221 unique variants, representing gene variants identified in 728 individuals. Single nucleotide variants are the most common type (88%) with missense representing 74% of these variants. A number of variants are found with relatively high minor allele frequencies that are not pathogenic but contribute significantly to the likely pathogenicity of coinherited variants due to their effect on FVII plasma levels. This comprehensive collection of curated information significantly aids the assessment of pathogenicity
FATIMA — FAst TIMing Array for DESPEC at FAIR
No full textThe components, working principle and characteristics of FATIMA (FAst TIMing Array), a fast-timing detector system for DESPEC at FAIR, are described. The core system includes 36 LaBr3(Ce) scintillator detectors, a mounting frame for the DESPEC station and a VME-based fast-timing data acquisition system. The current electronic timing circuit is based on V812 constant fraction discriminators and V1290 time-to-digital converters. Gamma-ray energies are measured using V1751 digitisers. Characteristics of the core FATIMA system including efficiency, energy, and coincidence resolving time, as well as limitations, are discussed on the basis of test measurements performed in the S4 cave at GSI, Germany. The coincidence γ-γ time resolution for the prompt 60Co cascade is determined to be ~320 ps full width at half maximum. The total full energy peak efficiency at 1 MeV for the 36 detector array in the DESPEC setup is 2.9%. The energy-dependent prompt response centroid curve with the current CFD/TDC combination is shown to be smooth; the centroid shift method can be applied for the measurement of half-lives below 200 ps. An overview of applications of the FATIMA detectors as an ancilliary system in combination with other detector arrays during recent years is given. Data on the operation of the detectors in the presence of magnetic fields are presented
Cultivating Open Government Data Platform Ecosystems through Governance: Lessons from Buenos Aires, Mexico City and Montevideo
No full textOpen government data (OGD) initiatives are an emergent platform research topic. There is little under-standing how these platforms are governed for the innovation of services using open data, where the cultivation of an installed base of heterogeneous service innovators can lead to increased usage of OGD. In this paper, we draw on established literature from digital platforms research to investigate how service innovation is cultivated in open government data contexts. We employ a comparative case study of open government data platforms in three leading Latin American cities and draw upon the concept of bound-ary resources taken from platform theory. Our research generates two key contributions. First, we pro-pose a theoretical model, which explains how an OGD platform owner is able to govern the demand and the supply side of its platform to facilitate the cultivation of a platform ecosystem. Second, we develop contributions to practice in terms of a set of recommendations for governments in emerging countries concerning how to establish and manage a vibrant OGD platform ecosystem
Interventions for caregivers of children with food allergy: a systematic review
No full textBackground
Studies have identified that food allergy (FA) in children is related to poorer caregiver quality of life (QoL). However, it is unclear which interventions are most effective at improving outcomes for caregivers of children with FA. This review aimed to identify and determine the efficacy, acceptability and quality of interventions for caregivers of children with FA.
Methods
A systematic search of four databases was conducted to identify studies evaluating any intervention that targeted wellbeing and support in caregivers of children with FA. Studies were not excluded based on design and were rated for quality using the mixed method appraisal tool (MMAT) and the Cochrane risk of bias tool for randomised controlled trials (RCTs).
Results
Fifteen studies met inclusion; eight studies used a pre‐test post‐test design, four used a post‐test design, two were RCTs and one a case‐control design. Seven studies were educational interventions, five were psychological, and three involved peer/professional support. All interventions had high participant acceptability; some evidence for cognitive behavioural interventions in supporting mothers was observed. Educational interventions tended to be associated with improvements in FA knowledge. With exception of three studies, most studies were assessed as poor or moderate in terms of quality.
Conclusion
There is a paucity of high‐quality research evaluating interventions to improve outcomes in parents of children with FA. Limited evidence suggest that cognitive behavioural interventions could benefit some mothers, but this has not been tested in other populations. Future research should use methodologically sound designs with validated outcome measures.</p
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