417 research outputs found

    Three Dimensional Fast Exact Euclidean Distance (3D-FEED) Maps

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    In image and video analysis, distance maps are frequently used. They provide the (Euclidean) distance (ED) of background pixels to the nearest object pixel. Recently, the Fast Exact Euclidean Distance (FEED) transformation was launched. In this paper, we present the three dimensional (3D) version of FEED. 3D-FEED is compared with four other methods for a wide range of 3D test images. 3D-FEED proved to be twice as fast as the fastest algorithm available. Moreover, it provides true exact EDs, where other algorithms only approximate the ED. This unique algorithm makes the difference, especially there where time and precision are of importance

    The Enduring Effects of Parental Alcohol, Tobacco, and Drug Use on Child Well-being: A Multilevel Meta-Analysis

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    The effects of psychoactive substance abuse are not limited to the user, but extend to the entire family system, with children of substance abusers being particularly at risk. This meta-analysis attempted to quantify the longitudinal relationship between parental alcohol, tobacco, and drug use and child well-being, investigating variation across a range of substance and well-being indices and other potential moderators. We performed a literature search of peer-reviewed, English language, longitudinal observational studies that reported outcomes for children aged 0 to 18 years. In total, 56 studies, yielding 220 dependent effect sizes, met inclusion criteria. A multilevel random-effects model revealed a statistically significant, small detriment to child well-being for parental substance abuse over time (r = .15). Moderator analyses demonstrated that the effect was more pronounced for parental drug use (r = .25), compared with alcohol use (r = .13), tobacco use (r = .13), and alcohol use disorder (r = .14). Results highlight a need for future studies that better capture the effect of parental psychoactive substance abuse on the full breadth of childhood well-being outcomes and to integrate substance abuse into models that specify the precise conditions under which parental behavior determines child well-being

    Impairment-based assessments for patients with lateral ankle sprain: A systematic review of measurement properties

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    Study design Systematic review. Background and objective The International Ankle Consortium developed a core outcome set for the assessment of impairments in patients with lateral ankle sprain (LAS) without consideration of measurement properties (MP). Therefore, the aim of this study is to investigate MPs of assessments for the evaluation of individuals with a history of LAS. Methods This systematic review of measurement properties follows PRISMA and COSMIN guidelines. Databases Pubmed, CINAHL, Embase, Web of Science, Cochrane Library and SPORTDiscus were searched for eligible studies (last search: July 2022). Studies on MP of specific tests and patient-reported outcome measurements (PROMs) in patients with acute and history of LAS (>4 weeks post injury) were deemed eligible. Results Ten studies of acute LAS and 39 studies of history of LAS patients with a total of 3313 participants met the inclusion criteria. Anterior Drawer Test (ADT) in supine position five days post injury and Reverse Anterolateral Drawer Test are recommended in acute settings in single studies. In the history of LAS patients, Cumberland Ankle Instability Tool (CAIT) (4 studies) as a PROM, Multiple Hop (3 studies) and Star Excursion Balance Tests (SEBT) (3 studies) for dynamic postural balance testing showed good MPs. No studies investigated pain, physical activity level and gait. Only single studies reported on swelling, range of motion, strength, arthrokinematics, and static postural balance. Limited data existed on responsiveness of the tests in both subgroups. Conclusion There was good evidence to support the use of CAIT as PROM, Multiple Hop, and SEBT for dynamic postural balance testing. Insufficient evidence exists in relation to test responsiveness, especially in the acute situation. Future research should assess MPs of assessments of other impairments associated with LAS

    Determining key clinical predictors for chronic ankle instability and return to sports with cost of illness analysis: protocol of a prospective cohort study

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    Introduction: Ankle sprains are common in sports and the general population. Although considered innocuous, a large proportion has residual complaints such as recurrent ankle sprains and develop chronic ankle instability. Although some predicting factors are identified, there is no unequivocality regarding the development of chronic ankle instability, nor about the optimal rehabilitation for an acute ankle sprain. Alongside the biomechanical impairments, ankle sprains are a burden on society due to substantial economic costs. Therefore, we aim to identify key clinical predictors of chronic ankle instability or recovery after acute lateral ankle sprain. Additionally, we aim to determine cost-of-illness of patients who developed chronic ankle instability. Methods and analysis: This prospective cohort study (Clinicaltrials.gov: NCT05637008 - pre-results) aims to recruit adult (18-55 years) patients with an acute lateral ankle sprain who are active in sports. Clinical assessments and patient-reported outcome measures will be used to collect data at 7-14 days, 6 weeks, 12 weeks and 12 months after enrolment in the study. The primary outcome will be chronic ankle instability at 12-month follow-up. Salient outcomes will be analysed by logistic regression to determine association with the development of chronic ankle instability. Participants will fill in a cost diary containing direct and indirect costs related to their injury. Ethics and disseminations: The ethical committee of the Antwerp University Hospital (B3002022000138) has given approval of the protocol and consent forms on 10 October 2022. We perform this study according to the Helsinki Declaration. We will present results at conferences or webinars and publish in peer-reviewed articles.NCT05637008

    Rehabilitation strategies for lateral ankle sprain do not reflect established mechanisms and risk factors for re-injury: A scoping review

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    Introduction: Many athletes suffer recurrent lateral ankle sprain (LAS) on return to sport. Common inciting events for re-injury include changing direction and jumping/landing; this is often mediated by excessive supination at initial contact and/or delay in Peroneus muscle activation. To optimally reduce the risk of recurrent LAS, rehabilitation interventions must reflect the aetiology and mechanisms of these injuries.Aim: Determine if rehabilitation programs in the current literature address common impairments and mechanisms underpinning recurrent LASMaterials and methods: We searched six electronic databases. Inclusion criteria were RCT’s including patients with acute LAS, managed through exercise-based rehabilitation. Each exercise was categorised by the primary impairment(s) addressed (muscle strength, mobility, neuromuscular training, joint positional sense), and by its: direction of movement (uni- vs multiplanar); base of support (single vs double limb); open vs closed chain; and use of a flight phase.Results: The most addressed impairment was sensorimotor function (48%), followed by plantar flexion muscle strength (29%), and sagittal plane mobility (14%). Most exercises were limited to the sagittal plane (48%), with only 30% incorporating multiplanar movements. Two thirds of exercises (118/177) involved closed kinetic chain training, of which, half were undertaken on single leg (59/120). Just 18% of all exercises (33/177) incorporated a flight phase.Conclusion: Rehabilitation strategies for LAS largely comprise simple exercises that do not reflect established mechanisms and risk factors associated with re-injury. Future interventions can be enhanced by incorporating more open chain joint position sense training, multiplanar single limb challenges, and jumping and landing exercises

    Suppression of inhomogeneous broadening in rf spectroscopy of optically trapped atoms

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    We present a novel method for reducing the inhomogeneous frequency broadening in the hyperfine splitting of the ground state of optically trapped atoms. This reduction is achieved by the addition of a weak light field, spatially mode-matched with the trapping field and whose frequency is tuned in-between the two hyperfine levels. We experimentally demonstrate the new scheme with Rb 85 atoms, and report a 50-fold narrowing of the rf spectrum

    Multiple micro-optical atom traps with a spherically aberrated laser beam

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    We report on the loading of atoms contained in a magneto-optic trap into multiple optical traps formed within the focused beam of a CO_{2} laser. We show that under certain circumstances it is possible to create a linear array of dipole traps with well separated maxima. This is achieved by focusing the laser beam through lenses uncorrected for spherical aberration. We demonstrate that the separation between the micro-traps can be varied, a property which may be useful in experiments which require the creation of entanglement between atoms in different micro-traps. We suggest other experiments where an array of these traps could be useful.Comment: 10 pages, 3 figure

    Active optical clock based on four-level quantum system

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    Active optical clock, a new conception of atomic clock, has been proposed recently. In this report, we propose a scheme of active optical clock based on four-level quantum system. The final accuracy and stability of two-level quantum system are limited by second-order Doppler shift of thermal atomic beam. To three-level quantum system, they are mainly limited by light shift of pumping laser field. These limitations can be avoided effectively by applying the scheme proposed here. Rubidium atom four-level quantum system, as a typical example, is discussed in this paper. The population inversion between 6S1/26S_{1/2} and 5P3/25P_{3/2} states can be built up at a time scale of 10−610^{-6}s. With the mechanism of active optical clock, in which the cavity mode linewidth is much wider than that of the laser gain profile, it can output a laser with quantum-limited linewidth narrower than 1 Hz in theory. An experimental configuration is designed to realize this active optical clock.Comment: 5 page
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