1,473 research outputs found

    Robustness of Planar Fourier Capture Arrays to Colour Changes and Lost Pixels

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    Planar Fourier capture arrays (PFCAs) are optical sensors built entirely in standard microchip manufacturing flows. PFCAs are composed of ensembles of angle sensitive pixels (ASPs) that each report a single coefficient of the Fourier transform of the far-away scene. Here we characterize the performance of PFCAs under the following three non-optimal conditions. First, we show that PFCAs can operate while sensing light of a wavelength other than the design point. Second, if only a randomly-selected subset of 10% of the ASPs are functional, we can nonetheless reconstruct the entire far-away scene using compressed sensing. Third, if the wavelength of the imaged light is unknown, it can be inferred by demanding self-consistency of the outputs.Comment: 15 pages including cover page, 12 figures, associated with the 9th International Conference on Position Sensitive Detector

    The early identification of risk factors on the pathway to school dropout in the SIODO study:A sequential mixed-methods study

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    BACKGROUND: School dropout is a persisting problem with major socioeconomic consequences. Although poor health probably contributes to pathways leading to school dropout and health is likely negatively affected by dropout, these issues are relatively absent on the public health agenda. This emphasises the importance of integrative research aimed at identifying children at risk for school dropout at an early stage, discovering how socioeconomic status and gender affect health-related pathways that lead to dropout and developing a prevention tool that can be used in public health services for youth. METHODS/DESIGN: The SIODO study is a sequential mixed-methods study. A caseā€“control study will be conducted among 18 to 24 year olds in the south of the Netherlands (n = 580). Data are currently being collected from compulsory education departments at municipalities (dropout data), regional public health services (developmental data from birth onwards) and an additional questionnaire has been sent to participants (e.g. personality data). Advanced analyses, including cluster and factor analyses, will be used to identify children at risk at an early stage. Using the quantitative data, we have planned individual interviews with participants and focus groups with important stakeholders such as parents, teachers and public health professionals. A thematic content analysis will be used to analyse the qualitative data. DISCUSSION: The SIODO study will use a life-course perspective, the ICF-CY model to group the determinants and a mixed-methods design. In this respect, the SIODO study is innovative because it both broadens and deepens the study of health-related determinants of school dropout. It examines how these determinants contribute to socioeconomic and gender differences in health and contributes to the development of a tool that can be used in public health practice to tackle the problem of school dropout at its roots

    Anti-inflammatory and combined antiinflammatory/ analgesic medication in the early management of iliotibial band friction syndrome A clinical trial

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    Forty-three athletes presenting with unilateral iliotibial band friction syndrome (ITBFS) were randomly divided into three groups for the first 7 days of treatment (placebo-controlled, double-blind): 1 - placebo (N = 13); 2 - anti-inflammatory medication (N = 14) (Voharen; Geigy); and 3 - analgesicl anti-inflammatory combined medication (N =. 16) (Myprodol; Rio Ethicals). All subjects rested from day 0 to day 7 and all groups received the same physiotherapy outpatient treatment programme from day 3 to day 7. On days 0, 3 and 7 the subjects performed a functional treadmill running test (maximum 30 minutes) during which they reported pain (scale 0-10; 0 = no pain, 10 = unbearable pain) each minute. Total running distance, total running time and the area under the pain v. time curve was calculated. Daily 24-hour recall pain scores were also recorded. The 24-hour recall pain scores decreased significantly for all the groups over the treatment period. This method of assessing efficacy of treatment therefore failed to show differences between groups. In contrast, during the running test only group 3 improved their total running time and distance from day 0 to day 7, whereas in all the groups the area under the pain v. time curve decreased from day 0 to day 7. All the other groups improved total running time and running distance from day 3 to day 7. All three treatment modalities are effective in the early. treatment of ITBFS but physiotherapy in combination with analgesicl anti-inflammatory medication is superior. A functional running test, which is more sensitive than conventional pain-recallĀ· methods in assessing efficacy of treatment in this type of clinical trial, is described

    Artificial intelligence for automated Carnegie staging of the human embryo in three-dimensional ultrasound:the Rotterdam periconception cohort

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    Since automatic Carnegie staging using AI is real-time and does not require a VR set-up adoption in clinical practice becomes feasible. In future work, we aim to enhance interpretability by analysing the specific morphological aspects in ultrasound scans utilised by the algorithm to assign the Carnegie stage. Understanding the morphological aspects linked to the Carnegie stage by the algorithm might lead to more in-depth insight into the patterns of normal and abnormal morphological development across pregnancie

    Mode locking of vortex matter driven through mesoscopic channels

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    We investigated the driven dynamics of vortices confined to mesoscopic flow channels by means of a dc-rf interference technique. The observed mode-locking steps in the IVIV-curves provide detailed information on how the number of rows and lattice structure in the channel change with magnetic field. Minima in flow stress occur when an integer number of rows is moving coherently, while maxima appear when incoherent motion of mixed nn and nĀ±1n\pm 1 row configurations is predominant. Simulations show that the enhanced pinning at mismatch originates from quasi-static fault zones with misoriented edge dislocations induced by disorder in the channel edges.Comment: some minor changes were made, 4 pages, 4 figures, accepted for publication in Phys. Rev. Let

    Effect of Pulsed or Continuous Delivery of Salt on Sensory Perception Over Short Time Intervals

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    Salt in the human diet is a major risk factor for hypertension and many countries have set targets to reduce salt consumption. Technological solutions are being sought to lower the salt content of processed foods without altering their taste. In this study, the approach was to deliver salt solutions in pulses of different concentrations to determine whether a pulsed delivery profile affected sensory perception of salt. Nine different salt profiles were delivered by a Dynataste device and a trained panel assessed their saltiness using timeā€“intensity and single-score sensory techniques. The profile duration (15 s) was designed to match eating conditions and the effects of intensity and duration of the pulses on sensory perception were investigated. Sensory results from the profiles delivered in either water or in a bouillon base were not statistically different. Maximum perceived salt intensities and the area under the timeā€“ intensity curves correlated well with the overall perceived saltiness intensity despite the stimulus being delivered as several pulses. The overall saltiness scores for profiles delivering the same overall amount of sodium were statistically not different from one another suggesting that, in this system, pulsed delivery did not enhance salt perception but the overall amount of salt delivered in each profile did affect sensory perception

    Periconceptional maternal supplement intake and human embryonic growth, development, and birth outcomes:The Rotterdam Periconception Cohort

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    STUDY QUESTION: Is periconceptional multiple-micronutrient supplement (MMS) use including folic acid (FA) compared to FA use only associated with increased embryonic growth, development, and birth weight in a high-risk population? SUMMARY ANSWER: Women with MMS intake show no significant differences in first-trimester morphological embryo development, but increased first-trimester embryonic growth trajectories and fewer neonates born small for gestational age (SGA), less than the 3rd percentile (&lt;p3), compared to women using only FA. WHAT IS KNOWN ALREADY: Periconceptional maternal FA intake in the general population is associated with increased embryonic and fetal growth, and reduced risks of neural tube defects, other congenital malformations, low birth weight, and neonates born SGA. STUDY DESIGN, SIZE, DURATION: A prospective tertiary hospital-based cohort study (the Rotterdam Periconceptional Cohort) was conducted from January 2010 to December 2020. PARTICIPANTS/MATERIALS, SETTING, METHODS: We included 1076 women from the Rotterdam Periconceptional Cohort, before 10 weeks of pregnancy with follow-up until delivery. Embryonic growth was assessed by measurement of crown-rump length (CRL) and embryonic volume (EV), and embryonic morphology was described by Carnegie stages using longitudinal three-dimensional ultrasound scans and virtual reality techniques. Birth outcomes were extracted from medical records. General characteristics and supplement use were extracted from research questionnaires. MAIN RESULTS AND THE ROLE OF CHANCE: This study showed increased embryonic growth trajectories (adjusted models, CRL: Ī² = 0.052, 95% CI 0.012-0.090, EV: Ī² = 0.022, 95% CI 0.002-0.042) in women using MMS compared to those using only FA. Moreover, a 45% reduced risk of a neonate-born SGA (&lt;p3) was shown in women using MMS compared to FA users (adjusted OR = 0.546, 95% CI 0.308, 0.969). Embryonic morphological development (Carnegie stages) and the occurrence of miscarriages did not differ between women using MMS or solely FA. LIMITATIONS, REASONS FOR CAUTION: Following the heterogeneity of the composition and dose of MMS preparations, it is unclear which specific micronutrient, combination, or dose explains the increased embryonic growth trajectory and reduction in risk for SGA. This also hampers the possibility of differentiating between the effects of FA alone or as a component of MMS. WIDER IMPLICATIONS OF THE FINDINGS: Our findings emphasize the importance of periconceptional maternal MMS use as a potential preventative intervention against reduced embryonic growth and neonates born SGA. Therefore, we recommend the periconceptional use of MMS in women at risk of inadequate micronutrient intake. However, awareness of potentially harmful side effects of high doses and combinations of micronutrients is essential, therefore the optimal composition and dose need to be investigated, and careful surveillance is recommended.</p

    Nonlocal Conductivity in the Vortex-Liquid Regime of a Two-Dimensional Superconductor

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    We have simulated the time-dependent Ginzburg-Landau equation with thermal fluctuations, to study the nonlocal dc conductivity of a superconducting film. Having examined points in the phase diagram at a wide range of temperatures and fields below the mean-field upper critical field, we find a portion of the vortex-liquid regime in which the nonlocal ohmic conductivity in real space is negative over a distance several times the spacing between vortices. The effect is suppressed when driven beyond linear response. Earlier work had predicted the existence of such a regime, due to the high viscosity of a strongly-correlated vortex liquid. This behavior is clearly distinguishable from the monotonic spatial fall-off of the conductivity in the higher temperature or field regimes approaching the normal state. The possibilities for experimental study of the nonlocal transport properties are discussed.Comment: 18 pages, revtex, 6 postscript figure
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