1,024 research outputs found

    Early experience, binocular competition, and the sculpting of relay cell morphology in the cat lateral geniculate nucleus

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    Perturbations of early visual experience imposed by either monocular deprivation (MD) or artificially induced strabismus (squint) affect the morphological development of cells in the lateral geniculate nucleus (LGN) of cats. These morphological anomalies are thought to arise from competitive mechanisms which control many features of LGN cell development. Competition between the axon terminals of LGN cells innervated by the right and left eyes for establishing and maintaining synaptic contacts with cells in the visual cortex (i.e., binocular competition) is known to be a very important mechanism for controlling the development of LGN cells. Much of our present understanding regarding the importance of binocular competition is based on the effects of MD and squint on LGN somata. The objective of the present study was to further explore the role of binocular competition in the somatic development of LGN cells and extend these observations to determine the role of binocular competition in the dendritic development of LGN cells. Binocular competition was eliminated in some of the animals reared with either MD or squint by concomitant sagittal transection of the optic chiasm (OX), performed on either postnatal day 27 or 28

    Robust Fundamental Matrix Determination without Correspondences

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    Estimation of the fundamental matrix is key to many problems in computer vision as it allows recovery of the epipolar geometry between camera images of the same scene. The estimation from feature correspondences has been widely addressed in the literature, particularly in the presence of outliers. In this paper, we propose a new robust method to estimate the fundamental matrix from two sets of features without any correspondence information. The method operates in the frequency domain and the underlying estimation process considers all features simultaneously, thus yielding a high robustness with respect to noise and outliers. In addition, we show that the method is well-suited to widely separate viewpoints

    School leaders reflections on their school's engagement in a program to foster health literacy development

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    Many health attitudes and behaviors formed during childhood are sustained through to adulthood, thereforechildhood is a critical time to develop health literacy. Primary schools provide an ideal environment to equipchildren with lifelong health skills, understanding and knowledge. Through semi-structured interviews, this studygathered primary school leaders’ reflections on the implementation of a program (HealthLit4Kids) designed tofoster health literacy development in their schools. The aim of this study was to determine how school leadersexperienced the HealthLit4Kids intervention. The results showed that leaders perceived the program had a positive effect on health literacy knowledge and understanding within the school community, as well as improvedhealth behaviors. School leaders’ statements indicated that key barriers such as parental engagement and anovercrowded curriculum would need to be navigated to ensure successful program sustainability

    The development of a protocol for diagnosing hand dermatitis from photographic images

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    Background: A hand photography protocol was needed to ascertain the presence and severity of dermatitis in a trial testing the effectiveness of a behaviour change intervention to prevent hand dermatitis in nurses. Methods: We developed the protocol in three stages: (i) established a procedure for collecting hand photographs; (ii) conducted a stepwise validation process to agree rules for diagnosing and determining severity of hand dermatitis and; (iii) trained a research nurse to screen out ‘clear’ cases. Results: We developed and trained fieldworkers (n=97) in a procedure for collecting hand photographs. Study dermatologists established interpretation rules to diagnose and determine the severity of dermatitis from photographs. Prior to the establishment of the rules, inter-observer agreement between the two dermatologists on the presence or absence of hand dermatitis was moderate (kappa 0.5). At the final stage of the validation process, the dermatologists agreed on 88% cases from independent assessments, with consensus reached for the remaining 12% following joint deliberation. Following training, a subgroup analysis of 250 cases screened by the nurse and characterised as ‘clear’ found two (0.8%) ‘positive’ cases were missed. Conclusion: We have developed a hand photography protocol, which may be used in other studies or in hand dermatitis health surveillance programmes

    Bridging the gap between evidence-based innovation and national health-sector reform in Ghana

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    Although experimental trials often identify optimal strategies for improving community health, transferring operational innovation from well-funded research programs to resource-constrained settings often languishes. Because research initiatives are based in institutions equipped with unique resources and staff capabilities, results are often dismissed by decisionmakers as irrelevant to large-scale operations and national health policy. This article describes an initiative undertaken in Nkwanta District, Ghana, focusing on this problem. The Nkwanta District initiative is a critical link between the experimental study conducted in Navrongo, Ghana, and a national effort to scale up the innovations developed in that study. A 2002 Nkwanta district-level survey provides the basis for assessing the likelihood that the Navrongo model is replicable elsewhere in Ghana. The effect of community-based health planning and services exposure on family planning and safe-motherhood indicators supports the hypothesis that the Navrongo model is transferable to impoverished rural settings elsewhere. This finding confirms the need for strategies to bridge the gap between Navrongo evidence-based innovation and national health-sector reform

    ParaVR: A Virtual Reality Training Simulator for Paramedic Skills maintenance

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Paramedic Practice, copyright © MA Healthcare, after peer review and technical editing by the publisher. To access the final edited and published work see https://www.paramedicpractice.com/features/article/paravr-a-virtual-reality-training-simulator-for-paramedic-skills-maintenance.Background, Virtual Reality (VR) technology is emerging as a powerful educational tool which is used in medical training and has potential benefits for paramedic practice education. Aim The aim of this paper is to report development of ParaVR, which utilises VR to address skills maintenance for paramedics. Methods Computer scientists at the University of Chester and the Welsh Ambulance Services NHS Trust (WAST) developed ParaVR in four stages: 1. Identifying requirements and specifications 2. Alpha version development, 3. Beta version development 4. Management: Development of software, further funding and commercialisation. Results Needle Cricothyrotomy and Needle Thoracostomy emerged as candidates for the prototype ParaVR. The Oculus Rift head mounted display (HMD) combined with Novint Falcon haptic device was used, and a virtual environment crafted using 3D modelling software, ported (a computing term meaning transfer (software) from one system or machine to another) onto Oculus Go and Google cardboard VR platform. Conclusion VR is an emerging educational tool with the potential to enhance paramedic skills development and maintenance. The ParaVR program is the first step in our development, testing, and scaling up of this technology

    The Astropy Problem

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    The Astropy Project (http://astropy.org) is, in its own words, "a community effort to develop a single core package for Astronomy in Python and foster interoperability between Python astronomy packages." For five years this project has been managed, written, and operated as a grassroots, self-organized, almost entirely volunteer effort while the software is used by the majority of the astronomical community. Despite this, the project has always been and remains to this day effectively unfunded. Further, contributors receive little or no formal recognition for creating and supporting what is now critical software. This paper explores the problem in detail, outlines possible solutions to correct this, and presents a few suggestions on how to address the sustainability of general purpose astronomical software

    Compared to placebo, long-term antibiotics resolve otitis media with effusion (OME) and prevent acute otitis media with perforation (AOMwiP) in a high-risk population: A randomized controlled trial

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    © 2008 Leach et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background : For children at high risk of chronic suppurative otitis media (CSOM), strategies to prevent acute otitis media with perforation (AOMwiP) may reduce progression to CSOM. Methods : In a double blind study in northern Australia, 103 Aboriginal infants with first detection of OME were randomised to receive either amoxicillin (50 mg/kg/d BD) or placebo for 24 weeks, or until bilateral aerated middle ears were diagnosed at two successive monthly examinations (success). Standardised clinical assessments and international standards for microbiology were used. Results : Five of 52 infants in the amoxicillin group and none of 51 infants in the placebo group achieved success at the end of therapy (Risk Difference = 9.6% [95% confidence interval 1.6,17.6]). Amoxicillin significantly reduced the proportion of children with i) perforation at the end of therapy (27% to 12% RD = -16% [-31,-1]), ii) recurrent perforation during therapy (18% to 4% RD = -14% [-25,-2]), and iii) reduced the proportion of examinations with a diagnosis of perforation during therapy (20% to 8% adjusted risk ratio 0.36 [0.15,0.83] p = 0.017). During therapy, the proportion of examinations with penicillin non-susceptible (MIC > 0.1 microg/ml) pneumococci was not significantly different between the amoxicillin group (34%) and the placebo group (40%). Beta-lactamase positive non-capsular H. influenzae (NCHi) were uncommon during therapy but more frequent in the amoxicillin group (10%) than placebo (5%). Conclusion : Aboriginal infants receiving continuous amoxicillin had more normal ears, fewer perforations, and less pneumococcal carriage. There was no statistically significant increase in resistant pneumococci or NCHi in amoxicillin children compared to placebo children who received regular paediatric care and antibiotic treatment for symptomatic illnesses

    ActEarly: a City Collaboratory approach to early promotion of good health and wellbeing.

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    Economic, physical, built, cultural, learning, social and service environments have a profound effect on lifelong health. However, policy thinking about health research is dominated by the 'biomedical model' which promotes medicalisation and an emphasis on diagnosis and treatment at the expense of prevention. Prevention research has tended to focus on 'downstream' interventions that rely on individual behaviour change, frequently increasing inequalities. Preventive strategies often focus on isolated leverage points and are scattered across different settings. This paper describes a major new prevention research programme that aims to create City Collaboratory testbeds to support the identification, implementation and evaluation of upstream interventions within a whole system city setting. Prevention of physical and mental ill-health will come from the cumulative effect of multiple system-wide interventions. Rather than scatter these interventions across many settings and evaluate single outcomes, we will test their collective impact across multiple outcomes with the goal of achieving a tipping point for better health. Our focus is on early life (ActEarly) in recognition of childhood and adolescence being such critical periods for influencing lifelong health and wellbeing

    Winter Rye Cover Crop Biomass Production, Degradation, and Nitrogen Recycling

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    Winter rye (Secale cereale L.) cover crop (RCC) use in corn (Zea mays L.) and soybean [Glycine max. (L.) Merr.] production can alter N dynamics compared to no RCC. The objectives of this study were to evaluate RCC biomass production (BP) and subsequent RCC degradation (BD) and N recycling in a no-till corn–soybean (CS) rotation. Aboveground RCC was sampled at spring termination for biomass dry matter (DM), C, and N. To evaluate BD and remaining C and N, RCC biomass was put into nylon mesh bags, placed on the soil surface, and collected multiple times over 105 d. Treatments included rye cover crop following soybean (RCC-FS) and corn (RCC-FC), and prior-year N applied to corn. Overall, the RCC BP and N was low due to low soil profile NO3–N. Across sites and years, the greatest BP was with RCC-FC that received 225 kg N ha–1 (1280 kg DM ha–1), with similar N uptake as with RCC-FS (27 kg N ha–1). The RCC biomass and N remaining decreased over time following an exponential decay. An average 62% biomass with RCC-FS and RCC-FC degraded after 105 d; however, N recycled was greater with RCC-FS than RCC-FC [22 (80%) vs. 14 (64%) kg N ha–1, respectively], and was influenced by the RCC C/N ratio. The RCC did not recycle an agronomically meaningful amount of N, which limited N that could potentially be supplied to corn. Rye cover crops can conserve soil N, and with improved management and growth, recycling of crop-available N should increase
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