416 research outputs found

    A simplex-like search method for bi-objective optimization

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    We describe a new algorithm for bi-objective optimization, similar to the Nelder Mead simplex algorithm, widely used for single objective optimization. For diferentiable bi-objective functions on a continuous search space, internal Pareto optima occur where the two gradient vectors point in opposite directions. So such optima may be located by minimizing the cosine of the angle between these vectors. This requires a complex rather than a simplex, so we term the technique the \cosine seeking complex". An extra beneft of this approach is that a successful search identifes the direction of the effcient curve of Pareto points, expediting further searches. Results are presented for some standard test functions. The method presented is quite complicated and space considerations here preclude complete details. We hope to publish a fuller description in another place

    The Measurement of Wood Cell Parameters Using the Distance Transform

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    In this paper we present a new approach to the quantitative assessment of cell wood boundaries, using image processing techniques based upon the distance transform. It is demonstrated that the method produces the parameters of wall thickness and boundary perimeter using objective measures to estimate these parameters. Further, it is possible, using this technique, to segment the image of a sample of Eucalyptus regnans (mountain ash) into rays, lumens, and cell walls with minimum human intervention

    All two-dimensional expanding Ricci solitons

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    The second author and H. Yin have developed a Ricci flow existence theory that gives a complete Ricci flow starting with a surface equipped with a conformal structure and a nonatomic Radon measure as a conformal factor. This led to the discovery of a large array of new expanding Ricci solitons. In this paper we use the recent uniqueness theory in this context, also developed by the second author and H. Yin, to give a complete classification of all expanding Ricci solitons on surfaces. Along the way, we prove a converse to the existence theory: every complete Ricci flow on a surface over a time interval (0,T)(0,T) admits a t↓0t\downarrow 0 limit within the class of admissible initial data

    Multi-objective engineering shape optimization using differential evolution interfaced to the Nimrod/O tool

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    This paper presents an enhancement of the Nimrod/O optimization tool by interfacing DEMO, an external multiobjective optimization algorithm. DEMO is a variant of differential evolution – an algorithm that has attained much popularity in the research community, and this work represents the first time that true multiobjective optimizations have been performed with Nimrod/O. A modification to the DEMO code enables multiple objectives to be evaluated concurrently. With Nimrod/O’s support for parallelism, this can reduce the wall-clock time significantly for compute intensive objective function evaluations. We describe the usage and implementation of the interface and present two optimizations. The first is a two objective mathematical function in which the Pareto front is successfully found after only 30 generations. The second test case is the three-objective shape optimization of a rib-reinforced wall bracket using the Finite Element software, Code_Aster. The interfacing of the already successful packages of Nimrod/O and DEMO yields a solution that we believe can benefit a wide community, both industrial and academic

    MoveBox: Democratizing MoCap for the Microsoft Rocketbox Avatar Library

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    This paper presents MoveBox an open sourced toolbox for animating motion captured (MoCap) movements onto the Microsoft Rocketbox library of avatars. Motion capture is performed using a single depth sensor, such as Azure Kinect or Windows Kinect V2. Motion capture is performed in real-time using a single depth sensor, such as Azure Kinect or Windows Kinect V2, or extracted from existing RGB videos offline leveraging deep-learning computer vision techniques. Our toolbox enables real-time animation of the user’s avatar by converting the transformations between systems that have different joints and hierarchies. Additional features of the toolbox include recording, playback and looping animations, as well as basic audio lip sync, blinking and resizing of avatars as well as finger and hand animations. Our main contribution is both in the creation of this open source tool as well as the validation on different devices and discussion of MoveBox’s capabilities by end users

    Clinicians' perspectives on supporting individuals with severe anorexia nervosa in specialist eating disorder intensive treatment settings

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    BACKGROUND: Admissions to intensive treatment (i.e., inpatient [IP] and/or day patient [DP]) for individuals with severe anorexia nervosa (AN) are common. Growing literature indicates potential risks and benefits of each intensive treatment approach; however, existing research has focused on patient and carer perspectives of these treatments. Also, there is scant empirical evidence available for guiding the parameters of intensive treatments for AN. We therefore explored clinicians' perspectives and experience of supporting adults with severe AN in intensive settings. METHODS: We conducted twenty one semi-structured interviews with clinicians who deliver intensive treatments (i.e., IP and/or DP) for individuals with severe AN across four specialist Eating Disorder Services in the United Kingdom between May 2020 and June 2021. We asked clinicians about their views and experiences of supporting individuals with severe AN in intensive treatment settings and the challenges and opportunities associated with IP and DP treatment. Data were analysed using reflexive thematic analysis supported by NVivo software. RESULTS: Five broad and interrelated themes were identified: (1) Intensive Support; (2) The Severity of Patients' Illnesses; (3) Hope and Recovery; (4) Which Treatment When; (5) Limited Resources; and (6) Carer Burden. We identified various similarities between the two intensive treatment approaches, including the value of intensive and multidisciplinary support and carer involvement, and the challenge of managing complex and unique needs in resource-limited intensive settings. We also found differences in the relationship of treatment to patients' home environments, the necessity of patient motivation, and the management of risk. CONCLUSIONS: Both intensive treatment settings are valued by clinicians; however, there are unique challenges and opportunities for supporting individuals with severe AN within each. Our findings suggest DP treatment may be used as an alternative to IP treatment for individuals with severe AN. However, clear questions remain over which intensive treatment setting is best suited to which patient when and should be the focus of future research

    Leaning in to Address Sleep Disturbances and Sleep Disorders in Department of Defense and Defense Health Agency

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    Letter to the Editor, Military Medicine, 187, 5/6:155, 202217 USC 105 interim-entered record; under review.The article of record as published may be found at http://dx.doi.org/10.1177/0018720820906050In their article entitled, “Engaging Stakeholders to Optimize Sleep Disorders Management in the U.S. Military: A Qualitative Analysis,” Abdelwadoud and colleagues conducted focus groups of service members, primary care managers (PCMs), and administrative stakeholders about their perceptions, experiences, roles in sleep management, stated education needs, and management of sleep disorders.1 The qualitative methods are rigorous, and the findings reinforce and nuance prior results, especially regarding key requirements from PCMs. We feel compelled, however, to further nuance the authors’ conclusion that “current military sleep management practices are neither satisfactory nor maximally effective” and offer specific examples of actions taken by the Department of Defense (DoD) and Defense Health Agency (DHA) in recognition of the significance of optimal sleep in combat readiness and overall health of service members. We offer here a succinct list of concrete efforts to support and implement substantial clinical, operational, research, or educational efforts by the DoD or DHA to improve sleep in service members and associated clinical challenges in this unique population.Identified in text as U.S. Government work

    Ballistic protective properties of material representative of English civil war buff-coats and clothing

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    One type of clothing system used in the English Civil War, more common amongst cavalrymen than infantrymen, was the linen shirt, wool waistcoat and buff-coat. Ballistic testing was conducted to estimate the velocity at which 50% of 12-bore lead spherical projectiles (V50) would be expected to perforate this clothing system when mounted on gelatine (a tissue simulant used in wound ballistic studies). An estimated six-shot V50 for the clothing system was calculated as 102 m/s. The distance at which the projectile would have decelerated from the muzzle of the weapon to this velocity in free flight was triple the recognised effective range of weapons of the era suggesting that the clothing system would provide limited protection for the wearer. The estimated V50 was also compared with recorded bounce-and-roll data; this suggested that the clothing system could provide some protection to the wearer from ricochets. Finally, potential wounding behind the clothing system was investigated; the results compared favourably with seventeenth century medical writings

    The relationships between faecal egg counts and gut microbial composition in UK Thoroughbreds infected by cyathostomins

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    A growing body of evidence, particularly in humans and rodents, supports the existence of a complex network of interactions occurring between gastrointestinal (GI) helminth parasites and the gut commensal bacteria, with substantial effects on both host immunity and metabolic potential. However, little is known of the fundamental biology of such interactions in other animal species. Nonetheless, given the considerable economic losses associated with GI parasites, particularly in livestock and equines, as well as the global threat of emerging anthelmintic resistance, further explorations of the complexities of host-helminth-microbiota interactions in these species are needed. This study characterises the composition of the equine bacterial commensal flora associated with the presence, in faecal samples, of low (Clow) - and high (Chigh) numbers of eggs of an important group of equine GI parasites (i.e. the cyathostomins), prior to and following anthelmintic treatment. High-throughput sequencing of microbial 16S rRNA amplicons and associated bioinformatics and statistical analyses of sequence data revealed strong clustering according to faecal egg counts (P = 0.003). A trend towards increased populations of Methanomicrobia (class) and Dehalobacterium (genus) was observed in Clow in comparison with Chigh. Anthelmintic treatment in Chigh was associated with a significant reduction of the bacterial phylum TM7 14 days post-ivermectin administration, as well as a transient expansion of Adlercreuzia spp. at 2 days post-treatment. This study provides a first known insight into the discovery of the intimate mechanisms governing host-parasite-microbiota interactions in equids, and sets a basis for the development of novel, biology-based intervention strategies against equine GI helminths based on manipulation of the commensal gut flora

    Exploring perceptions of consanguineous unions with women from an East London community: analysis of discussion groups

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    Consanguineous unions are relationships between blood relatives. This study explores the perceptions of consanguineous unions and risk of childhood disability and illness through the reported views and experiences of women in an ethnically diverse London community. This qualitative study utilised group discussions to elicit women's views and experiences. Field notes were recorded by independent note-takers in four group discussions. Field notes were coded manually and independently by two researchers who identified common themes for thematic analysis. Thirty-six women attended, of whom 20 identified as Asian Pakistani. Identified themes included variation in participants' views of consanguineous unions and associated health risks, the value of informed decisions and preferences for information distribution. Although participants had diverse opinions and experiences, they considered risk awareness to be vital for encouraging informed decisions in younger generations. This study highlights the importance of involving the community in efforts to increase awareness around consanguineous unions and genetic risk, emphasising the need for enabling educated choices and the value of co-developing educational efforts with the community
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