351 research outputs found

    Aneuploidy among androgenic progeny of hexaploid triticale (XTriticosecale Wittmack).

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    Doubled haploids are an established tool in plant breeding and research. Of several methods for their production, androgenesis is technically simple and can efficiently produce substantial numbers of lines. It is well suited to such crops as hexaploid triticale. Owing to meiotic irregularities of triticale hybrids, aneuploidy may affect the efficiency of androgenesis more severely than in meiotically stable crops. This study addresses the issue of aneuploidy among androgenic regenerants of triticale. Plant morphology, seed set and seed quality were better predictors of aneuploidy, as determined cytologically, than flow cytometry. Most aneuploids were hypoploids and these included nullisomics, telosomics, and translocation lines; among 42 chromosome plants were nulli-tetrasomics. Rye chromosomes involved in aneuploidy greatly outnumbered wheat chromosomes; in C(0) rye chromosomes 2R and 5R were most frequently involved. While the frequency of nullisomy 2R was fairly constant in most cross combinations, nullisomy 5R was more frequent in the most recalcitrant combination, and its frequency increased with time spent in culture with up to 70% of green plants recovered late being nullisomic 5R. Given that 5R was not involved in meiotic aberrations with an above-average frequency, it is possible that its absence promotes androgenesis or green plant regeneration. Overall, aneuploidy among tested combinations reduced the average efficiency of double haploid production by 35% and by 69% in one recalcitrant combination, seriously reducing the yield of useful lines

    Preliminary flight prototype waste collection subsystem

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    The zero gravity test program demonstrated the feasibility and practicability of collecting urine from both male and female crew members in a zero gravity environment in an earthlike manner not requiring any manual handling of urine containers. In addition, the testing demonstrated that a seat which is comfortable in both regimes of operation could be designed for use on the ground and in zero-gravity. Further, the tests showed that the vortex liquid/air separator is an effective liquid/air separation method in zero gravity. Visual observations indicate essentially zero liquid carry over. The system also demonstrated its ability to handle post elimination wipes without difficulty. The designs utilized in the WCS were verified as acceptable for usage in the space shuttle or other space vehicles

    Challenges in the development of the orbiter atmosphere revitalization subsystem

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    The space shuttle orbiter atmospheric revitalization subsystem provides thermal and contaminant control as well as total- and oxygen partial-pressure control of the environment within the orbiter crew cabin. Challenges that occurred during the development of this subsystem for the space shuttle orbiter are described. The design of the rotating hardware elements of the system (pumps, fans, etc.) required significant development to meet the requirements of long service life, maintainability, and high cycle-fatigue life. As a result, a stringent development program, particularly in the areas of bearing life and heat dissipation, was required. Another area requiring significant development was cabin humidity control and condensate collection

    Polish publications on jujutsu (1906-2020): bibliometric analysis

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    RESUMEN: El objetivo fue realizar un análisis bibliométrico de las publicaciones polacas sobre jujutsu centrado en los aspectos de productividad, asuntos y colaboración. Así, se consultaron la Biblioteca Nacional de Polonia, la Base de Revistas Científicas Polacas, la Web of Science y Scopus. Los resultados fueron filtrados y exportados a Excel 2016 para el análisis estadístico. Los documentos polacos sobre jujutsu alcanzaron los 123, publicados entre 1906 y 2020. Ciencias de la Vida fue el campo más representado, mientras que la colaboración predominó durante la última década. Cynarski fue el autor más productivo, mientras que Wojdat obtuvo el índice de colaboración más alto. Ido Movement for Culture fue el principal divulgador de estas publicaciones. En conclusión, las publicaciones polacas sobre jujutsu mostraron, durante el siglo XX, un predominio de libros técnicos escritos por autores individuales desde un abordaje de las Ciencias de la Vida, mientras que los artículos científicos escritos en colaboración y representando también otros enfoques han dominado en el siglo XXI.ABSTRACT: The aim was to perform a bibliometric analysis of Polish jujutsu publications focused on productivity, topics, and collaboration. Thus, the National Library of Poland, Polish Scientific Journals Database, Web of Science and Scopus were consulted. Results were filtered and exported to Excel 2016 for statistical analysis. 123 Polish jujutsu documents were published from 1906 to 2020. Life Sciences had the highest representation, while collaboration predominated during the last decade. Cynarski was the most productive author, while Wojdat achieved the highest collaboration index. Ido Movement for Culture was the main source for disseminating these publications. In conclusion, technical books written by single authors from a Life Sciences approach prevailed in Polish jujutsu publications during the 20th century, while scientific articles written in collaboration and also representing other approaches have prevailed in the 21st century

    Populations of doubled haploids for genetic mapping in hexaploid winter triticale.

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    To create a framework for genetic dissection of hexaploid triticale, six populations of doubled haploid (DH) lines were developed from pairwise hybrids of high-yielding winter triticale cultivars. The six populations comprise between 97 and 231 genotyped DH lines each, totaling 957 DH lines. A consensus genetic map spans 4593.9 cM is composed of 1576 unique DArT markers. The maps reveal several structural rearrangements in triticale genomes. In preliminary tests of the populations and maps, markers specific to wheat segments of the engineered rye chromosome 1R (RM1B) were identified. Example QTL mapping of days to heading in cv. Krakowiak revealed loci on chromosomes 2BL and 2R responsible for extended vernalization requirement, and candidate genes were identified. The material is available to all parties interested in triticale genetics

    An Electricity Market Model to Estimate the Marginal Value of Wind in an Adapting System

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    Abstract-In this paper a stochastic fundamental electricity market model is presented. The model's principle is cost minimization by determining the marginal system costs mainly as a function of available generation and transmission capacities, primary energy prices, plant characteristics and electricity demand. To obtain appropriate estimates of the marginal value of wind in an adapting system notably reduced efficiencies at part load, start-up costs and reserve power requirements are taken into account. The intermittency of wind is covered by a stochastic recombining tree and the system is considered to adapt on increasing wind integration over time by endogenous modeling of investments in thermal power plants. Exemplary results are presented for a German case study

    Improving health and well-being through community health champions: a thematic evaluation of a programme in Yorkshire and Humber.

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    AIMS: The contribution that lay people can make to the public health agenda is being increasingly recognised in research and policy literature. This paper examines the role of lay workers (referred to as 'community health champions') involved in community projects delivered by Altogether Better across Yorkshire and Humber. The aim of the paper is to describe key features of the community health champion approach and to examine the evidence that this type of intervention can have an impact on health. METHODS: A qualitative approach was taken to the evaluation, with two strands to gathering evidence: interviews conducted with different stakeholder groups including project leads, key partners from community and statutory sectors and community workers, plus two participatory workshops to gather the views of community health champions. Seven projects (from a possible 12) were identified to be involved in the evaluation. Those projects that allowed the evaluation team to explore fully the champion role (training, infrastructure, etc.) and how that works in practice as a mechanism for empowerment were selected. In total, 29 semi-structured interviews were conducted with project staff and partners, and 30 champions, varying in terms of age, gender, ethnicity and disability, took part in the workshops. RESULTS: Becoming a community health champion has health benefits such as increased self-esteem and confidence and improved well-being. For some champions, this was the start of a journey to other opportunities such as education or paid employment. There were many examples of the influence of champions extending to the wider community of family, friends and neighbours, including helping to support people to take part in community life. Champions recognised the value of connecting people through social networks, group activities, and linking people into services and the impact that that had on health and well-being. Project staff and partners also recognised that champions were promoting social cohesiveness and helping to integrate people into their community. CONCLUSIONS: The recent public health White Paper suggested that the Altogether Better programme is improving individual and community health as well as increasing social capital, voluntary activity and wider civic participation. This evaluation supports this statement and suggests that the community health champion role can be a catalyst for change for both individuals and communities

    Strategic Behavior in the German Balancing Energy Mechanism: Incentives, Evidence, Costs and Solutions

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    This paper investigates the incentives market participants have in the German electricity balancing mechanism. Strategic over- and undersupply positions are the result of existing stochastic arbitrage opportunities between the spot market and the balancing mechanism. This strategic behavior can be clearly identified in aggregate market data. These structural imbalances increase the need for reserve capacity, raise system security concerns, and thus burden significant cost on the customers. More effective market designs include changes in the balancing mechanism, the reserve capacity and the intraday spot markets

    Human Retinal Gene Therapy for Leber Congential Amaurosis Shows Advancing Retinal Degeneration Despite Enduring Visual Improvement

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    Leber congenital amaurosis (LCA) associated with retinal pigment epithelium-specific protein 65 kDa (RPE65) mutations is a severe hereditary blindness resulting from both dysfunction and degeneration of photoreceptors. Clinical trials with gene augmentation therapy have shown partial reversal of the dysfunction, but the effects on the degeneration are not known. We evaluated the consequences of gene therapy on retinal degeneration in patients with RPE65-LCA and its canine model. In untreated RPE65-LCA patients, there was dysfunction and degeneration of photoreceptors, even at the earliest ages. Examined serially over years, the outer photoreceptor nuclear layer showed progressive thinning. Treated RPE65-LCA showed substantial visual improvement in the short term and no detectable decline from this new level over the long term. However, retinal degeneration continued to progress unabated. In RPE65-mutant dogs, the first one-quarter of their lifespan showed only dysfunction, and there was normal outer photoreceptor nuclear layer thickness retina-wide. Dogs treated during the earlier dysfunction-only stage showed improved visual function and dramatic protection of treated photoreceptors from degeneration when measured 5–11 y later. Dogs treated later during the combined dysfunction and degeneration stage also showed visual function improvement, but photoreceptor loss continued unabated, the same as in human RPE65-LCA. The results suggest that, in RPE65 disease treatment, protection from visual function deterioration cannot be assumed to imply protection from degeneration. The effects of gene augmentation therapy are complex and suggest a need for a combinatorial strategy in RPE65-LCA to not only improve function in the short term but also slow retinal degeneration in the long term
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