6,307 research outputs found

    Finite-size scaling of the stochastic susceptible-infected-recovered model

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    The critical behavior of the stochastic susceptible-infected-recovered model on a square lattice is obtained by numerical simulations and finite-size scaling. The order parameter as well as the distribution in the number of recovered individuals is determined as a function of the infection rate for several values of the system size. The analysis around criticality is obtained by exploring the close relationship between the present model and standard percolation theory. The quantity UP, equal to the ratio U between the second moment and the squared first moment of the size distribution multiplied by the order parameter P, is shown to have, for a square system, a universal value 1.0167(1) that is the same as for site and bond percolation, confirming further that the SIR model is also in the percolation class

    Alternativas para gestão do bagaço de laranja

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    TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Agrárias. Curso de Agronomia.O objetivo da pesquisa foi buscar alternativas de atividades econômicas envolvendo a gestão do bagaço de laranja, resíduo da indústria de suco. A pesquisa foi feita através do método de revisão de literatura. O bagaço de laranja possui diversos benefícios na alimentação de ruminantes, pois reduz o risco de acidose ruminal. O bagaço de laranja in natura deve ser armazenado de forma adequada, para manter suas características nutricionais e livre de contaminação, na forma de silagem ou desidratado e peletizado. Os custos na produção da silagem do bagaço de laranja mostram que é uma ótima alternativa para os produtores, pois seu preço foi 4,5 vezes menor em comparação com a silagem de milho. A inclusão na alimentação humana, das fibras do bagaço de laranja em sorvetes e bolos reduziu o teor de lipídeos e valor calórico das receitas. Além do seu uso na alimentação animal e humana, se pode obter também biocombustíveis (bioóleo e etanol), e fazer utilização industrial de óleos essenciais e D-limoneno, que correspondem juntos a 2,71% da laranja inteira.The goal of this research was to find alternatives for economic activities involving the management of a juice’s industry residue, the Orange peel. This work was based on a literature review method. The orange peel has several benefits in ruminant feed as it reduces the risk of ruminal acidosis. In order to keep its nutritional characteristics and to be free of contamination, the fresh orange peel should be properly stored. It should be stored as silage or dehydrated and pelletized. Comparing costs with corn silage, the orange peel silage appears to be a great alternative for producers, being 4.5 times cheaper than corn silage. Adding orange peel’s fibers in human diet, in products such as ice creams and cakes, reduces the lipid rate and also lower the amount of calories in those recipes. In addition to the use in human diet and animal feed, from the orange peel, it is possible to obtain biofuel (ethanol and bio oil), also it can be made industrial use out of essential oils and the substance D-limonene which together corresponds to a percentage of 2.71% from the whole orange

    Visualizing test diversity to support test optimisation

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    Diversity has been used as an effective criteria to optimise test suites for cost-effective testing. Particularly, diversity-based (alternatively referred to as similarity-based) techniques have the benefit of being generic and applicable across different Systems Under Test (SUT), and have been used to automatically select or prioritise large sets of test cases. However, it is a challenge to feedback diversity information to developers and testers since results are typically many-dimensional. Furthermore, the generality of diversity-based approaches makes it harder to choose when and where to apply them. In this paper we address these challenges by investigating: i) what are the trade-off in using different sources of diversity (e.g., diversity of test requirements or test scripts) to optimise large test suites, and ii) how visualisation of test diversity data can assist testers for test optimisation and improvement. We perform a case study on three industrial projects and present quantitative results on the fault detection capabilities and redundancy levels of different sets of test cases. Our key result is that test similarity maps, based on pair-wise diversity calculations, helped industrial practitioners identify issues with their test repositories and decide on actions to improve. We conclude that the visualisation of diversity information can assist testers in their maintenance and optimisation activities

    The evolution, distribution and diversity of endogenous circoviral elements in vertebrate genomes

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    Circoviruses (family Circoviridae) are small, non-enveloped viruses that have short, single-stranded DNA genomes. Circovirus sequences are frequently recovered in metagenomic investigations, indicating that these viruses are widespread, yet they remain relatively poorly understood. Endogenous circoviral elements (CVe) are DNA sequences derived from circoviruses that occur in vertebrate genomes. CVe are a useful source of information about the biology and evolution of circoviruses. In this study, we screened 362 vertebrate genome assemblies in silico to generate a catalog of CVe loci. We identified a total of 179 CVe sequences, most of which have not been reported previously. We show that these CVe loci reflect at least 19 distinct germline integration events. We determine the structure of CVe loci, identifying some that show evidence of potential functionalization. We also identify orthologous copies of CVe in snakes, fish, birds, and mammals, allowing us to add new calibrations to the timeline of circovirus evolution. Finally, we observed that some ancient CVe group robustly with contemporary circoviruses in phylogenies, with all sequences within these groups being derived from the same host class or order, implying a hitherto underappreciated stability in circovirus-host relationships. The openly available dataset constructed in this investigation provides new insights into circovirus evolution, and can be used to facilitate further studies of circoviruses and CVe

    Physics teaching methods: an analysis on peer instruction and modeling instruction

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    There is a well known phenomenon related to physics students that concerns the difficulty that these have to understand conceptually what is being taught, since, not infrequently, these show bad results and learning difficulties. Based on this, the present article aim a literature review on different learning methods of physics teaching, among them, two in particular, the Peer Instruction and the Modeling Instruction. While in Peer Instruction the students meet with colleagues and discuss a certain theme among them, in most cases with conceptual testes, the Modeling Instruction is based on the use of interactive whiteboards and exposition of content through the student itself, as well as recommends experiments and other sources of pedagogical support. Many authors advocate that the student, even those with low performance in his classes, can learn better when they work in a interactive way or when they work with their peers. It is starting on this premise that studies in these subjects are based.There is a well known phenomenon related to physics students that concerns the difficulty that these have to understand conceptually what is being taught, since, not infrequently, these show bad results and learning difficulties. Based on this, the present article aim a literature review on different learning methods of physics teaching, among them, two in particular, the Peer Instruction and the Modeling Instruction. While in Peer Instruction the students meet with colleagues and discuss a certain theme among them, in most cases with conceptual testes, the Modeling Instruction is based on the use of interactive whiteboards and exposition of content through the student itself, as well as recommends experiments and other sources of pedagogical support. Many authors advocate that the student, even those with low performance in his classes, can learn better when they work in a interactive way or when they work with their peers. It is starting on this premise that studies in these subjects are based.

    Visual perception and user satisfaction in video see-through head-mounted displays: a mixed-methods evaluation

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    ObjectiveOur study addresses the challenges limiting the adoption of Extended Reality (XR) Head-Mounted Displays (HMDs), mainly focusing on device quality and cybersickness. We aim to investigate the impact of hardware and software on user experience and task performance while wearing Video See-Through (VST) HMDs. We employ a novel methodology designed to bridge the gaps identified in previous research.MethodsThis study uses a convergent mixed-methods approach, combining qualitative and quantitative data in a within-subjects evaluation involving 20 participants. This comprehensive evaluation examines visual perception, visual quality, and user experience through a range of tasks. Usability, comfort, and cybersickness are assessed, with insights derived from both user performance metrics and subjective measures collected through in-depth interviews and comments. The study includes three distinct HMDs—two prototypes (PD1 and PD2) and one commercial device (CD1)—to provide a broad analysis of the technology.FindingsOur findings reveal that while participants were generally satisfied with VST mode, their preferences varied across devices. CD1 was preferred for its realistic color representation and superior reading task performance due to its high-resolution display and camera. However, visual disturbances and temporal issues differed across devices, with CD1 exhibiting fewer artifacts when stationary but showing more disturbances when participants were moving. Participants found PD1 and PD2 more comfortable for extended use and fewer cybersickness symptoms, but they highlighted color and display resolution issues. These variations underscore the importance of considering both qualitative and quantitative measures in HMD evaluations.ConclusionThis mixed-methods evaluation emphasizes the limitations of relying solely on visual perception performance measures for VST HMDs. By integrating both quantitative and qualitative insights, we offer a more detailed evaluation framework to identify design flaws and user experience issues that quantitative metrics alone might miss. This methodology contributes to the field by illustrating how a mixed-methods approach provides a broader perspective on XR technology, guiding future improvements and enhancing VST adoption in future applications

    What Makes Research Software Sustainable? An Interview Study With Research Software Engineers

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    Software is now a vital scientific instrument, providing the tools for data collection and analysis across disciplines from bioinformatics and computational physics, to the humanities. The software used in research is often home-grown and bespoke: it is constructed for a particular project, and rarely maintained beyond this, leading to rapid decay, and frequent `reinvention of the wheel'. Understanding how to develop sustainable research software, such that it is suitable for future reuse, is therefore of interest to both researchers and funders, but how to achieve this remains an open question. Here we report the results of an interview study examining how research software engineers -- the people actively developing software in an academic research environment -- subjectively define software sustainability. Thematic analysis of the data reveals two interacting dimensions: \emph{intrinsic sustainability}, which relates to internal qualities of software, such as modularity, encapsulation and testability, and \emph{extrinsic sustainability}, concerning cultural and organisational factors, including how software is resourced, supported and shared. Research software engineers believe an increased focus on quality and discoverability are key factors in increasing the sustainability of academic research software

    Establishment of \u3ci\u3eSinoxylon anale\u3c/i\u3e Lesne (Coleoptera: Bostrichidae) in Brazil and its potential implications

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    Bostrichidae (Coleoptera) are a family of beetles with specialized xylophagous feeding habits that allow consumption of dry woody plant tissues. Bostrichids are often polyphagous and therefore pose a sig­nificant threat to many agricultural and forestry products, particularly in tropical regions. Bostrichids are commonly detected in solid wood packaging material at international ports of entry. Notably, Sinoxylon anale Lesne has been intercepted in wood crates and pallets worldwide and has now become established in Brazil. This paper reports the first documented establishment of S. anale in Brazil, being found both in domestic wood pallets and within native forest and monoculture. The origin of these populations remains uncertain, but introductions through infested wood packaging at ports of entry is a likely scenario. Similarly, the exact time of establishment is unknown. Given that S. anale adults are attracted to light and ethanol, trapping using light or ethanol could be used in monitoring surveys. This species typically infests dead or decaying woody material, and therefore does not pose a direct threat to healthy, live trees. Although more common in tropical regions, S. anale has exhibited some adaptability to temperate climates, which may allow it to spread across the tropical and subtropical regions of Brazil and potentially to other parts of South America

    Produção de manjericão na primavera verão em sistemas de cultivo e adubações

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    The cultivation of basil is intended for marketing the plant as a condiment and in the production of essential oil Factors such as growing season, fertilization and cultivation system influence the yield of the plant. The study aimed to produce basil (Ocimum basilicum L.) to grow Cinnamon simultaneously in the field and in a protected place/greenhouse, in the spring - summer season using mineral, organomineral and organic fertilization in order to evaluate these isolated factors or the interaction between them in the production, content and composition of essential oil. The experiment was carried out in the city of Uberlândia on the experimental farm called Glória between April 2017 and July 2017. The experimental design used was the randomized block (DBC), in a factory scheme (2 x 4), in two environments (greenhouse and field) e four types of fertilization, with a total of 8 treatments, in 4 repetitions. The cultivation used was Cinnamon, and the experiments were conducted and installed simultaneously in the field and greenhouse. The harvest took place when the plants were in full bloom. The variables analyzed were plant height, dry and fresh mass of leaves and flowers, content and composition of essential oil. For the averages of SPAD index, plant height, leaf length and width, there was no interaction for the evaluated factors. Plants fertilized with organic sources and grown in a greenhouse showed superior yield in relation to field cultivation for the variables fresh mass of leaves and flowers, dry mass of leaves and flowers and essential oil yield. The main compounds found in the essential oil wew linalool and (E) –cinnamate, grown in the field and greenhouse.Pesquisa sem auxílio de agências de fomentoTrabalho de Conclusão de Curso (Graduação)O cultivo de manjericão é destinado para comercialização da planta como condimento e na produção de óleo essencial. Fatores como época de cultivo, adubação e sistema de cultivo influenciam no rendimento da planta. O trabalho teve como objetivo produzir manjericão (Ocimum basilicum L.) cultivar Cinnamon de forma simultânea em campo e em ambiente protegido, na época primavera-verão utilizando adubação mineral, organomineral e orgânica com a finalidade de avaliar esses fatores isolados ou a interação entre eles na produção, teor e composição do óleo essencial. O experimento foi executado no município de Uberlândia na fazenda experimental do Glória entre os meses de abril de 2017 e julho de 2017. O delineamento experimental utilizado foi o de blocos casualizados (DBC), em esquema fatorial (2 x 4), em dois ambientes (campo e ambiente protegido) e quatro tipos de adubação, com o total de 8 tratamentos, em 4 repetições. A cultivar utilizada foi a Cinnamon, e os experimentos foram conduzidos e instalados simultaneamente no campo e estufa. A colheita aconteceu quando as plantas estavam em pleno florescimento. As variáveis analisadas foram altura de planta, massa seca e fresca de folhas e flores, teor e composição do óleo essencial. Para as médias de índice SPAD, altura de planta, comprimento e largura de folhas não houve interação para os fatores avaliados. As plantas adubadas com fonte orgânica e cultivadas em ambiente protegido apresentaram rendimento superior em relação ao cultivo em campo para as variáveis: massa fresca de folhas e flores, massa seca de folhas e flores e rendimento de óleo essencial. Os principais compostos encontrados no óleo essencial foram o linalol e (E) – cinamato, cultivados em campo e estufa
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