1,289 research outputs found

    The importance of body mass normalisation for ultrasound measurements of the morphology of oblique abdominis muscles: the effect of age, gender, and sport practice

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    Some studies have not considered body mass as a confounder in analysis of oblique abdominis muscles (OAM) (including the oblique externus [OE] and oblique internus [OI]), which may have led to improper interpretation of results. To assess the differences in the effect of age, gender, and physical activity between normalised for body mass and actual values of the OAM as well as to establish the effect of age, gender, and physical activity on normalised for body mass OAM thicknesses in adolescents. A real-time ultrasound was used to obtain images of the OAM. Body mass normalisation for OAM thicknesses was performed with allometric scaling and the following equations: Allometric-scaled OE = OE thickness/body mass0.88; Allometric-scaled OI = OI thickness/body mass0.72. Analysis showed that boys have significantly thicker OAM than girls, and those who practise sports have thicker OAM than non-active individuals. For allometric-scaled OAM, there was only a significant gender effect, where boys have thicker allometric-scaled OAM than girls. There was a significant correlation between participants’ age and the actual value of the OAM. The correlations between age and allometric-scaled OAM were insignificant. An analysis of OAM without body mass normalisation can lead to improper interpretation of study results. Thus, future studies should analyse OE and OI thickness measurements after normalisation rather than actual values. In the adolescent population, there is no effect of age and physical activity on allometric-scaled OAM; males have thicker allometric-scaled OAM than females. (Folia Morphol 2018; 77, 1: 123–130

    Colouring steiner quadruple systems

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    AbstractA Steiner quadruple system of order ν (briefly SQS(ν)) is a pair (X, B), where |X| = ν and B is a collection of 4-subsets of X, called blocks, such that each 3-subset of X is contained in a unique block of B. A SQS(ν) exists iff ν ≡ 2, 4 (mod 6) or ν = 0, 1 (the admissible integers). The chromatic number of (X, B) is the smallest m for which there is a map ϕ: X → Zm such that |ϕ(β)| ⩾ 2 for all β ϵ B. In this paper it is shown that for each m ⩾ 6 there exists νm such that for all admissible ν ⩾ νm there exists an m-chromatic SQS(ν). For m = 4, 5 the same statement is proved for admissible ν with the restriction that ν ≢ 2 (mod 12)

    Effects of Applying WC/C Protective Coating on Structural Elements Working in Cavitation Environment

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    When designing the individual subassemblies of machines or entire devices one has to draw special attention to the resistance of the elements working there, to tribological damages (mechanical, fatigue, adhesion, abrasion, hydrogen and other damages) as well as to non-tribological damages (corrosion, diffusion, cavitation, erosion, ablation and others). The main purpose of this publication was to examine the influence of the applied WC/C protective coating deposited by PVD method on the cavitation wear processes of construction elements working in difficult cavitation environment. Two steels were selected for detailed examinations in the conditions of cavitation wear. The first one is P265GH steel commonly used for pressure devices working at elevated temperatures, with a ferritic-pearlitic structure, and the other derives from a group of stainless steels, i.e. chromium-nickel X2CrNi18-9 (304L) steel with an austenitic structure. The tests results obtained allow to conclude that the application of special low-friction protective coatings allows to reduce costs associated with selection of engineering materials for a substrate of constructional elements working in a cavitation wear environment. P265GH steel is 4 times cheaper than austenitic chromium-nickel X2CrNi18-9 steel, and if a WC/C coating is deposited in this case, this considerably extends the working time of such elements in a cavitation environment

    A Reputation Economy: Results from an Empirical Survey on Academic Data Sharing

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    Academic data sharing is a way for researchers to collaborate and thereby meet the needs of an increasingly complex research landscape. It enables researchers to verify results and to pursuit new research questions with "old" data. It is therefore not surprising that data sharing is advocated by funding agencies, journals, and researchers alike. We surveyed 2661 individual academic researchers across all disciplines on their dealings with data, their publication practices, and motives for sharing or withholding research data. The results for 1564 valid responses show that researchers across disciplines recognise the benefit of secondary research data for their own work and for scientific progress as a whole-still they only practice it in moderation. An explanation for this evidence could be an academic system that is not driven by monetary incentives, nor the desire for scientific progress, but by individual reputation-expressed in (high ranked journal) publications. We label this system a Reputation Economy. This special economy explains our findings that show that researchers have a nuanced idea how to provide adequate formal recognition for making data available to others-namely data citations. We conclude that data sharing will only be widely adopted among research professionals if sharing pays in form of reputation. Thus, policy measures that intend to foster research collaboration need to understand academia as a reputation economy. Successful measures must value intermediate products, such as research data, more highly than it is the case now

    Avoiding Patterns in the Abelian Sense

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    We classify all 3 letter patterns that are avoidable in the abelian sense. A short list of four letter patterns for which abelian avoidance is undecided is given. Using a generalization of Zimin words we deduce some properties of ω-words avoiding these patterns.Research of both authors supported by NSERC Operating Grants.https://www.cambridge.org/core/journals/canadian-journal-of-mathematics/article/avoiding-patterns-in-the-abelian-sense/42148B0781A38A6618A537AAD7D39B8

    Introduction to Physics

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    This Grants Collection for Introduction to Physics was created under a Round Two ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/physics-collections/1000/thumbnail.jp

    Why Czech Parliamentary Party Groups Vote Less Unitedly. The Role of Frequent Voting and Big Majorities in Passing Bills

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    The article aims to explain voting unity in the Chamber of Deputies of the Parliament of the Czech Republic based on data from the years 1998-2002. It introduces the basic terminology & theoretical framework used in literature on the behaviour of parties in parliament & the basic institutional rules that should result in the unity of political parties in the Czech parliament. It then presents the data used to measure the unity of Czech parliamentary party groups. The initial assumption that specific institutional factors found in parliament & in political parties would lead to greater PPG unity in the Czech Republic was not confirmed. Although the institutional incentives are similar to those in Western European countries, they do not secure the same level of voting unity in Czech PPGs. The authors conclude that the relatively low party unity is caused by the size of the voting coalitions that pass individual bills
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