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The rice leaf, combining the surface properties of lotus leaves and shark skin, presents outstanding superhydrophobic properties motivating its biomimesis. We created a novel biomimetic rice-leaf superhydrophobic surface by a three-level hierarchical structure, using for a first time stereolithographic (SLA) 3D printed channels (100µm width) with an intrinsic roughness from the printing filaments (10µm), and coated with TiO2 nanoparticles (22 and 100nm). This structure presents a maximum advancing contact angle of 165° characterized by lower both anisotropy and hysteresis contact angles than other 3D printed surfaces, due to the presence of air pockets at the surface/water interface (Cassie-Baxter state). Dynamic water-drop tests show that the biomimetic surface presents self-cleaning, which is reduced under UV-A irradiation. The biomimetic surface further renders an increased floatability to 3D printed objects meaning a drag-reduction due to reduced water/solid contact area. Numerical simulations of a channel with a biomimetic wall confirm that the presence of air is essential to understand our results since it increases the average velocity and decreases the friction factor due to the presence of a wall-slip velocity. Our findings show that SLA 3D printing is an appropriate approach to develop biomimetic superhydrophobic surfaces for future applications in anti-fouling and drag-reduction devices.

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Regulatory mechanisms range from a single level of control in simple metazoans to multi-level hierarchical control networks in higher animals. Organismal regulation encompasses homeostatic and circadian networks that are interconnected, with no documented exceptions. The epigenetic clock is a highly accurate biomarker of age in humans, defined by a mathematical algorithm based on the methylation of a subset of age-related CpG sites on DNA. Experimental evidence suggests the existence of an underlying regulatory mechanism. By analogy with other integrative systems as the neuroendocrine-immune network and the circadian clocks, a hierarchical organization in the control of the ticking rate of the epigenetic clock is hypothesized here. The hierarchical organization of the neuroendocrine, immune and circadian systems is briefly reviewed. This is followed by a brief review of the epigenetic clock at cell level. Finally, different lines of indirect evidence, consistent with the existence of a central pacemaker controlling the ticking rate of the epigenetic clock at organismal level are discussed. The concluding remarks put the hierarchical model proposed for the control of the clock into an evolutionary perspective. Within this perspective, the present hypothesis is intended as a conceptual outline based on designs consistently favored by evolution in higher animals.

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PURPOSE: In the present study, we aimed to integrate unidimensional and multidimensional perspectives of the construct of the fear of personal death (FOPD). It has been assumed that (a) there is one general factor of FOPD, reflecting the unidimensional perspective and that (b) FOPD assumes a hierarchical structure reflecting the multidimensional perspective. METHODS: We administered the Death and Dying Anxiety Inventory (FVTS, Ochsmann, 1993) to 1217 Polish participants (602 women and 615 men) aged between 18 and 89 (MAge = 31.13; SDAge = 12.65). RESULTS: The results of the bi-factor model of the confirmatory factor analysis proved the existence of a FOPD general factor. Using the bass-ackwards approach, we provided evidence on the hierarchical structure of FOPD, which stresses that specific types of FOPD distinguished in the FVTS, which, on a higher level, make up the factors of threats to self-fulfilling existence, threats to well-being and threats of physical destruction, which in turn depend on the subject's perspective: the physical self and/or the symbolic self. CONCLUSION: The current study demonstrates that unidimensional and multidimensional approaches to FOPD do not necessarily exclude one another. The unidimensional approach to FOPD seems to be most appropriate for studying the intensity of FOPD, while the multidimensional approach seems to be more suitable for studying the individual differences in how people give meaning to FOPD.

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Abstract Purpose In the present study, we aimed to integrate unidimensional and multidimensional perspectives of the construct of the fear of personal death (FOPD). It has been assumed that (a) there is one general factor of FOPD, reflecting the unidimensional perspective and that (b) FOPD assumes a hierarchical structure reflecting the multidimensional perspective. Methods We administered the Death and Dying Anxiety Inventory (FVTS, Ochsmann, 1993) to 1217 Polish participants (602 women and 615 men) aged between 18 and 89 ( M Age = 31.13; SD Age = 12.65). Results The results of the bi-factor model of the confirmatory factor analysis proved the existence of a FOPD general factor. Using the bass-ackwards approach, we provided evidence on the hierarchical structure of FOPD, which stresses that specific types of FOPD distinguished in the FVTS, which, on a higher level, make up the factors of threats to self-fulfilling existence, threats to well-being and threats of physical destruction, which in turn depend on the subject's perspective: the physical self and/or the symbolic self. Conclusion The current study demonstrates that unidimensional and multidimensional approaches to FOPD do not necessarily exclude one another. The unidimensional approach to FOPD seems to be most appropriate for studying the intensity of FOPD, while the multidimensional approach seems to be more suitable for studying the individual differences in how people give meaning to FOPD.

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Este estudo tem como objectivo principal a análise da estrutura hierárquica do autoconceito em adolescentes e, adicionalmente, a comparação dessa estrutura em alunos com e sem repetência no seu passado escolar. Participaram no estudo 943 alunos portugueses do 7º, 9º e 11º ano de escolaridade, que responderam a uma escala de autoconceito e de auto-estima. Os resultados obtidos sustentam a ideia de uma organização hierárquica do autoconceito e um modelo que subdivide o autoconceito em quatro factores de ordem superior. Os resultados sugerem, ainda, uma associação entre a dimensão comportamento e diferentes dimensões de ordem superior, nomeadamente as duas dimensões do autoconceito académico e o autoconceito social. Os resultados divergem quando tomamos alunos com maior e menor sucesso escolar, justificando maior atenção na investigação e na intervenção a este aspecto.

The main goal of this research is to analyze the hierarchical structure of self-concept in adolescents and, additionally, to compare this structure in students who have failed in their academic career and in those who have not. Nine hundred and forty-three Portuguese students from the 7th, 9th and 11th grades participated in the research. They completed self-concept and self-esteem scales. Results support the assertion that self-concept is hierarchically structured, and also support a model that subdivides self-concept into four higher order factors. Results also suggest an association between the behavioral dimension and various different higher order dimensions, namely, the two academic self-concept dimensions and the social self-concept one. However, they show divergences when the structure of self-concept between achievers and underachievers is compared. This aspect needs to be examined with greater attention on future researches and interventions.

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Este estudo tem como objectivo principal a análise da estrutura hierárquica do autoconceito em adolescentes e, adicionalmente, a comparação dessa estrutura em alunos com e sem repetência no seu passado escolar. Participaram no estudo 943 alunos portugueses do 7º, 9º e 11º ano de escolaridade, que responderam a uma escala de autoconceito e de auto-estima. Os resultados obtidos sustentam a ideia de uma organização hierárquica do autoconceito e um modelo que subdivide o autoconceito em quatro factores de ordem superior. Os resultados sugerem, ainda, uma associação entre a dimensão comportamento e diferentes dimensões de ordem superior, nomeadamente as duas dimensões do autoconceito académico e o autoconceito social. Os resultados divergem quando tomamos alunos com maior e menor sucesso escolar, justificando maior atenção na investigação e na intervenção a este aspecto.(AU)

The main goal of this research is to analyze the hierarchical structure of self-concept in adolescents and, additionally, to compare this structure in students who have failed in their academic career and in those who have not. Nine hundred and forty-three Portuguese students from the 7th, 9th and 11th grades participated in the research. They completed self-concept and self-esteem scales. Results support the assertion that self-concept is hierarchically structured, and also support a model that subdivides self-concept into four higher order factors. Results also suggest an association between the behavioral dimension and various different higher order dimensions, namely, the two academic self-concept dimensions and the social self-concept one. However, they show divergences when the structure of self-concept between achievers and underachievers is compared. This aspect needs to be examined with greater attention on future researches and interventions.(AU)

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